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1

Cómo hacer frente al cáncer  

Cancer.gov

Existen muchos recursos de ayuda y apoyo para las personas con cáncer, sus familiares y amigos. Infórmese sobre las reacciones psicológicas al cáncer y la forma de hacer frente a estas situaciones. Conozca los servicios que ofrecen las comunidades locales y las organizaciones nacionales para ayudarle con los diferentes aspectos del tratamiento y la recuperación del cáncer.

2

Precauciones frente al consumo de huevos  

Center for Food Safety and Applied Nutrition (CFSAN)

Text VersionPage 1. Precauciones frente al consumo de huevos October 2011 Lo que usted debe saber Los ... congelada. October 2011 2 More results from www.fda.gov/downloads/food/foodborneillnesscontaminants

3

Precauciones frente al consumo de huevos  

Center for Food Safety and Applied Nutrition (CFSAN)

Text Version... se puede extender desde el intestino al torrente sanguíneo y luego a otros lugares del cuerpo, lo que puede provocar la muerte, a menos que el ... More results from www.fda.gov/downloads/food/resourcesforyou

4

ENGINEERING ASSESSMENT OF VERMICOMPOSTING MUNICIPAL WASTEWATER SLUDGES  

EPA Science Inventory

Vermicomposting -- the biological degradation of organic matter that occurs as earthworms feed on waste materials -- has been advocated by some as a means of stabilizing and disposing of municipal wastewater sludges. Vermicomposting is being attempted on an experimental scale, th...

5

Transformation of phosphorus during vermicomposting  

Microsoft Academic Search

In view of the growing awareness about vermicomposting technology in recycling a wide range of organic wastes, the behaviour of phosphorus during mineralization of different organic wastes in the absence and presence of epigeic earthworms was studied. The magnitude of the transformation of phosphorus from the organic to inorganic state, and thereby into available forms was found to be considerably

M. Ghosh; G. N. Chattopadhyay; K. Baral

1999-01-01

6

Enriching vermicompost by nitrogen fixing and phosphate solubilizing bacteria  

Microsoft Academic Search

The effect of inoculation of vermicompost with nitrogen-fixing Azotobacter chroococcum strains, Azospirillum lipoferum and the phosphate solubilizing Pseudomonas striata on N and P contents of the vermicompost was assessed. Inoculation of N2 fixing bacteria into vermicompost increased contents of N and P. Enriching vermicompost with rock phosphate improved significantly the available P when inoculated with P. striata. During the incubation

Vivek Kumar; K. P. Singh

2001-01-01

7

Compendium on Solid Waste Management by Vermicomposting.  

National Technical Information Service (NTIS)

Vermicomposting of municipal solid wastes has been attempted only in the last five years and there are presently no full-scale operations. This report assesses the technical and economic feasibility of vermicomposting and is based on several pilot-scale s...

1980-01-01

8

COMPENDIUM ON SOLID WASTE MANAGEMENT BY VERMICOMPOSTING  

EPA Science Inventory

Vermicomposting of municipal solid wastes has been attempted only in the last five years and there are presently no full-scale operations. This report assesses the technical and economic feasibility of vermicomposting and is based on several pilot-scale studies conducted by priva...

9

Vermicompost as a Biological Soil Amendment  

Microsoft Academic Search

\\u000a The viability of using earthworms as a treatment technique for the biological wastes producing organic fertilizers. A variety\\u000a of organic solid wastes, domestic and agro-industrial, can be vermicomposted. Vermicomposting technology involves harnessing\\u000a earthworms as versatile natural bioreactors, which play a vital role in decomposition of organic matter, maintaining soil\\u000a fertility, and bringing out efficient natural recycling and enhanced plants’ growth.

J. Tajbakhsh; E. Mohammadi Goltapeh; Ajit Varma

10

Vermicompost enhances germination of the maritime pine ( Pinus pinaster Ait.)  

Microsoft Academic Search

We investigated the effect of vermicompost on the germination and early development of six different progenies of the maritime\\u000a pine (Pinus pinaster Ait.). We compared the effects of incorporating solid vermicompost into the potting media to those of vermicompost water\\u000a extract. The incorporation of vermicompost in the growing media of maritime pine increased germination by 16%, and particularly,\\u000a addition of

Cristina LazcanoLuis; Luís Sampedro; Rafael Zas; Jorge Domínguez

2010-01-01

11

Effect of pre-composting on vermicomposting of kitchen waste  

Microsoft Academic Search

The aim of this work was to test combination of the thermocomposting and vermicomposting to improve the treatment efficiency and assess the optimum period required in each method to produce good quality compost. The results showed that pre-thermocomposting improved vermicomposting of kitchen waste. A 9-day thermocomposting prior to vermicomposting helped in mass reduction, moisture management and pathogen reduction.

Jaya Nair; Vanja Sekiozoic; Martin Anda

2006-01-01

12

Ammonia emissions during vermicomposting of sheep manure.  

PubMed

The effect of C:N ratio, temperature and water content on ammonia volatilization during two-phase composting of sheep manure was evaluated. The aerobic phase was conducted under field conditions. This was followed by Phase II, vermicomposting, conducted in the laboratory under controlled conditions of water content (70% and 80%) and temperature (15 and 22 °C). The addition of extra straw lead to a 10% reduction in NH3 volatilization compared to sheep manure composted without extra straw. Temperature and water content significantly effected ammonia volatilization at 0 day in Phase II, with a water content of 70% and temperature of 22 °C leading to greater losses of ammonia. Nitrogen loss by ammonia volatilization during vermicomposting ranged from 8% to 15% of the initial N content. The addition of extra straw did not result in significant differences in total carbon content following vermicomposting. PMID:21996478

Velasco-Velasco, Joel; Parkinson, Robert; Kuri, Victor

2011-09-22

13

Stabilization of primary sewage sludge during vermicomposting  

Microsoft Academic Search

In India, over the last few decades, there has been a remarkable increase in sewage sludge production due to population increase and unplanned urbanization. The aim of the present study was to investigate the ability of an epigeic earthworm Eisenia foetida to transform primary sewage sludge (PSS) amended with cow dung (CD) into value added product, i.e., vermicompost in laboratory

Renuka Gupta; V. K. Garg

2008-01-01

14

Vermicomposting of olive oil mill wastewaters.  

PubMed

The disposal of olive oil mill wastewaters (OMW) represents a substantial environmental problem in Italy. A vermicompost process could be an alternative and valid method for the management of OMW. In a laboratory experiment, the OMW were absorbed onto a ligno-cellulosic solid matrix and 30 adult earthworms of Eisenia fetida specie were added. The experiment was carried out for 13 weeks. The number of earthworms increased throughout the experimental period and after 2 weeks about 90% of the earthworms had become sexually mature. The decrease in total organic carbon (about 35%), C : N ratio (from 31.2 to 12.3) and biochemical parameters (hydrolytic enzymes averagely 40% and dehydrogenase 23%), and the increase in humification rate (pyrophosphate extractable carbon (PEC) from 17.6 to 33.3 mg g(-1), and PEC : water-soluble carbon from 1.76 to 2.97) indicated the mineralization and the stabilization of organic matter at the end of the vermicomposting process. At the end of the experiment, the extracellular beta-glucosidase, phosphatase, urease and protease activities, measured in the pyrophosphate extract of the vermicompost, were found to be always higher or equal to that measured at the beginning of the vermicomposting process, suggesting that the enzymes bound to humic matter resisted biological attack and environmental stress. Moreover, the results obtained from the phyto-test showed that the OMW lose their toxicity and stimulate plant germination and growth. PMID:20015937

Macci, Cristina; Masciandaro, Grazia; Ceccanti, Brunello

2009-12-16

15

Vermicomposting of source-separated human faeces for nutrient recycling.  

PubMed

The present study examined the suitability of vermicomposting technology for processing source-separated human faeces. Since the earthworm species Eisenia fetida could not survive in fresh faeces, modification in the physical characteristics of faeces was necessary before earthworms could be introduced to faeces. A preliminary study with six different combinations of faeces, soil and bulking material (vermicompost) in different layers was conducted to find out the best condition for biomass growth and reproduction of earthworms. The results indicated that SVFV combination (soil, vermicompost, faeces and vermicompost - bottom to top layers) was the best for earthworm biomass growth indicating the positive role of soil layer in earthworm biomass growth. Further studies with SVFV and VFV combinations, however, showed that soil layer did not enhance vermicompost production rate. Year-long study conducted with VFV combination to assess the quality and quantity of vermicompost produced showed an average vermicompost production rate of 0.30kg-cast/kg-worm/day. The vermicompost produced was mature as indicated by low dissolved organic carbon (2.4+/-0.43mg/g) and low oxygen uptake rate (0.15+/-0.09mg O(2)/g VS/h). Complete inactivation of total coliforms was noted during the study, which is one of the important objectives of human faeces processing. Results of the study thus indicated the potential of vermicomposting for processing of source-separated human faeces. PMID:19850460

Yadav, Kunwar D; Tare, Vinod; Ahammed, M Mansoor

2009-10-21

16

OPTIMIZATION OF VERMICOMPOST AND WORM-BED LEACHATE FOR THE ORGANIC CULTIVATION OF RADISH  

Microsoft Academic Search

Vermicompost and worm-bed leachate (WBL) are two products obtained from vermicomposting. The objective of this study was to evaluate the effect of different combinations of vermicompost and WBL on cultivating radish (Raphanus sativus L.). A multilevel factorial design with 25 treatments was used to investigate the effect of vermicompost at 0, 10, 20, 30, or 40% and WBL at 0,

Federico Antonio Gutiérrez-Miceli; María Angela Oliva Llaven; Paula Mendoza Nazar; Benigno Ruíz Sesma; José David Álvarez-Solís; Luc Dendooven

2011-01-01

17

Vermicomposting of AgroIndustrial Processing Waste  

Microsoft Academic Search

Agro-industrial wastes- wastes from agriculture, food processing or any cellulose based industries- remain largely unutilized\\u000a and often cause environmental problems like dispersing foul odors, occupying vast areas, ground and surface water pollution\\u000a etc. These wastes could be converted into potential renewable source of energy, if managed sustainably and scientifically.\\u000a In the last few decades, vermicomposting technology has been arising as

V. K. Garg; Renuka Gupta

18

Feasibility of nutrient recovery from industrial sludge by vermicomposting technology  

Microsoft Academic Search

Transformation of industrial sludges into vermicompost is of double interest: on the one hand, a waste is converted into value added product, and, on the other, it controls a pollutant that is a consequence of increasing industrialization. This paper reports the feasibility of utilization of vermicomposting technology for nutrient recovery from industrial sludge in laboratory scale experiment employing Eisenia fetida

Anoop Yadav; V. K. Garg

2009-01-01

19

Vermicomposting of crop residues and cattle dung with Eisenia foetida  

Microsoft Academic Search

We studied vermicomposting with Eisenia foetida of mustard residues and sugarcane trash mixed with cattle dung in a 90-day composting experiment. Vermicomposting resulted in significant reduction in C:N ratio and increase in mineral N, after 90 days of composting, over treatments uninoculated with earthworms. Microbial activity, as measured by dehydrogenase assay, increased up to 60 days and declined on further

Sudha Bansal; K. K Kapoor

2000-01-01

20

Soil agro-ecological management: Fertirrigation and vermicompost treatments  

Microsoft Academic Search

A particular wormcasting (vermicompost from biological sludges) and sewage water (from a municipal sewage plant) have been employed in an ecological strategy for the conservation of arable soils. A soil sampled in the south of Italy (Matera), seeded with Avena sativa was used in experiments on: (1) direct incorporation of vermicompost into the soil (VC treatment) and (2) fertirrigation with

G. Masciandaro; B. Ceccanti; C. Garcia

1997-01-01

21

Vermicomposting of biosolids with cow manure and oat straw  

Microsoft Academic Search

Biosolids, mainly from textile industries and the rest from households, were vermicomposted with Eisenia fetida, cow manure and oat straw for 2 months at three different moisture contents (60%, 70% and 80% dry weight base) in triplicate to reduce pathogens and toxic organic compounds, and to find the best medium for growth of E. fetida. The vermicompost with the best

S. M. Contreras-Ramos; E. M. Escamilla-Silva; L. Dendooven

2005-01-01

22

Chemical changes during vermicomposting of sago industry solid wastes  

Microsoft Academic Search

A laboratory study was undertaken to examine the temporal changes in physico-chemical properties during vermicomposting of sago industry waste. The sago industry waste was blended with cow dung, poultry manure at various proportions, kept for pre-treatment for 21 days and subsequently vermicomposted for a period of 45 days under shade. Earthworm species (Eisenia foetida) was introduced at the rate of

Selvi Subramanian; M. Sivarajan; S. Saravanapriya

2010-01-01

23

Suppression of insect pest populations and damage to plants by vermicomposts  

Microsoft Academic Search

The effects of commercial vermicomposts, produced from food waste, on infestations and damage by aphids, mealy bugs and cabbage white caterpillars were studied in the greenhouse. Vermicomposts were used at substitution rates into a soil-less plant growth medium, MetroMix 360 (MM360), at rates of 100% MM360 and 0% vermicompost, 80% MM360 and 20% vermicompost, and 60% MM360 and 40% vermicompost

Norman Q. Arancon; Paola A. Galvis; Clive A. Edwards

2005-01-01

24

Processing of different types of organic wastes through vermicomposting.  

PubMed

In the present study, an effort has been made to utilize different types of organic wastes, i.e. kitchen waste, agro residue, institutional waste and cow dung through the process of vermicomposting. These organic wastes were collected separately, air dried, grinded and mixed in 4:1 ratio with cow dung (w/w). During the period of vermicomposting (75 days), different physico-chemical parameters were analyzed separately. During this process, pH, organic carbon, organic matter and C:N ratio of different organic waste mixtures showed a declining trend, however, total nitrogen, available phosphorus and exchangeable potassium contents showed increasing trend with the advancement of vermicomposting period. Besides, physico-chemical investigations of these wastes, estimation of earthworm population, biomass and number of cocoon produced during vermicomposting were also analyzed separately. It was found that earthworm population, biomass and cocoon production increased significantly as the duration of vermicomposting process increased upto 75 days. PMID:23029940

Bharadwaj, Alok

2011-07-01

25

Vermicomposting of food waste: assessing the stability and maturity.  

PubMed

The vermicompost using earthworms (Eisenia Fetida) was produced from food waste and chemical parameters (EC, pH, carbon to nitrogen contents (C/N)) and germination bioassay was examined in order to assess the stability and maturity indicators during the vermicomposting process. The seed used in the germination bioassay was cress. The ranges of EC, pH, C/N and germination index were 7.5-4.9 mS/cm, 5.6-7.53, 30.13-14.32% and 12.8-58.4%, respectively. The germination index (GI) value revealed that vermicompost rendered as moderate phytotoxic to cress seed. Pearson correlation coefficient was used to evaluate the relationship between the parameters. High statistically significant correlation coefficient was calculated between the GI value and EC in the vermicompost at the 99% confidence level. The C/N value showed that the vermicompost was stable. As a result of these observations, stability test alone, was not able to ensure high vermicompost quality. Therefore, it appears that determining vermicompost quality requires a simultaneous use of maturity and stability tests. PMID:23369642

Majlessi, Monireh; Eslami, Akbar; Najafi Saleh, Hossein; Mirshafieean, Simin; Babaii, Sara

2012-12-13

26

Vermicomposting of food waste: assessing the stability and maturity  

PubMed Central

The vermicompost using earthworms (Eisenia Fetida) was produced from food waste and chemical parameters (EC, pH, carbon to nitrogen contents (C/N)) and germination bioassay was examined in order to assess the stability and maturity indicators during the vermicomposting process. The seed used in the germination bioassay was cress. The ranges of EC, pH, C/N and germination index were 7.5-4.9 mS/cm, 5.6-7.53, 30.13-14.32% and 12.8-58.4%, respectively. The germination index (GI) value revealed that vermicompost rendered as moderate phytotoxic to cress seed. Pearson correlation coefficient was used to evaluate the relationship between the parameters. High statistically significant correlation coefficient was calculated between the GI value and EC in the vermicompost at the 99% confidence level. The C/N value showed that the vermicompost was stable. As a result of these observations, stability test alone, was not able to ensure high vermicompost quality. Therefore, it appears that determining vermicompost quality requires a simultaneous use of maturity and stability tests.

2012-01-01

27

Qualitative analysis of the stability of a continuous vermicomposting system.  

PubMed

A mathematical model was established to describe ecological relationships in a continuous vermicomposting system. The distributions of organic matter, microbes and earthworms on non-dimensional specific growth rates were simulated. The range of specific growth rates were visualized utilizing three-dimensional reconstruction technology. The stability of a vermicomposting system was not influenced by the initial concentrations of microbes and earthworms, only their species. The coordinates of the stable point depended on the dilution rate and initial amount of organic matter. The method described could be help for establishing a stable continuous vermicomposting system. PMID:23127841

Hu, Enzhu; Liu, Hong

2012-10-10

28

Vermicomposting potential of Perionyx sansibaricus (Perrier) in different waste materials  

Microsoft Academic Search

The decomposition efficiency of Perionyx sansibaricus (Perrier) for vermicomposting was evaluated by using a variety of wastes such as agriculture waste, farm yard manure and urban solid waste. Vermicomposting resulted in significant increase in total N (80.8–142.3%), phosphorous (33.1–114.6%) and potassium (26.3–125.2%), whereas decrease in organic C (14.0–37.0%) as well as C:N ratio (52.4–69.8%) in different experimental beddings. P. sansibaricus

Surendra Suthar

2007-01-01

29

Influence of vermicomposting on solid wastes decomposition kinetics in soils  

Microsoft Academic Search

The effect of vermicomposting on kinetic behavior of the products is not well recognized. An incubation study was conducted\\u000a to investigate C mineralization kinetics of cow manure, sugarcane filter cake and their vermicomposts. Two different soils\\u000a were treated with the four solid wastes at a rate of 0.5 g solid waste C per kg soil with three replications. Soils were

Farshid Nourbakhsh

2007-01-01

30

Worms, Worms, and Even More Worms: A Vermicomposting Guide for Teachers.  

ERIC Educational Resources Information Center

|This guide is designed to help teachers gain a better understanding of how to get a worm vermicomposting system started. It provides reference curricula materials for using worms in the classroom. Chapters include: (1) "Why Worm Vermicomposting;" (2) "Basics of Vermicomposting;" (3) "Worm Facts;" (4) "Classroom Activities;" (5) "Lab Activities;"…

California Integrated Waste Management Board, Sacramento.

31

Comparison of Vermicompost and Composts as Potting Media for Growth of Tomatoes  

Microsoft Academic Search

Vermicomposting and composting are efficient methods for converting solid wastes to useful products. Incorporation of composts and vermicomposts into potting and container media is a potential use for these materials. In a greenhouse trial, effects of a vermicompost produced from raw dairy manure (RDM) along with some other composts produced from tobacco residue (TR), yard leaf (YL), sewage sludge + rice hull

K. Hashemimajd; M. Kalbasi; A. Golchin; H. Shariatmadari

2004-01-01

32

Growth of bedding plants in commercial potting substrate amended with vermicompost  

Microsoft Academic Search

Vermicompost has been promoted as a viable alternative container media component for the horticulture industry. The purpose of this research was to investigate the use of vermicompost at different points in the production cycle of tomato, marigold, pepper, and cornflower. The incorporation of vermicompost of pig manure origin into germination media up to 20% v\\/v enhanced shoot and root weight,

G. R. Bachman; J. D. Metzger

2008-01-01

33

VERMICOMPOSTING AS A NITROGEN SOURCE IN GERMINATING KIDNEY BEAN IN TRAYS  

Microsoft Academic Search

This study assessed the effectiveness of vermicompost as a germination media and nitrogen source for kidney bean Phaseolus vulgaris L. Five treatments were tested, based on the addition of increasing quantities of barren soil to vermicompost, and irrigated with four treatments of increasing urea-water solution. Chemical analysis of the different mixtures of vermicompost and barren soil were made. Percentage germination,

G. Rodríguez-Quiroz; W. Valenzuela-Quiñónez; E. Nava-Pérez

2011-01-01

34

Precauciones frente al consumo de huevos  

Center for Food Safety and Applied Nutrition (CFSAN)

... La mayoría de las personas infectadas por Salmonella comienza a manifestar diarrea, fiebre, dolores abdominales y vómito entre 12 y 72 horas ... More results from www.fda.gov/food/foodborneillnesscontaminants/buystoreservesafefood

35

Management of food industry waste employing vermicomposting technology.  

PubMed

This paper reports the vermicomposting of food industry sludges (FIS) mixed with different organic wastes employing Eisenia fetida. A total of 10 vermicomposting units containing different wastes combinations were established. After 15 weeks significant increase in total nitrogen (N(total)) (60-214%), total available phosphorous (P(avail)) (35.8-69.6%), total sodium (Na(total)) (39-95%), and total potassium (K(total)) (43.7-74.1%), while decrease in pH (8.45-19.7%), total organic carbon (OC(total)) (28.4-36.1%) and C:N ratio (61.2-77.8%) was recorded. The results indicated that FIS may be converted into good quality manure by vermicomposting if spiked with other organic wastes in appropriate quantities. PMID:22197330

Garg, V K; Suthar, S; Yadav, Anoop

2011-12-03

36

Metal transfer in vermicomposting of sewage sludge and plant wastes  

SciTech Connect

Sewage sludge is an urban waste that has a potential nutrient value for recycling into food production. A set of guidelines has been developed that prescribes the quality of sludge suitable for utilization on foodlands. A number of sewage sludges do not meet the criteria and are therefore not acceptable for direct foodland application. One of the options available for such sludges is the production of compost and one of these composting processes involves worms (vermicomposting). This study looks at a pilot vermicomposting operation and follows metal concentrations by batch lot from the sewage sludge to the final commercial product.

Frank, R. (Univ. of Guelph, Ontario); Klauck, C.; Stonefield, K.I.

1983-12-01

37

Chemical changes during vermicomposting of sago industry solid wastes.  

PubMed

A laboratory study was undertaken to examine the temporal changes in physico-chemical properties during vermicomposting of sago industry waste. The sago industry waste was blended with cow dung, poultry manure at various proportions, kept for pre-treatment for 21 days and subsequently vermicomposted for a period of 45 days under shade. Earthworm species (Eisenia foetida) was introduced at the rate of 50 g/kg of waste. The substrate moisture content and temperature were monitored regularly. The vermicomposts were sampled at 0, 15, 30 and 45 days for the assessment of temporal changes in physico-chemical properties. The data revealed vermicomposting of sago wastes, cow dung and poultry manure mixed at equal proportion (1:1:1) produced a superior quality manure with desirable C:N ratio and higher nutritional status than composting. E. foetida is an earthworm suitable for composting organic wastes such as poultry manure with extreme pH and high temperature and sago waste with high organic carbon in a shorter period of time. This study suggests that the sago industry solid waste could be effectively converted into highly valuable manure that can be exploited to promote crop production. PMID:20359816

Subramanian, Selvi; Sivarajan, M; Saravanapriya, S

2010-03-09

38

Isolation and identification of fungal communities in compost and vermicompost  

Microsoft Academic Search

This research illustrates the qualitative and quantitative composition of the mycoflora of both a green compost (thermophilically produced from plant debris) and a vermicompost (mesophili- cally produced by the action of earthworms on plant and animal wastes after thermophilic precondition- ing). Fungi were isolated using three media (PDA, CMC, PDA plus cycloheximide), incubated at three temperatures (24, 37 and 45

Antonella Anastasi; G. C. Varese; V. Filipello Marchisio

2005-01-01

39

Vermicomposting of sewage sludge: a new technology for Mexico  

Microsoft Academic Search

In Mexico 31% of the treatment plants have a flow less than 60 l\\/s. This study offers a simple and economical alternative through vermicomposting to resolve the management of sewage sludge and water hyacinth for these small treatment plants. This study was developed with laboratory and pilot scale systems. In the laboratory Eisenia foetida survival was quantified. They were fed

L. Cardosa Vigueros; E. Ramírez Camperos

40

Vermicompost extracts influence growth, mineral nutrients, phytonutrients and antioxidant activity in pak choi ( Brassica rapa cv. Bonsai, Chinensis group) grown under vermicompost and chemical fertiliser  

Microsoft Academic Search

BACKGROUND: Multiple studies have been reported on the effect of compost tea on suppression of certain plant diseases. However, relatively little work has been done to investigate the effect of vermicompost tea on yield and nutritional quality of vegetable crops. In this study, experiments were conducted to determine the effect of extraction method on vermicompost tea quality and subsequent effects

Archana P Pant; Theodore JK Radovich; Ngyuen V Hue; Stephen T Talcott; Kristen A Krenek

2009-01-01

41

Waste recycling: utilization of coffee grounds and kitchen waste in vermicomposting.  

PubMed

Vermicomposting using Lumbricus rubellus for 49 days was conducted after 21 days of pre-composting. Three different combination of treatments were prepared with eight replicates for each treatment namely cow dung: kitchen waste in 30:70 ratio (T(1)), cow dung: coffee grounds in 30:70 ratio (T(2)), and cow dung: kitchen waste: coffee grounds in 30:35:35 ratio (T(3)). The multiplication of earthworms in terms of numbers and weight were measured at the end of vermicomposting. Consequently, only T(2) showed significant increase (from it initial stage) compared to other treatments. The presence of coffee grounds in T(2) and T(3) showed higher percentage of nutrient elements in vermicompost produced. The data reveal that coffee grounds can be decomposed through vermicomposting and help to enhance the quality of vermicompost produced rather than sole use of kitchen waste in vermicomposting. PMID:18752936

Adi, A J; Noor, Z M

2008-08-26

42

Vermicomposting of distillation waste of citronella plant (Cymbopogon winterianus Jowitt.) employing Eudrilus eugeniae.  

