SQA of finite element method (FEM) codes used for analyses of pit storage/transport packages

Energy Technology Data Exchange (ETDEWEB)

Russel, E. [Lawrence Livermore National Lab., CA (United States)

1997-11-01

This report contains viewgraphs on the software quality assurance of finite element method codes used for analyses of pit storage and transport projects. This methodology utilizes the ISO 9000-3: Guideline for application of 9001 to the development, supply, and maintenance of software, for establishing well-defined software engineering processes to consistently maintain high quality management approaches.

Physico-chemical characterization of grain dust in storage air of Bangalore.

Science.gov (United States)

Mukherjee, A K; Nag, D P; Kakde, Y; Babu, K R; Prdkash, M N; Rao, S R

1998-06-01

An Anderson personal cascade impactor was used to study the particle mass size distribution in the storage air of two major grain storage centers in Bangalore. Dust levels in storage air as well as the personal exposures of workers were determined along with a detailed study on the particle size distribution. Protein and carbohydrate content of the dust were also determined respectively in the phosphate buffer saline (PBS) and water extracts by using the standard analytical techniques. Personal exposures in both of the grain storage centers have been found to be much above the limit prescribed by ACGIH (1995-96). But the results of particle size analysis showed a higher particle mass distribution in the non-respirable size range. The mass median diameters (MMD) of the storage air particulate of both the centers were found to be beyond the respirable range. Presence of protein and carbohydrate in the storage air dust is indicative of the existence of glyco-proteins, mostly of membrane origin.

Effects of storage temperature on the fungal and chemical spoilage of maize grains and flour

International Nuclear Information System (INIS)

Akhter, T.; Sattar, A.; Khan, I.; Ahmed, A.

1989-01-01

The chemical and fungal spoilage of maize grains and flour of Sarhad White and Sarhad Yellow varieties in relation to time temperature (10 C, 15 C, 20 C and room (30-56 C) storage period at 8-12 months was studied. The results showed that total fungal counts and percent infestation markedly increased with advanced storage and increased temperature. Percentage germination generally decreased during extended storage. Peroxide values of both the grain and flour increased with increasing temperature and storage time. At the end of one year storage the total fungal counts in the grain and flour of Sarhad White and Sarhad Yellow ranged 13.6x10/sup 12/ - 20.0x10/sup 13/ and Yellow ranged 17.1x10/sup 13/ - 22.1x10/sup 14/ respectively. germination and infestation percentage of the grains of Sarhad White and Sarhad Yellow ranged 76-78% and 96-99%. The peroxide value ranged 6.6-7.0 and 6.4-6.8 meg/Kg in the grain and flour of Sarhad White respectively after one year storage. There was more fungal infestation, fungal counts and peroxidation in the grain and flour Sarhad Yellow than that of Sarhad White. (author)

The influence of external conditions on the grain storage process

Directory of Open Access Journals (Sweden)

O. A. Orlovtseva

2016-01-01

Full Text Available .High quality grain - a pledge of his safety, reduce losses and the costs of storage. Wheat is the main source of human nutrition. Elements contained in wheat perform a fundamental role in human life. Storing grain quality is an urgent task. One of the labor-intensive operations in this process is the correct placement of parties in wheat granary and timely monitoring of key parameters (humidity and temperature. In this regard, we consider methods for determining the intensity of the grain breathing method for determining the moisture content and temperature of the grain of wheat. Humidity was determined by electrical hygrometer. To measure the temperature of wheat used mercury thermometer. In analyzing the breathing wheat energy depending on the humidity it was found that the intensity of respiration increasingly affects humidity increase than an increase in temperature. As objects of study used wheat varieties: Hordeiforme 432 and Multiroom 321. According to the results obtained in the study plot the respiratory activity of the grain from moisture. According to the schedules we concluded that the sharp increase in wheat breathing energy occurs with increasing moisture content to a value of more than 15%. Just found out that in addition to breathing in highly humid grain appears vital functions of harmful microorganisms, which under the influence of grain rots and becomes stale. Thus, ho-well-organized and skilled observation, the correct analysis of the obtained data allow to bring the maximum reduction in spending of dry matter and therefore achieve lower grain weight loss during storage.

Location Optimization for Biomass Trigeneration System with Pit Thermal Energy Storage: the Case of the City of Petrinja

DEFF Research Database (Denmark)

Ćosić, B.; Dominkovic, Dominik Franjo; Ban, M.

2015-01-01

The combined production of electricity, heat and cold in biomass trigeneration power plants integrated with seasonal pit thermal energy storage ensures maximum utilization of biomass resources and at the same time reduction of variable operation costs of the system. Beside optimal size of trigene...

Comparative evaluation of six storage methods for postharvest preservation of cowpea grain

KAUST Repository

Baoua, I. B.

2012-04-01

Several technologies reputedly minimize losses of stored cowpea grain to bruchid beetles on low resource farms in Africa. Side by side comparison of these different postharvest storage methods can provide the basis for deciding which performs best. We compared six different technologies for cowpea storage: (1) grain mixed with ash; (2) mixed with sand; (3) fumigated with phostoxin; (4) admixed with the stems and leaves of . Boscia senegalensis (Pers) Lam ex Poir, a potential botanical insecticide; (5) disinfested using a solar heater, and; (6) hermetically sealed in triple-layer plastic bags. Sampling was done at thirty-day intervals over five months of storage. Counts were made of (i) adult emergence holes, (ii) dead larvae and (iii) surviving bruchid larvae and adults. Controls, which consisted of infested cowpea grain stored in cloth bags, were damaged extensively. . Boscia senegalensis-treated grain suffered similar severe damage. All other treatments suppressed bruchid population increases as was evident from the much lower counts of emergence holes and lower numbers of surviving or dead insects. © 2012 Elsevier Ltd.

Comparative evaluation of six storage methods for postharvest preservation of cowpea grain

KAUST Repository

Baoua, I. B.; Amadou, L.; Margam, V.; Murdock, L. L.

2012-01-01

Several technologies reputedly minimize losses of stored cowpea grain to bruchid beetles on low resource farms in Africa. Side by side comparison of these different postharvest storage methods can provide the basis for deciding which performs best. We compared six different technologies for cowpea storage: (1) grain mixed with ash; (2) mixed with sand; (3) fumigated with phostoxin; (4) admixed with the stems and leaves of . Boscia senegalensis (Pers) Lam ex Poir, a potential botanical insecticide; (5) disinfested using a solar heater, and; (6) hermetically sealed in triple-layer plastic bags. Sampling was done at thirty-day intervals over five months of storage. Counts were made of (i) adult emergence holes, (ii) dead larvae and (iii) surviving bruchid larvae and adults. Controls, which consisted of infested cowpea grain stored in cloth bags, were damaged extensively. . Boscia senegalensis-treated grain suffered similar severe damage. All other treatments suppressed bruchid population increases as was evident from the much lower counts of emergence holes and lower numbers of surviving or dead insects. © 2012 Elsevier Ltd.

Changes in energy metabolism accompanying pitting in blueberries stored at low temperature.

Science.gov (United States)

Zhou, Qian; Zhang, Chunlei; Cheng, Shunchang; Wei, Baodong; Liu, Xiuying; Ji, Shujuan

2014-12-01

Low-temperature storage and transport of blueberries is widely practiced in commercial blueberry production. In this research, the storage life of blueberries was extended at low temperature, but fruit stored for 30 d at 0°C pitted after 2d at room-temperature. Fruit cellular structure and physiological parameters accompanying pitting in blueberries were changed. The objective of this research was to characterise properties of energy metabolism accompanying pitting in blueberries during storage, including adenosine phosphates and mitochondrial enzymes involved in stress responses. Physiological and metabolic disorders, changes in cell ultrastructure, energy content and ATPase enzyme activity were observed in pitting blueberries. Energy shortages and increased activity of phenylalanine ammonia lyase (PAL) and lipoxygenase (LOX) were observed in fruit kept at shelf life. The results suggested that sufficient available energy status and a stable enzymatic system in blueberries collectively contribute to improve chilling tolerance, thereby alleviating pitting and maintaining quality of blueberry fruit in long-term cold storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

THE IMPACT OF ORGANIZATIONAL AND TECHNOLOGICAL FACTORS ON THE EXPENSE STRUCTURE OF THE GRAIN STORAGES CONSTRUCTION ENTERPRISE

Directory of Open Access Journals (Sweden)

MENEJLYUK A. I.

2016-12-01

Full Text Available Formulation of the problem. The deficit of grain storage capacities in Ukraine is about 15-20 mln. tons. Specific conditions of the realization of grain storage construction projects require systemic research to improve the efficiency of organizational and technological solutions in the management of specialized companies, to reduce costs of construction works and to increase the profit margin. Purpose. Research changes in the structure and the amount of the total production costs of the grain storage construction enterprise under the influence of organizational and technological factors. Conclusion. The account of features of grain storage construction, as well as developed research methodology: have resulted in analysis and the construction of a computer model of the operating activity of the grain storage construction enterprise; have allowed exploring experimental and statistical regularities of indicators changes of such operating activity from the influence of organizational and technological factors.

Preliminary quantification of a shape model for etch-pits formed during natural weathering of olivine

International Nuclear Information System (INIS)

Nowicki, M. Anna; Velbel, Michael A.

2011-01-01

Many etch-pits on olivine grains occur as a pair of cone-shaped pits sharing a base, which consequently appear as diamond-shaped etch-pits in cross-section. Quantitative image analysis of back-scattered electron images establishes empirical dimensions of olivine etch-pits in naturally weathered samples from Hawaii and North Carolina. Images of naturally etched olivine were acquired from polished thin-sections by scanning electron microscopy. An average cone-radius-to-height ratio (r:h) of 1.78 was determined for diamond-shaped cross-sections of etch-pits occurring in naturally weathered olivine grains, largely consistent with previous qualitative results. Olivine etch-pit shape as represented by r:h varies from slightly more than half the average value to slightly more than twice the average. Etch-pit shape does not appear to vary systematically with etch-pit size.

Work Plan: Phase II Investigation at the Former CCC/USDA Grain Storage Facility in Montgomery City, Missouri

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, Lorraine M [Argonne National Lab. (ANL), Argonne, IL (United States)

2012-05-01

From September 1949 until September 1966, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) leased property at the southeastern end of Montgomery City, Missouri, for the operation of a grain storage facility. During this time, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the private grain storage industry to preserve grain in their facilities.

Mobile Pit verification system design based on passive special nuclear material verification in weapons storage facilities

Energy Technology Data Exchange (ETDEWEB)

Paul, J. N.; Chin, M. R.; Sjoden, G. E. [Nuclear and Radiological Engineering Program, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 770 State St, Atlanta, GA 30332-0745 (United States)

2013-07-01

A mobile 'drive by' passive radiation detection system to be applied in special nuclear materials (SNM) storage facilities for validation and compliance purposes has been designed through the use of computational modeling and new radiation detection methods. This project was the result of work over a 1 year period to create optimal design specifications to include creation of 3D models using both Monte Carlo and deterministic codes to characterize the gamma and neutron leakage out each surface of SNM-bearing canisters. Results were compared and agreement was demonstrated between both models. Container leakages were then used to determine the expected reaction rates using transport theory in the detectors when placed at varying distances from the can. A 'typical' background signature was incorporated to determine the minimum signatures versus the probability of detection to evaluate moving source protocols with collimation. This established the criteria for verification of source presence and time gating at a given vehicle speed. New methods for the passive detection of SNM were employed and shown to give reliable identification of age and material for highly enriched uranium (HEU) and weapons grade plutonium (WGPu). The finalized 'Mobile Pit Verification System' (MPVS) design demonstrated that a 'drive-by' detection system, collimated and operating at nominally 2 mph, is capable of rapidly verifying each and every weapon pit stored in regularly spaced, shelved storage containers, using completely passive gamma and neutron signatures for HEU and WGPu. This system is ready for real evaluation to demonstrate passive total material accountability in storage facilities. (authors)

Studies in pitting corrosion on archaeological bronzes. Copper

International Nuclear Information System (INIS)

Bresle, Aa.; Saers, J.; Arrhenius, B.

1983-01-01

Copper has been proposed as a canister material for use in the long-term storage of radioactive waste from nuclear power reactors. The storage period has been set to at least 100 000 years, during which time the copper cylinders must remain intact so that the contained waste has no possibility of leaking out. In this work, the pitting factor in archaelogical copper objects have been determined. The absolute values of the pitting factor obtained are generally very low. In the case of the most thoroughly studied material the pitting factor is only slightly more than three units. Nor does the native copper, with a presumed burial period of about 8000 years, exhibit particularly high values. In summary, it can therefore be concluded that the present study does not provide support for the assumption of extremely high pitting factors in copper-base material that has been buried for periods of several millenia. (G.B.)

Mycoflora of grain maize ( Zea mays L.) Stored in traditional storage ...

African Journals Online (AJOL)

Mycoflora of grain maize ( Zea mays L.) Stored in traditional storage containers ( Gombisa and sacks) in selected woredas ... PROMOTING ACCESS TO AFRICAN RESEARCH ... African Journal of Food, Agriculture, Nutrition and Development.

Evaluation of Range-based Methods for Localization in Grain Storages

DEFF Research Database (Denmark)

Juul, Jakob Pilegaard; Green, Ole; Jacobsen, Rune Hylsberg

2016-01-01

sensor nodes embedded in a grain storage. A path loss model that takes into account the temperature and moisture content of the grain at each sensor node was used for estimating distance based on received signal strength. The average error of the position estimates was 6.3 m. Tests using near......-field electromagnetic ranging were performed to evaluate the performance of the method. It was found that the experimental setup worked best between 2 - 7 m where the average error was 4.9% of the actual distance....

Food Prices and Climate Extremes: A Model of Global Grain Price Variability with Storage

Science.gov (United States)

Otto, C.; Schewe, J.; Frieler, K.

2015-12-01

Extreme climate events such as droughts, floods, or heat waves affect agricultural production in major cropping regions and therefore impact the world market prices of staple crops. In the last decade, crop prices exhibited two very prominent price peaks in 2007-2008 and 2010-2011, threatening food security especially for poorer countries that are net importers of grain. There is evidence that these spikes in grain prices were at least partly triggered by actual supply shortages and the expectation of bad harvests. However, the response of the market to supply shocks is nonlinear and depends on complex and interlinked processes such as warehousing, speculation, and trade policies. Quantifying the contributions of such different factors to short-term price variability remains difficult, not least because many existing models ignore the role of storage which becomes important on short timescales. This in turn impedes the assessment of future climate change impacts on food prices. Here, we present a simple model of annual world grain prices that integrates grain stocks into the supply and demand functions. This firstly allows us to model explicitly the effect of storage strategies on world market price, and thus, for the first time, to quantify the potential contribution of trade policies to price variability in a simple global framework. Driven only by reported production and by long--term demand trends of the past ca. 40 years, the model reproduces observed variations in both the global storage volume and price of wheat. We demonstrate how recent price peaks can be reproduced by accounting for documented changes in storage strategies and trade policies, contrasting and complementing previous explanations based on different mechanisms such as speculation. Secondly, we show how the integration of storage allows long-term projections of grain price variability under climate change, based on existing crop yield scenarios.

The effect of precipitated carbides on the pitting corrosion of 304 stainless steel

International Nuclear Information System (INIS)

Kwak, Jai-Hyun; Kim, Kwan-Hun

1985-01-01

In order to investigate the relation between the pitting corrosion and precipitated carbides, the heat treatment of specimens was carried out in two ways: Solution treatment and carbides precipitation treatment. The experiment was focused on the polarization curves of specimens immersed in HCL solution and on the microscopic analysis of the corroded specimens through a potentiodynamic method. It was found out that the intergranular and pitting corrosion occurred remarkably in 0.1N and 1N KCL solution when carbides were precipitated around the grain boundary of the 304 stain steel. The intergranular corrosion was noticed in the region of passivation and the pitting was prominent in the region of passivation break-down. The distribution of pits on the solution treated 304 stainless steel was random, while that of pits on carbides precipitated specimen was concentrated around the grain boundary in 0.1N and 1N HCL solution. It was ascertained that the pitting resistance of the solution treated 304 stainless steel was better than that of carbides precipitated specimen. (Author)

Development of Seasonal Storage in Denmark

DEFF Research Database (Denmark)

Heller, Alfred

2000-01-01

National survey on seasonal (thermal, large-scale) storage activities in Denmark. A storage programme under the Danish Energy Agency. Programme background, objectives, activities, projects and results.Technologies presented: Pit water storage, gravel water storage with pipe heat exchangers, lining...... materials for pit and lid designs....

Metallography of pitted aluminum-clad, depleted uranium fuel

International Nuclear Information System (INIS)

Nelson, D.Z.; Howell, J.P.

1994-01-01

The storage of aluminum-clad fuel and target materials in the L-Disassembly Basin at the Savannah River Site for more than 5 years has resulted in extensive pitting corrosion of these materials. In many cases the pitting corrosion of the aluminum clad has penetrated in the uranium metal core, resulting in the release of plutonium, uranium, cesium-137, and other fission product activity to the basin water. In an effort to characterize the extent of corrosion of the Mark 31A target slugs, two unirradiated slug assemblies were removed from basin storage and sent to the Savannah River Technology Center for evaluation. This paper presents the results of the metallography and photographic documentation of this evaluation. The metallography confirmed that pitting depths varied, with the deepest pit found to be about 0.12 inches (3.05 nun). Less than 2% of the aluminum cladding was found to be breached resulting in less than 5% of the uranium surface area being affected by corrosion. The overall integrity of the target slug remained intact

The Influence of Radiation on Pit Solution Chemistry as it Pertains to the Transition from Metastable to Stable Pitting in Steels

International Nuclear Information System (INIS)

Galuszka-Muga, Barbara; Muga, Luis M.

2006-01-01

Previous work relevant to current efforts is summarized. A description of an improved version of a new electrochemical probe, the ArtPit, is given. The distinct feature of the probe for investigating metastable pitting of carbon steels is specified and compared to other approaches. The electrochemical response of the ArtPit under the gamma irradiation and elevated temperature conditions that occur at high level waste (HLW) storage tanks is presented. In particular, the Tafel slope determinations and chemical analyses of the ArtPit confined volume electrolyte are described. Based on results a possible approach for reducing the corrosion rate of HLW tank walls is suggested. Additional statistical analysis of the occurrence of short duration (passivated pits) and long term (stable pitting) electrochemical pulses (current surges) during exposure confirm that radiation enhances the occurrence of both more and smaller sized pits due to increased likelihood of repassivation

Changes in properties of starch isolated from whole rice grains with brown, black, and red pericarp after storage at different temperatures.

Science.gov (United States)

Ziegler, Valmor; Ferreira, Cristiano Dietrich; Goebel, Jorge Tiago Schwanz; El Halal, Shanise Lisie Mello; Santetti, Gabriela Soster; Gutkoski, Luiz Carlos; Zavareze, Elessandra da Rosa; Elias, Moacir Cardoso

2017-02-01

The aim of this study was to evaluate the physicochemical, morphological, crystallinity, thermal, and pasting properties of starches isolated from rice grains with brown, black, and red pericarp. Starch was isolated from the rice grains at initial storage time, and after 6months of storage at different storage temperatures (16, 24, 32 and 40°C). Starch isolated from the grains stored for 6months at 40°C showed darker coloration, surface deformation of granules, and a significant reduction in the extraction yield, final viscosity, enthalpy, and crystallinity, independent of the grain pericarp coloration. The time and storage temperature not influence the swelling power and solubility of starch isolated from grains with brown pericarp, while for the grains with black and red pericarp there was reduction in swelling power and solubility of starches isolated of grains stored at 40°C. Grains stored at 16°C showed minimum changes in starch properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reducing Postharvest Losses during Storage of Grain Crops to Strengthen Food Security in Developing Countries.

Science.gov (United States)

Kumar, Deepak; Kalita, Prasanta

2017-01-15

While fulfilling the food demand of an increasing population remains a major global concern, more than one-third of food is lost or wasted in postharvest operations. Reducing the postharvest losses, especially in developing countries, could be a sustainable solution to increase food availability, reduce pressure on natural resources, eliminate hunger and improve farmers' livelihoods. Cereal grains are the basis of staple food in most of the developing nations, and account for the maximum postharvest losses on a calorific basis among all agricultural commodities. As much as 50%-60% cereal grains can be lost during the storage stage due only to the lack of technical inefficiency. Use of scientific storage methods can reduce these losses to as low as 1%-2%. This paper provides a comprehensive literature review of the grain postharvest losses in developing countries, the status and causes of storage losses and discusses the technological interventions to reduce these losses. The basics of hermetic storage, various technology options, and their effectiveness on several crops in different localities are discussed in detail.

Reducing Postharvest Losses during Storage of Grain Crops to Strengthen Food Security in Developing Countries

Directory of Open Access Journals (Sweden)

Deepak Kumar

2017-01-01

Full Text Available While fulfilling the food demand of an increasing population remains a major global concern, more than one-third of food is lost or wasted in postharvest operations. Reducing the postharvest losses, especially in developing countries, could be a sustainable solution to increase food availability, reduce pressure on natural resources, eliminate hunger and improve farmers’ livelihoods. Cereal grains are the basis of staple food in most of the developing nations, and account for the maximum postharvest losses on a calorific basis among all agricultural commodities. As much as 50%–60% cereal grains can be lost during the storage stage due only to the lack of technical inefficiency. Use of scientific storage methods can reduce these losses to as low as 1%–2%. This paper provides a comprehensive literature review of the grain postharvest losses in developing countries, the status and causes of storage losses and discusses the technological interventions to reduce these losses. The basics of hermetic storage, various technology options, and their effectiveness on several crops in different localities are discussed in detail.

Pit Viper strikes at the Hanford site. Pit maintenance using robotics at the Hanford Tank Farms

International Nuclear Information System (INIS)

Roeder-Smith, Lynne

2002-01-01

The Pit Viper--a remote operations waste retrieval system--was developed to replace manual operations in the valve pits of waste storage tanks at the Hanford Site. The system consists of a typical industrial backhoe fitted with a robotic manipulator arm and is operated remotely from a control trailer located outside of the tank farm. Cameras mounted to the arm and within the containment tent allow the operator to view the entire pit area and operate the system using a joystick. The arm's gripper can grasp a variety of tools that allow personnel to perform cleaning, debris removal, and concrete repair tasks--a more efficient and less dose-intensive process than the previous 'long-pole' method. The project team overcame a variety of obstacles during development and testing of the Pit Viper system, and deployment occurred in Hanford Tank C-104 in December 2001

Increasing Sucrose Uptake Capacity of Wheat Grains Stimulates Storage Protein Synthesis1[W

Science.gov (United States)

Weichert, Nicola; Saalbach, Isolde; Weichert, Heiko; Kohl, Stefan; Erban, Alexander; Kopka, Joachim; Hause, Bettina; Varshney, Alok; Sreenivasulu, Nese; Strickert, Marc; Kumlehn, Jochen; Weschke, Winfriede; Weber, Hans

2010-01-01

Increasing grain sink strength by improving assimilate uptake capacity could be a promising approach toward getting higher yield. The barley (Hordeum vulgare) sucrose transporter HvSUT1 (SUT) was expressed under control of the endosperm-specific Hordein B1 promoter (HO). Compared with the wild type, transgenic HOSUT grains take up more sucrose (Suc) in vitro, showing that the transgene is functional. Grain Suc levels are not altered, indicating that Suc fluxes are influenced rather than steady-state levels. HOSUT grains have increased percentages of total nitrogen and prolamins, which is reflected in increased levels of phenylalanine, tyrosine, tryptophan, isoleucine, and leucine at late grain development. Transcript profiling indicates specific stimulation of prolamin gene expression at the onset of storage phase. Changes in gene expression and metabolite levels related to carbon metabolism and amino acid biosynthesis suggest deregulated carbon-nitrogen balance, which together indicate carbon sufficiency and relative depletion of nitrogen. Genes, deregulated together with prolamin genes, might represent candidates, which respond positively to assimilate supply and are related to sugar-starch metabolism, cytokinin and brassinosteroid functions, cell proliferation, and sugar/abscisic acid signaling. Genes showing inverse expression patterns represent potential negative regulators. It is concluded that HvSUT1 overexpression increases grain protein content but also deregulates the metabolic status of wheat (Triticum aestivum) grains, accompanied by up-regulated gene expression of positive and negative regulators related to sugar signaling and assimilate supply. In HOSUT grains, alternating stimulation of positive and negative regulators causes oscillatory patterns of gene expression and highlights the capacity and great flexibility to adjust wheat grain storage metabolism in response to metabolic alterations. PMID:20018590

Assessment and remediation of earthen pits in Alberta

International Nuclear Information System (INIS)

Lye, D.E.; Deibert, L.

1999-01-01

The proper decommissioning of abandoned earthen pits and the elimination of the associated environmental liabilities were discussed. An earthen pit is an excavated pit used by upstream oil and gas companies to contain/store/burn produced fluids and gases from either gas or oil producing operations. Produced fluids may include liquid hydrocarbons, process chemicals and water originating from oil wells, gas wells, and associated batteries and processing facilities. Improper operation and management at some pits has resulted in soil and/or groundwater contamination. In response to regulatory direction, petroleum operators in Alberta have begun the process of replacing earthen pits with alternative flaring and liquid storage facilities, and embarked on programs to assess, remediate and decommission earthen pits at their operations. This paper describes some of the challenges facing petroleum operators in this regard. It also outlines the regulatory framework within which decommissioning projects must be completed. 2 tabs

Mortality of insects and quality of maize grains in hermetic and non-hermetic storage

Directory of Open Access Journals (Sweden)

Priscila C. Viebrantz

2016-05-01

Full Text Available ABSTRACT Due to the need to improve the quality and safety of foods, chemical methods used to control grain pests have been replaced by alternative methods. For example, modified atmosphere within the storage units has been used. Therefore, the objective was to evaluate maize grain quality and mortality of insects of the species Sitophilus zeamais and Tribolium castaneum in hermetic and non-hermetic environments for 50 days of storage. The hermetic units consisted of polyethylene "bags" with capacity for 60 kg. A cage with 20 adults of each species and 200 g of maize was placed inside each unit. The oxygen level was quantified every five days. Evaluations of insect mortality and survival occurred at 10, 20, 30, 40 and 50 days of storage. At 0, 30 and 50 days, density, moisture and fungal incidence analyses were conducted. The airtight system is efficient in the control of insects, with satisfactory mortality values for both species. Insects favor the development of fungi during the storage, regardless of the storage system.

Evaluation of water chemistry on the pitting susceptibility of aluminum

International Nuclear Information System (INIS)

Chandler, G.T.; Sindelar, R.L.; Lam, P.S.

1997-01-01

Aluminum-clad spent nuclear fuels are being stored in water in the Receiving Basin for Off-site Fuels (RBOF) and the reactor disassembly (cooling) basins at the Savannah River Site (SRS). Experience shows that fuels stored in water are subject to rapid pitting corrosion if the water quality is poor. Upgrade projects and actions, including those to improve water quality, were recently undertaken to upgrade the disassembly basins for extended storage. A technical strategy was developed for continued basin storage of aluminum-clad fuel assemblies. The strategy includes development and implementation of basin technical standards for water quality to minimize attack due to pitting corrosion over a desired storage period. In the absence of localized corrosion, only slow, general corrosion of the cladding would be expected. A laboratory corrosion program is being performed to provide the bases for technical standards by identifying the region of aggressive water qualities where existing oxide films would tend to break down and pits would initiate and remain active. Initial results from corrosion potential and cyclic polarization testing of aluminum alloys in various water chemistries have shown that low conductivity water (< 50 μS/cm) should not be aggressive to cause self-pitting corrosion. Initial results from tests of 8001 and 5052 aluminum and aluminium-10% uranium alloy indicate that a strong galvanic couple should not exist between the aluminum cladding materials and the aluminum-uranium fuel. Additional laboratory testing will include immersion testing to allow characterization of the growth rate of active pits to benchmark a kinetic model. This model will form the basis for a water quality technical standard and enable prediction of the life of aluminum-clad spent nuclear fuels in basin storage

Low oxygen treatment prior to cold storage decreases the incidence of bitter pit in 'Golden Reinders' apples.

Science.gov (United States)

Val, Jesús; Fernández, Victoria; López, Paola; Peiró, Jose María; Blanco, Alvaro

2010-02-01

The effect of subjecting 'Golden Reinders' apples to a low O(2) pre-treatment (LOT; 1-2% O(2)) was evaluated as a strategy to decrease the rate of bitter pit (BP) incidence after standard cold storage (ST). Immediately after harvest, apples were stored for 10 days at 20 degrees C under low O(2). Thereafter, apples were cold-stored (0-4 degrees C) for 4 months and changes were monitored in terms of BP incidence, fruit quality traits and mineral element concentrations. After 4 months cold storage, LOT apples presented a 2.6-fold decrease in the rate of BP incidence (14%) versus the values obtained for standard cold-stored fruits (37% BP incidence). LOT increased flesh firmness, total soluble solids and titratable acidity as compared to the quality traits determined for cold-stored fruits. Lower cortex Ca and Mg concentrations as compared to ST apples were determined in association with LOT, 2 months after cold storage. Application of a LOT prior to cold storage may be a promising strategy to reduce the incidence of BP and preserve fruit quality, which should be further investigated.

Storage facility for radioactive wastes

International Nuclear Information System (INIS)

Okada, Kyo

1998-01-01

Canisters containing high level radioactive wastes are sealed in overpacks in a receiving building constructed on the ground. A plurality of storage pits are formed in a layered manner vertically in multi-stages in deep underground just beneath the receiving building, for example underground of about 1000m from the ground surface. Each of the storage pits is in communication with a shaft which vertically communicates the receiving building and the storage pits, and is extended plainly in a horizontal direction from the shaft. The storage pit comprises an overpack receiving chamber, a main gallery and a plurality of galleries. A plurality of holes for burying the overpacks are formed on the bottom of the galleries in the longitudinal direction of the galleries. A plurality of overpack-positioning devices which run in the main gallery and the galleries by remote operation are disposed in the main gallery and the galleries. (I.N.)

Pitting of 3003 aluminum

International Nuclear Information System (INIS)

Lee, R.

1996-01-01

The Advanced Photon Source is a state-of-the-art synchrotron light source. The storage ring vacuum chamber is fabricated from 6061 extruded Al. Water connections to the vacuum chambers that were fabricated from 3003 Al had developed water leaks, which were subsequently remedied after considerable investigations. Materials subjected to the pitting analysis in this study are 3003, 6061, and 6063 Al

Status of the pit disassembly and conversion facility

International Nuclear Information System (INIS)

Wood, Warren T.; Christensen, Lowell T.

2000-01-01

A planned new facility, the Pit Disassembly and Conversion Facility (PDCF), will be used to disassemble the nation's inventory of surplus nuclear weapons pits and convert the plutonium from those pits into a form suitable for storage, international inspection, and final disposition. Sized to handle 35 metric tons of plutonium from pits and other sources over its 10-year operating life, the PDCF will apply the Advanced Recovery and Integrated Extraction System (ARIES) technology. ARIES process technology has been developed at Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL), and an integrated system is being demonstrated at LANL. The Los Alamos National Laboratory is the lead for technical design oversight of the PDCF. Technical data gained from the ARIES demonstrations is integral for the proper design of the PDCF

Pitting morphologies of zirconium base alloys in aqueous and non aqueous chloride media

International Nuclear Information System (INIS)

Palit, G.C.; Gadiyar, H.S.

1988-01-01

Pitting morphology of zirconium and Zr-Cr alloys in aqueous chloride and nonaqueous methanol + 0.4 per cent HCl solution was investigated and observed to follow different modes in these two environments. While in aqueous chloride solution pitting was transgranular and randomly oriented, in methanol-chloride solution pits were observed to initiate and propagate along the grain boundaries. In aqueous chloride solution very irregular and sponge like zirconium metal was formed inside the pit while in methanol-chloride solution the pits were crystallographic in nature. Optical microscopy has revealed that pits preferentially initiate and propagate along scratch line in aqueous chloride solution, but such was not the case in nonaqueous methanol-chloride solution. The nature and the mechanism operating in the catastropic failure of these materials are investigated. (author). 10 refs., 11 figs

A functional genomics approach to understand the control and regulation of storage protein biosynthesis in barley grain

DEFF Research Database (Denmark)

Vincze, É; Hansen, M; Bowra, S

2008-01-01

assembled in our laboratory. To identify coregulated genes, a distance matrix was constructed and we identified three clusters corresponding to the early, middle and late seed development. The gene expression pattern associated with the clusters was investigated using pathway specific analysis with specific......The aim of the study was to obtain an insight into amino acid and storage protein metabolism in the developing barley grain at the molecular level. Our strategy was to analyse the transcriptome of relevant pathways in developing grains of field grown barley using a grain specific microarray...... pathways in the barley grain. The study described here could provide a strong complement to existing knowledge assisting further  understanding of seed development and thereby provide a foundation for plant breeding towards storage protein with improved nutritional quality....

Storage facility for highly radioactive solid waste

International Nuclear Information System (INIS)

Kitano, Shozo

1996-01-01

A heat insulation plate is disposed at an intermediate portion between a ceiling wall of a storage chamber and an upper plate of a storage pit in parallel with them. A large number of highly radioactive solid wastes contained in canisters are contained in the storage pit. Cooling air is introduced from an air suction port, passes a channel on the upper side of the heat insulation plate formed by the ceiling of the storage chamber and the heat insulation plate, and flows from a flow channel on the side of the wall of the storage chamber to the lower portion of the storage pit. Afterheat is removed by the air flown from the lower portion to ventilation tubes at the outer side of container tubes. The air heated to a high temperature through the flow channel on the lower side of the heat insulation plate between the heat insulation plate and the upper plate of the storage pit, and is exhausted to an exhaustion port. Further, a portion of a heat insulation plate as a boundary between the cooling air and a high temperature air formed on the upper portion of the storage pit is formed as a heat transfer plate, so that the heat of the high temperature air is removed by the cooling air flowing the upper flow channel. This can prevent heating of the ceiling wall of the storage chamber. (I.N.)

Gamma-radiation control of the Sitophilus-orizae insect pest in the wheat grain storage

International Nuclear Information System (INIS)

Ritacco, M.

1988-01-01

Insects produce very important grain lost in the cereal storage. This lost is highly variable according to the type of cereal and the stored time. The principal pest among coleopters is Sitophilus orizae which attacks wheat grains. Ionizing radiation allowed us to develope an alternative control method to the chemical insecticides which have serious disadvantages. Our results expressed as the DL 50 , showed a considerable reduction of adult life spanning from 250 Gy. Post-irradiation adquired sterility was observed in the stored grain due to the absence of descendents. (Autor) [es

Canister Storage Building Receiving Pit Modification Informal Design Verification

International Nuclear Information System (INIS)

KRIEG, S.A.

2000-01-01

The design for modifications to the CSB Cask Receiving pit guides was verified by the informal design verification (meeting) method on August 9, 2000. The invited list of attendees and the meeting attendance sheet are included in attachment 1. The design modifications that were reviewed are documented in ECN 654484 (attachment 2). The requirement that the design is to be verified against is to ''center the transportation cask sufficiently to allow installation of the guide funnel on the cask (± 0.25 inches or less)''. The alternatives considered are detailed in attachment 3. Alternative number 4, ''Modify The Pit Guides'', was determined to be the preferred alternative primarily due to considerations of simplicity, reliability, and low cost. Alternative 1, ''Rotate the impact Absorber 180 o '', was successfully performed but was considered a temporary fix that was not acceptable for a long term operational mode. The requirement to position the receiving crane accurately enough to lower the transportation cask into the pit with the redesigned guides was discussed and considered to be achievable without undue effort from the operator. The tolerance on the OD of the transfer cask was discussed (± 1/8 inch) relative to the clearance with the guides. As-built dimensions for the cask OD will be looked at to verify sufficient clearance exists with the maximum cask OD. The final design thickness of the shims under the guides will be based on the as-built cask OD dimensions and field measurements between the pit guides. The need for a ''plastic'' cover for the guides was discussed and deemed unnecessary. Thermal growth of the cask OD was calculated at 3-5 mils and considered insignificant. The possibility of reducing the OD of the guide funnel was reviewed but this was considered impractical due to the requirement for the MCO to miss the edge of the funnel in case of a MCO drop. One of the transportation casks have the lift trunions installed 3/8 inch off center. This is

Performance of triple bagging hermetic technology for postharvest storage of cowpea grain in Niger

KAUST Repository

Baoua, Ibrahim B.

2012-10-01

Triple bagging technology for protecting postharvest cowpea grain from losses to the bruchid, Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae: Bruchinae) is currently being adopted on a fairly large scale in ten West and Central African countries, including Niger. The triple bag consists of two inner high-density polyethylene bags acting as oxygen barriers, which in turn are encased in an outer woven polypropylene bag that serves primarily for mechanical strength. These hermetic bags, available in either 50 or 100 kg capacity, are called Purdue Improved Cowpea Storage (PICS) bags. Adoption of PICS technology in West and Central Africa has been driven by its effectiveness, simplicity, low cost, durability, and manufacture within the region. From surveys on adoption we discovered that farmers have begun to re-use bags they had used the previous year or even the previous two years. In the present study, we compared the performance of three different types of PICS bags: (1) new 50 kg (2) new 100 kg bags and (3) once-used 50 kg bags, all filled with naturally infested untreated cowpeas. In these PICS bags the O 2 levels within the bags initially fell to about 3 percent (v/v) while the CO 2 rose to nearly 5 percent (v/v). After five months of storage, new and used 50 kg bags and new 100 kg bags preserved the grain equally well. There were greatly reduced numbers of adults and larvae in the PICS bags versus the controls, which consisted of grain stored in single layer woven bags. The proportion of grain having C. maculatus emergence holes after five months of storage in PICS bags was little changed from that found when the grain was first put into the bags. The PICS technology is practical and useful in Sahelian conditions and can contribute to improved farmers\\' incomes as well as increase availability of high quality, insecticide-free cowpea grain as food. © 2012 Elsevier Ltd.

Kefir Grains Change Fatty Acid Profile of Milk during Fermentation and Storage

Science.gov (United States)

Vieira, C. P.; Álvares, T. S.; Gomes, L. S.; Torres, A. G.; Paschoalin, V. M. F.; Conte-Junior, C. A.

2015-01-01

Several studies have reported that lactic acid bacteria may increase the production of free fatty acids by lipolysis of milk fat, though no studies have been found in the literature showing the effect of kefir grains on the composition of fatty acids in milk. In this study the influence of kefir grains from different origins [Rio de Janeiro (AR), Viçosa (AV) e Lavras (AD)], different time of storage, and different fat content on the fatty acid content of cow milk after fermentation was investigated. Fatty acid composition was determined by gas chromatography. Values were considered significantly different when pkefir relatively to fermented kefir leading to possible increase of antimutagenic and anticarcinogenic potential and improvement of nutritional quality of lipids in storage milk. Only high-lipidic matrix displayed increase polyunsaturated fatty acids after fermentation. These findings open up new areas of study related to optimizing desaturase activity during fermentation in order to obtaining a fermented product with higher nutritional lipid quality. PMID:26444286

Corrective Action Investigation Plan for Corrective Action Unit 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site, Nevada, July 2002, Rev. No. 0

International Nuclear Information System (INIS)

2002-01-01

This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 140 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 140 consists of nine Corrective Action Sites (CASs): 05-08-01, Detonation Pits; 05-08-02, Debris Pits; 05-17-01, Hazardous Waste Accumulation Site (Buried); 05-19-01, Waste Disposal Site; 05-23-01, Gravel Gertie; 05-35-01, Burn Pit; 05-99-04, Burn Pit; 22-99-04, Radioactive Waste Dump; 23-17-01, Hazardous Waste Storage Area. All nine of these CASs are located within Areas 5, 22, and 23 of the Nevada Test Site (NTS) in Nevada, approximately 65 miles northwest of Las Vegas. This CAU is being investigated because disposed waste may be present without appropriate controls (i.e., use restrictions, adequate cover) and hazardous and/or radioactive constituents may be present or migrating at concentrations and locations that could potentially pose a threat to human health and the environment. The NTS has been used for various research and development projects including nuclear weapons testing. The CASs in CAU 140 were used for testing, material storage, waste storage, and waste disposal. A two-phase approach has been selected to collect information and generate data to satisfy needed resolution criteria and resolve the decision statements. Phase I will determine if contaminants of potential concern (COPCs) are present in concentrations exceeding preliminary action levels. This data will be evaluated at all CASs. Phase II will determine the extent of the contaminant(s) of concern (COCs). This data will only be evaluated for CASs with a COC identified during Phase I. Based on process knowledge, the COPCs for CAU 140 include volatile organics, semivolatile organics, petroleum hydrocarbons, explosive residues

Spent fuel element storage facility

International Nuclear Information System (INIS)

Ukaji, Hideo; Yamashita, Rikuo.

1981-01-01

Purpose: To always keep water level of a spent fuel cask pit equal with water level of spent fuel storage pool by means of syphon principle. Constitution: The pool water of a spent fuel storage pool is airtightly communicated through a pipe with the pool water of a spent fuel cask, and a gate is provided between the pool and the cask. Since cask is conveyed into the cask pit as the gate close while conveying, the pool water level is raised an amount corresponding to the volume of the cask, and water flow through scattering pipe and the communication pipe to the storage pool. When the fuel is conveyed out of the cask, the water level is lowered in the amount corresponding to the volume in the cask pit, and the water in the pool flow through the communication pipe to the cask pit. (Sekiya, K.)

Corrective action plan for corrective action Unit 342: Area 23 Mercury Fire Training Pit, Nevada Test Site, Nevada

International Nuclear Information System (INIS)

Nacht, S.

1999-01-01

The Mercury Fire Training Pit is a former fire training area located in Area 23 of the Nevada Test Site (NTS). The Mercury Fire Training Pit was used from approximately 1965 to the early 1990s to train fire-fighting personnel at the NTS, and encompasses an area approximately 107 meters (m) (350 feet [ft]) by 137 m (450 ft). The Mercury Fire Training Pit formerly included a bermed burn pit with four small burn tanks, four large above ground storage tanks an overturned bus, a telephone pole storage area, and areas for burning sheds, pallets, and cables. Closure activities will include excavation of the impacted soil in the aboveground storage tank and burn pit areas to a depth of 1.5 m (5 ft), and excavation of the impacted surface soil downgradient of the former ASTs and burnpit areas to a depth of 0.3 m (1 ft). Excavated soil will be disposed in the Area 6 Hydrocarbon Landfill at the NTS

Copper Tube Pitting in Santa Fe Municipal Water Caused by Microbial Induced Corrosion.

Science.gov (United States)

Burleigh, Thomas D; Gierke, Casey G; Fredj, Narjes; Boston, Penelope J

2014-06-05

Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC). In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS), then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM). The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water.

Copper Tube Pitting in Santa Fe Municipal Water Caused by Microbial Induced Corrosion

Directory of Open Access Journals (Sweden)

Thomas D. Burleigh

2014-06-01

Full Text Available Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC. In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS, then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM. The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water.

INFLUENCE OF TEMPERATURE AND RELATIVE HUMIDITY ON GRAIN MOISTURE, GERMINATION AND VIGOUR OF THREE WHEAT CULTIVARS DURING ONE YEAR STORAGE

Directory of Open Access Journals (Sweden)

Ivica Strelec

2010-12-01

Full Text Available Changes in grain moisture, germination and vigour of three wheat cultivars packed in paper bags and stored for one year under four different conditions of environmental temperature and relative humidity (RH were investigated. During the first ninety days of storage significant reduction in grain moisture content of 4, 2.5 and 0.9 %, respectively, under 40 °C, 25 °C and 4 °C and RH of 45 % occurred. Subsequently grain moisture remained constant until the end of storage. Seeds of examined cultivars lost their germination ability and vigour only under elevated storage temperatures. Germination and vigour loss after one year of storage differed between cultivars being higher for seeds kept under 40°C, RH = 45% (35-85 % and 55-94 %, respectively, than under 25°C, RH = 45 % (10-20 % and 15-22 %, respectively. Obtained data indicate significant influence of storage conditions on moisture content, germination and vigour changes during storage of wheat seeds, as well as varietal dependence of seed viability.

Physiological behavior of bean's seeds and grains during storage

Directory of Open Access Journals (Sweden)

FLÁVIA D.R. CASSOL

2016-06-01

Full Text Available Beans are one of the most used foods to meet the energy needs of the Brazilian diet, requiring farmers to use high seed physiological potential. The aim was to evaluate the physiological quality of beans stored for 360 days. Analyses were performed at 0, 30, 90, 180, 270, and 360 days after receiving the seeds (S1 and S2 and grains (G1 and G2 of BRS Splendor. Tests of germination, accelerated aging, cold, speed of germination, average length of shoots, and root were performed. The experimental design was completely randomized split-plot in time and the means were compared through Tukey test at 5% probability. Seed germination was not affected in S2, while the drop in S1 and G1 was significant. The vigor of grains from field 1 declined from 91 to 50% and from 93% to 76% by accelerated aging and cold, respectively, after 360 days. The germination speed tests performed showed a decreased during the experiment. The grains from field 1 had lower physiological quality. The accelerated aging and cold tests, through the speed of germination parameter, showed decrease in the vigor of the Splendor BRS. The storage period influenced the physiological quality of the beans tested.

Physiological behavior of bean's seeds and grains during storage.

Science.gov (United States)

Cassol, Flávia D R; Fortes, Andréa M T; Mendonça, Lorena C; Buturi, Camila V; Marcon, Thaís R

2016-05-31

Beans are one of the most used foods to meet the energy needs of the Brazilian diet, requiring farmers to use high seed physiological potential. The aim was to evaluate the physiological quality of beans stored for 360 days. Analyses were performed at 0, 30, 90, 180, 270, and 360 days after receiving the seeds (S1 and S2) and grains (G1 and G2) of BRS Splendor. Tests of germination, accelerated aging, cold, speed of germination, average length of shoots, and root were performed. The experimental design was completely randomized split-plot in time and the means were compared through Tukey test at 5% probability. Seed germination was not affected in S2, while the drop in S1 and G1 was significant. The vigor of grains from field 1 declined from 91 to 50% and from 93% to 76% by accelerated aging and cold, respectively, after 360 days. The germination speed tests performed showed a decreased during the experiment. The grains from field 1 had lower physiological quality. The accelerated aging and cold tests, through the speed of germination parameter, showed decrease in the vigor of the Splendor BRS. The storage period influenced the physiological quality of the beans tested.

Using RFID and PIT tags to Quantify Bedload Transport in the Oregon Coast Range

Science.gov (United States)

Sanfilippo, J.; Lancaster, S. T.

2017-12-01

Introducing the methods, issues, and data collection techniques and interpretation over one water year using RFID (radio frequency identification) and PIT (passive integrated transponder) tags in Oak Creek, near Corvallis Oregon. We constructed an RFID four-antenna array that runs off of a single radiofrequency reader via a multiplexer board. Using 4 grain sizes we tagged 990 individual rocks, roughly 250 in of each four size ranges (8-16mm, 16-32mm, 32-64mm, 64-128mm). Using 12 mm and 23 mm PIT tags during 1 water year the antennas logged 477 tracer passage events. To calculate bedload transport for each size range, at each antenna, interarrival times yield count rates when combined with grain size fractions of the bed and tracer concentrations, yield bedload transport for each size class. We calculated transport rates for five events of varying magnitude and found that PIT tag RFID method under predicts transport between 1 and 3 orders of magnitude.

Kefir Grains Change Fatty Acid Profile of Milk during Fermentation and Storage.

Science.gov (United States)

Vieira, C P; Álvares, T S; Gomes, L S; Torres, A G; Paschoalin, V M F; Conte-Junior, C A

2015-01-01

Several studies have reported that lactic acid bacteria may increase the production of free fatty acids by lipolysis of milk fat, though no studies have been found in the literature showing the effect of kefir grains on the composition of fatty acids in milk. In this study the influence of kefir grains from different origins [Rio de Janeiro (AR), Viçosa (AV) e Lavras (AD)], different time of storage, and different fat content on the fatty acid content of cow milk after fermentation was investigated. Fatty acid composition was determined by gas chromatography. Values were considered significantly different when p<0.05. The highest palmitic acid content, which is antimutagenic compost, was seen in AV grain (36.6g/100g fatty acids), which may have contributed to increasing the antimutagenic potential in fermented milk. Higher monounsaturated fatty acid (25.8 g/100g fatty acids) and lower saturated fatty acid (72.7 g/100g fatty acids) contents were observed in AV, when compared to other grains, due to higher Δ9-desaturase activity (0.31) that improves the nutritional quality of lipids. Higher oleic acid (25.0 g/100g fatty acids) and monounsaturated fatty acid (28.2g/100g fatty acids) and lower saturated fatty acid (67.2g/100g fatty acids) contents were found in stored kefir relatively to fermented kefir leading to possible increase of antimutagenic and anticarcinogenic potential and improvement of nutritional quality of lipids in storage milk. Only high-lipidic matrix displayed increase polyunsaturated fatty acids after fermentation. These findings open up new areas of study related to optimizing desaturase activity during fermentation in order to obtaining a fermented product with higher nutritional lipid quality.

Microstructure and pitting corrosion of shielded metal arc welded high nitrogen stainless steel

Directory of Open Access Journals (Sweden)

Raffi Mohammed

2015-09-01

Full Text Available The present work is aimed at studying the microstructure and pitting corrosion behaviour of shielded metal arc welded high nitrogen steel made of Cromang-N electrode. Basis for selecting this electrode is to increase the solubility of nitrogen in weld metal due to high chromium and manganese content. Microscopic studies were carried out using optical microscopy (OM and field emission scanning electron microscopy (FESEM. Energy back scattered diffraction (EBSD method was used to determine the phase analysis, grain size and orientation image mapping. Potentio-dynamic polarization testing was carried out to study the pitting corrosion resistance in aerated 3.5% NaCl environment using a GillAC electrochemical system. The investigation results showed that the selected Cr–Mn–N type electrode resulted in a maximum reduction in delta-ferrite and improvement in pitting corrosion resistance of the weld zone was attributed to the coarse austenite grains owing to the reduction in active sites of the austenite/delta ferrite interface and the decrease in galvanic interaction between austenite and delta-ferrite.

Impacts of swine manure pits on groundwater quality

International Nuclear Information System (INIS)

Krapac, I.G.; Dey, W.S.; Roy, W.R.; Smyth, C.A.; Storment, E.; Sargent, S.L.; Steele, J.D.

2002-01-01

New information is presented on impacts on groundwater by manure storage in deep ground pits. - Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and δ 15 N and δ 18 O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human health. Fecal

Impacts of swine manure pits on groundwater quality

Energy Technology Data Exchange (ETDEWEB)

Krapac, I.G.; Dey, W.S.; Roy, W.R.; Smyth, C.A.; Storment, E.; Sargent, S.L.; Steele, J.D

2002-12-01

New information is presented on impacts on groundwater by manure storage in deep ground pits. - Manure deep-pits are commonly used to store manure at confined animal feeding operations. However, previous to this study little information had been collected on the impacts of deep-pits on groundwater quality to provide science-based guidance in formulating regulations and waste management strategies that address risks to human health and the environment. Groundwater quality has been monitored since January 1999 at two hog finishing facilities in Illinois that use deep-pit systems for manure storage. Groundwater samples were collected on a monthly basis and analyzed for inorganic and bacteriological constituent concentrations. The two sites are located in areas with geologic environments representing different vulnerabilities for local groundwater contamination. One site is underlain by more than 6 m of clayey silt, and 7-36 m of shale. Concentrations of chloride, ammonium, phosphate, and potassium indicated that local groundwater quality had not been significantly impacted by pit leakage from this facility. Nitrate concentrations were elevated near the pit, often exceeding the 10 mg N/l drinking water standard. Isotopic nitrate signatures suggested that the nitrate was likely derived from soil organic matter and fertilizer applied to adjacent crop fields. At the other site, sandstone is located 4.6-6.1 m below land surface. Chloride concentrations and {delta}{sup 15}N and {delta}{sup 18}O values of dissolved nitrate indicated that this facility may have limited and localized impacts on groundwater. Other constituents, including ammonia, potassium, phosphate, and sodium were generally at or less than background concentrations. Trace- and heavy-metal concentrations in groundwater samples collected from both facilities were at concentrations less than drinking water standards. The concentration of inorganic constituents in the groundwater would not likely impact human

Effect of heat treatment on pitting corrosion of austenitic Cr-Ni-Mo steels in sodium chloride solution

International Nuclear Information System (INIS)

Stefec, R.; Franz, F.; Holecek, A.

1979-01-01

The pitting corrosion resistance of Cr17Ni12Mo2,5 type steel under potentiostatic polarization in a sodium chloride solution is adversely affected by previous annealing. The data obtained were systematically dependent on annealing temperature, time and surface roughness. The corrosion current, the number of pits or the mean area of pit opening and the corrosion rate within the pits were increased by previous annealing at 550 to 750 0 C for 1-100 hrs. The highest corrosion rate estimated corresponded to heat treatments provoking severe sensitization to intergranular corrosion. The paercentage area of corrosion pit openings and the estimated pit penetration rates were several times higher for as-machined than for polished surfaces. It can be assumed that pitting corrosion is little affected by the carbon content and that molybdenum depletion of grain-boundary zones is responsible for the reduced pitting resistance of annealed steels. (orig./HP) [de

Effects of heat input on the pitting resistance of Inconel 625 welds by overlay welding

Science.gov (United States)

Kim, Jun Seok; Park, Young IL; Lee, Hae Woo

2015-03-01

The objective of this study was to establish the relationship between the dilution ratio of the weld zone and pitting resistance depending on the heat input to welding of the Inconel alloy. Each specimen was produced by electroslag welding using Inconel 625 as the filler metal. In the weld zone of each specimen, dendrite grains were observed near the fusion line and equiaxed grains were observed on the surface. It was also observed that a melted zone with a high Fe content was formed around the fusion line, which became wider as the welding heat input increased. In order to evaluate the pitting resistance, potentiodynamic polarization tests and CPT tests were conducted. The results of these tests confirmed that there is no difference between the pitting resistances of each specimen, as the structures of the surfaces were identical despite the effect of the differences in the welding heat input for each specimen and the minor dilution effect on the surface.

Phase II Investigation at the Former CCC/USDA Grain Storage Facility in Savannah, Missouri

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, Lorraine M. [Argonne National Lab. (ANL), Argonne, IL (United States). Environmental Science Division. Applied Geosciences and Environmental Management Section

2012-05-01

From approximately 1949 until 1970, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility on federally owned property approximately 0.25 mi northwest of Savannah, Missouri. During this time, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the private grain storage industry to preserve grain in their facilities. In November 1998, carbon tetrachloride was detected in a private well (Morgan) roughly 50 ft south of the former CCC/USDA facility, as a result of statewide screening of private wells near former CCC/USDA facilities, conducted in Missouri by the U.S. Environmental Protection Agency (EPA 1999). The 1998 and subsequent investigations by the EPA and the Missouri Department of Natural Resources (MDNR) confirmed the presence of carbon tetrachloride in the Morgan well, as well as in a second well on property currently owned by the Missouri Department of Transportation (MoDOT), directly east of the former CCC/USDA facility. The identified concentrations in these two wells were above the EPA maximum contaminant level (MCL) and the Missouri risk-based corrective action default target level (DTL) values of 5.0 μg/L for carbon tetrachloride in water used for domestic purposes (EPA 1999; MDNR 2000a,b, 2006). Because the observed contamination in the Morgan and MoDOT wells might be linked to the past use of carbon tetrachloride-based fumigants at its former grain storage facility, the CCC/USDA is conducting an investigation to (1) characterize the source(s), extent, and factors controlling the subsurface distribution and movement of carbon tetrachloride and (2) evaluate the potential risks to human health, public welfare, and the environment posed by the contamination. This work is being performed in accord with an Intergovernmental Agreement established in 2007 between the Farm Service Agency of the USDA and the MDNR, to address carbon tetrachloride

Corrosion Resistance and Pitting Behaviour of Low-Carbon High-Mn Steels in Chloride Solution

Directory of Open Access Journals (Sweden)

Grajcar A.

2016-06-01

Full Text Available Corrosion resistance of the X4MnSiAlNbTi27-4-2 and X6MnSiAlNbTi26-3-3 type austenitic steels, after hot deformation as well as after cold rolling, were evaluated in 3.5% NaCl solution using potentiodynamic polarization tests. A type of nonmetallic inclusions and their pitting corrosion behaviour were investigated. Additionally, the effect of cold deformation on the corrosion resistance of high-Mn steels was studied. The SEM micrographs revealed that corrosion damage formed in both investigated steels is characterized by various shapes and an irregular distribution at the metallic matrix, independently on the steel state (thermomechanically treated or cold worked. Corrosion pits are generated both in grain interiors, grain boundaries and along the deformation bands. Moreover, corrosion damage is stronger in cold deformed steels in comparison to the thermomechanically treated specimens. EDS analysis revealed that corrosion pits preferentially nucleated on MnS and AlN inclusions or complex oxysulphides. The morphology of corrosion damage in 3.5% NaCl supports the data registered in potentiodynamic tests.

[The relationship between activity and gene expression of phenylalanine ammonia-lyase and peel pitting in 'Fengjie' navel orange fruits].

Science.gov (United States)

Li, Zheng-Guo; Gao, Xue; Fan, Jing; Yang, Ying-Wu; Li, Dao-Gao; Kanellis, Angelos K

2006-06-01

Citrus fruit is prone to develop peel pitting during development and storage, which greatly decreases its fresh market value because of the deterioration of the peel. In the present study, we have examined the effect of different temperatures (15 degrees C and 4 degrees C), waxing and mechanical damage on the changes in the activity of phenylalanine ammonia-lyase (PAL) and the incidence of peel pitting in 'Fengjie' navel orange (Citrus sinensis Osbeck) fruits. The expression levels of PAL2, PAL6 genes in the peel during the development of peel pitting have been investigated through semi-quantitative PCR method. The incidence of peel pitting was greatly enhanced by waxing and mechanical damage and was decreased in lower temperature storage (4 degrees C) (Fig.1). Waxing and mechanical damage might be the important factors inducing peel pitting and suitable low temperature could decrease the incidence of this disease. The PAL activity increased during the whole storage period in accordance with the development of this pitting (Fig.2). The expression levels of PAL2 and PAL6 genes in damaged peel were higher than those in healthy peel and the expression of PAL2 is much more higher than that of PAL6 (Figs.4 and 5). The results suggested that the enzyme activity of PAL, along with the expression of PAL2 gene is highly related to this peel pitting occurred on 'Fengjie' navel orange fruits.

Gamma radiation in the control of important storage pests of three grain legumes

International Nuclear Information System (INIS)

Roy, M.K.; Prasad, H.H.

1993-01-01

A dose of 1 kGy of gamma radiation completely killed adult pulse beetle (Callosobruchus chinensis Linn) within a week, but the dose of 0.5 kGy required two weeks to achieve the same level of mortality. For six month storage, 1.0 kGy dose was effective for control of natural infestation of mung beans and gram by C. Chinensis alone. The dose was also sufficient for the management of weevilling in gram and lentil, which were additionally infested with C. chinensis, rust red flour beetle (Tribolium castaneum Herbst), and lesser grain borer (Rhizopertha dominica Fabricius). For short (one and half months) storage of mung bean and lentil, a dose of 0.25 kGy was adequate. The test of significance for doses of radiation, storage periods and their interactions, however, indicated that 1.0 kGy is the preferred dose for the control of weevilling during storage upto 6 months. (author). 13 refs., 4 tabs

Why do Pit-Hours outlive the Pit?

NARCIS (Netherlands)

S.R. Ozturk (Sait); M. van der Wel (Michel); D.J.C. van Dijk (Dick)

2015-01-01

markdownabstract__Abstract__ We study why a majority of trades still happen during the pit hours, i.e. when the trading pit is open, even after the pit ceased to be a liquid and informative venue. We investigate the case of 30-year U.S. Treasury futures using a ten-years-long intraday data set

Optic Nerve Pit

Science.gov (United States)

... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Optic Nerve Pit What is optic nerve pit? An optic nerve pit is a ... may be seen in both eyes. How is optic pit diagnosed? If the pit is not affecting ...

Significance of grain boundaries and stacking faults on hydrogen storage properties of Mg2Ni intermetallics processed by high-pressure torsion

International Nuclear Information System (INIS)

Hongo, Toshifumi; Edalati, Kaveh; Arita, Makoto; Matsuda, Junko; Akiba, Etsuo; Horita, Zenji

2015-01-01

Mg 2 Ni intermetallics are processed using three different routes to produce three different microstructural features: annealing at high temperature for coarse grain formation, severe plastic deformation through high-pressure torsion (HPT) for nanograin formation, and HPT processing followed by annealing for the introduction of stacking faults. It is found that both grain boundaries and stacking faults are significantly effective to activate the Mg 2 Ni intermetallics for hydrogen storage at 423 K (150 °C). The hydrogenation kinetics is also considerably enhanced by the introduction of large fractions of grain boundaries and stacking faults while the hydrogenation thermodynamics remains unchanged. This study shows that, similar to grain boundaries and cracks, stacking faults can act as quick pathways for the transportation of hydrogen in the hydrogen storage materials

Effect of Equal-Channel Angular Pressing on Pitting Corrosion of Pure Aluminum

Directory of Open Access Journals (Sweden)

Injoon Son

2012-01-01

Full Text Available The effect of equal-channel angular pressing (ECAP on the pitting corrosion of pure Al was investigated using electrochemical techniques in solutions containing 0.1 m mol·dm−3 of Na2SO4 and 8.46 mol·dm−3 of NaCl (300 ppm Cl− and followed by surface analysis. The potential for pitting corrosion of pure Al was clearly shifted in the noble direction by the ECAP process indicating that this process improves resistance to pitting corrosion. The time dependence of corrosion potential and the anodic potential at 1 A·m−2 revealed that the rate of formation of Al oxide films increased due to a decrease in the grain size of the Al after ECAP. Since there exists a negligible amount of impurity precipitates in pure Al, the improvement in pitting corrosion resistance of pure Al by ECAP appears to be attributable to an increase in the rate of formation of Al oxide films.

Development of pits and cones on ion bombarded copper

International Nuclear Information System (INIS)

Tanovic, L.A.; Carter, G.; Nobes, M.J.; Whitton, I.L.; Williams, J.S.

1980-01-01

The formation of pits and cones on Ar ion bombarded copper has been studied. Carefully polished surfaces of large grained 99.999% pure copper crystals have been bombarded at normal incidence with 40 keV argon ions. The cone formation has been investigated for annealed and non-annealed crystals at room temperature and at 30 K and in the case of monocrystal and polycrystal samples. Although in the most other studies the presence of impurities is as a necessary condition for generation of cones and pits the obtained experimental results show that under certain conditions these features are formed on clean surfaces. It is shown that the dominant parameter in the production of cones on copper is the crystal orientation [ru

Predição de "bitter pit" em maçãs 'gala' Por meio da infiltração dos frutos com magnésio Prediction of bitter pit in 'gala'apples by means of fruit infiltration with magnesium

Directory of Open Access Journals (Sweden)

Cassandro Vidal Talamini do Amarante

2009-12-01

o risco de ocorrência de "bitter pit" durante o armazenamento refrigerado em maçãs 'Gala' cultivadas no Sul do Brasil.Bitter pit is one of the main postharvest physiological disorders in apples. Fruit mineral analysis (concentrations of Ca, Mg, K, and N, normally used to assess bitter pit risk, is expensive and shows a low predictive potential. This has stimulated the development of alternative methods to predict at the preharvest period the postharvest risk of bitter pit occurrence. The objective of this work was to assess the feasibility of fruit infiltration with Magnesium (Mg to predict the risk of bitter pit occurrence during cold storage of 'Gala' apples. In addition, Ca concentrations (mg kg-1 of fresh weight in the flesh and skin tissues of the fruit with different levels of bitter pit severity and incidence, in both fruits, infiltrated with Mg or left in cold storage, were plotted to predict the risk of bitter pit in terms of Ca content. Fruits were harvested in an orchard with high incidence of bitter pit, in Lages, SC, in 2003/2004. Samples of fruits were harvested from 20 randomly marked trees, corresponding to 30 fruits for infiltration with Mg (harvested 20 days before the commercial maturity and 100 fruits for cold storage (harvested at the commercial maturity. The levels of Ca in the fruits above those which there were low risk of bitter pit were similar among fruits infiltrated with Mg and those left in cold storage, corresponding to 55 and 192 mg kg-1 for flesh and skin tissues, respectively. The Ca concentration quantified in the skin tissue provided a better prediction of bitter pit risk than when quantified in the flesh tissue. The results showed that fruit infiltration with Mg represents a feasible method to assess the bitter pit risk during cold storage in 'Gala' apples grown in Southern Brazil.

Statistical characterization of pitting corrosion process and life prediction

International Nuclear Information System (INIS)

Sheikh, A.K.; Younas, M.

1995-01-01

In order to prevent corrosion failures of machines and structures, it is desirable to know in advance when the corrosion damage will take place, and appropriate measures are needed to mitigate the damage. The corrosion predictions are needed both at development as well as operational stage of machines and structures. There are several forms of corrosion process through which varying degrees of damage can occur. Under certain conditions these corrosion processes at alone and in other set of conditions, several of these processes may occur simultaneously. For a certain type of machine elements and structures, such as gears, bearing, tubes, pipelines, containers, storage tanks etc., are particularly prone to pitting corrosion which is an insidious form of corrosion. The corrosion predictions are usually based on experimental results obtained from test coupons and/or field experiences of similar machines or parts of a structure. Considerable scatter is observed in corrosion processes. The probabilities nature and kinetics of pitting process makes in necessary to use statistical method to forecast the residual life of machine of structures. The focus of this paper is to characterization pitting as a time-dependent random process, and using this characterization the prediction of life to reach a critical level of pitting damage can be made. Using several data sets from literature on pitting corrosion, the extreme value modeling of pitting corrosion process, the evolution of the extreme value distribution in time, and their relationship to the reliability of machines and structure are explained. (author)

Variations in grain lipophilic phytochemicals, proteins and resistance to Fusarium spp. growth during grain storage as affected by biological plant protection with Aureobasidium pullulans (de Bary).

Science.gov (United States)

Wachowska, Urszula; Tańska, Małgorzata; Konopka, Iwona

2016-06-16

Modern agriculture relies on an integrated approach, where chemical treatment is reduced to a minimum and replaced by biological control that involves the use of active microorganisms. The effect of the antagonistic yeast-like fungus Aureobasidium pullulans on proteins and bioactive compounds (alkylresorcinols, sterols, tocols and carotenoids) in winter wheat grain and on the colonization of wheat kernels by fungal microbiota, mainly Fusarium spp. pathogens, was investigated. Biological treatment contributed to a slight increase contents of tocols, alkylresorcinols and sterols in grain. At the same time, the variation of wheat grain proteins was low and not significant. Application of A. pullulans enhanced the natural yeast colonization after six months of grain storage and inhibited growth of F. culmorum pathogens penetrating wheat kernel. This study demonstrated that an integrated approach of wheat grain protection with the use of the yeast-like fungus A. pullulans reduced kernel colonization by Fusarium spp. pathogens and increased the content of nutritionally beneficial phytochemicals in wheat grain without a loss of gluten proteins responsible for baking value. Copyright © 2016. Published by Elsevier B.V.

Cogema experience on retrieving and conditioning solid radwaste previously stored in pits. The La Hague north west pit case

International Nuclear Information System (INIS)

Bodin, F.; Alexandre, D.; Fournier, Ph.

2000-01-01

Short lived, low and medium level waste called 'technological waste' produced by the La Hague Reprocessing Plant have been stored in the La Hague North-West concrete-lined pits until implementation at ANDRA's Centre de Stockage de la Manche (CSM). COGEMA decided to retrieve and condition 11,000 m 3 of humid solid radwaste, stored in bulk in pits. This report describes the experience gained from February 1990 to December 1998, taking into account radwaste and integrated dose rate results conditioning such waste. The procedures and means used and improved by COGEMA to comply with ANDRA's storage standards and the ever-decreasing financial costs generated by the workers, allowed to retrieve and condition 11,000 m 3 of old solid radwaste with competitive costs and in complete safety and protection of the environment. (authors)

Bitter pit in apples: pre- and postharvest factors: A review

International Nuclear Information System (INIS)

Jemrić, T.; Fruk, I.; Fruk, M.; Radman, S.; Sinkovič, L.; Fruk, G.

2016-01-01

Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg), cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

Bitter pit in apples: pre- and postharvest factors: A review

Energy Technology Data Exchange (ETDEWEB)

Jemrić, T.; Fruk, I.; Fruk, M.; Radman, S.; Sinkovič, L.; Fruk, G.

2016-07-01

Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg), cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

Improving NIR snow pit stratigraphy observations by introducing a controlled NIR light source

Science.gov (United States)

Dean, J.; Marshall, H.; Rutter, N.; Karlson, A.

2013-12-01

Near-infrared (NIR) photography in a prepared snow pit measures mm-/grain-scale variations in snow structure, as reflectivity is strongly dependent on microstructure and grain size at the NIR wavelengths. We explore using a controlled NIR light source to maximize signal to noise ratio and provide uniform incident, diffuse light on the snow pit wall. NIR light fired from the flash is diffused across and reflected by an umbrella onto the snow pit; the lens filter transmits NIR light onto the spectrum-modified sensor of the DSLR camera. Lenses are designed to refract visible light properly, not NIR light, so there must be a correction applied for the subsequent NIR bright spot. To avoid interpolation and debayering algorithms automatically performed by programs like Adobe's Photoshop on the images, the raw data are analyzed directly in MATLAB. NIR image data show a doubling of the amount of light collected in the same time for flash over ambient lighting. Transitions across layer boundaries in the flash-lit image are detailed by higher camera intensity values than ambient-lit images. Curves plotted using median intensity at each depth, normalized to the average profile intensity, show a separation between flash- and ambient-lit images in the upper 10-15 cm; the ambient-lit image curve asymptotically approaches the level of the flash-lit image curve below 15cm. We hypothesize that the difference is caused by additional ambient light penetrating the upper 10-15 cm of the snowpack from above and transmitting through the wall of the snow pit. This indicates that combining NIR ambient and flash photography could be a powerful technique for studying penetration depth of radiation as a function of microstructure and grain size. The NIR flash images do not increase the relative contrast at layer boundaries; however, the flash more than doubles the amount of recorded light and controls layer noise as well as layer boundary transition noise.

Integrity assessment of a storage tank

Energy Technology Data Exchange (ETDEWEB)

Goncalves, Osorio Correa; Santos, Jose Henrique Gomes dos; Carvalho, Alexis Fernandes [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

2005-07-01

In the last internal inspection of a 5000 bbl freshwater storage tank located in a shipping terminal, widespread pitting corrosion was detected on the shell courses. In some of these pits, its depth was such that the remaining thickness was bellow the minimum thickness required according to the design code. Nevertheless, this approach is overly conservative since it does not consider the pits size, depth and spacing. Thanks to advances in stress analysis, new tools are available for the evaluation of damaged equipment widely employed in the oil industry such as pressure vessels, piping and storage tanks. In the present work, the authors present the integrity assessment performed on this tank using the Fitness for Service approach using the methods and procedures contained in the document API RP 579 (Fitness-for-service). (author)

Gold grade variation and particle microchemistry in exploration pits of the Batouri gold district, SE Cameroon

Science.gov (United States)

Vishiti, A.; Suh, C. E.; Lehmann, B.; Egbe, J. A.; Shemang, E. M.

2015-11-01

The Batouri area hosts lode-gold mineralization under several-m-thick lateritic cover. Pitting to bed rock on a geochemical Au anomaly defined from previous reconnaissance soil sampling identified five horizons ranging from saprock at the base to laterite at the top. Analysis of bulk samples from each horizon by fire assay shows that most of the horizons are barren although 119 ppb and 48 ppb Au values were obtained from one laterite horizon and one saprolite horizon, respectively, from two separate pits. All the horizons were panned and particulate gold was also recovered only from these two horizons. The gold grains from both horizons are morphologically and compositionally indistinguishable with rare quartz, pyrite and galena inclusions. The grains have irregular, sub-rounded, bean to elongated shapes and they show a remarkable core-rim zonation. Electron microprobe analysis of the grains recorded high gold content in the rims (86.3-100 wt%) and along fissures within the grains (95.1-100 wt%). The cores are relatively Ag rich (11.8-14 wt% Ag) while the rims (0.63-13.7 wt% Ag, most of the values fall within the lower limit of this range) and fissures (0.03-5.02 wt% Ag) are poor in Ag. The low Ag concentration in the rims and along fissures is attributed to preferential leaching of Ag; a process recognized in gold grains and platiniferous alloys from alluvia. The core composition of the grains is similar to that of primary gold composition in the bedrock. These results show that gold in the soil is relic particulate gold derived from the primary source with no evidence of secondary gold precipitation in the weathering cycle. In all the pits no horizon was systematically enriched in gold suggesting there has been no chemical remobilization of gold in this environment. Rather the dispersion of gold here is in the particulate form. Therefore combining particulate gold features with assay data is relevant to exploration in such tropical environments.

Crystallographic orientation study of silicon steels using X-ray diffraction, electrons diffraction and the Etch Pit method

International Nuclear Information System (INIS)

Santos, Hamilta de Oliveira

1999-01-01

The aim of the present study is the microstructural and crystallographic orientation of Fe-3%Si steel. The silicon steel shows good electrical properties and it is used in the nuclear and electrical power fields. The studied steel was supplied by Cia. Acos Especiais Itabira S/A - ACESITA. The material was received in the hot compressed condition, in one or two passes. The hot compressing temperatures used were 900, 1000 and 1100 deg C with soaking times ranging from 32 to 470 s. The material preferential crystallographic orientation was evaluated in every grain of the samples. The characterization techniques used were: scanning electron microscopy (SEM) using the etch pit method; X ray diffraction using the Laue back-reflection method; orientation imaging microscopy (OIM). Microstructural characterization in terms of grain size measurement and mean number of grains in the sample were also undertaken. The Laue method was found an easy technique to access crystallographic orientation of this work polycrystalline samples 2.5 mm average grain size. This was due to the inability to focus the X-rays on a single grain of the material. The scanning electron microscopy showed microcavities left by the etch pit method, which allowed the observation of the crystallographic orientation of each grain from the samples. No conclusive grain crystallographic orientation was possible to obtain by the OIM technique due to the non-existing rolling direction. A more extensive work with the OIM technique must be undertaken on the Fe-3%Si with oriented grains and non oriented grains. (author)

Integrated transcriptomics and proteomics analysis of storage protein composition in developing barley grain to improve nutritional profile

DEFF Research Database (Denmark)

Kaczmarczyk, Agnieszka Ewa; Dionisio, Giuseppe; Renaut, Jenny

2012-01-01

The aim of the study was to understand the molecular and biochemical mechanisms underpinning the effect of nitrogen (N) on barley (Hordeum vulgare) storage protein production (hordeins) during grain filling. Using a combination of advanced biochemistry methods, we could comprehensively describe c...

Ochratoxin A in grain dust--estimated exposure and relations to agricultural practices in grain production.

Science.gov (United States)

Halstensen, Anne Straumfors; Nordby, Karl-Christian; Elen, Oleif; Eduard, Wijnand

2004-01-01

Ochratoxin A (OTA) is a nephrotoxin frequently contaminating grains. OTA inhalation during grain handling may therefore represent a health risk to farmers, and was the subject of this study. Airborne and settled grain dust was collected during grain work on 84 Norwegian farms. Climate and agricultural practices on each farm were registered. Penicillium spp., Aspergillus spp. and OTA in settled dust were measured. Settled dust contained median 4 microg OTA/kg dust (range 2-128), correlating with Penicillium spp. (median 40 cfu/mg; range 0-32000, rs =0.33; p grain species, districts and agricultural practices. Penicillium levels, but not OTA levels, were higher in storage than in threshing dust (p=0.003), and increased with storage time (rs =0.51, p dust during threshing and median 7 mg/m3 (range 1-110) dust during storage work, equalling median 3.7 pg/m3 (range 0.6-200) and median 40 pg/m3 (range 2-14000) OTA, respectively (p grain work was low, although varying by more than 1,000-fold. However, the farmers may occasionally be highly exposed, particularly during handling of stored grain.

Integrated transcriptomics and proteomics analysis of storage protein composition in developing barley grain to improve nutritional profile

DEFF Research Database (Denmark)

Kaczmarczyk, Agnieszka Ewa; Dionisio, Giuseppe; Renaut, Jenny

2012-01-01

The aim of the study was to understand the molecular and biochemical mechanisms underpinning the effect of nitrogen (N) on barley (Hordeum vulgare) storage protein production (hordeins) during grain filling. Using a combination of advanced biochemistry methods, we could comprehensively describe......-regimes caused significant differences in both quantity and quality of the storage proteins transcripts. Principal Component Analysis of the amino acid (AA) profiles also indicated dissimilarity in individual AA percentages, correlated to hordein content. The abundance values of proteins of interest confirmed...

Simulation of Multi Canister Overpack (MCO) Handling Machine Impact with Cask and MCO During Insertion into the Transfer Pit (FDT-137)

Energy Technology Data Exchange (ETDEWEB)

BAZINET, G.D.

2000-04-13

The K-Basin Cask and Transportation System will be used for safely packaging and transporting approximately 2,100 metric tons of unprocessed, spent nuclear fuel from the 105 K East and K West Basins to the 200 E Area Canister Storage Building (CSB). Portions of the system will also be used for drying the spent fuel under cold vacuum conditions prior to placement in interim storage. The spent nuclear fuel is currently stored underwater in the two K-Basins. The K-Basins loadout pit is the area selected for loading spent nuclear fuel into the Multi-Canister Overpack (MCO) which in turn is located within the transportation cask. This Cask/MCO unit is secured.in the pit with a pail load out structure whose primary function is lo suspend and support the Cask/MCO unit at.the desired elevations and to protect the unit from the contaminated K-Basin water. The fuel elements will be placed in special baskets and stacked in the MCO that have been previously placed in the cask. The casks will be removed from the K Basin load out areas and taken to the cold vacuum drying station. Then the cask will be prepared for transportation to the CSB. The shipments will occur exclusively on the Hanford Site between K-Basins and the CSB. Travel will be by road with one cask per trailer. At the CSB receiving area the cask will be removed from the trailer. A gantry crane will then move the cask over to the transfer pit and load the cask into the transfer pit. From the transfer pit the MCO will be removed from the cask by the MCO Handling Machine (MHM). The MHM will move the MCO from the transfer pit to a canister storage tube in the CSB. MCOs will be piled two high in each canister Storage tube.

Simulation of Multi Canister Overpack (MCO) Handling Machine Impact with Cask and MCO During Insertion into the Transfer Pit (FDT-137)

International Nuclear Information System (INIS)

BAZINET, G.D.

2000-01-01

The K-Basin Cask and Transportation System will be used for safely packaging and transporting approximately 2,100 metric tons of unprocessed, spent nuclear fuel from the 105 K East and K West Basins to the 200 E Area Canister Storage Building (CSB). Portions of the system will also be used for drying the spent fuel under cold vacuum conditions prior to placement in interim storage. The spent nuclear fuel is currently stored underwater in the two K-Basins. The K-Basins loadout pit is the area selected for loading spent nuclear fuel into the Multi-Canister Overpack (MCO) which in turn is located within the transportation cask. This Cask/MCO unit is secured.in the pit with a pail load out structure whose primary function is lo suspend and support the Cask/MCO unit at.the desired elevations and to protect the unit from the contaminated K-Basin water. The fuel elements will be placed in special baskets and stacked in the MCO that have been previously placed in the cask. The casks will be removed from the K Basin load out areas and taken to the cold vacuum drying station. Then the cask will be prepared for transportation to the CSB. The shipments will occur exclusively on the Hanford Site between K-Basins and the CSB. Travel will be by road with one cask per trailer. At the CSB receiving area the cask will be removed from the trailer. A gantry crane will then move the cask over to the transfer pit and load the cask into the transfer pit. From the transfer pit the MCO will be removed from the cask by the MCO Handling Machine (MHM). The MHM will move the MCO from the transfer pit to a canister storage tube in the CSB. MCOs will be piled two high in each canister Storage tube

A cooling concept of spent fuels in lag storage system

International Nuclear Information System (INIS)

Park, Jeong-Hwa; Yoo, Jae-Hyung; Park, Hyun-Soo

1991-01-01

A cooling concept of spent fuels by natural convection of hot cell air in storage pits was developed. Each storage pit was considered to be located below the hot cell floor and to accommodate only one spent fuel assembly. The aim of this study is to apply an appropriate cooling system to the design of a hot cell where considerable heat-generating fuels are handled. In such operations as disassembling, rod consolidation and packaging of spent fuels, a number of assemblies are on stand-by in the cell before and/or after the operations. A lag storage system can be used for temporary storage of spent fuels in nuclear facilities. Since the air in contact with bare fuel assemblies is potentially contaminated, it must be exhausted through high-efficiency particulate air (HEPA) filters. If the storage pit is completely isolated from the hot cell space, then it will require another separate ventilation system by forced convection of air, which will result in additional cost for the construction. In this work, however, a cooling system was proposed where natural convection of hot cell air itself is achieved by thermo-syphon. The cold air from the hot cell is supplied to the inlet provided at the bottom of each pit through the gap between the concrete pit wall and the interior thermal shield. This thermal shield is needed to form flow channels for cold and heated air, and to prevent the concrete from over-heating. The heated air exhausts from the outlet located at the top of cell wall. No additional HEPA filters are needed in this system because the heated air is routed back to the hot cell due to buoyancy-induced flow. The technical feasibility of this concept was validated by thermal analyses. As the key design constraints are the surface temperature of fuel cladding and the concrete temperature of the storage pit, the thermal analyses were focused on these parameters whether they follow within allowable limits or not. (author)

Stored-grain insect population commingling densities in wheat and corn from pilot-scale bucket elevator boots

Science.gov (United States)

Grain elevator boot and pit areas facilitate the commingling of insects with the grain moving through the elevator leg. A removable boot was developed to facilitate residual grain removal and preservation in the boot and to quantify the commingling magnitude as a function of stored-product insect de...

Yield and acidity indices of sunflower and soybean oils in function of grain drying and storage

Directory of Open Access Journals (Sweden)

Paulo Carteri Coradi

2017-04-01

Full Text Available The aim of this study was to identify the best conditions for drying and storing soybeans and sunflower grains to maintain their quality. In the first experiment, the soybeans were found to have initial moisture contents of 25 and 19% (w.b. at different drying air temperatures (75, 90, 105, and 120°C. In the second step, the soybeans were evaluated after they were stored in paper bags and plastic polyethylene at temperatures of 3, 10 and 23°C for six months. In the third experiment, sunflower grains were tested after exposure to drying air temperatures of 45, 55, 65, and 75°C, and under storage conditions of 25°C and 50%, 20°C and 60%, 30°C and 40% RH over six months in paper bags and raffia. Drying the sunflower seeds at 45°C and storing them at 30°C and 40% RH led to higher oil yields and lower acid numbers. The oil that was extracted from the acid number was higher for soybean grains that were dried down from initial concentrations of 25% water at a drying air temperature of 120°C. The air temperature in storage at 3°C favored for yield and reduction of the soybean oil acidity.

AT-400A Type B transportation and storage package

International Nuclear Information System (INIS)

Cockrell, G.D.; Franklin, K.W.

1995-01-01

This paper discusses the design considerations for the AT-400A container which will meet the requirements for the transportation and long-term storage of plutonium pits. The AT-400A was designed by a joint effort between Sandia National Labs, Los Alamos National Labs, Lawrence Livermore National Laboratory, and Mason and Hanger Silas Mason Co., Inc.. The paper will outline the problems and impact on the design of the container necessitated by the need to meet DOT TYPE B transportation requirements and undefined requirements for the interim and long-term storage of pits. Areas covered will include: (1) determining the storage requirements, (2) surveillance program for interim storage, and (3) impact of storage requirements on the containment vessel and inner fixturing design

Underground Pumped Storage Hydropower using abandoned open pit mines: influence of groundwater seepage on the system efficiency

Science.gov (United States)

Pujades, Estanislao; Bodeux, Sarah; Orban, Philippe; Dassargues, Alain

2016-04-01

Pumped Storage Hydropower (PSH) plants can be used to manage the production of electrical energy according to the demand. These plants allow storing and generating electricity during low and high demand energy periods, respectively. Nevertheless, PSH plants require a determined topography because two reservoirs located at different heights are needed. At sites where PSH plants cannot be constructed due to topography requirements (flat regions), Underground Pumped Storage Hydropower (UPSH) plants can be used to adjust the electricity production. These plants consist in two reservoirs, the upper one is located at the surface (or at shallow depth) while the lower one is underground (or deeper). Abandoned open pit mines can be used as lower reservoirs but these are rarely isolated. As a consequence, UPSH plants will interact with surrounding aquifers exchanging groundwater. Groundwater seepage will modify hydraulic head inside the underground reservoir affecting global efficiency of the UPSH plant. The influence on the plant efficiency caused by the interaction between UPSH plants and aquifers will depend on the aquifer parameters, underground reservoir properties and pumping and injection characteristics. The alteration of the efficiency produced by the groundwater exchanges, which has not been previously considered, is now studied numerically. A set of numerical simulations are performed to establish in terms of efficiency the effects of groundwater exchanges and the optimum conditions to locate an UPSH plant.

Pitting and Stress Corrosion Cracking Susceptibility of Nanostructured Al-Mg Alloys in Natural and Artificial Environments

Science.gov (United States)

Sharma, Mala M.; Ziemian, Constance W.

2008-12-01

The stress corrosion cracking (SCC) behavior of two developmental nanocrystalline 5083 alloys with varied composition and processing conditions was studied. The results were compared to a commercial aluminum AA 5083 (H111) alloy. The pitting densities, size and depths, and residual tensile strengths were measured after alternate immersion in artificial seawater and atmospheric exposure under different loading conditions. Optical and scanning electron microscopy (SEM) with EDX was used to analyze the fracture surfaces of failed specimen after removal at selected intervals and tensile testing. One of the nanostructured Al-Mg alloys exhibited significantly superior pitting resistance when compared to conventional microstructured AA 5083. Under conditions where pitting corrosion showed up as local tunnels toward phase inclusions, transgranular cracking was observed, whereas under conditions when pitting corrosion evolved along grain boundaries, intergranular cracking inside the pit was observed. Pit initiation resistance of the nano alloys appears to be better than that of the conventional alloys. However, long-term pit propagation is a concern and warrants further study. The objective of this investigation was to obtain information regarding the role that ultra-fine microstructures play in their degradation in marine environments and to provide insight into the corrosion mechanisms and damage processes of these alloys.

Mycotoxin production in wheat grains by different Aspergilli in relation to different relative humidities and storage periods.

Science.gov (United States)

Atalla, Mohamed Mabrouk; Hassanein, Naziha Mohamed; El-Beih, Ahmed Atef; Youssef, Youssef Abdel-ghany

2003-02-01

Four different Aspergilli (Aspergillus oryzae, A. parasiticus, A. terreus and A. versicolor) were grown on wheat grains underdifferent degrees of relative humidity 14, 50, 74, 80 and 90%. Samples of wheat grains were taken monthly for a period of six months and examined for mycotoxin production. A. oryzae was found to produce aflatoxins B1, B2, zearalenone, DON and T-2 toxins under elevated degrees of humidity and prolonged periods of storage. A. parasiticus produced aflatoxins B1, G1, NIV, DON and T-2 toxins in high concentrations during a period of not more than three months storage at 14% relative humidity; at an increased level of relative humidity of 74% ochratoxin A, zearalenone and sterigmatocystin were also produced at high levels. The isolate was drastic in toxin production. A. terrus produced toxins at 14% relative humidity (aflatoxin G2 and DON) at levels much higher than any other prevalent degrees of humidity. A. versicolor is highly sensitive to relative humidity and grain moisture content It produced aflatoxins B1, G1, NIV and DON at a relative humidity of 50% and another toxins (aflatoxin G2, ochratoxins A, B and zearalenone) at 74%. The microorganism can be considered a trichothecene producer under suitable relative humidity.

Influence of Step Annealing Temperature on the Microstructure and Pitting Corrosion Resistance of SDSS UNS S32760 Welds

Science.gov (United States)

Yousefieh, M.; Shamanian, M.; Saatchi, A.

2011-12-01

In the present work, the influence of step annealing heat treatment on the microstructure and pitting corrosion resistance of super duplex stainless steel UNS S32760 welds have been investigated. The pitting corrosion resistance in chloride solution was evaluated by potentiostatic measurements. The results showed that step annealing treatments in the temperature ranging from 550 to 1000 °C resulted in a precipitation of sigma phase and Cr2N along the ferrite/austenite and ferrite/ferrite boundaries. At this temperature range, the metastable pits mainly nucleated around the precipitates formed in the grain boundary and ferrite phase. Above 1050 °C, the microstructure contains only austenite and ferrite phases. At this condition, the critical pitting temperature of samples successfully arrived to the highest value obtained in this study.

Effects of heat input on pitting corrosion in super duplex stainless steel weld metals

Science.gov (United States)

Shin, Yong taek; Shin, Hak soo; Lee, Hae woo

2012-12-01

Due to the difference in reheating effects depending on the heat input of subsequent weld passes, the microstructure of the weld metal varies between acicular type austenite and a mixture of polygonal type and grain boundary mixed austenite. These microstructural changes may affect the corrosion properties of duplex stainless steel welds. This result indicates that the pitting resistance of the weld can be strongly influenced by the morphology of the secondary austenite phase. In particular, the ferrite phase adjacent to the acicular type austenite phase shows a lower Pitting Resistance Equivalent (PRE) value of 25.3, due to its lower chromium and molybdenum contents, whereas the secondary austenite phase maintains a higher PRE value of more than 38. Therefore, it can be inferred that the pitting corrosion is mainly due to the formation of ferrite phase with a much lower PRE value.

Final work plan : investigation of potential contamination at the former CCC/USDA grain storage facility in Hanover, Kansas.

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M.; Environmental Science Division

2008-11-19

The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), operated a grain storage facility at the northeastern edge of the city of Hanover, Kansas, from 1950 until the early 1970s. During this time, commercial grain fumigants containing carbon tetrachloride were in common use by the grain storage industry to preserve grain in their facilities. In February 1998, trace to low levels of carbon tetrachloride (below the maximum contaminant level [MCL] of 5.0 {micro}g/L) were detected in two private wells near the former grain storage facility at Hanover, as part of a statewide USDA private well sampling program that was implemented by the Kansas Department of Health and Environment (KDHE) near former CCC/USDA facilities. In April 2007, the CCC/USDA collected near-surface soil samples at 1.8-2 ft BGL (below ground level) at 61 locations across the former CCC/USDA facility. All soil samples were analyzed by the rigorous gas chromatograph-mass spectrometer analytical method (purge-and-trap method). No contamination was found in soil samples above the reporting limit of 10 {micro}g/kg. In July 2007, the CCC/USDA sampled indoor air at nine residences on or adjacent to its former facility to address the residents concerns regarding vapor intrusion. Low levels of carbon tetrachloride were detected at four of the nine homes. Because carbon tetrachloride found in private wells and indoor air at the site might be linked to historical use of fumigants containing carbon tetrachloride at its former grain storage facility, the CCC/USDA is proposing to conduct an investigation to determine the source and extent of the carbon tetrachloride contamination associated with the former facility. This investigation will be conducted in accordance with the intergovernmental agreement between the KDHE and the Farm Service Agency (FSA) of the USDA. The investigation at Hanover will be performed, on behalf of the CCC/USDA, by the Environmental Science

Pitting corrosion as a mixed system: coupled deterministic-probabilistic simulation of pit growth

Science.gov (United States)

Ibrahim, Israr B. M.; Fonna, S.; Pidaparti, R.

2018-05-01

Stochastic behavior of pitting corrosion poses a unique challenge in its computational analysis. However, it also stems from electrochemical activity causing general corrosion. In this paper, a framework for corrosion pit growth simulation based on the coupling of the Cellular Automaton (CA) and Boundary Element Methods (BEM) is presented. The framework assumes that pitting corrosion is controlled by electrochemical activity inside the pit cavity. The BEM provides the prediction of electrochemical activity given the geometrical data and polarization curves, while the CA is used to simulate the evolution of pit shapes based on electrochemical activity provided by BEM. To demonstrate the methodology, a sample case of local corrosion cells formed in pitting corrosion with varied dimensions and polarization functions is considered. Results show certain shapes tend to grow in certain types of environments. Some pit shapes appear to pose a higher risk by being potentially significant stress raisers or potentially increasing the rate of corrosion under the surface. Furthermore, these pits are comparable to commonly observed pit shapes in general corrosion environments.

Influence of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel welding joints

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhiqiang; Jing, Hongyang [School of Materials Science and Engineering, Tianjin University, Tianjin 300350 (China); Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300350 (China); Xu, Lianyong, E-mail: xulianyong@tju.edu.cn [School of Materials Science and Engineering, Tianjin University, Tianjin 300350 (China); Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300350 (China); Han, Yongdian; Zhao, Lei [School of Materials Science and Engineering, Tianjin University, Tianjin 300350 (China); Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300350 (China); Zhang, Jianli [Welding laboratory, Offshore Oil Engineering (Qing Dao) Company, Qing Dao 266520 (China)

2017-02-01

Highlights: • N{sub 2}-supplemented shielding gas promoted nitrogen solid-solution in the austenite. • Secondary austenite had higher Ni but lower Cr and Mo than primary austenite. • Pitting corrosion preferentially occurred at secondary austenite and Cr{sub 2}N. • Adding N{sub 2} in shielding gas improved pitting corrosion resistance of GTAW joint. • E2209T{sub 1} weld metal had very poor pitting corrosion resistance due to inclusions. - Abstract: The influences of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel joints welded by gas tungsten arc welding (GTAW) and flux-cored arc welding (FCAW) with different shielding gas compositions were studied by optical microscopy, electron backscatter diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, electron probe microanalysis, and potentiostatic and potentiodynamic polarization methods The adding 2% N{sub 2} in shielding gas facilitated primary austenite formation in GTAW weld metal (WM) and suppressed Cr{sub 2}N precipitation in GTAW weld root. In the HAZ, the banded microstructure disappeared while the coarse ferrite grains maintained same orientation as the banded ferrite in the BM. In the WM, the ferrite had one single orientation throughout a grain, whereas several families of austenite appeared. The austenite both in BM and WM enriched in Ni and nitrogen, while Cr and Mo were concentrated in the ferrite and thus no element showed clear dendritic distribution in the WM (ER2209 and E2209T{sub 1}). In addition, the secondary austenite had higher Ni content but lower Cr and Mo content than the primary austenite. The N{sub 2}-supplemented shielding gas promoted nitrogen solid-solution in the primary and secondary austenite. Furthermore, the secondary austenite had relatively lower pitting resistance equivalent number (PREN) than the ferrite and primary austenite, thereby resulting in its preferential

Influence of grain size on lithium storage performance of germanium oxide films

International Nuclear Information System (INIS)

Feng, J.K.; Lai, M.O.; Lu, L.

2012-01-01

Highlights: ► We deposited GeO 2 thin films at different temperatures to form different grain sizes. ► Li storage of GeO 2 as anode was studied, which shows that the GeO 2 with grain size of about 10 nm reveals high capacity retention. ► Nanograined GeO 2 also shows better rate capability and cyclability. - Abstract: Germanium oxide (GeO 2 ) films with two different grain sizes of 10 nm (GeO 2 (10 nm)) and 100 nm (GeO 2 (100 nm)) were grown via reactive radio frequency sputtering at different temperatures. Electrochemical measurements of the GeO 2 (10 nm) thin film used as an anode in Li ion rechargeable batteries show superior capacity retention and rate capability compared to those of GeO 2 (100 nm). The GeO 2 (10 nm) thin film possesses an initial capacity of 930 mAh g −1 with 89% capacity retention after 100 cycles, compared with 455 mAh g −1 with 53% of GeO 2 (100 nm) and 225 mAh g −1 , 30% (10 cycles) of common macro-size GeO 2 . Microstructural studies reveal that the GeO 2 (10 nm) thin film can better accommodate volume changes during Li–Ge alloying and de-alloying processes.

A Study on Microstructure Change and Pitting Corrosion Resistance of Ferritic Stainless Steel Weldment According to Nb Contents

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong-Min; Shin, Yong-Taek; Lee, Sang-Hwa; Lee, Jun-Hee; Lee, Hae-Woo [Dong-A University, Busan (Korea, Republic of); Lee, Sung-Riong [Kangwon National University, ChunCheon (Korea, Republic of); Kim, Soon-Ho [Silla University, Busan (Korea, Republic of)

2014-01-15

This paper identified the effects of Nb on microstructure. Also, it has studied on uniform and pitting corrosion resistance in a ferritic stainless steel weld metal of the automobile exhaust system. We fabricated 3 flux cored wires designed with 0-1.0 wt% Nb and performed Flux Cored Arc Welding. We observed the microstructure with the SEM/EDS and EBSD. To evaluate the uniform and pitting corrosion resistance, we performed a potentiodynamic polarization test in 0.2 M H{sub 2}SO{sub 4} and 0.1, 0.3, 0.5 M NaCl. As a result of the tests, we found that as the amount of addition of Nb rose, the amount of Cr-carbide fell. The microstructure became more refined. The specimen with 1.0%Nb added had the highest uniform and pitting corrosion resistance. After the pitting corrosion test, a pit was formed at the grain boundary that has no addition of Nb. In addition, in the specimen with added Nb, pits were formed at the inclusions.

Is Playing in the Pit Really the Pits?: Pain, Strength, Music Performance Anxiety, and Workplace Satisfaction in Professional Musicians in Stage, Pit, and Combined Stage/Pit Orchestras.

Science.gov (United States)

Kenny, Dianna T; Driscoll, Tim; Ackermann, Bronwen J

2016-03-01

Typically, Australian orchestral musicians perform on stage, in an orchestra pit, or in a combination of both workplaces. This study explored a range of physical and mental health indicators in musicians who played in these different orchestra types to ascertain whether orchestra environment was a risk factor affecting musician wellbeing. Participants comprised 380 full-time orchestral musicians from the eight major state orchestras in Australia comprised of two dedicated pit orchestras, three stage-only symphonic orchestras, and three mixed stage/pit orchestras. Participants completed a physical assessment and a range of self-report measures assessing performance-related musculoskeletal disorders (PRMD), physical characteristics including strength and perceived exertion, and psychological health, including music performance anxiety (MPA), workplace satisfaction, and bullying. Physical characteristics and performance-related musculoskeletal profiles were similar for most factors on the detailed survey completed by orchestra members. The exceptions were that pit musicians demonstrated greater shoulder and elbow strength, while mixed-workload orchestra musicians had greater flexibility Significantly more exertion was reported by pit musicians when rehearsing and performing. Stage/pit musicians reported less physical exertion when performing in the pit compared with performing on stage. Severity of MPA was significantly greater in pit musicians than mixed orchestra musicians. Pit musicians also reported more frequent bullying and lower job satisfaction compared with stage musicians. There were few differences in the objective physical measures between musicians in the different orchestra types. However, pit musicians appear more psychologically vulnerable and less satisfied with their work than musicians from the other two orchestra types. The physical and psychological characteristics of musicians who perform in different orchestra types have not been adequately

Design-only conceptual design report for pit disassembly and conversion facility. Rev 0

International Nuclear Information System (INIS)

Zygmunt, S.; Christensen, L.; Richardson, C.

1997-01-01

This design-only conceptual design report (DOCDR) was prepared to support a funding request by the Department of Energy (DOE)-Office of Fissile Material Disposition (OFMD) for engineering design of the Pit Disassembly and Conversion Facility (PDCF) Project No. 99-D-141. The PDCF will be used to disassemble the nation's inventory of surplus nuclear weapons pits and convert the plutonium recovered from those pits into a form suitable for storage, international inspection, and final disposition. The PDCF is a complex consisting of a hardened building that will contain the plutonium processes in a safe and secure manner, and conventional buildings and structures that will house support personnel, systems, and equipment. The PDCF uses the Advanced Recovery and Integrated Extraction System (ARIES), a low waste, modular pyroprocessing system to convert pits to plutonium oxide. The PDCF project consists of engineering and design, and construction of the buildings and structures, and engineering and design, procurement, installation, testing and start-up of equipment to disassemble pits and convert plutonium in pits to oxide form. The facility is planned to operate for 10 years, averaging 3.5 metric tons (3.86 tons) of plutonium metal per year. On conclusion of operations, the PDCF will be decontaminated and decommissioned

Design-only conceptual design report for pit disassembly and conversion facility. Rev 0

Energy Technology Data Exchange (ETDEWEB)

Zygmunt, S.; Christensen, L.; Richardson, C.

1997-12-12

This design-only conceptual design report (DOCDR) was prepared to support a funding request by the Department of Energy (DOE)-Office of Fissile Material Disposition (OFMD) for engineering design of the Pit Disassembly and Conversion Facility (PDCF) Project No. 99-D-141. The PDCF will be used to disassemble the nation`s inventory of surplus nuclear weapons pits and convert the plutonium recovered from those pits into a form suitable for storage, international inspection, and final disposition. The PDCF is a complex consisting of a hardened building that will contain the plutonium processes in a safe and secure manner, and conventional buildings and structures that will house support personnel, systems, and equipment. The PDCF uses the Advanced Recovery and Integrated Extraction System (ARIES), a low waste, modular pyroprocessing system to convert pits to plutonium oxide. The PDCF project consists of engineering and design, and construction of the buildings and structures, and engineering and design, procurement, installation, testing and start-up of equipment to disassemble pits and convert plutonium in pits to oxide form. The facility is planned to operate for 10 years, averaging 3.5 metric tons (3.86 tons) of plutonium metal per year. On conclusion of operations, the PDCF will be decontaminated and decommissioned.

Final work plan : supplemental upward vapor intrusion investigation at the former CCC/USDA grain storage facility in Hanover, Kansas.

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M.; Environmental Science Division

2008-12-15

The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), operated a grain storage facility at the northeastern edge of the city of Hanover, Kansas, from 1950 until the early 1970s. During this time, commercial grain fumigants containing carbon tetrachloride were in common use by the grain storage industry to preserve grain in their facilities. In February 1998, trace to low levels of carbon tetrachloride (below the maximum contaminant level [MCL] of 5.0 {micro}g/L) were detected in two private wells near the former grain storage facility at Hanover, as part of a statewide USDA private well sampling program that was implemented by the Kansas Department of Health and Environment (KDHE) near former CCC/USDA facilities. In 2007, the CCC/USDA conducted near-surface soil sampling at 61 locations and also sampled indoor air at nine residences on or adjacent to its former Hanover facility to address the residents concerns regarding vapor intrusion. Low levels of carbon tetrachloride were detected at four of the nine homes. The results were submitted to the KDHE in October 2007 (Argonne 2007). On the basis of the results, the KDHE requested sub-slab sampling and/or indoor air sampling (KDHE 2007). This Work Plan describes, in detail, the proposed additional scope of work requested by the KDHE and has been developed as a supplement to the comprehensive site investigation work plan that is pending (Argonne 2008). Indoor air samples collected previously from four homes at Hanover were shown to contain the carbon tetrachloride at low concentrations (Table 2.1). It cannot be concluded from these previous data that the source of the detected carbon tetrachloride is vapor intrusion attributable to former grain storage operations of the CCC/USDA at Hanover. The technical objective of the vapor intrusion investigation described here is to assess the risk to human health due to the potential for upward migration of carbon tetrachloride and

Corrective Action Decision Document for Corrective Action Unit 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site, Nevada, Revision 1 with ROTC 1

International Nuclear Information System (INIS)

Boehlecke, Robert

2004-01-01

This Corrective Action Decision Document (CADD) has been prepared for Corrective Action Unit (CAU) 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site (NTS), Nevada, in accordance with the ''Federal Facility Agreement and Consent Order'' (1996). Corrective Action Unit 140 is located within Areas 5, 22, and 23 of the NTS and is comprised of the following corrective action sites (CASs): 05-08-01, Detonation Pits; 05-08-02, Debris Pits; 05-17-01, Hazardous Waste Accumulation Site (Buried); 05-19-01, Waste Disposal Site; 05-23-01, Gravel Gertie; 05-35-01, Burn Pit; 05-99-04, Burn Pit; 22-99-04, Radioactive Waste Dump; and 23-17-01, Hazardous Waste Storage Area. The purpose of this CADD is to identify and provide a rationale for the recommendation of a corrective action alternative for each CAS within CAU 140. Corrective action investigation activities were performed from November 13 through December 11, 2002. Additional sampling to delineate the extent of contaminants of concern (COCs) was conducted on February 4 and March 18 and 19, 2003. Corrective action investigation activities were performed as set forth in the Corrective Action Investigation Plan for CAU 140. Analytes detected during the corrective action investigation were evaluated against appropriate preliminary action levels to identify COCs for each CAS. Assessment of the data generated from investigation activities revealed the following: (1) CAS 05-08-01 contains the COCs lead and the radioisotope thorium-234 in the surface soil at sample location A05. (2) CAS 05-23-01 did not have any COCs identified during the field investigation; however, based on historical knowledge of activities at this site, the interior of the Gravel Gertie is considered contaminated with uranium. (3) CAS 23-17-01 contains the COC total petroleum hydrocarbons (diesel-range organics) at location J20 at a depth of 9 to 10 feet below ground surface. (4) No COCs were identified at CASs 05-08-02, 05-17-01, 05-19-01, 05

Electrochemical study of the AISI 409 ferritic stainless steel: passive film stability and pitting nucleation and growth

International Nuclear Information System (INIS)

Souza, Juliana Sarango de; Oliveira, Leandro Antônio de; Antunes, Renato Altobelli; Sayeg, Isaac Jamil

2017-01-01

The aim of the present work was to study the passive film stability and pitting corrosion behavior of the AISI 409 stainless steel. The electrochemical tests were carried out in 0.1 M NaCl solution at room temperature. The general electrochemical behavior was assessed using electrochemical impedance spectroscopy (EIS) measurements whereas the semiconducting properties of the passive film were evaluated by the Mott-Schottky approach. Pitting corrosion was investigated using potentiodynamic and potentiostatic polarization tests. Surface morphology was examined using confocal laser scanning microscopy and scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy (EDS) analyses were carried out to identify the composition of precipitates that could act as preferential sites for the onset of pitting corrosion. The results showed that the passive film presents n-type semiconductive behavior. Grain boundaries played an important role as pitting initiation sites for the AISI 409 stainless steel. (author)

Electrochemical study of the AISI 409 ferritic stainless steel: passive film stability and pitting nucleation and growth

Energy Technology Data Exchange (ETDEWEB)

Souza, Juliana Sarango de [Universidade Federal de São Paulo (UNIFESP), Diadema, SP (Brazil). Departamento de Ciências Exatas e da Terra; Oliveira, Leandro Antônio de; Antunes, Renato Altobelli, E-mail: renato.antunes@ufabc.edu.br [Universidade Federal do ABC (CECS/UFABC), Santo André, SP (Brazil). Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas; Sayeg, Isaac Jamil [Universidade de São Paulo (USP), SP (Brazil). Instituto de Geociências

2017-11-15

The aim of the present work was to study the passive film stability and pitting corrosion behavior of the AISI 409 stainless steel. The electrochemical tests were carried out in 0.1 M NaCl solution at room temperature. The general electrochemical behavior was assessed using electrochemical impedance spectroscopy (EIS) measurements whereas the semiconducting properties of the passive film were evaluated by the Mott-Schottky approach. Pitting corrosion was investigated using potentiodynamic and potentiostatic polarization tests. Surface morphology was examined using confocal laser scanning microscopy and scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy (EDS) analyses were carried out to identify the composition of precipitates that could act as preferential sites for the onset of pitting corrosion. The results showed that the passive film presents n-type semiconductive behavior. Grain boundaries played an important role as pitting initiation sites for the AISI 409 stainless steel. (author)

CHerenkov detectors In mine PitS (CHIPS) Letter of Intent to FNAL

Energy Technology Data Exchange (ETDEWEB)

Adamson, P. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Austin, J. [Univ. of Minnesota, Duluth, MN (United States); Cao, S. V. [Univ. of Texas, Austin, TX (United States); Coelho, J. A. B. [Tufts Univ., Medford, MA (United States); Davies, G. S. [Iowa State Univ., Ames, IA (United States); Evans, J. J. [Univ. of Manchester (United Kingdom); Guzowski, P. [Univ. of Manchester (United Kingdom); Habig, A. [Univ. of Minnesota, Duluth, MN (United States); Holin, A. [Univ. College London, London (United Kingdom); Huang, J. [Univ. of Texas, Austin, TX (United States); Johnson, R. [Univ. of Cincinnati, OH (United States); St. John, J. [Univ. of Cincinnati, OH (United States); Kreymer, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kordosky, M. [College of William and Mary, Williamsburg, VA (United States); Lang, K. [Univ. of Texas, Austin, TX (United States); Marshak, M. L. [Univ. of Minnesota, Minneapolis, MN (United States); Mehdiyev, R. [Univ. of Texas, Austin, TX (United States); Meier, J. [Univ. of Minnesota, Minneapolis, MN (United States); Miller, W. [Univ. of Minnesota, Minneapolis, MN (United States); Naples, D. [Univ. of Pittsburgh, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nichol, R. J. [Univ. College London, London (United Kingdom); Patterson, R. B. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paolone, V. [Univ. of Pittsburgh, PA (United States); Pawloski, G. [Univ. of Minnesota, Minneapolis, MN (United States); Perch, A. [Univ. College London, London (United Kingdom); Pfutzner, M. [Univ. College London, London (United Kingdom); Proga, M. [Univ. of Texas, Austin, TX (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Radovic, A. [Univ. College London, London (United Kingdom); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Schreiner, S. [Univ. of Minnesota, Minneapolis, MN (United States); Soldner-Rembold, S. [Univ. of Manchester (United Kingdom); Sousa, A. [Univ. of Cincinnati, OH (United States); Thomas, J. [Univ. College London, London (United Kingdom); Vahle, P. [College of William and Mary, Williamsburg, VA (United States); Wendt, C. [Univ. of Wisconsin, Madison, WI (United States); Whitehead, L. H. [Univ. College London, London (United Kingdom); Wojcicki, S. [Stanford Univ., CA (United States)

2013-12-30

This Letter of Intent outlines a proposal to build a large, yet cost-effective, 100 kton fiducial mass water Cherenkov detector that will initially run in the NuMI beam line. The CHIPS detector (CHerenkov detector In Mine PitS) will be deployed in a flooded mine pit, removing the necessity and expense of a substantial external structure capable of supporting a large detector mass. There are a number of mine pits in northern Minnesota along the NuMI beam that could be used to deploy such a detector. In particular, the Wentworth Pit 2W is at the ideal off-axis angle to contribute to the measurement of the CP violating phase. The detector is designed so that it can be moved to a mine pit in the LBNE beam line once that becomes operational.