PubMed

Laboratory experiment on vermicomposting of distillation waste of java citronella (Cymbopogon winterianus Jowitt.) was carried out employing Eudrilus eugeniae, in two seasonal trials, covering summer and winter periods. Two vermicomposting treatments were conducted in earthen pots, one with citronella plant waste only (CW) and the other, a mixture of citronella waste and cowdung in the proportion 5:1 (CW+CD). Vermicomposting of citronella waste resulted reduction in C/N ratio (83.5-87.7%), enhancement of ash content and a number of macro and micronutrients. The FT-IR spectroscopy of the vermicompost revealed the reduction in aliphatic and aromatic compound as well as increase in amide group after the 105 days stabilization process. The vermicompost output was significantly enhanced in CW+CD treatment than CW treatment. Even, nutrient content of the vermicompost was also higher in CW+CD treatment than CW alone indicating the positive role of cowdung in improvement of quantity and quality. PMID:21550233

Deka, H; Deka, S; Baruah, C K; Das, J; Hoque, S; Sarma, N S

2011-04-20

43

Fruit Characteristics of Bell Pepper Cultivated in Sheep Manure Vermicompost Substituted Soil  

Microsoft Academic Search

The effects of earthworm-processed sheep manure (vermicompost) on growth, productivity, and characteristics of bell pepper fruits (Capsicum annum) (cv ‘Ancho supremo’) were investigated in a greenhouse experiment. Six treatments were applied combining vermicompost and soil in 0:1, 1:1, 1:2, 1:3, 1:4, and 1:5 (v\\/v) ratios. Plant characteristics were measured 21 and 90 days after transplanting. Addition of vermicompost increased plant

María Angela Oliva Llaven; Jose Luis Guzman Jimenez; Blanca Irene Cabrera Coro; Reiner Rincón-Rosales; Joaquín Montes Molina; Luc Dendooven; Federico A. Gutiérrez-Miceli

2008-01-01

44

Bioconversion of herbal industry waste into vermicompost using an epigeic earthworm Eudrilus eugeniae.  

PubMed

The aim of the present study was to investigate the potential of bioconversion of industrial herbal waste to vermicompost using Eudrilus eugeniae. Vermibeds were made using a mixture of herbal waste and cowdung (1?:?1) in comparison with the use of cowdung alone as substrate, resulting in vermicomposts 1 and 2, respectively. Different parameters were studied and it was observed that the nutrient profile of vermicompost 1 strongly influenced the growth of pea (Pisum sativum) and marigold plant (Tagetus erectus). The dry and fresh weight of shoots and roots, number of flowers, total yield in terms of fruit showed significant increase with vermicompost 1. Furthermore, vermicompost 1 (herbal waste and cow dung as substrate) resulted in a significant reduction in TOC by 58% in comparison with vermicompost 2 (cowdung as substrate). The C?:?N ratio was less than 20 in vermicompost 1 as well as in vermicompost 2, which indicated an advanced degree of stabilization and mineralization. The ability of earthworms to survive, grow and breed in the vermibed fed with the herbal waste indicates the sustainability and efficiency of a heterogeneous kind of organic waste. The results of the study suggested that bulk industrial herbal waste can be utilized as a substrate for vermicomposting and this can be proposed as an alternative for waste disposal in a clean green manner, promoting the concept of organic farming. PMID:20952444

Kumari, Mamta; Kumar, Sudhir; Chauhan, Rajinder Singh; Ravikanth, K

2010-10-15

45

REMOVAL OF Cu, Cr, Ni, Zn, AND Cd FROM ELECTROPLATING WASTES AND SYNTHETIC SOLUTIONS BY VERMICOMPOST OF CATTLE MANURE  

Microsoft Academic Search

This study was undertaken to evaluate the retention of Cu, Cr, Ni, Zn, and Cd under laboratory conditions from synthetic solution and electroplating wastes by vermicompost. A glass column was loaded with vermicompost, and metal solutions were passed through it. Metal concentrations were then measured in the eluate in order to evaluate the amounts retained by the vermicompost. Measurements of

Cláudio Pereira Jordão; Madson de Godoi Pereira; Rosilene Einloft; Marlete Bastos Santana; Carlos Roberto Bellato; Jaime Wilson Vargas de Mello

2002-01-01

46

EFFECT OF VERMICOMPOSTED COIRPITH ON THE GROWTH OF ANDROGRAPHIS PANICULATA  

Microsoft Academic Search

An exotic earthworm, Eudrilus eugeniae (Kinberg), was used to prepare coirpith based compost. This vermicomposted coirpith was amended with alkaline soil from an industrial site and compared with coirpith composted with EM (effective microorganisms) as a growth medium for the medicinal plant, Andrographis paniculata (Burm.f.) wall.ex.Nees, in field plots. Significant plant growth was attained when the same compost was amended

Vijaya D; Padmadevi S. N; Chellapandi P

47

The treatment of domestic wastewater using small-scale vermicompost filter beds  

Microsoft Academic Search

The aim of this study is to quantify the effect of filter bed depth and solid waste inputs on the performance of small-scale vermicompost filter beds that treat the soluble contaminants within domestic wastewater. The study also aims to identify environmental conditions within the filters by quantifying the oxygen content and pH of wastewater held within it. Vermicompost is being

M Taylor; W. P Clarke; P. F Greenfield

2003-01-01

48

Feasibility of utilization of horse dung spiked filter cake in vermicomposters using exotic earthworm Eisenia foetida  

Microsoft Academic Search

This contribution reports the potential of vermicomposting technology in the management of horse dung (HD) spiked sugar mill filter cake (SMFC) using an epigeic earthworm Eisenia foetida under laboratory conditions. A total of six vermicomposters filled with different ratios of HD and SMFC were maintained for this study. The growth and fecundity of E. foetida was monitored for 12 weeks.

Pritam Sangwan; C. P. Kaushik; V. K. Garg

2008-01-01

49

Hydrolytic enzyme activities of extracted humic substances during the vermicomposting of a lignocellulosic olive waste  

Microsoft Academic Search

Humic substances and three hydrolytic enzymes (?-glucosidase, phosphatase and urease) were extracted by neutral sodium pyrophosphate from an olive waste (dry olive cake), alone or mixed with municipal biosolids, during a nine month vermicomposting process. Easily degradable compounds decreased during the vermicomposting process because of microbial consumption. When municipal biosolids were added to dry olive cake, microbial activity increased and

E. Benitez; H. Sainz; R. Nogales

2005-01-01

50

Vermicomposting of mixed solid textile mill sludge and cow dung with the epigeic earthworm Eisenia foetida  

Microsoft Academic Search

This paper reports the results of a study of vermicomposting with Eisenia foetida of solid textile mill sludge mixed with cow dung in different ratios in a 90 days composting experiment. Vermicomposting resulted in significant reduction in C:N ratio and increase in TKN. Total K and Ca were lower in the final cast than the initial feed mixture. Microbial activity

Priya Kaushik; V. K. Garg

2003-01-01

51

Vermicompost Effects on the Growth and Flowering of Petunia hybrida 'Dream Neon Rose  

Microsoft Academic Search

The effects of vermicompost of an animal manure origin on the growth and flowering of Petunia hybrida 'Dream Neon Rose' grown under glasshouse conditions were determined. Petunia seeds were germinated, transplanted into media and grown-on for 150 days. The traditional base medium (control) was a mix ture of 70% farm soil and 30% sand (v\\/v). Treatments were either vermicompost incorporated

E. Chamani; D. C. Joyce; A. Reihanytabar

2008-01-01

52

Mechanism of metribuzin herbicide sorption by humic acid samples from peat and vermicompost  

Microsoft Academic Search

Humic acids (one derived from vermicompost, originating from animal manure and treated with the earthworm Eisenia foetida or Lumbricus rubellus, and the other originating from peat) were characterized in respect of their major elemental UV-Vis spectroscopy and acidity. Humic acid, isolated from vermicompost (VHA), was compared with the humic acid sample extracted from peat (PHA) in respect of its chemical

Maria Diva Landgraf; Sebastião Claudino da Silva; Maria Ol??mpia de O. Rezende

1998-01-01

53

Bioconversion of wastes from olive oil industries by vermicomposting process using the epigeic earthworm Eisenia andrei  

Microsoft Academic Search

The present work evaluates the possible bioconversion of wet olive cake by low-cost biostabilization (vermicomposting process). Wet olive cake fresh (WOC), precomposted (WOCP), or mixed with biosolids (WOCB), were vermicomposted for 6 months to obtain organic amendments for agricultural and remediation purposes. The results showed initial differences depending on previous treatment. WOCP was initially more stable, presented a low C:N

Raquel Melgar; Emilio Benitez; Rogelio Nogales

2009-01-01

54

Formulation of a liquid fertilizer for sorghum ( Sorghum bicolor (L.) Moench) using vermicompost leachate  

Microsoft Academic Search

Leachate from vermicomposting contains large amounts of plant nutrients and can be used as liquid fertilizer, but normally diluted to avoid plant damage. The amount of nutrients applied is thus reduced so that an additional fertilizer is required. We investigated how dilution of vermicompost leachate combined with different concentrations of NPK triple 17 fertilizer, and polyoxyethylene tridecyl alcohol as dispersant

Federico Antonio Gutiérrez-Miceli; Roberto Carlos García-Gómez; Reiner Rincón Rosales; Miguel Abud-Archila; Oliva Llaven María Angela; Marcos Joaquín Guillen Cruz; Luc Dendooven

2008-01-01

55

Volume of Vermicompost-Based Potting Mix for Vegetable Transplants Determined Using Fuzzy Biomass Growth Index  

Microsoft Academic Search

Good quality transplants are necessary so that plants will survive and produce at acceptable levels. The efficacy of vermicompost for vegetable transplant development needs to be clarified. An investigation was conducted to identify the mix and volume of vermicompost-based potting mixes required for production of good quality transplants of tomato (Solanum lycopersicum L.), eggplant (S. melongena L.), and chili pepper

G. V. Prasanna Kumar; H. Raheman

2010-01-01

56

Effects of stocking density and feeding rate on vermicomposting of biosolids  

Microsoft Academic Search

The double-pronged problem of quantity, and disposal of waste streams from a myriad of industries, is becoming increasingly acute, the world over. The use of earthworms as a waste treatment technique for such wastes is gaining popularity. This method is commonly known as vermicomposting. Compared to conventional microbial composting, vermicomposting produces a product that is more or less homogenous, with

P. M' Ndegwa; S. A. Thompson; K. C Das

2000-01-01

57

Dynamics of vermicomposting of solid textile mill sludge spiked with various organic wastes  

Microsoft Academic Search

In our laboratory the work is in progress to demonstrate the management of solid textile mill sludge (STMS) by vermicomposting. The laboratory based experiments have been conducted on vermicomposting of STMS spiked with cow dung (CD), biogas plant slurry (BPS), poultry droppings (PD) and agricultural residues. The results showed that Eisenia foetida did not survive in fresh STMS. The maximum

V. K. Garg; Priya Kaushik

58

Feasibility of vermicomposting for vegetable greenhouse waste recycling.  

PubMed

This study was conducted in order to evaluate the feasibility of Eisenia andrei for vermicomposting heterogeneous-plant (HP), tomato-plant (P), and damaged tomato-fruit (T) greenhouse vegetable wastes. Earthworm growth and reproduction were monitored over a 12-week period, and variations in chemical parameters, enzyme activity, phytotoxicity test, and genetic fingerprinting of bacterial communities were evaluated. While high rates of salinity prevented earthworm survival in HP and P (>10 dS m(-1)), T was vermicomposted recording an adequate earthworm growth and cocoon production. The latter waste was successfully stabilized, as indicated by the significant decrease in its TOC content ( approximately 13-26%) and C:N ratio ( approximately 16-36%) and its high germination indices ( approximately 39-72%). The similar enzyme activities levels and bacterial community fingerprintings recorded in diverse vermicomposts obtained from T waste indicate that this type of waste favoured the existence of analogous bacterial communities responsible for the high degree of stabilization and maturity detected. PMID:20727739

Fernández-Gómez, Manuel J; Romero, Esperanza; Nogales, Rogelio

2010-08-01

59

Influence of vermicomposting on solid wastes decomposition kinetics in soils*  

PubMed Central

The effect of vermicomposting on kinetic behavior of the products is not well recognized. An incubation study was conducted to investigate C mineralization kinetics of cow manure, sugarcane filter cake and their vermicomposts. Two different soils were treated with the four solid wastes at a rate of 0.5 g solid waste C per kg soil with three replications. Soils were incubated for 56 d. The CO2-C respired was monitored periodically and a first-order kinetic model was used to calculate the kinetic parameters of C mineralization. Results indicated that the percentage of C mineralized during the incubation period ranged from 31.9% to 41.8% and 55.9% to 73.4% in the calcareous and acidic soils, respectively. The potentially mineralizable C (C 0) of the treated soils was lower in the solid waste composts compared to their starting materials. Overall, it can be concluded that decomposable fraction of solid wastes has decreased due to vermicomposting.

Nourbakhsh, Farshid

2007-01-01

60

Microbial diversity of vermicompost bacteria that exhibit useful agricultural traits and waste management potential.  

PubMed

Vermicomposting is a non-thermophilic, boioxidative process that involves earthworms and associated microbes. This biological organic waste decomposition process yields the biofertilizer namely the vermicompost. Vermicompost is a finely divided, peat like material with high porosity, good aeration, drainage, water holding capacity, microbial activity, excellent nutrient status and buffering capacity thereby resulting the required physiochemical characters congenial for soil fertility and plant growth. Vermicompost enhances soil biodiversity by promoting the beneficial microbes which inturn enhances plant growth directly by production of plant growth-regulating hormones and enzymes and indirectly by controlling plant pathogens, nematodes and other pests, thereby enhancing plant health and minimizing the yield loss. Due to its innate biological, biochemical and physiochemical properties, vermicompost may be used to promote sustainable agriculture and also for the safe management of agricultural, industrial, domestic and hospital wastes which may otherwise pose serious threat to life and environment. PMID:23961356

Pathma, Jayakumar; Sakthivel, Natarajan

2012-10-04

61

Optimizing vermistabilization of waste activated sludge using vermicompost as bulking material.  

PubMed

An integrated composting-vermicomposting system has been developed for stabilization of waste activated sludge (WAS) using matured vermicompost as bulking material and Eisenia fetida as earthworm species. Composting was considered as the main processing unit and vermicomposting as polishing unit. The integrated system was optimized by successive recycling and mixing of bulking material with WAS during composting and examining the effects of environmental condition (i.e. temperature: 10-30°C and relative humidity: 50 and 90%) and stocking density (0-5 kg/m(2)) on vermicomposting. The composting stage resulted in sufficient enrichment of bulking material with organic matter after 20 cycles of recycling and mixing with WAS and produced materials acceptable for vermicomposting. Vermicomposting of composted material caused significant reduction in pH, volatile solids (VS), specific oxygen uptake rate (SOUR), total carbon (TC), total organic carbon (TOC), C/N ratio and pathogens and a substantial increase in electrical conductivity (EC), total nitrogen (TN) and total phosphorous (TP). The environmental conditions (i.e. temperature: 10-30°C and relative humidity: 50 and 90%) and stocking density (0-5 kg/m(2)) have profound effects on vermicomposting. Temperature of 20°C with high humidity is the best suited environmental condition for vermicomposting employing E. fetida. The favorable stocking density range for vermiculture is 0.5-2.0 kg/m(2) (optimum: 0.5 kg/m(2)) and for vermicomposting is 2.0-4.0 kg/m(2) (optimum: 3.0 kg/m(2)), respectively. The integrated composting-vermicomposting system potentially stabilizes and converts the hazardous WAS into quality organic manure for agronomic applications without any adverse effects. PMID:21145224

Hait, Subrata; Tare, Vinod

2010-12-08

62

Vermicomposting of source-separated human faeces by Eisenia fetida: effect of stocking density on feed consumption rate, growth characteristics and vermicompost production.  

PubMed

The main objective of the present study was to determine the optimum stocking density for feed consumption rate, biomass growth and reproduction of earthworm Eisenia fetida as well as determining and characterising vermicompost quantity and product, respectively, during vermicomposting of source-separated human faeces. For this, a number of experiments spanning up to 3 months were conducted using soil and vermicompost as support materials. Stocking density in the range of 0.25-5.00 kg/m(2) was employed in different tests. The results showed that 0.40-0.45 kg-feed/kg-worm/day was the maximum feed consumption rate by E. fetida in human faeces. The optimum stocking densities were 3.00 kg/m(2) for bioconversion of human faeces to vermicompost, and 0.50 kg/m(2) for earthworm biomass growth and reproduction. PMID:21377345

Yadav, Kunwar D; Tare, Vinod; Ahammed, M Mansoor

2011-03-04

63

Changes in labile phosphorus forms during maturation of vermicompost enriched with phosphorus-solubilizing and diazotrophic bacteria.  

PubMed

The aim of this study was to assess the effect of N(2)-fixing and P-solubilizing bacteria during maturation of vermicompost on phosphorus availability. A bacterial suspension containing Burkholderia silvatlantica, Burkholderia spp. and Herbaspirillum seropedicae was applied at the initial stage of vermicomposting. At the end of the incubation time (120days), the nitrogen content had increased by18% compared to uninoculated vermicompost. Water-soluble P was 106% higher in inoculated vermicompost while resin-extractable P increased during the initial vermicomposting stage and was 21% higher at 60days, but was the same in inoculated and uninoculated mature compost. The activity of acid phosphatase was 43% higher in inoculated than uninoculated vermicompost. These data suggest that the introduction of the mixed culture had beneficial effects on vermicompost maturation. PMID:22342081

Busato, Jader G; Lima, Lívia S; Aguiar, Natália O; Canellas, Luciano P; Olivares, Fábio L

2012-01-31

64

Comparative assessment in enzyme activities and microbial populations during normal and vermicomposting.  

PubMed

Changes in extracellular enzyme activities and microbial populations were studied during the normal composting and vermicomposting of fruitpulp, vegetable waste, groundnut husk and cowdung. The microbial numbers and their extracellular enzyme profiles showed relative variation and were found increasingly more abundant in vermicompost than in normal compost leading to the conversion of agricultural waste into value added product. In vermicompost, the maximum enzyme activities (cellulase, amylase, invertase, protease and urease) were observed during 21-35 days. The cellulase, amylase and protease activities of vermicompost reached the maximum values by 28th day of 1175, 825 microg reducing sugar g(-1) hr(-1) and 28 micro mol of aminoacid g(-1) hr(-1) of vermicompost samples respectively. Similarly the invertase and urease activities reached to peak values of 876 microg reducing sugar g(-1) hr(-1) and 197 microg NH4(+)-N g(-1) ha(-1) sample on 35th day respectively. Most of the enzymes showed correlation with change in number and types of different microbial groups like bacteria, fungi and actinomycetes during vermicomposting with maximum number of 126 x 10(6), 28 x 10(4) and 93 x 10(5) CFU g(-1) sample respectively. In contrast delayed greatest enzyme activities were observed on 42-49th day i.e., last days of normal composting. Earthworms stimulated biochemical activity and nutrient cycling by 40-45% contributing to the reduction of period of degradation of agricultural wastes resulting in maturation of vermicompost by 28th day. PMID:20329398

Devi, S Haritha; Vijayalakshmi, K; Jyotsna, K Pavana; Shaheen, S K; Jyothi, K; Rani, M Surekha

2009-11-01

65

Effects of a precomposting step on the vermicomposting of dairy manure-waste paper mixtures.  

PubMed

Thermophilic composting is being promoted as a means of sanitizing waste materials prior to vermicomposting. The precomposting duration is, however, critical to the success of the vermicomposting phase as it affects worm biomass. This study evaluated the effectiveness of different precomposting periods (0, 1, 2, 3 and 4 weeks) on the sanitization and vermicomposting of dairy manure-waste paper mixtures. The parameters measured were coliform bacteria and protozoa oocyst numbers, earthworm growth, as well as stabilization and nutrient content of vermicomposts. Over 95% of fecal coliforms, Escherichia coli and of E. coli 0157 were eliminated from the waste materials within 1 week of precomposting and total elimination of these and protozoan oocysts was achieved after 3 weeks of precomposting. Microbial biomass carbon and water soluble carbon of waste mixtures decreased with increase in precomposting time and impacted negatively on earthworm growth and subsequent stabilization of the dairy manure-paper waste mixtures. Vermicomposts from waste mixtures precomposted for over 2 weeks were less stabilized, less humified and had lower nutrient contents than vermicomposts from waste mixtures precomposted for 1 week or less. A precomposting period of 1 week was found to be ideal for the effective vermicomposting of dairy manure-waste paper mixtures. PMID:20421247

Mupondi, Lushian T; Mnkeni, Pearson N S; Muchaonyerwa, Pardon

2010-04-26

66

Pilot-scale vermicomposting of pineapple wastes with earthworms native to Accra, Ghana.  

PubMed

Pineapple wastes, an abundant organic waste in Accra, Ghana, were vermicomposted using native earthworms (Eudrilus eugeniae Kinberg) collected from the banks of streams and around bath houses of this city. Triplicate pilot-scale vermidigesters containing about 90 earthworms and three other control boxes with no earthworms were fed pineapple pulp or peels, and the loss of wet mass was monitored over 20 weeks. In a second experiment, a 1:1 mixture of pineapple peels and pulp (w/w) was fed to triplicate pilot-scale vermicomposters and control boxes during a 20 week period. One month after feeding ended, the vermicompost and composted (control) waste was air dried and analyzed. During the first experiment, the vermicomposted pineapple pulp and peels lost 99% and 87% of their wet mass, respectively, indicating the potential for vermicomposting. Fresh pineapple waste exhibited an initial pH of 4.4, but after 24 weeks, the vermicompost and compost had acquired a neutral to alkaline pH of 7.2-9.2. The vermicompost contained as much as 0.4% total N, 0.4% total P and 0.9% total K, and had a C:N ratio of 9-10. A reduction of 31-70% in the Escherichia coli plus Salmonella loads and 78-88% in the Aspergillus load was observed during vermicomposting. The rapid breakdown of pineapple wastes by E. eugeniae demonstrated the viability of vermicomposting as a simple and low cost technology recycling this waste into a soil amendment that could be used by the 2500 vegetable producers of Accra and its surrounding areas. PMID:19620003

Mainoo, Nana O K; Barrington, Suzelle; Whalen, Joann K; Sampedro, Luis

2009-07-19

67

Role of vermicompost chemical composition, microbial functional diversity, and fungal community structure in their microbial respiratory response to three pesticides.  

PubMed

The relationships between vermicompost chemical features, enzyme activities, community-level physiological profiles (CLPPs), fungal community structures, and its microbial respiratory response to pesticides were investigated. Fungal community structure of vermicomposts produced from damaged tomato fruits (DT), winery wastes (WW), olive-mill waste and biosolids (OB), and cattle manure (CM) were determined by denaturing gradient gel electrophoresis of 18S rDNA. MicroResp™ was used for assessing vermicompost CLPPs and testing the microbial response to metalaxyl, imidacloprid, and diuron. Vermicompost enzyme activities and CLPPs indicated that WW, OB, and DT had higher microbial functional diversity than CM. The microbiota of the former tolerated all three pesticides whereas microbial respiration in CM was negatively affected by metalaxyl and imidacloprid. The response of vermicompost microbiota to the fungicide metalaxyl was correlated to its fungal community structure. The results suggest that vermicomposts with higher microbial functional diversity can be useful for the management of pesticide pollution in agriculture. PMID:21865033

Fernández-Gómez, Manuel J; Nogales, Rogelio; Insam, Heribert; Romero, Esperanza; Goberna, Marta

2011-08-05

68

Hygienic quality of faeces treated in urine diverting vermicomposting toilets.  

PubMed

On-site sanitation solutions have gained much interest in recent years. One such solution is the urine diverting vermicomposting toilet (UDVT). This study evaluated the hygienic quality of the composted material in six UDVTs in operation in France. Samples were taken from three sampling positions in each toilet, with increasing distance from the fresh material. The concentration of Salmonella spp., Enterococcus spp., thermotolarent coliforms and coliphages were analysed and plotted against a number of variables. The variables found to have the greatest impact was the pH (for Enterococcus spp. and thermotolarent coliforms (TTC)) and time since last maintenance (coliphages). The pH was found to correlate with the material maturity. The current practise of maintenance can cause recontamination of the stabilised material and increase the risk of regrowth of pathogenic microorganisms. A modification in the maintenance procedure, in which a fourth maturation point is introduced, would eliminate this risk. UDVTs were found to be a good on-site sanitation option as the maintenance requirement is small and the system effectively reduced odour and concentration of pathogen and indicator organisms in human waste while keeping the accumulation of material down to a minimum. If the vermicompost is to be used for crops consumed raw, an additional sanitisation step is recommended. PMID:23932466

Lalander, Cecilia H; Hill, Geoffrey B; Vinnerås, Björn

2013-08-06

69

Sheep manure vermicompost supplemented with a native diazotrophic bacteria and mycorrhizas for maize cultivation.  

PubMed

An orthogonal experimental design L9 (3(4)) with 10 repetitions was used to investigate the effect of Glomus claroideum (0, 1 or 2g(-1) plant), G. fasciculatum (0, 1 or 2g plant(-1)), native diazotrophic bacteria (0, 10(3) and 10(5) UFC ml(-1)) and sheep manure vermicompost (0%, 5% and 10% v/v) on maize plant growth, N and P in leaves and mycorrhization percent. Vermicompost explained most of the variation found for leaf number, wet weight, stem height, and diameter. Both mycorrhizas increased the plant wet weight but G. fasciculatum the most. Mycorrhization increased the P content, but not the N content. Mycorrhizal colonization increased when diazotrophic bacteria and vermicompost were added. It was found that weight of maize plants cultivated in peat moss amended with vermicompost increased when supplemented with G. fasciculatum and diazotrophic bacteria. PMID:18291640

Gutiérrez-Miceli, F A; Moguel-Zamudio, B; Abud-Archila, M; Gutiérrez-Oliva, V F; Dendooven, L

2008-03-04

70

Dynamics of microbial communities related to biochemical parameters during vermicomposting and maturation of agroindustrial lignocellulose wastes.  