The Microstructure and Pitting Resistance of Weld Joints of 2205 Duplex Stainless Steel

Science.gov (United States)

Wu, Mingfang; Liu, Fei; Pu, Juan; Anderson, Neil E.; Li, Leijun; Liu, Dashuang

2017-11-01

2205 duplex stainless steel (DSS) was welded by submerged arc welding. The effects of both heat input and groove type on the ferrite/austenite ratio and elemental diffusion of weld joints were investigated. The relationships among welding joint preparation, ferrite/austenite ratio, elemental diffusion, and pitting corrosion resistance of weld joints were analyzed. When the Ni content of the weld wire deposit was at minimum 2-4% higher than that of 2205 DSS base metal, the desired ratio of ferrite/austenite and elemental partitioning between the austenite and ferrite phases were obtained. While the pitting sensitivity of weld metal was higher than that of base metal, the self-healing capability of the passive film of weld metal was better than that of the base metal when a single V-type groove was used. Furthermore, the heat input should be carefully controlled since pitting corrosion occurred readily in the coarse-grained heat-affected zone near the fusion line of welded joints.

The United States pit disassembly and conversion project -- Meeting the MOX fuel specification

International Nuclear Information System (INIS)

Nelson, T.O.; James, C.A.; Kolman, D.G.

1998-01-01

The US is actively involved in demonstrating the disassembly of nuclear weapons pits to an unclassified form readied for disposition. The MOX option is the most likely path forward for plutonium that originated from nuclear weapon pits. The US demonstration line for pit disassembly and conversion is known as ARIES, the advanced recovery and integrated extraction system. The ARIES demonstration line is being used to gather data in an integrated fashion of the technologies needed for pit disassembly and conversion. These activities include the following modules: pit bisection, hydride-dehydride, oxide conversion, canning, electrolytic decontamination, and nondestructive assay (NDA). Pit bisection swages in a pit in half. Hydride-dehydride converts the pit plutonium metal to an unclassified metal button. To convert the plutonium metal to an oxide the US is investigating a number of options. The primary oxide conversion approach involves variations of combining plutonium hydriding and subsequent oxidation. Another approach is to simply oxidize the metal under controlled conditions-direct metal oxidation (DMO). To remove the gallium from the plutonium oxide, a thermal distillation approach is being used. These pyrochemical approaches will substantially reduce the wastes produced for oxide conversion of weapon plutonium, compared to traditional aqueous processing. The packaging of either the plutonium metal or oxide to long term storage criteria involves the canning and electrolytic decontamination modules. The NDA suite of instruments is then used to assay the material in the containers, which enables international verification without the need to open the containers and repackage them. All of these processes are described

Stochastic modeling of pitting corrosion: A new model for initiation and growth of multiple corrosion pits

International Nuclear Information System (INIS)

Valor, A.; Caleyo, F.; Alfonso, L.; Rivas, D.; Hallen, J.M.

2007-01-01

In this work, a new stochastic model capable of simulating pitting corrosion is developed and validated. Pitting corrosion is modeled as the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time for pit initiation is simulated as the realization of a Weibull process. In this way, the exponential and Weibull distributions can be considered as the possible distributions for pit initiation time. Pit growth is simulated using a nonhomogeneous Markov process. Extreme value statistics is used to find the distribution of maximum pit depths resulting from the combination of the initiation and growth processes for multiple pits. The proposed model is validated using several published experiments on pitting corrosion. It is capable of reproducing the experimental observations with higher quality than the stochastic models available in the literature for pitting corrosion

Stochastic modeling of pitting corrosion: A new model for initiation and growth of multiple corrosion pits

Energy Technology Data Exchange (ETDEWEB)

Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400 Havana (Cuba); Caleyo, F. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)]. E-mail: fcaleyo@gmail.com; Alfonso, L. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico); Rivas, D. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico); Hallen, J.M. [Departamento de Ingenieria, Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)

2007-02-15

In this work, a new stochastic model capable of simulating pitting corrosion is developed and validated. Pitting corrosion is modeled as the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time for pit initiation is simulated as the realization of a Weibull process. In this way, the exponential and Weibull distributions can be considered as the possible distributions for pit initiation time. Pit growth is simulated using a nonhomogeneous Markov process. Extreme value statistics is used to find the distribution of maximum pit depths resulting from the combination of the initiation and growth processes for multiple pits. The proposed model is validated using several published experiments on pitting corrosion. It is capable of reproducing the experimental observations with higher quality than the stochastic models available in the literature for pitting corrosion.

Influence of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel welding joints

Science.gov (United States)

Zhang, Zhiqiang; Jing, Hongyang; Xu, Lianyong; Han, Yongdian; Zhao, Lei; Zhang, Jianli

2017-02-01

The influences of microstructure and elemental partitioning on pitting corrosion resistance of duplex stainless steel joints welded by gas tungsten arc welding (GTAW) and flux-cored arc welding (FCAW) with different shielding gas compositions were studied by optical microscopy, electron backscatter diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, electron probe microanalysis, and potentiostatic and potentiodynamic polarization methods The adding 2% N2 in shielding gas facilitated primary austenite formation in GTAW weld metal (WM) and suppressed Cr2N precipitation in GTAW weld root. In the HAZ, the banded microstructure disappeared while the coarse ferrite grains maintained same orientation as the banded ferrite in the BM. In the WM, the ferrite had one single orientation throughout a grain, whereas several families of austenite appeared. The austenite both in BM and WM enriched in Ni and nitro`gen, while Cr and Mo were concentrated in the ferrite and thus no element showed clear dendritic distribution in the WM (ER2209 and E2209T1). In addition, the secondary austenite had higher Ni content but lower Cr and Mo content than the primary austenite. The N2-supplemented shielding gas promoted nitrogen solid-solution in the primary and secondary austenite. Furthermore, the secondary austenite had relatively lower pitting resistance equivalent number (PREN) than the ferrite and primary austenite, thereby resulting in its preferential corrosion. The Cr2N precipitation led to relatively poor resistance to pitting corrosion in three HAZs and pure Ar shielding GTAW weld root. The N2-supplemented shielding gas improved pitting corrosion resistance of GTAW joint by increasing PREN of secondary austenite and suppressing Cr2N precipitation. In addition, the FCAW WM had much poorer resistance to pitting corrosion than the GTAW WM due to many O-Ti-Si-Mn inclusions. In the BM, since the austenite with lower PREN compared

Testing of intergranular and pitting corrosion in sensitized welded joints of austenitic stainless steel

Directory of Open Access Journals (Sweden)

Bore V. Jegdic

2017-06-01

Full Text Available Pitting corrosion resistance and intergranular corrosion of the austenitic stainless steel X5Cr Ni18-10 were tested on the base metal, heat affected zone and weld metal. Testing of pitting corrosion was performed by the potentiodynamic polarization method, while testing of intergranular corrosion was performed by the method of electrochemical potentiokinetic reactivation with double loop. The base metal was completely resistant to intergranular corrosion, while the heat affected zone showed a slight susceptibility to intergranular corrosion. Indicators of pitting corrosion resistance for the weld metal and the base metal were very similar, but their values are significantly higher than the values for the heat affected zone. This was caused by reduction of the chromium concentration in the grain boundary areas in the heat affected zone, even though the carbon content in the examined stainless steel is low (0.04 wt. % C.

Métodos para predição de bitter pit em maçãs 'Fuji' e 'Braeburn' Methods for bitter pit prediction in Fuji and Braeburn apples

Directory of Open Access Journals (Sweden)

Ivan Sestari

2009-07-01

.500nL L-1 ethephon solution plus 0.01% Tween-20. Four replications of 25 fruits of each orchard were stored on controlled atmosphere (CA during five months plus 12 days at 20°C in order to assess the real bitter pit occurrence. Both methods showed incidence and severity similar to real bitter pit occurrence after storage for both cultivars sampled 20 days before harvest. On the other hand, none method was able to predict the incidence of bitter pit after CA storage for fruits sampled at commercial harvest. The magnesium infiltration and immersion of fruits on ethephon only are efficient to predict bitter pit incidence on fruits when sampled 20 days before commercial harvest.

Tailoring Grain Storage Reserves for a Healthier Rice Diet and its Comparative Status with Other Cereals.

Science.gov (United States)

Butardo, Vito M; Sreenivasulu, Nese

2016-01-01

A global rise of diet-related noncommunicable diseases calls for a focus on diet-based nutritional intervention across the entire socioeconomic consumer spectrum. We review recent reports in the area of healthier rice aimed at developing rice grains with improved dietary fiber compositions (increased amounts of nonstarch polysaccharides and resistant starch), and less digestible starch (higher amylose and phospholipid complex in the endosperm) resulting in reduced glycemic impact upon grain consumption. We furthermore elaborate on the interconnections of elevated amounts of protein and a balanced composition of essential amino acids. The importance of a nutritious aleurone layer and its role in lipid storage and micronutrient composition is discussed briefly in the context of brown rice benefits. We identify gene targets for precision breeding that will facilitate the production of rice grains and rice-based products to mitigate the impact of nutrition-related preventable diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Numerical modelling of the groundwater inflow to an advancing open pit mine: Kolahdarvazeh pit, Central Iran.

Science.gov (United States)

Bahrami, Saeed; Doulati Ardejani, Faramarz; Aslani, Soheyla; Baafi, Ernest

2014-12-01

The groundwater inflow into a mine during its life and after ceasing operations is one of the most important concerns of the mining industry. This paper presents a hydrogeological assessment of the Irankuh Zn-Pb mine at 20 km south of Esfahan and 1 km northeast of Abnil in west-Central Iran. During mine excavation, the upper impervious bed of a confined aquifer was broken and water at high-pressure flowed into an open pit mine associated with the Kolahdarvazeh deposit. The inflow rates were 6.7 and 1.4 m(3)/s at the maximum and minimum quantities, respectively. Permeability, storage coefficient, thickness and initial head of the fully saturated confined aquifer were 3.5 × 10(-4) m/s, 0.2, 30 m and 60 m, respectively. The hydraulic heads as a function of time were monitored at four observation wells in the vicinity of the pit over 19 weeks and at an observation well near a test well over 21 h. In addition, by measuring the rate of pumping out from the pit sump, at a constant head (usually equal to height of the pit floor), the real inflow rates to the pit were monitored. The main innovations of this work were to make comparison between numerical modelling using a finite element software called SEEP/W and actual data related to inflow and extend the applicability of the numerical model. This model was further used to estimate the hydraulic heads at the observation wells around the pit over 19 weeks during mining operations. Data from a pump-out test and observation wells were used for model calibration and verification. In order to evaluate the model efficiency, the modelling results of inflow quantity and hydraulic heads were compared to those from analytical solutions, as well as the field data. The mean percent error in relation to field data for the inflow quantity was 0.108. It varied between 1.16 and 1.46 for hydraulic head predictions, which are much lower values than the mean percent errors resulted from the analytical solutions (from 1.8 to 5

Effect of gamma irradiation on bitter pit of apple fruits (Malus Domestica Borkh)

International Nuclear Information System (INIS)

Al-Bachir, M.; Farah, S.

2000-12-01

Tow varieties of apple fruits Golden and Starking were irradiated with 0, 0.5, 1.0, 1.5 kGy and with 0, 1.0, 1.5 kGy respectively. Irradiated and unirradiated fruits were stored at 1 to 2 centigrade and relative humidity of 80 to 90%. Fruit quality (firmness, skin thickness and bitter pit) and juice characteristics (moisture, ash, carbohydrates, organic acids, Ph, and viscosity), were determined during storage periods (0, 3 and 6 months). The used doses of gamma irradiation significantly decreased the percentage and intensity of bitter pit. Irradiated fruits were softer immediately after irradiation and through storage periods, there were no differences in firmness between irradiated and unirradiated fruits. Gamma irradiation increased the thickness of skin in Golden fruits and decreased it in Starking. Juice production from both varieties immediately after irradiation was not affected by gamma irradiation. However the juice produced from irradiated fruits had higher organic acids (citric and malic acids), viscosity and Ph values than the control. (author)

A probability distribution model of tooth pits for evaluating time-varying mesh stiffness of pitting gears

Science.gov (United States)

Lei, Yaguo; Liu, Zongyao; Wang, Delong; Yang, Xiao; Liu, Huan; Lin, Jing

2018-06-01

Tooth damage often causes a reduction in gear mesh stiffness. Thus time-varying mesh stiffness (TVMS) can be treated as an indication of gear health conditions. This study is devoted to investigating the mesh stiffness variations of a pair of external spur gears with tooth pitting, and proposes a new model for describing tooth pitting based on probability distribution. In the model, considering the appearance and development process of tooth pitting, we model the pitting on the surface of spur gear teeth as a series of pits with a uniform distribution in the direction of tooth width and a normal distribution in the direction of tooth height, respectively. In addition, four pitting degrees, from no pitting to severe pitting, are modeled. Finally, influences of tooth pitting on TVMS are analyzed in details and the proposed model is validated by comparing with a finite element model. The comparison results show that the proposed model is effective for the TVMS evaluations of pitting gears.

Final work plan : Phase I investigation of potential contamination at the former CCC/USDA grain storage facility in Savannah, Missouri.

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M.; Environmental Science Division

2007-10-12

From approximately 1949 until 1970, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility on federally owned property approximately 0.25 mi northwest of Savannah, Missouri. During this time, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the private grain storage industry to preserve grain in their facilities. In November 1998, carbon tetrachloride was detected in a private well (Morgan) roughly 50 ft south of the former CCC/USDA facility, as a result of state-wide screening of private wells near former CCC/USDA facilities, conducted in Missouri by the U.S. Environmental Protection Agency (EPA 1999). The 1998 and subsequent investigations by the EPA and the Missouri Department of Natural Resources (MoDNR) confirmed the presence of carbon tetrachloride in the Morgan well, as well as in a second well (on property currently occupied by the Missouri Department of Transportation [MoDOT]), approximately 400 ft east of the former CCC/USDA facility. Carbon tetrachloride concentrations in the Morgan well have ranged from the initial value of 29 {micro}g/L in 1998, up to a maximum of 61 {micro}g/L in 1999, and back down to 22 {micro}g/L in 2005. The carbon tetrachloride concentration in the MoDOT well in 2000 (the only time it was sampled) was 321 {micro}g/L. The concentrations for the two wells are above the EPA maximum contaminant level (MCL) of 5 {micro}g/L for carbon tetrachloride (EPA 1999; MoDNR 2000a,b). Because the observed contamination in the Morgan and MoDOT wells might be linked to the past use of carbon tetrachloride-based grain fumigants at its former grain storage facility, the CCC/USDA will conduct investigations to (1) characterize the source(s), extent, and factors controlling the subsurface distribution and movement of carbon tetrachloride at Savannah and (2) evaluate the health and environmental threats potentially posed by the contamination

Tank Riser Pit Decontamination System (Pit Viper) Return on Investment and Break-Even Analysis

International Nuclear Information System (INIS)

Young, Joan K.; Weimar, Mark R.; Balducci, Patrick J.; Fassbender, Linda L.; Hernandez, Melissa

2003-01-01

This study assessed the cost benefit of Pit Viper deployment for 80 tank farm pits between October 1, 2003 and September 30, 2012 under the technical baseline for applicable double-shell tank (DST) and single-shell tank (SST) projects. After this assessment had been completed, the U.S. Department of Energy (DOE) Richland Operations Office (RL) and Office of River Protection (ORP) published the Hanford Performance Management Plan (August 2003), which accelerated the schedule for SST retrieval. Then, DOE/CH2M HILL contract modification M064 (October 2002) and The Integrated Mission Acceleration Plan (March 2003) further accelerated SST retrieval and closure schedules. Twenty-six to 40 tanks must be retrieved by 2006. Thus the schedule for SST pit entries is accelerated and the number of SST pit entries is increased. This study estimates the return on investment (ROI) and the number of pits where Pit Viper deployment would break even or save money over current manual practices. The results of the analysis indicate a positive return on the federal investment for deployment of the Pit Viper provided it is used on a sufficient number of pits

F2AC: A Lightweight, Fine-Grained, and Flexible Access Control Scheme for File Storage in Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Wei Ren

2016-01-01

Full Text Available Current file storage service models for cloud servers assume that users either belong to single layer with different privileges or cannot authorize privileges iteratively. Thus, the access control is not fine-grained and flexible. Besides, most access control methods at cloud servers mainly rely on computationally intensive cryptographic algorithms and, especially, may not be able to support highly dynamic ad hoc groups with addition and removal of group members. In this paper, we propose a scheme called F2AC, which is a lightweight, fine-grained, and flexible access control scheme for file storage in mobile cloud computing. F2AC can not only achieve iterative authorization, authentication with tailored policies, and access control for dynamically changing accessing groups, but also provide access privilege transition and revocation. A new access control model called directed tree with linked leaf model is proposed for further implementations in data structures and algorithms. The extensive analysis is given for justifying the soundness and completeness of F2AC.

Influence of gamma radiation on oviposition and egg viability of Callosobruchus maculatus F. and grain loss in mungbean storage

International Nuclear Information System (INIS)

Dongre, T.K.; Rananavare, H.D.; Padwal Desai, S.R.

1997-01-01

Influence of gamma radiation on reproductive potential of Callosobruchus maculatus F. was studied by exposing them to 10, 30 and 50 Gy of radiation. Radiation at pupal stage was more effective in arresting egg laying and its further development. The dose of 50 Gy induced complete infertility in males when they were irradiated at pupal stage and only partial infertility was induced when irradiated at adult stage. In case of females whether irradiated at pupal or adult stage the dose of 50 Gy was sufficient to induce complete infertility. In order to assess the requirement of radiation doses for preventing the insect multiplication and subsequent damage in storage, mungbean samples with various developmental stages of insect were exposed to radiation at 50, 100 and 150 Gy. After three months of storage no grain damage was noticed when grains infested with different insect stages were irradiated with the dose of 100 or 150 Gy. (author)

Studies on the use of gamma rays in preservation and storage of african sorghum grains

International Nuclear Information System (INIS)

Botros, H.W.

1996-01-01

Grains are stored in large quantities all over the world and form the bases of human food supply. The amount of post harvest losses of food especially food grain is considered to be highest on be highest on the african continent,where preservation and storage are poorly managed. As a result, increasing numbers of less developed countries in africa are suffering from problems of hunger and malnutrition (Paster and Berck, 1993). One of the most important world cereal is sorghum, where it represents the fourth world cereal following wheat, rice and maize. It is an essential food in the drier parts of tropical africa, india and china. According to the FAO production yearbook (1992), about 22.25% of the total world production of sorghum grains is produced in africa, whereas, sudan produces 27.5% of the total african production . In the developed countries sorghum is used as a source of feed for birds, cattle, and sheep, but in the poor countries, as in african countries, the above uses are rare because sorghum is mainly used for human consumption.14 tab., 9 figs.,169 ref

PESTICIDES USE AMONG GRAIN MERCHANTS IN MUBI GRAIN ...

African Journals Online (AJOL)

AGROSEARCH UIL

pose the greatest threat to increased food production, storage and handling ... are to: assess pest control practices of grain merchants in Mubi markets with a .... This further cements the fact that multiple routes of contaminations are possible.

High moisture airtight storage of barley and triticale: Effect of moisture level and grain processing on nitrogen and phosphorus solubility

DEFF Research Database (Denmark)

Ton Nu, Mai Anh; Blaabjerg, Karoline; Labouriau, Rodrigo

2015-01-01

The aim of this study was to evaluate the effect of storage time, grain processing (whole vs. rolled) and the combination of phytase, xylanase, β-glucanase and protease on nitrogen (N) and phosphorus (P) solubility during high moisture airtight (HMA) storage of barley and triticale at various...... moisture levels (20, 23, 26 and 29% moisture) and to compare HMA storage of cereals with dry storage for 49 days. Dry stored barley and triticale (10 and 13% moisture, respectively) were kept in 10 L plastic buckets for 0 and 49 days. HMA stored cereals were kept in airtight bags (400 g per bag) at 15 °C......) in HMA storage at 29% moisture to a greater extent compared with dry storage (P levels increased P solubility (rolled barley, whole and rolled triticale) and N solubility (whole and rolled triticale) linearly and decreased Phytate P:Total P (rolled barley) linearly...

Open Pit Water Control Safety A Case Of Nchanga Open Pit Mine Zambia

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Silwamba C

2015-08-01

Full Text Available Abstract Mining in Chingola Zambia started underground in 1931 and was catastrophically flooded and closed. The present Nchanga Underground Mine NUG started in 1937. The Nchanga Open Pit NOP mine started in 1955 situated to the west of NUG and partially overlying it. Open pit water control safety operations in the Nchanga-Chingola area have successfully enabled the safe extraction of millions of tonnes of copper ore annually over the past 60 years from NUG mining as well as the NOP. At the start Nchanga mining license surface already had NUG and many watershed divides with the Nchanga and Chingola streams being the main streams feeding into Zambias second largest river Kafue river and 42 of the year was characterised by heavy rains ranging between 800mm to 1300mm per annum. In this paper the presence of very significant amounts of seasonal rain and subsurface water in the mining area was identified as both a curse and a blessing. An excess in seasonal rain and subsurface water would disrupt both open pit and underground mining operations. In order for NOP to be operated successfully stable and free from flooding coping water management tactics were adopted from 1955 to 2015 including 1. Underground mine pump chamber pumping system 2. Piezometer instrumented boreholes 3. Underground mine 1500-ft sub-haulage east borehole dewatering beneath the open pit 4. Nchanga and Chingola stream diversionary tunnel and open drains 5. Nchanga stream causeway and embankment dam in the Matero School Golf Club area 6. Pit perimeter borehole pumping 7. Outer and inner pit perimeter drains and bund walls 8. In-pit ramp side drains 9. In-pit sub-horizontal borehole geo-drains and water and 10. Pit bottom sump pumps. Application of grout curtains along the Vistula River Poland was noted as a possibility in the right circumstances although it had never been used at Nchanga Open Pit. An additional conclusion was that forward health safety and environmental end

Storage device of reactor fuel

International Nuclear Information System (INIS)

Nakamura, Masaaki.

1997-01-01

The present invention concerns storage of spent fuels and provides a storage device capable of securing container-cells in shielding water by remote handling and moving and securing the container-cells easily. Namely, a horizontal support plate has a plurality of openings formed in a lattice like form and is disposed in a pit filled with water. The container-cell has a rectangular cross section, and is inserted and disposed vertically in the openings. Securing members are put between the container-cells above the horizontal support plate, and constituted so as to be expandable from above by remote handling. The securing member is preferably comprised of a vertical screw member and an expandable urging member. Since securing members for securing the container-cells for incorporating reactor fuels are disposed to the horizontal support plate controllable from above by the remote handling, fuel storage device can be disposed without entering into a radiation atmosphere. The container-cells can be settled and exchanged easily after starting of the use of a fuel pit. (I.S.)

SEM Characterization of Extinguished Grains from Plasma-Ignited M30 Charges

Science.gov (United States)

Kinkennon, A.; Birk, A.; DelGuercio, M.; Kaste, P.; Lieb, R.; Newberry, J.; Pesce-Rodriguez, R.; Schroeder, M.

2000-01-01

M30 propellant grains that had been ignited in interrupted closed bomb experiments were characterize by scanning electron microscopy (SEM). Previous chemical analysis of extinguished grains had given no indications of plasma-propellant chemical interactions that could explain the increased burning rates that had been previously observed in full-pressure closed bomb experiments. (This does not mean that there is no unique chemistry occurring with plasma ignition. It may occur very early in the ignition event and then become obscured by the burning chemistry.) In this work, SEM was used to look at grain morphologies to determine if there were increases in the surface areas of the plasma-ignited grains which would contribute to the apparent increase in the burning rate. Charges were made using 30 propellant grains (approximately 32 grams) stacked in two tiers and in two concentric circles around a plastic straw. Each grain was notched so that, when the grains were expelled from the bomb during extinguishment, it could be determined in which tier and which circle each grain was originally packed. Charges were ignited in a closed bomb by either a nickel wire/Mylar-capillary plasma or black powder. The bomb contained a blowout disk that ruptured when the pressure reached 35 MPa, and the propellant was vented into a collection chamber packed with polyurethane foam. SEM analysis of the grains fired with a conventional black powder igniter showed no signs of unusual burning characteristics. The surfaces seemed to be evenly burned on the exteriors of the grains and in the perforations. Grains that had been subjected to plasma ignition, however, had pits, gouges, chasms, and cracks in the surfaces. The sides of the grains closest to the plasma had the greatest amount of damage, but even surfaces facing the outer wall of the bomb had small pits. The perforations contained gouges and abnormally burned regions (wormholes) that extended into the web. The SEM photos indicated that

Report of test results at USSO grain elevator - 31150 Lespinasse (France). Storage in tight cells under controlled atmosphere

Energy Technology Data Exchange (ETDEWEB)

1989-12-31

Experimental tests have been conducted with a new storage system for grains: disinsectization of weevil infested wheat through carbon dioxide injection and phosphine (PH3) injection; study of the behaviour of moist harvested sunflowers, stored under carbon dioxide before drying; study of the behaviour of very humid harvested corn, stored in confined atmosphere (without addition of CO2) before drying.

Fast Track Characterization of Highly Radioactive Waste Pits Combining Off-the-Shelf Robotics with Innovative Investigation Protocols

International Nuclear Information System (INIS)

Chabeuf, Jean-Michel; Boya, Didier

2008-01-01

The investigation and characterization of radioactive waste pits and effluent storage tanks represents a substantial and challenging step in the overall decommissioning programme launched by AREVA NC in 1998 on the site of Marcoule on behalf of the French Atomic Energy commission. Physical ,radiological and regulatory constraints, combined with a tight schedule, have lead our teams to use proven conventional instrumentation and robotics in innovative configurations . One such investigation, conducted on a particularly challenging radioactive effluent storage pit, is described below. The 'H' pit is a stainless steel clad concrete cavity, located in the second basement of the de-cladding building of Marcoule site. It was used for forty years as buffer storage for high activity effluents and has a length of 5 meters, a width of 3 meters , a height of 2.5 meters, and is topped by lead plates over 5 cm thick and The bottom of the cavity is covered with a layer of mud containing mainly graphite, diatoms and resins. The mud level ranges from about 20 centimeters to over 50 centimeters. The overall mud volume is around 2.4 cubic meters. Ambient dose rates above the lead plates exceed 10 mSv/h. The main purpose of our investigation was to characterize the muds for future recovery and conditioning prior to decontaminating the pit. The history of the pit together with the varying mud altimetry lead us to believe that sedimentation had probably occurred throughout the years. We thus decided to combine dose rate measurements using IF104 probes, gamma spectroscopy with CdTe probes and sample collections at different depths to ensure the representativeness and full characterization of the muds. Poor access, ambient dose rates have lead us to conceive a robotic arm, mounted on an shaft which can be modified to fit a wide range of pits and tanks. Custom built robotic tools with maximum manoeuvrability generally involve costs and delays far exceeding our purposes. SIT, a French

NELL-1 increases pre-osteoblast mineralization using both phosphate transporter Pit1 and Pit2

Energy Technology Data Exchange (ETDEWEB)

Cowan, Catherine M. [Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza,7523 Boelter Hall, Los Angeles, CA 90095 (United States); Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Zhang, Xinli; James, Aaron W.; Mari Kim, T.; Sun, Nichole [Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Wu, Benjamin [Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza,7523 Boelter Hall, Los Angeles, CA 90095 (United States); Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Ting, Kang [Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Soo, Chia, E-mail: bsoo@ucla.edu [UCLA and Orthopaedic Hospital Department of Orthopaedic Surgery and the Orthopaedic, Hospital Research Center, University of California, Los Angeles, 2641 Charles E. Young Dr. South, Los Angeles, CA 90095 (United States)

2012-06-08

Highlights: Black-Right-Pointing-Pointer NELL-1 accelerates extracellular matrix mineralization in MC3T3-E1 pre-osteoblasts. Black-Right-Pointing-Pointer NELL-1 significantly increases intracellular inorganic phosphate levels. Black-Right-Pointing-Pointer NELL-1 positively regulates osteogenesis but not proliferation in MC3T3-E1 cells. Black-Right-Pointing-Pointer NELL-1 regulates inorganic phosphate transporter activity. -- Abstract: NELL-1 is a potent osteoinductive molecule that enhances bone formation in multiple animal models through currently unidentified pathways. In the present manuscript, we hypothesized that NELL-1 may regulate osteogenic differentiation accompanied by alteration of inorganic phosphate (Pi) entry into the osteoblast via sodium dependent phosphate (NaPi) transporters. To determine this, MC3T3-E1 pre-osteoblasts were cultured in the presence of recombinant human (rh)NELL-1 or rhBMP-2. Analysis was performed for intracellular Pi levels through malachite green staining, Pit-1 and Pit-2 expression, and forced upregulation of Pit-1 and Pit-2. Results showed rhNELL-1 to increase MC3T3-E1 matrix mineralization and Pi influx associated with activation of both Pit-1 and Pit-2 channels, with significantly increased Pit-2 production. In contrast, Pi transport elicited by rhBMP-2 showed to be associated with increased Pit-1 production only. Next, neutralizing antibodies against Pit-1 and Pit-2 completely abrogated the Pi influx effect of rhNELL-1, suggesting rhNELL-1 is dependent on both transporters. These results identify one potential mechanism of action for rhNELL-1 induced osteogenesis and highlight a fundamental difference between NELL-1 and BMP-2 signaling.

NELL-1 increases pre-osteoblast mineralization using both phosphate transporter Pit1 and Pit2

International Nuclear Information System (INIS)

Cowan, Catherine M.; Zhang, Xinli; James, Aaron W.; Mari Kim, T.; Sun, Nichole; Wu, Benjamin; Ting, Kang; Soo, Chia

2012-01-01

Highlights: ► NELL-1 accelerates extracellular matrix mineralization in MC3T3-E1 pre-osteoblasts. ► NELL-1 significantly increases intracellular inorganic phosphate levels. ► NELL-1 positively regulates osteogenesis but not proliferation in MC3T3-E1 cells. ► NELL-1 regulates inorganic phosphate transporter activity. -- Abstract: NELL-1 is a potent osteoinductive molecule that enhances bone formation in multiple animal models through currently unidentified pathways. In the present manuscript, we hypothesized that NELL-1 may regulate osteogenic differentiation accompanied by alteration of inorganic phosphate (Pi) entry into the osteoblast via sodium dependent phosphate (NaPi) transporters. To determine this, MC3T3-E1 pre-osteoblasts were cultured in the presence of recombinant human (rh)NELL-1 or rhBMP-2. Analysis was performed for intracellular Pi levels through malachite green staining, Pit-1 and Pit-2 expression, and forced upregulation of Pit-1 and Pit-2. Results showed rhNELL-1 to increase MC3T3-E1 matrix mineralization and Pi influx associated with activation of both Pit-1 and Pit-2 channels, with significantly increased Pit-2 production. In contrast, Pi transport elicited by rhBMP-2 showed to be associated with increased Pit-1 production only. Next, neutralizing antibodies against Pit-1 and Pit-2 completely abrogated the Pi influx effect of rhNELL-1, suggesting rhNELL-1 is dependent on both transporters. These results identify one potential mechanism of action for rhNELL-1 induced osteogenesis and highlight a fundamental difference between NELL-1 and BMP-2 signaling.

Single pit propagation on austenitic stainless steel

International Nuclear Information System (INIS)

Heurtault, Stephane

2016-01-01

The electrochemical characterization of metastable events such as pitting corrosion of stainless steel in chloride electrolyte remains complex because many individual processes may occur simultaneously on the alloy surface. To overcome these difficulties, an experimental setup, the flow micro-device, has been developed to achieve the initiation of a single pit and to propagate the single pit in three dimensions. In this work, we take advantage of such a device in order to revisit the pitting process on a 316L stainless steel in a chloride - sulphate bulk. In a first step, the time evolution of the pit geometry (depth, radius) and the chemical evolution of the pit solution investigated using in situ Raman spectroscopy have shown that the pit depth propagation depends on the formation of a metal chloride and sulphate gel in the pit solution, and is controlled by the metallic cations diffusion from the pit bottom to the pit mouth. The pit radius growth is defined by the initial surface de-passivation, by the presence of a pit cover and by the gel development in the solution. all of these phenomena are function of applied potential and chemical composition of the solution. In a last step, it was demonstrated that a critical chloride concentration is needed in order to maintain the pit propagation. This critical concentration slightly increases with the pit depth. From statistical analysis performed on identical experiments, a zone diagram showing the pit stability as a function of the chloride concentration and the pit dimensions was built. (author) [fr

Interacting Effects Induced by Two Neighboring Pits Considering Relative Position Parameters and Pit Depth

Directory of Open Access Journals (Sweden)

Yongfang Huang

2017-04-01

Full Text Available For pre-corroded aluminum alloy 7075-T6, the interacting effects of two neighboring pits on the stress concentration are comprehensively analyzed by considering various relative position parameters (inclination angle θ and dimensionless spacing parameter λ and pit depth (d with the finite element method. According to the severity of the stress concentration, the critical corrosion regions, bearing high susceptibility to fatigue damage, are determined for intersecting and adjacent pits, respectively. A straightforward approach is accordingly proposed to conservatively estimate the combined stress concentration factor induced by two neighboring pits, and a concrete application example is presented. It is found that for intersecting pits, the normalized stress concentration factor Ktnor increases with the increase of θ and λ and always reaches its maximum at θ = 90°, yet for adjacent pits, Ktnor decreases with the increase of λ and the maximum value appears at a slight asymmetric location. The simulations reveal that Ktnor follows a linear and an exponential relationship with the dimensionless depth parameter Rd for intersecting and adjacent cases, respectively.

Ochratoxin A and citrinin loads in stored wheat grains: impact of grain dust and possible prediction using ergosterol measurement.

Science.gov (United States)

Tangni, E K; Pussemier, L

2006-02-01

Crop storage should be carried out under hygienic conditions to ensure safe products, but sometimes grain dust which has settled from previous storage may be left over and incorporated to the following stored grains. This paper describes the results obtained using a lab model developed in order to assess the impact of grain dust incorporation for its direct contribution as a contaminant but also as an inoculum in stored wheat. Settled grain dust (4 samples) released from Belgian grain storages were collected and analysed by HPLC for ergosterol, ochratoxin A (OTA) and citrinin (CIT) content. For OTA and for ergosterol, there was a high degree of variability in concentrations found in the dust samples (from 17.3-318 ng g(-1) and from 39-823 microg g(-1), respectively) whilst for CIT, the range was less significant (from 137-344 ng g(-1)). Incorporation of grain dust into wheat storage contributed to an increase in the concentrations of mycotoxins in the stored grain. Dust acts as a contaminant and as an inoculum. According to these two ways, patterns of mycotoxin generation vary with the nature of the mycotoxin, the mycotoxigenic potential of dust and the water activity of the wheat. OTA and CIT showed a very versatile image when considering the amounts of toxins produced under the selected experimental conditions. The development of a robust tool to forecast the mycotoxigenicity of dust was based on the determination of ergosterol content as a general marker of fungal biomass. Present results suggest that this predictive tool would only be valid for predicting the contamination level of CIT and OTA at reasonable moisture content (14-20%). The potential risk of having highly contaminated batches from stock to stock may thus occur and this paper discusses possible pathways leading to OTA and CIT contamination either under wet or dry storage conditions. We therefore, recommend taking precautionary measures not only by controlling and maintaining moisture at a

Effect of Calcium Salt on Soft Rot, Bitter Pit and Physico-Chemical Properties of Stored Apples

International Nuclear Information System (INIS)

Jan, I.; Rab, A.; Sajid, M.; Iqbal, A.; Shinwari, Z. K.; Hamayun, M.

2016-01-01

Postharvest losses are one of the main problems in leading fruit producing countries. Therefore, an attempt has been made to decrease the postharvest losses during apple storage. To achieve this objective, fruits were dipped in 0, 3, 6 and 9 percent CaCl/sub 2/ solution for the period of 3, 6, 9 and 12 minutes and were stored for 150 days at 5 ± 1 C with 60-70 percent relative humidity. After the storage time, fruits were analysed for percent weight loss, total sugar, bitter pit incidence, soft rot, ascorbic acid and firmness. The ascorbic acid contents and firmness of the fruits significantly increased, when the fruits were dipped in 9% CaCl/sub 2/ solution as compared to control (dipped in water). Whereas, weight loss, total sugar, bitter pit and soft rot incidences were reduced with increased concentration of CaCl/sub 2/. The firmness of the fruits dipped for 3 minutes in a CaCl/sub 2/ solution was significantly lower in comparison to the fruits dipped for 12 minutes in a CaCl/sub 2/ solution. Likewise, the weight loss, bitter pit and the soft rot incidence reduced with increase in dipping duration in CaCl/sub 2/ solution from 3 minutes to 12 minutes. (author)

Surface monitoring for pitting evolution into uniform corrosion on Cu-Ni-Zn ternary alloy in alkaline chloride solution: ex-situ LCM and in-situ SECM

Science.gov (United States)

Kong, Decheng; Dong, Chaofang; Zheng, Zhaoran; Mao, Feixiong; Xu, Aoni; Ni, Xiaoqing; Man, Cheng; Yao, Jizheng; Xiao, Kui; Li, Xiaogang

2018-05-01

The evolution of the corrosion process on Cu-Ni-Zn alloy in alkaline chloride solution was investigated by in-situ scanning electrochemical microscopy, X-ray photoelectron spectroscopy, and ex-situ laser confocal microscopy, and the effects of ambient temperature and polarization time were also discussed. The results demonstrated a higher pitting nucleation rate and lower pit growth rate at low temperature. The ratio of pit depth to mouth diameter decreased with increasing pit volume and temperature, indicating that pits preferentially propagate in the horizontal direction rather than the vertical direction owing to the presence of corrosion products and deposited copper. The surface current was uniform and stabilized at approximately 2.2 nA during the passive stage, whereas the current increased after the pits were formed with the maximum approaching 3 nA. Increasing the temperature led to an increase in porous corrosion products (CuO, Zn(OH)2, and Ni(OH)2) and significantly increased the rate of transition from pitting to uniform corrosion. Dezincification corrosion was detected by energy dispersive spectrometry, and a mechanism for pitting transition into uniform corrosion induced by dezincification at the grain boundaries is proposed.

Final work plan : phase I investigation of potential contamination at the former CCC/USDA grain storage facility in Montgomery City, Missouri.

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M.; Environmental Science Division

2010-08-16

From September 1949 until September 1966, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) leased property at the southeastern end of Montgomery City, Missouri, for the operation of a grain storage facility. During this time, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the private grain storage industry to preserve grain in their facilities. In January 2000, carbon tetrachloride was detected in a soil sample (220 {micro}g/kg) and two soil gas samples (58 {micro}g/m{sup 3} and 550 {micro}g/m{sup 3}) collected at the former CCC/USDA facility, as a result of a pre-CERCLIS site screening investigation (SSI) performed by TN & Associates, Inc., on behalf of the U.S. Environmental Protection Agency (EPA), Region VII (MoDNR 2001). In June 2001, the Missouri Department of Natural Resources (MoDNR) conducted further sampling of the soils and groundwater at the former CCC/USDA facility as part of a preliminary assessment/site inspection (PA/SI). The MoDNR confirmed the presence of carbon tetrachloride (at a maximum identified concentration of 2,810 {micro}g/kg) and chloroform (maximum 82 {micro}g/kg) in the soils and also detected carbon tetrachloride and chloroform (42.2 {micro}g/L and 58.4 {micro}g/L, respectively) in a groundwater sample collected at the former facility (MoDNR 2001). The carbon tetrachloride levels identified in the soils and groundwater are above the default target level (DTL) values established by the MoDNR for this contaminant in soils of all types (79.6 {micro}g/kg) and in groundwater (5.0 {micro}g/L), as outlined in Missouri Risk-Based Corrective Action (MRBCA): Departmental Technical Guidance (MoDNR 2006a). The corresponding MRBCA DTL values for chloroform are 76.6 {micro}g/kg in soils of all types and 80 {micro}g/L in groundwater. Because the observed contamination at Montgomery City might be linked to the past use of carbon tetrachloride-based fumigants at its

Pits, rifts and slumps: the summit structure of Piton de la Fournaise

Science.gov (United States)

Carter, Adam; van Wyk de Vries, Benjamin; Kelfoun, Karim; Bachèlery, Patrick; Briole, Pierre

2007-06-01

A clear model of structures and associated stress fields of a volcano can provide a framework in which to study and monitor activity. We propose a volcano-tectonic model for the dynamics of the summit of Piton de la Fournaise (La Reunion Island, Indian Ocean). The summit contains two main pit crater structures (Dolomieu and Bory), two active rift zones, and a slumping eastern sector, all of which contribute to the actual fracture system. Dolomieu has developed over 100 years by sudden large collapse events and subsequent smaller drops that include terrace formation. Small intra-pit collapse scars and eruptive fissures are located along the southern floor of Dolomieu. The western pit wall of Dolomieu has a superficial inward dipping normal fault boundary connected to a deeper ring fault system. Outside Dolomieu, an oval extension zone containing sub-parallel pit-related fractures extends to a maximum distance of 225 m from the pit. At the summit the main trend for eruptive fissures is N80°, normal to the north south rift zone. The terraced structure of Dolomieu has been reproduced by analogue models with a roof to width ratio of approximately 1, suggesting an original magma chamber depth of about 1 km. Such a chamber may continue to act as a storage location today. The east flank has a convex concave profile and is bounded by strike-slip fractures that define a gravity slump. This zone is bound to the north by strike-slip fractures that may delineate a shear zone. The southern reciprocal shear zone is probably marked by an alignment of large scoria cones and is hidden by recent aa lavas. The slump head intersects Dolomieu pit and may slide on a hydrothermally altered layer known to be located at a depth of around 300 m. Our model has the summit activity controlled by the pit crater collapse structure, not the rifts. The rifts become important on the mid-flanks of the cone, away from pit-related fractures. On the east flank the superficial structures are controlled

Vacuum technologies developed for at-400A Type B transportation and storage package

International Nuclear Information System (INIS)

Franklin, K.W.; Cockrell, G.D.

1995-01-01

The AT-400A TYPE B transportation and storage container will be used at Pantex Plant for the transportation and interim storage of plutonium pits. The AT-400A was designed by a joint effort between Sandia National Labs, Los Alamos National Labs, Lawrence Livermore National Laboratory, and Mason and Hanger-Silas Mason Co., Inc. In order to meet the requirements for transportation and storage, five different vacuum technologies had to be developed. The goals of the various vacuum technologies were to verify the plutonium pit was sealed, perform the assembly verification leak check in accordance with ANSI N-14.5 and to provide a final inert gas backfill in the containment vessel. This paper will discuss the following five vacuum technologies: (1) Pit Leak Testing, (2) Containment Vessel Purge and Backfill with tracer gas, (3) Containment Vessel Leak Testing, (4) Containment Vessel Purge and Final Backfill, and (5) Leak Testing of the Containment Vessel Gas Transfer tube

Análise multivariada de atributos nutricionais associados ao "bitter pit" em maçãs 'Gala' Multivariate analysis of nutritional attributes associated with bitter pit in 'Gala' apples

Directory of Open Access Journals (Sweden)

Cassandro Vidal Talamini do Amarante

2006-05-01

Full Text Available O objetivo deste trabalho foi identificar atributos nutricionais, quantificados na polpa e na casca dos frutos, que melhor discriminam quanto à severidade de "bitter pit" em maçãs 'Gala'. Depois de quatro meses de armazenamento em atmosfera normal (0-1°C; 90-95% UR, os frutos foram separados em quatro lotes, de acordo com a severidade de incidência de "bitter pit": nula (nenhuma lesão por fruto, baixa (1-2 lesões por fruto, moderada (3-4 lesões por fruto e alta (5-13 lesões por fruto. Foram determinados os teores de Ca, Mg, K e N na casca e na polpa em frutos individuais (doze frutos de cada lote. A análise univariada mostrou que os frutos com sintomas de "bitter pit" apresentaram menor teor de Ca na casca e na polpa, maior teor de K na casca e maiores valores das relações K/Ca, Mg/Ca, N/Ca, (K+Mg/Ca e (K+Mg+N/Ca, tanto na casca como na polpa. Todavia, quando todos os atributos nutricionais avaliados na casca e na polpa foram submetidos à análise canônica discriminante (análise multivariada, a melhor discriminação entre frutos sem "bitter pit" e frutos com severidade de incidência de "bitter pit" de baixa a alta é obtida com a relação K/Ca na casca, seguido, em menor grau, pelas relações Mg/Ca e N/Ca na polpa.The objective of this work was to identify nutritional attributes, assessed in the flesh and skin tissues, that provide a better discrimination regarding bitter pit severity in 'Gala' apples. After four months in regular cold storage (0-1°C; 90-95% RH, fruits were segregated into four lots with different levels of bitter pit severity: null (none pit per fruit, low (1-2 pits per fruit, moderate (3-4 pits per fruit, and high (5-13 pits per fruit. Nutritional analysis (Ca, Mg, K and N in the skin and in the flesh tissues were performed on twelve individual fruits of each severity level. The univariate analysis showed that fruits with bitter pit symptoms had lower concentration of Ca in the skin and flesh tissues, a

Label-free proteome profiling reveals developmental-dependent patterns in young barley grains.

Science.gov (United States)

Kaspar-Schoenefeld, Stephanie; Merx, Kathleen; Jozefowicz, Anna Maria; Hartmann, Anja; Seiffert, Udo; Weschke, Winfriede; Matros, Andrea; Mock, Hans-Peter

2016-06-30

Due to its importance as a cereal crop worldwide, high interest in the determination of factors influencing barley grain quality exists. This study focusses on the elucidation of protein networks affecting early grain developmental processes. NanoLC-based separation coupled to label-free MS detection was applied to gain insights into biochemical processes during five different grain developmental phases (pre-storage until storage phase, 3days to 16days after flowering). Multivariate statistics revealed two distinct developmental patterns during the analysed grain developmental phases: proteins showed either highest abundance in the middle phase of development - in the transition phase - or at later developmental stages - within the storage phase. Verification of developmental patterns observed by proteomic analysis was done by applying hypothesis-driven approaches, namely Western Blot analysis and enzyme assays. High general metabolic activity of the grain with regard to protein synthesis, cell cycle regulation, defence against oxidative stress, and energy production via photosynthesis was observed in the transition phase. Proteins upregulated in the storage phase are related towards storage protein accumulation, and interestingly to the defence of storage reserves against pathogens. A mixed regulatory pattern for most enzymes detected in our study points to regulatory mechanisms at the level of protein isoforms. In-depth understanding of early grain developmental processes of cereal caryopses is of high importance as they influence final grain weight and quality. Our knowledge about these processes is still limited, especially on proteome level. To identify key mechanisms in early barley grain development, a label-free data-independent proteomics acquisition approach has been applied. Our data clearly show, that proteins either exhibit highest expression during cellularization and the switch to the storage phase (transition phase, 5-7 DAF), or during storage

Remote Sensing Insights into Storage Capacities among Plains Village Horticulturalists

Science.gov (United States)

Wiewel, Adam S.

Maize was a fundamental component of the diet and economy of Middle Missouri Plains Village groups, sedentary farmers with settlements along the Missouri River during the last millennia. More than a century of study has contributed to our understanding of agricultural production among these peoples, but little effort has been made to consider temporal variation in production. Such an understanding is crucial to examining changes that occurred before and after the arrival of colonists and their trade goods in the seventeenth century. Plains archaeologists have suggested that the storage capacity of Middle Missouri villages increased during the sixteenth through the eighteenth centuries. In fact, the number and size of subterranean storage pits, ubiquitous features within most settlements, are thought to have grown during these centuries, which reflects greater agricultural production. To further examine changes in production and storage capacity during this centuries-long period, I combine information from historical documents, excavations, and geophysical investigations. At Huff Village, a fifteenth-century community, excavations and magnetic gradiometry surveys reveal the size and distribution of storage pits. Their number and average volume suggest the villagers grew immense amounts of food and contributed to widespread intertribal trade. Furthermore, storage pit excavation data from 20 regional sites, dating from the thirteenth to the nineteenth century, indicate pit volumes increased through the seventeenth century. A sharp decrease subsequently occurred during the eighteenth century due to epidemic disease. However, mean pit volumes were significantly larger during the nineteenth century, evidence of the resilience of Mandans, Hidatsas, and Arikaras and the continued significance of maize. In fact, historical documents and remote sensing data suggest the Mandans and Arikaras, successive occupants of an earthlodge village near the American Fur Company's Fort

Identificação pré-colheita do risco de ocorrência de "bitter pit" em maçãs 'gala' por meio de infiltração com magnésio e análise dos teores de cálcio e nitrogênio nos frutos Preharvest identification of bitter pit risk in 'gala' apples by fruit infiltration with magnesium and analysis of fruit contents of calcium and nitrogen

Directory of Open Access Journals (Sweden)

Cassandro Vidal Talamini do Amarante

2010-03-01

Full Text Available O "bitter pit" é um distúrbio fisiológico pós-colheita em maçãs, ocasionado pela deficiência de Ca e agravado pela presença de elevados níveis de Mg, N e K nos frutos. O objetivo deste trabalho foi avaliar a viabilidade prática da infiltração de maçãs 'Gala' com Mg, visando a avaliar, em pré-colheita, o risco de ocorrência de "bitter pit" durante o armazenamento refrigerado, bem como a identificar os atributos minerais do fruto associados à ocorrência do distúrbio. Em 50 talhões de pomares localizados no município de Fraiburgo-SC, foram coletadas amostras de 25 frutos / talhão, cerca de 20 dias antes do início da colheita comercial, sendo os mesmos infiltrados a vácuo com Mg e avaliados quanto à incidência (% e severidade (manchas / fruto de "bitter pit". Nos mesmos talhões, na maturação comercial, foram coletadas amostras de 120 frutos / talhão, sendo que 100 frutos foram armazenados em câmara fria convencional durante quatro meses (0 ± 0,5ºC e 90-95% UR, e 20 frutos foram utilizados para a análise mineral (teores de Ca, Mg, K e N. Cinco dias após a remoção da câmara fria, os frutos foram avaliados quanto à incidência (% e severidade (manchas / fruto de "bitter pit". Houve correlação linear altamente significativa (r² = 0,69; pBitter pit is a postharvest physiological disorder in apples, related to Ca deficiency, and aggravated by high levels of Mg, N, and K in the fruits. This work was carried out to assess the practical viability of 'Gala' apples infiltration with Mg, for preharvest identification of bitter pit risk during cold storage, as well as, to identify the mineral attributes associated with the occurrence of the disorder. Fruits were sampled in 50 plots of apple orchards located in Fraiburgo, SC (Southern Brazil. Samples of 25 fruits / plot were harvested about 20 days before commercial harvesting, and then vacuum infiltrated with Mg and assessed for incidence (% and severity (pits / fruit of

Flume Experiments on the Influence of Salmon Spawning Density on Grain Stability and Bedload Transport in Gravel-bed Streams

Science.gov (United States)

Buxton, T. H.

2015-12-01

Salmon spawning in streams involves the female salmon digging a pit in the bed where she deposits eggs for fertilization before covering them with gravel excavated from the next pit upstream. Sequences of pit excavation and filling winnow fines, loosen sediment, and move bed material into a tailspill mound resembling the shape of a dune. Research suggests salmonid nests (redds) destabilize streambeds by reducing friction between loosened grains and converging flow that elevates shear stress on redd topography. However, bed stability may be enhanced by form drag from redds in clusters that lower shear stress on the granular bed, but this effect will vary with the proportion of the bed surface that is occupied by redds (P). I used simulated redds and water-worked ("unspawned") beds in a laboratory flume to evaluate these competing influences on grain stability and bedload transport rates with P=0.12, 0.34, and 0.41. Results indicate that competence (largest-grain) and reference transport rate estimates of critical conditions for particle entrainment inversely relate to P. Bedload transport increased as exponential functions of P and excess boundary shear stress. Therefore, redd form drag did not overcome the destabilizing effects of spawning. Instead, grain mobility and bedload transport increased with P because larger areas of the bed were composed of relatively loose, unstable grains and redd topography that experienced elevated shear stress. Consequently, the presence of redds in fish-bearing streams likely reduces the effects of sedimentation from landscape disturbance on stream habitats that salmon use for reproduction.

Effect of Aging on Precipitation Behavior and Pitting Corrosion Resistance of SAF2906 Super Duplex Stainless Steel

Science.gov (United States)

Li, Jianchun; Li, Guoping; Liang, Wei; Han, Peide; Wang, Hongxia

2017-09-01

The effect of aging temperature and holding time on the precipitation of secondary phases and pitting corrosion resistance of SAF2906 super duplex stainless steel was examined. Chromium nitride and σ phase were observed to preferentially precipitate at the ferrite/austenite interface. An amount of nitrides was also observed within the ferrite grain. The precipitation of chromium nitride occurred before the σ phase. The increase in aging temperature and holding time did not affect the concentration of the nitrides but increased the area fraction of the σ phase at a faster rate. The Cr2N precipitation in SAF2906 is more evident than that of the other duplex stainless steels. The variation tendency of the precipitation concentrations is primarily consistent with the prediction results of Thermo-Calc software. The electrochemical results showed that Cr2N and σ phase significantly reduced the pitting potential. Scanning electron microscope observations revealed that pits appear mainly in regions adjacent to sigma phase and Cr2N.

Corrosion in ICPP fuel storage basins

International Nuclear Information System (INIS)

Dirk, W.J.

1993-09-01

The Idaho Chemical Processing Plant currently stores irradiated nuclear fuel in fuel storage basins. Historically, fuel has been stored for over 30 years. During the 1970's, an algae problem occurred which required higher levels of chemical treatment of the basin water to maintain visibility for fuel storage operations. This treatment led to higher levels of chlorides than seen previously which cause increased corrosion of aluminum and carbon steel, but has had little effect on the stainless steel in the basin. Corrosion measurements of select aluminum fuel storage cans, aluminum fuel storage buckets, and operational support equipment have been completed. Aluminum has exhibited good general corrosion rates, but has shown accelerated preferential attack in the form of pitting. Hot dipped zinc coated carbon steel, which has been in the basin for approximately 40 years, has shown a general corrosion rate of 4 mpy, and there is evidence of large shallow pits on the surface. A welded Type 304 stainless steel corrosion coupon has shown no attack after 13 years exposure. Galvanic couples between carbon steel welded to Type 304 stainless steel occur in fuel storage yokes exposed to the basin water. These welded couples have shown galvanic attack as well as hot weld cracking and intergranular cracking. The intergranular stress corrosion cracking is attributed to crevices formed during fabrication which allowed chlorides to concentrate

Evaluation of a potentially probiotic non-dairy beverage developed with honey and kefir grains: Fermentation kinetics and storage study.

Science.gov (United States)

Fiorda, Fernanda A; de Melo Pereira, Gilberto V; Thomaz-Soccol, Vanete; Rakshit, Sudip K; Soccol, Carlos R

2016-12-01

The aim of this work was to study the fermentation process of honey with kefir grains through a comprehensive understanding of its rheological properties, probiotic cell viability, instrumental color parameters and kinetic aspects in a batch bioreactor and during storage. The results showed that kefir grains were well adapted to bioreactor conditions, reaching high levels of cell viability (over 10 6 CFU mL -1 for total yeast and bacteria), phenolic compounds content (190 GAE/100 g) and acidification after 24 h of fermentation at 30 ℃. Colorimetric analysis showed that lightness (L*) and redness (a*) remained constant, while yellowness intensities (b*) decreased during fermentation time. After 35 days of storage, honey kefir beverage maintained its chemical characteristics and microbial viability as required to be classified as a probiotic product. The Ostwald-de-Waele (R 2  ≥ 0.98) and Herschel-Bulkley (R 2  ≥ 0.99) models can be used to predict the behavior of honey kefir beverage. The parameters analyzed in this study should be taken into account for industrial production of this novel non-dairy beverage. © The Author(s) 2016.

Chemical Composition and Insecticidal Activity of the Essential Oil of Illicium pachyphyllum Fruits against Two Grain Storage Insects

OpenAIRE

Liu, Peng; Liu, Xin-Chao; Dong, Hui-Wen; Liu, Zhi-Long; Du, Shu-Shan; Deng, Zhi-Wei

2012-01-01

The aim of this research was to determine chemical composition and insecticidal activity of the essential oil of Illicium pachyphyllum fruits against two grain storage insects, Sitophilus zeamais and Tribolium castaneum, and to isolate any insecticidal constituents from the essential oil. The essential oil of I. pachyphyllum fruits was obtained by hydrodistillation and analyzed by GC-MS. A total of 36 components of the essential oil were identified, with the principal compounds in the essenti...

Baseline Risk Assessment for the F-Area Burning/Rubble Pits and Rubble Pit

Energy Technology Data Exchange (ETDEWEB)

Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

1996-03-01

This document provides an overview of the Savannah River Site (SRS) and a description of the F-Area Burning/Rubble Pits (BRPs) and Rubble Pit (RP) unit. It also describes the objectives and scope of the baseline risk assessment (BRA).

Burn Pit Emissions Exposure and Respiratory and Cardiovascular Conditions Among Airborne Hazards and Open Burn Pit Registry Participants.

Science.gov (United States)

Liu, Jason; Lezama, Nicholas; Gasper, Joseph; Kawata, Jennifer; Morley, Sybil; Helmer, Drew; Ciminera, Paul

2016-07-01

The aim of this study was to determine how burn pit emissions exposure is associated with the incidence of respiratory and cardiovascular conditions. We examined the associations between assumed geographic and self-reported burn pit emissions exposure and respiratory and cardiovascular outcomes in participants of the Airborne Hazards and Open Burn Pit Registry. We found significant dose-response associations for higher risk of self-reported emphysema, chronic bronchitis, or chronic obstructive pulmonary disease with increased days of deployment within 2 miles of selected burn pits (P-trend = 0.01) and self-reported burn pit smoke exposure (P-trend = 0.0005). We found associations between burn pit emissions exposure and higher incidence of post-deployment self-reported respiratory and cardiovascular conditions, but these findings should be interpreted with caution because the surrogate measurements of burn pit emissions exposure in this analysis may not reflect individual exposure levels.

Oil sands mine pit wall design and performance at Syncrude

Energy Technology Data Exchange (ETDEWEB)

Cameron, R.; Danku, M; Purhar, G. [Syncrude Canada Ltd., Fort McMurray, AB (Canada)

2008-07-01

This study conducted slope stability analyses in order to compare pit performance at an oil sands mine with results from computerized simulations using conventionally known soil parameters. Ranges included fully-drained to fully-saturated piezometric conditions; full-peak strength conditions; fully-softened peak conditions; residual shear strength conditions; and undrained shear strength considerations. Pit wall designs were reviewed and a history of marine clay layers at the mine was presented. Assumed overburden fall-down limits were considered. Shovel overburden slope angles were calculated. An analysis of the review suggested that steeper pit walls provide less room for error and have a higher rate of failures. Incised pleistocene channels, joint and fracture areas as well as higher piezometric level areas also impacted on slope performance. Failed areas influenced ore volumes and led to productivity reductions below 50 per cent. It was concluded that the overburden portions of the oil sands mine ranged between 4H:1V to 5H:1V due to haul roads and the timing of top-bench pushbacks. Future plans for the mine must consider ore inventories, haul road requirements; running surface requirements; and ramping accesses. Future slopes at the oil sands mine will be buttressed with overburden and tailings storage areas, while longer-term slopes will be flattened. 6 refs., 2 tabs., 11 figs.

Corrosion surveillance in spent fuel storage pools

International Nuclear Information System (INIS)

Howell, J.P.

1996-01-01

In mid-1991, corrosion of aluminum-clad spent nuclear fuel was observed in the light-water filled basins at the Savannah River site. A corrosion surveillance program was initiated in the P, K, L-Reactor basins and in the Receiving Basin for Offsite Fuels (RBOF). This program verified the aggressive nature of the pitting corrosion and provided recommendations for changes in basin operations to permit extended longer term interim storage. The changes were implemented during 1994--1996 and have resulted in significantly improved basin water quality with conductivity in the 1--3 microS/cm range. Under these improved conditions, no new pitting has been observed over the last three years. This paper describes the corrosion surveillance program at SRS and what has been learned about the corrosion of aluminum-clad in spent fuel storage pools

COGEMA experience on retrieving and conditioning solid radwaste previously stored in pits. The La Hague North-West pit case

International Nuclear Information System (INIS)

Bodin, F.; Alexandre, D.; Fournier, P.

1999-01-01

Short lived, low and medium level waste called 'technological waste' produced by the La Hague Reprocessing Plant have been stored in the La Hague North-West concrete-lined pits until implementation at ANDRA's Centre de Stockage de la Manche (CSM). COGEMA decided to retrieve and condition 11,000 m 3 of humid solid radwaste, stored in bulk in pits. On account of the variety of radwaste kinds, retrieving and conditioning operations represented real challenge. One goal of these operations was to ensure that the work was performed in complete safety towards environment with optimum containment and with the best radiation protection for the personnel involved. COGEMA decided to split the work into two phases. The feedback from the first phase was very helpful to the second phase. This report describes the experience gained from February 1990 to December 1998, taking into account radwaste and integrated dose rate results conditioning such waste. The procedures and means used and improved by COGEMA to comply with ANDRA's storage standards and the ever-decreasing financial costs generated by the workers, allowed to retrieve and condition 11,000 m 3 of old solid radwaste with competitive costs and in complete safety and protection of the environment. (author)

Preliminary study of acoustic emission (ae) noise signal identification for crude oil storage tank

International Nuclear Information System (INIS)

Nurul Ain Ahmad Latif; Shukri Mohd

2008-08-01

This preliminary work was carried out to simulate the Acoustic Emission (AE) signal contributed by pitting corrosion, and noise signal from environment during crude oil storage tanks monitoring. The purpose of this study is to prove that acoustic emission (AE) could be used to detect the formation of pitting corrosion in the crude oil storage tank and differentiated it from other sources of noise signal. In this study, the pitting corrosion was simulated by inducing low voltage and low amperage current onto the crude oil storage tank material (ASTM 516 G 70). Water drop, air blow and surface rubbing were applied onto the specimen surface. To simulate the noise signal produce by rain fall, wind blow and other sources of noise during AE crude oil storage tanks monitoring. AE sensor was attached onto the other surface of specimen to acquire all of these AE signals which then has send to AE DiSP 24 data acquisition system for signal conditioning. AE win software has been used to analyse this entire signal. It is found that, simulated pitting corrosion could be detected by AE system and differentiated from other sources of noise by using amplitude analysis. From the amplitude analysis is shown that 20-30 dB is the range amplitude for the blow test, 50-60 dB for surface rubbing test and over than 60 dB for water drop test. (Author)

Burning/Rubble Pits: Environmental information document

International Nuclear Information System (INIS)

Huber, L.A.; Johnson, W.F.; Marine, I.W.

1987-03-01

The Burning/Rubble Pits, located near each of the major operating areas at the Savannah River Plant (SRP), began collecting burnable waste in 1951. The waste was incinerated monthly. All Burning/Rubble Pits are currently closed except for Burning/Rubble Pit 131-1R, which has not been backfilled but is inactive. No soil cores from the Burning/Rubble Pits have been analyzed. There are four groundwater monitoring wells located around each of the pits, which have been sampled quarterly since 1984. The closure options considered for the Burning/Rubble Pits are waste removal and closure, no waste removal and closure, and no action. Modeling calculations were made to determine the risks to human population for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated. An evaluation of the environmental impacts from the Burning/Rubble Pits indicates that the relative risks to human health and ecosystems for the postulated closure options are low. The ecological assessment shows that the effects of any closure activities on river water quality and wildlife would be insignificant. The cost estimates show the waste removal and closure option to be the most expensive for all of the pits. 38 refs., 35 figs., 47 tabs

Effect of Storage Methods and Period on the Physiological and Nutrient Components of Livingstone Potato (Plectranthus esculentus in Abia State, Nigeria

Directory of Open Access Journals (Sweden)

Ezeocha Chinelo Vanessa

2017-02-01

Full Text Available Livingstone potato production in Nigeria is faced with the challenge of high postharvest losses. The aim of this study was to assess the effect of some storage methods on the physiological and nutritional quality of livingstone potato. Potatoes were separated and stored using eight different methods: potatoes stored in3x3x3 ft pits and covered with sand under the shade (T1, potatoes stored in3x3x3 ft pits and covered with ash under the shade (T2, potatoes stored in3x3x3 ft pits and covered with rice husk under the shade (T3, potatoes stored in3x3x3 ft pits and covered with a wood shavings under the shade (T4, potatoes spread on a bamboo platform under the shade(T5, potatoes spread on a raffia palm platform under the shade(T6, potatoes spread on concrete pavement inside the barn (T7, potatoes spread on the ground under the shade(T8, potatoes buried under the ground (T9. T8 was used as the control treatment. Temperature and relative humidity of the environment was monitored, the roots were weighed monthly to access the weight loss, sprouting and rot were observed visually and proximate composition of the stored roots were evaluated using standard methods. The lowest percentage weight loss was observed in samples stored in a pit covered with wood ash and those covered with river sand. Samples stored in pits and covered with wood shavings, wood ash and river sand had the lowest percentage of sprouting (1.63%, 3.45% and 6.06% respectively. The dry matter content increased with storage period in all the storage methods. The starch yield varied in the different storage methods with the samplescovered with river sand (13.45% and the samples buried underground in the field(10.53% giving the highest starch yield at the end of the storage period. Samples stored under rice husk had the highest ash content (4.77% while the crude fibre and crude protein contents were highest in the samples spread on raffia palm. The results showed that spreading on the floor

Grain preservation in SSSR

International Nuclear Information System (INIS)

Trisviatski, L.A.

1973-01-01

First the importance of cereals collected in the S.S.S.R., the reason why the government had to put in practice a storage chain, composed of large capacity store houses (200 000 metric tonnes, or more) is reminded. When climatic conditions result in wet harvested grains, cereals are dried either in state enterprise dryers (32 to 50 tonnes/hour) or in kolkhozes' dryers (2 to 16 tonnes/hour). A new type of drying with recycling, has been developped, economizing 10 to 15 p. 100. Then the possibilities offered by the technique of partial drying of very wet grains are studied and the preservation processes using fresh ventilation, or hot ventilation with drying effect are described. The question of silage of wet grains destined to animal consumption is then examined as well as preservation by sodium pyrosulfide; the use of propionic acid, little developped in SSSR, is studied now, just as storage with inert gas. The struggle technics against insects, either with chemical agents, or with irradiation are described. Finally the modalities of technicians formation, specialized in preservation, are discussed [fr

Parturition pit: the bony imprint of vaginal birth

International Nuclear Information System (INIS)

McArthur, Tatum A.; Meyer, Isuzu; Jackson, Bradford; Pitt, Michael J.; Larrison, Matthew C.

2016-01-01

To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p < 0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p < 0.0001). No males had pits. Our study indicates that parturition pits are associated with prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists. (orig.)

Post-pit optimization strategic alignment

OpenAIRE

Breed, M.F.; van Heerden, D.

2016-01-01

Successful development of projects or life-of-mine strategies requires an understanding of the relative sensitivity of value drivers such as grade, tonnage, energy costs, direct operational costs, and recoveries. For example, the results could vary significantly depending on the grade strategy, given a specific orebody amenable to open pitting. Pit optimization is a very powerful tool widely used in the industry to determine the pit shell with the most attractive value potential. Based on the...

Differences in grain ultrastructure, phytochemical and proteomic profiles between the two contrasting grain Cd-accumulation barley genotypes.

Directory of Open Access Journals (Sweden)

Hongyan Sun

Full Text Available To reveal grain physio-chemical and proteomic differences between two barley genotypes, Zhenong8 and W6nk2 of high- and low-grain-Cd-accumulation, grain profiles of ultrastructure, amino acid and proteins were compared. Results showed that W6nk2 possesses significantly lower protein content, with hordein depicting the greatest genotypic difference, compared with Zhenong8, and lower amino acid contents with especially lower proportion of Glu, Tyr, Phe and Pro. Both scanning and transmission electron microscopy observation declared that the size of A-type starch molecule in W6nk2 was considerably larger than that of Zhenong8. Grains of Zhenong8 exhibited more protein-rich deposits around starch granules, with some A-type granules having surface pits. Seventeen proteins were identified in grains, using 2-DE coupled with mass spectrometry, with higher expression in Zhenong8 than that in W6nk2; including z-type serpin, serpin-Z7 and alpha-amylase/trypsin inhibitor CM, carbohydrate metabolism, protein synthesis and signal transduction related proteins. Twelve proteins were less expressed in Zhenong8 than that in W6nk2; including barley trypsin inhibitor chloroform/methanol-soluble protein (BTI-CMe2.1, BTI-CMe2.2, trypsin inhibitor, dehydroascorbate reductase (DHAR, pericentrin, dynein heavy chain and some antiviral related proteins. The data extend our understanding of mechanisms underlying Cd accumulation/tolerance and provides possible utilization of elite genetic resources in developing low-grain-Cd barley cultivars.

Interim storage of dismantled nuclear weapon components at the U.S. Department of Energy Pantex Plant

International Nuclear Information System (INIS)

Guidice, S.J.; Inlow, R.O.

1995-01-01

Following the events of 1989 and the subsequent cessation of production of new nuclear weapons by the US, the mission of the Department of Energy (DOE) Nuclear Weapons Complex has shifted from production to dismantlement of retired weapons. The sole site in the US for accomplishing the dismantlement mission is the DOE Pantex Plant near Amarillo, Texas. Pending a national decision on the ultimate storage and disposition of nuclear components form the dismantled weapons, the storage magazines within the Pantex Plant are serving as the interim storage site for pits--the weapon plutonium-bearing component. The DOE has stipulated that Pantex will provide storage for up to 12,000 pits pending a Record of Decision on a comprehensive site-wide Environmental Impact Statement in November 1996

Influence of Pitting Corrosion on Fatigue and Corrosion Fatigue of Ship and Offshore Structures, Part II: Load - Pit - Crack Interaction

Directory of Open Access Journals (Sweden)

Jakubowski Marek

2015-09-01

Full Text Available In the paper has been discussed influence of stresses on general corrosion rate and corrosion pit nucleation rate and growth , whose presence has been questioned by some authors but accepted by most of them. Influence of roughness of pit walls on fatigue life of a plate suffering pit corrosion and presence of the so called „ non-damaging” pits which never lead to initiation of fatigue crack, has been presented. Possibility of prediction of pit-to-crack transition moment by two different ways, i.e. considering a pit a stress concentrator or an equivalent crack, has been analyzed. Also, influence of statistical distribution of depth of corrosion pits as well as anticorrosion protection on fatigue and corrosion fatigue has been described.

pitting corrosion susceptibility pitting corrosion susceptibility of aisi

African Journals Online (AJOL)

eobe

2DEPARTMENT OF MECHANICAL ENGINEERING, UNIVERSITY OF BENIN, BENIN- CITY, EDO STATE, NIGERIA. E-mail addresses: ... fluids and aggressive chemicals. Pitting corrosion ... the kitchen, food manufacturing and dispensing and.

Industrial application of radiation disinfestation of grain

International Nuclear Information System (INIS)

Zakladnoj, G.A.; Men'shenin, A.I.; Pertsovskij, E.S.; Salimov, R.A.; Cherepkov, V.G.; Krsheminskij, V.S.

1982-01-01

One of the main reasons for grain losses during storage is its damage by pest insects. Chemical methods widely used at present for grain decontamination have some shortcomings. In this connection a radiation method for grain disinfestation is developed and introduced in industry. First in the world experimental-industrial disinfestator on the base of electron accelerators is put into operation at Odessa port elevator

Retention of radiolytic CO gas in irradiated pepper grains and irradiation detection of spices and dry grains with the level of stocked CO gas

International Nuclear Information System (INIS)

Furuta, M.; Dohmaru, T.; Katayama, T.; Toratani, H.; Takeda, A.

1995-01-01

The release of radiolytic CO gas from 60Co gamma-irradiated pepper seeds was unexpectedly slower than that of radiolytic H2 gas during a storage period after irradiation. These gases were retained in the grains and could be recovered by pulverization under gaslight condition. Using this procedure, 10-kGy-irradiated pepper grains could be distinguished from nonirradiated samples for more than 2 months by the level of CO and H2 gases. The patterns of CO change at 10, 20, and 30 kGy were similar, and the CO amounts were proportional to irradiation doses at any point of the storage period after irradiation. 60Co gamma-irradiated grains of allspice, cinnamon, cumin, polished rice, and wheat could be distinguished from nonirradiated ones by the level of retained CO gas even after 2 months of storage at room temperature. Thus, radiolytic CO gas could be an effective probe for rapid screening of irradiated pepper and dry grains

Oxygen pitting failure of a bagasse boiler tube

CSIR Research Space (South Africa)

Heyes, AM

2001-04-01

Full Text Available Examination of a failed roof tube from a bagasse boiler showed transverse through-cracks and extensive pitting. The pitting was typically oxygen induced pitting and numerous fatigue cracks had started within these pits. It is highly probable...

Accountability Quality Shuffler Measurements on Pits

International Nuclear Information System (INIS)

Rinard, P.M.

2000-01-01

Pits have generally been treated as accountable units that are intact if merely present and they are excluded from the more demanding nondestructive assay requirements. As pits begin to flow into disposition streams, there may be more incentive to measure the masses of their fissile components for accountability purposes. This Department of Energy Office of Safeguards and Security (OSS) Lifecycle Project has explored some ways in which such measurements may be done successfully. The active neutron instrument called a shuffler has been used to measure a variety of actual pits, and a calculational technique has been developed to accurately predict such count rates. Passive multiplicity counting has previously been applied to pits for determining their plutonium contents. This combination of measurement and calculational techniques provide powerful and accurate tools for determining the fissile contents of pits with the quality needed for accountability purposes

Storage and retrieval of electromagnetic waves with orbital angular momentum via plasmon-induced transparency.

Science.gov (United States)

Bai, Zhengyang; Xu, Datang; Huang, Guoxiang

2017-01-23

We propose a scheme to realize the storage and retrieval of high-dimensional electromagnetic waves with orbital angular momentum (OAM) via plasmon-induced transparency (PIT) in a metamaterial, which consists of an array of meta-atoms constructed by a metallic structure loaded with two varactors. We show that due to PIT effect the system allows the existence of shape-preserving dark-mode plasmonic polaritons, which are mixture of electromagnetic-wave modes and dark oscillatory modes of the meta-atoms and may carry various OAMs. We demonstrate that the slowdown, storage and retrieval of multi-mode electromagnetic waves with OAMs can be achieved through the active manipulation of a control field. Our work raises the possibility for realizing PIT-based spatial multi-mode memory of electromagnetic waves and is promising for practical application of information processing with large capacity by using room-temperature metamaterials.

DEVELOPMENT OF GRAIN MARKET IN UKRAINE

Directory of Open Access Journals (Sweden)

Aleksandr Maslak

2015-11-01

Full Text Available The subject of the research is a set of theoretical, methodological and practical fundamentals of organizational and economic functioning are integrated agricultural formations in the grain market of Ukraine. The methodological basis of research is the complex analysis of economic processes in the grain market in Ukraine and the world. During research we used such methods as method of systematization and comparison, statistic, economic, balance, constructive, target-oriented, and the methods of induction and deduction, analogy and comparison. Main aim of this article is the analysis of the situation on the grain market in Ukraine, defining the role of integrated agricultural formations in this market, improving the organizational-economic mechanism of its functioning, identifies ways of improving the competitiveness of Ukraine among world exporters of grain. Using results of the studies we examined trends grain market in Ukraine; influence of businesses in grain production; analysis of constraints to improve production efficiency of grain; defined domestic (internal needs of grain in Ukraine; assessed the status and expediency transformation infrastructure of the grain market of Ukraine; defined priority directions of development of the grain market in Ukraine. As a result of the preparation of articles, it is obtained the following conclusions: Ukraine is the world's largest producers and exporters of grain, the production of integrated agricultural units to a third of the total grain; technical condition of farm does not meet the needs of production; the domestic market is unable to provide the existing demand for grain production, contributing to export growth; Ukraine has a number of problems due to increased grain production, namely the shortage of storage capacity for the storage of grain, limited performance transshipment of grain in port elevators and imperfection and depreciation of transport systems; solving the existing problems is

Evaluation of thermal hydraulics characteristics of natural cooling low level radioactive waste storage system

International Nuclear Information System (INIS)

Yoshii, Toshihiro; Iwaki, Chikako; Ikeda, Tatsumi; Ikeda, Hiroshi; Koyama, Tomonori; Usui, Nobuhiko; Watanabe, Hisao; Masaki, Yoshikazu

2012-01-01

It is necessary to design a low level radioactive waste storage system so that the decay heat of radioactive waste does not breach the structural safety limit. Currently, this waste storage system is designed as a natural cooling system, which continuously cools the radioactive waste without an active device. It consists simply of a storage pit for radioactive waste and air inlet and outlet ducts. The radioactive waste is cooled by natural convective air flow, which is generated by the buoyancy of heated air due to the decay heat of radioactive waste. It is important to clarify the flow characteristics in the systems in order to evaluate the cooling performance. The air mass flow rate through the system is determined by the balance between the natural convective flow force and pressure loss within the system. Therefore, the pressure drop and flow pattern in the waste storage pit are important flow characteristics. In this study, the pressure drop and air temperature distribution, greatly influenced by the flow pattern in the pit, were measured using a 1/5 scale model and compared with the results obtained from CFD. Flow network analysis, which is a simple model that simulates the flow by nodes and junctions, was conducted and its validity was confirmed by experimental results and CFD. (author)

Grain Entrapment Pressure on the Torso: Can You Breathe while Buried in Grain?

Science.gov (United States)

Moore, Kevin G; Jones, Carol L

2017-04-26

The pressure applied to the chest and back of a simulated grain entrapment victim was measured. Pressure sensors were attached to the chest and back of a manikin that was buried in grain in the vertical position. Measurements were made in four grain types at four grain depths ranging from the top of the manikin's shoulders to 0.61 m (24 in.) over the head. The pressure ranged from 1.6 to 4.0 kPa (0.23 to 0.57 psi). Based on available physiological information, this amount of pressure is unlikely to limit the respiration of an otherwise healthy adult male victim. However, other factors, such as the victim's age, gender, and body position in the grain, may influence respiration. The aspiration of grain appears to be the most likely asphyxiation risk during grain bin entrapment. Entering a grain storage bin is inherently dangerous, and Occupational Safety and Health Administration (OSHA) guidelines for permit-required confined spaces and grain handling facilities must be followed. Due to the risk of grain aspiration during engulfment, the development of safety equipment that could help protect the airway of a victim should be investigated. Copyright© by the American Society of Agricultural Engineers.

Outline of a method for final storage of low- and medium-active waste from possible Danish power reactors

International Nuclear Information System (INIS)

Brodersen, K.; Jensen, J.; Oestergaard, K.

1977-02-01

A method is outlined for the final storage of Danish low-and medium-active power reactor waste. The waste drums are contained in large concretre blocks placed just below the ground surface. A plant for storing waste by means of this method is sketched. It consists of a system of reinforced concrete pits with the top level with the ground surface. Each pit measures c. 5 x 5 m and is c. 6 m deep. The pits are envisaged cast with a permanent inside, step-like shuttering of thin steel plates. The volume between the drums will be cast with concrete when a pit is filled. Calculations are given of the construction and running costs. It is estimated that the final storage of reactor wastes is only a small problem regarding economy and space, and also that there is hardly doubt that full safety can be achieved. (B.P.)

Surface modifications on toughened, fine-grained, recrystallized tungsten with repetitive ELM-like pulsed plasma irradiation

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Y., E-mail: ykikuchi@eng.u-hyogo.ac.jp [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Sakuma, I.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M. [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, 671-2280 Hyogo (Japan); Ueda, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kurishita, H. [Institute for Materials Research, Tohoku University, Ibaraki 311-1313 (Japan)

2015-08-15

Surface modifications of toughened, fine-grained, recrystallized tungsten (TFGR W) materials with 1.1 wt.% TiC and 3.3 wt.% TaC dispersoids due to repetitive ELM-like pulsed (∼0.15 ms) helium plasma irradiation have been investigated by using a magnetized coaxial plasma gun. No surface cracking at the center part of the TFGR W samples exposed to 20 plasma pulses of ∼0.3 MJ m{sup −2} was observed. The suppression of surface crack formation due to the increase of the grain boundary strength by addition of TiC and TaC dispersoids was confirmed in comparison with a pure W material. On the other hand, surface cracks and small pits appeared at the edge part of the TFGR W sample after the pulsed plasma irradiation. Erosion of the TiC and TaC dispersoids due to the pulsed plasma irradiation could cause the small pits on the surface, resulting in the surface crack formation.

Surface modifications on toughened, fine-grained, recrystallized tungsten with repetitive ELM-like pulsed plasma irradiation

Science.gov (United States)

Kikuchi, Y.; Sakuma, I.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.; Ueda, Y.; Kurishita, H.

2015-08-01

Surface modifications of toughened, fine-grained, recrystallized tungsten (TFGR W) materials with 1.1 wt.% TiC and 3.3 wt.% TaC dispersoids due to repetitive ELM-like pulsed (∼0.15 ms) helium plasma irradiation have been investigated by using a magnetized coaxial plasma gun. No surface cracking at the center part of the TFGR W samples exposed to 20 plasma pulses of ∼0.3 MJ m-2 was observed. The suppression of surface crack formation due to the increase of the grain boundary strength by addition of TiC and TaC dispersoids was confirmed in comparison with a pure W material. On the other hand, surface cracks and small pits appeared at the edge part of the TFGR W sample after the pulsed plasma irradiation. Erosion of the TiC and TaC dispersoids due to the pulsed plasma irradiation could cause the small pits on the surface, resulting in the surface crack formation.

Effect of Welding Process on Microstructure, Mechanical and Pitting Corrosion Behaviour of 2205 Duplex Stainless Steel Welds

Science.gov (United States)

Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

2018-03-01

An attempt has been made to weld 2205 Duplex stainless steel of 6mm thick plate using conventional gas tungsten arc welding (GTAW) and activated gas tungsten arc welding (A- GTAW) process using silica powder as activated flux. Present work is aimed at studying the effect of welding process on depth of penetration, width of weld zone of 2205 duplex stainless steel. It also aims to observe the microstructural changes and its effect on mechanical properties and pitting corrosion resistance of 2205 duplex stainless steel welds. Metallography is done to observe the microstructural changes of the welds using image analyzer attached to the optical microscopy. Hardness studies, tensile and ductility bend tests were evaluated for mechanical properties. Potentio-dynamic polarization studies were carried out using a basic GillAC electro-chemical system in 3.5% NaCl solution to observe the pitting corrosion behaviour. Results of the present investigation established that increased depth of penetration and reduction of weld width in a single pass by activated GTAW with the application of SiO2 flux was observed when compared with conventional GTAW process. It may be attributed to the arc constriction effect. Microstructure of the weld zones for both the welds is observed to be having combination of austenite and delta ferrite. Grain boundary austenite (GBA) with Widmanstatten-type austenite (WA) of plate-like feature was nucleated from the grain boundaries in the weld zone of A-GTAW process. Mechanical properties are relatively low in activated GTAW process and are attributed to changes in microstructural morphology of austenite. Improved pitting corrosion resistance was observed for the welds made with A-GTAW process.

Demonstration of In-Situ Stabilization of Buried Waste at Pit G-11 at the Brookhaven National laboratory Glass Pits Disposal Site

International Nuclear Information System (INIS)

Dwyer, B.P.; Gilbert, J.; Heiser, J.

1999-01-01

In 1989 BNL was added to the EPAs National Priorities List. The site is divided into seven operable units (OU). OU-I includes the former landfill area. The field task site is noted as the AOC 2C Glass Holes location. Beginning in the 1960s and continuing into the 1980s, BNL disposed of laboratory waste (glassware, chemicals and animal carcasses) in numerous shallow pits. The drivers for remediating the pits are; historical records that indicate hazardous materials may have been disposed of in the pits; ground water contamination down gradient of the pits; a test excavation of one of the glass holes that unearthed laboratory glass bottles with unidentified liquids still contained; and the fact that BNL rests atop an EPA designated sole-source aquifer. The specific site chosen for this demonstration was pit G-11. The requirements that lead to choosing this pit were; a well characterized pit and a relatively isolated pit where our construction operations would not impact on adjacent pits. The glass holes area, including pit G-11, was comprehensively surveyed using a suite of geophysical techniques (e.g., EM-31, EM-61, GPR). Prior to stabilizing the waste form a subsurface barrier was constructed to contain the entire waste pit. The pit contents were then stabilized using a cement grout applied via jet grouting. The stabilization was performed to make removal of the waste from the pit easier and safer in terms of worker exposure. The grouting process would mix and masticate the waste and grout and form a single monolithic waste form. This large monolith would then be subdivided into smaller 4 foot by 4 foot by 10-12 foot block using a demolition grout. The smaller blocks would then be easily removed from the site and disposed of in a CERCLA waste site

Experimental Stress Analysis at Railway Inspection Pit

Directory of Open Access Journals (Sweden)

Nicuşor Laurentiu Zaharia

2008-10-01

Full Text Available Railway inspection pits are used in railway halls. The purpose of inspection pits is to allow the working under the vehicle. Inspection pits can be found in locomotive depots, factories etc. The new design for a inspection pit in a railway hall involve tests in purpose of homologations the railway infrastructure. Before the homologation committee meeting, tests are made; after the test, a testing report is made which it will be part at homologation documents.

Pits on Ascraeus

Science.gov (United States)

2005-01-01

24 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows collapse pits and troughs on the lower northeast flank of the giant martian volcano, Ascraeus Mons. Layers of volcanic rock are evident in some of the pit and valley walls, and boulders the size of houses and trucks that were liberated from these walls by gravity can be seen on the floors of the depressions. Location near: 13.6oN, 102.6oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

Surface Textural Analysis of Quartz Grains from Modern Point Bar Deposits in Lower Reaches of the Yellow River

Science.gov (United States)

Cheng, Yong; Liu, Cong; Lu, Ping; Zhang, Yu; Nie, Qi; Wen, Yiming

2018-01-01

The surfaces of quartz grains contain characteristic textures formed during the process of transport, due to their stable physical and chemical properties. The surface textures include the information about source area, transporting force, sedimentary environment and evolution history of sediment. Surface textures of quartz grains from modern point bar deposits in the lower reaches of the Yellow River are observed and studied by scanning electron microscopy (SEM). Results indicate that there are 22 kinds of surface textures. The overall surface morphology of quartz grains shows short transporting time and distance and weak abrasive action of the river water. The combined surface textures caused by mechanical action indicate that quartz grains are transporting in a high-energy hydrodynamic condition and suffer a strong mechanical impact and abrasion. The common solution pits prove that the chemical property of transportation medium is very active and quartz grains receive an obvious chemical action. The combination of these surface textures can be an identification mark of fluvial environment, and that is: quartz grains are main subangular outline, whose roundness is higher with the farther motion distance; Surface fluctuation degree of quartz grains is relatively high, and gives priority to high and medium relief; V-shaped percussion marks are very abundant caused by mechanical action; The conchoidal of different sizes and steps are common-developed with paragenesis relationship; Solution pits are common-developed as well. The study makes up for the blank of surface textures analysis of quartz grains from modern fluvial deposits in China. It provides new ideas and evidence for studies of the sedimentary process and environmental significance, although the deep meanings of these micro textures remain to be further researched.

Increasing abscisic acid levels by immunomodulation in barley grains induces precocious maturation without changing grain composition.

Science.gov (United States)

Staroske, Nicole; Conrad, Udo; Kumlehn, Jochen; Hensel, Götz; Radchuk, Ruslana; Erban, Alexander; Kopka, Joachim; Weschke, Winfriede; Weber, Hans

2016-04-01

Abscisic acid (ABA) accumulates in seeds during the transition to the seed filling phase. ABA triggers seed maturation, storage activity, and stress signalling and tolerance. Immunomodulation was used to alter the ABA status in barley grains, with the resulting transgenic caryopses responding to the anti-ABA antibody gene expression with increased accumulation of ABA. Calculation of free versus antibody-bound ABA reveals large excess of free ABA, increasing signficantly in caryopses from 10 days after fertilization. Metabolite and transcript profiling in anti-ABA grains expose triggered and enhanced ABA-functions such as transcriptional up-regulation of sucrose-to-starch metabolism, storage protein synthesis and ABA-related signal transduction. Thus, enhanced ABA during transition phases induces precocious maturation but negatively interferes with growth and development. Anti-ABA grains display broad constitutive gene induction related to biotic and abiotic stresses. Most of these genes are ABA- and/or stress-inducible, including alcohol and aldehyde dehydrogenases, peroxidases, chaperones, glutathione-S-transferase, drought- and salt-inducible proteins. Conclusively, ABA immunomodulation results in precocious ABA accumulation that generates an integrated response of stress and maturation. Repression of ABA signalling, occurring in anti-ABA grains, potentially antagonizes effects caused by overshooting production. Finally, mature grain weight and composition are unchanged in anti-ABA plants, although germination is somewhat delayed. This indicates that anti-ABA caryopses induce specific mechanisms to desensitize ABA signalling efficiently, which finally yields mature grains with nearly unchanged dry weight and composition. Such compensation implicates the enormous physiological and metabolic flexibilities of barley grains to adjust effects of unnaturally high ABA amounts in order to ensure and maintain proper grain development. © The Author 2016. Published by

Computer simulation of pitting potential measurements

International Nuclear Information System (INIS)

Laycock, N.J.; Noh, J.S.; White, S.P.; Krouse, D.P.

2005-01-01

A deterministic model for the growth of single pits in stainless steel has been combined with a purely stochastic model of pit nucleation. Monte-Carlo simulations have been used to compare the predictions of this model with potentiodynamic experimental measurements of the pitting potential. The quantitative agreement between model and experiment is reasonable for both 304 and 316 stainless steel, and the effects of varying surface roughness, solution chloride concentration and potential sweep rate have been considered

PIT 9 Project: A private sector initiative

International Nuclear Information System (INIS)

Macdonald, D.W.; Hughes, F.P.; Burton, B.N.

1993-01-01

The Pit 9 Comprehensive Demonstration is intended to demonstrate a cost-effective approach to remediate an Idaho National Engineering Lab. (INEL) waste disposal pit through a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Interim Action. The remediation will include additional requirements, if needed, to provide high confidence that only minor additional work would be necessary to accomplish the final closure as part of the overall final closure strategy for the INEL's Subsurface Disposal Area (SDA). Pit 9 is an inactive waste disposal pit located in the northeastern corner of the SDA at the INEL's Radioactive Waste Management Complex (RWMC). It covers approximately 1 acre. The waste within Pit 9 is primarily transuranic waste generated at the Rocky Flats Plant and additional wastes, both hazardous and low-level radioactive, from generators at the INEL

Tracing the contribution of debris flow-dominated channels to gravel-bed torrential river channel: implementing pit-tags in the upper Guil River (French Alps)

Science.gov (United States)

Arnaud-Fassetta, Gilles; Lissak, Candide; Fort, Monique; Bétard, François; Carlier, Benoit; Cossart, Etienne; Madelin, Malika; Viel, Vincent; Charnay, Bérengère; Bletterie, Xavier

2014-05-01

In the upper, wider reaches of Alpine valleys, shaping of active channels is usually subject to rapid change. It mostly depends upon hydro-climatic variability, runoff concentration and sediment supply, and may result in alternating sequences of fluvial and debris-flow pulses, as recorded in alluvial fans and terraces. Our study, carried in the frame of SAMCO (ANR) project, focuses on the upper Guil River Valley (Queyras, Southern French Alps) cut into the slaty shale "schistes lustrés". Steep, lower order drains carry a contrasted solid discharge, including predominantly sandy-loam particles mixed with gravels and boulders (sandstone schists, ophiolites). Abundant sediment supply by frost shattering, snow avalanche and landslides is then reworked during snowmelt or summer storm runoff events, and may result in catastrophic, very destructive floods along the main channel, as shown by historical records. Following the RI-30 year 2000 flood, our investigations included sediment budgets, i.e. balance of erosion and deposition, and the mapping of the source, transport and storage of various sediments (talus, colluvium, torrential fans, terraces). To better assess sediment fluxes and sediment delivery into the main channel network, we implemented tracers (pit-tags) in selected sub-catchments, significantly contributing to the sediment yield of the valley bottoms during the floods and/or avalanches: Maloqueste, Combe Morel, Bouchouse and Peyronnelle catchments. The first three are direct tributaries of the Guil River whereas the Peyronnelle is a left bank tributary of the Peynin River, which joins the Guil River via an alluvial cone with high human and material stakes. The Maloqueste and the Combe Morel are two tributaries facing each other in the Guil valley, representing a double lateral constraint for the road during flood events of the Guil River. After pit-tag initialisation in laboratory, we set them up along the four tributaries: Maloqueste (20 pit-tags), Combe

Analysis of BY-106 pump pit cover plate

International Nuclear Information System (INIS)

Coverdell, B.L.

1994-01-01

A new cover for the pump pit of Tank 241-BY-106 has been designed to allow the rotary core exhauster to be hooked up without requiring pit entry, riser modification, or equipment removal. The new pit cover is necessary to allow installation of two risers for reducing exposure, contamination, and waste. Computer analysis indicates that the safety margin of the pit cover plate with two risers is adequate. The computer stress model and input files are attached. The pit cover plate is a replacement for an existing plate; therefore seismic and wind loads were considered for the plate only

Long-term plutonium storage: Design concepts

International Nuclear Information System (INIS)

Wilkey, D.D.; Wood, W.T.; Guenther, C.D.

1994-01-01

An important part of the Department of Energy (DOE) Weapons Complex Reconfiguration (WCR) Program is the development of facilities for long-term storage of plutonium. The WCR design goals are to provide storage for metals, oxides, pits, and fuel-grade plutonium, including material being held as part of the Strategic Reserve and excess material. Major activities associated with plutonium storage are sorting the plutonium inventory, material handling and storage support, shipping and receiving, and surveillance of material in storage for both safety evaluations and safeguards and security. A variety of methods for plutonium storage have been used, both within the DOE weapons complex and by external organizations. This paper discusses the advantages and disadvantages of proposed storage concepts based upon functional criteria. The concepts discussed include floor wells, vertical and horizontal sleeves, warehouse storage on vertical racks, and modular storage units. Issues/factors considered in determining a preferred design include operational efficiency, maintenance and repair, environmental impact, radiation and criticality safety, safeguards and security, heat removal, waste minimization, international inspection requirements, and construction and operational costs

Structures of Bordered Pits Potentially Contributing to Isolation of a Refilled Vessel from Negative Xylem Pressure in Stems of Morus australis Poir.: Testing of the Pit Membrane Osmosis and Pit Valve Hypotheses.

Science.gov (United States)

Ooeda, Hiroki; Terashima, Ichiro; Taneda, Haruhiko

2017-02-01

Two hypotheses have been proposed to explain the mechanism preventing the refilling vessel water from being drained to the neighboring functional vessels under negative pressure. The pit membrane osmosis hypothesis proposes that the xylem parenchyma cells release polysaccharides that are impermeable to the intervessel pit membranes into the refilling vessel; this osmotically counteracts the negative pressure, thereby allowing the vessel to refill. The pit valve hypothesis proposes that gas trapped within intervessel bordered pits isolates the refilling vessel water from the surrounding functional vessels. Here, using the single-vessel method, we assessed these hypotheses in shoots of mulberry (Morus australis Poir.). First, we confirmed the occurrence of xylem refilling under negative pressure in the potted mulberry saplings. To examine the pit membrane osmosis hypothesis, we estimated the semi-permeability of pit membranes for molecules of various sizes and found that the pit membranes were not semi-permeable to polyethylene glycol of molecular mass osmosis mechanism in mulberry would be unrealistically large. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Long-term storage of sweetpotato by small-scale farmers through ...

African Journals Online (AJOL)

Mo

by high-performance liquid chromatography, HPLC (Class-. VP, LC-10ATVP, Kyoto, ... and fructose) were measured according as described by. Picha (1985) using ..... pit storage method (Figure 7b), and similarly for Naspot 1 and Ejumula ...

Insect Population Dynamics in Commercial Grain Elevators

Science.gov (United States)

Data were collected in 1998-2002 from wheat stored in commercial grain elevators in south-central Kansas. Storage bins at these elevators had concrete walls and were typically 6-9 m in diameter and 30-35 m tall. A vacuum-probe sampler was used to collect ten 3-kg grain samples in the top 12 m of the...

Storage of Maize in Purdue Improved Crop Storage (PICS) Bags.

Science.gov (United States)

Williams, Scott B; Murdock, Larry L; Baributsa, Dieudonne

2017-01-01

Interest in using hermetic technologies as a pest management solution for stored grain has risen in recent years. One hermetic approach, Purdue Improved Crop Storage (PICS) bags, has proven successful in controlling the postharvest pests of cowpea. This success encouraged farmers to use of PICS bags for storing other crops including maize. To assess whether maize can be safely stored in PICS bags without loss of quality, we carried out laboratory studies of maize grain infested with Sitophilus zeamais (Motshulsky) and stored in PICS triple bags or in woven polypropylene bags. Over an eight month observation period, temperatures in the bags correlated with ambient temperature for all treatments. Relative humidity inside PICS bags remained constant over this period despite the large changes that occurred in the surrounding environment. Relative humidity in the woven bags followed ambient humidity closely. PICS bags containing S. zeamais-infested grain saw a significant decline in oxygen compared to the other treatments. Grain moisture content declined in woven bags, but remained high in PICS bags. Seed germination was not significantly affected over the first six months in all treatments, but declined after eight months of storage when infested grain was held in woven bags. Relative damage was low across treatments and not significantly different between treatments. Overall, maize showed no signs of deterioration in PICS bags versus the woven bags and PICS bags were superior to woven bags in terms of specific metrics of grain quality.

Grain surface features and clay mineralogy of the quaternary sediments from Western Deccan Trap Region, India, and their palaeoclimatic significance

Directory of Open Access Journals (Sweden)

Veena U. Joshi

2011-06-01

Full Text Available Quartz sand grains obtained from a deeply gullied topography along the banks of two tributaries of River Pravara in Maharashtra (India have been examined with a scanning electron microscope (SEM. Quartz grains have been selected after a heavy mineral separation and micro-photographs of each grain were taken at various angles and magnifications. The sediments reveal features resulting from mechanical grinding as well as from chemical alteration. Conchoidal fractures, cleavage planes, grooves, v-shaped indentations etc. are the mechanical features documented on the grains whereas solution pits of varying sizes and intensity, precipitation surfaces, oriented v-pits, solution crevasses and etching are the features of chemical origin. Several evidences indicate that the samples have undergone digenetic changes. Few grains show the features of intense chemical breakdown. The overall assemblages of the grain surface features suggest that the samples have been subjected to subaqueous transport for a considerable period of time. The minor chemical features such as solution pits or semi circular arcuate steps found in abundance on these grains are due to the dissolution of the sediments in a low energy fluviatile environment. For clay mineralogy, fractions between <2 and <0.2 mm were separated out from the sediments. The clay fractions were then subjected to examination by X-ray diffraction (XRD of oriented K/Ca saturated samples using a Philips Diffractometer and Ni-filtered Cu Ka radiation with the scanning speed of 10 2Ө min -1. The main clay minerals for all the samples are identical and show the presence of hydroxy-interlayered smectites with minor quantities of mica, kaolinite, smectites, quartz and feldspar. The first weathering product of the Deccan Basalt (DB is the dioctahedral smectite. Since the present semi aridic climatic condition of the study area can not transform a smectite to HIS and either smectite to kaolin, it is quite likely that

Markov Chain Models for the Stochastic Modeling of Pitting Corrosion

Directory of Open Access Journals (Sweden)

A. Valor

2013-01-01

Full Text Available The stochastic nature of pitting corrosion of metallic structures has been widely recognized. It is assumed that this kind of deterioration retains no memory of the past, so only the current state of the damage influences its future development. This characteristic allows pitting corrosion to be categorized as a Markov process. In this paper, two different models of pitting corrosion, developed using Markov chains, are presented. Firstly, a continuous-time, nonhomogeneous linear growth (pure birth Markov process is used to model external pitting corrosion in underground pipelines. A closed-form solution of the system of Kolmogorov's forward equations is used to describe the transition probability function in a discrete pit depth space. The transition probability function is identified by correlating the stochastic pit depth mean with the empirical deterministic mean. In the second model, the distribution of maximum pit depths in a pitting experiment is successfully modeled after the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time is simulated as the realization of a Weibull process. Pit growth is simulated using a nonhomogeneous Markov process. An analytical solution of Kolmogorov's system of equations is also found for the transition probabilities from the first Markov state. Extreme value statistics is employed to find the distribution of maximum pit depths.

W-12 valve pit decontamination demonstration

International Nuclear Information System (INIS)

Benson, C.E.; Parfitt, J.E.; Patton, B.D.

1995-12-01

Waste tank W-12 is a tank in the ORNL Low-Level Liquid Waste (LLLW) system that collected waste from Building 3525. Because of a leaking flange in the discharge line from W-12 to the evaporator service tank (W-22) and continual inleakage into the tank from an unknown source, W-12 was removed from service to comply with the Federal Facilities Agreement requirement. The initial response was to decontaminate the valve pit between tank W-12 and the evaporator service tank (W-22) to determine if personnel could enter the pit to attempt repair of the leaking flange. Preventing the spread of radioactive contamination from the pit to the environment and to other waste systems was of concern during the decontamination. The drain in the pit goes to the process waste system; therefore, if high-level liquid waste were generated during decontamination activities, it would have to be removed from the pit by means other than the available liquid waste connection. Remote decontamination of W-12 was conducted using the General Mills manipulator bridge and telescoping trolley and REMOTEC RM-10 manipulator. The initial objective of repairing the leaking flange was not conducted because of the repair uncertainty and the unknown tank inleakage. Rather, new piping was installed to empty the W-12 tank that would bypass the valve pit and eliminate the need to repair the flange. The radiological surveys indicated that a substantial decontamination factor was achieved

Pitting corrosion in austenitic stainless steel water tanks of hotel trains

International Nuclear Information System (INIS)

Moreno, D. A.; Garcia, A. M.; Ranninger, C.; Molina, B.

2011-01-01

The water storage tanks of hotel trains suffered pitting corrosion. To identify the cause, the tanks were subjected to a detailed metallographic study and the chemical composition of the austenitic stainless steels used in their construction was determined. Both the tank water and the corrosion products were further examined by physicochemical and microbiological testing. Corrosion was shown to be related to an incompatibility between the chloride content of the water and the base and filler metals of the tanks. These findings formed the basis of recommendations aimed at the prevention and control of corrosion in such tanks. (Author) 18 refs.

Pitting corrosion of copper. Further model studies

International Nuclear Information System (INIS)

Taxen, C.

2002-08-01

The work presented in this report is a continuation and expansion of a previous study. The aim of the work is to provide background information about pitting corrosion of copper for a safety analysis of copper canisters for final deposition of radioactive waste. A mathematical model for the propagation of corrosion pits is used to estimate the conditions required for stationary propagation of a localised anodic corrosion process. The model uses equilibrium data for copper and its corrosion products and parameters for the aqueous mass transport of dissolved species. In the present work we have, in the model, used a more extensive set of aqueous and solid compounds and equilibrium data from a different source. The potential dependence of pitting in waters with different compositions is studied in greater detail. More waters have been studied and single parameter variations in the composition of the water have been studied over wider ranges of concentration. The conclusions drawn in the previous study are not contradicted by the present results. However, the combined effect of potential and water composition on the possibility of pitting corrosion is more complex than was realised. In the previous study we found what seemed to be a continuous aggravation of a pitting situation by increasing potentials. The present results indicate that pitting corrosion can take place only over a certain potential range and that there is an upper potential limit for pitting as well as a lower. A sensitivity analysis indicates that the model gives meaningful predictions of the minimum pitting potential also when relatively large errors in the input parameters are allowed for

Production of aflatoxins during storage of gamma-irradiated wheat

International Nuclear Information System (INIS)

Behere, A.G.; Sharma, A.; Padwaldesai, S.R.; Nadkarni, G.B.

1978-01-01

A correlation between relative humidity (RH) during storage and moisture content was obtained in wheat subjected to gamma irradiation at 20 krad. The samples were assessed for storage up to 6 months with and without artificial loading of grains with conidia of Aspergillus flavus. The mycotoxin production seemed to be determined by a critical level of moisture in the grain (13%) at RH over 80% at 28 0 +- 2 0 C. The total aflatoxin produced in the irradiated grains was observed to be lower than in the unirradiated controls. The amount of toxin contained in grains, artificially infected with A. flavus before or after irradiation, did not show appreciable differences. The results, while defining the storage conditions with reference to humidity, did not indicate any alterations in wheat relating to aflatoxin producing potential

Pitting corrosion on a copper canister

International Nuclear Information System (INIS)

Hermansson, H.P.; Beverskog, B.

1996-02-01

It is demonstrated that normal pitting can occur during oxidizing conditions in the repository. It is also concluded that a new theory for pitting corrosion has to be developed, as the present theory is not in accordance with all practical and experimental observations. A special variant of pitting, based on the growth of sulfide whiskers, is suggested to occur during reducing conditions. However, such a mechanism needs to be demonstrated experimentally. A simple calculational model of canister corrosion was developed based on the results of this study. 69 refs, 3 figs

Technology and Policy for Suppressing Grain Dust Explosions in Storage Facilities

National Research Council Canada - National Science Library

1995-01-01

To ensure workplace safety, grain handling facilities engage in a variety of activities to control the accumulation of grain dust, such as good housekeeping practices, pneumatic systems, and liquid additives...

Insecticidal Activity of Essential Oil of Carum Carvi Fruits from China and Its Main Components against Two Grain Storage Insects

OpenAIRE

Fang, Rui; Jiang, Cai Hong; Wang, Xiu Yi; Zhang, Hai Ming; Liu, Zhi Long; Zhou, Ligang; Du, Shu Shan; Deng, Zhi Wei

2010-01-01

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Carum carvi fruits was found to possess strong contact toxicity against Sitophilus zeamais and Tribolium castaneum adults, with LD50 values of 3.07 and 3.29 mg/adult, respectively, and also showed strong fumigant toxicity against the two grain storage insects with LC50 values of 3.37 and 2.53 mg/L, respectively. The essential oil obtained by hydrodistillation was investigated by G...

The Application of Foundation Pit Monitoring Technology to the Excavation

Directory of Open Access Journals (Sweden)

Qiu Jin

2015-01-01

Full Text Available The foundation pit monitoring plays an important role in the foundation pit supporting projects especially in those deep foundation pit projects. Through the whole monitoring of the foundation pit construction from the excavation to the backfill, we can learn about the forcing and deforming process of the foundation pit supporting system, and grasp the impact of external condition changes on the foundation pit. This paper takes a project in Jinan as an example to establish a specific monitoring program, and then conducts the analysis and evaluation of the monitoring data; the real-time grasp of the foundation pit deformation and internal force changes can help to further ensure the security status of the foundation pit, thus better guiding the construction.

Modeling and management of pit lake water chemistry 1: Theory

International Nuclear Information System (INIS)

Castendyk, D.N.; Eary, L.E.; Balistrieri, L.S.

2015-01-01

Highlights: • Review of pit lake literature in the context of pit lake predictions. • Review of approaches used to predict pit wall-rock runoff and leachate. • Review of approaches used to generate a pit lake water balance. • Review of approaches used to generate a hydrodynamic prediction. • Review of approaches used to generate a geochemical prediction of a future pit lake. - Abstract: Pit lakes are permanent hydrologic/landscape features that can result from open pit mining for metals, coal, uranium, diamonds, oil sands, and aggregates. Risks associated with pit lakes include local and regional impacts to water quality and related impacts to aquatic and terrestrial ecosystems. Stakeholders rely on predictive models of water chemistry to prepare for and manage these risks. This paper is the first of a two part series on the modeling and management of pit lakes. Herein, we review approaches that have been used to quantify wall-rock runoff geochemistry, wall-rock leachate geochemistry, pit lake water balance, pit lake limnology (i.e. extent of vertical mixing), and pit lake water quality, and conclude with guidance on the application of models within the mine life cycle. The purpose of this paper is to better prepare stakeholders, including future modelers, mine managers, consultants, permitting agencies, land management agencies, regulators, research scientists, academics, and other interested parties, for the challenges of predicting and managing future pit lakes in un-mined areas

Inhibition of Copper Pitting Corrosion in Aggressive Potable Waters

Directory of Open Access Journals (Sweden)

Emily Sarver

2012-01-01

Full Text Available Copper pitting corrosion can lead to premature plumbing failures, and can be caused by aggressive potable waters characterized by high pH, free chlorine residual and low alkalinity. In such waters and under continuous flow, certain inhibitors including phosphate, silica or natural organic matter may greatly reduce pitting occurrence. In the current work, 1 mg/L phosphate (as P completely prevented initiation of pits, and 5 mg/L silica (as Si significantly decelerated pitting. However, much lower doses of these inhibitors had little benefit and actually accelerated the rate of attack in some cases. Effects of organic matter were dependent on both the type (e.g., natural versus ozonated humic substances and dosage. Dose-response effects of free chlorine and alkalinity were also investigated. Based on electrochemical data, pits initiated more rapidly with increased free chlorine, but even moderate levels of chlorine (~0.4 mg/L eventually caused severe pitting. High alkalinity decreased pit propagation rates but did not prevent pit formation.

Detecting pits in tart cherries by hyperspectral transmission imaging

Science.gov (United States)

Qin, Jianwei; Lu, Renfu

2004-11-01

The presence of pits in processed cherry products causes safety concerns for consumers and imposes potential liability for the food industry. The objective of this research was to investigate a hyperspectral transmission imaging technique for detecting the pit in tart cherries. A hyperspectral imaging system was used to acquire transmission images from individual cherry fruit for four orientations before and after pits were removed over the spectral region between 450 nm and 1,000 nm. Cherries of three size groups (small, intermediate, and large), each with two color classes (light red and dark red) were used for determining the effect of fruit orientation, size, and color on the pit detection accuracy. Additional cherries were studied for the effect of defect (i.e., bruises) on the pit detection. Computer algorithms were developed using the neural network (NN) method to classify the cherries with and without the pit. Two types of data inputs, i.e., single spectra and selected regions of interest (ROIs), were compared. The spectral region between 690 nm and 850 nm was most appropriate for cherry pit detection. The NN with inputs of ROIs achieved higher pit detection rates ranging from 90.6% to 100%, with the average correct rate of 98.4%. Fruit orientation and color had a small effect (less than 1%) on pit detection. Fruit size and defect affected pit detection and their effect could be minimized by training the NN with properly selected cherry samples.