PubMed

Scarce information is available on the changes in abundance of microbial taxa during vermicomposting. Quantitative PCR and DGGE analysis were used to monitor variations in the microbial structure, relative abundance of four bacterial classes and fungi over the vermicomposting and maturation period of wet olive cake (O) and vine shoots (W). Multivariate correlation analysis between microbial structure and abundance, earthworm biomass and enzyme activities revealed similar and divergent interactions in both processes. Although Eisenia fetida development was different, significant correlations were found with ?-glucosidase activity and with bacterial and fungal structure. In the vermicomposting period of O and W, a decline was found in bacteria (94% and 77%), fungi (93% and 94%), and Gammaproteobacteria (56% and 71%) but an increase in Betaproteobacteria and Actinobacteria (62-79%). Alphaproteobacteria increased only in O (26%). Despite the different initial lignocellulose wastes, the mature vermicomposts were similar in microbial and biochemical properties. PMID:23948272

Castillo, Jean Manuel; Romero, Esperanza; Nogales, Rogelio

2013-07-25

71

Optimization of cow dung spiked pre-consumer processing vegetable waste for vermicomposting using Eisenia fetida.  

PubMed

This paper reports the optimization of cow dung (CD) spiked pre-consumer processing vegetable waste (PPVW) for vermicomposting using Eisenia fetida in a laboratory scale study. Vermicomposting process decreased carbon and organic matter concentration and increased N, P and K content in the vermicompost. The C:N ratio was decreased by 45-69% in different vermireactors indicating stabilization of the waste. The heavy metal content was within permissible limits of their application in agricultural soils. It has been concluded from the results that addition of PPVW up to 40% with CD can produce a good quality vermicompost. Whereas, growth and fecundity of E. fetida was best when reared in 20% PPVW+80% CD feed mixture. However, higher percentages of PPVW in different vermireactors significantly affected the growth and fecundity of worms. PMID:20951432

Garg, V K; Gupta, Renuka

2010-10-15

72

Sorption and desorption of the herbicide alachlor on humic acid fractions from two vermicomposts.  

PubMed

The present study focuses on the analysis of two vermicomposts, that have been used as alternative sources of restitution of soil organic matter, as well as sources of nutrient replacements. For this purpose, two samples of vermicomposts from different Brazilian regions (São Carlos-SP and Londrina-PR) were characterized according to their humic acid content. Both samples had a pH value near 7.0, and the humic acids present showed high cationic exchange capacities and low values for the C/N ratios. The infrared spectra showed bands that suggested the presence of aliphatic and aromatic components bound to phenolic, carboxylic and amide groups. The effect of vermicompost added to soil on the application of alachlor was evaluated. Alachlor sorption, Freundlich isotherms and alachlor desorption curves in the soil matrix and the vermicompost/soil mixture matrix were determined. PMID:11757739

Alves, M R; Landgraf, M D; Rezende, M O

2001-11-01

73

Chemical and spectroscopic characterization of water extractable organic matter during vermicomposting of cattle dung.  

PubMed

This work illustrated the characteristics and transformation of water extractable organic matter (WEOM) during vermistabilization (Eisenia fetida) of cattle dung by means of chemical and spectroscopic methods. The independent experiment conducted in triplicate was sampled at the 0, 7, 14, 21, 35, 60 and 90days. Results showed that the DOC kept steady around 2.7gkg(-1) after day 60 and the DOC/DON ratio decreased from 19.77 to 5.26 till the end of vermicomposting. On the other hand, vermicomposting decreased the aliphatic, proteinaceous, carbohydrates components and increased the aromaticity and oxygen-containing functional groups in the WEOM. Moreover, fluorescence spectra and fluorescence regional integration (FRI) results indicated that protein-like groups were degraded and fulvic and humic acid-like compounds were evolved during the vermicomposting process. In all, this study suggested the suitability of WEOM for monitoring the organics transformation and assessing the maturity in the vermicomposting. PMID:23416619

Lv, Baoyi; Xing, Meiyan; Yang, Jian; Qi, Wensheng; Lu, Yongsen

2013-01-16

74

Municipal solid waste management through vermicomposting employing exotic and local species of earthworms  

Microsoft Academic Search

A comparative study was conducted between exotic and local (epigeic-Eisenia fetida and anaecic-Lempito mauritii, respectively) species of earthworms for the evaluation of their efficacy in vermicomposting of municipal solid waste (MSW). Vermicomposting of MSW for 42 days resulted in significant difference between the two species in their performance measured as loss in total organic carbon, carbon–nitrogen ratio (C:N) and increase

S Kaviraj; Satyawati Sharma

2003-01-01

75

Livestock excreta management through vermicomposting using an epigeic earthworm Eisenia foetida  

Microsoft Academic Search

In India, millions of tones of livestock excreta are produced. Our study explores the potential of an epigeic earthworm Eisenia foetida to compost different livestock excreta (cow, buffalo, horse, donkey, sheep, goat and camel) into value added product (vermicompost)\\u000a at the laboratory scale. Vermicomposting resulted in lowering of pH, electrical conductivity, potassium and C:N ratio and\\u000a increase in nitrogen and

V. K. Garg; Y. K. Yadav; Aleenjeet Sheoran; Subhash Chand; Priya Kaushik

2006-01-01

76

Vermicomposting of different types of waste using Eisenia foetida: A comparative study  

Microsoft Academic Search

A study (100 days duration) was conducted to evaluate the efficiency of an exotic earthworm species (epigeic—Eisenia foetida) for decomposition of different types of organic substrates (kitchen waste, agro-residues, institutional and industrial wastes including textile industry sludge and fibres) into valuable vermicompost. The percentage of, nitrogen, phosphorous and potassium in vermicompost was found to increase while pH and total organic

Payal Garg; Asha Gupta; Santosh Satya

2006-01-01

77

Neem leaves as a source of fertilizer-cum-pesticide vermicompost  

Microsoft Academic Search

Vermicomposting of neem (Azadirachta indica A. Juss) was accomplished in ‘high-rate’ reactors operated at the earthworm (Eudrilus eugeniae) densities of 62.5 and 75 animals per litre of reactor volume. Contrary to the fears that neem––a powerful nematicide––might not be palatable to the annelids, the earthworms fed voraciously on the neem compost, converting upto 7% of the feed into vermicompost per

S. Gajalakshmi; S. A. Abbasi

2004-01-01

78

Vermicompost as natural adsorbent for removing metal ions from laboratory effluents  

Microsoft Academic Search

The use of vermicompost as an adsorbent to remove Cd(II), Cu(II), Pb(II) and Zn(II) ions from laboratory effluents is proposed. Parameters such as adsorption pH, vermicompost amount, flow rate and particle size range were studied. An optimum pH range (2.5–5.0) was found for metal removal. The flow rate affected only slightly the removal of Cd(II) ions (about 10%). A decrease

G. D Matos; M. A. Z Arruda

2003-01-01

79

High-rate composting–vermicomposting of water hyacinth ( Eichhornia crassipes, Mart. Solms)  

Microsoft Academic Search

In an attempt to develop a system with which the aquatic weed water hyacinth (Eichhornia crassipes, Mart. Solms) can be economically processed to generate vermicompost in large quantities, the weed was first composted by a `high-rate' method and then subjected to vermicomposting in reactors operating at much larger densities of earthworm than recommended hitherto: 50, 62.5, 75, 87.5, 100, 112.5,

S Gajalakshmi; E. V Ramasamy; S. A Abbasi

2002-01-01

80

SORPTION AND DESORPTION OF THE HERBICIDE ALACHLOR ON HUMIC ACID FRACTIONS FROM TWO VERMICOMPOSTS  

Microsoft Academic Search

The present study focuses on the analysis of two vermicomposts, that have been used as alternative sources of restitution of soil organic matter, as well as sources of nutrient replacements. For this purpose, two samples of vermicom-posts from different Brazilian regions (São Carlos—SP and Londrina—PR) were characterized according to their humic acid content. Both samples had a pH value near

Mirian R. Alves; Maria D. Landgraf; Maria O. O. Rezende

2001-01-01

81

Influences of vermicomposts on field strawberries: Part 2. Effects on soil microbiological and chemical properties  

Microsoft Academic Search

The effects of applications of food waste and paper waste vermicomposts on some soil chemical and biological properties were evaluated in field plots planted with strawberries. Six-week old strawberries (Fragaria ananasa, var. Chandler) were transplanted into 4.5m2 raised beds under a plastic tunnel structure measuring 9.14×14.6×3.6m. Vermicompost were applied at rates of 5 or 10tha?1 supplemented with inorganic fertilizers to

N. Q. Arancon; C. A. Edwards; P. Bierman

2006-01-01

82

Humic acid-like fractions in raw and vermicomposted winery and distillery wastes  

Microsoft Academic Search

Three different substrates from winery and distillery wastes including a spent grape marc (SGM), a mixture of SGM and lees cake (SGML) and a mixture of biosolid vinasse and vine shoots (BvS) were vermicomposted with Eisenia andrei for 8 months. The chemical changes occurring in the bulk substrates and in their humic acid-like (HAL) fractions were investigated. Vermicomposting produced a decrease

Esperanza Romero; César Plaza; Nicola Senesi; Rogelio Nogales; Alfredo Polo

2007-01-01

83

DEVELOPMENT OF MUSKMELON WITH DIFFERENT MIXTURES OF VERMICOMPOST:SAND UNDER GREENHOUSE CONDITIONS  

Microsoft Academic Search

In order to evaluate vermicompost:sand mixtures on the development of muskmelon under greenhouse conditions, four periods of watering were applied. Four types of vermicompost (VC) mixed with sand (S): 25:75, 30:70, 35:65 and 40:60 (VC:S;%:% by volume) were used. Each mixture, due to the water-holding capacity of VC, was watered at 24, 48, 72, or 96 h respectively. The watering

Alejandro Moreno-Reséndez; Homero Meza-Morales; Norma Rodríguez-Dimas; José Luis Reyes-Carrillo

2010-01-01

84

Reduction of bioavailability and leachability of heavy metals during vermicomposting of water hyacinth.  

PubMed

Vermicomposting of water hyacinth is a good alternative for the treatment of water hyacinth (Eichhornia crassipes) and subsequentially, beneficial for agriculture purposes. The bioavailability and leachability of heavy metals (Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr) were evaluated during vermicomposting of E. crassipes employing Eisenia fetida earthworm. Five different proportions (trials 1, 2, 3, 4, and 5) of cattle manure, water hyacinth, and sawdust were prepared for the vermicomposting process. Results show that very poor biomass growth of earthworms was observed in the highest proportion of water hyacinth (trial 1). The water soluble, diethylenetriaminepentaacetic acid (DTPA) extractable, and leachable heavy metals concentration (percentage of total heavy metals) were reduced significantly in all trials except trial 1. The total concentration of some metals was low but its water soluble and DTPA extractable fractions were similar or more than other metals which were present in higher concentration. This study revealed that the toxicity of metals depends on bioavailable fraction rather than total metal concentration. Bioavailable fraction of metals may be toxic for plants and soil microorganisms. The vermicomposting of water hyacinth by E. fetida was very effective for reduction of bioavailability and leachability of selected heavy metals. Leachability test confirmed that prepared vermicompost is not hazardous for soil, plants, and human health. The feasibility of earthworms to mitigate the metal toxicity and to enhance the nutrient profile in water hyacinth vermicompost might be useful in sustainable land renovation practices at low-input basis. PMID:23757026

Singh, Jiwan; Kalamdhad, Ajay S

2013-06-12

85

Influences of vermicomposts, produced by earthworms and microorganisms from cattle manure, food waste and paper waste, on the germination, growth and flowering of petunias in the greenhouse  

Microsoft Academic Search

Vermicomposts have been shown to promote the germination, growth, and yields of plants. This paper aims to demonstrate the effects of vermicomposts produced from three types of wastes on growth and flowering of petunias which are an important U.S. flowering crop.Vermicomposts, produced commercially from cattle manure, food wastes and paper wastes, were substituted at a range of different concentrations into

Norman Q. Arancon; Clive A. Edwards; Andrei Babenko; John Cannon; Paola Galvis; James D. Metzger

2008-01-01

86

Effect of the application of water hyacinth compost\\/vermicompost on the growth and flowering of Crossandra undulaefolia, and on several vegetables  

Microsoft Academic Search

The impact of the application of compost\\/vermicompost obtained from water hyacinth (Eichhornia crassipes, Mart. Solms) on plants was assessed in terms of growth and flowering of the angiosperm crossandra (Crossandra undulaefolia). Overall nine morphological, size, and yield attributes were studied in crossandra saplings raised on water hyacinth compost or vermicompost as compared to the untreated saplings. Application of vermicompost led

S Gajalakshmi; S. A Abbasi

2002-01-01

87

Changes in organic – C, N, P and K and enzyme activities in vermicompost of biodegradable organic wastes under liming and microbial inoculants  

Microsoft Academic Search

The aim of this work was to study the effect of different organic wastes, viz. cow dung, grass, aquatic weeds and municipal solid waste with lime and microbial inoculants on chemical and biochemical properties of vermicompost. Cow dung was the best substrate for vermicomposting. Application of lime (5g\\/kg) and inoculation of microorganisms increased the nutrient content in vermicompost and also

P. Pramanik; G. K. Ghosh; P. K. Ghosal; P. Banik

2007-01-01

88

Effect of aqueous extracts from vermicomposts on attacks by cucumber beetles ( Acalymna vittatum) (Fabr.) on cucumbers and tobacco hornworm ( Manduca sexta) (L.) on tomatoes  

Microsoft Academic Search

Vermicomposts are produced through interactions between earthworms and microorganisms in the breakdown of organic wastes. Aqueous extracts were prepared in commercial brewing equipment from vermicomposts produced from super-market food wastes. The ratio of vermicompost to water was one to five v:v, to produce a 20% aqueous solution which could be diluted to 5% and 10% concentrations. The effects of soil

Clive A. Edwards; Norman Q. Arancon; Marcus Vasko-Bennett; Ahmed Askar; George Keeney

2010-01-01

89

Vermicomposting of milk processing industry sludge spiked with plant wastes.  

PubMed

This work illustrates the vermistabilization of wastewater sludge from a milk processing industry (MPIS) unit spiked with cow dung (CD), sugarcane trash (ST) and wheat straw (WS) employing earthworms Eisenia fetida. A total of nine experimental vermibeds were established and changes in chemical parameters of waste material have been observed for 90 days. Vermistabilization caused significant reduction in pH, organic carbon and C:N ratio and substantial increase in total N, available P and exchangeable K. The waste mixture containing MPIS (60%)+CD (10%)+ST (30%) and MPIS (60%)+CD (10%)+WS (30%) had better waste mineralization rate among waste mixtures studied. The earthworm showed better biomass and cocoon numbers in all vermibeds during vermicomposting operation. Results, thus suggest the suitability of E. fetida for conversion of noxious industrial waste into value-added product for land restoration programme. PMID:22609678

Suthar, Surindra; Mutiyar, Pravin K; Singh, Sushma

2012-04-05

90

Effect of microbial inoculation during vermicomposting of different organic substrates on microbial status and quantification and documentation of acid phosphatase  

Microsoft Academic Search

In this experiment, three microbial strains were inoculated in two different organic wastes to study their effect on the humic acids content, acid phosphatase activity and microbial properties of the final stabilized products. Pyrophosphate extract of vermicomposts were analyzed through polyacrylamide gel electrophoresis to study the nature of a isozymes in different treatments. Results suggested that vermicomposting increased humic acids

P. Pramanik; G. K. Ghosh; P. Banik

2009-01-01

91

Sequential foliar application of vermicompost leachates improves marketable fruit yield and quality of strawberry ( Fragaria × ananassa Duch.)  

Microsoft Academic Search

The objective of the study was to determine the effect of foliar application of vermicompost leachates on growth, yield and quality of strawberry (Cv. Chandler). For this, three leachates collected from vermicomposting of cow dung (FCD), vegetable waste (FVW) and mixture of cow dung and vegetable waste in 1:2 ratio (FCVW) were used at 2mll?1 at monthly interval (total five

Rajbir Singh; R. K. Gupta; R. T. Patil; R. R. Sharma; R. Asrey; A. Kumar; K. K. Jangra

2010-01-01

92

Fourier transform-infrared spectroscopy and Gas chromatography-mass spectroscopy: Reliable techniques for analysis of Parthenium mediated vermicompost  

NASA Astrophysics Data System (ADS)

Fourier transform infrared spectroscopy (FT-IR) and Gas chromatography-mass spectroscopy have been carried out to investigate the chemical composition of Parthenium mediated vermicompost. Four different concentrations of Parthenium and cow dung mixtures were vermicomposted using the earthworms (Eudrilus eugeniae). FT-IR spectra reveal the absence of Parthenin toxin (sesquiterpene lactone) and phenols in vermicompost which was obtained from high concentration of cow dung mixed treatments. GC-MS analysis shows no phenolic compounds and predominant level of intermediate metabolites such as 4,8,12,16-Tetramethylheptadecan-4-olide (7.61%), 2-Pentadecanone, 6,10,14-trimethyl- (5.29%) and Methyl 16-methyl-heptadecanoate (4.69%) during the vermicomposting process. Spectral results indicated that Parthenin toxin and phenols can be eradicated via vermicomposting if mixed with appropriate quantity of cow dung.

Rajiv, P.; Rajeshwari, Sivaraj; Venckatesh, Rajendran

93

Effects of vermicomposts produced from food waste on the growth and yields of greenhouse peppers.  

PubMed

Vermicomposts, produced commercially from food wastes, were substituted at a range of different concentrations into a soil-less commercial bedding plant container medium, Metro-Mix 360 (MM360), to evaluate their effects on the growth and yields of peppers in the greenhouse. Six-week-old peppers (Capsicum annum L. var. California) were transplanted into 100%, 80%, 60%, 40%, 20% or 10% MM360 substituted with 0%, 10%, 20%, 40%, 60%, 80% and 100% vermicompost. All plants were watered three times weekly with 200 ppm Peter's Nutrient Solution from the time of transplanting up to 107 days. Peppers grown in potting mixtures containing 40% food waste vermicomposts and 60% MM360 yielded 45% more fruit weights and had 17% greater mean number of fruits than those grown in MM360 only. The mean heights, numbers of buds and numbers of flowers of peppers grown in potting mixtures containing 10-80% vermicompost although greater did not differ significantly from those of peppers grown in MM360. There were no positive correlations between the increases in pepper yields, and the amounts of mineral-N and microbial biomass-N in the potting mixtures, or the concentrations of nitrogen in the shoot tissues of peppers. Factors such as: an improvement of the physical structure of the potting medium, increases in populations of beneficial microorganisms and the potential availability of plant growth-influencing-substances produced by microorganisms in vermicomposts, could have contributed to the increased pepper yields obtained. PMID:15051075

Arancon, Norman Q; Edwards, Clive A; Atiyeh, Rola; Metzger, James D

2004-06-01

94

Bioconversion of filter mud using vermicomposting employing two exotic and one local earthworm species.  

PubMed

Three different earthworm species Eisenia fetida, Eudrilus eugeniae and Perionyx excavatus in individual (Monocultures) and combinations (Polycultures) were utilized to compare the suitability of worm species for vermicomposting of filter mud as well as the quality of the end product. The filter mud blended with saw dust can be directly converted into good quality fertilizer (vermicompost). Eight different reactors including three monocultures and four polycultures of E. fetida, E. eugeniae and P. excavatus and one control were used for the experiment. Vermicomposting resulted in significant reduction in C/N ratio, pH, total organic matter (TOC) but increase in electrical conductivity (EC), total nitrogen (TN), total phosphorus (TP) and macronutrients (K, Ca and Na). Oxygen uptake rate (OUR) dropped up to 1.64-1.95 mg/g (volatile solids) VS/day for monoculture reactors and 1.45-1.78 mg/g VS/day for polycultures reactors, respectively, after 45 days of vermicomposting. Cocoon production and the earthworm biomass increased as vermicomposting progressed. On an overall the mono as well as polyculture reactors produced high quality stable compost free from pathogens and no specific differentiation could be inferred between the reactors. PMID:19608410

Khwairakpam, Meena; Bhargava, Renu

2009-07-15

95

Impact of fly ash and phosphatic rock on metal stabilization and bioavailability during sewage sludge vermicomposting.  

PubMed

Sewage sludge (SS) was mixed with different proportions of fly ash (FA) and phosphoric rock (PR), as passivators, and earthworms, Eisenia fetida, were introduced to allow vermicomposting. The earthworm growth rates, reproduction rates, and metal (except Zn and Cd) concentrations were significantly higher in the vermireactors containing FA and PR than in the treatments without passivators. The total organic carbon (TOC) and total metal concentrations in the mixtures decreased, and the mixtures were brought to approximately pH 7 during vermicomposting. There were significant differences in the decreases in the metal bioavailability factors (BFs) between the passivator and control treatments, and adding 20% FA (for Cu and Zn) or 20% PR (for Pb, Cd, and As) to the vermicompost were the most effective treatments for mitigating metal toxicity. The BF appeared to be dependent on TOC in the all treatments, but was not closely dependent on pH in the different vermibeds. PMID:23567692

Wang, Longmian; Zhang, Yimin; Lian, Jianjun; Chao, Jianying; Gao, Yuexiang; Yang, Fei; Zhang, Leiyan

2013-03-15

96

[Optimization of vermicomposting of organics enriched with phosphorites with participation of phosphate-mobilizing microorganisms].  

PubMed

Active strains of microorganisms capable to mobilize phosphorus from poorly soluble compounds were isolated from the vermicompost. Representatives of Pseudomonas genus dominate in assemblages of phosphate-mobilizing humus microbiota. The strains Pseudomonas sp. 17 and Pseudomonas sp. 22, which promote liberation of the greatest quantity of water-soluble phosphorus were selected under vermicomposting of organics enriched with phosphorites with participation of active phosphate-mobilizing microorganisms. The use of compost derived with participation of Pseudomonas sp. 17 in cucumbers growth technologies makes the plants development better and raises the cultures productivity. PMID:20695224

Hatsenko, M V; Volkohon, V V

97

Effect of microbial inoculation during vermicomposting of different organic substrates on microbial status and quantification and documentation of acid phosphatase.  