Experience on wet storage spent fuel sipping at IEA-R1 Brazilian research reactor

International Nuclear Information System (INIS)

Perrotta, J.A.; Terremoto, L.A.A.; Zeituni, C.A.

1998-01-01

The IEA-R1 research reactor of the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) is a pool type reactor of B and W design, that has been operating since 1957 at a power of 2 MW. Irradiated (spent) fuels have been stored at the facility during the various years of operation. At present there are 40 spent fuel assemblies at dry storage, 79 spent fuel assemblies at wet storage and 30 fuel assemblies in the core. The oldest fuels are of United States origin, made with U-Al alloy, both of LEU and HEU MTR fuel type. Many of these fuel assemblies have corrosion pits along their lateral fuel plates. These pits originate by galvanic corrosion between the fuel plate and the stainless steel storage racks. As a consequence of the possibility of sending the irradiated old fuels back the U.S.A., sipping tests were performed with the spent fuel assemblies. The reason for this was to evaluate their 137 Cs leaking rate, if any. This work describes the procedure and methodology used to perform the sipping tests with the fuel assemblies at the storage pool, and presents the results obtained for the 137 Cs sipping water activity for each fuel assembly. A correlation is made between the corrosion pits and the activity values measured. A 137 Cs leaking rate is determined and compared to the criteria established for canning spent fuel assemblies before shipment

Open Pit Water Control Safety A Case Of Nchanga Open Pit Mine Zambia

OpenAIRE

Silwamba C; Chileshe P R K

2015-01-01

Abstract Mining in Chingola Zambia started underground in 1931 and was catastrophically flooded and closed. The present Nchanga Underground Mine NUG started in 1937. The Nchanga Open Pit NOP mine started in 1955 situated to the west of NUG and partially overlying it. Open pit water control safety operations in the Nchanga-Chingola area have successfully enabled the safe extraction of millions of tonnes of copper ore annually over the past 60 years from NUG mining as well as the NOP. At the st...

Investigating pitting in X65 carbon steel using potentiostatic polarisation

Science.gov (United States)

Mohammed, Sikiru; Hua, Yong; Barker, R.; Neville, A.

2017-11-01

Although pitting corrosion in passive materials is generally well understood, the growth of surface pits in actively-corroding materials has received much less attention to date and remains poorly understood. One of the key challenges which exists is repeatedly and reliably generating surface pits in a practical time-frame in the absence of deformation and/or residual stress so that studies on pit propagation and healing can be performed. Another pertinent issue is how to evaluate pitting while addressing general corrosion in low carbon steel. In this work, potentiostatic polarisation was employed to induce corrosion pits (free from deformation or residual stress) on actively corroding X65 carbon steel. The influence of applied potential (50 mV, 100 mV and 150 mV vs open circuit potential) was investigated over 24 h in a CO2-saturated, 3.5 wt.% NaCl solution at 30 °C and pH 3.8. Scanning electron microscopy (SEM) was utilised to examine pits, while surface profilometry was conducted to measure pit depth as a function of applied potential over the range considered. Analyses of light pitting (up to 120 μm) revealed that pit depth increased linearly with increase in applied potential. This paper relates total pit volume (measured using white light interferometry) to dissipated charge or total mass loss (using the current response for potentiostatic polarisation in conjunction with Faraday's law). By controlling the potential of the surface (anodic) the extent of pitting and general corrosion could be controlled. This allowed pits to be evaluated for their ability to continue to propagate after the potentiostatic technique was employed. Linear growth from a depth of 70 μm at pH 3.8, 80 °C was demonstrated. The technique offers promise for the study of inhibition of pitting.

Pitting of malaria parasites and spherocyte formation

Directory of Open Access Journals (Sweden)

Gichuki Charity W

2006-07-01

Full Text Available Abstract Background A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA but no intracellular parasites, support the idea of pitting. Methods An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide. Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive. Results Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% ± 1.31% macrophages with engulfed trophozoites as opposed to erythrophagocytosis (5.33% ± 0.95% (P Conclusion It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes.

Activity of some isoenzymatic systems in stored coffee grains

Directory of Open Access Journals (Sweden)

Reni Saath

2014-02-01

Full Text Available Considering the worldwide consumption of coffee, it is natural that throughout the history many people have dedicated the research to markers that contribute somehow on gauging its quality. This research aimed to evaluate the biochemical performance of arabica coffee during storage. Coffee in beans (natural and in parchment (pulped dried in concrete terrace and in dryer with heated air were packed in jute bags and stored in not controlled environmental conditions. Enzymatic activities of superoxide dismutase, catalase, peroxidase, polyphenoloxidase, esterase and lipoxygenase in coffee grains were evaluated at zero, three, six, nine and twelve months by means of electrophoresis. Independently of the drying method, the activity of isoenzymatic complexes highlighted deteriorative processes in stored grains of coffee. The treatments 60/40º C and 60º C used to reduce the water content imposed a greater stress condition, accelerated metabolism of natural coffee in the storage with decreased activity of defense mechanisms due to latent damage in these grains. Natural coffees are more sensible to high drying temperatures and its quality reduces faster than pulped coffee in the storage.

Relationship between fungal contamination and ergosterol content and control of wheat grain spoilage by gamma rays

International Nuclear Information System (INIS)

Shahin, A.M.; Mahrous, S.R.; Aziz, N.H.; El-Zeany, S.M.

2003-01-01

The fungal flora and the ergosterol content of wheat grains were determined and the effect of gamma-irradiation on some important grain fungi to control mould spoilage of wheat grains was also investigated. At the start of storage, the ergosterol content and the number of moulds of wheat grains were 3.3μg/g and 3x10 3 /g, respectively and the technological values as germinative capacity and fat acidity were wholly satisfactory. After 50 days of storage, the ergosterol content and the number of moulds of the grains were 45.5 μg/g and 80x10 5 /g, respectively and all the germinative capacity and fat acidity values were not satisfactory. The ergosterol content of wheat grains irradiated at a dose level 3 kGy was 0.5 μg/g and the number of moulds were 8x10 2 /g. After 50 days of storage, the ergosterol content of the 3 kGy irradiated grains was 0.90 μg/g and the number of moulds were 15x10 2 /g and all the technological values were satisfactory. The fungal biomass and the ergosterol content of some grains fungi were decreased by increasing the irradiation dose levels. At irradiation dose level 4 kGy, there was no ergosterol in wheat grains and the moulds were completely inhibited and the technological values are wholly satisfactory over 50 days of storage

Final environmental impact statement for the continued operation of the Pantex Plant and associated storage of nuclear weapon components. Volume 1 -- Main report

International Nuclear Information System (INIS)

1996-11-01

This document assesses the potential environmental impacts over approximately 10 years of continued operation of Pantex Plant, including foreseeable projects and activities. For Pantex Plant, this document assesses the alternatives of No Action, Relocation of the storage of plutonium components (pits) resulting from nuclear weapon disassembly activities at Pantex Plant to another site, and the Proposed Action (Preferred Alternative) of continuing operations and increasing the quantity of pits in interim storage at Pantex Plant. For the Pit Storage Relocation Alternative, this document also assesses the potential environmental impacts to three DOE candidate sites and one Department of Defense candidate site that could be selected for the relocation of the nuclear component storage activities from Pantex Plant. Evaluations of site infrastructure, land resources, geology and soils, water resources, air quality, acoustics, biotic resources, cultural resources, socio-economic resources, intrasite transportation, waste management, human health, aircraft accidents, and environmental justice for Pantex Plant and the candidate sites are included in the assessment. The intersite transportation of nuclear and hazardous materials is also assessed

Pitting corrosion of copper. An equilibrium - mass transport study

Energy Technology Data Exchange (ETDEWEB)

Taxen, C

1996-11-01

A mathematical model for the propagation of corrosion pits on copper is described. The model is used to predict the potentials below which copper is immune to pitting. The criteria used for immunity against pitting is that the volume of the cuprous oxide formed at the site of the metal oxidation at the bottom of a corrosion pit must be smaller than the volume of the oxidised metal. Equal volumes would give a complete coverage of the metal in a pit by adherent cuprous oxide and propagation would not be possible. For potentials where copper is not immune to pitting an estimate of the maximum growth rate is given. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles from the bulk water outside a corrosion pit to the site of the metal dissolution at the bottom a corrosion pit. Precipitation of oxides as well as of basic salts of copper is considered. A total of 26 aqueous species are considered in waters with compositions ranging from those of tap waters to that of sea water. Calculations are made for the temperatures 25 deg C and 75 deg C. 38 refs, 60 figs, 17 tabs

Research process of nondestructive testing pitting corrosion in metal material

Directory of Open Access Journals (Sweden)

Bo ZHANG

2017-12-01

Full Text Available Pitting corrosion directly affects the usability and service life of metal material, so the effective nondestructive testing and evaluation on pitting corrosion is of great significance for fatigue life prediction because of data supporting. The features of pitting corrosion are elaborated, and the relation between the pitting corrosion parameters and fatigue performance is pointed out. Through introducing the fundamental principles of pitting corrosion including mainly magnetic flux leakage inspection, pulsed eddy current and guided waves, the research status of nondestructive testing technology for pitting corrosion is summarized, and the key steps of nondestructive testing technologies are compared and analyzed from the theoretical model, signal processing to industrial applications. Based on the analysis of the signal processing specificity of different nondestructive testing technologies in detecting pitting corrosion, the visualization combined with image processing and signal analysis are indicated as the critical problems of accurate extraction of pitting defect information and quantitative characterization for pitting corrosion. The study on non-contact nondestructive testing technologies is important for improving the detection precision and its application in industries.

Triple bag hermetic technology for controlling a bruchid (Spermophagus sp.) (Coleoptera, Chrysomelidae) in stored Hibiscus sabdariffa grain.

Science.gov (United States)

Amadou, L; Baoua, I B; Baributsa, D; Williams, S B; Murdock, L L

2016-10-01

We assessed the performance of hermetic triple layer Purdue Improved Crop Storage (PICS) bags for protecting Hibiscus sabdariffa grain against storage insects. The major storage pest in the grain was a bruchid, Spermophagus sp.. When we stored infested H. sabdariffa grain for six months in the woven polypropylene bags typically used by farmers, the Spermophagus population increased 33-fold over that initially present. The mean number of emergence holes per 100 seeds increased from 3.3 holes to 35.4 holes during this time period, while grain held for the same length of time in PICS bags experienced no increase in the numbers of holes. Grain weight loss in the woven control bags was 8.6% while no weight loss was observed in the PICS bags. Seed germination rates of grain held in woven bags for six months dropped significantly while germination of grain held in PICS bags did not change from the initial value. PICS bags can be used to safely store Hibiscus grain after harvest to protect against a major insect pest.

The Study Related to the Execution of a Triangulation Network in the Dump of Rovinari Pit, in Order to be Restored to the Economic Circuit

Directory of Open Access Journals (Sweden)

George Popescu

2016-11-01

Full Text Available The lignite mining extraction within the mining perimeter in Rovinari is carried out through mining works in the open, by using large equipments for the excavation, transport and storage of the mining material. These surfaces are currently being set up in the area of level two of the dump, the west and north-west part of Rovinari pit. In order to carry out the set-up works and of follow-up of the stability of the pit levels it is necessary to maintain the triangulation network.

Spontaneous Resolution of Optic Disc Pit Maculopathy

OpenAIRE

Tripathy, Koushik

2017-01-01

I read with interest the article reporting spontaneous resolution of optic disc pit maculopathy in a boy.1 Though the presence of an optic disc pit and associated macular involvement is undoubted in the presented case, the provided optical coherence tomography (OCT) does not clearly show typical intraretinal schisis (Figure 1B)1 at multiple retinal levels which may communicate with the pit. Instead, it shows a sub-internal limiting membrane (sub-ILM) cavity. Such cavities are known to occur f...

In-service inspection of ET-RR-1 reactor vessels and spent fuel storage tank

International Nuclear Information System (INIS)

Khattab, M.; Shafy, M.; Konoplev, K.; Samodurve, YU.; Orlov, S.; Didenko, V.; Jackorev, O.

1993-01-01

Technical survey included in-service inspection are needed in order to investigate the structural integrity and to insure safe operation of the ET-R R-1 reactor after thirty years aging. An intensive work for the inspection of the inspection of the central tank, shield tank, horizontal channels, primary coolant circuit and spent fuel storage tank have been carried out. The inspection procedures were visual method using video camera and magnification optical as well as thickness measurements using ultrasonic gauge meter and replica for determining defect depth. Water chemical analysis of the primary cooling circuit and spent fuel storage were helpful in results explanation. The results showed that the reactor vessels have good surface conditions. The observed pitting did not affect the structural integrity. The majority of the defects were pits having maximum surface area of about 50 mm. Their depth does not exceed 2 mm. The pits depth rate penetration is of the order of 0.5% per year. Thickness measurements showed insignificant variation. Water status and its chemical properties are very important in controlling corrosion rate. 18 figs., 14 tabs

Partitioning of water between point defects, dislocations, and grain boundaries in olivine

Science.gov (United States)

Tielke, J. A.; Mecklenburgh, J.; Mariani, E.; Wheeler, J.

2017-12-01

Estimates of the storage capacity of water in the interior of the Earth and other terrestrial planets vary significantly. One interpretation is that water in planetary interiors exists primarily as hydrogen ions, dissociated from liquid water, that are associated with point defects in the crystal structure of nominally anhydrous minerals. However, dislocations and grain boundaries may contribute significantly to the storage capacity of water in planetary interiors, but hydrogen concentrations in dislocations and grain boundaries are difficult to quantify. To measure the water storage capacity of dislocations and grain boundaries, we are analyzing results from high-temperature and high-pressure experiments where deuterium, a stable isotope of hydrogen, was incorporated into olivine, the dominate phase in the upper mantle. Compared to hydrogen, deuterium concentrations can be determined at much higher spatial resolution using secondary-ion mass spectroscopy. The concentration of deuterium in the samples will also be quantified using Fourier transform infrared spectroscopy for comparison to results for hydrogen-bearing olivine. The spatial distribution of regions with different densities of geometrically-necessary dislocations and the locations of grain boundaries will be determined using electron-backscatter diffraction (EBSD) analyses. Correlation of the concentration of deuterium with dislocation densities and grain boundaries will be used to examine the partitioning of water-derived species between the different types of defects. Ultimately, these data will be used to place more realistic bounds on the storage capacity of water in the interior of Earth and of other terrestrial planets.

A decision support system for cost determination in grain storage facility operations Um sistema de apoio à decisão para determinação de tarifas em unidades armazenadoras de grãos

Directory of Open Access Journals (Sweden)

Domingos S. M. Valente

2011-01-01

Full Text Available Many research works have being carried out on analyzing grain storage facility costs; however a few of them had taken into account the analysis of factors associated to all pre-processing and storage steps. The objective of this work was to develop a decision support system for determining the grain storage facility costs and utilization fees in grain storage facilities. The data of a CONAB storage facility located in Ponta Grossa - PR, Brazil, was used as input of the system developed to analyze its specific characteristics, such as amount of product received and stored throughout the year, hourly capacity of drying, cleaning, and receiving, and dispatch. By applying the decision support system, it was observed that the reception and expedition costs were exponentially reduced as the turnover rate of the storage increased. The cleaning and drying costs increased linearly with grain initial moisture. The storage cost increased exponentially as the occupancy rate of the storage facility decreased.Vários trabalhos de análise de custos em unidades armazenadoras de produtos agrícolas foram conduzidos; no entanto, poucos abordam as análises dos efeitos dos fatores associados a cada uma das etapas do pré-processamento e armazenagem. Desse modo, o objetivo deste trabalho foi desenvolver um sistema de apoio à decisão para determinação de custos e tarifas em unidades armazenadoras de produtos agrícolas. Uma unidade da CONAB, localizada em Ponta Grossa - PR, foi usada para geração de resultados conforme suas características específicas, tais como quantidade de produto recebido e estocado ao longo do ano, capacidade horária de secagem, limpeza, recepção e expedição. Ao empregar o sistema de apoio à decisão, foi constatado que os custos de recepção e expedição diminuem exponencialmente com o aumento do índice de rotatividade da unidade armazenadora; que os custos de limpeza e secagem foram aproximadamente lineares e crescentes com

Kajian konsentrasi kefir grain dan lama simpan dalam refrigerator terhadap kualitas kimiawi kefir rendah lemak

Directory of Open Access Journals (Sweden)

Manik Eirry Sawitri

2012-03-01

Full Text Available Abstract : 1, 2percent (G2dan 3 percent (G3of milk volume and the second factor was storage time in refrigerator which were 0day(L0,7days(L7,14days(L14, 21 days(L21 and 28 days(L28 Keywords: kefir grains, storage time, refrigerator, low fat kefir . The variables measured were fat, protein, and alcohol content of kefir. Data were analyzed by analysis of variance and continued with Duncan. The results of research showed that concentration of kefir grains and storage time in refrigerator had highly significant effect (P0,05 on fat content of kefir. Interaction between both treatments had highly significant effect (P<0,01 on alcohol content of kefir. The conclusion of this research was apply 1 percent of kefir grains and maximum storage time in refrigerator for 21 days to produce kefir which appropriate with standard of fermentation milk. The objective of this research was to find out the influence of low fat milk in kefir processing with examined concentration on kefir grains and storage time in refrigerator to the fat, protein and alcohol content. This research was also to determined the concentration of kefir grains which appropriate to the standard of fermentation milk and as an information for practician and industry related to the research product. The materials used kefir that made from low fat milk (1% fat content, the research method was using Factorial Randomized Block Design (3X5. The first factor was concentration of kefir grains which were 1 percent(G

Grain refining effect of magnetic field on Mg2Ni0.8Mn0.2 hydrogen storage alloys during rapid quenching

International Nuclear Information System (INIS)

Jiang, Chenxi; Wang, Haiyan; Chen, Xiangrong; Tang, Yougen; Lu, Zhouguang; Wang, Yazhi; Liu, Zuming

2013-01-01

The effect of static magnetic field treatment for synthesis of Mg 2 Ni 0.8 Mn 0.2 alloys during rapid quenching was investigated in this paper. X-ray diffraction (XRD) and scanning electron microscope (SEM) results show that the transversal static magnetic field can effectively refine the grain size, producing nanocrystalline inside. This distinct phenomenon is probably attributed to the Lorentz force suppressing the crystallization of the hydrogen storage alloys and the thermoelectric effect. Mainly due to the grain refinement, the discharge capacity of Mg 2 Ni 0.8 Mn 0.2 alloy is raised from 79 to about 200 mA h g −1 . It is confirmed that Mg 2 Ni 0.8 Mn 0.2 alloy by magnetic field assisted approach possesses enhanced electrochemical kinetics and relatively high corrosion resistance against the alkaline solution, thus resulting in higher electrochemical properties

A model of the dose rate calculation for a spent fuel storage structure by Monte Carlo method using the modulated code system SCALE 4.4a

International Nuclear Information System (INIS)

Pantazi, D.; Mateescu, S.; Stanciu, M.; Mete, M.

2001-01-01

The modulated code system SCALE is used to perform a standardized shielding analysis for any facility containing spent fuel: handling devices, transport cask, intermediate and final storage facility. The neutron and gamma sources as well as the dose rates can be obtained using either discrete-ordinates or Monte Carlo methods. The shielding analysis control modules (SAS1, SAS2H and SAS4) provide a general procedure for cross-section preparation, fuel depletion/decay calculation and general onedimensional or multi-dimensional shielding analysis. The module SAS4 used in the analysis presented in this paper, is a three-dimensional Monte Carlo shielding analysis module, which uses an automated biasing procedure specialized for a nuclear fuel transport or storage container. The Spent Fuel Interim Storage Facility in our country is projected to be a parallelepiped concrete monolithic module, consisting of an external reinforced concrete structure with vertical storage cylinders (pits) arranged in a rectangular array. A pit is filled with sealed cylindrical baskets of stainless steel arranged in a stack, and with each basket containing spent fuel bundles in vertical position. The pit is closed with a concrete plug. The cylindrical geometry model is used in the shielding evaluation for a spent fuel storage structure (pit), and only the active parts of the superposed bundles is considered. The dose rates have been calculated in both the axial and radial directions using SAS4.(author)

Modelling assessment of End Pit Lakes meromictic potential

International Nuclear Information System (INIS)

2006-11-01

The use of End Pit Lakes have been proposed as a remediation solution for oil sands reclamation and operational waters. This report modelled the main factors controlling the occurrence of stratification in Pit Lakes in order to establish design and management guidelines for the Cumulative Environmental Management Association's End Pit Lake Sub-group. The study focused on End Pit Lake size, depth, starting lake salinity concentrations, inflow rates and inflow salinity flux, and investigated their influence on density gradients. One-dimensional modelling and limited 2-D modelling simulations were conducted to examine meromictic potential for a large range of End Pit Lake configurations and conditions. Modelling results showed that fall is the governing season for determining meromixis. The expelling of salt from saline water upon ice formation and its effect on stratification potential and the effect of fresh water loading on stratification potential during spring melt events were not observed to be dominant factors governing meromictic potential for the scenarios examined in the study. Results suggested that shallow End Pit Lakes showed a high turn-over rate with seasonal heating and cooling cycles. Moderately deep End Pit Lakes demonstrated a meromictic potential that was inversely proportional to lake size and require higher starting salinities. With a 2 or 10 million m 3 /yr inflow rate and a 5 parts per thousand starting salinity, a 50 m deep End Pit Lake achieved meromixis at all 3 size ranges considered in the study. Results also showed that the rate of influent salinity decrease was the least important of the parameters influencing meromixis. It was observed that meromixis was a temporary condition in all of the End Pit Lake scenarios envisioned due to the lack of a constant, positive salt replenishment over the long term. It was concluded that further 3-D modelling is required to represent littoral areas as well as to account for extreme winter conditions. A

Production of aflatexin B1 in wheat grains under different environmental storage conditions

International Nuclear Information System (INIS)

Mahrous, S.R.; Shahin, A.A.M.; Bothaina, M.Y.

2000-01-01

Fungal flora of stored wheat grains and the production of aflatoxin B 1 by Aflavus in wheat grains under different environmental conditions were examined. Aspergillus, Penicillium,. Fusarium, Cladosporium, Curvularia, Epicouccum, Verticilium, Rhizopus, Mucor and Altenaria were the predominant fungi isolated from the collected non-disinfected grains. Aspergillus spp, were only isolated from surface disinfected grains. Of 223 aspergillus spp, isolates only 128 found to aflatoxin producing and all aflatoxin producing-fungi belonged to the Aflavus group. Results demonstrate that Aflavus could produce maximum concentration of aflatoxin B 1 in grains at 20% moisture (163.5 MOU g/kg). The highest concentration of aflatoxin B 1 was produced by Aflavus (10 5 spores/g) in wheat grains with 20% moisture after 20 days at 30 degree and 92.40 % R.H. The aflatoxin production did not increase monotonously as a function of inoculum density

Pit Study, Geographic NAD83, LOSCO (1999) [pit_study_LOSCO_1998

Data.gov (United States)

Louisiana Geographic Information Center — The 'Pit Study' was meant to identify the remnants of former oil extraction sites which pose the threat of creating an oil spill. These remnants include many other...

Grain bulk density measurement based on wireless network

Directory of Open Access Journals (Sweden)

Wu Fangming

2017-01-01

Full Text Available To know the accurate quantity of stored grain, grain density sensors must be used to measure the grain’s bulk density. However, multi-sensors should be inserted into the storage facility, to quickly collect data during the inventory checking of stored grain. In this study, the ZigBee and Wi-Fi coexistence network’s ability to transmit data collected by density sensors was investigated. A system consisting of six sensor nodes, six router nodes, one gateway and one Android Pad was assembled to measure the grain’s bulk density and calculate its quantity. The CC2530 chip with ZigBee technology was considered as the core of the information processing, and wireless nodes detection in sensor, and router nodes. ZigBee worked in difference signal channel with Wi-Fi to avoid interferences and connected with Wi-Fi module by UART serial communications interfaces in gateway. The Android Pad received the measured data through the gateway and processed this data to calculate quantity. The system enabled multi-point and real-time parameter detection inside the grain storage. Results show that the system has characteristics of good expansibility, networking flexibility and convenience.

Markov chain modelling of pitting corrosion in underground pipelines

Energy Technology Data Exchange (ETDEWEB)

Caleyo, F. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico)], E-mail: fcaleyo@gmail.com; Velazquez, J.C. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico); Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400 La Habana (Cuba); Hallen, J.M. [Departamento de Ingenieri' a Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, Mexico D. F. 07738 (Mexico)

2009-09-15

A continuous-time, non-homogenous linear growth (pure birth) Markov process has been used to model external pitting corrosion in underground pipelines. The closed form solution of Kolmogorov's forward equations for this type of Markov process is used to describe the transition probability function in a discrete pit depth space. The identification of the transition probability function can be achieved by correlating the stochastic pit depth mean with the deterministic mean obtained experimentally. Monte-Carlo simulations previously reported have been used to predict the time evolution of the mean value of the pit depth distribution for different soil textural classes. The simulated distributions have been used to create an empirical Markov chain-based stochastic model for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil. The proposed model has also been applied to pitting corrosion data from pipeline repeated in-line inspections and laboratory immersion experiments.

Markov chain modelling of pitting corrosion in underground pipelines

International Nuclear Information System (INIS)

Caleyo, F.; Velazquez, J.C.; Valor, A.; Hallen, J.M.

2009-01-01

A continuous-time, non-homogenous linear growth (pure birth) Markov process has been used to model external pitting corrosion in underground pipelines. The closed form solution of Kolmogorov's forward equations for this type of Markov process is used to describe the transition probability function in a discrete pit depth space. The identification of the transition probability function can be achieved by correlating the stochastic pit depth mean with the deterministic mean obtained experimentally. Monte-Carlo simulations previously reported have been used to predict the time evolution of the mean value of the pit depth distribution for different soil textural classes. The simulated distributions have been used to create an empirical Markov chain-based stochastic model for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil. The proposed model has also been applied to pitting corrosion data from pipeline repeated in-line inspections and laboratory immersion experiments.

Force-displacement measurements of earlywood bordered pits using a mesomechanical tester.

Science.gov (United States)

Zelinka, Samuel L; Bourne, Keith J; Hermanson, John C; Glass, Samuel V; Costa, Adriana; Wiedenhoeft, Alex C

2015-10-01

The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force-displacement measurements for pit membranes of circular bordered pits, collected on a mesomechanical testing system. The system consists of a quartz microprobe attached to a microforce sensor that is positioned and advanced with a micromanipulator mounted on an inverted microscope. Membrane displacement is measured from digital image analysis. Unaspirated pits from earlywood of never-dried wood of Larix and Pinus and aspirated pits from earlywood of dried wood of Larix were tested to generate force-displacement curves up to the point of membrane failure. Two failure modes were observed: rupture or tearing of the pit membrane by the microprobe tip, and the stretching of the pit membrane until the torus was forced out of the pit chamber through the pit aperture without rupture, a condition we refer to as torus prolapse. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Intermediate storage facility for vitrified high level waste from the reprocessing of spent nuclear fuel

International Nuclear Information System (INIS)

1978-04-01

An intermediate storage facility for vitrified high level waste is described. The design was made specifically for Swedish conditions but can due to modular design be applied also for other conditions. Most of the plant is located underground with a rock cover of about 30 m in order to provide protection against external forces such as acts of war and sabotage. The storage area consists of four caverns each with 150 pits. Each pit can take 10 waste cylinders of 0.4 m diameter and 1.5 m length containing 150 liters of glass. The capacity can be increased by adding additional caverns. Cooling is obtained by forced air convection. Reception areas, auxiliary systems and operation of the plant are also described

Corrosion of assemblies in fuel-storage basins at Savannah River Plant

International Nuclear Information System (INIS)

Wollam, C.D.

1980-09-01

Pitting of reactor assemblies has been the major corrosion problem in the Savannah River Plant fuel storage basins. From 1972 to 1976 many reactor assemblies experienced severe pitting corrosion with rates up to 9.3 mm/y. Poor cladding, high concentrations of iron and chloride ions in the water, a galvanic couple between the aluminum clad assemblies and the stainless steel hangers, and scratches in the oxide layer on assemblies have been identified as contributors to the problem. This paper describes the examinations and tests that were conducted and discusses a theory that explains the observed phenomena

Inconsistent identification of pit bull-type dogs by shelter staff.

Science.gov (United States)

Olson, K R; Levy, J K; Norby, B; Crandall, M M; Broadhurst, J E; Jacks, S; Barton, R C; Zimmerman, M S

2015-11-01

Shelter staff and veterinarians routinely make subjective dog breed identification based on appearance, but their accuracy regarding pit bull-type breeds is unknown. The purpose of this study was to measure agreement among shelter staff in assigning pit bull-type breed designations to shelter dogs and to compare breed assignments with DNA breed signatures. In this prospective cross-sectional study, four staff members at each of four different shelters recorded their suspected breed(s) for 30 dogs; there was a total of 16 breed assessors and 120 dogs. The terms American pit bull terrier, American Staffordshire terrier, Staffordshire bull terrier, pit bull, and their mixes were included in the study definition of 'pit bull-type breeds.' Using visual identification only, the median inter-observer agreements and kappa values in pair-wise comparisons of each of the staff breed assignments for pit bull-type breed vs. not pit bull-type breed ranged from 76% to 83% and from 0.44 to 0.52 (moderate agreement), respectively. Whole blood was submitted to a commercial DNA testing laboratory for breed identification. Whereas DNA breed signatures identified only 25 dogs (21%) as pit bull-type, shelter staff collectively identified 62 (52%) dogs as pit bull-type. Agreement between visual and DNA-based breed assignments varied among individuals, with sensitivity for pit bull-type identification ranging from 33% to 75% and specificity ranging from 52% to 100%. The median kappa value for inter-observer agreement with DNA results at each shelter ranged from 0.1 to 0.48 (poor to moderate). Lack of consistency among shelter staff indicated that visual identification of pit bull-type dogs was unreliable. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Sustainable Environmental Protection Using Modified Pit-Latrines

NARCIS (Netherlands)

Chaggu, E.J.

2004-01-01

Pit-latrines are on-site excreta disposal facilities widely used as anaerobic accumulation system for stabilizing human wastes like excreta, both in rural and urban settlements of developing countries. Flooding of pit-latrines is often a common phenomenon, especially in situations of high water

Pitting corrosion of copper. An equilibrium - mass transport study

International Nuclear Information System (INIS)

Taxen, C.

2002-08-01

A mathematical model for the propagation of corrosion pits is described and used to calculate the potentials below which copper is immune to pitting. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles of 26 aqueous species from the bulk water outside a corrosion pit to the site of the metal dissolution. Precipitation of oxides and salts of copper is considered. Studied conditions include water compositions from tap waters to seawater at the temperatures 25 deg C and 75 deg C. Carbonate and sulphate are aggressive towards copper because of complex formation with divalent copper. Carbonate is less aggressive in a corrosion pit than outside at the pH of the bulk. Carbonate carries acidity out from the pit, favours oxide formation and may prevent the initiation of acidic corrosion pits. The concentration profiles are used to estimate the maximum propagation rates for a corrosion pit. A high potential is found to be the most important factor for the rate of propagation. The levels of potential copper can sustain, as corrosion potentials are discussed in terms of the stability of cuprous oxide as a cathode material for oxygen reduction relative to non-conducting cupric phases

Pitting corrosion of copper. An equilibrium - mass transport study

Energy Technology Data Exchange (ETDEWEB)

Taxen, C. [Swedish Corrosion Inst., Stockholm (Sweden)

2002-08-01

A mathematical model for the propagation of corrosion pits is described and used to calculate the potentials below which copper is immune to pitting. The model uses equilibrium data and diffusion coefficients and calculates the stationary concentration profiles of 26 aqueous species from the bulk water outside a corrosion pit to the site of the metal dissolution. Precipitation of oxides and salts of copper is considered. Studied conditions include water compositions from tap waters to seawater at the temperatures 25 deg C and 75 deg C. Carbonate and sulphate are aggressive towards copper because of complex formation with divalent copper. Carbonate is less aggressive in a corrosion pit than outside at the pH of the bulk. Carbonate carries acidity out from the pit, favours oxide formation and may prevent the initiation of acidic corrosion pits. The concentration profiles are used to estimate the maximum propagation rates for a corrosion pit. A high potential is found to be the most important factor for the rate of propagation. The levels of potential copper can sustain, as corrosion potentials are discussed in terms of the stability of cuprous oxide as a cathode material for oxygen reduction relative to non-conducting cupric phases.

Film Grain-Size Related Long-Term Stability of Inverted Perovskite Solar Cells.

Science.gov (United States)

Chiang, Chien-Hung; Wu, Chun-Guey

2016-09-22

The power conversion efficiency (PCE) of the perovskite solar cell is high enough to be commercially viable. The next important issue is the stability of the device. This article discusses the effect of the perovskite grain-size on the long-term stability of inverted perovskite solar cells. Perovskite films composed of various sizes of grains were prepared by controlling the solvent annealing time. The grain-size related stability of the inverted cells was investigated both in ambient atmosphere at relative humidity of approximately 30-40 % and in a nitrogen filled glove box (H 2 Operovskite film having the grain size larger than 1 μm (D-10) decreases less than 10 % with storage in a glove box and less than 15 % when it was stored under an ambient atmosphere for 30 days. However, the cell using the perovskite film composed of small (∼100 nm) perovskite grains (D-0) exhibits complete loss of PCE after storage under the ambient atmosphere for only 15 days and a PCE loss of up to 70 % with storage in the glove box for 30 days. These results suggest that, even under H 2 O-free conditions, the chemical- and thermal-induced production of pin holes at the grain boundaries of the perovskite film could be the reason for long-term instability of inverted perovskite solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A predictive approach to fitness-for-service assessment of pitting corrosion

International Nuclear Information System (INIS)

Shekari, Elahe; Khan, Faisal; Ahmed, Salim

2016-01-01

Pitting corrosion is a localized corrosion that often causes leak and failure of process components. The aim of this work is to present a new fitness-for-service (FFS) assessment methodology for process equipment to track and predict pitting corrosion. In this methodology, pit density is modeled using a non-homogenous Poisson process and induction time for pit initiation is simulated as the realization of a Weibull process. The non-homogenous Markov process is used to estimate maximum pit depth, considering that only the current state of the damage influences its future development. Subsequently, the distributions of the operating pressure and the estimated burst pressure of the defected component are integrated with Monte Carlo simulations and First Order Second Moment (FOSM) method to calculate the reliability index and probability of failure. This methodology provides a more realistic failure assessment and enables consideration of uncertainty associated with estimating pit characteristics. The practical application of the proposed model is demonstrated using a piping case study. - Highlights: • A new model to estimate maximum pit depth and pit density as two main pit characteristics. • Integrating maximum pit depth with failure analysis considering allowable pressure of defected component. • Time dependent failure analysis to determine the remaining life.

Least tern and piping plover nesting at sand pits in Nebraska

Science.gov (United States)

Sidle, John G.; Kirsch, E.M.

1993-01-01

Endangered Least Terns (Sterna antillarum) and threatened Piping Plovers (Charadrius melodus) nest at commercial sand and gravel mining operations (sand pits) along the Platte River system in Nebraska. Sandbar habitat has been disappearing since the early 1900's along the Platte River system, but numbers of sand pits have increased. We hypothesized that birds would more fully utilize sand pits where suitable sandbar habitat was limited. We inventoried sand pits and censused terns and plovers on both habitats along the Loup River, part of the North Loup River, and most of the Platte River during 1988-1991. Using aircraft, we also quantified features of suitable sand pits present on the central Platte in 1988 and lower Platte in 1990, and related features to abundance and presence of birds. We found 225 sand pits of which 78 were suitable and 187 were unsuitable for nesting. Along the central Platte, where sandbar habitat is severely degraded, birds nested at 81% of the suitable sand pits (N = 32) at least once during 1988-1991, and most birds (61-94%) nested on sand pits. Along the lower Platte, where both sandbar and sand pit habitat are plentiful, birds nested at 60% of the suitable sand pits (N = 35) at least once during 1988-1991, and most birds (60-86%) nested on sandbars. Numbers of terns and plovers were more weakly correlated with features of sand pits on the central Platte than on the lower Platte. Least Terns and Piping Plovers seem to use more of the suitable sand pit habitat on the central Platte than on the lower Platte. Sand pits probably have influenced the birds' distribution by providing alternative nesting habitat along rivers where suitable sandbars are rare or absent.

Composição mineral e severidade de "bitter pit" em maçãs 'Catarina' Mineral composition and bitter pit severity in 'Catarina' apples

Directory of Open Access Journals (Sweden)

Cassandro Vidal Talamini do Amarante

2006-04-01

Full Text Available Maçãs 'Catarina', colhidas na maturação comercial em pomar no município de São Joaquim-SC, foram separadas em quatro lotes de 14 frutos, de acordo com a severidade de incidência de "bitter pit": nula (nenhuma lesão/fruto, baixa (1-2 lesões/fruto, moderada (3-5 lesões/fruto e alta (6-18 lesões/fruto. Foram determinadas as concentrações de Ca, Mg, K e N na casca e na polpa de cada fruto. Foram verificadas relação linear (P 'Catarina' apples were harvested at the commercial maturity in an orchard in São Joaquim-SC and segregated in four lots of 14 fruits with different levels of bitter pit severity: null (none pit/fruit, low (1-2 pits/fruit, moderate (3-5 pits/fruit, and high (6-18 pits/fruit. Nutritional analysis (Ca, Mg, K, and N in the skin and flesh tissues were performed on individual fruits of each severity level. The average number of pits/fruit (calculated for each lot of bitter pit severity showed a negative linear relationship (P < 0.05 with the skin Ca content, and a negative linear relationship (P < 0.05 with the ratios of Mg/Ca, (K+Mg/Ca, and (K+Mg+N/Ca in the skin. For the flesh, the increasing of bitter pit severity was accompanied by significant reduction of Ca and Mg contents. The multivariate analysis (canonical discriminant analysis showed that the Mg/Ca ratio in the skin provided the best discrimination between the lots of fruit with different levels of bitter pit severity. Therefore, for 'Catarina' apples, increasing values of the Mg/Ca ratio in the skin are indicative of fruits with increasing bitter pit susceptibility.

Criteria for Corrosion Protection of Aluminum-Clad Spent Nuclear Fuel in Interim Wet Storage

International Nuclear Information System (INIS)

Howell, J.P.

1999-01-01

Storage of aluminum-clad spent nuclear fuel at the Savannah River Site (SRS) and other locations in the U. S. and around the world has been a concern over the past decade because of the long time interim storage requirements in water. Pitting corrosion of production aluminum-clad fuel in the early 1990''s at SRS was attributed to less than optimum quality water and corrective action taken has resulted in no new pitting since 1994. The knowledge gained from the corrosion surveillance testing and other investigations at SRS over the past 8 years has provided an insight into factors affecting the corrosion of aluminum in relatively high purity water. This paper reviews some of the early corrosion issues related to aluminum-clad spent fuel at SRS, including fundamentals for corrosion of aluminum alloys. It updates and summarizes the corrosion surveillance activities supporting the future storage of over 15,000 research reactor fuel assemblies from countries over the world during the next 15-20 years. Criteria are presented for providing corrosion protection for aluminum-clad spent fuel in interim storage during the next few decades while plans are developed for a more permanent disposition

Deterministic chaos in the pitting phenomena of passivable alloys

International Nuclear Information System (INIS)

Hoerle, Stephane

1998-01-01

It was shown that electrochemical noise recorded in stable pitting conditions exhibits deterministic (even chaotic) features. The occurrence of deterministic behaviors depend on the material/solution severity. Thus, electrolyte composition ([Cl - ]/[NO 3 - ] ratio, pH), passive film thickness or alloy composition can change the deterministic features. Only one pit is sufficient to observe deterministic behaviors. The electrochemical noise signals are non-stationary, which is a hint of a change with time in the pit behavior (propagation speed or mean). Modifications of electrolyte composition reveals transitions between random and deterministic behaviors. Spontaneous transitions between deterministic behaviors of different features (bifurcation) are also evidenced. Such bifurcations enlighten various routes to chaos. The routes to chaos and the features of chaotic signals allow to suggest the modeling (continuous and discontinuous models are proposed) of the electrochemical mechanisms inside a pit, that describe quite well the experimental behaviors and the effect of the various parameters. The analysis of the chaotic behaviors of a pit leads to a better understanding of propagation mechanisms and give tools for pit monitoring. (author) [fr

Dependence of corrosion properties of AISI 304L stainless steel on the austenite grain size

Energy Technology Data Exchange (ETDEWEB)

Sabooni, Soheil; Rashtchi, Hamed; Eslami, Abdoulmajid; Karimzadeh, Fathallah; Enayati, Mohammad Hossein; Raeissi, Keyvan; Imani, Reihane Faghih [Isfahan Univ. of Technology, Isfahan (Iran, Islamic Republic of). Dept. of Materials Engineering; Ngan, Alfonso Hing Wan [The Univ. of Hong Kong (China). Dept. of Mechanical Engineering

2017-07-15

The corrosion resistance of austenitic stainless steels is known to be hampered by the loss of chromium available for passive surface layer formation as a result of chromium carbide precipitation at austenite grain boundaries during annealing treatments. Although high-temperature annealing can promote carbide dissolution leading to better corrosion resistance, grain coarsening also results, which would lead to poorer mechanical properties. Processing methods to achieve both good corrosion resistance and mechanical properties are thus highly desirable for austenitic stainless steels. In the present study, we show that the corrosion resistance of AISI 304L stainless steel can be improved by grain refinement into the ultrafine-grained regime. Specifically, samples with different austenite grain sizes in the range of 0.65-12 μm were studied by potentiodynamic polarization and electrochemical impedance spectroscopy tests in a 3.5 wt.% NaCl solution. All samples showed a typical passive behavior with similar corrosion potential, but the corrosion current density decreased significantly with decreasing grain size. The results show that the sample with the finest grain size had the best corrosion resistance due to a higher resistance of the passive layer to pitting attacks. This study indicates that grain refinement which improves mechanical properties can also significantly improve the corrosion resistance of AISI 304L stainless steel.

Spontaneous Resolution of Optic Disc Pit Maculopathy

Directory of Open Access Journals (Sweden)

Koushik Tripathy

2017-06-01

Full Text Available I read with interest the article reporting spontaneous resolution of optic disc pit maculopathy in a boy.1 Though the presence of an optic disc pit and associated macular involvement is undoubted in the presented case, the provided optical coherence tomography (OCT does not clearly show typical intraretinal schisis (Figure 1B1 at multiple retinal levels which may communicate with the pit. Instead, it shows a sub-internal limiting membrane (sub-ILM cavity. Such cavities are known to occur following the resolution of sub-ILM bleed due to various cause including Valsalva retinopathy,2 Terson syndrome, and also in some retinitis3 cases.4 In fact, some of these cavities may simulate a neurosensory retinal detachment or central serous chorioretinopathy on cursory clinical examination.5 To confirm that the features of the current patient1 are indeed related to the optic disc pit, it is necessary for the authors to provide an OCT scan which shows a connection of the presented cavity with the optic disc pit. Also, clear OCT scans of the fovea, both at presentation and at final follow-up would help our understanding of the visual recovery of the patient. The interval between the presenting (28 June 2012 OCT and final OCT (30 Nov 2012 is 5 months and not 6 months as described in the manuscript. For an effective comparison, both the presenting and final OCT scans should have been taken using either horizontal or vertical orientation over the macula. Though the spontaneous resolution of optic disc pit maculopathy is possible, visual recovery in usually unlikely and in such cases an alternate diagnosis needs to be excluded.

Investigation of Stress Concentration and Casing Strength Degradation Caused by Corrosion Pits

Directory of Open Access Journals (Sweden)

Wei Yan

2016-01-01

Full Text Available Downhole casing and tubing are subjected to corrosion in many cases because of the exposure to corrosive environment. A more serious problem is that pitting corrosion occurs in the casing inner surface. Meanwhile, downhole strings are subjected to various forms of mechanical loads, for example, internal pressure load, external collapse load, or both. These loads acting on the corrosion pits will cause stress concentration and degrade the casing strength. Thus, it is essential to evaluate the stress concentration degree reasonably. The SCF (stress concentration factor is usually used to characterize the degree of stress concentration induced by corrosion pits. This paper presented a comparison on the SCFs regarding the analytical method for a single pit and experimental method for double pits. The results show that the SCF of a single pit depends mainly on the depth of the corrosion pit; however, the SCF of the double pits strongly depends on the pits distance. A correction factor of 1.3 was recommended in the double pits SCF prediction model.

Speed, Acceleration, Chameleons and Cherry Pit Projectiles

Science.gov (United States)

Planinsic, Gorazd; Likar, Andrej

2012-01-01

The paper describes the mechanics of cherry pit projectiles and ends with showing the similarity between cherry pit launching and chameleon tongue projecting mechanisms. The whole story is written as an investigation, following steps that resemble those typically taken by scientists and can therefore serve as an illustration of scientific…

The role of inclusions in the pitting behaviour of maraging steel

International Nuclear Information System (INIS)

Ahmad, M.S.; Hussain, S.W.; Ashraf, H.

1999-01-01

The pitting characteristics of maraging steel in artificial seawater have been investigated electrochemically using the cyclic polarization technique. Pits were found to be associated with the inclusions present in steel. The hysteresis loop observed indicates that maraging steel has poor resistance to pitting in air saturated seawater. On examination of corroded surfaces under SEM, it is noted that the pits are always associated with inclusions, which are generally the carbonitrides of TiMo presents in maraging steel in varying quantities depending on the melting practice. In order to confirm that the pitting behavior is associated with inclusions, samples from clean maraging steel, having very low inclusion level, were tested. Such samples showed much less tendency for pitting. (author)

Studies on microstructure, mechanical and pitting corrosion behaviour of similar and dissimilar stainless steel gas tungsten arc welds

Science.gov (United States)

Mohammed, Raffi; Dilkush; Srinivasa Rao, K.; Madhusudhan Reddy, G.

2018-03-01

In the present study, an attempt has been made to weld dissimilar alloys of 5mm thick plates i.e., austenitic stainless steel (316L) and duplex stainless steel (2205) and compared with that of similar welds. Welds are made with conventional gas tungsten arc welding (GTAW) process with two different filler wires namely i.e., 309L and 2209. Welds were characterized using optical microscopy to observe the microstructural changes and correlate with mechanical properties using hardness, tensile and impact testing. Potentio-dynamic polarization studies were carried out to observe the pitting corrosion behaviour in different regions of the welds. Results of the present study established that change in filler wire composition resulted in microstructural variation in all the welds with different morphology of ferrite and austenite. Welds made with 2209 filler showed plate like widmanstatten austenite (WA) nucleated at grain boundaries. Compared to similar stainless steel welds inferior mechanical properties was observed in dissimilar stainless steel welds. Pitting corrosion resistance is observed to be low for dissimilar stainless steel welds when compared to similar stainless steel welds. Overall study showed that similar duplex stainless steel welds having favorable microstructure and resulted in better mechanical properties and corrosion resistance. Relatively dissimilar stainless steel welds made with 309L filler obtained optimum combination of mechanical properties and pitting corrosion resistance when compared to 2209 filler and is recommended for industrial practice.

Force-displacement measurements of earlywood bordered pits using a mesomechanical tester

Science.gov (United States)

Samuel L. Zelinka; Keith J. Bourne; John C. Hermanson; Samuel V. Glass; Adriana Costa; Alex C. Wiedenhoeft

2015-01-01

The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force–displacement measurements for pit membranes of circular bordered pits, collected on a...

Investigating oiled birds from oil field waste pits

International Nuclear Information System (INIS)

Gregory, D.G.; Edwards, W.C.

1991-01-01

Procedures and results of investigations concerning the oiling of inland raptors, migratory water-fowl and other birds are presented. Freon washings from the oiled birds and oil from the pits were analyzed by gas chromatography. In most instances the source of the oil could be established by chromatographic procedures. The numbers of birds involved (including many on the endangered species list) suggested the need for netting or closing oil field waste pits and mud disposal pits. Maintaining a proper chain of custody was important

Some questions on small uranium open-pit mines

International Nuclear Information System (INIS)

Li Junyi

1992-01-01

The experiences of the existing uranium open pits are summarized and the questions in design, erection and production are analyzed. It is important helpful to develop and to design such economical and reasonable small uranium open pits

Mudstone depressurization behaviour in an open pit coal mine, Indonesia

Energy Technology Data Exchange (ETDEWEB)

Marchand, G.; Waterhouse, J. [Golder Associates, West Perth, WA (Australia); Crisostomo, J. [PT Adaro Indonesia, Jakarta (Indonesia)

2010-07-01

Mining activities in the Tutupan mine in Indonesia began in the mid-1990s. The open pit mine's coal seams are interbedded with fine-grained sandstones, mudstones, and carbonaceous mudstones. Slope stability analyses at the pit have integrated hydrogeology with geotechnical engineering analyses to optimize slope designs and reduce the risk of slope failure. This paper discussed the impact of mining and dewatering on mudstone depressurization. Sensors were placed at key points in the mine to obtain data related to the mudstone units. Reductions in pore pressure occurred as a result of groundwater flow away from the observed zones, increases in porosity, and increases in total porosity caused by an expansion of the rock mass as a result of drainage and hydrostatic unloading. Mudstone pore pressure trends with time were interpreted by determining the thickness of the mudstone unit, the presence or absence of known thin sandstone beds, unloading from overhead mining activities, and the position of the mudstone within the sedimentary sequence. The study showed that unloading activities have a significant impact on pore pressure in thick mudstone units, regardless of the depth, thickness, or properties of the unit. Pore pressure within high wall mudstone units typically decreased to values equivalent to the elevation of the unit where it was exposed to dips in a high wall. The dewatering of sandstone units in low walls caused a decline in pore pressure within the thick mudstone units located beneath the sandstones. Differences in primary permeabilities were attributed to greater fracturing in deeper and stronger rock units. 3 refs., 4 figs.

Water and chemical budgets of gravel pit lakes : Case studies of fluvial gravel pit lakes along the Meuse River (The Netherlands) and coastal gravel pit lakes along the Adriatic Sea (Ravenna, Italy)

NARCIS (Netherlands)

Mollema, P.N.

2016-01-01

Gravel pit lakes form when gravel is excavated from below the water table of a phreatic or shallow confined aquifer. Typically many of these lakes are concentrated along naturally occurring sedimentary gravel deposits in areas where gravel is needed for construction. Most gravel pit lakes are

Stochastic models for predicting pitting corrosion damage of HLRW containers

International Nuclear Information System (INIS)

Henshall, G.A.

1991-10-01

Stochastic models for predicting aqueous pitting corrosion damage of high-level radioactive-waste containers are described. These models could be used to predict the time required for the first pit to penetrate a container and the increase in the number of breaches at later times, both of which would be useful in the repository system performance analysis. Monte Carlo implementations of the stochastic models are described, and predictions of induction time, survival probability and pit depth distributions are presented. These results suggest that the pit nucleation probability decreases with exposure time and that pit growth may be a stochastic process. The advantages and disadvantages of the stochastic approach, methods for modeling the effects of environment, and plans for future work are discussed

A Bayesian approach to modeling and predicting pitting flaws in steam generator tubes

International Nuclear Information System (INIS)

Yuan, X.-X.; Mao, D.; Pandey, M.D.

2009-01-01

Steam generators in nuclear power plants have experienced varying degrees of under-deposit pitting corrosion. A probabilistic model to accurately predict pitting damage is necessary for effective life-cycle management of steam generators. This paper presents an advanced probabilistic model of pitting corrosion characterizing the inherent randomness of the pitting process and measurement uncertainties of the in-service inspection (ISI) data obtained from eddy current (EC) inspections. A Markov chain Monte Carlo simulation-based Bayesian method, enhanced by a data augmentation technique, is developed for estimating the model parameters. The proposed model is able to predict the actual pit number, the actual pit depth as well as the maximum pit depth, which is the main interest of the pitting corrosion model. The study also reveals the significance of inspection uncertainties in the modeling of pitting flaws using the ISI data: Without considering the probability-of-detection issues and measurement errors, the leakage risk resulted from the pitting corrosion would be under-estimated, despite the fact that the actual pit depth would usually be over-estimated.

Tale of two pit lakes: initial results of a three-year study of the Main Zone and Waterline pit lakes near Houston, British Columbia, Canada

Science.gov (United States)

Crusius, John; Pieters, R.; Leung, A.; Whittle, P.; Pedersen, T.; Lawrence, G.; McNee, J.J.

2003-01-01

Pit lakes are becoming increasingly common in North America as well as in the rest of the world. They are created as openpit mines fill passively with ground water and surface inflows on cessation of mining activity. In many instances, the water quality in these pit lakes does not meet regulatory requirements due to a number of influences. The most important are the oxidation of sulfide minerals and the associated release of acid and metals and the flushing of soluble metals during pit filling. Examples of pit lakes with severe water-quality problems include the Berkeley Pit lake (Butte, MT) and the Liberty Pit lake (Nevada), whose waters are characterized by a pH near 3 and Cu concentrations as high as ~150 mg/L (Miller et al., 1996; Davis and Eary, 1997). The importance of the problem can be seen in the fact that some of these sites in the United States are Superfund sites.

Particle Size (Sieving) and Enthalpy (Acid Calorimetry) Analysis of Single-Pull K East Basin Floor and Pit Sludges

International Nuclear Information System (INIS)

Bredt, P.R.; Delegard, C.H.; Schmidt, A.J.; Silvers, K.L.; Thornton, B.M.; Gano, S.

2000-01-01

This report presents the results of particle size analyses and calorimetry testing performed on selected single-pull sludge samples collected from the Hanford K East Basin between December 1998 and June 1999. The samples were collected as isolated cores predominantly from areas that had not been previously sampled (e.g., North Loadout Pit, Dummy Elevator Pit, Tech View Pit), or from areas in which the sludge composition had been altered since the last sampling (e.g., Weasel Pit). Particle size analyses were performed by washing wet sludge samples through a series of four sieves with openings of 250, 500, 1410, and 4000 microm. The loaded sieves were weighed before and after drying to obtain wet and dry particle size distributions. Knowledge of the particle size distribution is needed to design and predict the performance of the systems that will be used to retrieve, transport, and recover sludge. Also, sieving provides an opportunity to observe the components in the sludge. For example, during sieving of the sludge sample from the North Loadout Pit, significant quantities of organic ion exchange beads were observed. The uranium metal content and the particle size of the uranium metal in the K Basin sludge will largely determine the chemical reactivity of the sludge. In turn, the designs for the sludge handling and storage systems must be compatible with the reactivity of the sludge. Therefore, acid calorimetry was performed to estimate the uranium metal content of the sludge. For this testing, sludge samples were dissolved in nitric acid within a calibrated adiabatic calorimeter. The resulting dissolution enthalpy data were then used to discriminate between metallic uranium (minus3750 J/g in nitric acid) and uranium oxide (minus394 J/g in nitric acid). Results from this testing showed that the single-pull sludge samples contained little or no uranium metal

Control of corrosion in an aqueous nuclear fuel storage basin

International Nuclear Information System (INIS)

Zimmerman, C.A.