PubMed

In this experiment, three microbial strains were inoculated in two different organic wastes to study their effect on the humic acids content, acid phosphatase activity and microbial properties of the final stabilized products. Pyrophosphate extract of vermicomposts were analyzed through polyacrylamide gel electrophoresis to study the nature of a isozymes in different treatments. Results suggested that vermicomposting increased humic acids content and acid phosphatase activity in organic substrates and microbial inoculation further enhanced the rate of humification and enzyme activity. Although humic acids content in different microorganism-inoculated vermicomposts were statistically at par, acid phosphatase activity in these treatments was significantly (P<0.05) different. Results revealed that microbial respiration was increased due to vermicomposting, but a reduction in microbial biomass was recorded after stabilization of organic wastes. Although vermicomposting increased the value of microbial quotient (qCO(2)), microbial inoculation did not show any significant effect on qCO(2). The zymogram revealed that two isozymes of acid phosphatase (group II and group III) were present in all vermicompost samples and higher acid phosphatase activity in fungi-inoculated vermicomposts might be due to the presence of an additional isozyme (group I) of acid phosphatase. PMID:18692380

Pramanik, P; Ghosh, G K; Banik, P

2008-08-08

98

Effects of humic acids from vermicomposts on plant growth  

Microsoft Academic Search

The interactions between earthworms and microorganisms can produce significant quantities of plant growth hormones and humic acids which act as plant regulators. Experiments were designed to evaluate the effects of humic acids extracted from vermicompost and compare them with the action of commercial humic acid in combination with a commercial plant growth hormone, indole acetic acid (IAA) which is a

Norman Q. Arancon; Clive. A. Edwards; Stephen Lee; Robert Byrne

2006-01-01

99

Potential of two epigeic and two anecic earthworm species in vermicomposting of water hyacinth  

Microsoft Academic Search

The potential of two epigeic species (Eudrilus eugeniae Kinberg, and Perionyx excavatus Perrier) and two anecic species (Lampito mauritii Kinberg and Drawida willsi Michaelson) of earthworms was assessed in terms of efficiency and sustainability of vermicomposting water hyacinth (Eichhornia crassipes, Mart. Solm.). In different vermireactors, each run in duplicate with one of the four species of earthworms, and 75 g

S Gajalakshmi; E. V Ramasamy; S. A Abbasi

2001-01-01

100

Using FAME profiles for the characterization of animal wastes and vermicomposts  

Microsoft Academic Search

This study investigated the possibility of fingerprinting different organic wastes (cow, pig and horse manure) and the vermicomposts produced by different earthworm species (Eisenia andrei, Eudrilus eugeniae and Lumbricus rubellus) analyzing the profiles of fatty acid methyl esters (FAMEs). We found clear differences between their microbial communities, demonstrating the power and sensitivity of the total FAME analysis. In addition, qualitative

Marta Lores; María Gómez-Brandón; Domingo Pérez-Díaz; Jorge Domínguez

2006-01-01

101

“In situ” vermicomposting of biological sludges and impacts on soil quality  

Microsoft Academic Search

A laboratory experiment was carried out to study soil quality amelioration through “in situ” vermicomposting of biological sludges. The experiment dealt with the stabilization, through the action of worms (Eisenia fetida), of five mixtures containing aerobic and anaerobic biological sludges spread on the soil surface. The results showed that by increasing the percentage of anaerobic sludge in the mixtures, the

G Masciandaro; B Ceccanti; C Garcia

2000-01-01

102

Composting of a crop residue through treatment with microorganisms and subsequent vermicomposting  

Microsoft Academic Search

Preliminary studies were conducted on wheat straw to test the technical viability of an integrated system of composting, with bioinoculants and subsequent vermicomposting, to overcome the problem of lignocellulosic waste degradation, especially during the winter season. Wheat straw was pre-decomposed for 40 days by inoculating it with Pleurotus sajor-caju, Trichoderma harzianum, Aspergillus niger and Azotobacter chroococcum in different combinations. This

Anshu Singh; Satyawati Sharma

2002-01-01

103

Potential of Eisenia foetida for Sustainable and Efficient Vermicomposting of Fly Ash  

Microsoft Academic Search

Vermicomposting of fly ash has been attempted, using red earthworm, Eisenia foetida. Fly ash, which was obtained from thermal power station, was mixed with cowdung in different proportions (20, 40, 60 and 80%). These mixtures were used as feed for earthworms, and after 30 days, vermicast recovery, worm zoomass and numbers of juveniles produced were recorded. A total of six

S. K. Gupta; Anamika Tewari; Richa Srivastava; R. C. Murthy; Saurabh Chandra

2005-01-01

104

Vermicomposting of cattle and goat manures by Eisenia foetida and their growth and reproduction performance  

Microsoft Academic Search

Vermicomposting is commonly adopted for the treatment of livestock organic wastes. In the present study, two types of livestock manure were used for culturing of the earthworm, Eisenia foetida. Each treatment group consisted of six replicates and worm vermicasts were examined after 5 weeks. The concentrations of total C, P and K in goat manure vermicasts were higher than those

T. C. Loh; Y. C. Lee; J. B. Liang; D. Tan

2005-01-01

105

Feasibility of vermicomposting dairy biosolids using a modified system to avoid earthworm mortality  

Microsoft Academic Search

A laboratory study was conducted to examine the feasibility of vermicomposting dairy biosolids (dairy sludge), either alone or with either of the bulking agents ? cereal straw or wood shavings, using the epigeic earthworm ? Eisinea andrei. Earthworms added directly to these three substrates died within 48 hours. A system was developed to overcome the toxic effect of unprocessed dairy

R. Nogales; C. Elvira; E. Benítez; R. Thompson; M. Gomez

1999-01-01

106

Competitive exclusion of Salmonella typhimurium in broilers fed with vermicompost and complex carbohydrates  

Microsoft Academic Search

Vermicompost (VC) was produced by earthworms fed with fresh chicken faeces, and was earth?like in appearance and odour. In three experiments, VC was sprinkled on the first feed of newly?hatched broiler chicks. Treated and control groups were challenged on day 6 by the addition of seeder chicks that had been inoculated orally with Salmonella typhimurium. Chickens were killed at intervals

J. L. Spencer; J. R. Chambers; H. W. Modler

1998-01-01

107

Comparison of the effectiveness of composting and vermicomposting for the biological stabilization of cattle manure  

Microsoft Academic Search

Cattle manure is produced in large quantities in industrial breeding facilities and the storage and\\/or spreading of this waste on land may cause contamination of the atmosphere, soil and water. The aim of the present study was to evaluate the effectiveness of the active phases of composting, vermicompo- sting, and also a combination of composting and vermicomposting for reducing the

Cristina Lazcano; María Gómez-Brandón; Jorge Domínguez

2008-01-01

108

Effects of vermicomposts on growth and marketable fruits of field-grown tomatoes, peppers and strawberries  

Microsoft Academic Search

Summary Vermicomposts, produced commercially from cattle manure, market food waste and recycled paper waste, were applied to small replicated field plots planted with tomatoes (Lycopersicon esculentum) and bell peppers (Capsicum anuum grossum) at rates of 10 t ha-1 or 20 t ha-1 in 1999 and at rates of 5 t ha-1 or 10 t ha-1 in 2000. Food waste and

Norman Q. Arancon; Clive A. Edwards; Peter Bierman; James D. Metzger; Stephen Lee; Christie Welch

2003-01-01

109

Integrating composting and vermicomposting in the treatment and bioconversion of biosolids  

Microsoft Academic Search

Traditional thermophillic composting is commonly adopted for treatment of organic wastes or for production of organic\\/natural fertilizers. A related technique, called vermicomposting (using earthworms to breakdown the organic wastes) is also becoming popular. These two techniques have their inherent advantages and disadvantages. The integrated approach suggested in this study borrows pertinent attributes from each of these two processes and combines

P. M Ndegwa; S. A Thompson

2001-01-01

110

Comparison of the effectiveness of composting and vermicomposting for the biological stabilization of cattle manure.  

PubMed

Cattle manure is produced in large quantities in industrial breeding facilities and the storage and/or spreading of this waste on land may cause contamination of the atmosphere, soil and water. The aim of the present study was to evaluate the effectiveness of the active phases of composting, vermicomposting, and also a combination of composting and vermicomposting for reducing the polluting potential and for stabilizing cattle manure in the short-term. For this, the degree of decomposition as well as the microbial activity and microbial composition of the resulting products after the active phase of composting and vermicomposting were analysed. None of the treatments significantly reduced the dissolved organic carbon and dissolved organic nitrogen contents relative to the control, and therefore more time may be required for stabilization. Nevertheless, the lowest values of microbial biomass and activity corresponded to the earthworm-worked substrates, in which fungal growth was also promoted; the combined treatment (composting + vermicomposting) was the most effective in terms of stabilizing the cattle manure. Moreover, earthworms promoted the retention of nitrogen and gradual release of P, as well as a reduction in electrical conductivity, thereby producing improved substrates for agricultural use. PMID:18511100

Lazcano, Cristina; Gómez-Brandón, María; Domínguez, Jorge

2008-06-03

111

Effects of C-to-N ratio on vermicomposting of biosolids  

Microsoft Academic Search

The role of organic carbon and inorganic nitrogen for cell synthesis, growth, and metabolism is important in all living organisms. To provide proper nutrition for earthworms during vermicomposting, carbon and nitrogen must be present in the substrates at the correct ratio. The usual practice is to arbitrarily add either a rich nitrogenous material, or a rich carbonaceous material to the

Pius M. Ndegwa; S. A. Thompson

2000-01-01

112

Production of Eisenia fetida and vermicompost from feed-lot cattle manure  

Microsoft Academic Search

Significant reductions in total mass of feedlot cattle manure were obtained by the intensive activity of earthworms. The process yielded two products: residual vermicompost, and an increase in earthworm biomass. Various modes of manure application were made to a prepared bedding (or support material), the most successful being a surface (vertical) application which resulted in a reduction of 30% of

Allan Mitchell

1997-01-01

113

Vermicomposting of industrially produced woodchips and sewage sludge utilizing Eisenia fetida  

Microsoft Academic Search

Adult Eisenia fetida were used to vermicompost woodchips (WC) and sewage sludge (SS) that are produced as waste product by platinum mines. The aims of the study were to examine the growth and reproductive success of the worms over 84 days to determine long-term feasibility of large-scale implementation and monitor the bioconcentration of heavy metals and the effects of microorganisms

M. S. Maboeta; L. van Rensburg

2003-01-01

114

Influences of vermicomposts on field strawberries: 1. effects on growth and yields.  

PubMed

Vermicomposts processed commercially from food wastes and paper wastes were applied, to 4.5 m(2) field plots, under high plastic hoop tunnels, at rates of 5 or 10 tha(-1) to evaluate their effects on the growth and yields of strawberries (Fragaria ananasa) var. 'Chandler'. The vermicomposts were incorporated into the top 10 cm of soil and supplemented, based on chemical analyses, with amounts of inorganic NPK fertilizers calculated to equalize the initial fertilizer rates of 85-155-125 kgha(-1) NPK applied to the inorganic fertilizer plots. All treatments were replicated four times, in a completely randomized design, at two field sites on Doles silt loam or Hoytville silty clay loam at Piketon and Fremont, Ohio, respectively. Vermicompost applications increased strawberry growth and yields significantly; including increases of up to 37% in leaf areas, 37% in plant shoot biomass, 40% in numbers of flowers, 36% in numbers of plant runners and 35% in marketable fruit weights. These responses seemed not to be dose-dependent, since strawberries at one site grew fastest and yielded most in response to the 10 tha(-1) vermicompost application rate, whereas they responded positively and similarly to both the 5 and 10 tha(-1) rates of applications at the other site. These responses could not have been mediated by availability of macronutrients, since all plots were supplemented with inorganic fertilizers, to equalize macronutrient inputs for all treatments, but based on other research in our laboratory could have been due to production of plant growth regulators by microorganisms during vermicomposting. PMID:15051076

Arancon, N Q; Edwards, C A; Bierman, P; Welch, C; Metzger, J D

2004-06-01

115

Municipal solid waste management through vermicomposting employing exotic species of earthworm Eudrilus eugeniae.  

PubMed

Majority of municipal (urban) solid waste (MSW) is disposed of in landfills (anaerobic composting). However, this disposal system is reported to produce hazardous environmental impacts and new policies are initiated to protect the environment from such impacts by discouraging the practice of disposal of solid waste in landfills. Eco-friendly disposal alternatives to landfills need to be explored. One of the technological options for treatment and disposal of organic solid wastes is vermicomposting. Commercial vermicomposting is reported to be practicable for treatment and disposal of many organic solids and byproducts in agricultural production and processing industries. However, this alternative has not been tried for MSW on large scale. This paper highlights the application of vermicomposting for treatment of organic solid waste, generated at urban residential area at Pune [organic component of this urban solid waste (MSW)]. Vermicomposting was tried on this segregated solid waste using exotic species of earthworm--Eudrilus eugeniae--commonly called 'African Night Crawler'. Bench scale reactor studies were carried out on organic solid waste under controlled optimum environmental conditions (moisture content: 48-52 percent, pH: 7.0-7.2, temperature: ambient), with variable vermi-loading [40-80 g of worms/kg of urban solid waste (MSW)]. Characteristics of solid waste were monitored through conventional parameters and additional environmental parameters like BOD5 and COD. The results of investigative studies are encouraging and indicate that organic solid waste can be treated in a reasonable period of 32-34 days through vermicomposting with around 60 percent reduction in the volume. PMID:22324158

Chaudhari, R D; Datar, M T; Babookani, M Rabiei

2011-01-01

116

Transformation and availability of nutrients and heavy metals during integrated composting-vermicomposting of sewage sludges.  

PubMed

Transformation and availability of nutrients and some heavy metals were assessed during the integrated composting-vermicomposting of both primary sewage sludge (PSS) and waste activated sewage sludge (WAS) using matured vermicompost as indigenous bulking material and employing Eisenia fetida as earthworm species. Vermicomposting resulted in significant increase in total N (TN) (PSS: 41.7-64.6%, F=11.6, P<0.05; WAS: 36.4-58.6%, F=6.4, P<0.05), water soluble N (WSN) (PSS: 37.1-50.5%, F=30.1, P<0.05; WAS: 40.1-53.0%, F=27.6, P<0.05), total P (TP) (PSS: 39.9-69.8%, F=27.1, P<0.05; WAS: 32.2-56.6%, F=21.4, P<0.05) and water soluble P (WSP) (PSS: 25.2-34.3%, F=163.9, P<0.05; WAS: 24.1-34.2%, F=144.3, P<0.05) as compared to the initial compost material depending on different experimental conditions. The study demonstrated that the vermicomposting significantly improved the availability of nutrients in sewage sludges. In addition, vermicomposting considerably reduced the availability of heavy metals except Fe and Mn, presumably by forming organic-bound complexes in spite of several fold increase in their total content. The environmental conditions (i.e., temperature and relative humidity), in general, showed significant effect on the transformation and availability of nutrients and heavy metals. There was no effect of earthworm density on the transformation and availability of heavy metals and nutrients except N and P, possibly due to prior exposure during acclimation period in sewage sludge. PMID:22277776

Hait, Subrata; Tare, Vinod

2012-01-25

117

Vermicomposting of sugar industry waste (press mud) mixed with cow dung employing an epigeic earthworm Eisenia fetida.  

PubMed

In India, millions of tons of press mud (PM) are generated by sugar mills every year. This paper reports the potential of vermitechnology to convert sugar industry waste PM mixed with cow dung (CD) into vermicompost, employing an epigeic earthworm Eisenia fetida. A total of six different reactors were established having different ratios of PM and CD including one control (CD only). The growth and fecundity of E. fetida was monitored for 13 weeks. Maximum growth was recorded in 100% CD, but earthworms grew and reproduced favourably up to 1:1 PM and CD feed composition. However, greater percentages of PM in different reactors significantly affected the growth and fecundity of worms. Vermicomposting resulted in a decrease in carbon concentration and an increase in nitrogen, phosphorus and calcium concentrations of the vermicompost. Investigations indicated that vermicomposting could be an alternative technology for the management of PM into useful fertilizing material, if mixed at maximum 50% with CD. PMID:19748951

Sangwan, P; Kaushik, C P; Garg, V K

2009-09-11

118

Recycling of organic wastes for the production of vermicompost and its response in rice–legume cropping system and soil fertility  

Microsoft Academic Search

Investigations were made to recycle agricultural and agro-industrial wastes for the production of vermicompost using earthworms (Eudrilus eugeniae). Its response was studied in a rice–legume cropping system. Different combinations of coirpith\\/weeds and cowdung\\/sugarcane pressmud\\/biodigested slurry were tried for vermicomposting. The study showed that biodigested slurry and weeds was found to be an ideal combination for vermicomposting considering the nutrient content

A Jeyabal; G Kuppuswamy

2001-01-01

119

Chemical and microbiological changes during vermicomposting of coffee pulp using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis) species.  

PubMed

Coffee pulp is the main solid residue from the wet processing of coffee berries. Due to presence of anti-physiological and anti-nutritional factors, coffee pulp is not considered as adequate substrate for bioconversion process by coffee farmers. Recent stringent measures by Pollution Control authorities, made it mandatory to treat all the solid and liquid waste emanating from the coffee farms. A study was conducted to evaluate the efficiency of an exotic (Eudrilus eugeniae) and a native earthworm (Perionyx ceylanesis) from coffee farm for decomposition of coffee pulp into valuable vermicompost. Exotic earthworms were found to degrade the coffee pulp faster (112 days) as compared to the native worms (165 days) and the vermicomposting efficiency (77.9%) and vermicompost yield (389 kg) were found to significantly higher with native worms. The multiplication rate of earthworms (280%) and worm yield (3.78 kg) recorded significantly higher with the exotic earthworms. The percentage of nitrogen, phosphorous, potassium, calcium and magnesium in vermicompost was found to increase while C:N ratio, pH and total organic carbon declined as a function of the vermicomposting. The plant nutrients, nitrogen (80.6%), phosphorus (292%) and potassium (550%) content found to increase significantly in the vermicompost produced using native earthworms as compared to the initial values, while the calcium (85.7%) and magnesium (210%) content found to increase significantly in compost produced utilizing exotic worms. Vermicompost and vermicasts from native earthworms recorded significantly higher functional microbial group's population as compared to the exotic worms. The study reveals that coffee pulp can be very well used as substrate for vermicomposting using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis). PMID:20922463

Raphael, Kurian; Velmourougane, K

2010-10-05

120

Organic matter humification by vermicomposting of cattle manure alone and mixed with two-phase olive pomace  

Microsoft Academic Search

The chemical changes occurring in a cattle manure (CM) and a mixture of two-phase olive pomace and CM (OP+CM) after vermicomposting with Eisenia andrei for eight months were evaluated. Further, humic acid (HA)-like fractions were isolated from the two substrates before and after the vermicomposting process, and analyzed for elemental and acidic functional group composition, and by ultraviolet\\/visible, Fourier transform

C. Plaza; R. Nogales; N. Senesi; E. Benitez; A. Polo

2008-01-01

121

Chemolytic and solid-state spectroscopic evaluation of organic matter transformation during vermicomposting of sugar industry wastes  

Microsoft Academic Search

The molecular structure of humic acid (HA) extracted was investigated by FT-IR and 13C CP\\/MAS NMR spectroscopy during the vermicomposting of sugar industry wastes, viz. pressmud, trash and bagasse for 60days. A rapid decrease in C\\/N and lignocellulosic (lignin, cellulose, hemicellulose) content was observed in vermicompost during early phase of the process. The FT-IR and 13C CP\\/MAS NMR spectra of

Biswarup Sen; T. S. Chandra

2007-01-01

122

Efficacy of Vermicompost against fertilizers on Cicer and Pisum and on population diversity of N2 fixing bacteria.  

PubMed

Vermicompost is a very important biofertilizer produced through the artificial cultivation of worms i.e. Vermiculture. Vermicompost is enriched with all beneficial soil bacteria and also contain many of the essential plant nutrients like N, P, K and micronutrients. It increases soil aeration, texture and jilt. In this work, study is being carried out to find out the effect of different fertilizers such as DAF, FYM and Vermicompost on various morphological parameters and on the in vitro growth of bacterial colonies and its diversity in relation to two important leguminous plants such as Pisum sp. and Cicer sp. Results showed that plant grown in Vermicompost pretreated soil exhibited maximum increase in all morphological parameters such as root length, shoot length, number of root branches, number of stem branches, number of leaves, number of flowers, number of pods and number of root nodules in four months sampling in comparison to untreated, FYM treated and DAP treated soils. Further in Vermicompost pretreated soil, number of N2 fixing bacterial colony was maximum and showed highest diversity indices (1.6 and 0.99 and 2.0 and 0.99 for Cicer sp. and Pisum sp. respectively) than FYM, DAP and untreated control. Thus not only does the Vermicompost stimulate plant growth but also it increases the N2 fixing bacterial population in soil and also its diversity. PMID:21046998

Sinha, Jayanta; Biswas, Chanchal Kumar; Ghosh, Arup; Saha, Amit

2010-05-01

123

Changes in the chemical characteristics of water-extracted organic matter from vermicomposting of sewage sludge and cow dung.  

PubMed

The chemical changes of water-extractable organic matter (WEOM) from five different substrates of sewage sludge enriched with different proportions of cow dung after vermicomposting with Eisenia fetida were investigated using various analytical approaches. Results showed that dissolved organic carbon, chemical oxygen demand, and C/N ratio of the substrates decreased significantly after vermicomposting process. The aromaticity of WEOM from the substrates enhanced considerably, and the amount of volatile fatty acids declined markedly, especially for the cow dung substrate. Gel filtration chromatography analysis showed that the molecular weight fraction between 10(3) and 10(6) Da became the main part of WEOM in the final product. 1H nuclear magnetic resonance spectra revealed that the proportion of H moieties in the area of 0.00-3.00 ppm decreased, while increasing at 3.00-4.25 ppm after vermicomposting. Fluorescence spectra indicated that vermicomposting caused the degradation of protein-like groups, and the formation of fulvic and humic acid-like compounds in the WEOM of the substrates. Overall results indicate clearly that vermicomposting promoted the degradation and transformation of liable WEOM into biological stable substances in sewage sludge and cow dung alone, as well as in mixtures of both materials, and testing the WEOM might be an effective way to evaluate the biological maturity and chemical stability of vermicompost. PMID:22230755

Xing, Meiyan; Li, Xiaowei; Yang, Jian; Huang, Zhidong; Lu, Yongsen

2011-11-28

124

Composting of sugar-cane waste by-products through treatment with microorganisms and subsequent vermicomposting.  

PubMed

The waste by-products of the sugar-cane industry, bagasse (b), pressmud (p) and trash (t) have been subjected to bioinoculation followed by vermicomposting to shorten stabilization time and improve product quality. Press-mud alone and in combination with other by-products of sugar processing industries was pre-decomposed for 30 days by inoculation with combination of Pleurotus sajorcaju, Trichoderma viridae, Aspergillus niger and Pseudomonas striatum. This treatment was followed by vermicomposting for 40 days with the native earthworm, Drawida willsi. The combination of both treatments reduced the overall time required for composting to 20 days and accelerated the degradation process of waste by-products of sugar processing industry, thereby producing a nutrient-enriched compost product useful for sustaining high crop yield, minimizing soil depletion and value added disposal of waste materials. PMID:20403689

Kumar, Rahul; Verma, Deepshikha; Singh, Bhanu L; Kumar, Umesh; Shweta

2010-04-18

125

Changes in chemical and microbiological properties of rabbit manure in a continuous-feeding vermicomposting system.  

PubMed

In the present study the potential of the earthworm Eisenia fetida to process large amounts of waste was evaluated through continuous feeding reactors in which new layers of rabbit manure were added sequentially to form an age gradient inside the reactors. An optimal moisture level, ranging from 66% to 76%, was maintained throughout the process using an automatic watering system. The pH was close to 8.3, but decreased to 7.6 after 200 d of vermicomposting. No changes in electrical conductivity through the profile of layers were detected. Based on comparisons of phospholipid fatty acid (PLFA) profiles and microbial activity measurements (basal respiration), a decrease in the levels of bacteria and fungi in layers corresponding to vermicomposting times of more than 200 d occurred. This points to a higher degree of stabilisation in the final product, which is of utmost importance for its safe use as an organic amendment. PMID:23196253

Gómez-Brandón, María; Lores, Marta; Domínguez, Jorge

2012-11-02

126

Effects of vermicomposts produced from food waste on the growth and yields of greenhouse peppers  

Microsoft Academic Search

Vermicomposts, produced commercially from food wastes, were substituted at a range of different concentrations into a soil-less commercial bedding plant container medium, Metro-Mix 360 (MM360), to evaluate their effects on the growth and yields of peppers in the greenhouse. Six-week-old peppers (Capsicum annum L. var. California) were transplanted into 100%, 80%, 60%, 40%, 20% or 10% MM360 substituted with 0%,

Norman Q. Arancon; Clive A. Edwards; Rola Atiyeh; James D. Metzger

2004-01-01

127

Waste recycling: Utilization of coffee grounds and kitchen waste in vermicomposting  

Microsoft Academic Search

Vermicomposting using Lumbricus rubellus for 49 days was conducted after 21 days of pre-composting. Three different combination of treatments were prepared with eight replicates for each treatment namely cow dung: kitchen waste in 30:70 ratio (T1), cow dung: coffee grounds in 30:70 ratio (T2), and cow dung: kitchen waste: coffee grounds in 30:35:35 ratio (T3). The multiplication of earthworms in

A. J. Adi; Z. M. Noor

2009-01-01

128

Feasibility of vermicomposting in biostabilization of sludge from a distillery industry  

Microsoft Academic Search

The feasibility of vermicomposting technology to stabilize the distillery industry sludge mixed with a bulking agent (cow dung) in different proportions viz. 20% (T1), 40% (T2), 60% (T3) and 80% (T4), was tested using composting earthworm Perionyx excavatus for 90 days. The vermitreated sludge was evaluated for different physico-chemical parameters and all vermibeds expressed a significant decrease in pH (10.5–19.5%) organic

Surindra Suthar; Sushma Singh

2008-01-01

129

Suitability of aquaculture effluent solids mixed with cardboard as a feedstock for vermicomposting  

Microsoft Academic Search

Recirculating aquaculture systems are highly intensive culture systems that actively filter and reuse water, thus minimizing water requirements and creating relatively small volumes of concentrated waste (compared to flow-through aquaculture systems). Vermicomposting, which uses earthworms to stabilize and transform organic wastes into valuable end-products, has been proposed as an alternative treatment technology for high-moisture-content organic wastes from agricultural, industrial and

Lori Marsh; Scott Subler; Sudanshu Mishra; Michele Marini

2005-01-01

130

Use of vermicompost extract as an aluminium inhibitor in aqueous solutions  

Microsoft Academic Search

Vermicompost extract (VCE) demonstrated the ability to raise the measured pH level of an acid soil thus showing a potential to limit aluminium toxicity. The relatively high proportion of humic substances (60% of VCE solid matter) suggested the possibility of formation of stable chelates with aluminium ions. A rate?based colorimetric method was utilised measuring at 585 nm the aluminium?pyrocatechol violet

D. Alter; A. Mitchell

1992-01-01

131

Chemical composition and bioactivity properties of size-fractions separated from a vermicompost humic acid  

Microsoft Academic Search

Preparative high performance size-exclusion chromatography (HPSEC) was applied to humic acids (HA) extracted from vermicompost in order to separate humic matter of different molecular dimension and evaluate the relationship between chemical properties of size-fractions (SF) and their effects on plant root growth. Molecular dimensions of components in humic SF was further achieved by diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR) based

Luciano P. Canellas; Alessandro Piccolo; Leonardo B. Dobbss; Riccardo Spaccini; Fábio L. Olivares; Daniel B. Zandonadi; Arnoldo R. Façanha

2010-01-01

132

Pilot-scale study of efficient vermicomposting of agro-industrial wastes  

Microsoft Academic Search

Pilot-scale vermicomposting was explored using Eudrilus eugeniae for 90 days with 45 days preliminary decomposition using different agro-industrial wastes as substrates. Spent wash and pressmud were mixed together (referred to as PS) and then combined with cow dung (CD) at five different ratios of PS:CD, namely, 25:75 (T1), 50:50 (T2), 75:25 (T3), 85:15 (T4) and 100 (T5), with two replicates

Vaidyanathan Vinoth Kumar; M. Shanmugaprakash; J. Aravind; S. Karthick Raja Namasivayam

2012-01-01

133

Composting of sugar-cane waste by-products through treatment with microorganisms and subsequent vermicomposting  

Microsoft Academic Search

The waste by-products of the sugar-cane industry, bagasse (b), pressmud (p) and trash (t) have been subjected to bioinoculation followed by vermicomposting to shorten stabilization time and improve product quality. Press-mud alone and in combination with other by-products of sugar processing industries was pre-decomposed for 30days by inoculation with combination of Pleurotus sajorcaju, Trichoderma viridae, Aspergillus niger and Pseudomonas striatum.

Rahul Kumar; Deepshikha Verma; Bhanu L. Singh; Umesh Kumar; Shweta

2010-01-01

134

Enhancement of wood waste decomposition by microbial inoculation prior to vermicomposting.  

PubMed

To investigate the feasibility of microbial pre-decomposition of timber wastes to quality production of vermicompost with higher agronomic value, timber wastes were inoculated with different combinations of the fungi Phanerochete chrysosporium, Trichoderma reesei, Aspergillus niger and the bacteria Azotobacter chroococcum (MTCC 3853) and Bacillus cereus (MTCC 4079) and incubated at 28-30 °C in a mechanical composter. The inoculation enhanced the degradation of timber wastes, increased total nitrogen and improved the quality and enhanced production of vermicompost generated with the native earthworm Drawida willsi Michelsen. Total nitrogen increased from 0.16% to 1.52% and total organic carbon (TOC) decreased from 42% to 13%. Out of 10 microbial combinations tested for pre-decomposition, the combination of P. chrysosporium+T. reesei was found best in terms of ligno-cellulosic decomposition, and P. chrysosporium+A. niger+B. cereus with respect of cast output. The study shows that microbial pre-decomposition of timber wastes to produce quality vermicompost is a feasible technology. PMID:21036037

Kumar, Rahul; Shweta

2010-10-01

135

Swine manure vermicomposting via housefly larvae (Musca domestica): the dynamics of biochemical and microbial features.  

PubMed

Improper handling of animal manure generated from concentrated swine operations greatly deteriorates water ecosystems. In this study, a full-scale vermireactor using housefly larvae (Musca domestica) was designed to investigate the effectiveness and efficiency of swine manure reduction, and to explore the associated biochemical-biological mechanisms. The one-week larvae vermireactor resulted in a total weight reduction rate of 106±17 kg/(m(3) d) and moisture reduction of 80.2%. Microbial activities in manure decreased by 45% after vermicomposting, while the activities of cellulose, proteases, and phosphatases in the vermicompost were significantly 69 times, 48%, and 82% lower than those in raw manure, respectively. The vermicompost was exclusively dominated by Entomoplasma somnilux, Proteobacterium, and Clostridiaceae bacterium where the microbial diversity was decreased from 2.57 in raw manure to 1.77. Correlation coefficients statistic showed that organic C might be a key indicator of the biochemical features and microbial functions of the larvae vermireactor. PMID:22728759

Zhang, ZhiJian; Wang, Hang; Zhu, Jun; Suneethi, Sundar; Zheng, JianGuo

2012-05-18

136

Pilot-scale study of efficient vermicomposting of agro-industrial wastes.  

PubMed

Pilot-scale vermicomposting was explored using Eudrilus eugeniae for 90 days with 45 days preliminary decomposition using different agro-industrial wastes as substrates. Spent wash and pressmud were mixed together (referred to as PS) and then combined with cow dung (CD) at five different ratios of PS:CD, namely, 25:75 (T1), 50:50 (T2), 75:25 (T3), 85:15 (T4) and 100 (T5), with two replicates for each treatment. All vermibeds expressed a significant decrease in pH (11.4-14.8%), organic carbon (4.2-30.5%) and an increase in total nitrogen (6-29%), AP (5-29%), exchangeable potash (6-21%) and turnover rate (52-66%). Maximum mortality (18.10%) of worms was recorded in T5 treatment. A high manurial value and a matured product was achieved in T3 treatment. The data reveal that pressmud mixed with spent wash can be decomposed through vermicomposting and can help to enhance the quality of vermicompost. PMID:22720423

Kumar, Vaidyanathan Vinoth; Shanmugaprakash, M; Aravind, J; Namasivayam, S Karthick Raja

137

Organic matter humification by vermicomposting of cattle manure alone and mixed with two-phase olive pomace.  

PubMed

The chemical changes occurring in a cattle manure (CM) and a mixture of two-phase olive pomace and CM (OP+CM) after vermicomposting with Eisenia andrei for eight months were evaluated. Further, humic acid (HA)-like fractions were isolated from the two substrates before and after the vermicomposting process, and analyzed for elemental and acidic functional group composition, and by ultraviolet/visible, Fourier transform infrared and fluorescence spectroscopies. Before vermicomposting, the HA-like fractions featured a prevalent aliphatic character, large C contents, small O and acidic functional group contents, a marked presence of proteinaceous materials and polysaccharide-like structures, extended molecular heterogeneity and small degrees of aromatic ring polycondensation, polymerisation and humification. After vermicomposting, the total extractable C and HA-C contents in the bulk substrates increased, and the C and H contents, aliphatic structures, polypeptidic components and carbohydrates decreased in the HA-like fractions, whereas O and acidic functional group contents increased. Further, an adequate degree of maturity and stability was achieved after vermincomposting, and the HA-like fractions, especially that from OP+CM, approached the characteristics typical of native soil HA. Vermicomposting was thus able to promote organic matter humification in both CM alone and in the mixture OP+CM, thus enhancing the quality of these materials as soil organic amendments. PMID:17997303

Plaza, C; Nogales, R; Senesi, N; Benitez, E; Polo, A

2007-11-07

138

Compositional and functional features of humic acid-like fractions from vermicomposting of sewage sludge and cow dung.  

PubMed

The chemical changes occurring in five different substrates of sewage sludge spiked with different proportions of cow dung after vermicomposting with Eisenia foetida for 90 days were investigated. Their humic acid-like (HAL) fractions were isolated to determine the elemental and functional composition, and structural and functional characteristics using ultraviolet/visible, Fourier transform infrared (FT-IR) and fluorescence spectroscopies and scanning electron microscopy. After vermicomposting, the total organic C and C/N ratio decreased, and the total extractable C and humic acid (HA) C increased in all substrates. In the HAL fractions, the C and H contents, C/N and C/O and aliphatic structures, proteinaceous components and carbohydrates decreased, while the O and N and acidic functional group contents and C/H ratio, aromaticity and polycondensation structures increased. Further, the results suggest that the addition of cow dung to sewage sludge could improve the quality of organic matter humification of the substrates. The structures of HAL fractions in vermicomposts resembled those typical of soil HA, especially the vermicompost of cow dung alone. Scanning electron microscopy showed the microstructure of HAL fraction in final product became close-grained and lumpy. Overall results indicate that vermicomposting was an efficient technology for promoting organic matter (OM) humification in sewage sludge and cow dung alone, as well as in mixtures of both materials, improving their quality and environmental safety as a soil OM resource for utilization as soil amendments. PMID:21030148

Li, Xiaowei; Xing, Meiyan; Yang, Jian; Huang, Zhidong

2010-09-29

139

Critical tests for determination of microbiological quality and biological activity in commercial vermicompost samples of different origins.  

PubMed

The aim of the present paper was to show that differences in biological activity among commercially produced vermicompost samples can be found by using a relatively simple test system consisting of microorganism tests on six microbiological media and soilless seedling growth tests with four vegetable crop species. Significant differences in biological properties among analyzed samples were evident both at the level of microbial load as well as plant growth-affecting activity. These differences were mostly manufacturer- and feedstock-associated, but also resulted from storage conditions of vermicompost samples. A mature vermicompost sample that was produced from sewage sludge still contained considerable number of Escherichia coli. Samples from all producers contained several potentially pathogenic fungal species such as Aspergillus fumigatus, Pseudallescheria boidii, Pseudallescheria fimeti, Pseudallescheria minutispora, Scedosporium apiospermum, Scedosporium prolificans, Scopulariopsis brevicaulis, Stachybotrys chartarum, Geotrichum spp., Aphanoascus terreus, and Doratomyces columnaris. In addition, samples from all producers contained plant growth-promoting fungi from the genera Trichoderma and Mortierella. The described system can be useful both for functional studies aiming at understanding of factors affecting quality characteristics of vermicompost preparations and for routine testing of microbiological quality and biological activity of organic waste-derived composts and vermicomposts. PMID:23504062

Grantina-Ievina, Lelde; Andersone, Una; Berkolde-P?re, Dace; Nikolajeva, Vizma; Ievinsh, Gederts

2013-03-16

140

Continuous-feeding vermicomposting as a recycling management method to revalue tomato-fruit wastes from greenhouse crops.  

PubMed

Huge quantities of discarded fruits generated from greenhouse crops represent a worldwide environmental problem. The aim of this work was to assess the efficiency of vermicomposting as a recycling management option for biotransforming tomato-fruit wastes from greenhouses into an organic nutrient-rich product available for agricultural purposes. A pilot vermireactor was constructed. It was provided with a manure layer, where an initial population of Eisenia fetida was introduced and fed continuously at a high organic loading rate (13.6 kg TOC m(-3)wk(-1)) for 150 days. Vermicompost chemical and enzymatic parameters as well as the bacterial and fungal community structure were determined for 210 days (vermicomposting plus a maturation period). Earthworm biomass increased after 90 days, and then declined due to increasing pH, electrical conductivity and ammonium concentration. The temporal patterns of dehydrogenase, ?-glucosidase, protease and urease were related to earthworm growth and the stabilization of organic matter. Bacterial DGGE profiles differed between the period of degradation of labile substrates and the maturation step. Fungal communities at the stage of maximum earthworm biomass differed most, suggesting a gut passage effect. The end product was chemically stable and enriched in nutrients, demonstrating that tomato-fruit wastes can be successfully vermicomposted into a valuable soil amendment. We suggest continuous-feeding vermicomposting as an environmentally sound management option for greenhouse wastes. PMID:20675115

Fernández-Gómez, Manuel J; Nogales, Rogelio; Insam, Heribert; Romero, Esperanza; Goberna, Marta

2010-08-02

141

Cadmium accumulation retard activity of functional components of photo assimilation and growth of rice cultivars amended with vermicompost.  

PubMed

Cadmium (Cd) uptake mediated alterations in functional components of photo assimilation during conversion of cow dung and poultry cast to vermicompost were studied in two Indian rice cultivars; MO 16 and MTU 7029. It was found that higher amount of Cd accumulate in plants grown in soil amended with vermicompost which in turn damaged functional components in photo assimilation. Enhancement of root growth was recognized as reason for Cd accumulation. Metabolic alterations noticed among plants were not taken place during application of raw materials used for vermicomposting such as cow dung and poultry cast amendment. Rice varieties accumulated Cd differentially where MTU 7029 accumulated more Cd compare to MO 16. It was also noticed that existence of negative correlation between zinc status of the plant and Cd accumulation. PMID:23819289

Sebastian, Abin; Prasad, M N V

2013-01-01

142

Chemolytic and solid-state spectroscopic evaluation of organic matter transformation during vermicomposting of sugar industry wastes.  

PubMed

The molecular structure of humic acid (HA) extracted was investigated by FT-IR and (13)C CP/MAS NMR spectroscopy during the vermicomposting of sugar industry wastes, viz. pressmud, trash and bagasse for 60days. A rapid decrease in C/N and lignocellulosic (lignin, cellulose, hemicellulose) content was observed in vermicompost during early phase of the process. The FT-IR and (13)C CP/MAS NMR spectra of HA indicated a high rate of change in structure with increase in the alkyl C/O-alkyl C ratio during the process. Aromatic structures and carboxyl groups showed an initial increase but decreased after approximately 40days indicating extensive mineralization during final stages of vermicomposting. PMID:17157000

Sen, Biswarup; Chandra, T S

2006-12-06

143

Biological and chemical reactivity and phosphorus forms of buffalo manure compost, vermicompost and their mixture with biochar.  

PubMed

This study characterized the carbon and phosphorus composition of buffalo manure, its compost and vermicompost and investigated if presence of bamboo biochar has an effect on their chemical and biological reactivity. The four substrates were characterized for chemical and biochemical composition and P forms. The biological stability of the four substrates and their mixtures were determined during an incubation experiment. Their chemical reactivity was analyzed after acid dichromate oxidation. Biological reactivity of these substrates was related to their soluble organic matter content, which decreased in the order buffalo manure>compost>vermicompost. Phosphorus was labile in all organic substrates and composting transformed organic P into plant available P. The presence of biochar led to a protection of organic matter against chemical oxidation and changed their susceptibility to biological degradation, suggesting that biochar could increase the carbon sequestration potential of compost, vermicompost and manure, when applied in mixture. PMID:24071441

Ngo, Phuong-Thi; Rumpel, Cornelia; Ngo, Quoc-Anh; Alexis, Marie; Vargas, Gabriela Velásquez; Mora Gil, Maria de la Luz; Dang, Dinh-Kim; Jouquet, Pascal

2013-08-28

144

Influence of cow manure vermicompost on the growth, metabolite contents, and antioxidant activities of Chinese cabbage ( Brassica campestris ssp. chinensis )  

Microsoft Academic Search

The effects of cow manure vermicompost on plant growth, metabolite contents, and antioxidant activities of Chinese cabbage\\u000a were investigated in pot cultures. Five treatments were designed by mixing vermicompost and soil at ratio of 0:7, 1:7, 2:7,\\u000a 4:7, 7:0 (w\\/w). Marketable weight of Chinese cabbage was significantly (p?

Donghong Wang; Qinghua Shi; Xiufeng Wang; Min Wei; Jinyu Hu; Jun Liu; Fengjuan Yang

2010-01-01

145

Technology for efficient and successful delivery of vermicompost colonized bioinoculants in Pogostemon cablin (patchouli) Benth.  

PubMed

The usefulness of vermicompost as a supporting media for growth of bioinoculants was evaluated for successful transfer of sufficient propagules of bioinoculants into the organic fields. The rooted plants after 50 days were pot and field tested for their growth and yield performances when transplanted along with rooting medium into pots/organic fields. The rooting medium, 50 days of inoculation, contained sufficient population of bioinoculants and arbuscular mycorrhizal (AM) fungi. Treatment with bioinoculants (except Trichoderma harzianum) substantially improved the root and shoot biomass of nursery raised rooted cuttings particularly in treatments containing Azotobacter chroococcum (150 and 91.67%, respectively), Glomus intraradices (117 and 91.67%, respectively) and Pseudomonas fluorescens (117 and 83%, respectively). The transplanted rooted plants in pots, over two harvests, yielded higher shoot biomass when rooting medium contained A. chroococcum (147%), G. intraradices (139%) and P. fluorescencs (139%). Although the treatments did not affect the content of essential oil, the quality of essential oil as measured by the content of patchouli alcohol improved with Glomus aggregatum (18%). Similar trends were observed in field trials with significantly higher biomass yield achieved with A. chroococcum (51%), G. intraradices (46%) and P. fluorescencs (17%) compared to control (un-inoculated) plots. Increased in herb yield was found to be related with increased nutrient uptake. The population of bioinoculants in the rhizosphere was observed to be considerably higher in plots receiving vermicompost enriched with bioinoculants. This technology can be a successful way of delivering sufficient propagules of bioinoculants along with vermicompost especially in organic fields. PMID:22806808

Singh, Rakshapal; Divya, S; Awasthi, Ashutosh; Kalra, Alok

2011-06-28

146

Composting and vermicomposting experiences in the treatment and bioconversion of asphaltens from the Prestige oil spill.  

PubMed

This work illustrates the effectiveness of composting and vermicomposting in degrading fuel-in-water emulsions from oil spills (chapapote), and the isolation of potentially useful microorganisms for its biodegradation. Firstly, an alternative to the biodegradation of asphaltens from the Prestige oil spill (still present in some chapapote rafts in the Cantabrian coast) by means of the application of composting techniques to a microbial partnership acclimated to fuel-oil is offered. Our aim is that, after a relatively short period of time, the microorganisms can obtain its source of carbon and energy from asphaltens. The addition of metabolic co-substrates, like cow bed and potato peelings, allows the fragmentation of complex compounds into smaller structures, susceptible to further degradation. Afterwards, a maturation of the compost by means of a treatment with earthworms (Eisenia foetida) is necessary. Thus, through the vermicomposting it will be possible to obtain a valued product, useful in the processes of ground amendment, with little presence of asphaltens and occluded polycyclic aromatic hydrocarbons, rich in humus, and with an important bacterial flora of Bacillus genera, so that it can be typical of co-activators and accelerating products in composting processes. Along with this article, we show some parameters that control the evolution of the compost products (evolved gases, acidity, temperature and humidity); the chemical and microbiological analytical results; and the germination assays of vermicomposting. Results reveal that by using microorganisms living in either earthworm intestines (Stenotrophomonas maltophilia) or vermiculture substrates (Scedosporium apiospermium), it is possible to degrade and to eliminate the polycyclic asphaltens into CO(2) and H(2)O, helped by evaporation, dissolution and/or photo-oxidation processes. The obtained end product has contents of interesting vegetal nutrients and, mainly, it displays very high germination indices. PMID:17512195

Martín-Gil, Jesús; Navas-Gracia, Luís Manuel; Gómez-Sobrino, Ernesto; Correa-Guimaraes, Adriana; Hernández-Navarro, Salvador; Sánchez-Báscones, Mercedes; del Carmen Ramos-Sánchez, María

2007-05-23

147

Cloning and functional characterization of endo-?-1,4-glucanase gene from metagenomic library of vermicompost.  

PubMed

In the vermicomposting of paper mill sludge, the activity of earthworms is very dependent on dietetic polysaccharides including cellulose as energy sources. Most of these polymers are degraded by the host microbiota and considered potentially important source for cellulolytic enzymes. In the present study, a metagenomic library was constructed from vermicompost (VC) prepared with paper mill sludge and dairy sludge (fresh sludge, FS) and functionally screened for cellulolytic activities. Eighteen cellulase expressing clones were isolated from about 89,000 fosmid clones libraries. A short fragment library was constructed from the most active positive clone (cMGL504) and one open reading frame (ORF) of 1,092 bp encoding an endo-?-1,4-glucanase was indentified which showed 88% similarity with Cellvibrio mixtus cellulase A gene. The endo-?-1,4-glucanase cmgl504 gene was overexpressed in Escherichia coli. The purified recombinant cmgl504 cellulase displayed activities at a broad range of temperature (25-55°C) and pH (5.5-8.5). The enzyme degraded carboxymethyl cellulose (CMC) with 15.4 U, while having low activity against avicel. No detectable activity was found for xylan and laminarin. The enzyme activity was stimulated by potassium chloride. The deduced protein and three-dimensional structure of metagenome-derived cellulase cmgl504 possessed all features, including general architecture, signature motifs, and N-terminal signal peptide, followed by the catalytic domain of cellulase belonging to glycosyl hydrolase family 5 (GHF5). The cellulases cloned in this work may play important roles in the degradation of celluloses in vermicomposting process and could be exploited for industrial application in future. PMID:23812813

Yasir, Muhammad; Khan, Haji; Azam, Syed Sikander; Telke, Amar; Kim, Seon Won; Chung, Young Ryun

2013-06-28

148

Management of fresh water weeds (macrophytes) by vermicomposting using Eisenia fetida.  

PubMed

In the present study, potential of Eisenia fetida to recycle the different types of fresh water weeds (macrophytes) used as substrate in different reactors (Azolla pinnata reactor, Trapa natans reactor, Ceratophyllum demersum reactor, free-floating macrophytes mixture reactor, and submerged macrophytes mixture reactor) during 2 months experiment is investigated. E. fetida showed significant variation in number and weight among the reactors and during the different fortnights (P <0.05) with maximum in A. pinnata reactor (number 343.3?±?10.23 %; weight 98.62?±?4.23 % ) and minimum in submerged macrophytes mixture reactor (number 105?±?5.77 %; weight 41.07?±?3.97 % ). ANOVA showed significant variation in cocoon production (F4?=?15.67, P <0.05) and mean body weight (F4?=?13.49, P <0.05) among different reactors whereas growth rate (F3?=?23.62, P <0.05) and relative growth rate (F3?=?4.91, P <0.05) exhibited significant variation during different fortnights. Reactors showed significant variation (P <0.05) in pH, Electrical conductivity (EC), Organic carbon (OC), Organic nitrogen (ON), and C/N ratio during different fortnights with increase in pH, EC, N, and K whereas decrease in OC and C/N ratio. Hierarchical cluster analysis grouped five substrates (weeds) into three clusters-poor vermicompost substrates, moderate vermicompost substrate, and excellent vermicompost substrate. Two principal components (PCs) have been identified by factor analysis with a cumulative variance of 90.43 %. PC1 accounts for 47.17 % of the total variance represents "reproduction factor" and PC2 explaining 43.26 % variance representing "growth factor." Thus, the nature of macrophyte affects the growth and reproduction pattern of E. fetida among the different reactors, further the addition of A. pinnata in other macrophytes reactors can improve their recycling by E. fetida. PMID:23589265

Najar, Ishtiyaq Ahmed; Khan, Anisa B

2013-04-16

149

Dynamics of biological and chemical parameters during vermicomposting of solid textile mill sludge mixed with cow dung and agricultural residues  

Microsoft Academic Search

In India, thousands of tons of textile mill sludge are produced every year. We studied the ability of epigeic earthworm Eisenia foetida to transform textile mill sludge mixed with cow dung and\\/or agricultural residues into value added product, i.e., vermicompost. The growth, maturation, mortality, cocoon production, hatching success and the number of hatchlings were monitored in a range of different

Priya Kaushik; V. K. Garg

2004-01-01

150

Vermicomposting of coffee pulp using the earthworm Eisenia fetida : Effects on C and N contents and the availability of nutrients  

Microsoft Academic Search

In Colombia, more than 1 million tons of coffee pulp are produced every year. Its transformation into compost by means of turned piles has led to a final product with poor physical and chemical characteristics and vermicomposting has been suggested as an alternative method of transforming these wastes into a useful organic fertilizer. The ability of the earthworm Eisenia fetida

F. H. Orozco; J. Cegarra; L. M. Trujillo; A. Roig

1996-01-01

151

Vermicomposting of vegetable-market solid waste using Eisenia fetida: Impact of bulking material on earthworm growth and decomposition rate  

Microsoft Academic Search

Vegetable-market solid waste is produced in millions of tones in urban areas and creates a problem of safe disposal. The aim of this study was to convert vegetable solid waste (VW) amended with wheat straw (WS), cow dung (CD), and biogas slurry (BGS) into vermicompost using earthworm Eisenia fetida. VW was mixed in bulky materials (WS, CD, and BGS) in

Surindra Suthar

2009-01-01

152

Vermicomposting of coffee pulp using the earthworm Eisenia fetida: Effects on C and N contents and the availability of nutrients  

Microsoft Academic Search

In Colombia, more than 1 million tons of coffee pulp are produced every year. Its transformation into compost by means of turned piles has led to a final product with poor physical and chemical characteristics and vermicomposting has been suggested as an alternative method of transforming these wastes into a useful organic fertilizer. The ability of the earthworm Eisenia fetidato

F. H. Orozco; J. Cegarra; L. M. Trujillo; A. Roig

1996-01-01

153

Dynamic changes in bacterial community structure and in naphthalene dioxygenase expression in vermicompost-amended PAH-contaminated soils  

Microsoft Academic Search

The aim of the present study was to explore the potential for using vermicompost from olive-mill waste as an organic amendment for enhanced bioremediation of polycyclic aromatic hydrocarbons (PAHs)-contaminated soils. The focus was to analyse the genetic potential and the naphthalene dioxygenase (NDO) expression of the bacterial communities involved in the degradation of naphthalene, as chemical model for the degradation

Patrizia Di Gennaro; Beatriz Moreno; Emanuele Annoni; Sonia García-Rodríguez; Giuseppina Bestetti; Emilio Benitez

2009-01-01

154

Potential of filter-vermicomposter for household wastewater pre-treatment and sludge sanitisation on site.  

PubMed

Septic tank systems have been widely used to separate and digest solid matter in the household wastewater for a long time. However, they contaminate groundwater with pathogens and nutrients and deprive agriculture of valuable nutrients and soil conditioner from human excreta. Compared with septic tank systems the filter-composter (Rottebehaelter), which usually consists of an underground monolithic concrete tank having two filter beds at its bottom or two filter bags that are hung side by side and used alternately at intervals of 6-12 months, is an efficient component for solid-liquid separation, pre-treatment and collection/storage of solid matter in household wastewater. The solids are retained and decompose in the filter bags or on the filter bed while the liquid filters through. However, because of the high moisture content of the retained solids decomposition is slow. Therefore, secondary treatment of the retained solids is required for sanitisation. The breakthrough was the combination of vermicomposting with the filter-composter system. Relatively dry and stable retained materials were obtained in the filter bags in about 3 months only. No secondary treatment is required as the human excreta will be converted to vermicastings, which are hygienically safe and can be reused as soil conditioner. Therefore, further development of the filter-composter with vermicomposting is worthwhile, especially the aspects of sanitisation of the faecal matter and its reuse as a soil conditioner. PMID:17506421

Gajurel, D; Deegener, S; Shalabi, M; Otterpohl, R

2007-01-01

155

Changes in microbial community structure and function during vermicomposting of pig slurry.  

PubMed

Most studies investigating the effects of earthworms on microorganisms have focused on the changes before and after vermicomposting rather than those that occur throughout the process. In the present study, we designed continuous feeding reactors in which new layers of pig slurry (1.5 and 3 kg) were added sequentially to form an age gradient inside the reactors in order to evaluate the impact of the earthworm species Eisenia fetida on microbial community structure and function. The activity of earthworms greatly reduced the bacterial and fungal biomass and microbial diversity relative to the control values. However, the pronounced presence of earthworms in the younger layers stimulated microbial activity and as such increased carbon mineralization probably due to the fact that the microorganisms may have been less resource-limited as a result of earthworm activity, as indicated by the ratio of monounsaturated to saturated PLFAs. PMID:21220200

Gómez-Brandón, María; Aira, Manuel; Lores, Marta; Domínguez, Jorge

2010-12-22

156

[Comparative studies on vermicomposting of sewage sludge with two epigeic earthworms].  