1981-01-01

Observations made during thirty years of experience in operating a nuclear fuel storage basin, used for storing a wide variety of spent nuclear fuels underwater have identified several forms of corrosion such as galvanic, pitting and crevice attack. Examples of some of the forms of corrosion observed and their causes are discussed, along with the measures taken to mitigate the corrosive attack. The paper also describes the procedure used to reduce corrosion by: surveillance of design, selection of materials for application in the basin, and inspection of items in the storage basin

Fish assemblages in borrow-pit lakes of the Lower Mississippi River

Science.gov (United States)

Miranda, Leandro E.; Killgore, K. J.; Hoover, J.J.

2013-01-01

Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in context with that of natural floodplain lakes. In all, we collected 75 fish species, including 65 species in eight borrow-pit lakes, 52 species in four riverside oxbow lakes, and 44 species in eight landside oxbow lakes. Significant differences in several species richness metrics were evident between borrow-pit lakes and landside oxbow lakes but not between borrow-pit lakes and riverside oxbow lakes. All three lake types differed in fish assemblage composition. Borrow-pit lakes and riverside oxbow lakes tended to include a greater representation of fish species that require access to diverse environments, including lentic, lotic, and palustrine habitats; fish assemblages in landside oxbow lakes included a higher representation of lacustrine species. None of the fish species collected in borrow-pit lakes was federally listed as threatened or endangered, but several were listed as species of special concern by state governments in the region, suggesting that borrow-pit lakes provide habitat for sensitive riverine and wetland fish species. Differences in fish assemblages among borrow-pit lakes were linked to engineered morphologic features, suggesting that diversity in engineering can contribute to diversity in fish assemblages; however, more research is needed to match engineering designs with fish assemblage structures that best meet conservation needs.

Modeling sludge accumulation rates in lined pit latrines in slum ...

African Journals Online (AJOL)

Yvonne

should include geo-physical characterization of soil and drainage of pit latrine sites so as ... Key words: Faecal, sludge accumulation rates, slum areas, lined pit latrines. .... Value and its unit Source .... overall quality of the models had to be assessed by validation on ..... Sanitation partnership series: Bringing pit emptying out.

Pitting and stress corrosion cracking of stainless steel

Science.gov (United States)

Saithala, Janardhan R.

An investigation has been performed to determine the pitting resistance of stainless steels and stress corrosion cracking of super duplex stainless steels in water containing chloride ions from 25 - 170°C. The steels studied are 12% Cr, FV520B, FV566, 304L, Uranus65, 2205, Ferallium Alloy 255, and Zeron 100. All these commercial materials used in very significant industrial applications and suffer from pitting and stress corrosion failures. The design of a new experimental setup using an autoclave enabled potentiodynamic polarisation experiments and slow strain rate tests in dilute environments to be conducted at elevated temperatures. The corrosion potentials were controlled using a three electrode cell with computer controlled potentiostat.The experimental programme to determine pitting potentials was designed to simulate the service conditions experienced in most industrial plants and develop mathematical model equations to help a design engineer in material selection decision. Stress corrosion resistance of recently developed Zeron100 was evaluated in dilute environments to propose a mechanism in chloride solutions at high' temperatures useful for the nuclear and power generation industry. Results have shown the significance of the composition of alloying elements across a wide range of stainless steels and its influence on pitting. Nitrogen and molybdenum added to modern duplex stainless steels was found to be unstable at higher temperatures. The fractographic results obtained using the scanning electron microscope (SEM) has given insight in the initiation of pitting in modem duplex and super duplex stainless steels. A mathematical model has been proposed to predict pitting in stainless steels based on the effect of environmental factors (temperature, chloride concentration, and chemical composition). An attempt has been made to identify the mechanism of SCC in Zeron100 super duplex stainless steel.The proposed empirical models have shown good correlation

Laboratory protocols for testing the efficacy of commercial pit latrine ...

African Journals Online (AJOL)

There is considerable national interest in the use of commercial microbially derived products for controlling the rate of accumulation of the contents of pit latrines. Manufacturers claim that some of these products can reduce accumulation rates, prevent the pit from ever filling up, or even result in decreases in pit contents ...

Long-term fate and transport of arsenic in an in-pit uranium mine tailings facility

International Nuclear Information System (INIS)

Moldovan, B.; Hendry, M.J.

2006-01-01

An important environmental issue facing the uranium mining industry in Saskatchewan is the quantification of the long-term migration of arsenic from its tailings facilities to the adjacent groundwater system. Decommissioning of these arsenic-rich tailings requires that the long-term arsenic source term for the tailings to the groundwater be defined. To meet this need, arsenic-rich uranium mine tailings from one in-pit tailings facility (tailings emplaced in a mined out open pit) were studied in detail. The tailings facility selected for study was the Rabbit Lake in-pit tailings management facility (RLITMF) in northern Saskatchewan, Canada. The tailings body in the RLITMF is 425 m long x 300 m wide x 100 m deep at its center and mill tailings were deposited in layers between 1985 (base) and 2004 (top). Associated with the low-level radioactive tailings is approximately 23,000 tonnes of arsenic. The in-pit design limits solute transport in these fine-grained tailings to diffusion. Because the layers of tailings have varying chemical characteristics (controlled by the ore being milled at the time), the total arsenic concentrations in the layers and their associated pore fluids range from 56 to 9,871 μ/g and 0.24 to 140 mg/l, respectively. As was the case for arsenic, the concentration of iron present in the layers was also variable (ranging from 8,967 to 30,247 μ/g). Synchrotron-based studies show that the arsenic in these tailings is strongly attenuated by adsorption to secondary 2-line ferrihydrite through inner sphere bidentate linkages. Single reservoir diffusion cell testing shows that the effective diffusion coefficient for arsenic in the tailings is 4.5 x 10 -10 m 2 s- 1 . Based on results from our field- and laboratory-based studies, the redistribution (via diffusion) and attenuation (via adsorption) of arsenic in the RLITMF was modelled using a one-dimensional geochemical reactive transport model to provide a source term for arsenic migration from the

105-KW Sandfilter Backwash Pit sludge volume calculation

International Nuclear Information System (INIS)

Dodd, E.N. Jr.

1995-01-01

The volume of sludge contained in the 100-KW Sandfilter Backwash Pit (SFBWP) was calculated from depth measurements of the sludge, pit dimension measurements and analysis of video tape recordings taken by an underwater camera. The term sludge as used in this report is any combination of sand, sediment, or corrosion products visible in the SFBWP area. This work was performed to determine baseline volume for use in determination of quantities of uranium and plutonium deposited in the pit from sandfilter backwashes. The SFBWP has three areas where sludge is deposited: (1) the main pit floor, (2) the transfer channel floor, and (3) the surfaces and structures in the SFBWP. The depths of sludge and the uniformity of deposition varies significantly between these three areas. As a result, each of the areas was evaluated separately. The total volume of sludge determined was 3.75 M 3 (132.2 ft 3 )

Management of Pit 9 - highlights of accomplishments and lessons learned to date

International Nuclear Information System (INIS)

Schwartz, F.G.

1995-01-01

The Pit 9 project is a U.S. Department of Energy prototype full scale demonstration to retrieve and treat buried mixed transuranic waste. The project is being managed by the DOE-Idaho Environmental Restoration Program, in conjunction with the Environmental Protection Agency Region 10 and the state of Idaho, under the Idaho National Engineering Laboratory Federal Facility Agreement and Consent Order. Pit 9 is located in the northeast corner of the Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering Laboratory (INEL). The Pit 9 project was conceived out of the need to determine capabilities to cost effectively retrieve and treat buried radioactive and radioactive mixed waste, and obtain characterization and contaminant migration data for buried waste at the INEL. Waste was disposed in Pit 9 from November 1967 to June 1969. Pit 9, at about 380 feet by 125 feet, represents approximately one acre of surface area of the 88 acre SDA. The pit contains approximately 350,000 ft 3 of soil beneath and between the buried waste and about 250,000 ft 3 of overburden soil. The average depth of the pit from soil surface to bedrock is approximately 17.5 feet. Approximately 110,000 ft 3 of transuranic (TRU) contaminated mixed wastes from Rocky Flats and approximately 40,000 ft 3 of low level and mixed wastes from the INEL were buried in Pit 9 during this period. Pit 9 is estimated to contain over 30,000 gallons of organics (over 30% of the total organic inventory in the SDA) and approximately 66 pounds of TRU radionuclides (between 3% and 4% of the total TRU inventory in the SDA). Pit 9 was selected as a demonstration site because it was one of the last disposal pits at the INEL to receive Rocky Flats waste, disposal records are better for Pit 9 than for disposal pits and trenches from earlier points in time, and the wastes in Pit 9 are representative of the wastes disposed in the SDA

Pit above the lesser tuberosity in axial view radiography.

Science.gov (United States)

Cho, Jae-Ho; Han, Kyeong-Jin; Lee, Doo-Hyung; Chung, Nam-Su; Park, Do Young

2015-02-01

This study examined the relationship between the presence of a pit above the lesser tuberosity on axial view radiographs and rotator cuff tears and compared the demographic data between groups according to the presence of a pit above the lesser tuberosity. The hypothesis of this study was that the radiographic finding of a pit above the lesser tuberosity is related to rotator cuff tears. For 112 patients with a symptomatic rotator cuff tear, plain radiographs of the symptomatic shoulder (tear side radiographs) and plain radiographs of the asymptomatic contralateral shoulder (no-tear side radiographs) were assessed. Seventeen radiological findings, including a pit above the lesser tuberosity, osteophytes, subchondral cysts, and sclerosis, were recorded by one blinded observer. Demographic data such as age, duration of symptoms, sex, arm dominance, smoking history, trauma history, American Shoulder and Elbow Surgeons score, Constant score, and involved tendon were collected. A pit above the lesser tuberosity was noted on tear side radiographs of 40 patients (35.7 %) and on the no-tear side radiographs of 27 patients (24.1 %), representing a significant difference (P = 0.040). A pit associated with a rotator cuff tear was observed more often in the dominant arm (P = 0.040) and more often in patients with less previous trauma (P = 0.024). A pit above the lesser tuberosity on axial view radiography was associated with a rotator cuff tear and occurred more often in the dominant arm of patients who had no trauma history. Prognostic study, Level III.

The phylogenetic significance of vestured pits in Boraginaceae

NARCIS (Netherlands)

Rabaey, D.; Lens, F.; Smets, E.; Jansen, S.

2010-01-01

The bordered pit structure in tracheary elements of 105 Boraginaceae species is studied using scanning electron microscopy to examine the systematic distribution of vestured pits. Forty-three species out of 16 genera show a uniform presence of this feature throughout their secondary xylem. Most

Structural evaluation of W-211 flexible receiver platforms and tank pit walls

International Nuclear Information System (INIS)

Shrivastava, H.P.

1997-01-01

This document is a structural analysis of the Flexible Receiver Platforms and the tank-pit wall during removal of equipment and during a accidental drop of that equipment. The platform and the pit walls must withstand a accidental drop of a mixer and transfer pumps in specific pits in tanks 102-AP and 104-AP. A mixer pump will be removed from riser 11 in pit 2A on tank 241-AP-102. A transfer pump will be removed from riser 13 in pit 2D on tank 241-AP-102 and another transfer pump will be removed from riser 3A in pit 4A on tank 241-AP-104

ON THE PROPAGATION OF OPEN AND COVERED PIT IN 316L STAINLESS STEEL

International Nuclear Information System (INIS)

Heurtault, Stéphane; Robin, Raphaël; Rouillard, Fabien; Vivier, Vincent

2016-01-01

Highlights: • The propagation of a single pit was investigated with a flow micro-device. • Both in depth and radial pit propagation were characterized. • The formation of a salt film in the pit was discussed. - Abstract: Pitting corrosion on stainless steel has been widely studied during the last decades, but since it is a stochastic process, it remains difficult to analyze experimentally such a phenomenon. In this work, reproducible single pits were performed on 316L steel by using an experimental setup based on the use of a glass microcapillary to locally supply chloride ions on the steel surface in order to characterize the pit propagation. This original approach allowed obtaining new results about pit propagation. Indeed, it was possible to control the presence of a metallic cap covering the pit by adjusting the experimental parameters (potential – chloride to sulfate ratio – temperature). The presence of this cover was shown to be an important issue concerning the propagation mechanism. It was also possible to study the evolution of both the pit depth and the pit diameter as a function of various parameters. Then, based on the simulation of the current densities at the pit bottom and at the pit aperture, a special attention has been paid for the investigation of the local propagation mechanism.

PITTING CORROSION OF STAINLESS STEEL AT THE VARIOUS SURFACE TREATMENT

Directory of Open Access Journals (Sweden)

Viera Zatkalíková

2011-09-01

Full Text Available The stainless steel surface treatment is very important with regard to its pitting corrosion susceptibility. An effect of various types surfacing on pitting corrosion resistance of AISI 304stainless steel is investigated in this work. The samples of the tested material are turned, blasted, peened, grinded and a half of them are pickled to achieve higher purity of surfaces and better quality of passive film. Eight types of different finished surfaces are tested by electrochemical and immersion tests to determine corrosion behaviour in conditions where pitting is evoked by controlled potential and second by solution with high redox potential. By this way the effect of mechanical and chemical surface treatment on the resistance to pitting corrosion, character, size and shape of pits are compared in the conditions of different mechanisms of corrosion process.

Effects of water deficit on breadmaking quality and storage protein compositions in bread wheat (Triticum aestivum L.).

Science.gov (United States)

Zhou, Jiaxing; Liu, Dongmiao; Deng, Xiong; Zhen, Shoumin; Wang, Zhimin; Yan, Yueming

2018-03-12

Water deficiency affects grain proteome dynamics and storage protein compositions, resulting in changes in gluten viscoelasticity. In this study, the effects of field water deficit on wheat breadmaking quality and grain storage proteins were investigated. Water deficiency produced a shorter grain-filling period, a decrease in grain number, grain weight and grain yield, a reduced starch granule size and increased protein content and glutenin macropolymer contents, resulting in superior dough properties and breadmaking quality. Reverse phase ultra-performance liquid chromatography analysis showed that the total gliadin and glutenin content and the accumulation of individual components were significantly increased by water deficiency. Two-dimensional gel electrophoresis detected 144 individual storage protein spots with significant accumulation changes in developing grains under water deficit. Comparative proteomic analysis revealed that water deficiency resulted in significant upregulation of 12 gliadins, 12 high-molecular-weight glutenin subunits and 46 low-molecular-weight glutenin subunits. Quantitative real-time polymerase chain reaction analysis revealed that the expression of storage protein biosynthesis-related transcription factors Dof and Spa was upregulated by water deficiency. The present results illustrated that water deficiency leads to increased accumulation of storage protein components and upregulated expression of Dof and Spa, resulting in an improvement in glutenin strength and breadmaking quality. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Congenital pits of the optic nerve head and retinochoroidal colobomas.

Science.gov (United States)

Brown, G C; Augsburger, J J

1980-07-01

A 45-year-old man presented with bilateral retinochoroidal colobomas associated with an inferonasal congenital pit of the optic nerve head in each eye. Different theories on the origin of such pits are discussed. This case supports the theory that some congenital optic pits occur as a result of failure of closure of the superior end of the embryonic fissure.

Effects of selected water chemistry variables on copper pitting propagation in potable water

International Nuclear Information System (INIS)

Ha Hung; Taxen, Claes; Williams, Keith; Scully, John

2011-01-01

Highlights: → The effects of water composition on pit propagation kinetics on Cu were separated from pit initiation and stabilization using the artificial pit method in a range of dilute HCO 3 - , SO 4 2- and Cl - -containing waters. → The effective polarization and Ohmic resistance of pits were lower in SO4 2- -containing solutions and greater in Cl - -containing solutions. → Relationship between the solution composition and the corrosion product identity and morphology were found. → These, in turn controlled the corrosion product Ohmic resistance and subsequently the pit growth rate. - Abstract: The pit propagation behavior of copper (UNS C11000) was investigated from an electrochemical perspective using the artificial pit method. Pit growth was studied systematically in a range of HCO 3 - , SO 4 2- and Cl - containing-waters at various concentrations. Pit propagation was mediated by the nature of the corrosion products formed both inside and over the pit mouth (i.e., cap). Certain water chemistry concentrations such as those high in sulfate were found to promote fast pitting that could be sustained over long times at a fixed applied potential but gradually stifled in all but the lowest concentration solutions. In contrast, Cl - containing waters without sulfate ions resulted in slower pit growth and eventual repassivation. These observations were interpreted through understanding of the identity, amount and porosity of corrosion products formed inside and over pits. These factors controlled their resistive nature as characterized using electrochemical impedance spectroscopy. A finite element model (FEM) was developed which included copper oxidation kinetics, transport by migration and diffusion, Cu(I) and Cu(II) solid corrosion product formation and porosity governed by equilibrium thermodynamics and a saturation index, as well as pit current and depth of penetration. The findings of the modeling were in good agreement with artificial pit experiments

Microstructural evolution and pitting resistance of annealed lean duplex stainless steel UNS S32304

International Nuclear Information System (INIS)

Zhang Ziying; Han Dong; Jiang Yiming; Shi Chong; Li Jin

2012-01-01

Highlights: ► The relationship between pitting corrosion resistance and annealing temperature for UNS S32304 was systemically studied. ► The specimens annealed at 1080 °C for 1 h, quenched in water exhibit the best pitting corrosion resistance. ► The relationship between microstructural evolution and pitting resistance of annealed UNS S32304 was discussed in detail. ► The pitting corrosion resistance is consistent with pitting resistance equivalent number of weaker phase for UNS S32304 alloy. - Abstract: The effect of annealing temperature in the range from 1000 to 1200 °C on the pitting corrosion behavior of duplex stainless steel UNS S32304 was investigated by the potentiodynamic polarization and potentiostatic critical pitting temperature techniques. The microstructural evolution and pit morphologies were studied using a scanning electron microscopy with energy dispersive X-ray spectroscopy. The results demonstrated that the nucleation of metastable pits transformed from austenite phase to ferrite phase with the increasing annealing temperature. As the annealing temperature increased, the pitting corrosion resistance firstly increased and then decreased. The highest pitting corrosion resistance was obtained at 1080 °C with the highest critical pitting temperature value and pitting nucleation resistance. The results could be well explained by the microstructural evolution of ferrite and austenite phases induced by annealing treatment.

Pitting growth rate in carbon steel exposed to simulated radioactive waste

International Nuclear Information System (INIS)

Zapp, P.E.

1995-01-01

Dilute high-level radioactive waste slurries can induce pitting corrosion in carbon steel tanks in which such waste is stored and processed. The waste is normally maintained with closely monitored nitrite and hydroxide concentrations known to prevent the initiation of pitting. Coupon immersion are being conducted in laboratory simulants of waste to determine the probability and growth rate of pitting in steel in the event of below-limits nitrite concentrations. Sets of about 36 carbon steel coupons have been immersed in known corrosive conditions (nitrite < 5% of the established limit) at a temperature of 50 C. Three sets have been removed from testing after 64, 150, and 350 days of immersion. The long immersion times introduced variability in the exposure conditions due to the evaporation and replenishment of solution. The deepest corrosive attack was measured one each coupon by optical microscopy. The deepest pits were ranked and analyzed as a type 1 extreme value distribution to extrapolate from the coupon population to the maximum pit depths in a waste tank structure. The data were compared to a power law for pit growth, although the deepest pits did not increase monotonically with time in the limited data set

Assessment and cleanup of the Taxi Strip waste storage area at LLNL [Lawrence Livermore National Laboratory

International Nuclear Information System (INIS)

Buerer, A.

1983-01-01

In September 1982 the Hazards Control Department of the Lawrence Livermore National Laboratory (LLNL) began a final radiological survey of a former low-level radioactive waste storage area called the Taxi Strip so that the area could be released for construction of an office building. Collection of soil samples at the location of a proposed sewer line led to the discovery of an old disposal pit containing soil contaminated with low-level radioactive waste and organic solvents. The Taxi Strip area was excavated leading to the discovery of three additional small pits. The clean-up of Pit No. 1 is considered to be complete for radioactive contamination. The results from the chlorinated solvent analysis of the borehole samples and the limited number of samples analyzed by gas chromatography/mass spectrometry indicate that solvent clean-up at this pit is complete. This is being verified by gas chromatography/mass spectrometry analysis of a few additional soil samples from the bottom sides and ends of the pit. As a precaution, samples are also being analyzed for metals to determine if further excavation is necessary. Clean-up of Pits No. 2 and No. 3 is considered to be complete for radioactive and solvent contamination. Results of analysis for metals will determine if excavation is complete. Excavation of Pit No. 4 which resulted from surface leakage of radioactive contamination from an evaporation tray is complete

Acidic pit lakes. The legacy of coal and metal surface mines

Energy Technology Data Exchange (ETDEWEB)

Geller, Walter; Schultze, Martin [Helmholtz Centre for Environmental Research - UFZ, Magdeburg (Germany); Wolkersdorfer, Christian (eds.) [Cape Breton Univ., Sydney, NS (Canada). Industrial Research Chair in Mine Water Remediation and Management; International Mine Water Association, Wendelstein (Germany). General Secretary; Kleinmann, Robert

2013-07-01

This monograph provides an international perspective on pit lakes in post-mining landscapes, including the problem of geogenic acidification. Much has been learned during the last decade through research and practical experience on how to mitigate or remediate the environmental problems of acidic pit lakes. In the first part of the book, general scientific issues are presented in 21 contributions from the fields of geo-environmental science, water chemistry, lake physics, lake modeling, and on the peculiar biological features that occur in the extreme habitats of acidic pit lakes. Another chapter provides an overview of methods currently used to remediate acidic pit lakes and treat outflowing acidic water. The second part of the book is a collection of regional surveys of pit lake problems from three European countries and Australia, and case studies of various individual representative lakes. A final case study provides an innovative approach to assessing the economic value of new pit lakes and balancing the costs and benefits, a valuable tool for decision makers.

Stochastic modeling of pitting corrosion in underground pipelines using Markov chains

Energy Technology Data Exchange (ETDEWEB)

Velazquez, J.C.; Caleyo, F.; Hallen, J.M.; Araujo, J.E. [Instituto Politecnico Nacional (IPN), Mexico D.F. (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE); Valor, A. [Universidad de La Habana, La Habana (Cuba)

2009-07-01

A non-homogenous, linear growth (pure birth) Markov process, with discrete states in continuous time, has been used to model external pitting corrosion in underground pipelines. The transition probability function for the pit depth is obtained from the analytical solution of the forward Kolmogorov equations for this process. The parameters of the transition probability function between depth states can be identified from the observed time evolution of the mean of the pit depth distribution. Monte Carlo simulations were used to predict the time evolution of the mean value of the pit depth distribution in soils with different physicochemical characteristics. The simulated distributions have been used to create an empirical Markov-chain-based stochastic model for predicting the evolution of pitting corrosion from the observed properties of the soil in contact with the pipeline. Real- life case studies, involving simulated and measured pit depth distributions are presented to illustrate the application of the proposed Markov chains model. (author)

Pitting corrosion of Inconel 600 in chloride and sulfate solutions at low temperature

International Nuclear Information System (INIS)

Chang Mingyu; Yu Geping

1993-01-01

Pitting corrosion of Inconel 600 was examined in chloride and sulfate solutions through usage of potentiodynamic polarization techniques. The effects of chloride and sulfate concentration were investigated in the range of 0.0001 to 0.1 M. Increasing chloride concentrations resulted in active shifts of the pit nucleation potential. Immunity to pitting corrosion was evident at a chloride level below 0.005 M. Increasing sulfate concentrations resulted in improved pitting resistance of Inconel 600 in chloride solutions. Detrimental effects associated with pitting were evident with low-level sulfate being added to dilute chloride media. The density of pits increased with increasing chloride concentrations or temperature between room temperature and 70 C. Systematic trends for the depth of pits were not evident. The observations of pitting corrosion in open immersion were consistent with those in polarization methods. Corrosion products contained in the pits were enriched in nickel, chromium and iron with a small amount of titanium and silicon. The enrichment of chlorine or sulfur was still, however, not found. (orig.)

A numerical study of under-deposit pitting corrosion in sour petroleum pipelines

Energy Technology Data Exchange (ETDEWEB)

Zhu, Z.; Sand, K.W.; Teevens, P.J. [Broadsword Corrosion Engineering Ltd., Calgary, AB (Canada)

2010-07-01

Insufficient fluid velocity in petroleum pipelines can lead to the deposit of sand, corrosion products, and non-corrosion products on the pipe's metal surface, which in turn can lead to pitting corrosion. There is currently no reliable means of detecting and preventing the pitting process. This paper presented a computerized simulation tool that used the finite element method to model mass transfer-governed internal pitting corrosion under solids deposition in sour petroleum pipelines. The computational domain consisted of a hemispherical pit and a thin stagnant solution film under a surface deposit. The moving mesh method was used to track pitting growth. A Poisson equation was used to determine aqueous path migration of ions. Pitting corrosion rates were estimated using the Nernst-Planck equation. The model was used to predict the effects of different operating parameters on pitting corrosion rates. The model can be used to develop pigging and in-line-inspection (ILI) procedures. 35 refs., 2 tabs., 16 figs.

Changes in fungi and mycotoxins in pearl millet under controlled storage conditions.

Science.gov (United States)

Jurjevic, Zeljko; Wilson, Jeffrey P; Wilson, David M; Casper, Howard H

2007-11-01

Pearl millet is increasingly being grown as a premium-value grain for the recreational wildlife and poultry industries in the southern US. We conducted three experiments to assess grain mold development in storage conditions typically encountered in the region of production. Variables included production year, temperature, relative humidity, atmosphere, and grain moisture content. In the first experiment, grain was stored for 9 weeks at 20 or 25 degrees C and maintained at 86% or 91% relative humidity (r.h.). In the second experiment, grain was stored for 9 weeks at 20 or 25 degrees C in either air (aerobic) or N2 (anaerobic), and maintained at 100% r.h. In the third experiment, high-moisture grain was stored for 3 weeks at 20 or 25 degrees C and maintained at 100% r.h. Grain was sampled at weekly intervals and plated to determine changes in fungal frequency. Fungi isolated included Fusarium chlamydosporum (19% of grain), Curvularia spp. (14%), F. semitectum (16%), Alternaria spp. (9%), Aspergillus flavus (8%), "Helminthosporium"-type spp. (6%), and F. moniliforme sensu lato (3%). Year of grain production significantly affected isolation frequency of fungi. Isolation frequencies from low-moisture grain were rarely affected by temperature, relative humidity, or atmosphere treatments, but was affected by storage duration for some fungi. Changes in isolation of toxigenic fungi occurred in high-moisture grain. Isolation frequency of F. chlamydosporum increased in grain stored at 86% and 91% r.h. Incidence of A. flavus increased in high-moisture grain treatments, particularly at 25 degrees C. Incidence of deoxynivalenol was not affected by storage treatment. Low concentrations of nivalenol were detected in most grain incubated at 100% r.h. Zearalenone was detected only when grain moisture content was 20-22%. Aflatoxin contamination averaged 174 ng g(-1) over all treatments, and increased up to 798 ng g(-1) in high-moisture grain at stored at 25 degrees C.

Clinico epidemiological study of pitted keratolysis

Directory of Open Access Journals (Sweden)

Naik Chandra

2007-01-01

Full Text Available Background: Pitted keratolysis is a common dermatological condition. However, very few studies are available on the clinical characteristics and epidemiological features of this disorder from India and abroad. Materials and Methods: Fifty patients from rural area of Kolar at Sri R.L.J.H. and S.N.R. Hospital, presenting with clinically distinctive lesions of pitted keratolysis were included in the study. Cases were interviewed with particular emphasis on triggering factors and findings were recorded. Investigations like Gram′s stain, culture studies, Wood′s ultraviolet light examination, histopathology etc, was done in selected cases to ascertain the clinical diagnosis. Results: Age of the patients varied from 20 to 40 years in 52% with male preponderance in 82% of cases. Duration of the disease varied from 15 days to five years, most of the patients were bare-footed farmers (62% of cases. Hyperhidrosis and pruritus were most frequently observed symptoms in 70% and 60% of patients. Most of the patients presented with the characteristic pits which varied from 1 to 50 in number in 56 % of cases, located predominantly on the pressure bearing areas in 92% of cases and depth of the pits varied from 1 to 2 mm in 60% of cases. Associated skin conditions recorded in present study were fissuring of soles in 38%, psoriasis 10%, dermatophyte infections in 6%, planter warts 6% and Corynebacterial triad and corn in 2% of patients each. Discussion: Affection of bare-footed individuals, male preponderance, presence of hyperhidrosis and occurrence of lesions over pressure bearing areas of soles, observed in the present study were consistent with earlier studies on the subject. However, pruritus as commonest presenting symptom reported by 60% patients in the present study, has not been documented in the previous studies. Conclusion: Pitted keratolysis is fairly common in bare footed male farmers of rural India. The condition is predominantly seen over the

Corrosion pit depth extreme value prediction from limited inspection data

International Nuclear Information System (INIS)

Najjar, D.; Bigerelle, M.; Iost, A.; Bourdeau, L.; Guillou, D.

2004-01-01

Passive alloys like stainless steels are prone to localized corrosion in chlorides containing environments. The greater the depth of the localized corrosion phenomenon, the more dramatic the related damage that can lead to a structure weakening by fast perforation. In practical situations, because measurements are time consuming and expensive, the challenge is usually to predict the maximum pit depth that could be found in a large scale installation from the processing of a limited inspection data. As far as the parent distribution of pit depths is assumed to be of exponential type, the most successful method was found in the application of the statistical extreme-value analysis developed by Gumbel. This study aims to present a new and alternative methodology to the Gumbel approach with a view towards accurately estimating the maximum pit depth observed on a ferritic stainless steel AISI 409 subjected to an accelerated corrosion test (ECC1) used in automotive industry. This methodology consists in characterising and modelling both the morphology of pits and the statistical distribution of their depths from a limited inspection dataset. The heart of the data processing is based on the combination of two recent statistical methods that avoid making any choice about the type of the theoretical underlying parent distribution of pit depths: the Generalized Lambda Distribution (GLD) is used to model the distribution of pit depths and the Bootstrap technique to determine a confidence interval on the maximum pit depth. (authors)

Template measurement for plutonium pit based on neural networks

International Nuclear Information System (INIS)

Zhang Changfan; Gong Jian; Liu Suping; Hu Guangchun; Xiang Yongchun

2012-01-01

Template measurement for plutonium pit extracts characteristic data from-ray spectrum and the neutron counts emitted by plutonium. The characteristic data of the suspicious object are compared with data of the declared plutonium pit to verify if they are of the same type. In this paper, neural networks are enhanced as the comparison algorithm for template measurement of plutonium pit. Two kinds of neural networks are created, i.e. the BP and LVQ neural networks. They are applied in different aspects for the template measurement and identification. BP neural network is used for classification for different types of plutonium pits, which is often used for management of nuclear materials. LVQ neural network is used for comparison of inspected objects to the declared one, which is usually applied in the field of nuclear disarmament and verification. (authors)

Cormorant predation on PIT-tagged lake fish

DEFF Research Database (Denmark)

Skov, Christian; Jepsen, Niels; Baktoft, Henrik

2014-01-01

The present study use data from recovered PIT (Passive Integrated Transponder) tags to explore species-and size-specific annual predation rates by cormorants on three common lacustrine fishes (size range 120-367 mm) in a European lake; roach (Rutilus rutilus), common bream (Abramis brama) and perch...... (Perca fluviatilis). In addition, we quantify the level of age/size truncation that cormorant predation could introduce in a population of perch, an important fish for recreational angling as well as for trophic interactions and ecosystem function in European lakes. Based on three years of PIT tagging...... of fish in Lake Viborg and subsequent recoveries of PIT tags from nearby cormorant roosting and breeding sites, we show that cormorants are major predators of roach, bream and perch within the size groups we investigated and for all species larger individuals had higher predation rates. Perch appear...

Solar Thermal Power Generation 2000: solar-assisted district heating, tight sealing of pit water storage tanks made out of pre-stressed concrete; Solarthermie 2000, TP3: Solarunterstuetzte Nahwaermeversorgung: Dichte Heisswasser - Waermespeicher aus Hochleistungsbeton. Erdbeckenspeicher aus Hochleistungsbeton

Energy Technology Data Exchange (ETDEWEB)

Reineck, K.H.; Lichtenfels, A.; Schlaich, J. [Stuttgart Univ. (Germany). Inst. fuer Konstruktion und Entwurf 2

1998-12-31

In 1996 the two large heat storage tanks in Hamburg-Bramfeld (4,750 cubic metres) and Friedrichshafen-Wiggenhausen (12,000 cubic metres) were built out of concrete with an inner stainless steel lining. This was a big step towards economic efficiency. The research project ``Tight sealing of pit water storage tanks made out of pre-stressed concrete`` was launched by the BMBF in order to show that the concrete construction will not only bear loads but also ensure sealing. Building costs for underground hot water storage tanks could then be reduced by at least 25%. The first results of this research project are presented. The paper also contains recommendations for the further development of heat storage tanks built with pre-stressed concrete. (orig.) [Deutsch] Im Jahre 1996 wurden die beiden grossen Waermespeicher in Hamburg-Bramfeld mit einem Volumen von 4.750 m{sup 3} und in Friedrichshafen-Wiggenhausen mit 12.000 m{sup 3} aus Beton mit innenliegender Edelstahlauskleidung fertiggestellt. Mit dem Bau dieser beiden Grossspeicher konnte ein richtungsweisender Schritt hin zur Wirtschaftlichkeit gemacht werden, wie man es in Studien vor 15 Jahren nicht fuer moeglich hielt. Mit dem BMBF - Forschungsvorhaben `Dichte Heisswasser - Waermespeicher aus Hochleistungsbeton` soll gezeigt werden, dass das Betontragwerk nicht nur Lasten abtragen sondern auch die Funktion der Abdichtung uebernehmen kann. Damit sollen die Baukosten fuer unterirdische Heisswasser-Waermespeicher um mindestens 25% gesenkt werden. Es werden die ersten Ergebnisse dieses Forschungsvorhabens mitgeteilt und Empfehlungen fuer die weitere Entwicklung von Waermespeichern aus Hochleistungsbeton gegeben. (orig.)

The kinetics of pitting corrosion of carbon steel

International Nuclear Information System (INIS)

Marsh, G.P.; Taylor, K.J.; Sooi, Z.

1988-02-01

The development of an improved statistical method for analysing pit growth data to take account of the difference in area of laboratory specimens and full sized high level nuclear waste containers is described. Statistical analysis of data from pit growth experiments with large area (460 cm 2 ) plates of BS 4360 steel have indicated that the depth distributions correlate most closely with a limited distribution function. This correlation implies that previous statistical analyses to estimate the maximum pit depths in full size containers, which were made using unlimited distribution functions, will be pessimistic. An evaluation of the maximum feasible pitting period based on estimating the period during which the oxygen diffusion flux is sufficient to stabilise a passive film on carbon steel containers has indicated that this is of the order of 125 years rather than the full 1000 year container life. The estimate is sensitive to the value of the leakage current assumed to flow through the passive film, and therefore work is planned to measure this accurately in relevant granitic environments. (author)

Corrosion assessment of dry fuel storage containers

Energy Technology Data Exchange (ETDEWEB)

Graves, C.E.

1994-09-01

The structural stability as a function of expected corrosion degradation of 75 dry fuel storage containers located in the 200 Area Low-Level Waste Burial Grounds was evaluated. These containers include 22 concrete burial containers, 13 55-gal (208-l) drums, and 40 Experimental Breeder Reactor II (EBR-II) transport/storage casks. All containers are buried beneath at least 48 in. of soil and a heavy plastic tarp with the exception of 35 of the EBR-II casks which are exposed to atmosphere. A literature review revealed that little general corrosion is expected and pitting corrosion of the carbon steel used as the exterior shell for all containers (with the exception of the concrete containers) will occur at a maximum rate of 3.5 mil/yr. Penetration from pitting of the exterior shell of the 208-l drums and EBR-II casks is calculated to occur after 18 and 71 years of burial, respectively. The internal construction beneath the shell would be expected to preclude containment breach, however, for the drums and casks. The estimates for structural failure of the external shells, large-scale shell deterioration due to corrosion, are considerably longer, 39 and 150 years respectively for the drums and casks. The concrete burial containers are expected to withstand a service life of 50 years.

Pitting growth rate in carbon steel exposed to simulated radioactive waste

International Nuclear Information System (INIS)

Zapp, P.E.

1996-06-01

Dilute high-level radioactive waste slurries can induce pitting corrosion in carbon steel tanks in which such waste is stored and processed. The waste is normally maintained with closely monitored nitrite and hydroxide concentrations known to prevent the initiation of pitting. Coupon immersion tests are being conducted in laboratory simulants of waste to determine the probability and growth rate of pitting in steel in the event of out-of-limits nitrite concentrations. Sets of about 36 carbon steel coupons have been immersed in known corrosive conditions (nitrite < 5 per cent of the established limit) at a temperature of 50 degrees C. Three sets have been removed from testing after 64, 150, and 350 days of immersion. The long immersion times introduced variability in the exposure conditions due to the evaporation and replenishment of solution. The deepest corrosive attack was measured on each coupon by optical microscopy. The deepest pits were ranked and analyzed as a type 1 extreme value distribution to extrapolate from the coupon population to the maximum expected pit depths in a waste tank structure. The data were compared to a power law for pit growth, although the deepest pits did not increase monotonically with time in the limited data set

FY17 Status Report: Research on Stress Corrosion Cracking of SNF Interim Storage Canisters.

Energy Technology Data Exchange (ETDEWEB)

Schindelholz, Eric John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Alexander, Christopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

This progress report describes work done in FY17 at Sandia National Laboratories (SNL) to assess the localized corrosion performance of container/cask materials used in the interim storage of spent nuclear fuel (SNF). Of particular concern is stress corrosion cracking (SCC), by which a through-wall crack could potentially form in a canister outer wall over time intervals that are shorter than possible dry storage times. Work in FY17 refined our understanding of the chemical and physical environment on canister surfaces, and evaluated the relationship between chemical and physical environment and the form and extent of corrosion that occurs. The SNL corrosion work focused predominantly on pitting corrosion, a necessary precursor for SCC, and process of pit-to-crack transition; it has been carried out in collaboration with university partners. SNL is collaborating with several university partners to investigate SCC crack growth experimentally, providing guidance for design and interpretation of experiments.

Remaining Sites Verification Package for the 100-F-44:4, Discovery Pipeline in Silica Gel Pit. Attachment to Waste Site Reclassification Form 2008-030

International Nuclear Information System (INIS)

Capron, J.M.

2008-01-01

The 100-F-44:4, Discovery Pipeline in Silica Gel Pit subsite is located in the 100-FR-1 Operable Unit of the Hanford Site, near the location of the former 110-F Gas Storage Tanks structure. The 100-F-44:4 subsite is a steel pipe discovered October 17, 2004, during trenching to locate the 118-F-4 Silica Gel Pit. Based on visual inspection and confirmatory investigation sampling data, the 100-F-44:4 subsite is a piece of non-hazardous electrical conduit debris. The 100-F-44:4 subsite supports unrestricted future use of shallow zone soil and is protective of groundwater and the Columbia River. No residual contamination exists within the deep zone. Therefore, no deep zone institutional controls are required

Pitting Corrosion of Ni3(Si,Ti Intermetallic Compound at Various Chloride Concentrations

Directory of Open Access Journals (Sweden)

Gadang Priyotomo

2013-10-01

Full Text Available The pitting corrosion of Ni3(Si,Ti intermetallic compound was investigated as function of chloride concentration by using electrochemical method and scanning electron microscope in sodium chloride solutions at 293 K.  In addition, the pitting corrosion of type C276 alloy was also studied under the same experimental condition for comparison.  The pitting potential obtained for the intermetallic compound decreased with increasing chloride concentration.  The specific pitting potential and pitting potential of Ni3(Si,Ti were lower than those of C276 alloy, which means that the pitting corrosion resistance of C276 alloy was higher than that of Ni3(Si,Ti.

Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches

Science.gov (United States)

Smith, Stephen W.; Newman, John A.; Piascik, Robert S.

2003-01-01

Uniaxial fatigue tests were conducted to compare the fatigue life of laboratory produced corrosion pits, similar to those observed in the shuttle main landing gear wheel bolt-hole, and an electro-discharged-machined (EDM) flaw. EDM Jaws are used to simulate corrosion pits during shuttle wheel (dynamometer) testing. The aluminum alloy, (AA 7050) laboratory fatigue tests were conducted to simulate the local stress level contained in the wheel bolt-hole. Under this high local stress condition, the EDM notch produced a fatigue life similar to test specimens containing corrosion pits of similar size. Based on the laboratory fatigue test results, the EDM Jaw (semi-circular disc shaped) produces a local stress state similar to corrosion pits and can be used to simulate a corrosion pit during the shuttle wheel dynamometer tests.

Non Destructive Testing Measurement for Monitoring Pitting Corrosion using Dcp Techniques

International Nuclear Information System (INIS)

Atlam, A.; Omar, A.A.; Habashy, M.; Waheed, A.F.; Shafy, M.

2010-01-01

A repeatable monitoring of pit from in accessible side of a welded side of a structure is one of the hurdles in field of NT. The present work uses the DC potential drop measuring system for evaluating the response of pits in the weld joins to be detected by DC potential drop measurements. Weld joint of type 304L stainless steel welded with 308L was tested. Selected pits in different zones of the weld joint were detected by optical microscopy. The PD test shows difference in potential between pitted and non-pitted weld joints ranging from 1.3 in BM to 1.7 in HAZ. The capability of present monitoring process can be extended to evaluate the reduction in thickness for the case of thick stainless steel structure

Study of pitting corrosion in line-pipe steel under the influence of remanent magnetization

Energy Technology Data Exchange (ETDEWEB)

Espina-Hernandez, J H; Caleyo, F; Hallen, J M [Instituto Politecnico Nacional (IPN), Zacatenco (Mexico)

2009-07-01

The influence of remanent magnetization on pitting corrosion in line-pipe steels is studied. Pitting corrosion experiments have been carried out on samples of an API 5L grade 52 steel under a magnetization level of the same order of magnitude of the remanent magnetization in the pipeline wall after in-line inspection based on magnetic flux leakage. The samples were magnetized using rings of the same grade as the investigated steel. Immediately after magnetization, the investigated samples were subjected to pitting by immersing them in a solution containing dissolved Cl{sup -} and SO{sup 2-}{sub 4} and ions. The pitting experiments were conducted during a seven days period. The pit depth distribution and the maximum pit depth in each sample were recorded and used to conduct extreme value analyses of the pitting process in magnetized and non-magnetized control samples. The statistical assessment of the pitting corrosion data collected during this study shows that the magnetic field reduces the average depth of the pit population and also the extreme pit depth values that can be predicted from the maximum values observed in the magnetized samples in comparison with to the non-magnetized control samples. Scanning electron microscopy observations show that the magnetic field alters the pit morphology by increasing the pit mouth opening. (author)

The influence of α-amylase supplementation, γ-irradiation (60Co) as well as long time of storage of wheat grain on flour technological properties

International Nuclear Information System (INIS)

Warchalewski, J.R.

1989-01-01

The varieties of winter wheat, Aria and Beta, were studied. The Aria variety was stored for the period of four years. The part of wheat grain from Beta variety was irradiated with γ rays ( 60 Co). In extracts from wheat kernels and flour protein content, total α- and β-amylolytic activity as well as α-amylolytic activity were determined, α-amylases of native and fungal origin were added to the flour obtained from samples of stored wheat kernels (Aria), irradiated and non-irradiated (Beta). Consequently native α-amylase activity of flour increased by 25% and 50%, respectively. Extensive technological estimation of grain and flour with amylase supplements was carried out. The study included: sedimentation analysis, falling number test, milling experiment, farinogram and extensogram analyses, measurement of the degree of damaged starch and flour colour, as well as baking experiment. The obtained experimental loaves of bread were tested for their ability to remain fresh. It was found out that the stored grain flour was characterized by the highest α-amylolytic activity and the lowest falling number value, whereas the irradiated grain flour showed the highest degree of starch damage and water absorption. When α-amylase supplementation to doughs was not accompanied by either irradiation or storage of grain, it definitely changed their physical properties for the worse. The negative influence of native α-amylases appeared to be less significant than that of fungal α-amylases. The positive influence of α-amylase supplementations, especially of those increasing by 25% the native α-amylolytic activity of flour on volume, and freshness of loaves of bread was observed. (author)

New developments in dry spent fuel storage

International Nuclear Information System (INIS)

Bonnet, C.; Chevalier, Ph.

2001-01-01

As shown in various new examples, HABOG facility (Netherlands), CERNAVODA (Candu - Romania), KOZLODUY (WWER - Bulgaria), CHERNOBYL ( RMBK - Ukraine), MAYAK (Spent Fuel from submarine and Icebreakers - Russia), recent studies allow to confirm the flexibility and performances of the CASCAD system proposed by SGN, both in safety and operability, for the dry storage of main kinds of spent fuel. The main features are: A multiple containment barrier system: as required by international regulation, 2 independent barriers are provided (tight canister and storage pit); Passive cooling, while the Fuel Assemblies are stored in an inert atmosphere and under conditions of temperature preventing from degradation of rod cladding; Sub-criticality controlled by adequate arrangements in any conditions; Safe facility meeting ICPR 60 Requirements as well as all applicable regulations (including severe weather conditions and earthquake); Safe handling operations; Retrievability of the spent fuel either during storage period or at the end of planned storage period (100 years); Future Decommissioning of the facility facilitated through design optimisation; Construction and operating cost-effectiveness. (author)

Markov Chain Models for the Stochastic Modeling of Pitting Corrosion

OpenAIRE

Valor, A.; Caleyo, F.; Alfonso, L.; Velázquez, J. C.; Hallen, J. M.

2013-01-01

The stochastic nature of pitting corrosion of metallic structures has been widely recognized. It is assumed that this kind of deterioration retains no memory of the past, so only the current state of the damage influences its future development. This characteristic allows pitting corrosion to be categorized as a Markov process. In this paper, two different models of pitting corrosion, developed using Markov chains, are presented. Firstly, a continuous-time, nonhomogeneous linear growth (pure ...

Resistance to pitting corrosion in ferritic and austenitic/ferritic steels

International Nuclear Information System (INIS)

De Bouvier, O.

1995-01-01

Stainless steel tubes carrying raw water are potentially vulnerable to pitting corrosion. With a view to minimizing the corrosion risk in the river-water-cooled condensers at PWR power plant, a study was conducted to determine initiation conditions and incubation durations for pitting corrosion in stagnant water. As a result, condenser tubes in Z2 CI 18 (439) or Z2 CT 18-10 (304L) steels were phased out in favour of Z2 CND 16-32 (316L) stainless steel. The same question can be yield for other applications and especially for all types of exchangers for use in electrical applications. This study sought to assess alternative methods for estimating pitting corrosion, and to check the results of these methods against the actual behaviour of studied steels. The study covered ferritic steels (439, 444, 290Mo), austenitic steel (316L) and austenitic/ferritic steels (Uranus 35N, 45N, 47N, 52N). Two approaches were adopted: laboratory tests to compare pitting corrosion risks on different materials, and tests for characterizing the behaviour of steels exposed to river water. The study begins with a laboratory tests that yield an arbitrary parameter for quantifying pitting corrosion resistance. One method involves measuring the pitting temperature in an aggressive ferric chloride solution. Other methods measure the pitting potential, either statistically (Multipit method) or deterministically (polarization curve). We then go on to discuss tests under simulated life-like conditions, involving repeated immersions in water from the Seine. (author). 9 refs., 13 figs, 9 tabs

Gas cylinder disposal pit remediation waste minimization and management

International Nuclear Information System (INIS)

Alas, C.A.; Solow, A.; Criswell, C.W.; Spengler, D.; Brannon, R.; Schwender, J.M.; Eckman, C.K.; Rusthoven, T.

1995-01-01

A remediation of a gas cylinder disposal pit at Sandia National Laboratories, New Mexico has recently been completed. The cleanup prevented possible spontaneous releases of hazardous gases from corroded cylinders that may have affected nearby active test areas at Sandia's Technical Area III. Special waste management, safety, and quality plans were developed and strictly implemented for this project. The project was conceived from a waste management perspective, and waste minimization and management were built into the planning and implementation phases. The site layout was planned to accommodate light and heavy equipment, storage of large quantities of suspect soil, and special areas to stage and treat gases and reactive chemicals removed from the pit, as well as radiation protection areas. Excavation was a tightly controlled activity using experienced gas cylinder and reactive chemical specialists. Hazardous operations were conducted at night under lights, to allow nearby daytime operations to function unhindered. The quality assurance plan provided specific control of, and documentation for, critical decisions, as well as the record of daily operations. Both hand and heavy equipment excavation techniques were utilized. Hand excavation techniques were utilized. Hand excavation techniques allows sealed glass containers to be exhumed unharmed. In the end, several dozen thermal batteries; 5 pounds (2.3 kg) of lithium metal; 6.6 pounds (3.0 kg) of rubidium metal; several kilograms of unknown chemicals; 140 cubic yards (107 cubic meters) of thorium-contaminated soil; 270 cubic yards (205 cubic meters) of chromium-contaminated soil; and 450 gas cylinders, including 97 intact cylinders containing inert, flammable, toxic, corrosive, or oxidizing gases were removed and effectively managed to minimize waste

Lysine metabolism in antisense C-hordein barley grains

DEFF Research Database (Denmark)

Schmidt, Daiana; Rizzi, Vanessa; Gaziola, Salete A

2015-01-01

The grain proteins of barley are deficient in lysine and threonine due to their low concentrations in the major storage protein class, the hordeins, especially in the C-hordein subgroup. Previously produced antisense C-hordein transgenic barley lines have an improved amino acid composition, with ...

5G in Open-Pit Mines

DEFF Research Database (Denmark)

Portela Lopes de Almeida, Erika; Caldwell, George; Rodriguez Larrad, Ignacio

2017-01-01

5G will play a pivotal role in the digitization of the industrial sector and is expected to make the best use of every bit of spectrum available. In this light, this paper presents the results of an extensive measurement campaign in two iron-ore open-pit mining complexes, at the 700 MHz and 2.6 GHz...... for the future wireless network design, simulation and performance evaluation. The results show that, in order to comply with ultra-reliable communications (URC) availability requirements, larger shadowing margins will have to be considered in the network planning in open-pit mines, when compared to traditional...

Experimental research on friction coefficient between grain bulk and bamboo clappers

Science.gov (United States)

Tang, Gan; Sun, Ping; Zhao, Yanqi; Yin, Lingfeng; Zhuang, Hong

2017-12-01

A silo is an important piece of storage equipment, especially in the grain industry. The internal friction angle and the friction coefficient between the grain and the silo wall are the main parameters needed for calculating the lateral pressure of the silo wall. Bamboo is used in silo walls, but there are no provisions about the friction coefficient between bulk grain and bamboo clappers in existing codes. In this paper, the material of the silo wall is bamboo. The internal friction of five types of grain and the friction coefficient between the grain and the bamboo clappers were measured with an equal-strain direct shear apparatus. By comparing the experimental result values with the code values, the friction coefficient between the grain bulk and bamboo clappers is lower than that between grain and steel wall and that between grain and concrete wall. The differences in value are 0.21 and 0.09, respectively.

Influence of lubricant on the pitting capacity of gears. Comparison and discussion of main pitting test methods

Energy Technology Data Exchange (ETDEWEB)

Hoehn, Bernd-Robert; Oster, Peter; Tobie, Thomas; Hergesell, Maria [Forschungsstelle fuer Zahnraeder und Getriebebau, Technische Univ. Muenchen, Garching (Germany)

2009-07-01

The lubricant in a gearbox should provide a separating lubricating film between the meshing teeth. Furthermore its main task is the evacuation of the developing heat. Hence the lubricant is also an important influence parameter on the pitting life time of gearsets. Due to the constantly rising demands for higher power transmission of gearsets, also higher demands are made against the performance of the lubricants. In order to quantify the capability and to choose the appropriate lubricant for each application, reliable testing methods are necessary. Therefor today different testing methods are available. Two of the main pitting testing methods are the Standard Pittingtest according to FVA 2/IV [2] and its advancement, the Practice Relevant Pittingtest according to FVA 371 [4]. For the Practice Relevant Pittingtest test gears with profile modification and lengthwise crowning are used, which are superfinished. For the introduction of the Practice Relevant Pittingtest into industrial application a round robin test was performed in co-operation with FVA and DGMK. This paper is discussing the today usual testing methods regarding the pitting load capacity of lubricants and their characteristics in comparison. Furthermore the results of the round robin test and further example results, including pictures of typical pittings, are presented. In addition it is demonstrated, how to deal with the results. On the basis of test experience, knowledge from research projects and other examples typical questions concerning the different testing methods are discussed. Thereby essential requirements for reliable and reproducible results are pointed out and possible limits for the application of the test methods are represented. (orig.)

In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

International Nuclear Information System (INIS)

Spalding, B.P.; Bogle, M.A.; Cline, S.R.; Naney, M.T.; Gu, B.

1997-12-01

A treatability study was initiated in October 1993, initially encompassing the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was to have supported a possible Interim Record of Decision (IROD) or removal action for closure of one or more of the seepage pits and trenches as early as FY 1997. The Remedial Investigation/Feasibility Study for Waste Area Grouping (WAG) 7, which contains these seven seepage pits and trenches, will probably not begin until after the year 2000. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability to overlap melt settings that are necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 137 Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. This report summarizes the site characterization information gathered through the end of September 1996 which supports the planning and assessment of ISV for Pit 1 (objective 4 above)

In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

Energy Technology Data Exchange (ETDEWEB)

Spalding, B.P.; Bogle, M.A.; Cline, S.R.; Naney, M.T.; Gu, B.

1997-12-01

A treatability study was initiated in October 1993, initially encompassing the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was to have supported a possible Interim Record of Decision (IROD) or removal action for closure of one or more of the seepage pits and trenches as early as FY 1997. The Remedial Investigation/Feasibility Study for Waste Area Grouping (WAG) 7, which contains these seven seepage pits and trenches, will probably not begin until after the year 2000. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability to overlap melt settings that are necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of {sup 137}Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. This report summarizes the site characterization information gathered through the end of September 1996 which supports the planning and assessment of ISV for Pit 1 (objective 4 above).

Pitting process visualization

Directory of Open Access Journals (Sweden)

Michal Černý

2010-01-01

Full Text Available The paper describes time-domain simulation of gear pitting damage using animation program. Key frames have been used to create illusion of motion. The animation uses experimental results of high-cycle fatigue of material. The fatigue damage occurs in the nominal creep area on the side of the gear tooth sample loaded with variable-positioned Hertz pressure. By applying the force, the pressure cumulates between two convex surfaces. This phenomenon results in material damage under of curved surfaces in contact. Moreover, further damage has been registered on the surface. This is due to exceeding the elastic-plastic state limit and development of „tabs“. The tabs serve as origin of surface micro cracks powered by shear stress and enclosed grease pressure as well. This deformation and extreme pressures of Pascal law contribute to elongation and growth of the surface micro crack. Non-homogenous parts of material volume support the initialization/development of the micro cracks as well. Resulting visualization of the tooth-side fatigue damage provides clear and easy-to-understand description of the damage development process right from the micro crack initialization to the final fragmentation due to pitting degradation.

Pitting by corrosion in aluminium and Al-6201 alloy

International Nuclear Information System (INIS)

Vera, R.; Schrebler, R.; Layana, G.; Orellana, F.; Olguin, A.

1998-01-01

The susceptibility of pure aluminum 6201 alloy to pitting was investigated in sodium chloride solutions through determination of the corrosion, repassivation and pitting potentials. Potentiodynamic polarization including scratching techniques were employed being also determined the type and relative amount of corrosion damage to the metals. The morphology of the attach was determined using scanning electrons microscopy (SEM). The results showed a similar performance for aluminum 6201 alloy and aluminum. It was also observed that an increase in chloride concentration resulted in a decrease in the corrosion, pitting and repassivation potentials of both materials. (Author) 19 refs

Pitting of Incoloy 800 in presence of CuII

International Nuclear Information System (INIS)

Bianchi, G.L.; Alvarez, M.G.

1993-01-01

The pitting behaviour of Incoloy 800 in presence of Cu II ions, at 60 degrees C and 280 degrees C was studied by long term exposition of specimens in aqueous cupric chloride solutions. At 60 degrees C experiments were performed in aerated (7 ppm O 2 ) and deaerated solutions containing 500, 1000, 2000, 10000 and 20000 ppm CuCl 2 . At 280 degrees C experiments were performed in deaerated 20 ppm, 50 ppm and 100 ppm CuCl 2 solutions. During each experiment the open circuit potential of the alloy was measured as a function of time. After corrosion test the specimens were examined by Scanning Electron Microscopy for the presence of pits. In another set of experiments potentiodynamic anodic polarization curves were used to determine the pitting potential of Incoloy 800 in deaerated NaCl solutions at chloride concentrations and pH values corresponding to those possessed by solutions containing 20 ppm to 20000 ppm CuCl 2 . At 60 degrees C pitting was observed in those solutions where the CuCl 2 concentration is higher than 1000 ppm. At 280 degrees C pitting was found in the specimens exposed to those solutions where the CuCl 2 concentration was higher than 20 ppm. (author). 3 refs

Annealing to Mitigate Pitting in Electropolished Niobium Coupons and SRF Cavities

Energy Technology Data Exchange (ETDEWEB)

Cooley, L.D.; Hahn, E.; Hicks, D.; Romanenko, A.; Schuessler, R.; Thompson, C.; /Fermilab

2011-06-08

Ongoing studies at Fermilab investigate whether dislocations and other factors instigate pitting during cavity electropolishing (EP), despite careful processing controls and the inherent leveling mechanism of EP itself. Here, cold-worked niobium coupons, which exhibited increased tendencies for pitting in our past study, were annealed in a high vacuum furnace and subsequently processed by EP. Laser confocal scanning microscopy and special defect counting algorithms were used to assess the population of pits formed. Hardness measurements indicated that annealing for 2 hours at 800 C produced recovery, whereas annealing for 12 hours at 600 C did not, as is consistent with known changes for cavities annealed in a similar way. The 800 C anneal was effective in some cases but not others, and we discuss reasons why tendencies for pitting remain. We discuss implications for cavities and continued work to understand pitting.

Congenital upper lip pit: A rare case report

Directory of Open Access Journals (Sweden)

Leena James

2015-01-01

Full Text Available One of the rarest developmental malformations of the lip is congenital lip pits. They are usually seen as bilateral depressions in the vermilion zone of the lip and occur on the paramedian portion of the vermilion border of the lip. They are extremely rare in the upper lip. Lip pits are due to the failure of complete union of embryonic lateral sulci of the lip/notching of lip at an early stage of development with fixation of tissues of the base of the notch. Lip pits have also been associated with a variety of other congenital disorders and other malformations. The clinical and pathologic picture and the therapeutic aspects of this condition are discussed in this paper.

Numerical Investigation on Stress Concentration of Tension Steel Bars with One or Two Corrosion Pits

Directory of Open Access Journals (Sweden)

Jian Hou

2015-01-01

Full Text Available Pitting corrosion has been observed in steel bars of existing reinforced concrete (RC structures in different erosion environments and has been identified as a potential origin for fatigue crack nucleation. In the present study, under uniaxial tension loading, stress distribution in the steel bars with one or two semiellipsoidal corrosion pits has systematically been investigated by conducting a series of three-dimensional semiellipsoidal pitted models. Based on the finite element analyses, it is shown that stress concentration factor (SCF increases linearly with increasing pit aspect ratio (a/b and increases nonlinearly with increasing pit relative depth (a/R for single corrosion pit problem. For double corrosion pits problem, the SCF decreases nonlinearly with increasing angle of two transverse pits (θ. The interaction of two longitudinal pits can be ignored in the calculation of SCF even if the distance of two pits (d is very small.

Railroad Rails Containing Electrode-Induced Pitting from Pressure Electric Welding

Science.gov (United States)

2018-04-18

This paper describes the forensic evaluations of three railroad rails containing electrode-induced pitting. These evaluations include: magnetic particle inspection to nondestructively detect cracks emanating from the pitting; fractography to study th...

Detailed investigation of current transients from metastable pitting events on stainless steel - the transition to stability

International Nuclear Information System (INIS)

Pistorius, P.C.; Burstein, G.T.

1992-01-01

Current transients which result from metastable pitting events (on Type 304 stainless steel in an acidic solution containing 1 M Cl - ) are presented. A criterion for the stable growth of open hemispherical pits is developed; the criterion states that the product of current density and pit depth must exceed a certain minimum value, to sustain rapid dissolution. Analysis of the transients from metastable pits shows that these pits fall short of this minimum, as do stable pits initially. The growth of these pits thus requires the presence of another barrier to diffusion, which is thought to be a remnant of the passive film; this forms a flawed cover over the pit mouth. When this cover ruptures under the influence of osmotic pressure, the pit repassivates. Pits growing at higher current densities approach the minimum requirement for stable growth more closely. A ''pitting potential'' results from the effect that metastable pits formed at more positive potentials grow at higher current densities, and are thus more likely to grow into stable pits. The effect of potential on the current density does not result from either activation control or ohmic control; rather, the pits grow under diffusion control. A change, with potential, of the type of pit site which can be activated, causes the potential dependence of the distribution of current densities in metastable pits. Although the distribution of current densities changes with potential, each metastable pit grows under diffusion control with a current density which is independent of the potential; this is confirmed by polarisation tests on growing metastable pits

Pit 9 project: A private sector initiative

International Nuclear Information System (INIS)

Macdonald, D.W.; Hughes, F.P.; Burton, B.N.

1993-01-01

This report discusses the Pit 9 Comprehensive Demonstration which is intended to demonstrate a cost-effective approach to remediate an Idaho National Engineering Laboratory (INEL) waste disposal pit through a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Interim Action. The remediation will include additional requirements, if needed, to provide high confidence that only minor additional work would be necessary to accomplish the final closure as part of the overall final closure strategy for the INEL's Subsurface Disposal Area (SDA)

Conceptual design of the handling and storage system for spent target vessel

Energy Technology Data Exchange (ETDEWEB)

Adachi, Junichi; Sasaki, Shinobu; Kaminaga, Masanori; Hino, Ryutaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-03-01

A conceptual design of a handling and storage system for spent target vessels has been carried out, in order to establish spent target technology for the neutron scattering facility. The spent target vessels must be treated remotely with high reliability and safety, since they are highly activated and contain the poisonous mercury. The system is composed of a target exchange trolley to exchange the target vessel, remote handling equipment such as manipulators, airtight casks for the spent target vessel, storage pits and so on. This report presents the results of conceptual design study on a basic plan, a handling procedure, main devices and their arrangement of a handling and storage system for the spent target vessels. (author)

Nucleation sites of Ge nanoislands grown on pit-patterned Si substrate prepared by electron-beam lithography

Science.gov (United States)

Smagina, Zh. V.; Zinovyev, V. A.; Rudin, S. A.; Novikov, P. L.; Rodyakina, E. E.; Dvurechenskii, A. V.

2018-04-01

Regular pit-patterned Si(001) substrates were prepared by electron-beam lithography followed by plasma chemical etching. The geometry of the pits was controlled by varying the etching conditions and the electron-beam exposure duration. It was shown that the location of three-dimensional (3D) Ge nanoislands subsequently grown on the pit-patterned Si substrates depends on the shape of the pit bottom. In the case of pits having a sharp bottom, 3D Ge islands nucleate inside the pits. For pits with a wide flat bottom, the 3D Ge island nucleation takes place at the pit periphery. This effect is attributed to the strain relaxation depending not only on the initial pit shape, but also on its evolution during the Ge wetting layer deposition. It was shown by Monte Carlo simulations that in the case of a pit with a pointed bottom, the relaxation is most effective inside the pit, while for a pit with a wide bottom, the most relaxed area migrates during Ge deposition from the pit bottom to its edges, where 3D Ge islands nucleate.

Pitting Corrosion Topography Characteristics and Evolution Laws of LC4 Aluminum Alloy in Service Environment

Directory of Open Access Journals (Sweden)

LIU Zhiguo

2017-08-01

Full Text Available Aircraft aluminum alloy is easy to initiate pitting corrosion in the service environment, the pitting corrosion topography characteristics could directly affect the fatigue mechanical property of structure material. In order to obtain the pitting corrosion topography characteristics of LC4 aluminum alloy in the service environment, the accelerated corrosion test was carried out along the accelerated corrosion test environment spectrum which imitated the service environment spectrum, and the corrosion topography characteristic parameters of corrosion pit depth H,corrosion pit surface length L and corrosion pit surface width W were defined respectively. During the corrosion test process,the three parameters of typical corrosion pit were successively measured in different equivalent corrosion years for obtaining the corrosion pit damage size data, then the data were analysed through the statistics method and fractal theory. Further more in order to gain the pit topography characteristics in the same equivalent corrosion year and the topography evolution laws during different equivalent corrosion years were gained. The analysis results indicate that LC4 aluminum alloy corrosion pit topography characteristics in the service environment include the following:firstly, the pit topography characteristic parameters conform to the lognormal distributions in the same equivalent corrosion years; secondly,the pit topography characteristic parameters gradually reflect the fractal feature in accordance with the equivalent corrosion year increment, and the pits tend to be shallow, long and moderate wide topography character.

Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse.

Science.gov (United States)

Vincent, Jean-Baptiste; Bodewits, Dennis; Besse, Sébastien; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; Keller, Horst Uwe; Agarwal, Jessica; A'Hearn, Michael F; Auger, Anne-Thérèse; Barucci, M Antonella; Bertaux, Jean-Loup; Bertini, Ivano; Capanna, Claire; Cremonese, Gabriele; Da Deppo, Vania; Davidsson, Björn; Debei, Stefano; De Cecco, Mariolino; El-Maarry, Mohamed Ramy; Ferri, Francesca; Fornasier, Sonia; Fulle, Marco; Gaskell, Robert; Giacomini, Lorenza; Groussin, Olivier; Guilbert-Lepoutre, Aurélie; Gutierrez-Marques, P; Gutiérrez, Pedro J; Güttler, Carsten; Hoekzema, Nick; Höfner, Sebastian; Hviid, Stubbe F; Ip, Wing-Huen; Jorda, Laurent; Knollenberg, Jörg; Kovacs, Gabor; Kramm, Rainer; Kührt, Ekkehard; Küppers, Michael; La Forgia, Fiorangela; Lara, Luisa M; Lazzarin, Monica; Lee, Vicky; Leyrat, Cédric; Lin, Zhong-Yi; Lopez Moreno, Josè J; Lowry, Stephen; Magrin, Sara; Maquet, Lucie; Marchi, Simone; Marzari, Francesco; Massironi, Matteo; Michalik, Harald; Moissl, Richard; Mottola, Stefano; Naletto, Giampiero; Oklay, Nilda; Pajola, Maurizio; Preusker, Frank; Scholten, Frank; Thomas, Nicolas; Toth, Imre; Tubiana, Cecilia

2015-07-02

Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.

Pump Hydro Energy Storage systems (PHES) in groundwater flooded quarries

Science.gov (United States)

Poulain, Angélique; de Dreuzy, Jean-Raynald; Goderniaux, Pascal

2018-04-01

Pump storage hydroelectricity is an efficient way to temporarily store energy. This technique requires to store temporarily a large volume of water in an upper reservoir, and to release it through turbines to the lower reservoir, to produce electricity. Recently, the idea of using old flooded quarries as a lower reservoir has been evoked. However, these flooded quarries are generally connected to unconfined aquifers. Consequently, pumping or injecting large volumes of water, within short time intervals, will have an impact on the adjacent aquifers. Conversely, water exchanges between the quarry and the aquifer may also influence the water level fluctuations in the lower reservoir. Using numerical modelling, this study investigates the interactions between generic flooded open pit quarries and adjacent unconfined aquifers, during various pump-storage cyclic stresses. The propagation of sinusoidal stresses in the adjacent porous media and the amplitude of water level fluctuations in the quarry are studied. Homogeneous rock media and the presence of fractures in the vicinity of the quarry are considered. Results show that hydrological quarry - rock interactions must be considered with caution, when implementing pump - storage systems. For rock media characterized by high hydraulic conductivity and porosity values, water volumes exchanges during cycles may affect significantly the amplitude of the water level fluctuations in the quarry, and as a consequence, the instantaneous electricity production. Regarding the impact of the pump - storage cyclic stresses on the surrounding environment, the distance of influence is potentially high under specific conditions, and is enhanced with the occurrence of rock heterogeneities, such as fractures. The impact around the quarry used as a lower reservoir thus appears as an important constraining factor regarding the feasibility of pump - storage systems, to be assessed carefully if groundwater level fluctuations around the quarry

Isochron measurements of naturally irradiated K-feldspar grains

International Nuclear Information System (INIS)

Li Bo; Li Shenghua; Wintle, Ann G.; Zhao Hui

2007-01-01

The equivalent doses of K-feldspar grains in a range of grain sizes from 90 to 250μm diameter were measured using a single-aliquot regenerative-dose protocol for the infrared stimulated luminescence (IRSL) signals for two samples of desert sand. The equivalent doses for each sample were compared with that for the 125-150μm grains of quartz from the same samples. The results suggested that the K-feldspar equivalent doses were underestimated because of anomalous fading. Measurements of the decay of the IRSL signals following laboratory irradiation for these two samples, and an additional one from a previously published isochron study, showed anomalous fading during the period of laboratory storage. The decay rate was about 3% per decade for all samples and was independent of the grain size used. Using plots of equivalent doses for K-feldspars as a function of their calculated internal dose rate, and the quartz equivalent dose as a function of grain size, it was concluded that the IRSL signal derived from the internal dose rate had not faded over the 13,000 years that had elapsed since the grains were deposited

Markov chain model helps predict pitting corrosion depth and rate in underground pipelines

Energy Technology Data Exchange (ETDEWEB)

Caleyo, F.; Velazquez, J.C.; Hallen, J. M. [ESIQIE, Instituto Politecnico Nacional, Mexico D. F. (Mexico); Esquivel-Amezcua, A. [PEMEX PEP Region Sur, Villahermosa, Tabasco (Mexico); Valor, A. [Universidad de la Habana, Vedado, La Habana (Cuba)

2010-07-01

Recent reports place pipeline corrosion costs in North America at seven billion dollars per year. Pitting corrosion causes the higher percentage of failures among other corrosion mechanisms. This has motivated multiple modelling studies to be focused on corrosion pitting of underground pipelines. In this study, a continuous-time, non-homogenous pure birth Markov chain serves to model external pitting corrosion in buried pipelines. The analytical solution of Kolmogorov's forward equations for this type of Markov process gives the transition probability function in a discrete space of pit depths. The transition probability function can be completely identified by making a correlation between the stochastic pit depth mean and the deterministic mean obtained experimentally. The model proposed in this study can be applied to pitting corrosion data from repeated in-line pipeline inspections. Case studies presented in this work show how pipeline inspection and maintenance planning can be improved by using the proposed Markovian model for pitting corrosion.

Norm Levels in Mine Pit Lakes in South-Western Spain

International Nuclear Information System (INIS)

Manjón, G.; Galván, J.; Mantero, J.; Díaz, I.; García-Tenorio, R.

2015-01-01

Former mining activities in a pyritic area in south-western Spain have generated mine pits in which underground water and rainwater has accumulated. The accumulated waters have produced oxidation of the pyrite and, consequently, the pit water has become acidic, causing the dissolution of metals and radionuclides of natural origin. The paper discusses the activity concentration levels of uranium isotopes and other radionuclides in water samples and sediments collected from these mine pit lakes. Tributaries of the nearby Odiel River, when crossing the mining area, show low pH values and high concentrations of uranium isotopes due to acid mine drainage. Through the analysis of several isotope activity ratios, the presence of radionuclides in the pit lakes and the influence of these radionuclides on the surrounding area and the Odiel River are evaluated. (author)

Numerical simulation of the double pits stress concentration in a curved casing inner surface

Directory of Open Access Journals (Sweden)

Wei Yan

2016-12-01

Full Text Available Sour or sweet oil fields development is common in recent years. Casing and tubing are usually subjected to pitting corrosion because of exposure to the strong corrosion species, such as CO2, H2S, and saline water. When the corrosion pits formed in the casing inner surface, localized stress concentration will occur and the casing strength will be degraded. Thus, it is essential to evaluate the degree of stress concentration factor accurately. This article performed a numerical simulation on double pits stress concentration factor in a curved inner surface using the finite element software ABAQUS. The results show that the stress concentration factor of double pits mainly depends on the ratio of two pits distance to the pit radius (L/R. It should not be only assessed by the absolute distance between the two pits. When the two pits are close and tangent, the maximum stress concentration factor will appear on the inner tangential edges. Stress concentration increased by double pits in a curved casing inner surface is more serious than that in a flat surface. A correction factor of 1.9 was recommended in the curved inner surface double pits stress concentration factor predict model.

Simulation of interim spent fuel storage system with discrete event model

International Nuclear Information System (INIS)

Yoon, Wan Ki; Song, Ki Chan; Lee, Jae Sol; Park, Hyun Soo

1989-01-01

This paper describes dynamic simulation of the spent fuel storage system which is described by statistical discrete event models. It visualizes flow and queue of system over time, assesses the operational performance of the system activities and establishes the system components and streams. It gives information on system organization and operation policy with reference to the design. System was tested and analyzed over a number of critical parameters to establish the optimal system. Workforce schedule and resources with long processing time dominate process. A combination of two workforce shifts a day and two cooling pits gives the optimal solution of storage system. Discrete system simulation is an useful tool to get information on optimal design and operation of the storage system. (Author)

Risks and mitigation options for on-site storage of wastewater from shale gas and tight oil development

International Nuclear Information System (INIS)

Kuwayama, Yusuke; Roeshot, Skyler; Krupnick, Alan; Richardson, Nathan; Mares, Jan

2017-01-01

We provide a critical review of existing research and information regarding the sources of risk associated with on-site shale gas and tight oil wastewater storage in the United States, the gaps that exist in knowledge regarding these risks, policy and technology options for addressing the risks, and the relative merits of those options. Specifically, we (a) identify the potential risks to human and ecological health associated with on-site storage of shale gas and tight oil wastewater via a literature survey and analysis of data on wastewater spills and regulatory violations, (b) provide a detailed description of government regulations or industry actions that may mitigate these risks to human and ecological health, and (c) provide a critical review of this information to help generate progress toward concrete action to make shale gas and tight oil development more sustainable and more acceptable to a skeptical public, while keeping costs down. - Highlights: • We review current research/information on shale gas and tight oil wastewater storage. • Pit overflows, tank overfills, and liner malfunctions are common spill causes. • Tanks lead to smaller and less frequent spills than pits, but are not a magic bullet. • State regulations for on-site oil and gas wastewater storage are very heterogeneous.

TRANSITIONS IN ELECTROCHEMICAL NOISE DURING PITTING CORROSION OF ALUMINUM IN CHLORIDE ENVIRONMENTS

International Nuclear Information System (INIS)

SASAKI, K.; ISAACS, H.S.; LEVY, P.W.

2001-01-01

Aluminum, in a chloride containing solutions close to its pitting potential, shows vigorous fluctuations in current and potential. Measurements have been made of the freely corroding potential, and the currents between interconnected electrodes. It is shown that there is a transition in the behavior of the transients. The transition occurs when multiple active pits are present and electrochemical communication occurs between them. The major source of current and potential transients is the growth process in the active pits rather than meta-stable pitting at the passive surface

TRANSITIONS IN ELECTROCHEMICAL NOISE DURING PITTING CORROSION OF ALUMINUM IN CHLORIDE ENVIRONMENTS.

Energy Technology Data Exchange (ETDEWEB)

SASAKI,K.; ISAACS,H.S.; LEVY,P.W.

2001-09-02

Aluminum, in a chloride containing solutions close to its pitting potential, shows vigorous fluctuations in current and potential. Measurements have been made of the freely corroding potential, and the currents between interconnected electrodes. It is shown that there is a transition in the behavior of the transients. The transition occurs when multiple active pits are present and electrochemical communication occurs between them. The major source of current and potential transients is the growth process in the active pits rather than meta-stable pitting at the passive surface.

Application of Surpac and Whittle Software in Open Pit Optimisation ...

African Journals Online (AJOL)

Application of Surpac and Whittle Software in Open Pit Optimisation and Design. ... This paper studies the Surpac and Whittle software and their application in designing an optimised pit. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

Pitting corrosion of zirconium in aqueous solution

International Nuclear Information System (INIS)

El Shayeb, H.A.; Abd El Wahab, F.M.; Abd Elk Meguid, E.A.

1994-01-01

The open circuit potentials of the Zr electrode are followed as a function of time in various aqueous solutions till attainment of steady state values.The results are discussed on the basis of oxide film thickening and repair. Pitting corrosion of Zr was examined in chloride solutions using the potentiodynamic technique. The effect of some inorganic and organic additives was also investigated for inhibiting the pitting corrosion of Zr and the relative performance is presented and discussed. (author). 21 refs., 6 figs., 1 tab

KDHE Project Code: C6-074-00002: Progress and Monitoring Report for the LDB/SVE/AS System at the Former CCC/USDA Grain Storage Facility, Agra, Kansas, in July-December 2015

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, Lorraine M. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-02-01

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at Agra, Kansas, from the 1950s to the early 1970s. No structures remain on the property, and the land is used for agricultural purposes, specifically wheat production. The property is currently owned by the Kyle Railroad Co. and is leased to Mr. Herb VanEaton. The Pro-Ag Marketing grain storage facility is directly south of the former CCC/USDA facility. Quarterly progress reports for October-December 2008, January-March 2009, and April- June 2009 (Argonne 2009a,b,c) provided detailed information regarding construction and startup of the cleanup. Previous periodic monitoring reports (Argonne 2010a,b,c,d, 2011a,b,c, 2012, 2013a,b,c, 2014a,b) have tracked the subsequent progress of the cleanup effort. Data for evaluation of system performance are collected primarily by sampling SVE effluents, soil gas monitoring points, and groundwater wells for analysis for volatile organic compounds (VOCs). Table 1.1 provides a detailed chronological summary of activities during implementation of the cleanup.

PIT Coating Requirements Analysis

International Nuclear Information System (INIS)

MINTEER, D.J.

2000-01-01

This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products

PIT Coating Requirements Analysis

Energy Technology Data Exchange (ETDEWEB)

MINTEER, D.J.

2000-10-20

This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

Pitting Corrosion Behaviour of New Corrosion-Resistant Reinforcement Bars in Chloride-Containing Concrete Pore Solution.

Science.gov (United States)

Jiang, Jin-Yang; Liu, Yao; Chu, Hong-Yan; Wang, Danqian; Ma, Han; Sun, Wei

2017-08-04

In this study, the pitting behaviour of a new corrosion-resistant alloy steel (CR) is compared to that of low-carbon steel (LC) in a simulated concrete pore solution with a chloride concentration of 5 mol/L. The electrochemical behaviour of the bars was characterised using linear polarisation resistance (LPR) and electrochemical impedance spectroscopy (EIS). The pitting profiles were detected by reflective digital holographic microscopy (DHM), scanning electron microscopy (SEM), and the chemical components produced in the pitting process were analysed by X-ray energy dispersive spectroscopy (EDS). The results show that the CR bars have a higher resistance to pitting corrosion than the LC bars. This is primarily because of the periodic occurrence of metastable pitting during pitting development. Compared to the pitting process in the LC bars, the pitting depth grows slowly in the CR bars, which greatly reduces the risk of pitting. The possible reason for this result is that the capability of the CR bars to heal the passivation film helps to restore the metastable pits to the passivation state.

Material characterization and corrosion control in wet storage of Chilean spent fuel

International Nuclear Information System (INIS)

Lamas, C.; Klein, J.; Escobar, I.

2002-01-01

Chile has two MTR type research reactors and the spent fuel will be stored in water previous to the conditioning for final disposal. One of the serious problem presented during wet storage is the phenomenon of corrosion, which depends on the water quality, the structural materials and the storage conditions. Thus, it is necessary to solve how to guarantee the integrity of the spent fuel during its wet storage. The water quality and fuel assembly materials are being characterized with the purpose to define the criteria of surveillance and control of corrosion as a function of time. The behavior of the 6061 Al and N4 Al alloys is being studied to characterize the susceptibility to pitting corrosion in solutions with chloride and cadmium as aggressive ions. The analyses were performed in a three-electrode electrochemical cell with 6061 Al and N4 Al as working electrodes. Platinum wire was the auxiliary electrode while Ag/AgCl was the reference electrode. To obtain the electrochemical characterization the polarization curves were used and the evolution of the corrosion potential of the aluminum alloys and SS 304 were measured. The electrolyte was deionized water with different concentrations of chloride and cadmium. At present, the results show that 6061 Al and N4 Al alloys are more susceptible to be attacked by pitting due to the presence of chloride than cadmium. (author)

A New Algorithm for Determining Ultimate Pit Limits Based on Network Optimization

Directory of Open Access Journals (Sweden)

Ali Asghar Khodayari

2013-12-01

Full Text Available One of the main concerns of the mining industry is to determine ultimate pit limits. Final pit is a collection of blocks, which can be removed with maximum profit while following restrictions on the slope of the mine’s walls. The size, location and final shape of an open-pit are very important in designing the location of waste dumps, stockpiles, processing plants, access roads and other surface facilities as well as in developing a production program. There are numerous methods for designing ultimate pit limits. Some of these methods, such as floating cone algorithm, are heuristic and do not guarantee to generate optimum pit limits. Other methods, like Lerchs–Grossmann algorithm, are rigorous and always generate the true optimum pit limits. In this paper, a new rigorous algorithm is introduced. The main logic in this method is that only positive blocks, which can pay costs of their overlying non-positive blocks, are able to appear in the final pit. Those costs may be paid either by positive block itself or jointly with other positive blocks, which have the same overlying negative blocks. This logic is formulated using a network model as a Linear Programming (LP problem. This algorithm can be applied to two- and three-dimension block models. Since there are many commercial programs available for solving LP problems, pit limits in large block models can be determined easily by using this method.

Mechanism of pitting corrosion prevention by nitrite in carbon steel exposed to dilute salt solutions. 1998 annual progress report

International Nuclear Information System (INIS)

Zapp, P.E.; Zee, J. van.

1998-01-01

'The overall goal of this project is to develop a fundamental understanding of the role of nitrite in preventing the breakdown of protective oxide(s) on carbon steel and the onset of pitting. Pitting corrosion of carbon steel exposed to dilute alkaline salt solutions can be induced by nitrate, sulfate, and chloride ions and is prevented by sufficient concentration of nitrite. A significant example of this material/electrolyte system is the storage and processing of DOE''s high-level radioactive liquid waste in carbon steel tanks. Added nitrite in the waste has a considerable downstream impact on the immobilization of the waste in a stable glass form. Waste tank integrity and glass production efficiency may benefit from the fundamental understanding of nitrite''s role in preventing pitting. This report summarizes progress after approximately six months of effort in this three-year EMSP project. Initial experimental and theoretical work has focused on the electrochemical behavior of carbon steel in simplified non-radioactive solutions that simulate complex dilute radioactive waste solutions. These solutions contain corrosion-inducing species such as nitrate and chloride and the corrosion-inhibiting nitrite at moderately alkaline pHs. The electrochemical behavior of interest here is that of the open-circuit potential of the steel specimen at equilibrium in the experimental electrolyte and the measures of the steel''s passivity and passivity breakdown.'

Production method of hydrogen storage alloy electrode and hydrogen storage alloy for rechageable battery; Suiso kyuzo gokin denkyoku oyobi chikudenchiyo suiso kyuzo gokin no seizo hoho

Energy Technology Data Exchange (ETDEWEB)

Mizutaki, F.; Ishimaru, M.

1995-04-07

This invention relates to the hydrogen storage alloy electrode in which the misch metal-nickel system hydrogen storage alloy is employed. The grain of the hydrogen storage alloy is controlled so as to reduce the dendrite cell size. Since the hydrogen storage alloy having such small dendrite cell size has no part where the metal structure is too brittle, the alloy has a sufficient mechanical strength. It can stand for the swell and shrink stress associated with the sorption and desorption of hydrogen. The disintegration, therefore, due to the cracking of the alloy is hardly to take place. In addition, the quenching of molten alloy at a cooling rate of 1000{degree}C/sec or faster suppresses the occurrence of segregation of any alloy element at the grain boundary, making it possible to produce the homogeneous and mechanically strong alloy. In other words, it can be achieved to produce a hydrogen storage alloy electrode having an excellent cycle property. 4 figs., 1 tab.

Analysis of two Pit-1 gene polymorphisms: Single nucleotide ...

African Journals Online (AJOL)

Pit-1 is a pituitary-specific transcription factor responsible for pituitary development and hormone expression in mammals. Pit-1 is a member of the POU domain containing proteins, a group of transcriptional regulators with a critical role in cell differentiation and proliferation. It was shown that this group of proteins control the ...

INFLUENCE OF PIT WALL ANCHORAGE ONTO ADDITIONAL DEFORMATIONS OF EXISTING BUILDINGS

Directory of Open Access Journals (Sweden)

Kubetskiy Valeriy Leonidovich

2012-07-01

Assessment of additional projected deformations of buildings located in close proximity to pits is exemplified by the specific structure of the pit support system that has active PIT [1] anchors. The authors also consider the influence produced by the structure of anchors onto the two buildings located within the area of influence of the excavation works and protected by the anchors installed underneath the foundations of the two adjacent buildings.

Investigation of cooling coil corrosion in storage tanks for radioactive waste

International Nuclear Information System (INIS)

Ondrejcin, R.S.

1978-01-01

The high frequency of cooling coil leaks observed in high-heat waste storage tanks soon after sludge removal operations is attributed to pitting, according to laboratory corrosion studies. Experiments show that the most likely series of events leading to coil leakage is (1) excessive dilution of basic nitrite in the supernate, (2) initiation of attack in crevices due to oxygen depletion cells, and (3) acceleration of the attack by sulfate dissolved from the sludge. When sludge was slurried with water, the interstitial liquid was diluted. Nitrite, the anodic inhibitor that prevented attack on coils and tanks in normal operation when its concentration was 0.5 to 3.0M, could accelerate attack when diluted to 10 -4 to 10 -3 M. Attack was presumably initiated at oxygen depletion cells. The presence of sulfate, leached from the sludge, produced a conductive solution that could produce high current densities at the corroding steel surface. The proposed series of events leading to coil leakage agrees with the observations previously made on one leaking coil removed from Tank 2F after sludge removal in 1967. Examination revealed pitting that had originated on the outside of the coils. This pitting was attributed to oxygen depletion cells in coil crevices. To prevent recurrence of pitting attack on cooling coils during future sludge removal operations, the sludge should be slurried (1) with waste diluted less than one hundredfold with water, or (2) with a 500-ppm nitrite-H 2 O solution at pH 12. Either method should preclude pitting damage to the coils

Critical pitting temperature for Type 254 SMO stainless steel in chloride solutions

International Nuclear Information System (INIS)

Abd El Meguid, E.A.; Abd El Latif, A.A.

2007-01-01

The variation with time of the open circuit potential of high molybdenum containing stainless steel (Type 254 SMO) was measured in 4% sodium chloride solution in the temperatures range 30-100 deg. C. The plot of steady state potentials as function of temperature showed an inflection at 50 deg. C, attributed to the decrease of oxygen solubility in test solution above 50 deg. C. Potentiodynamic cycling anodic polarization technique was used to determine the critical pitting potential (E pit ) and the critical protection potential (E prot ) of the steel in 4-30% NaCl solutions at temperatures between 30 and 100 deg. C. By plotting the two values versus solution temperature, the corresponding critical pitting (CPT) and the critical protection (CPrT) temperatures were determined. Both parameters decreased with increasing chloride content. Above the CPT, E pit and E prot decreased linearly with log[Cl - ]. The addition of bromide ions to the solution shifted both E pit and E prot towards positive values. In 4% NaCl, E pit increased linearly with pH in the range 1-10. The combined effect of chloride ion concentration and pH on the morphology of the pits was examined by scanning electron microscopy (SEM) following potentiodynamic cycling anodic polarization

Enhanced in vitro biocompatibility of ultrafine-grained titanium with hierarchical porous surface

International Nuclear Information System (INIS)

Zheng, C.Y.; Nie, F.L.; Zheng, Y.F.; Cheng, Y.; Wei, S.C.; Valiev, R.Z.

2011-01-01

Bulk ultrafine-grained Ti (UFG Ti) was successfully fabricated by equal-channel angular pressing (ECAP) technique in the present study, and to further improve its surface biocompatibility, surface modification techniques including sandblasting, acid etching and alkali treatment were employed to produce a hierarchical porous surface. The effect of the above surface treatments on the surface roughness, wettability, electrochemical corrosion behavior, apatite forming ability and cellular behavior of UFG Ti were systematically investigated with the coarse-grained Ti as control. Results show that UFG-Ti with surface modification had no pitting corrosion and presented low corrosion rate in simulated body fluids (SBF). The hierarchical porous surface yielded by surface modification enhanced the ability of UFG Ti to form a complete apatite layer when soaked in SBF and promoted osteoblast-like cells attachment and proliferation in vitro, which promises to have a significant impact on increasing bone-bonding ability and reducing healing time when implanted due to faster tissue integration.

The Solid Waste Transfer Pit an FFTF [Fast Flux Test Facility] station for fuel and reflector transfer

International Nuclear Information System (INIS)

Milewski, A.J.; Thomson, J.D.

1985-01-01

This paper describes the design aspects of a proposed FFTF facility called the Solid Waste Transfer Pit (SWTP). This new facility will be used as a transfer station for reflectors and/or low decay heat fuel assemblies when movement from the Fuel Storage Facility for sodium removal and subsequent reprocessing is to be accomplished. The SWTP utilizes a shielded cell cover with an integral manually-operated gate valve for top loading of a transfer vessel. The cost-effective design discussed herein provides a practical approach using state-of-the-art concepts while assuring safe and reliable operation

Inspecting a research reactor's control rod surface for pitting using a machine vision

International Nuclear Information System (INIS)

Tokuhiro, Akira T.; Vadakattu, Shreekanth

2005-01-01

Inspection for pits on the control rod is performed to study the degradation of the control rod material which helps estimating the service life of the control rod at UMR nuclear reactor (UMRR). This inspection task is visually inspected and recorded subjectively. The conventional visual inspection to identify pits on the control rod surface can be automated using machine vision technique. Since the in-service control rods were not available to capture images and measure number of pits and size of the pits, the applicability of machine vision method was applied on SAE 1018 steel coupons immersed in oxygen saturated de-ionized water at 30deg, 50deg and 70deg. Images were captured after each test cycle at different light intensity to reveal surface topography of the coupon surface and analyzed for number of pits and pit size using EPIX XCAP-Std software. The captured and analyzed images provided quantitative results for the steel coupons and demonstrated that the method can be applied for identifying pits on control rod surface in place of conventional visual inspection. (author)

Initiation and inhibition of pitting corrosion on reinforcing steel under natural corrosion conditions

Energy Technology Data Exchange (ETDEWEB)

Abd El Wanees, S., E-mail: s_wanees@yahoo.com [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Bahgat Radwan, A. [Center for Advanced Materials, Qatar University, Doha 2713 (Qatar); Alsharif, M.A. [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Abd El Haleem, S.M. [Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt)

2017-04-01

Initiation and inhibition of pitting corrosion on reinforcing steel in saturated, naturally aerated Ca(OH){sub 2} solutions, under natural corrosion conditions, are followed through measurements of corrosion current, electrochemical impedance spectroscopy and SEM investigation. Induction period for pit initiation and limiting corrosion current for pit propagation are found to depend on aggressive salt anion and cation-types, as well as, concentration. Ammonium chlorides and sulfates are more corrosive than the corresponding sodium salts. Benzotriazole and two of its derivatives are found to be good inhibitors for pitting corrosion of reinforcing steel. Adsorption of these compounds follows a Langmuir adsorption isotherm. The thermodynamic functions ΔE{sup ∗}, ΔH{sup ∗} and ΔS{sup ∗} for pitting corrosion processes in the absence and presence of inhibitor are calculated and discussed. - Highlights: • Cl{sup −} and SO{sub 4} {sup 2-} induce pitting corrosion on passive reinforcing steel. • Initiation and propagation of pitting depend on cation and anion types. • Inhibition is based on adsorption according to Langmuir isotherm.

Pit membranes of Ephedra resemble gymnosperms more than angiosperms

Science.gov (United States)

Roland Dute; Lauren Bowen; Sarah Schier; Alexa Vevon; Troy Best; Maria Auad; Thomas Elder; Pauline Bouche; Steven Jansen

2014-01-01

Bordered pit pairs of Ephedra species were characterized using different types of microscopy. Pit membranes contained tori that did not stain for lignin. SEM and AFM views of the torus surface showed no plasmodesmatal openings, but branched, secondary plasmodesmata were occasionally noted using TEM in conjunction with ultrathin sections. The margo consisted of radial...

Formation of primary pit connection during conchocelis phase of Porphyra yezoensis (Bangiophyceae, Rhodophyta)

Science.gov (United States)

Shual, Li; Jiang, Ming; Duan, Delin

2006-09-01

The formation of pit connection during conchocelis phase of Porphyra yezoensis Ueda was observed and examined with transmission electron microscope (TEM) and epifluorence microscope. It is indicated that the pit connection was formed in late stage of conchocelis phase and the early stages of conchosporangial cell development, and disappeared in bispore stage. The pit connection contained a thin membrane layer at outer pit plug. Stained with 4', 6'-diamidino-2-phenylidole dihydrochloride hydrate (DAPI), transferring of DNA or RNA between adjacent cells were observed in late stage of conchocelis development, it was deduced that pit connection might serve as a channel for signal transduction and genetic substance transportation in conchocelis phase.

New diagnostic technology and hidden pits and fissures caries

Directory of Open Access Journals (Sweden)

Fabrizio Guerra

2015-10-01

Full Text Available The accuracy in pits and fissures caries detection is of paramount importance in dental caries primary and secondary prevention. A combination of visual examination and probing is currently the mainstay of occlusal caries diagnosis. Unfortunately, these types of inspection alone may leave a certain number of pit and fissure caries undetected. The Vista Cam iX fluorescence camera (Durr Dental, Bietigheim-Bissingen, Germany is a novel dental diagnostic tool for quantitative assessment of dental caries with high specificity for carious lesions detection. In the presented cases photographic images, representing the visual diagnostic approach, are applied as integration to VistaCam iX Proof images. A step-by-step sequence of inspection and assessment of operative treatment need is presented in a case of hidden pit and fissure caries on a permanent molar. Based on the reported case, it could be observed that VistaCam iX Proof shows promising results in hidden pits and fissures caries detection and could be considered a non-invasive examination method that facilitate the detection of early lesions and a potential diagnostic aid.

Remedial Action Work Plan Amchitka Island Mud Pit Closures

Energy Technology Data Exchange (ETDEWEB)

DOE/NV

2001-04-05

This remedial action work plan presents the project organization and construction procedures developed for the performance of the remedial actions at U.S. Department of Energy (DOE's) sites on Amchitka Island, Alaska. During the late1960s and early 1970s, the U.S. Department of Defense and the U.S. Atomic Energy Commission (the predecessor agency to DOE) used Amchitka Island as a site for underground nuclear tests. A total of nine sites on the Island were considered for nuclear testing; however, tests were only conducted at three sites (i.e., Long Shot in 1965, Milrow in 1969, and Cannikin in 1971). In addition to these three sites, large diameter emplacement holes were drilled in two other locations (Sites D and F) and an exploratory hole was in a third location (Site E). It was estimated that approximately 195 acres were disturbed by drilling or preparation for drilling in conjunction with these activities. The disturbed areas include access roads, spoil-disposal areas, mud pits which have impacted the environment, and an underground storage tank at the hot mix plant which was used to support asphalt-paving operations on the island. The remedial action objective for Amchitka Island is to eliminate human and ecological exposure to contaminants by capping drilling mud pits, removing the tank contents, and closing the tank in place. The remedial actions will meet State of Alaska regulations, U.S. Fish and Wildlife Service refuge management goals, address stakeholder concerns, and address the cultural beliefs and practices of the native people. The U.S. Department of Energy, Nevada Operations Office will conduct work on Amchitka Island under the authority of the Comprehensive Emergency Response, Compensation, and Liability Act. Field activities are scheduled to take place May through September 2001. The results of these activities will be presented in a subsequent Closure Report.

200 West Ash Pit Demolition Site closure plan

International Nuclear Information System (INIS)

1992-11-01

The Hanford Facility is owned by the US Government and operated by the US Department of Energy, Richland Field Office. Dangerous waste and mixed waste (containing both radioactive and dangerous components) are managed and produced on the Hanford Facility. Westinghouse Hanford Company is a major contractor to the US Department of Energy, Richland Field Office and serves as cooperator of the 200 West Ash Pit Demolition Site, the unit addressed in this closure plan. The 200 West Ash Pit Demolition Site Closure Plan consists of a Part A Permit Application (Revision 3) and a closure plan. An explanation of the Part A Permit Application revision is provided at the beginning of the Part A section. The closure plan consists of nine chapters and three appendices. This 200 West Ash Pit Demolition Site Closure Plan submittal contains information current as of October 15, 1992

Temporal changes in stored-product insect populations associated with boot, pit, and load-out areas of grain elevators and feed mills

Science.gov (United States)

Commercial grain elevator and feed mill facilities can quickly become infested with stored-product insect pests, compromising the protection of the raw and processed cereal products stored at each facility type. Grain facilities of each type were sampled monthly for adults of stored-product insects ...

Control of ergosterol producer fungi contaminating cereal grains by certain environmental conditions and gamma rays

International Nuclear Information System (INIS)

Shahin, A.A.M.

2007-01-01

Existence of ergosterol in grains usually gives an indication that these grains are contaminated by ergosterol producing fungi. So, ergosterol concentration could be a suitable marker for estimation of fungal contamination range in cereal grains. Thirty eight fungal isolates were isolated from maize, sorghum and barley grains. Alternaria, Cladosporium and Aspergillus were the most common fungal genera among these isolates and they were tested for ergosterol production. The highest ergosterol producing fungi were identified as Alternaria alternaria, Cladosporium herbarum and Aspergillus niger var.niger. The present results indicate that the most suitable conditions for producing ergosterol by these strains in maize grains were found to be at 25 degree C for 30 days. Exposing the artificially contaminated maize grains by the above three strains (10 7 CFU/ml) to increasing dose levels of gamma rays up to 10 kGy and storing for 30 days, gradually decreased the production of ergosterol to 7.9, 6.2 and 1.5 mg/g dry weight of grains by A. alternata and C.herbarum and A. niger var. niger, respectively. D 10 values of the tested three isolates in maize grains were found to be 2, 1.61, and 1.2 kGy, respectively. The results showed that cold storage (10 degree C) clearly decreased the activity of the tested fungi for producing ergosterol during the storage periods, and a dose level of 15 kGy was quite enough to free the grains from A. alternata, Cladosporium herbarum and A. niger var. niger, regardless the contamination level of grains with these ergosterol producer fungus

Ecological geology environmental assessment of open-pit mines

International Nuclear Information System (INIS)

Dong Shuangfa; Jiang Xue

2010-01-01

In this paper, there is a detail description of ecological geology environmental assessment of open-pit mines, including method, process and results. We took ecological geology environmental assessment work on the base of the results of some open-pit mines such as extremely low content magnetite in Hebei Province, inducted and summarized the ecological geology environment quality. The results are reasonable. It provides basic data for the second mines programming in Hebei Province. (authors)

The Effects of Storage on Germination Characteristics and Enzyme Activity of Sorghum Seeds

Directory of Open Access Journals (Sweden)

Azadi M.S.

2013-11-01

Full Text Available Seed moisture content (MC and storage temperature are the most important factors affecting seed longevity and vigor. Exposure to warm, moist air is principally responsible for this. Proper storage and optimum seed moisture content can affect the grain quality significantly. The purpose of this study was to evaluate the different storage treatments on seed quality of sorghum. The seed materials were fresh without any storage period. For storage treatments, 3 seed moisture contents (6, 10, 14 % were stored for 8 month in 0.5 L capacity sealed aluminum foil packet in 0.3 bar inside incubators set at 4 temperatures (5, 15, 25, 35 °C. After storage time, the higher the storage temperature, the lower was the grain quality of sorghum. The highest germination percentage, germination index, normal seedling percentage were achieved in control conditions (0 day of storage. Our results showed that increasing storage duration resulted higher reduction in germination characteristics. Also our results showed that, germination percentage, means time to germination, germination index, normal seedling percentage decrease significantly by storage. Enzyme activity decrease significantly by increased in storage.

[Extrinsic and intrinsic factors associated with mycotoxigenic fungi populations of maize grains (Zea mays L.) stored in silobags in Argentina].

Science.gov (United States)

Castellari, Claudia C; Cendoya, María G; Marcos Valle, Facundo J; Barrera, Viviana; Pacin, Ana M

2015-01-01

In order to determine the behavior of mycotoxin-producing fungal populations linked with silobags stored corn grains with a moisture content greater at the recommended as safe, 270 samples taken in three times (beginning, 90 days, final) over a five month period of storage were evaluated. The fungal biota was quantified and identified and the contamination with fumonisin and aflatoxin was determined. Extrinsic factors (environment), intrinsic factors (grains) and technological factors (location of the grains in the profile of silobag) were taken into account to evaluate the presence and quantity of total and mycotoxigenic fungal populations. The pH of grains and O2 levels were significantly reduced after five months, while CO2 concentration increased in the same period. The total counts of mycobiota were significantly higher in grains located in the top layer of silobag. Mycotoxigenic species of Fusarium, Aspergillus, Penicillium and Eurotium were identified. The frequency of isolation of Fusarium verticillioides decreased at the end of storage and Aspergillus flavus was isolated only at the beginning of storage. The counts of the Penicillium spp. and Eurotium spp. were increased at the end of storage. Fumonisin contamination was found in all the samples (100%) with maximum levels of 5.707mg/kg whereas aflatoxin contaminated only 40% with maximum levels of 0.0008mg/kg. The environmental and substrate conditions generated during the storage limited the development of mycotoxigenic fungi and mycotoxin production. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Micro pit formation by mercury-sphere collision

International Nuclear Information System (INIS)

Ishikura, Syuichi; Kogawa, Hiroyuki; Futakawa, Masatoshi; Kaminaga, Masanori; Hino, Ryutaro

2004-01-01

The development of a MW-class spallation neutron source facility is being carried out under the Japan Proton Accelerator Research Complex (J-PARC) Project promoted by JAERI and KEK. A mercury target working as the spallation neutron source will be subjected to pressure waves generated by rapid thermal expansion of mercury due to a pulsed proton beam injection. The pressure wave will impose dynamic stress on the vessel and deform the vessel, which would cause cavitation in mercury. To evaluate the effect of mercury micro jets, driven by cavitation bubble collapse, on the micro-pit formation, analyses on mercury sphere collision were carried out: single bubble dynamics and collision behavior on interface between liquid and solid, which take the nonlinearity due to shock wave in mercury and the strain rate dependency of yield stress in solid metal into account. Analytical results give a good explanation to understand relationship between the micro-pit formation and material properties: the pit size could decrease with increasing the yield strength of materials. (author)

Relationship between foveal cone specialization and pit morphology in albinism.

Science.gov (United States)

Wilk, Melissa A; McAllister, John T; Cooper, Robert F; Dubis, Adam M; Patitucci, Teresa N; Summerfelt, Phyllis; Anderson, Jennifer L; Stepien, Kimberly E; Costakos, Deborah M; Connor, Thomas B; Wirostko, William J; Chiang, Pei-Wen; Dubra, Alfredo; Curcio, Christine A; Brilliant, Murray H; Summers, C Gail; Carroll, Joseph

2014-05-20

Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism. We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects underwent imaging with adaptive optics scanning light ophthalmoscopy (AOSLO), and cone density was measured. We found mutations in 22 of 25 subjects, including five novel mutations. All subjects lacked complete excavation of inner retinal layers at the fovea, though four subjects had foveal pits with normal diameter and/or volume. Peak cone density and OS lengthening were variable and overlapped with that observed in normal controls. A fifth hyper-reflective band was observed in the outer retina on SD-OCT in the majority of the subjects with albinism. Foveal cone specialization and pit morphology vary greatly in albinism. Normal cone packing was observed in the absence of a foveal pit, suggesting a pit is not required for packing to occur. The degree to which retinal anatomy correlates with genotype or visual function remains unclear, and future examination of larger patient groups will provide important insight on this issue. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Construction of an individualized temporary storage in CN ASCO

International Nuclear Information System (INIS)

Massuet Vilamajo, J.; Nunez Marfil, M.

2012-01-01

The design requirements of concrete shielding of storage containers, with limitation in the minimum density of the concrete, have forced the use of aggregates of high density (magnetite) and a feedback control of the dosage used depending on the characteristics obtained in the concrete plant. Likewise, high density Assembly into the pit of transfer along with the presence of a large metallic inner linner, has behaved the need to use innovative methods of galvanized and joint of reinforcement bars.

Optimizing the physical conditioning of the NASCAR sprint cup pit crew athlete.

Science.gov (United States)

Ferguson, David P; Davis, Adam M; Lightfoot, J Timothy

2015-03-01

Stock car racing is the largest spectator sport in the United States. As a result, National Association for Stock Car Automobile Racing (NASCAR) Sprint Cup teams have begun to invest in strength and conditioning programs for their pit crew athletes. However, there is limited knowledge regarding the physical characteristics of elite NASCAR pit crew athletes, how the NASCAR Sprint Cup season affects basic physiological parameters such as body composition, and what is the most appropriate physical training program that meets the needs of a pit crew athlete. We conducted 3 experiments involving Sprint Cup motorsport athletes to determine predictors of success at the elite level, seasonal physiological changes, and appropriate physical training programs. Our results showed that hamstring flexibility (p = 0.015) and the score on the 2-tire front run test (p = 0.012) were significant predictors of NASCAR Sprint Cup Pit Crew athlete performance. Additionally, during the off season, pit crew athletes lost lean body mass, which did not return until the middle of the season. Therefore, a strength and conditioning program was developed to optimize pit crew athlete performance throughout the season. Implementation of this strength and conditioning program in 1 NASCAR Sprint Cup team demonstrated that pit crew athletes were able to prevent lean body mass loss and have increased muscle power output from the start of the season to the end of the season.

Aflatoxin B1 and total fumonisin contamination and their producing fungi in fresh and stored sorghum grain in East Hararghe, Ethiopia.

Science.gov (United States)

Taye, Wondimeneh; Ayalew, Amare; Chala, Alemayehu; Dejene, Mashilla

2016-12-01

Natural contamination of sorghum grains by aflatoxin B 1 and total fumonisin and their producing toxigenic fungi has been studied. A total of 90 sorghum grain samples were collected from small-scale farmers' threshing floors and 5-6 months later from underground pits during 2013 harvest from three districts of East Hararghe, Ethiopia. Mycotoxin analysis was done using enzyme-linked immunosorbent assay (ELISA). The limits of detection were in the range 0.01-0.03 μg kg -1 . The results revealed that all sorghum grain samples were contaminated with both Aspergillus and Fusarium species. Aflatoxin B 1 was detected at levels ranging from fumonisin levels varied between 907 and 2041 µg kg -1 grain across the samples. Lowest total fumonisin was recorded in freshly harvested sorghum grain samples. Sorghum is a main staple cereal in the studied districts and its consumption per day per person is high. Daily intake of low doses of mycotoxin-contaminated food stuff over a period of time could lead to chronic mycotoxicosis.

The phenomenon of prehistoric ritual pits: Several examples from the central Balkans

Directory of Open Access Journals (Sweden)

Bulatović Aleksandar P.

2015-01-01

Full Text Available In recent years, the phenomenon of pits with special deposits, i.e. ritual pits, seems to have, once again, attracted attention both in Europe and in the Balkans. In the central Balkans, scientific literature related to this topic is still deficient, hence one of the objectives of this paper is to change the current state and rekindle interest in the study of this form of manifestation of the spiritual culture of prehistoric man. It appears that one of the oldest reasons for sacrificial offerings is primal, instinctive fear. The fear of the transience of life or of death compelled our ancient ancestors to make some sort of “agreement” with the surrounding forces, bestowing particular sacrifices onto them. Sacrifice represents one of the rituals of prehistoric communities which could have been performed in a number of ways and in different circumstances. One of these are offerings placed in pits, in the form of specific objects, food, drink or living beings sacrificed to higher powers and accompanied by certain symbolic actions, for the purpose of gaining their favour or help. When interpreting pits, what should further be considered is that the fundamental difference between a discarded object and an object used for a ritual purpose lies in the fact that the object of ritual character is still meaningful to man, performing a symbolic function, unlike the former, whose role is lost after being disposed of. Aritual object, an item or a living being sacrificed in a pit, is no longer of common, worldly significance (food, drink, tools, etc., but rather possesses a symbolic, sacral meaning, intended for higher powers, to propitiate and appease them, that is to create some form of the oldest religious communication. Not only is it difficult to identify the pits used for ritual purposes in the course of fieldwork, but it is even more challenging to interpret them and practically impossible to accurately reconstruct the actions performed during the

Herniation pits of the femur neck: incidence and radiologic findings

International Nuclear Information System (INIS)

Cho, Jae Hyun; Suh, Jin Suk; Lee, Hye Yeon

1994-01-01

In order to assess the incidence and radiologic findings of herniation pit of the femur neck in Korean. In 152 macerated femurs of 88 cadavers, and randomly selected 115 hips of 70 patients, the presence of herniation pit was determined by using fluoroscopy and radiography. It was then examined by CT for inspection of overlying surface and its opening was confirmed by inserting thin steal wire under the fluoroscopic guidance. Seventeen herniation pits in 15 macerated femurs of 13 cadavers were noted. (14.8%, 13/88). Two of 13 individuals showed bilaterality. All lesions were found only in males. Six herniation pit in 6 femurs of 6 patients (8.6%, 6/70) were also noted. All lesions were on anterosuperior aspect of femur neck. Plain radiographs of macerated femurs revealed well marginated and thin sclerosis in 15 lesions. Of all 23 lesions, CT showed cortical breakdown in 3, and overlying cortical thickening in 8. In 15 macerated femurs, roughed area of cortex was found in anterosuperior aspect of femur in all cases, and tiny openings(diameter less than 1 mm) related to cystic lesions were confirmed in 9 lesions. The incidence of herniation pits was 14.8% in 88 cadaver, and 8.6% in 70 patients. All were males

Corrective Action Decision Document for Corrective Action Unit 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site, Nevada: Revision No. 0

Energy Technology Data Exchange (ETDEWEB)

U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office

2003-10-17

This Corrective Action Decision Document identifies and rationalizes the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office's selection of a recommended corrective action alternative appropriate to facilitate the closure of Corrective Action Unit (CAU) 140: Waste Dumps, Burn Pits, and Storage Area, Nevada Test Site (NTS), Nevada, under the Federal Facility Agreement and Consent Order. Located in Areas 5, 22, and 23 of the NTS, CAU 140 consists of nine corrective action sites (CASs). Investigation activities were performed from November 13 through December 11, 2002, with additional sampling to delineate the extent of contaminants of concern (COCs) conducted on February 4 and March 18 and 19, 2003. Results obtained from the investigation activities and sampling indicated that only 3 of the 9 CASs at CAU 140 had COCs identified. Following a review of existing data, future land use, and current operations at the NTS, the following preferred alternatives were developed for consideration: (1) No Further Action - six CASs (05-08-02, 05-17-01, 05-19-01, 05-35-01, 05-99-04, and 22-99-04); (2) Clean Closure - one CAS (05-08-01), and (3) Closure-in-Place - two CASs (05-23-01 and 23-17-01). These alternatives were judged to meet all requirements for the technical components evaluated. Additionally, the alternatives meet all applicable state and federal regulations for closure of the site and will eliminate potential future exposure pathways to the contaminated media at CAU 140.