PubMed

A comparative study was conducted two epigeic species earthworms (Bimastus parvus and Eisenia foetida) for the evaluation of their efficacy in vermicomposting of sewage sludge. The various changes studied during pot experiments were the physiochemical properties of the sewage sludge, sludge reduction and earthworm biomass. Vermicomposting resulted that both epigeic species earthworms showed same capability among sewage sludge mineralization and decomposition rate and reduction. By the end of experiment, the pH value declined to 6.27 with B. parvus and 7.07 with E. foetida, but both epigeic species earthworms showed same mineralization and decomposition rate. B. parvus produced 31.96%, 5.76% and 17.91% increases in nitrogen, phosphorus, and potassium as well as 44.14% and 30.69% decreases in C/N and C/P ratios as compared to initial after 30 days of inoculation. In contrast, E. foetida produced 35.48% and 11.58% increases in nitrogen and potassium as well as 10.12%, 46.73% and 20.50% decreases in phosphorus, C/N and C/P ratios as compared to initial after 30 days of earthworm activity. At the same time, both epigeic species earthworms resulted in significant reduction in heavy metal content. The reduction in heavy metal content for B. parvus and E. foetida was found in the order: Zn > Cu > Pb > Cr and Cu > Zn > Ph > Cr. At the end of experiment, the weight and cocoons of B. parvus and E. foetida showed significant increase, which the growth rate and the reproductive rate were 76%-86% and 156%-131% respectively. PMID:20623864

Chen, Xue-min; Huang, Kui; Fu, Xiao-yong; Ni, Shao-ren

2010-05-01

157

Kinetic parameters of dehydrogenase in the assessment of the response of soil to vermicompost and inorganic fertilisers  

Microsoft Academic Search

Kinetic parameters (V\\u000a max and K\\u000a m) of dehydrogenase activity were determined in order to assess the metabolic response of a soil about 1?year after organic\\u000a and mineral treatments. The soil was planted with maize (Zea mays) and treated with the following fertilisers: organic (vermicompost; VC), mineral (ammonium phosphate and urea), and an organo-mineral\\u000a mixture. V\\u000a max, which represents a

G. Masciandaro; B. Ceccanti; V. Ronchi; C. Bauer

2000-01-01

158

Compositional and functional features of humic acid-like fractions from vermicomposting of sewage sludge and cow dung  

Microsoft Academic Search

The chemical changes occurring in five different substrates of sewage sludge spiked with different proportions of cow dung after vermicomposting with Eisenia foetida for 90 days were investigated. Their humic acid-like (HAL) fractions were isolated to determine the elemental and functional composition, and structural and functional characteristics using ultraviolet\\/visible, Fourier transform infrared (FT-IR) and fluorescence spectroscopies and scanning electron microscopy.

Xiaowei Li; Meiyan Xing; Jian Yang; Zhidong Huang

2011-01-01

159

Vermicomposting of sludges from paper mill and dairy industries with Eisenia andrei: A pilot-scale study  

Microsoft Academic Search

We studied vermicomposting with Eisenia andrei of sludges from a paper mill mixed with cattle manure in a six-month pilot-scale experiment. Initially, a small-scale laboratory experiment was carried out to determine the growth and reproduction rates of earthworms in the different substrates tested. In the pilot-scale experiment, the number of earthworms increased between 22- and 36-fold and total biomass increased

C. Elvira; L. Sampedro; E. Benítez; R. Nogales

1998-01-01

160

Vermicomposting of herbal pharmaceutical industry waste: earthworm growth, plant-available nutrient and microbial quality of end materials.  

PubMed

Efforts were made to decompose herbal pharmaceutical industrial waste (HPIW) spiked with cow dung (CD) using Eisenia fetida. A total of five vermibeds: T(1) - HPIW (0%+CD 100%, control), T(2) - HPIW (25%), T(3) - HPIW (50%), T(4) - HPIW (75%) and T(5) - HPIW (100%) were used for vermicomposting. The changes in biology and chemistry of vermibeds were measured after ten days interval. E. fetida showed high growth and cocoon production rate in all vermibeds. The vermicomposted material contained great population of fungi 6.0-40.6 (CFU × 10(5)g(-1)), bacteria 220-1276.0 (CFU × 10(8)g(-1)) and actinomycetes 410.0-2962.0 (CFU × 10(5)g(-1)) than initial material. Vermicomposted material was rich in plant-available forms of nutrients (N-NO(3)(-),PO(4)(3-),available K and SO(4)(-2)). Results suggested that noxious industrial waste can be converted into valuable product for sustainable soil fertility programme. PMID:22440575

Singh, Deepika; Suthar, Surindra

2012-03-04

161

Stabilisation of sewage sludge and vinasse bio-wastes by vermicomposting with rabbit manure using Eisenia fetida.  

PubMed

Changes in the chemical characteristics and biological parameters of Eisenia fetida were assessed by VER using (CO+VE) rabbit manure (Vo) spiked with sewage sludge (SS) or vinasse (V). Seven mixtures were used: Vo, control; Vo+SS at 10%, 30%, and 50% (SS1, SS2, and SS3); Vo+V at 10%, 30%, and 50% (V1, V2, and V3). SS vermicomposts had higher humus, nutrient and total metal contents, but less soluble salts (EC) than V vermicomposts. The number and weight of worms were higher in Vo, followed by SS, at decreasing doses. V3 showed the smallest number and size. The EC of the initial mixtures explained reduced weight, whereas EC and avP2O5 accounted for lower numbers. Vermicomposting is an efficient biowaste recycling technology, but the total amount and composition of soluble salts in food influence the quality of end products and are of primary importance for biological parameters of worms. PMID:23584410

Molina, María José; Soriano, María Desamparados; Ingelmo, Florencio; Llinares, Josep

2013-03-16

162

Effect of vermicomposting on calcium, sulphur and some heavy metal content of different biodegradable organic wastes under liming and microbial inoculation.  

PubMed

A study was conducted to evaluate the changes in total calcium and sulphur and some heavy metal (Zn, Cu, and Pb) concentration of different organic wastes affected by liming and microorganism inoculation. Vermicomposting was an effective technology for disposal of organic substrates like municipal solid wastes (MSW), possessing comparatively higher concentration of heavy metals. The addition of lime in initial organic substrates significantly (P ? 0.05) increased total calcium and total sulphur content of vermicomposts. Inoculation of microorganisms significantly (P ? 0.05) reduced the heavy metal content of final products as compared to control. Fungal strains were comparatively more effective in detoxification of heavy metals than B. polymyxa. PMID:22375592

Das, Debabrata; Bhattacharyya, Pradip; Ghosh, B C; Banik, Pabitra

2012-01-01

163

Evaluation of vermicompost as a raw natural adsorbent for adsorption of pesticide methylparathion.  

PubMed

The assessment of vermicompost (VC) as a low-cost and alternative adsorbent for the removal of the pesticide methylparathion (MP) from an aqueous medium has been investigated by batch and column experiments. Parameters related to MP adsorption, i.e. equilibrium time (61.5 min) and adsorption pH (6.8) were optimized by using Doehlert design. The initial and final MP concentrations after adsorption assays were determined by square-wave adsorptive cathodic stripping voltammetry using an electrode composed of a multiwalled carbon nanotube dispersed in mineral oil. Batch adsorption experimental data were fitted to the Langmuir and Freundlich isotherm adsorptions, and a very good fit to the Langmuir linear model, giving a maximum adsorption capacity (MAC) of 0.17 mg g(-1). This result was very similar to that obtained with the column experiments. In order to evaluate the MP desorption from column packed VC, 100.0 ml of nitric acid solution (pH 3.0) has been percolated through material. No leaching of MP was observed, thus confirming the strong interaction between MP and VC. The satisfactory MAC obtained and low cost makes the VC a reliable natural material for the removal of MP from aqueous effluents. PMID:22519100

Mendes, Camila Bitencourt; Lima, Giovana de Fátima; Alves, Vanessa Nunes; Coelho, Nívia Maria Melo; Dragunski, Douglas Cardoso; Tarley, César Ricardo Teixeira

164

Substrate-induced respiration as a measure of microbial biomass in vermicomposting studies.  

PubMed

Here it is evaluated the relationship between substrate-induced respiration (SIR) and microbial biomass C (C(mic), estimated by chloroform fumigation-extraction) in order to establish SIR as a quick technique to determine microbial biomass in vermicomposting processes. For this, there were designed continuous feeding reactors in which new layers of manure were added sequentially to form an age gradient inside the reactors. Six reactors were set up with and without earthworms (three reactors per treatment). In reactors, with and without earthworms, values of C(mic) and SIR ranged from 1690 to 42,900 microg g(-1)dw and from 43 to 2300 microg CO(2) h(-1)g(-1)dw, respectively. SIR was significantly related to C(mic) (r=0.63, P<0.0001). It is proposed an equation to convert SIR values into C(mic), SIR (microg CO(2) h(-1)g(-1)dw)=25.97+0.04 C(mic) (microg g(-1)dw) which will be useful for comparison between studies which used different techniques for determining microbial biomass. PMID:20400302

Aira, Manuel; Domínguez, Jorge

2010-04-18

165

Vermicomposting of tannery sludge mixed with cattle dung into valuable manure using earthworm Eisenia fetida (Savigny).  

PubMed

The present study revealed the role of earthworm in converting tannery sludge into a valuable product. Tannery sludge was toxic to earthworm, therefore it was mixed with cattle dung in different proportions viz. 0:100 (T(0)), 10:90 (T(10)), 25:75 (T(25)), 50:50 (T(50)) and 75:25 (T(75)) on dry weight basis. The minimum mortality and highest population buildup of worms was in T(0) mixture. Nitrogen, sodium, phosphorus and pH increased from initial in the range of 7.3-66.6%, 16.90-70.58%, 8.57-44.8% and 2.8-13.65%, respectively. On the other hand potassium, organic carbon and electrical conductivity decreased in the range of 4.34-28.5%, 7.54-22.35% and 32.35-53.12%, respectively. C:N ratio decreased from 20.53% to 47.36% in the final products. Transition metals increased significantly from the initial value and within the permissible limit. The result indicated that vermicomposting with Eisenia fetida is better for changing this sludge into nutrient rich manure in a short period of time. PMID:21676611

Vig, Adarsh Pal; Singh, Jaswinder; Wani, Shahid Hussain; Singh Dhaliwal, Salwinder

2011-05-27

166

Bioactivity of chemically transformed humic matter from vermicompost on plant root growth.  

PubMed

Chemical reactions (hydrolysis, oxidation, reduction, methylation, alkyl compounds detachment) were applied to modify the structure of humic substances (HS) isolated from vermicompost. Structural and conformational changes of these humic derivatives were assessed by elemental analyses, size exclusion chromatography (HPSEC), solid-state nuclear magnetic resonance ((13)C CPMAS-NMR), and diffusion ordered spectroscopy (DOSY-NMR), whereas their bioactivity was evaluated by changes in root architecture and proton pump activation of tomato and maize. All humic derivatives exhibited a large bioactivity compared to original HS, both KMnO(4)-oxidized and methylated materials being the most effective. Whereas no general relationship was found between bioactivity and humic molecular sizes, the hydrophobicity index was significantly related with proton pump stimulation. It is suggested that the hydrophobic domain can preserve bioactive molecules such as auxins in the humic matter. In contact with root-exuded organic acids the hydrophobic weak forces could be disrupted, releasing bioactive compounds from humic aggregates. These findings were further supported by the fact that HS and all derivatives used in this study activated the auxin synthetic reporter DR5::GUS. PMID:20232906

Dobbss, Leonardo Barros; Pasqualoto Canellas, Luciano; Lopes Olivares, Fábio; Oliveira Aguiar, Natália; Peres, Lázaro Eustáquio Pereira; Azevedo, Mariana; Spaccini, Riccardo; Piccolo, Alessandro; Façanha, Arnoldo R

2010-03-24

167

Solid waste management of temple floral offerings by vermicomposting using Eisenia fetida.  

PubMed

Recycling of temple waste (TW) mainly comprising of floral offerings was done through vermitechnology using Eisenia fetida and its impact on seed germination and plant growth parameters was studied by comparing with kitchen waste (KW) and farmyard waste (FYW) vermicompost (VC). The worm biomass was found to be maximum in TW VC compared to KW and FYW VCs at both 40 and 120days old VCs. Physico-chemical analysis of worm-worked substrates showed better results in TW VC especially in terms of electrical conductivity, C/N, C/P and TK. 10% TW VC-water extract (VCE) showed stimulatory effect on germination percentage of chickpea seeds while KW and FYW VCE proved effective at higher concentration. Variation in growth parameters was also observed with change in the VC-soil ratio and TW VC showed enhanced shoot length, root length, number of secondary roots and total biomass at 12.5% VC compared to KW and FYW VC. PMID:23481343

Singh, Akanksha; Jain, Akansha; Sarma, Birinchi K; Abhilash, P C; Singh, Harikesh B

2013-03-06

168

Plasmid transfer between introduced and indigenous bacteria in leaf litter, soil and vermicompost as affected by soil invertebrates  

Microsoft Academic Search

Plasmid transfer between introduced strains of Pseudomonas stutzeri JM302 (pLV1013), Pseudomonas putida PAW340 (pLV1017), Pseudomonas aeruginosa PAO5 (RP4), and Enterobacter cloacae MF10 (RP4), all of them harbouring genetically modified or naturally occurring plasmids and bacteria indigenous to oak leaf\\u000a litter, soddy-podzolic soil or vermicompost was monitored using non-sterile laboratory microcosms inhabited by the millipede\\u000a Pachyiulus flavipes, the woodlouse Armadillidium vulgare,

B. A. Byzov; H. Claus; E. B. Tretyakova; N. F. Ryabchenko; I. N. Mozgovaya; D. G. Zvyagintsev; Z. Filip

1999-01-01

169

Vermicomposting of toxic weed--Lantana camara biomass: chemical and microbial properties changes and assessment of toxicity of end product using seed bioassay.  

PubMed

This work illustrates the results of vermicomposting trials of noxious weed - Lantana camara (LL) leaf litter spiked with cow dung (CD) in different ratios (0%, 20%, 40%, 60% and 80%) using Eisenia fetida. A total of five treatments were established and changes in chemical and microbial properties of vermibeds have been observed for 60 days. In all treatments, a decrease in pH (19.5-30.7%), total organic carbon (TOC) (12-23%) and C:N ratio (25-35%), but increase in ash content (16-40%), total N(N(tot)) (11-32%), available phosphorous (P(avail)) (445-629%), exchangeable potassium (K(exch)) (63-156%) exchangeable calcium (Ca(exch)) (67-94%),and N-NO3(-) (164-499%) was recorded. Vermibeds with 40-60% LL (T2 and T3) showed better mineralization rate. The number of fungi, bacteria and actinomycetes showed 0.33-1.67-fold, 0.72-2.33-fold and 2.03-2.99-fold increase, respectively after vermicomposting process. The germination index (GI) was between 47% and 83% in all vermicomposts as indicated by seed bioassay test. Results thus suggested that Lantana may be a potential source for vermicompost production for sustainable agriculture. PMID:23796668

Suthar, Surindra; Sharma, Priyanka

2013-06-22

170

Organic matter transformations in lignocellulosic waste products composted or vermicomposted ( eisenia fetida andrei): Chemical analysis and 13C CPMAS NMR spectroscopy  

Microsoft Academic Search

Lignocellulosic wastes (of maple) were composted and vermicomposted for 10 months under controlled conditions. Chemical and 13C CPMAS NMR spectroscopic analyses were made to characterize the transformations of the organic matter. At first, the total organic matter and carbon mass underwent a relatively rapid decrease. There was a concomitant decomposition of polysaccharides including cellulose. The degradation of aromatic structures and

M. Vinceslas-Akpa; M. Loquet

1997-01-01

171

Direct and Residual Effect of Vermicompost, Biofertilizers and Phosphorus on Soil Nutrient Dynamics and Productivity of Chickpea-Fodder Maize Sequence  

Microsoft Academic Search

Field experiments were carried out at the Indian Agricultural Research Institute, New Delhi, India. The principal findings revealed that application of 3t vermicompost\\/ha to chickpea improved dry matter accumulation, grain yield and grain protein content in chickpea, soil N and P and bacterial count, dry fodder yield of succeeding maize, total N and P uptake by the cropping system over

R. S. Jat; I. P. S. Ahlawat

2006-01-01

172

Chemical composition and bioactivity properties of size-fractions separated from a vermicompost humic acid.  

PubMed

Preparative high performance size-exclusion chromatography (HPSEC) was applied to humic acids (HA) extracted from vermicompost in order to separate humic matter of different molecular dimension and evaluate the relationship between chemical properties of size-fractions (SF) and their effects on plant root growth. Molecular dimensions of components in humic SF was further achieved by diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR) based on diffusion coefficients (D), while carbon distribution was evaluated by solid state (CP/MAS) (13)C NMR. Seedlings of maize and Arabidopsis were treated with different concentrations of SF to evaluate root growth. Six different SF were obtained and their carbohydrate-like content and alkyl chain length decreased with decreasing molecular size. Progressive reduction of aromatic carbon was also observed with decreasing molecular size of separated fractions. Diffusion-ordered spectroscopy (DOSY) spectra showed that SF were composed of complex mixtures of aliphatic, aromatic and carbohydrates constituents that could be separated on the basis of their diffusion. All SF promoted root growth in Arabidopsis and maize seedlings but the effects differed according to molecular size and plant species. In Arabidopsis seedlings, the bulk HA and its SF revealed a classical large auxin-like exogenous response, i.e.: shortened the principal root axis and induced lateral roots, while the effects in maize corresponded to low auxin-like levels, as suggested by enhanced principal axis length and induction of lateral roots. The reduction of humic heterogeneity obtained in HPSEC separated size-fractions suggested that their physiological influence on root growth and architecture was less an effect of their size than their content of specific bioactive molecules. However, these molecules may be dynamically released from humic superstructures and exert their bioactivity when weaker is the humic conformational stability as that obtained in the separated size-fractions. PMID:19910019

Canellas, Luciano P; Piccolo, Alessandro; Dobbss, Leonardo B; Spaccini, Riccardo; Olivares, Fábio L; Zandonadi, Daniel B; Façanha, Arnoldo R

2009-11-11

173

Experimental co-digestion of corn stalk and vermicompost to improve biogas production  

SciTech Connect

Anaerobic co-digestion of corn stalk and vermicompost (VC) as well as mono-digestion of corn stalk were investigated. Batch mono-digestion experiments were performed at 35 {+-} 1 {sup o}C and initial total solid loading (TSL) ranged from 1.2% to 6.0%. Batch co-digestion experiments were performed at 35 {+-} 1 {sup o}C and initial TSL of 6% with VC proportions ranged from 20% to 80% of total solid (TS). For mono-digestion of corn stalk, a maximum methane yield of 217.60 {+-} 13.87 mL/g TS{sub added} was obtained at initial TSL of 4.8%, and acidification was found at initial TSL of 6.0% with the lowest pH value of 5.10 on day 4. Co-digestion improved the methane yields by 4.42-58.61% via enhancing volatile fatty acids (VFAs) concentration and pH value compared with mono-digestion of corn stalk. The maximum biogas yield of 410.30 {+-} 11.01 mL/g TS{sub added} and methane yield of 259.35 {+-} 13.85 mL/g TS{sub added} were obtained for 40% VC addition. Structure analysis by X-ray diffractometry (XRD) showed that the lowest crystallinity of 35.04 of digested corn stalk was obtained from co-digestion with 40% VC, which decreased 29.4% compared to 49.6 obtained from un-treated corn stalk. It is concluded that co-digestion with VC is beneficial for improving biodigestibility and methane yield from corn stalk.

Chen Guangyin [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zheng Zheng, E-mail: zzhenghj@fudan.edu.c [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Department of Environmental Science and Engineering, Fudan University, Shanghai 200433 (China); Yang Shiguan [National Engineering Laboratory of Biomass Power Generation Equipment, School of Renewable Energy, North China Electric Power University, Beijing 102206 (China); Fang Caixia; Zou Xingxing; Luo Yan [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

2010-10-15

174

Vacuna frente al virus del papiloma humano y cribado de cáncer de cuello de útero  

Microsoft Academic Search

The HPV vaccine is a primary preventive strategy against cervical cancer. It is highly effective and safe, but its implementation does not preclude the need to maintain a secondary prevention protocol for all vaccinated women.The clinical use of the vaccine will lead to a noticeably lower number of abnormal smear reports, as a result of the vaccine's high efficacy against

Javier Cortés; Eduardo Vilaplana; Pilar Miranda; Gabriel Ferret; Daniel Andía; José Manuel Ramón y Cajal; José Antonio Vidart

2009-01-01

175

Cómo hacer frente al cáncer: cuidados médicos de apoyo y cuidados paliativos  

Cancer.gov

Formas de controlar los efectos físicos y psicológicos del cáncer y del tratamiento en los pacientes y sus familias, así como los efectos en la calidad de vida. También se incluye información sobre servicios de salud, ayuda económica y seguro médico.

176

Variabilidad espacio-temporal de los eufáusidos frente a la costa de Concepción, Chile  

Microsoft Academic Search

RESUMEN. Se analizó la distribución espacio-temporal de los eufáusidos colectados en cuatro cruceros estacionales realizados frente a la costa de Concepción en 1991. Se identificaron ocho especies, Euphausia mucronata, E. vallentini, Nyctiphanes simplex, Nematoscelis megalops, Nematobrachion flexipes, Stylocheiron longicorne, S. affine y S. suhmii. La mayoría de las especies había sido registrada en aguas del Pacífico suroriental, a excepción de

Lorena Linacre; Sergio Palma

2004-01-01

177

Reduction of total coliform numbers during vermicomposting is caused by short-term direct effects of earthworms on microorganisms and depends on the dose of application of pig slurry  

Microsoft Academic Search

During vermicomposting of organic waste, the interactions between epigeic earthworms and the detrital microbial community lead to decreases in the abundance of some potentially pathogenic microorganisms. Despite its importance, little is known about the mechanisms involved and the factors that affect the intensity of this effect. In the present study, we carried out three experiments to test the effect of

Fernando Monroy; Manuel Aira; Jorge Domínguez

2009-01-01

178

CARACTERIZACIÓN QUÍMICA Y FÍSICA DE COMPOST DE LOMBRICES ELABORADOS A PARTIR DE RESIDUOS ORGÁNICOS PUROS Y COMBINADOS1 Vermicompost chemical and physical characterization from raw and mixed organic wastes  

Microsoft Academic Search

The purpose of this experiment was the chemical and physical characterization of some vermicomposts and their most suitable mixture in yield and quality. The experiment design used was complete randomized block with five treatment and five replications: T1 (100% cattle feedlot manure E); T2 (100% kitchen wastes DC); T3 (75% E and 25% DC); T4 (50% E and 50% DC);

Alicia E. Castillo; Silvio H. Quarín; María C. Iglesias

179

RESSIGNIFICAÇÃO DO PAPEL DA ESCOLA ESPECIAL E DO PROFESSOR ESPECIALISTA ITINERANTE FRENTE À INCLUSÃO EDUCACIONAL DA CRIANÇA COM DEFICIÊNCIA INTELECTUAL  

Microsoft Academic Search

RESUMO - Este estudo objetiva repensar a ressignificação do papel da escola especial, frente ao desafio da inclusão educacional de alunos com deficiência intelectual, bem como a relevância da atuação do professor especialista itinerante neste processo. O texto é fundamentado nas experiências da autora como professora regente de sete alunos da Escola Especial de Educação Estimulação e Desenvolvimento - CEDAE

Nádia Aparecida Poleto

180

Vermicomposting toilets, an alternative to latrine style microbial composting toilets, prove far superior in mass reduction, pathogen destruction, compost quality, and operational cost.  

PubMed

Composting toilets aim to recycle excrement into safe, stable humus. Preceding this, low costs, low risks, and mass reduction should be ensured. Source separating vermicomposting toilets (SSVCs) outperformed mixed latrine microbial composting toilets (MLMCs) in all categories. MLMCs: incurred ten times greater operational costs; created 10x more operator exposure; employed no proven pathogen reduction mechanism since solid end-products averaged 71,000±230,000CFU/g (fecal-origin) Escherichia coli and 24±5% total solids, consistently failed NSF/ANSI Standard 41; failed to reduce volatile solids compared to raw fecal matter; increased total contaminated dry mass by 274%, and produced alkaline end-product (8.0±0.7) high in toxic free ammonia (Solvita® 2.6±1.5). SSVCs have low maintenance costs and risks; adequate worm density for pathogen destruction (0.03±0.04g-worm/g-material); reduced E. coli 200±244CFU/g in neutral (7.4±0.3), stable (60±10% volatile solids), and mature (4±0 Solvita® NH(3)) end-product. PMID:22658870

Hill, Geoffrey B; Baldwin, Susan A

2012-06-01

181

ALS Association  

MedlinePLUS

... Read More » 2013 Walk to Defeat ALS® Fall Season Begins It's time to put on your walking ... Us Tweets by @alsassociation In The Spotlight Flu Season . . . and You It’s that time of year again! ...

182

Reduction of total coliform numbers during vermicomposting is caused by short-term direct effects of earthworms on microorganisms and depends on the dose of application of pig slurry.  

PubMed

During vermicomposting of organic waste, the interactions between epigeic earthworms and the detrital microbial community lead to decreases in the abundance of some potentially pathogenic microorganisms. Despite its importance, little is known about the mechanisms involved and the factors that affect the intensity of this effect. In the present study, we carried out three experiments to test the effect of the earthworm Eisenia fetida on total coliform numbers in pig slurry. We firstly applied low and high doses (1.5 and 3 kg, respectively) of pig slurry to small scale vermireactors with and without earthworms. We found that E. fetida significantly reduced total coliform numbers after 2 weeks, but only in the low dose vermireactors. In a subsequent feeding experiment in mesocosms, we observed that the coliform population was reduced by 98% after passage through the earthworms' guts, which suggests that digestive processes in the gut of E. fetida are the main factors involved in the decrease in total coliforms observed in the low dose vermireactors. Decreases in total coliform numbers were not related to decreases in bacterial biomass, which indicates a specific negative effect of earthworms on the coliforms. In the third experiment, we tested the indirect effect of earthworms on total coliforms by inoculating pig slurry with either 2 or 10% vermicompost. The addition of vermicompost did not affect the number of coliforms either after 15, 30 or 60 days, which supports the idea that this bacterial group is more affected by the passage through the gut of E. fetida than by interactions with the earthworm-shaped microbial community. PMID:19640567

Monroy, Fernando; Aira, Manuel; Domínguez, Jorge

2009-07-28

183

Changes in enzymatic activities and microbial properties in vermicompost of water hyacinth as affected by pre-composting and fungal inoculation: a comparative study of ergosterol and chitin for estimating fungal biomass.  

PubMed

In this experiment, three different fungal species, viz. Trichoderma viridae, Aspergillus niger and Phanerochaete chrysosporium, were inoculated in 7 day and 15 day partially decomposed water hyacinth to study their effect on enzymatic activities, microbial respiration and fungal biomass of the final stabilized product. The results suggested that increasing the duration of pre-composting from 7 days to 15 days did not show any significant effect on the activities of hydrolytic enzymes. Inoculation of fungi significantly (P < or = 0.05) increased cellulase, protease and acid and alkaline phosphatase activities. The highest value of ergosterol was recorded in A. niger-inoculated vermicomposts. Inoculation of P. chrysosporium in initial organic waste registered the highest chitin content in vermicompost. A comparison of fungal biomass and chitin content revealed a conversion factor of 2.628 with a standard deviation of 0.318. Due to significant correlation (r = 0.864), this conversion factor allows for the calculation of fungal biomass from chitin, which is comparatively more stable than ergosterol. PMID:20303251

Pramanik, P

2010-03-19

184

AL Amyloidosis  

PubMed Central

Definition of the disease AL amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin (Ig) light chains (LC) (most commonly of lambda isotype) usually secreted by a small plasma cell clone. Most patients have evidence of isolated monoclonal gammopathy or smoldering myeloma, and the occurrence of AL amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. The key event in the development of AL amyloidosis is the change in the secondary or tertiary structure of an abnormal monoclonal LC, which results in instable conformation. This conformational change is responsible for abnormal folding of the LC, rich in ? leaves, which assemble into monomers that stack together to form amyloid fibrils. Epidemiology AL amyloidosis is the most common type of systemic amyloidois in developed countries with an estimated incidence of 9 cases/million inhabitant/year. The average age of diagnosed patients is 65 years and less than 10% of patients are under 50. Clinical description The clinical presentation is protean, because of the wide number of tissues or organs that may be affected. The most common presenting symptoms are asthenia and dyspnoea, which are poorly specific and may account for delayed diagnosis. Renal manifestations are the most frequent, affecting two thirds of patients at presentation. They are characterized by heavy proteinuria, with nephrotic syndrome and impaired renal function in half of the patients. Heart involvement, which is present at diagnosis in more than 50% of patients, leading to restrictive cardiopathy, is the most serious complication and engages prognosis. Diagnostic methods The diagnosis relies on pathological examination of an involved site showing Congo red-positive amyloid deposits, with typical apple-green birefringence under polarized light, that stain positive with an anti-LC antibody by immunohistochemistry and/or immunofluorescence. Due to the systemic nature of the disease, non-invasive biopsies such as abdominal fat aspiration should be considered before taking biopsies from involved organs, in order to reduce the risk of bleeding complications. Differential diagnosis Systemic AL amyloidosis should be distinguished from other diseases related to deposition of monoclonal LC, and from other forms of systemic amyloidosis. When pathological studies have failed to identify the nature of amyloid deposits, genetic studies should be performed to diagnose hereditary amyloidosis. Management Treatment of AL amyloidosis is based on chemotherapy, aimed at controlling the underlying plasma clone that produces amyloidogenic LC. The hematological response should be carefully checked by serial measurements of serum free LC. The association of an alkylating agent with high-dose dexamethasone has proven to be effective in two thirds of patients and is considered as the current reference treatment. New agents used in the treatment of multiple myeloma are under investigation and appear to increase hematological response rates. Symptomatic measures and supportive care is necessary in patients with organ failure. Noticeably, usual treatments for cardiac failure (i.e. calcium inhibitors, ?-blockers, angiotensin converting enzyme inhibitors) are inefficient or even dangerous in patients with amyloid heart disease, that should be managed using diuretics. Amiodarone and pace maker implantation should be considered in patients with rhythm or conduction abnormalities. In selected cases, heart and kidney transplantation may be associated with prolonged patient and graft survival. Prognosis Survival in AL amyloidosis depends on the spectrum of organ involvement (amyloid heart disease being the main prognosis factor), the severity of individual organs involved and haematological response to treatment.

2012-01-01

185

Irán Contemporáneo: De la Monarquía a la República Islámica. Análisis de las luchas sociales y de la alternativa religiosa shi'ita frente al secularismo  

Microsoft Academic Search

An analysis of the political, economic, social and religious history of Irán in the 20lh Century begins with the Pahlavi dynasty and con- tinúes with Iran's Shiite Islamic Revolution, led by the Ayatollah Khumayni, opponent of the Shah and founder of the Islamic Republic of Irán in February, 1979. Khumayni proposed the political, economic and social possibility of religión as

Roberto Marín Guzmán

186

Amyotrophic Lateral Sclerosis (ALS)  

MedlinePLUS

... progressive, invariably fatal neurological disease that attacks the nerve cells (neurons) responsible for controlling voluntary muscles. In ALS, ... Information New gene mutations linked to ALS and nerve cell growth dysfunction Researchers have linked newly discovered gene ...

187

INTRODUCCIÓN AL CONCEPTO DE IDENTIDAD CONSTITUCIONAL Y A SU FUNCIÓN FRENTE AL DERECHO SUPRANACIONAL E INTERNACIONAL DE LOS DERECHOS DE LA PERSONA ? INTRODUCTION TO THE CONCEPT OF CONSTITUTIONAL IDENTITY AND ITS ROLE BEFORE SUPRANATIONAL AND INTERNATIONAL LAW OF HUMAN RIGHTS  

Microsoft Academic Search

The article pretends to explain the concept and function of constitutional identity. The task is fulfilled describing the key features and the role of constitutional identity in the Constitution-making, interpretation and reform, and the relationship between national constitution and non national human rights Law.

Manuel Núñez Poblete

2008-01-01

188

ALS longitudinal kickers  

SciTech Connect

This paper discusses the coupled-bunch instability and how it applies to the ALS accelerator. The longitudinal ALS kicker is part of the bunch-to-bunch feedback system planned to control coupled-bunch instabilities in the ALS. The mechanical features of the kicker are described, and the analytic tools developed to aid in the design are discussed. A method to predict the performance of the kicker in the accelerator from measurements on a prototype are described.

Voelker, F.

1992-10-01

189

Evolution of Al Qaeda.  

National Technical Information Service (NTIS)

Al Qaeda is a significant threat to the national security of the United States and its allies. This makes it important for individuals in these countries, both military and civilian, to understand the evolution of this threat. This thesis analyzes Al Qaed...

S. P. Wilson

2007-01-01

190

What Is ALS?  

MedlinePLUS

... to be involuntary. Remember, though, while you cannot stop your heart, you can hold your breath - so be aware ... trials that hold promise. Importantly, there are significant devices ... ALS ‘burns out,’ stops progressing or progresses at a very slow rate. ...

191

MDA ALS Caregiver's Guide  

MedlinePLUS

... day along the way. Lynne Nieto Corona del Mar, Calif. MDA ALS Division Co-Chair Publications Magazines ... 8 — Finding Caregiving Help Chapter 9 — End-of Life Issues Appendices MDA in Your Community Stay informed. ...

192

Iraq and Al Qaeda.  

National Technical Information Service (NTIS)

In building a case for invading Iraq and ousting Saddam Hussein from power, the Administration asserted that the regime of Saddam Hussein had a working relationship with the Al Qaeda organization. The Administration stated that the relationship dated to t...

K. Katzman

2007-01-01

193

Al-Qaeda  

Microsoft Academic Search

al-Qaeda, referred to as ‘the Base’ was founded in 1989 by Osama bin Laden and other like-thinking militant Muslims as the ultimate outcome of the 1979 invasion\\u000a of Afghanistan by the USSR. Initially, al-Qaeda was created to record and track down the names of the mujahideen listed as missing during the guerrilla war against the USSR.

Anne Rathbone; Charles K. Rowley

194

High temperature oxidation of mechanically alloyed NiAl–Fe–AlN–Al 2O 3  

Microsoft Academic Search

A new NiAl–Fe alloy containing uniformly distributed ultra-fine AlN and Al2O3 dispersoids was produced by mechanical alloying in a controlled atmosphere and by subsequent hot extrusion process. The new NiAl–Fe–AlN–Al2O3 alloy was oxidized in the temperature range between 1073 and 1473 K in air. The alloy displayed similar oxidation behavior with conventional NiAl alloys. As the oxidation temperature increased, the

D. B. Lee; G. Y. Kim; S. W. Park; S. C. Ur

2002-01-01

195

Microstructural characterization and tribocorrosion behaviour of Al\\/Al 3Ti and Al\\/Al 3Zr FGMs  

Microsoft Academic Search

Al\\/Al3Ti and Al\\/Al3Zr functionally graded materials (FGMs) were manufactured through a centrifugal method from Al–5 mass % Ti and Al–5 mass % Zr, respectively. Applied centrifugal forces were 30, 60 and 120 G (units of gravity). Microstructural characterization was performed and the influence of the reinforcing phase on the tribocorrosion behaviour of the FGMs was investigated. An increase in both

S. C. Ferreira; P. D. Sequeira; Yoshimi Watanabe; E. Ariza; L. A. Rocha

2011-01-01

196

Al Qaeda Training Manual  

NSDL National Science Digital Library

The first resource is a US Department of Justice release of portions of an English translation of the Al Qaeda training manual located by police in Manchester, England during a search of an Al Qaeda member's home. The manual was found in a computer file described as "the military series" related to the "Declaration of Jihad." The cover and excerpts from the 12 chapters can be viewed as a .pdf file. Content of the text includes religious commentary, organizational tactics, guidelines for member selection, techniques for spying, and security measures. The DOJ does not provide the entire document because it does not want to encourage terrorism.

2001-01-01

197

ALS superbend magnet system  

SciTech Connect

The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing.

Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

2000-09-15

198

Creep Behavior of Al-Rich Fe-Al Intermetallics.  

National Technical Information Service (NTIS)

The compression creep behavior of two dual-phase intermetallic alloys (FeAl2-Fe2Al5 and FeAl3-Fe2Al5) was investigated over the temperature range 600-1000 deg C. A normal primary creep stage, stress exponent between 4 and 5, and normal creep transient aft...

Y. L. Jeng E. J. Lavernia R. M. Hayes J. Wolfenstine

1995-01-01

199

Al/Al-oxide nanophase composites: Hardness and NMR Results  

NASA Astrophysics Data System (ADS)

Hardness and high temperature 27-Al NMR measurements of Al/Al-oxide nanophase composites produced by consolidation of nanoscale Al particles which have been passivated by exposure to air are reported. The Al/Al-oxide nanophase composite material produced has a low density, is electrically conducting and has a hardness much larger than that of metallic Al. High temperature NMR measurements show that the Al metal melts at the same temperature in all the samples, including a large-grained Al metal sample, independent of grain size and without a change in shape of the sample. The results here confirm previous thermal measurements which show that the Al metal melts without grain growth in these materials. On the other hand, the temperature for the onset of rapid atomic diffusion, as estimated from NMR line widths, shows a significant sample dependence. Heated samples exhibit a further factor of five increase in hardness and yet remain electrically conducting.

Suits, B. H.; Apte, P.

1998-03-01

200

Unraveling Al Qaeda's Strategy.  

National Technical Information Service (NTIS)

Gauging the effectiveness of the U.S. strategy to counter international terrorism requires first an understanding of the objectives, ways and means, and implementation strategy of the adversary. In this case, the adversary is Al Qaeda and its network of a...

D. L. Shaffer

2005-01-01

201

Al Parker: American Illustrator  

NSDL National Science Digital Library

This tribute to Al Parker, the noted magazine illustrator and artist, was fashioned from extensive holdings at the Washington University Library in St. Louis. Known as "The Dean of Illustrators," Al Parker attended school at the St. Louis School of Fine Arts at Washington University and went on to become of the most prolific and important American illustrators of the twentieth century. Parker was best-known for his modernist deployment of line, patterning, and bold, flat colors, which helped shape the general "look" of the period from the 1930s to the 1960s. Using short clips of Parker's original illustrations and drawings, this exhibit offers a glimpse into his work and contributions to the medium. Of particular interest is the section devoted to Parker's famous "Mother-Daughter" covers for the Ladies Home Journal, which began in 1939 and ran for 17 years.

2001-01-01

202

ALS Project Management Manual  

SciTech Connect

This manual has been prepared to help establish a consistent baseline of management practices across all ALS projects. It describes the initial process of planning a project, with a specific focus on the production of a formal project plan. We feel that the primary weakness in ALS project management efforts to date stems from a failure to appreciate the importance of ''up-front'' project planning. In this document, we present a guide (with examples) to preparing the documents necessary to properly plan, monitor, and control a project's activities. While following the manual will certainly not guarantee good project management, failure to address the issues we raise will dramatically reduce the chance of success. Here we define success as meeting the technical goals on schedule and within the prescribed budget.

Krupnick, Jim; Harkins, Joe

2000-05-01

203

Dar Al Islam Mosque  

Microsoft Academic Search

The mosque and school of the Dar Al Islam Foundation stand on a plateau above the Chama Valley, near the settlement of Abiquiu\\u000a to the north of the capital Sante Fe. The buildings and its inhabitants are part of a project that was initiated in the late\\u000a seventies. The project was born out of a Utopian notion of a liberal

Rudolf Stegers

204

Partnerwahl als konsensuelle Entscheidung  

Microsoft Academic Search

Zusammenfassung  Die vorliegende Studie setzt unsere Analysen der Kontaktierungsprozesse im Online-Dating (KZfSS 2\\/2009) fort. Da Paarbeziehungen\\u000a auf einer konsensuellen Entscheidung für eine gemeinsame Beziehung beruhen, widmet sich der vorliegende Beitrag der Frage,\\u000a wie Männer und Frauen auf Erstkontaktversuche reagieren. Die Datenstruktur von Online-Dating-Börsen bietet eine einzigartige\\u000a Chance, soziologisch im Detail zu rekonstruieren, wie Paarbeziehungen als konsensuelle Wahlhandlung nach und nach entstehen.

Florian Schulz; Jan Skopek; Hans-Peter Blossfeld

2010-01-01

205

Abu Musab Al Suri: Architect of the New Al Qaeda  

Microsoft Academic Search

Drawing on new sources, the authors argue that Abu Musab al Suri (real name Mustafa Setmariam Nasar), now in U.S. custody, is the principle architect of Al Qaeda's post–9\\/11 structure and strategy. His vision, which predated 9\\/11, of transforming Al Qaeda from a vulnerable hierarchical organization into a resilient decentralized movement, was largely the formula Al Qaeda adopted after the

Paul Cruickshank; Mohannad Hage Ali

2007-01-01

206

Frequently Asked Questions about ALS and the ALS Registry  

MedlinePLUS

... on clinical trials? Questions About the ALS Registry Why was the registry created? Who created and is responsible for maintaining the ... Back to Top Questions About the ALS Registry Why was the ALS registry created? The registry was created as a tool to ...

207

Plasmonen als Lichttransporter: Nanooptik  

NASA Astrophysics Data System (ADS)

Metallische Nanopartikel, Nanodrähte oder Filme können Licht in Oberflächen-Plasmonen einfangen. Dieses Phänomen spielt sich im optischen Nahfeld und im Subwellenlängenbereich ab. Dabei entsteht ein hybrider, optoelektronischer Anregungszustand aus Licht und oszillierenden Leitungselektronen. Metallische Nanopartikel können zum Beispiel als Hilfsantennen die Fluoreszenz von Biomolekülen erheblich verstärken. Das ist für Fluoreszenzsensoren interessant. Experimente zeigen, dass metallische Nanodrähte in Oberflächen-Plasmonen Licht transportieren können. Auf zweidimensionalen, strukturierten Metallfilmen wurden Bauelemente bis hin zum Interferometer für Plasmonen erfolgreich demonstriert. Das junge Feld der Plasmonik könnte wichtige Beiträge zu einer zukünftigen Nanooptik liefern.

Aussenegg, Franz; Ditlbacher, Harald

2006-09-01

208

Vermicomposting of Winery Wastes: A Laboratory Study  

Microsoft Academic Search

In Mediterranean countries, millions of tons of wastes from viticulture and winery industries are produced every year. This study describes the ability of the earthworm Eisenia andrei to compost different winery wastes (spent grape marc, vinasse biosolids, lees cakes, and vine shoots) into valuable agricultural products. The evolution of earthworm biomass and enzyme activities was tracked for 16 weeks of

ROGELIO NOGALES; CELIA CIFUENTES; EMILIO BENÍTEZ

2005-01-01

209

Sustainable Household Organic Waste Management via Vermicomposting  

Microsoft Academic Search

Increasing waste generation in developing countries has alarmed authorities on waste disposal issues. Therefore, various alternatives have been looked into to reduce waste disposed into landfill. Among others are the bioremediation options which may allow the conversion of putrescible wastes into value added products such as compost, biogas and others. This study was aimed to find optimal experimental set-up to

2009-01-01

210

Doppelthydrophile Blockcopolymere als Mineralisationstemplate  

NASA Astrophysics Data System (ADS)

Die vorliegende Arbeit beschäftigt sich mit der Synthese und den Eigenschaften von doppelthydrophilen Blockcopolymeren und ihrer Anwendung in einem biomimetischen Mineralisationsprozeß von Calciumcarbonat und Bariumsulfat. Doppelthydrophile Blockcopolymere bestehen aus einem hydrophilen Block, der nicht mit Mineralien wechselwirkt und einem zweiten Polyelektrolyt-Block, der stark mit Mineraloberflächen wechselwirkt. Diese Blockcopolymere wurden durch ringöffnende Polymerisation von N-carboxyanhydriden (NCA's) und a-methoxy-?-amino[poly(ethylene glycol)] PEG-NH2 als Initiator hergestellt. Die hergestellten Blockcopolymere wurden als effektive Wachstumsmodifikatoren für die Kristallisation von Calciumcarbonat und Bariumsulfat Mineralien eingesetzt. Die so erhaltenen Mineralpartikel (Kugeln, Hantel, eiförmige Partikel) wurden durch Lichtmikroskopie in Lösung, SEM und TEM charakterisiert. Röntgenweitwinkelstreuung (WAXS) wurde verwendet, um die Modifikation von Calciumcarbonat zu ermitteln und die Größe der Calciumcarbonat- und Bariumsulfat-Nanopartikel zu ermitteln. This work describes the synthesis and characterization of double hydrophilic block copolymers and their use in a biomimetic mineralization process of Calcium Carbonate and Barium Sulfate. Double hydrophilic block copolymers consist of a hydrophilic block that does not interact with minerals and another hydrophilic polyelectrolyte block that strongly interacts with mineral surfaces. These polymers were synthesised via ring opening polymerisation of N-carboxyanhydride (NCA), and the first hydrophilic block a-methoxy-?-amino[poly(ethylene glycol)] PEG-NH2 was used as an initiator. The prepared block copolymers were used as effective crystal growth modifiers to control the crystallization of Calcium Carbonate and Barium Sulfate minerals. The resulting mineral particles (spheres, dumbbells, egg-like particles) were characterised by light microscopy in solution, by SEM, and by TEM. X-Ray scattering measurements (WAXS) were used to prove the modification of Calcium Carbonate particles and to calculate the size of Calcium Carbonate and Barium Sulfate nanoparticles.

Kasparova, Pavla

2002-07-01

211

Detecting frontotemporal dysfunction in ALS: utility of the ALS Cognitive Behavioral Screen (ALS-CBS).  

PubMed

Up to half of patients with ALS develop cognitive impairment during the course of the illness. Despite this, there is no simple tool for screening patients in the clinical setting. This study examines the sensitivity, specificity and accuracy of the ALS Cognitive Behavioral Screen (ALS-CBS). We administered the measure to 112 ALS patients, including 31 who also underwent comprehensive neuropsychological testing. Screen results were validated by determining the accuracy against the full battery. Optimal cut-off scores for predicting the correct diagnosis were determined, and mean scores were compared between patients, controls and different diagnostic groups. The results demonstrated that mean cognitive scores differed between ALS and normal controls (p < 0.0001). The cognitive section differentiated ALS-FTD from other ALS patients with 100% accuracy. Cognitively normal ALS patients could be distinguished from those with any cognitive deficit with 71% specificity and 85% sensitivity. A separate behavioral score was significantly lower in the ALS cohort compared to controls (p < 0.0001) and predicted ALS-FTD with 80% sensitivity and 88% specificity. In conclusion, the ALS-CBS can aid in detecting cognitive and behavioral impairment in a clinical setting, although it does not replace formal diagnostic assessment. Further validation with larger sample sizes will clarify its clinical utility. PMID:20433413

Woolley, Susan C; York, Michele K; Moore, Dan H; Strutt, Adriana M; Murphy, Jennifer; Schulz, Paul E; Katz, Jonathan S

2010-05-01

212

Interfacial reactions and oxidation behavior of Al 2O 3 and Al 2O 3/Al coatings on an orthorhombic Ti 2AlNb alloy  

NASA Astrophysics Data System (ADS)

The uniform and dense Al 2O 3 and Al 2O 3/Al coatings were deposited on an orthorhombic Ti 2AlNb alloy by filtered arc ion plating. The interfacial reactions of the Al 2O 3/Ti 2AlNb and Al 2O 3/Al/Ti 2AlNb specimens after vacuum annealing at 750 °C were studied. In the Al 2O 3/Ti 2AlNb specimens, the Al 2O 3 coating decomposed significantly due to reaction between the Al 2O 3 coating and the O-Ti 2AlNb substrate. In the Al 2O 3/Al/Ti 2AlNb specimens, a ?-TiAl layer and an Nb-rich zone came into being by interdiffusion between the Al layer and the O-Ti 2AlNb substrate. The ?-TiAl layer is chemically compatible with Al 2O 3, with no decomposition of Al 2O 3 being detected. No internal oxidation or oxygen and nitrogen dissolution zone was observed in the O-Ti 2AlNb alloy. The Al 2O 3/Al/Ti 2AlNb specimens exhibited excellent oxidation resistance at 750 °C.

Li, H. Q.; Wang, Q. M.; Gong, J.; Sun, C.

2011-02-01

213

„Leistung“ als Aktion und Präsentation  

Microsoft Academic Search

\\u000a Zusammenfassungen  Die sprachanalytische Untersuchung des Begriffs „Leistung“ führt zu der Konzeption einer „Philosophie der Leistung“ als einer\\u000a Theorienormativer Aussagen über „Leistung“. Handlungen werden anhand bestimmter Kriterien als „Leistungen“ identifiziert; es kommt daher der Präsentation dieser Aktionen\\u000a als „Leistungen“ Bedeutung zu: Eine „Leistung“ besteht immer aus einer „Aktions-“ und einer „Präsentations-Leistung“. Insbesondere\\u000a die „Präsentations-Leistung“ erfüllt eine entscheidende Funktion bei der Konstitution von

Gunter Gebauer

1972-01-01

214

Microstructures and properties of Al 2O 3\\/Al–AlN composites by pressureless infiltration of Al-alloys  

Microsoft Academic Search

Al alloys were infiltrated into Al2O3 preforms in N2 and N2– 2% H2 gas mixture in the temperature regime of 900–1200°C. The kinetics of nitridation during infiltration were continuously monitored by recording weight gained during infiltration of the preform. The weight gains that are attributed to the formation of AlN in the matrix were observed to increase with processing temperature.