Investigation of the pitting of aluminum induced by chloride ions by holographic microphotography

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LIANG LI

2008-05-01

Full Text Available Holographic microphotography was used to investigate the dynamic processes of pitting during anodic dissolution of aluminum in a solution containing chloride ions. The induction and the follow-up propagation processes of the pitting were observed in real-time. A simple model of the propagating process of the pitting was deduced from the result of the holograms of the Al/electrolyte interface. The results prove that holographic microphotography is a useful tool to study the dynamic processes of pitting.

Dependence of Crystallographic Orientation on Pitting Corrosion Behavior of Ni-Fe-Cr Alloy 028

Science.gov (United States)

Zhang, LiNa; Szpunar, Jerzy A.; Dong, JianXin; Ojo, Olanrewaju A.; Wang, Xu

2018-03-01

The influence of crystallographic orientation on the pitting corrosion behavior of Ni-Fe-Cr alloy 028 was studied using a combination of X-ray diffraction (XRD), electron backscatter diffraction (EBSD), potentiodynamic polarization technique, and atomic force microscopy (AFM). The results show that there is anisotropy of pitting corrosion that strongly depends on crystallographic orientation of the surface plane. The distribution of pit density in a standard stereographic triangle indicates that the crystallographic planes close to {100} are more prone to pitting corrosion compared to planes {110} and {111}. The surface energy calculation of (001) and (111) shows that the plane with a high atomic packing density has a low surface energy with concomitant strong resistance to pitting corrosion. A correlation function between crystallographic orientation and pitting corrosion susceptibility suggests a method that not only predicts the pitting resistance of known textured materials, but also could help to improve corrosion resistance by controlling material texture.

Stochastic modeling of inspection uncertainties and applications to pitting flaws in steam generator tubes

International Nuclear Information System (INIS)

Mao, D.; Yuan, X.-X.; Pandey, M.D.

2009-01-01

Steam generators (SG) are a major pressure retaining component of great safety significance in nuclear power plants. Due to various manufacturing, operation and maintenance activities, as well as material interaction with the surrounding chemical environment, the SG tubes have been subject to a number of degradation modes. Among them, the under-deposit pitting corrosion at outside surfaces of the SG tubes just on top of the tubesheet support plates has had a serious impact on the integrity of the SG tubes. This paper presents an advanced probabilistic model of pitting corrosion characterizing the inherent randomness of the pitting process and measurement uncertainties of the in-service inspection (ISI) data obtained from eddy current (EC) inspections. A Bayesian method based on Markov Chain Monte Carlo (MCMC) simulation is developed for estimating the model parameters. The proposed model is able to predict the actual pit number, the actual pit depth as well as the maximum pit depth, which is the main interest of the pitting corrosion model. (author)

Open pit mining of uranium

International Nuclear Information System (INIS)

Wood, J.T.

1977-01-01

The Jackpile--Paquate Mines of the Anaconda Company are on the Laguna Indian Reservation midway between Grants and Albuquerque, New Mexico. The open pit mining of uranium ore at those mines is conducted in three separate operations (stripping, mining, and ore haul)

Creating Nanoscale Pits on Solid Surfaces in Aqueous Environment with Scanning Tunnelling Microscopy

DEFF Research Database (Denmark)

Chi, Qijin; Zhang, Jingdong; Friis, Esben P.

2000-01-01

of the pits can be controlled well in aqueous environments, and the operations are simple. Parameters affecting the pit formation and size have been systematically characterized to show that pit formation is dominated by bias voltage. A mechanism is proposed based on local surface reconstruction induced...

Numerical Simulation of Interactions between Corrosion Pits on Stainless Steel under Loading Conditions

International Nuclear Information System (INIS)

Wang, Haitao; Han, En-Hou

2017-01-01

The interactions between corrosion pits on stainless steel under loading conditions are studied by using a cellular automata model coupled with finite element method at a mesoscopic scale. The cellular automata model focuses on a metal/film/electrolyte system, including anodic dissolution, passivation, diffusion of hydrogen ions and salt film hydrolysis. The Chopard block algorithm is used to improve the diffusion simulation efficiency. The finite element method is used to calculate the stress concentration on the pit surface during pit growth, and the effect of local stress and strain on anodic current is obtained by using the Gutman model, which is used as the boundary conditions of the cellular automata model. The transient current characteristics of the interactions between corrosion pits under different simulation factors including the breakdown of the passive film at the pit mouth and the diffusion of hydrogen ions are analyzed. The analysis of the pit stability product shows that the simulation results are close to the experimental conclusions.

Electronic structures of GeSi nanoislands grown on pit-patterned Si(001 substrate

Directory of Open Access Journals (Sweden)

Han Ye

2014-11-01

Full Text Available Patterning pit on Si(001 substrate prior to Ge deposition is an important approach to achieve GeSi nanoislands with high ordering and size uniformity. In present work, the electronic structures of realistic uncapped pyramid, dome, barn and cupola nanoislands grown in {105} pits are systematically investigated by solving Schrödinger equation for heavy-hole, which resorts to inhomogeneous strain distribution and nonlinear composition-dependent band parameters. Uniform, partitioned and equilibrium composition profile (CP in nanoisland and inverted pyramid structure are simulated separately. We demonstrate the huge impact of composition profile on localization of heavy-hole: wave function of ground state is confined near pit facets for uniform CP, at bottom of nanoisland for partitioned CP and at top of nanoisland for equilibrium CP. Moreover, such localization is gradually compromised by the size effect as pit filling ratio or pit size decreases. The results pave the fundamental guideline of designing nanoislands on pit-patterned substrates for desired applications.

Numerical Simulation of Interactions between Corrosion Pits on Stainless Steel under Loading Conditions

Energy Technology Data Exchange (ETDEWEB)

Wang, Haitao; Han, En-Hou [Chinese Academy of Sciences, Shenyang (China)

2017-04-15

The interactions between corrosion pits on stainless steel under loading conditions are studied by using a cellular automata model coupled with finite element method at a mesoscopic scale. The cellular automata model focuses on a metal/film/electrolyte system, including anodic dissolution, passivation, diffusion of hydrogen ions and salt film hydrolysis. The Chopard block algorithm is used to improve the diffusion simulation efficiency. The finite element method is used to calculate the stress concentration on the pit surface during pit growth, and the effect of local stress and strain on anodic current is obtained by using the Gutman model, which is used as the boundary conditions of the cellular automata model. The transient current characteristics of the interactions between corrosion pits under different simulation factors including the breakdown of the passive film at the pit mouth and the diffusion of hydrogen ions are analyzed. The analysis of the pit stability product shows that the simulation results are close to the experimental conclusions.

Evaluation of the use of organic acids in the conservation of sorghum grains (Sorghum bicolor L. Moench during storage/ Avaliação do uso de ácidos orgânicos na conservação de grãos de sorgo (Sorghum bicolor L. Moench durante o armazenamento

Directory of Open Access Journals (Sweden)

Marcelo Zafalon Peter

2008-08-01

Full Text Available The objective of this work was to study the use of organic acids in storage of sorghum grains, as an efficient alternative for small and medium producers, that lack structures for artificial drying and technical storage. The grains were stored in bulk in wood boxes, for six months, consisting of five treatments: I dried grains (13.15% of moisture, without incorporation of acids; II humid grains (21,54% of moisture without incorporation of acids; II-A; II-P and II-M, the latter three, with incorporation of acetic acid, propionic and the mixture of both, in the proportion of 1:1, respectively, in the dosis of 2 kg of acid per 100 kg of grains. Evaluation of grains was made at 1, 60, 120 and 180 days of storage, analysing humidity, carboydrate, crude protein, ether extract, ash, volumetric weight and incidence of insects. For the storage of 180 days, under the same environment conditions, it is concluded that: 1 the incorporation of acids at the moment of storage of humid sorghum grains allows superior preservative effects when compared to dry grains; 2 the mixture of acids, showed superior quantitative and qualitative preservative effects of the grains, followed by propionic acid, and acetic, respectively; 3 the storage of humid grains, without addition of acids, does not allow adequate grain conservation, not even for a period lesser than 60 days.O objetivo deste trabalho foi estudar a utilização de ácidos orgânicos no armazenamento de grãos de sorgo, como alternativa eficiente para pequenos e médios produtores, que não dispõem de estruturas de secagem artificial e armazenamento tecnificado. Os grãos foram armazenados a granel, em caixas de madeira, por seis meses, consistindo de cinco tratamentos: I grãos secos (13,15% de umidade, sem incorporação de ácidos; II grãos úmidos (21,54% de umidade, sem incorporação de ácidos; II-A; II-P e II-M, sendo os três últimos grãos úmidos (21,54% de umidade, com incorporação de �

The Use of Pit and Fissure Sealants—A Literature Review

Directory of Open Access Journals (Sweden)

Reem Naaman

2017-12-01

Full Text Available This paper reviews the literature and discusses the latest updates on the use of pit and fissure sealants. It demonstrates the effectiveness of pit and fissure sealants in preventing caries and the management of early carious lesions. It compares the use of different sealant materials and their indications. It describes the application technique for sealants. It also reviews the cost-effectiveness of sealants as a preventive strategy. From this review and after the discussion of recently published studies on pit and fissure sealants, it is evident that sealants are effective in caries prevention and in preventing the progression of incipient lesions. It is therefore recommended that pit and fissure sealant be applied to high-caries-risk children for optimum cost-effectiveness. It is a highly sensitive technique that needs optimum isolation, cleaning of the tooth surface, etching, and the application of a thin bonding layer for maximum benefit. Recall and repair, when needed, are important to maximize the effectiveness of such sealant use.

The Use of Pit and Fissure Sealants—A Literature Review

Science.gov (United States)

Naaman, Reem; El-Housseiny, Azza A.; Alamoudi, Najlaa

2017-01-01

This paper reviews the literature and discusses the latest updates on the use of pit and fissure sealants. It demonstrates the effectiveness of pit and fissure sealants in preventing caries and the management of early carious lesions. It compares the use of different sealant materials and their indications. It describes the application technique for sealants. It also reviews the cost-effectiveness of sealants as a preventive strategy. From this review and after the discussion of recently published studies on pit and fissure sealants, it is evident that sealants are effective in caries prevention and in preventing the progression of incipient lesions. It is therefore recommended that pit and fissure sealant be applied to high-caries-risk children for optimum cost-effectiveness. It is a highly sensitive technique that needs optimum isolation, cleaning of the tooth surface, etching, and the application of a thin bonding layer for maximum benefit. Recall and repair, when needed, are important to maximize the effectiveness of such sealant use. PMID:29563440

Influence of remanent magnetization on pitting corrosion in pipeline steel

Energy Technology Data Exchange (ETDEWEB)

Espina-Hernandez, J. H. [ESIME Zacatenco, SEPI Electronica Instituto Politecnico Nacional Mexico, D. F. (Mexico); Caleyo, F.; Hallen, J. M. [DIM-ESIQIE, Instituto Politecnico Nacional Mexico D. F. (Mexico); Lopez-Montenegro, A.; Perez-Baruch, E. [Pemex Exploracion y Produccion, Region Sur Villahermosa, Tabasco (Mexico)

2010-07-01

Statistical studies performed in Mexico indicate that leakage due to external pitting corrosion is the most likely cause of failure of buried pipelines. When pipelines are inspected with the magnetic flux leakage (MFL) technology, which is routinely used, the magnetization level of every part of the pipeline changes as the MFL tool travels through it. Remanent magnetization stays in the pipeline wall after inspection, at levels that may differ from a point to the next. This paper studies the influence of the magnetic field on pitting corrosion. Experiments were carried out on grade 52 steel under a level of remanent magnetization and other laboratory conditions that imitated the conditions of a pipeline after an MLF inspection. Non-magnetized control samples and magnetized samples were subjected to pitting by immersion in a solution containing chlorine and sulfide ions for seven days, and then inspected with optical microscopy. Results show that the magnetic field in the pipeline wall significantly increases pitting corrosion.

New Generation Energy Efficient Refractory Application in Soaking Pits of Bhilai Steel Plant, Sail

Science.gov (United States)

Roy, Indranil; Chintaiah, Perumetla; Bhattacharya, Ajoy Kr.; Garai, Swapan Kr.; Ray Choudhury, Pankaj Kr.; Tiwari, Laksman

In Bhilai Steel Plant (BSP), soaking pits are used for heating ingots for successive rolling into blooms. Pits are operated at a temperature of around 1350°C. Mixed gas (Mixture of Blast Furnace gas & Coke Oven gas) of calorific value around 2040 kcal/Nm3 is used as fuel. The walls of soaking pits were lined with traditional 38% Al2O3 firebricks and top 500mm was cast with 70% Al2O3 low cement castable (LCC). This type of lining results in frequent damages due to hitting by ingots while being lifted from pit by overhead cranes thus affecting the availability of pit. Life of pits was 2 to 2.5 years in BSP with 3-4 cold repairs and 3-4 hot repairs. Energy loss through the wall is also quite high in this type of lining. To triumph over the limitations of the conventional lining, a lining design was developed for the walls which consist of special 70% Al2O3 LCC having high hot strength (HMOR) in combination with specially design flexible SS-304 anchors. Ceramic fiber blanket and insulation bricks were provided between castable and the metallic shell of the pit to minimize the heat loss. A heating schedule was developed and introduced based on available infrastructure at BSP for proper curing of modified LCC based lining. After introduction of modified lining, pit no. 14/2 is running for more than 2.5 years without any repair. To capitalize the success, two more pits i.e. 12/1 and 9/2 were converted to modified lining. These pits are also running satisfactorily for more than 1.5 years. The modification has resulted in higher availability with substantial increase in production. Shell temperature of the modified pits reduced to 90° - 140°C from 120° - 200°C of conventional pits. This shows reduction in heat loss through walls, resulting less fuel consumption and energy saving of about 18%.

Heart rate and core temperature responses of elite pit crews during automobile races.

Science.gov (United States)

Ferguson, David P; Bowen, Robert S; Lightfoot, J Timothy

2011-08-01

There is limited information regarding the physiological and psychological demands of the racing environment, and the subsequent effect on the performance of pit crew athletes. The purpose of this study was to evaluate heart rates (HRs) and core body temperatures (CTs) of pit crew athletes in the race environment. The HR and CT of pit crew athletes (n = 7) and control subjects were measured during 6 National Association for Stock Car Automobile Racing Sprint Cup races using ingestible sensors (HQ Inc, Palmetto, FL, USA). The HR and CT were measured before each race, at 15-minute intervals during the race, and upon completion of each pit stop. Compared to the control subject at each race, the pit crew athletes had significantly (p = 0.014) lower core temperatures (CTs). The pit crew athletes displayed higher HRs on the asphalt tracks than on concrete tracks (p = 0.011), and HR responses of the crew members were significantly (p = 0.012) different between pit crew positions, with the tire changers and jackman exhibiting higher HRs than the tire carriers. Unexpectedly, the CTs of the pit crew athletes were not elevated in the race environment, despite high ambient temperatures and the extensive fire-protection equipment (e.g., helmet, suit, gloves) each pit crew athlete wore. The lack of CT change is possibly the result of the increased HR more efficiently shunting blood to the skin and dissipating heat as a consequence of the athletes' extensive training regimen and ensuing heat acclimation. Additionally, it is possible that psychological stress unique to several of the tracks provided an additive effect resulting in increased heart rates.

Plantar pitted keratolysis: a study from non-risk groups

Directory of Open Access Journals (Sweden)

Asli Feride Kaptanoglu

2012-02-01

Full Text Available Pitted keratolysis is an acquired, superficial bacterial infection of the skin which is characterized by typical malodor and pits in the hyperkeratotic areas of the soles. It is more common in barefooted people in tropical areas, or those who have to wear occlusive shoes, such as soldiers, sailors and athletes. In this study, we evaluated 41 patients who had been diagnosed with plantar pitted keratolysis. The patients were of high socioeconomic status, were office-workers, and most had a university degree. Malodor and plantar hyperhydrosis were the most frequently reported symptoms. The weight-bearing metatarsal parts of the feet were those most affected. Almost half the women in the study gave a history of regular pedicure and foot care in a spa salon. Mean treatment duration was 19 days. All patients were informed about the etiology of the disease, predisposing factors and preventive methods. Recurrences were observed in only 17% of patients during the one year follow-up period. This study emphasizes that even malodorous feet among non-risk city dwellers may be a sign of plantar pitted keratolysis. A study of the real incidence of the disease in a large population-based series is needed.

Effect of nitrite concentration on pit depth in carbon steel exposed to simulated radioactive waste

International Nuclear Information System (INIS)

Zapp, P.E.

1997-01-01

The growth of pits in carbon steel exposed to dilute (0.055 M nitrate-bearing) alkaline salt solutions that simulate radioactive waste was investigated in coupon immersion tests. Most coupons were tested in the as-received condition, with the remainder having been heat treated to produce an oxide film. Nitrite, which is an established pitting inhibitor in these solutions, was present in concentrations from 0 to 0.031 M to 0.16 M; the last concentration is known to prevent pitting initiation in the test solution at the 50 degrees C test temperature. The depths of the deepest pits on coupons of particular exposure conditions were measure microscopically and were analyzed as simple, type 1 extreme value statistical distributions, to predict the deepest expected pit in a radioactive waste tank subject to the test conditions. While the growth rate of pits could not be established from these tests, the absolute value of the deepest pits predicted is of the order of 100 mils after 448 days of exposure. The data indicate that even nitrite concentrations insufficient to prevent pitting have a beneficial effect on limiting the growth of deepest pits

Rationale and concept for a lunar pit reconnaissance probe

Science.gov (United States)

Dorrington, G. E.

2018-04-01

Speculation on near-term scientific reasons for the exploration of lunar pits is offered alongside comments on possible longer-term human exploitation. It is proposed that in order to determine whether or not one or more of the pits offer access the large subsurface voids e.g. a non-collapsed lava tube, a preliminary reconnaissance mission solely focused on obtaining lateral images (and/or LiDAR maps) is needed. Possible concept options for such a preliminary reconnaissance mission are discussed. It is suggested that one of the best possible strategies is to employ a micro-sized probe (∼0.3m) that would hop from a nearby main landing spacecraft to the selected pit. After the surface position of the main lander is determined accurately, the probe would perform a ballistic hop, or hover-traverse, a distance of ∼3 km over the lunar surface using existing propulsive and guidance technology capability. Once hovering above the pit, the probe or a separate tethered imaging unit would then be lowered into the pit to acquire the necessary subsurface void topology data. This data would then be transmitted back to Earth, directly, via the lander, or via a store-and-forward orbiting relay. Preliminary estimates indicate that a probe of ∼14 kg (dry mass) is viable using a conventional hydrazine monopropellant system with a propellant mass fraction of less than ∼0.2 (20%) including margins, suggesting a piggyback architecture would be feasible.

Criticality analysis for weapon disassembly at the Pantex Plant - part I: Bare pits

Energy Technology Data Exchange (ETDEWEB)

Knief, R.A. [Ogden Environmental & Energy Services, Albuquerque, NM (United States)

1997-06-01

This paper briefly describes criticality investigations for weapon assembly and dismantlement at the Pantex Plant. Results are summarized for calculations performed for safety analyses, radiological hazards assessments, and a study to justify the criticality alarm exemption. Pits and pits in containers were modeled in their most reactive configuration. Criticality calculations were performed with the KENO and MCNP code packages. Configurations involving bare pits were subcritical by a substantial amount even with very conservative model assumptions. Thus, it is concluded that a critical configuration involving the bare pits is not credible.

Mud Pit Risk-Based Closure Strategy Report, Nevada Test Site, Nevada, Revision 0

Energy Technology Data Exchange (ETDEWEB)

Brain Hoenes

2004-08-01

This report presents the findings of the human and ecological risk assessment for the NTS mud pits. The risk assessment utilizes data from 52 of the 270 NTS mud pits in conjunction with corroborative data from 87 other DOE mud pits associated with nuclear testing (at locations on the NTS, in the western United States, and Alaska) as well as relevant process knowledge. Based on the risk assessment findings, the report provides a strategy for further evaluation, characterization, and closure of all 270 NTS mud pit CASs using the Streamlined Approach for Environmental Restoration (SAFER).

Embedded system in Arduino platform with Fuzzy control to support the grain aeration decision

Directory of Open Access Journals (Sweden)

Albino Szesz Junior

Full Text Available ABSTRACT: Aeration is currently the most commonly used technique to improve the drying and storage of grain, depending on temperature and water content of the grain, as of the temperature and relative humidity of the outside air. In order to monitor temperature and humidity of the grain mass, it is possible to have a network of sensors in the cells of both internal and external storage. Use of artificial intelligence through Fuzzy theory, has been used since the 60s and enables their application on various forms. Thus, it is observed that the aeration of grain in function of representing a system of controlled environment can be studied in relation to the application of this theory. Therefore, the aim of this paper is to present an embedded Fuzzy control system based on the mathematical model of CRUZ et al. (2002 and applied to the Arduino platform, for decision support in aeration of grain. For this, an embedded Arduino system was developed, which received the environmental values of temperature and humidity to then be processed in a Fuzzy controller and return the output as a recommendation to control the aeration process rationally. Comparing the results obtained from the graph presented by LASSERAN (1981 it was observed that the system is effective.

Mycopopulations of grain and flour of wheat, corn and buckwheat

Directory of Open Access Journals (Sweden)

Plavšić Dragana V.

2017-01-01

Full Text Available According to the nutritive characteristics, whole grain flour is a high quality product, due to its high vitamin, mineral, and dietary fiber content. However, the cereal grains are susceptible to the series of contamination during the ripening, harvesting, processing and storage. The aim of this work was to determine mold presence in grains and flour of wheat, corn and buckwheat. The determination of total number and identification of isolated genera and species of molds were the subject of this research. All samples were contaminated with the molds. The total number of molds per 100 cereal grains was between 60 cfu (wheat and 120 cfu (buckwheat. The total number of molds in the samples of flour ranged from 6.0x101 cfu/g in white wheat flour to 5.0 x102 cfu/g in buckwheat whole grain flour (DG18 medium. Eight fungal genera (Alternaria, Aspergillus, Cladosporium, Chrysonilia, Fusarium, Penicillium, Rhizopus and Scopulariopsis and fifteen species were isolated. The largest number of species of molds was isolated from the genus Aspergillus. About 66.7% of isolated fungi belonged to potentially toxigenic species. The results pointed out the necessity of grain surface treatment, preceding the milling of grains in wheat, corn and whole grain buckwheat flour production.

Situation and development of uranium open-pit mining techniques in China

International Nuclear Information System (INIS)

Li Kaiwen.

1986-01-01

The situation of uranium open-pit mining techniques in China is described. The main experiences in production and management are introduced. Meanwhile the suggestions about the further development of uranium open-pit mining techniques are also proposed

Characterization of etch pits found on a large-grain bulk niobium superconducting radio-frequency resonant cavity

OpenAIRE

Xin Zhao; G. Ciovati; T. R. Bieler

2010-01-01

The performance of superconducting radio-frequency (SRF) resonant cavities made of bulk niobium is limited by nonlinear localized effects. Surface analysis of regions of higher power dissipation is thus of intense interest. Such areas (referred to as “hotspots”) were identified in a large-grain single-cell cavity that had been buffered-chemical polished and dissected for examination by high resolution electron microscopy, electron backscattered diffraction microscopy (EBSD), and optical micro...

Pit disassembly and conversion demonstration environmental assessment and research and development activities

International Nuclear Information System (INIS)

1998-08-01

A significant portion of the surplus plutonium is in the form of pits, a nuclear weapons component. Pits are composed of plutonium which is sealed in a metallic shell. These pits would need to be safely disassembled and permanently converted to an unclassified form that would be suitable for long-term disposition and international inspection. To determine the feasibility of an integrated pit disassembly and conversion system, a Pit Disassembly and Conversion Demonstration is proposed to take place at the Los Alamos National Laboratory (LANL). This demonstration would be done in existing buildings and facilities, and would involve the disassembly of up to 250 pits and conversion of the recovered plutonium to plutonium metal ingots and plutonium dioxide. This demonstration also includes the conversion of up to 80 kilograms of clean plutonium metal to plutonium dioxide because, as part of the disposition process, some surplus plutonium metal may be converted to plutonium dioxide in the same facility as the surplus pits. The equipment to be used for the proposed demonstration addressed in this EA would use some parts of the Advanced Recovery and Integrated Extraction System (ARIES) capability, other existing equipment/capacities, plus new equipment that was developed at other sites. In addition, small-scale R and D activities are currently underway as part of the overall surplus plutonium disposition program. These R and D activities are related to pit disassembly and conversion, MOX fuel fabrication, and immobilization (in glass and ceramic forms). They are described in Section 7.0. On May 16, 1997, the Office of Fissile Materials Disposition (MD) notified potentially affected states and tribes that this EA would be prepared in accordance with NEPA. This EA has been prepared to provide sufficient information for DOE to determine whether a Finding of No Significant Impact (FONSI) is warranted or whether an EIS must be prepared

Mycotoxin occurrence on baled and pit silages collected in Co. Meath

Directory of Open Access Journals (Sweden)

McElhinney C.

2015-12-01

Full Text Available Recent studies of baled silages produced in Ireland have identified considerable filamentous fungal contamination. Many of these fungi are toxigenic, capable of producing secondary metabolites, namely mycotoxins. Mycotoxins are potentially detrimental to livestock health and some can pose a risk to consumers of animal products. Baled (n=20 and pit (n=18 silages from a sample of farms (n=38 in Co. Meath were examined to assess the occurrence of mycotoxins and ascertain whether sampling position within the pit silos (feed face vs. 3 m behind the feed face has an effect on mycotoxin content or other chemical compositional variables. Of the 20 mycotoxins assayed, baled silages contained [mean of positive values (no. of values in mean] mycotoxin concentrations (μg/kg dry matter of beauvericin 36 (2, enniatin (enn. A 9.3 (3, enn. A1 54 (8, enn. B 351 (9, enn. B1 136 (10, mycophenolic acid (MPA 11,157 (8 and roquefortine C (Roq. C 1037 (8 and pit silages contained beauvericin 25 (2 enn. A1 18 (2, enn. B 194 (9, enn. B1 57 (3, MPA 287 (6, Roq. C 3649 (6 and zearalenone 76 (1. There was no difference (P>0.05 observed in the mycotoxin concentrations between baled and pit silages, and 11 of the 20 mycotoxins assayed were below the limits of detection. The position of sampling had no effect on the mycotoxin concentration detected in pit silages. It is concluded that mycotoxin concentrations detected in these pit and baled silages in Co. Meath did not exceed EU regulation or guidance limits, and that similar chemical composition and mycotoxin concentration values occurred at the pit silage feed face and 3 m behind this feed face.

Retrospective Analysis of Mosh-Pit-Related Injuries.

Science.gov (United States)

Milsten, Andrew M; Tennyson, Joseph; Weisberg, Stacy

2017-12-01

Moshing is a violent form of dancing found world-wide at rock concerts, festivals, and electronic dance music events. It involves crowd surfing, shoving, and moving in a circular rotation. Moshing is a source of increased morbidity and mortality. The goal of this study was to report epidemiologic information on patient presentation rate (PPR), transport to hospital rate (TTHR), and injury patterns from patients who participated in mosh-pits. Materials and Methods Subjects were patrons from mosh-pits seeking medical care at a single venue. The events reviewed were two national concert tours which visited this venue during their tour. The eight distinct events studied occurred between 2011 and 2014. Data were collected retrospectively from prehospital patient care reports (PCRs). A single Emergency Medical Service (EMS) provided medical care at this venue. The following information was gathered from each PCR: type of injury, location of injury, treatment received, alcohol or drug use, Advanced Life Support/ALS interventions required, age and gender, disposition, minor or parent issues, as well as type of activity engaged in when injured. Attendance for the eight events ranged from 5,100 to 16,000. Total patient presentations ranged from 50 to 206 per event. Patient presentations per ten thousand (PPTT) ranged from 56 to 130. The TTHR per 10,000 ranged from seven to 20. The mean PPTT was 99 (95% CI, 77-122) and the median was 98. The mean TTHR was 16 (95% CI, 12-29) and the median TTHR was 17. Patients presenting from mosh-pits were more frequently male (57.6%; Psurfing was the next most significant, accounting for 20% of presentations. The most common body part injured was the head (64% of injuries). This retrospective review of mosh-pit-associated injury patterns demonstrates a high rate of injuries and presentations for medical aid at the evaluated events. General moshing was the most commonly associated activity and the head was the most common body part injured

200 West Area Ash Pit Demolition Site closure plan. Revision 1

International Nuclear Information System (INIS)

Ruck, F.R.

1994-01-01

The Ash Pit Demolition Site had two known demolition events, the first occurred in November of 1984, and the second occurred in June of 1986. These demolition events were a form of thermal treatment for discarded explosive chemical products. Because the Ash Pit Demolition Site will no longer be used for this thermal activity, the site will be closed. Closure will be conducted pursuant to the requirements of the Washington State Department of Ecology (Ecology) ''Dangerous Waste Regulations'', Washington Administrative Code (WAC) 173-303-610 and 40 Code of Federal Regulations (CFR) 270.1. The 200 West Area Ash Pit Demolition Site Closure Plan consists of a Part A, Form 3, Dangerous Waste Permit Application (Revision 4) and a closure plan. An explanation of the Part A, Form 3, submitted with this closure plan is provided at the beginning of the Part A Section. The closure plan consists of nine chapters and five appendices. This closure plan presents a description of the Ash,Pit Demolition Site, the history of the waste treated, and the approach that will be followed to close the Ash Pit Demolition Site. Because there were no radioactively contaminated chemicals involved in the demolitions, the information on radionuclides is provided for ''information only''. Remediation of any radioactive contamination is not within the scope of this closure plan. Only dangerous constituents derived from Ash Pit Demolition Site operations will be addressed in this closure plan in accordance with WAC 173-303-610(2)(b)(i)

Structural Design and Monitoring Analysis of Foundation Pit Support in Yiwu Huishang Tiandi

Science.gov (United States)

Zhang, Chunsu

2017-08-01

Huishang Tiandi deep foundation pit in Yiwu is a two-story basement,which is located in the downtown area and adjacent to the city center main traffic trunk. The surrounding environment is too com-plex to slope. The excavation depth is large, the formation is weak and complex, and the groundwater level is high.In order to ensure the safety of the foundation wall and the surrounding environment, the deformation of the foundation pit support is strictly controlled, and the deformation and internal force of the foundation supporting structure and the surrounding building are monitored.The deformation law of the foundation pit is obtained through the analysis of the horizontal displacement, the deformation rate of the supporting struc-ture, the surrounding environment of the foundation pit and the internal force of the anchor cable. The relia-bility and rationality of the design of foundation pit support are verified. It is of reference value for the de-sign and construction of other deep foundation pit engineering in Yiwu area.

Preliminary study of realizability of Karazhyra open pit coal fines briquetting

International Nuclear Information System (INIS)

Deryavko, I.I.; Perepelkin, I.G.; Chuprunov, K.V.

2001-01-01

Main properties of brown coals in Karazhyra open pit upper and lower packs are determined. Characteristics of these coals briquette-ability are evaluated. A conceptual possibility to obtain high-quality briquettes from open pit coal fines is shown. (author)

Viscoelastic response of HTPB based solid fuel to horizontal and vertical storage slumping conditions and it's affect on service life

International Nuclear Information System (INIS)

Nawaz, Q.; Nizam, F.

2011-01-01

Frequent use of solid fuels as thrust generating energy source in modern day space vehicle systems has created a need to assess their serviceability for long term storage under various conditions. Solid fuel grain, the most important part of any solid fuel system, responds visco elastically to any loading condition. For the assessment of the service life of any solid fuel system, the solid fuel grain has to be structurally evaluated in applied storage conditions. Structural integrity of the grain is exceptionally significant to guarantee the successful operation of the solid fuel system. In this work, numerical simulations have been performed to assess the mechanical stresses and strains induced in an HTPB based solid fuel grain during service life employing ABAQUS standard FEA software using 4-node bilinear quadrilateral elements. For finite element analysis (FEA), typical 2-D and p/nth axisymmetric section of 5-point (n) star grain geometry is considered. Mechanical loads include the horizontal or vertical 1-g (solid fuel weight) storage condition. The simulation results are compared with the analytical results for the same grain geometry. Analytically measured slump deflections in grain segment at various storage times have been found in good relation with the FEA based simulation results. This proves the validity of the procedure adopted and is helpful in assessment of the service life of solid fuel systems. (author)

Postharvest quality of GA-treated Florida grapefruit after gamma irradiation with TBZ and storage

International Nuclear Information System (INIS)

Miller, W.R.; McDonald, R.E.

1996-01-01

Grapefruit, Citrus paradisi (Macf.), harvested from gibberellic acid (GA) treated trees were irradiated at 0.3 or 0.6 kGy, and evaluated for quality after treatment and simulated commercial storage. The peel of GA-treated fruit retained green color and the fruit were firmer than control fruit after treatment. A condition, not observed before with grapefruit, was described and termed ‘spongy fruit’, which increased as irradiation dosage increased. The incidence of fruit peel pitting after five weeks' storage increased from < 2% to 11% and 25% as irradiation dose increased from 0 to 0.3 and 0.6 kGy. The majority of pitting at 0.3 kGy was slight and would not have an affect on U.S. #1 Grade for grapefruit. Incidence of decay (mostly green mold) was reduced with thiabendazole (TBZ), and mean decay among all treatments was < 1%. Total soluble solids, titratable acidity and the resulting ratio was not affected by GA or irradiation. There was a general decline in the sensory preference for juice flavor, and pulp flavor and texture as irradiation dose increased. We conclude that GA-treated grapefruit will tolerate irradiation dosage of 0.3 kGy without serious damage; however, at dosage of 0.6 kGy, serious peel damage detrimental to fruit quality will likely develop during storage. (author)

PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS

Science.gov (United States)

Exposed, open pit mine highwalls contribute significantly to the production of acid mine drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

Neutron transport by TRIPOLI-2 code in the lower part of a PWR pit and in the pit-access cell

International Nuclear Information System (INIS)

Vergnaud, T.; Bourdet, L.; Gonnord, J.; Nimal, J.C.; Champion, G.

1984-09-01

The neutrons, which exit the reactor vessel, leak between the reactor vessel and the primary concrete shield and provide high dose rate in the lower part of the reactor pit. In this part of the reactor the biological shield is reduced at the level of the pit-access cell door and of the ventilation duct. Consequently there is a pin-point increase of dose rate at reactor place where access must be free during power operation. Studies concern 900 MWe and 1300 MWe plants; calculation results are compared with dose rate measurements which have been done at several interesting points of reactor. Neutron transport is studied in two steps: - first Monte Carlo calculation carried out by the TRIPOLI-2 system gives the current of neutrons entering into the pit-access cell; - a second calculation is about neutron transport in this cell; it is also performed with the TRIPOLI-2 code which uses a very realistic model for cell geometry. Then the door efficiency is evaluated by a SN one dimension code

Itataia's deposit - Structural zoning of a pit until the level 480 meters

International Nuclear Information System (INIS)

Mendonca, J.C.G.S.

1986-01-01

This work is part of Itataia Project-Geotechnics; in it are introduced several comments concerning the structural zoning of a pit in Itataias' phosphorous-uranipherous deposit, until the level 480 meters. The structural parameters (fractures, faults, foliations) obtained in surface and underground works were statistically treated. Stereographic projection was used to define eventual slipping into the pit. All the data were arranged in tables to make it easy the comparison with experimental pits. (author) [pt

Key technical issues relating to safety of spent fuel dry storage in vaults: CASCAD system

Energy Technology Data Exchange (ETDEWEB)

Berge, F [Societe Generale pour les Techniques Nouvelles (SGN), 78 - Saint-Quentin-en-Yvelines (France)

1994-12-31

The operating CASCAD Facility at the Cadarashe site (FR) was commissioned in May 1990. Fuel is received in tight canisters which are transferred to storage pits in the vault and scheduled to be stored for up to 50 years. Canistering operations are performed in a cell of the reactor building.The paper describes the main functions of the facility as: cask receipt and shipping; fuel unloading; fuel conditioning; canisters emplacements in storage location; fuel storage; fuel retrieving and shipping at the end of the storage period; operation system and operation organization. Safety characteristics of the facility discussed are: fuel decay heat removal; subcriticality control and radiological protection. The fuel decay heat removal has two main purposes: (1) maintaining rod cladding temperature below a set limit in order to keep the fuel in its as received condition; (2) maintaining structures and equipment performing a safety function below the design temperature. The features of the sub-criticality control in the storage vault are such that sub-criticality in normal and accidental conditions is provided by the arrangement of pits in the vault. Radiological protection is based on limiting collective and individual annual dose equivalent to ALARA levels ensuring that they remain in any case below the set limits. Radiological protection system described consists in: confinement of radioactive materials for protection against its dissemination; radiation shielding for protection against irradiation. It is pointed out that all technical solutions presented are based on or adapted from proven technologies used in operating facilities in France or in other countries. The solution not only benefits from the experience of SGN in the design, construction and start-up of facilities for fuel or high level waste handling and storage, but also from the experience of the CEA and COGEMA groups in operating such facilities. 2 figs., 1 ref.

Degradation of bifenthrin and pirimiphos-methyl residues in stored wheat grains (Triticum aestivum L.) by ozonation.

Science.gov (United States)

Savi, Geovana D; Piacentini, Karim C; Bortolotto, Tiago; Scussel, Vildes M

2016-07-15

Pesticide insecticides are used on wheat grains in storage units but their efficiency is hindered by persistent residues in the grains. Therefore, this study aims to evaluate the effectiveness of ozone (O3) gas treatment on the degradation of residual bifenthrin and pirimiphos-methyl insecticides commonly used in storage wheat grains, as well as to evaluate degradation of their by-products. The residues of bifenthrin decreased after 180 min of exposure in a concentration of 60 μmol/mol (a 37.5 ± 7.4% reduction) with 20% moisture content and 0.9 water activity. On the other hand, under the same experimental conditions, the pirimiphos-methyl residues significantly decreased in the wheat grains (71.1 ± 8.6%) after 30 min of exposure. After O3 gas treatment, three by-products of pirimiphos-methyl (m/z=306.1) containing different molecular mass to charge ratios (m/z=278.1, 301.1 and 319.2) were identified by LC-MS. O3 is a strong oxidizer that has shown the potential to reduce pesticide residues in stored grain in order to ensure food quality and safety. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development and characterization of food-grade tracers for the global grain tracing and recall system.

Science.gov (United States)

Lee, Kyung-Min; Armstrong, Paul R; Thomasson, J Alex; Sui, Ruixiu; Casada, Mark; Herrman, Timothy J

2010-10-27

Tracing grain from the farm to its final processing destination as it moves through multiple grain-handling systems, storage bins, and bulk carriers presents numerous challenges to existing record-keeping systems. This study examines the suitability of coded caplets to trace grain, in particular, to evaluate methodology to test tracers' ability to withstand the rigors of a commercial grain handling and storage systems as defined by physical properties using measurement technology commonly applied to assess grain hardness and end-use properties. Three types of tracers to dispense into bulk grains for tracing the grain back to its field of origin were developed using three food-grade substances [processed sugar, pregelatinized starch, and silicified microcrystalline cellulose (SMCC)] as a major component in formulations. Due to a different functionality of formulations, the manufacturing process conditions varied for each tracer type, resulting in unique variations in surface roughness, weight, dimensions, and physical and spectroscopic properties before and after coating. The applied two types of coating [pregelatinized starch and hydroxypropylmethylcellulose (HPMC)] using an aqueous coating system containing appropriate plasticizers showed uniform coverage and clear coating. Coating appeared to act as a barrier against moisture penetration, to protect against mechanical damage of the surface of the tracers, and to improve the mechanical strength of tracers. The results of analysis of variance (ANOVA) tests showed the type of tracer, coating material, conditioning time, and a theoretical weight gain significantly influenced the morphological and physical properties of tracers. Optimization of these factors needs to be pursued to produce desirable tracers with consistent quality and performance when they flow with bulk grains throughout the grain marketing channels.

DEFINICIÓN DE PIT FINAL CAPACITADO BAJO INCERTIDUMBRE

OpenAIRE

PEIRANO OPAZO, FERNANDO ANDRÉS

2011-01-01

El objetivo principal de este trabajo de tesis es desarrollar una metodología y una herramienta que permitan definir un pit final incorporando las restricciones de capacidad y las condiciones de incertidumbre asociadas al recurso geológico. El resultado metodológico consiste en un algoritmo de cálculo que incorpora heurísticas de definición de pit final como es la enunciada por Lerchs y Grossman (1964), en conjunto con heurísticas de secuenciamiento de bloques como son enunciadas por Gersh...

Optimal grade control sampling practice in open-pit mining

DEFF Research Database (Denmark)

Engström, Karin; Esbensen, Kim Harry

2017-01-01

Misclassification of ore grades results in lost revenues, and the need for representative sampling procedures in open pit mining is increasingly important in all mining industries. This study evaluated possible improvements in sampling representativity with the use of Reverse Circulation (RC) drill...... sampling compared to manual Blast Hole (BH) sampling in the Leveäniemi open pit mine, northern Sweden. The variographic experiment results showed that sampling variability was lower for RC than for BH sampling. However, the total costs for RC drill sampling are significantly exceeding current costs...... for manual BH sampling, which needs to be compensated for by other benefits to motivate introduction of RC drilling. The main conclusion is that manual BH sampling can be fit-for-purpose in the studied open pit mine. However, with so many mineral commodities and mining methods in use globally...

Modelling the filling rate of pit latrines | Brouckaert | Water SA

African Journals Online (AJOL)

Excreta (faeces and urine) that are deposited into a pit latrine are subject to biodegradation, which substantially reduces the volume that remains. On the other hand, other matter that is not biodegradable usually finds itsway into pit latrines. The net filling rate is thus dependent on both the rate of addition of material and its ...

241-AY-102 Leak Detection Pit Drain Line Inspection Report

International Nuclear Information System (INIS)

Boomer, Kayle D.; Engeman, Jason K.; Gunter, Jason R.; Joslyn, Cameron C.; Vazquez, Brandon J.; Venetz, Theodore J.; Garfield, John S.

2014-01-01

This document provides a description of the design components, operational approach, and results from the Tank AY-102 leak detection pit drain piping visual inspection. To perform this inspection a custom robotic crawler with a deployment device was designed, built, and operated by IHI Southwest Technologies, Inc. for WRPS to inspect the 6-inch leak detection pit drain line

Criticality safety evaluation report for the 100 KE Basin sandfilter backwash pit

International Nuclear Information System (INIS)

Erickson, D.G.

1995-01-01

This analysis presents the technical basis for establishing a safe mass limit for continued operations of the KE Basin sandfilter backwash pit. The main analysis is based on a very conservative UO 2 -PuO 2 -H 2 O system using the measured isotopic concentrations of uranium and plutonium in the sludge. Appendix C contains analyses of the sandfilter backwash pit utilizing all verified materials presently in the pit, and gives new limits based on assumptions made

Proteomic analysis of the impacts of powdery mildew on wheat grain.

Science.gov (United States)

Li, Jie; Liu, Xinhao; Yang, Xiwen; Li, Yongchun; Wang, Chenyang; He, Dexian

2018-09-30

Powdery mildew of wheat is one of the major foliar diseases, causing significant yield loss and flour quality change. In this study, grain protein and starch response to powdery mildew infection were investigated. Total protein, glutenin and gliadin exhibited a greater increase in grains from infected wheat, while the content of total starch and amylopectin was decreased. Comparative proteomic analysis demonstrated that the overabundant protein synthesis-related proteins might facilitate the accumulation of storage proteins in grains from infected plants. The significant increase in triticin, serpin and HMW-GS in grains from infected wheat might relate to the superior gluten quality. In addition, overabundant carbohydrate metabolism-related proteins in grains from infected wheat were conducive to the depletion of starch, whereas the decreased abundance of ADP glucose pyrophosphorylase might be related to the deficiency of starch synthesis. These results provide a deeper understanding on the change of wheat quality under powdery mildew infection. Copyright © 2018 Elsevier Ltd. All rights reserved.

New diagnostic technology and hidden pits and fissures caries

OpenAIRE

Fabrizio Guerra; Marta Mazur; Francesca Rinaldo; Denise Corridore; Daniele Salvi; Debora Pasqualotto; Gianna Maria Nardi; Livia Ottolenghi

2015-01-01

The accuracy in pits and fissures caries detection is of paramount importance in dental caries primary and secondary prevention. A combination of visual examination and probing is currently the mainstay of occlusal caries diagnosis. Unfortunately, these types of inspection alone may leave a certain number of pit and fissure caries undetected. The Vista Cam iX fluorescence camera (Durr Dental, Bietigheim-Bissingen, Germany) is a novel dental diagnostic tool for quantitative assessment of denta...

78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

Science.gov (United States)

2013-06-05

... chemicals and fumes caused by open burn pits. DATES: Written comments and recommendations on the proposed... to ``OMB Control No. 2900-NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire.... Title: Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire, VA Form 10-10066. OMB...

An Analysis of Hole Trapping at Grain Boundary or Poly-Si Floating-Body MOSFET.

Science.gov (United States)

Jang, Taejin; Baek, Myung-Hyun; Kim, Hyungjin; Park, Byung-Gook

2018-09-01

In this paper, we demonstrate the characteristics of the floating body effect of poly-silicon with grain boundary by SENTAURUS™ TCAD simulation. As drain voltage increases, impact ionization occurs at the drain-channel junction. And these holes created by impact ionization are deposited on the bottom of the body to change the threshold voltage. This feature, the kink effect, is also observed in fully depleted silicon on insulator because grain boundary of the poly-silicon serve as a storage to trap the holes. We simulate the transfer curve depending on the density and position of the grain boundary. The trap density of the grain boundary affects the device characteristics significantly. However similar properties appear except where the grain boundary is located on the drain side.

Final work plan : indoor air and ambient air sampling near the former CCC/USDA grain storage facility in Everest, Kansas.

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, L. M. (Environmental Science Division)

2010-05-24

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at the western edge of Everest, Kansas, from the early 1950s to the early 1970s. Sampling by the Kansas Department of Health and Environment (KDHE) in 1997 resulted in the detection of carbon tetrachloride in one domestic well (the Nigh well) northwest of the former facility. On behalf of the CCC/USDA, Argonne National Laboratory subsequently conducted a series of investigations to characterize the contamination (Argonne 2003, 2006a,b,c). Automatic, continuous monitoring of groundwater levels began in 2002 and is ongoing at six locations. The results have consistently indicated groundwater flow toward the north-northwest from the former CCC/USDA property to the Nigh property, then west-southwest from the Nigh property to the intermittent creek. Sitewide periodic groundwater and surface water sampling with analysis for volatile organic compounds (VOCs) began in 2008. Argonne's combined data indicate no significant downgradient extension of contamination since 2000. At present, the sampling is annual, as approved by the KDHE (2009) in response to a plan developed for the CCC/USDA (Argonne 2009). This document presents a plan for collecting indoor air samples in homes located along and adjacent to the defined extent of the carbon tetrachloride contamination. The plan was requested by the KDHE. Ambient air samples to represent the conditions along this pathway will also be taken. The purpose of the proposed work is to satisfy KDHE requirements and to collect additional data for assessing the risk to human health due to the potential upward migration of carbon tetrachloride and its primary degradation product (chloroform) into homes located in close proximity to the former grain storage facility, as well as along and within 100 ft laterally from the currently defined plume emanating from the former Everest facility. Investigation of the indoor air

Lessons Learned from Pit Viper Integration into Hanford Tank Farm Reality

International Nuclear Information System (INIS)

Catalan, Michael A.; Bailey, Sharon A.; Alzheimer, James M.; Niebuhr, Daniel P.

2002-01-01

The Pit Viper is a tele-operated system intended to enhance worker safety while simultaneously improving the efficiency of pit operations at the Hanford Site. Commercial off-the-shelf (COTS) components were used in an attempt to increase system efficiency. During preparation for initial deployment, the Pit Viper team identified multiple areas where more advanced technology offers substantial improvement in system capabilities. The team also ensured that the system as is, was capable of fulfilling its mission. However, there are valid concerns of the reliability of the technology. Areas where improvement are desired include; operator feedback, manipulator dexterous envelope, and system reliability

Designing local solutions for emptying pit latrines in low-income urban settlements (Malawi)

Science.gov (United States)

Chipeta, W. C.; Holm, R. H.; Kamanula, J. F.; Mtonga, W. E.; de los Reyes, F. L.

2017-08-01

A lack of effective options in local technology poses challenges when onsite household sanitation facilities are eventually filled to capacity in unplanned settlement areas within Mzuzu City, located in northern Malawi. Vacuum trucks currently dominate the market but focus on emptying septic tanks in the more easily accessible planned settlement areas, rather than servicing the pit latrines common in unplanned settlement areas. As a result, households in the unplanned settlement areas within Mzuzu rely primarily on manual pit emptying (i.e., shoveling by hand) or digging a new pit latrine. These practices have associated health risks and are limited by space constraints. This research focused on filling the technological gap through the design, development, and testing of a pedal powered modified Gulper pump using locally available materials and fabrication. A modified pedal powered Gulper technology was developed and demonstrated to be capable of lifting fecal sludge from a depth of 1.5 m with a mean flow rate of 0.00058 m3/s. If the trash content was low, a typical pit latrine with a volume of 1-4 m3 could be emptied within 1-2 h. Based on the findings in our research Phase IV, the pedal powered Gulper modification is promising as a potential emptying technology for lined pit latrines in unplanned settlement areas. The success rate of the technology is about 17% (5 out 30 sampled lined pit latrines were successful) and reflects the difficulty in finding a single technology that can work well in all types of pit latrines with varying contents. We note that cost should not be the only design criteria and acknowledge the challenge of handling trash in pit latrines.

Probability distribution of pitting corrosion depth and rate in underground pipelines: A Monte Carlo study

International Nuclear Information System (INIS)

Caleyo, F.; Velazquez, J.C.; Valor, A.; Hallen, J.M.

2009-01-01

The probability distributions of external-corrosion pit depth and pit growth rate were investigated in underground pipelines using Monte Carlo simulations. The study combines a predictive pit growth model developed by the authors with the observed distributions of the model variables in a range of soils. Depending on the pipeline age, any of the three maximal extreme value distributions, i.e. Weibull, Frechet or Gumbel, can arise as the best fit to the pitting depth and rate data. The Frechet distribution best fits the corrosion data for long exposure periods. This can be explained by considering the long-term stabilization of the diffusion-controlled pit growth. The findings of the study provide reliability analysts with accurate information regarding the stochastic characteristics of the pitting damage in underground pipelines.

Probability distribution of pitting corrosion depth and rate in underground pipelines: A Monte Carlo study

Energy Technology Data Exchange (ETDEWEB)

Caleyo, F. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico)], E-mail: fcaleyo@gmail.com; Velazquez, J.C. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico); Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400, La Habana (Cuba); Hallen, J.M. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico)

2009-09-15

The probability distributions of external-corrosion pit depth and pit growth rate were investigated in underground pipelines using Monte Carlo simulations. The study combines a predictive pit growth model developed by the authors with the observed distributions of the model variables in a range of soils. Depending on the pipeline age, any of the three maximal extreme value distributions, i.e. Weibull, Frechet or Gumbel, can arise as the best fit to the pitting depth and rate data. The Frechet distribution best fits the corrosion data for long exposure periods. This can be explained by considering the long-term stabilization of the diffusion-controlled pit growth. The findings of the study provide reliability analysts with accurate information regarding the stochastic characteristics of the pitting damage in underground pipelines.

3D Modeling of Lacus Mortis Pit Crater with Presumed Interior Tube Structure

Directory of Open Access Journals (Sweden)

Ik-Seon Hong

2015-06-01

Full Text Available When humans explore the Moon, lunar caves will be an ideal base to provide a shelter from the hazards of radiation, meteorite impact, and extreme diurnal temperature differences. In order to ascertain the existence of caves on the Moon, it is best to visit the Moon in person. The Google Lunar X Prize(GLXP competition started recently to attempt lunar exploration missions. Ones of those groups competing, plan to land on a pit of Lacus Mortis and determine the existence of a cave inside this pit. In this pit, there is a ramp from the entrance down to the inside of the pit, which enables a rover to approach the inner region of the pit. In this study, under the assumption of the existence of a cave in this pit, a 3D model was developed based on the optical image data. Since this model simulates the actual terrain, the rendering of the model agrees well with the image data. Furthermore, the 3D printing of this model will enable more rigorous investigations and also could be used to publicize lunar exploration missions with ease.

3D Modeling of Lacus Mortis Pit Crater with Presumed Interior Tube Structure

Science.gov (United States)

Hong, Ik-Seon; Yi, Yu; Yu, Jaehyung; Haruyama, Junichi

2015-06-01

When humans explore the Moon, lunar caves will be an ideal base to provide a shelter from the hazards of radiation, meteorite impact, and extreme diurnal temperature differences. In order to ascertain the existence of caves on the Moon, it is best to visit the Moon in person. The Google Lunar X Prize(GLXP) competition started recently to attempt lunar exploration missions. Ones of those groups competing, plan to land on a pit of Lacus Mortis and determine the existence of a cave inside this pit. In this pit, there is a ramp from the entrance down to the inside of the pit, which enables a rover to approach the inner region of the pit. In this study, under the assumption of the existence of a cave in this pit, a 3D model was developed based on the optical image data. Since this model simulates the actual terrain, the rendering of the model agrees well with the image data. Furthermore, the 3D printing of this model will enable more rigorous investigations and also could be used to publicize lunar exploration missions with ease.