N Nagendra; B. S Rao; V Jayaram

1999-01-01

215

THE ADOLESCENT FEELINGS RELATED TO THE BULLYING PHENOMENA: POSSIBILITIES TO THE NURSING ASSISTANCE IN THIS CONTEXT SENTIMIENTOS DEL ADOLESCENT FRENTE AL FENÓMENO BULLYING: POSSIBILIDADES PARA LA ASISTENCIA DE ENFERMERIA EN ESE CONTEXTO  

Microsoft Academic Search

Bullying is a devastating phenomenon that can affect the adolescent's self-esteem and mental health. Generally occurs in school environment when the adolescent is more susceptible or vulnerable to verbal or moral aggressions that cause to them anguish and pain, meaning as a status of social exclusion. Most of time, health problems as anorexia, bulimia, depression, anxiety and also the suicide,

Agnes Schutz de Oliveira; Priscila da Silva Antonio

216

LA CONTRIBUCION DE LA ENFERMERIA FRENTE AL FENOMENO DE LAS DROGAS Y LA VIOLENCIA EN AMERICA LATINA: UN PROCESO DE CONSTRUCCION NURSING CONTRIBUTION TO DRUGS PHENOMENON AND VIOLENCE IN LATIN AMERICA; A PROCESS  

Microsoft Academic Search

The phenomenon of drugs and violence is a complex issue aggravated by the globalization process, which facilitates the marketing of drugs, money laundering, and increased demand for drugs among different population groups. As a consequence, violence has increased and there have been changes in family structure, lifestyles, and values in all Latin American countries. Few studies have been done on

MARIA DA GLORIA; MIOTTO WRIGHT

2003-01-01

217

Al Qaeda's Scorecard: A Progress Report on Al Qaeda's Objectives  

Microsoft Academic Search

Terrorism scholars are divided over whether terrorism is an effective tactic. Disagreement derives from the fact that the objectives of terrorist groups are often highly contested. Nowhere is this clearer than in contemporary statements on Al Qaeda. This article explores the most common interpretations for why Al Qaeda attacked the United States on 11 September 2001, and then analyzes their

Max Abrahms

2006-01-01

218

AL Amyloidosis with Renal Involvement  

Microsoft Academic Search

Primary (AL amyloidosis) is a systemic disease characterized by an amyloid deposition process in many organs, with unsatisfactory survival of patients. The monoclonal light chains form the fibrils that deposit and accumulate in tissues. Renal involvement is very frequent in AL amyloidosis and could lead to development of nephrotic syndrome followed by the renal failure in many cases. Classic therapeutic

Romana Ryšavá

2007-01-01

219

AlN Substrate Applications.  

National Technical Information Service (NTIS)

The types of presently available AlN substrates are outlined along with the precautions to be taken in using them. Also discussed in detail are the factors to be considered in planning the introduction of AlN substrates and the structures, properties and ...

N. Iwase

1988-01-01

220

Al Qaeda: Ideology and action  

Microsoft Academic Search

Serious threats to global order are said to emanate from Al Qaeda, exemplified by bombings and multiple deaths in, inter alia, Bali, Dar es Salaam, Istanbul, Nairobi, New York and Madrid. These outrages raise the question about the ideological assumptions and goals of Al Qaeda – given that the majority of the dead were not Jews or Christians, but Muslims. What

JEFFREY HAYNES

2005-01-01

221

How al Qaeda lost Iraq  

Microsoft Academic Search

Al Qaeda in Iraq (AQI) has suffered a grave setback in the context of its ongoing campaign there. Since late 2006 Sunni tribal militias working in conjunction with Coalition forces have decimated AQI's ranks, and the organisation has been largely expelled from its former sanctuaries in western Iraq. This article seeks to explain the causes of al Qaeda's defeat with

Andrew Phillips

2009-01-01

222

The Advanced Launch System (ALS)  

NASA Astrophysics Data System (ADS)

The Advanced Launch System (ALS) is an unmanned vehicle that will achieve low hardware cost by using a reusable booster stage which flies back to the launch site, and a core stage in which the rocket engines and redundant avionics are in a module that is returned to earth and recovered for reuse. The booster's utilization of liquid propellant instead of solid propellant will help lower the consumable costs. The ALS also includes launch processing and flight control facilities, necessary support equipment, and ground- and flight-operations infrastructure. The ALS program studies show that, through the ALS, the United States can launch a major Mars initiative economically and with confidence. It is estimated that the objective ALS can be operational in the late 1990s.

Eldred, Charles H.

223

Stimulated emission in AlGaN/AlGaN quantum wells with different Al content  

NASA Astrophysics Data System (ADS)

Stimulated emission (SE) is studied in AlGaN/AlGaN multiple quantum wells (MQWs) with different Al content grown on sapphire substrate. The spectra of spontaneous and stimulated emission and their transformations with increasing temperature as well as stimulated emission thresholds were measured in the temperature range from 8 to 300 K. Phonon-assisted band broadening in low-Al-content MQWs and double-scaled potential profile in high-Al-content MQWs were observed in the samples and linked with carrier localization conditions. The temperature dependence of the stimulated emission threshold was similar in the samples where the stimulated transitions occur between extended states and in the samples where the transitions occur in localized states. The stimulated emission threshold depends predominantly on the density of nonradiative recombination centers.

Mickevi?ius, J.; Jurkevi?ius, J.; Kazlauskas, K.; Žukauskas, A.; Tamulaitis, G.; Shur, M. S.; Shatalov, M.; Yang, J.; Gaska, R.

2012-02-01

224

Al Cu Texture Enhancement by Underlayer Texture  

Microsoft Academic Search

Al Cu layered films and interconnections (Al\\/underlayers) were fabricated and investigatedto observe the effects of underlayer texture on Al texture development and of Al texture onelectromigration resistance. Al(111) texture was enhanced by controlling Ti and TiNunderlayer textures. Values of full width at half maximum for Al(111) rocking curves rangedfrom 0.64° to 4.7° for Al Cu films grown on Ti, TiN\\/Ti,

Tsutomu Sasaki; Hitoshi Dohnomae

1998-01-01

225

Comparing the Thermodynamic Behaviour of Al(1)+ZrO2(s) to Al(1)+Al2O3(s).  

National Technical Information Service (NTIS)

In an effort to better determine the thermodynamic properties of Al(g) and Al2O(g). the vapor in equilibrium with Al(l)+ZrO2(s) was compared to the vapor in equilibrium with Al(l)+Al2O3(s) over temperature range 1197-to-1509K. The comparison was made dire...

E. Copland

2004-01-01

226

Genetic inroads in familial ALS.  

PubMed

Amyotrophic lateral sclerosis (ALS) is a common neurodegenerative disease causing cell death of motor neurons and progressive muscle weakness. The disease is familial in ten percent of cases, of which one-fifth are due to mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1). Two papers in this issue of Nature Genetics describe homozygous mutations in a new gene on chromosome 2q33 in 4 families of Arabian origin with a rare form of juvenile onset ALS (ALS2). The predicted protein structure has domains homologous to GTPase regulatory proteins, and both the types of mutation and the pattern of inheritance suggest that motor neuron degeneration is the result of a loss of function. Further work will determine the relevance of this breakthrough to other, more common forms of ALS. PMID:11586285

Shaw, P J

2001-10-01

227

Transcranial magnetic stimulation in ALS  

PubMed Central

Objective: To investigate transcranial magnetic stimulation (TMS) measures as clinical correlates and longitudinal markers of amyotrophic lateral sclerosis (ALS). Methods: We prospectively studied 60 patients with ALS subtypes (sporadic ALS, familial ALS, progressive muscular atrophy, and primary lateral sclerosis) using single pulse TMS, recording from abductor digiti minimi (ADM) and tibialis anterior (TA) muscles. We evaluated three measures: 1) TMS motor response threshold to the ADM, 2) central motor conduction time (CMCT), and 3) motor evoked potential amplitude (correcting for peripheral changes). Patients were evaluated at baseline, compared with controls, and followed every 3 months for up to six visits. Changes were analyzed using generalized estimation equations to test linear trends with time. Results: TMS threshold, CMCT, and TMS amplitude correlated (p < 0.05) with clinical upper motor neuron (UMN) signs at baseline and were different (p < 0.05) from normal controls in at least one response. Seventy-eight percent of patients with UMN (41/52) and 50% (4/8) of patients without clinical UMN signs had prolonged CMCT. All three measures revealed significant deterioration over time: TMS amplitude showed the greatest change, decreasing 8% per month; threshold increased 1.8% per month; and CMCT increased by 0.9% per month. Conclusions: Transcranial magnetic stimulation (TMS) findings, particularly TMS amplitude, can objectively discriminate corticospinal tract involvement in amyotrophic lateral sclerosis (ALS) from controls and assess the progression of ALS. While central motor conduction time and response threshold worsen by less than 2% per month, TMS amplitude decrease averages 8% per month, and may be a useful objective marker of disease progression. GLOSSARY ADM = abductor digiti minimi; ALS = amyotrophic lateral sclerosis; ANOVA = analysis of variance; CI = confidence interval; CMAP = compound motor action potential; CMCT = central motor conduction time; DTR = deep tendon stretch reflex; fALS = familial ALS; GEE = generalized estimation equations; LMN = lower motor neuron; MEP = motor evoked potential; PLS = primary lateral sclerosis; PMA = progressive muscular atrophy; sALS = sporadic ALS; TA = tibialis anterior; TMS = transcranial magnetic stimulation; UMN = upper motor neuron.

Floyd, A G.; Yu, Q P.; Piboolnurak, P; Tang, M X.; Fang, Y; Smith, W A.; Yim, J; Rowland, L P.; Mitsumoto, H; Pullman, S L.

2009-01-01

228

MADINAT AL-ZAHRAí: INVESTIGACI\\  

Microsoft Academic Search

The virtual reconstruction of the archeological site of Mad inat al-Zahraí in CÛrdoba (Spain) has permitted a new approach to the study and comprehension of this palatine city as well as to the typologies of Islamic architecture in Al-Andalus during the 10th century. Starting from fieldwork and from a photogrammetric survey of the site, the digital model has become a

Antonio Almagro Gorbea; Ana Almagro Vidal

229

Befähigungsgerechtigkeit als Ermöglichung gesellschaftlicher Inklusion  

Microsoft Academic Search

Soziale Gerechtigkeit gilt vielen — vor allem in Deutschland — noch immer als ein zuhöchst attraktiver Wert politischen Zusammenlebens,\\u000a der auch als gesellschaftliche Norm zu etablieren sei. Nicht nur in der politischen Rhetorik, sondern auch in der Sozialtheorie\\u000a und politischen Philosophie schillert der Begriff vielfach. Er ringt vor dem anthropologisch nicht zu bestreitenden Spannungsverhältnis\\u000a von Kooperationswilligkeit und Konkurrenz- und Konfliktbeladenheit

Peter Dabrock

230

Befähigungsgerechtigkeit als Ermöglichung gesellschaftlicher Inklusion  

Microsoft Academic Search

Soziale Gerechtigkeit gilt vielen – vor allem in Deutschland – noch immer als ein zuhöchst attraktiver Wert politischen Zusammenlebens,\\u000a der auch als gesellschaftliche Norm zu etablieren sei. Nicht nur in der politischen Rhetorik, sondern auch in der Sozialtheorie\\u000a und politischen Philosophie schillert der Begriff vielfach. Er ringt vor dem anthropologisch nicht zu bestreitenden Spannungsverhältnis\\u000a von Kooperationswilligkeit und Konkurrenz- und Konfliktbeladenheit

Peter Dabrock

231

FTD and ALS: genetic ties that bind.  

PubMed

Curiously, amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), seemingly disparate neurodegenerative disorders, can be inherited together. Two groups (DeJesus-Hernandez et al. and Renton et al.) show that the long sought after ALS/FTD mutation on chromosomal region 9p is a hexanucleotide expansion in C90RF72. These studies, plus a study on X-linked ALS/FTD, provide molecular starting points for identifying pathways that link ALS and FTD pathogenesis. PMID:22017980

Orr, Harry T

2011-10-20

232

AL1-dependent repression of transcription enhances expression of Tomato golden mosaic virus AL2 and AL3  

PubMed Central

Studies using Nicotiana benthamiana protoplasts have determined that repression of upstream transcription by AL1 protein enhances AL2 and AL3 expression in Tomato golden mosaic virus (TGMV). Mutations resulting in the inability of TGMV AL1 protein to associate with its cognate binding site, result in a decrease in both AL2 and AL3 expression. Reduced expression correlates with an increase in transcription from the AL62 start site, and decreased transcription from downstream initiation sites (AL1935 and AL1629) present within the AL1 coding region. The results demonstrate that, in a tobacco protoplast system, repression of AL62 transcription, regulated through binding of AL1 protein to sequences in the origin of replication, is required prior to AL2 and AL3 gene expression from the AL1935 and AL1629 viral transcripts. This provides a mechanism to regulate expression of AL2, which is involved in suppression of host defense responses and is required for late gene expression.

Shung, Chia-Yi; Sunter, Garry

2010-01-01

233

Muqtada al-Sadr: How to Demilitarize al-Sadr.  

National Technical Information Service (NTIS)

Muqtada al-Sadr has been one of the most influential individuals in Iraq since the U.S. invasion in March 2003. His Mahdi Army has actively confronted coalition forces and engaged in ethnic cleansing that has resulted in the displacement of thousands of I...

M. E. Hollinger

2009-01-01

234

Powder Metallurgy Processing of Dual Phase Al Rich Fe-Al Intermetallics.  

National Technical Information Service (NTIS)

A powder metallurgy technique was used to fabricate two different dual-phase Al-rich Fe-Al intermetallics, namely, FeAl2-Fe2Al5 and FeAl3-Fe2Al5. Powders were first produced by inert gas atomization, and then subsequently consolidated by hot pressing at 1...

Y. L. Jeng R. Hayes J. Wolfenstine E. J. Lavernia

1995-01-01

235

Triple A syndrome mimicking ALS.  

PubMed

We report a 22-year-old female who presented with distal muscular atrophy and weakness in all limbs for two years. Reflexes were symmetrically brisk and electrodiagnostic studies were consistent with upper and lower motor neuron involvement. A diagnosis of juvenile ALS was considered. However, surgery for achalasia in childhood and identification of alacrima and adrenal insufficiency suggested Triple A syndrome accompanied by neurological symptoms. Sequencing of the AAAS gene identified compound heterozygous mutations confirming the clinical diagnosis and demonstrating that Triple A syndrome can mimic juvenile ALS. PMID:18615337

Strauss, Maria; Koehler, Katrin; Krumbholz, Manuela; Huebner, Angela; Zierz, Stephan; Deschauer, Marcus

2008-10-01

236

Andalusian astronomy: al-Zij al-Muqtabis of Ibn al-Kammâd.  

NASA Astrophysics Data System (ADS)

In the twelfth century the Arabic astronomer Ibn al-Kammâd, living in Islamic Spain, composed three sets of astronomical tables, called "zijes". The zijes were largely based on the work of predecessors, going back to Ptolemy on the one hand, and Hindu astronomers on the other. None of his zijes survived in the original Arabic, but a Latin manuscript contains a translation of an apparently complete zij, the "al-Zij al-Muqtabis". This paper examines the body of astronomical knowledge contained in this zij. Specifically, it is shown that one can gain valuable information on the solar theory of the Islamic astronomers from this translation. Furthermore, the theory of lunar and solar eclipses in the work is analyzed, and tables of mean planetary and solar motions are discussed. In addition, tables for the motion of the vernal equinox, star tables, and several topics of Islamic spherical astronomy are examined.

Chabás, J.; Goldstein, B. R.

1994-12-01

237

Glutamate Receptor Aptamers and ALS.  

National Technical Information Service (NTIS)

Excitotoxicity is one of the leading causes for amyotrophic lateral sclerosis (ALS). Our goal was to develop a novel class of powerful aptamer- based, anti-excitotoxic inhibitors against GluR2Qflip, a key AMPA receptor subunit that controls the calcium pe...

L. Niu

2009-01-01

238

Glutamate Receptor Aptamers and ALS.  

National Technical Information Service (NTIS)

Excitotoxicity is one of the leading causes for amyotrophic lateral sclerosis (ALS). Our goal was to develop a novel class of powerful aptamer- based anti-excitotoxic inhibitors against GluR2Qflip a key AMPA receptor subunit that controls the calcium perm...

L. Niu

2008-01-01

239

Interview with Mumna Al Banchaabouchi  

NSDL National Science Digital Library

An interview with Dr Mumna Al Banchaabouchi, researcher in the Mouse Phenotyping Core at EMBL in Monterotondo Italy. This video is two minutes and 55 seconds in length, and available in Quicktime (25 MB) and Windows Media Player (29 MB). All Stem Cells videos are located at: http://www.hhmi.org/biointeractive/stemcells/video.html.

Howard Hughes Medical Institute (Howard Hughes Medical Institute;)

2007-03-31

240

Al Qaeda: A Different Diagnosis  

Microsoft Academic Search

When doubt and confusion reign, when things are--or look--complicated, one should revert to fundamental questions. What is Al Qaeda? This is the question addressed by this article. But as a first step, and in a broader perspective, the real danger in the world today is defined.?

XAVIER RAUFER

2003-01-01

241

Dry sliding wear behaviour of Al–12Si and Al–12Si–3Cu cast alloys  

Microsoft Academic Search

This paper attempts to investigate the influence of the microstructural changes on the dry sliding wear behaviour of Al–12Si and Al–12Si–3Cu cast alloys by grain refinement (Al–1Ti–3B), modification (Al–10Sr) and combined action of both (Al–1Ti–3B+Al–10Sr). Results indicate that combined grain refined and modified Al–12Si–3Cu cast alloys have microstructures consisting of uniformly distributed ?-Al grains, eutectic Al–silicon and fine CuAl2 particles

K. G. Basavakumar; P. G. Mukunda; M. Chakraborty

2009-01-01

242

Molecular Dynamics Study of Velocity Dependence of Sliding Friction at Al/Al and Al2O3/Al2O3 Interface  

NASA Astrophysics Data System (ADS)

Using the newly developed reactive force field, the static and kinetic friction behavior of Al/Al (flat and rough), Al2O3/Al2O3 (commensurate and incommensurate) interfaces have been studied by molecular dynamics simulations. It is found that the commensurate Al2O3/Al2O3 interface has higher friction than incommensurate Al2O3/Al2O3 interface. For both interfaces, at lower velocities, friction exhibits dry friction, whereas above a critical speed, the velocity dependence follows a viscous relation. For Al/Al flat interface, only viscous friction is observed. Roughness on the surface would increase friction and change velocity dependence. The simulation results indicate that the different behaviors of velocity dependence are from the interfacial interaction or potential surface for these friction samples. The origin of static friction is also discussed.

Zhang, Qing; Cagin, Tahir; Goddard, William A.; Qi, Yue; Hector, Louis G.

2004-03-01

243

Identification of Candida albicans ALS2 and ALS4 and Localization of Als Proteins to the Fungal Cell Surface  

PubMed Central

Additional genes in the growing ALS family of Candida albicans were isolated by PCR screening of a genomic fosmid library with primers designed from the consensus tandem-repeat sequence of ALS1. This procedure yielded fosmids encoding ALS2 and ALS4. ALS2 and ALS4 conformed to the three-domain structure of ALS genes, which consists of a central domain of tandemly repeated copies of a 108-bp motif, an upstream domain of highly conserved sequences, and a domain of divergent sequences 3? of the tandem repeats. Alignment of five predicted Als protein sequences indicated conservation of N- and C-terminal hydrophobic regions which have the hallmarks of secretory signal sequences and glycosylphosphatidylinositol addition sites, respectively. Heterologous expression of an N-terminal fragment of Als1p in Saccharomyces cerevisiae demonstrated function of the putative signal sequence with cleavage following Ala17. This signal sequence cleavage site was conserved in the four other Als proteins analyzed, suggesting identical processing of each protein. Primary-structure features of the five Als proteins suggested a cell-surface localization, which was confirmed by indirect immunofluorescence with an anti-Als antiserum. Staining was observed on mother yeasts and germ tubes, although the intensity of staining on the mother yeast decreased with elongation of the germ tube. Similar to other ALS genes, ALS2 and ALS4 were differentially regulated. ALS4 expression was correlated with the growth phase of the culture; ALS2 expression was not observed under many different in vitro growth conditions. The data presented here demonstrate that ALS genes encode cell-surface proteins and support the conclusion that the size and number of Als proteins on the C. albicans cell surface vary with strain and growth conditions.

Hoyer, L. L.; Payne, T. L.; Hecht, J. E.

1998-01-01

244

Thermal conductance of a pressed Al-Al contact  

NASA Astrophysics Data System (ADS)

Thermal conductance of a screw-fastened joint between two blocks of Al-alloys has been measured. An AlMg4.5Mn-block, the end of which is cooled by liquid helium, constitutes the upper part of the sample and the contact is formed at the face surface of a cylindrical extension of that block onto which a cylinder, made of AlMgSi1, is pressed by means of a copper-nickel screw. Pressing of the contact was carried out at room temperature by applying a defined torque, M, to the fastening screw. Three samples of the same shape but with differently treated surfaces of contact (machined flat, electro-chemically polished, with gold plated contacts) were studied. The results showed that the machined flat surfaces yield the best contact and that the contact conductance (measured in the range 4.2 K to 1.8 K) of all samples increased with increasing torque. In addition to thermal measurements, a study of the electrical conductance would be very interesting to determine the different contributions of phonon and electron heat conduction by means of the Wiedemann-Franz law. The work is useful for the GIRL (German Infra-Red Laboratory) space experiment.

Wanner, M.

1981-01-01

245

Dissimilar metal joining of aluminum alloy to galvanized steel with Al–Si, Al–Cu, Al–Si–Cu and Zn–Al filler wires  

Microsoft Academic Search

Aluminum alloy sheets were lap joined to galvanized steel sheets by gas tungsten arc welding (GTAW) with Al–5% Si, Al–12% Si, Al–6% Cu, Al–10% Si–4% Cu and Zn–15% Al filler wires. Different amounts of Si, Cu and Zn were introduced into the weld through different filler wires. The effects of alloying elements on the microstructure in the weld and tensile

Honggang Dong; Wenjin Hu; Yuping Duan; Xudong Wang; Chuang Dong

246

The effect of Si in Al-alloy on electromigration performance in Al filled vias  

NASA Astrophysics Data System (ADS)

Electromigration performance of vias filled with Al-Si-Cu alloys on Ti glue layers was investigated in comparison with W-stud vias. In Al-Si-Cu filled vias, voids were formed at only a few locations in the test structure, while voids were formed at every via in W-stud via chains. It is supposed that Al moves through the Al-Si-Cu via during electromigration in spite of the existence of a glue layer at the via bottom. This phenomenon was observed only in the vias filled with Al-Si-Cu alloy. Al movement was prohibited in Al-Cu filled vias. In Al-Si-Cu filled vias, an Al-Ti-Si alloy was formed at the via bottom while Al3Ti was formed at Al-Cu filled vias. Al is speculated to move through this Al-Ti-Si alloy during electromigration.

Kageyama, Makiko; Hashimoto, Keiichi; Onoda, Hiroshi

1998-01-01

247

Growth processes in molecular beam expitaxy of single-crystal Al layers on AlAs  

Microsoft Academic Search

The molecular beam epitaxial growth processes of Al single-crystal layers deposited at room temperature on As-stabilized and on Al-stabilized AlAs surfaces are investigated insitu using reflection high-energy electron diffraction (RHEED). The epitaxy relationship of Al with the underlying AlAs is (011)[100]Al\\/\\/(001)[110]AlAs irrespective of the surface stoichiometry of AlAs. Detailed RHEED investigation suggests that the initially deposited two one-monolayer-thick Al layers

Hiroaki Nakahara; Hirofumi Matuhata; Yasumasa Okada; Tateki Kurosu; Masamori Iida; Takafumi Yao

1991-01-01

248

Ion beam mixing in the Al\\/NixAl1 - x\\/Ni system  

Microsoft Academic Search

Thin-film alloy samples of Al\\/NixAl1?x\\/Ni (x=0.75, 0.5, 0.25) were irradiated at room temperature and at 160 °C with 280 and 560 keV Xe ions to a dose of 1.1×1016 Xe ions\\/cm2. The samples were analyzed by Rutherford backscattering spectrometry. In the Al\\/Ni3Al\\/Ni configuration the Ni3Al layer mixes more strongly with Al than with Ni. In the Al\\/NiAl\\/Ni samples, the NiAl

E. Rimini; M. Nastasi; J. Liu; J. C. Barbour; J.-P. Hirvonen; J. W. Mayer

1986-01-01

249

First-principles calculations on Al/AlB 2 interfaces  

NASA Astrophysics Data System (ADS)

The AlB 2 (1 1 1) surfaces and Al (1 1 1)/AlB 2 (0 0 0 1) interface were studied by first-principles calculations to clarify the heterogeneous nucleation potential of ?-Al grains on AlB 2 particles in purity aluminium and hypoeutectic Al-Si alloys. It is demonstrated that the AlB 2 (0 0 0 1) surface models with more than nine atomic layers exhibit bulk-like interior, wherein the interlayer relaxations localized within the top three layers are well converged. The outmost layer of AlB 2 free surface having a preference of metal atom termination is evidenced by surface energy calculations. With Al atoms continuing the natural stacking sequence of bulk AlB 2, Al-Al metallic bonds are formed across interface during the combination of Al atoms with Al-terminated AlB 2 surface. The calculated interfacial energy of the Al/AlB 2 interface is much larger than that between the ?-Al and aluminium melts, elucidating the poor nucleation potency of ?-Al grains on AlB 2 particles from thermodynamic considerations.

Han, Y. F.; Dai, Y. B.; Wang, J.; Shu, D.; Sun, B. D.

2011-06-01

250

Photoemission study of Al adlayers on Mn  

NASA Astrophysics Data System (ADS)

Al overlayers on Mn, studied by photoemission spectroscopy, show a large lowering of the Al 2p core-level binding energy by 0.5 eV at submonolayer (0.1 ML) coverage. The binding energy increases with coverage and reaches the bulk Al value at ?1.3 ML. The Al 2p core-level spectrum exhibits extra components related to the different chemical environment at the interface, which decrease in intensity with increasing Al coverage. The Al related plasmon loss features appear above 1 ML. The present results are explained by a strong Al s,p-Mn 3d hybridization at the submonolayer coverage due to interface alloying, whose influence on the spectra is dominated by metallic bonding in the Al layer as coverage increases. The valence-band spectra demonstrate systematic suppression of Mn 3d-like states and emergence of a parabolic free-electron-like Al density of states.

Dhaka, R. S.; Shukla, A. K.; Horn, K.; Barman, S. R.

2011-12-01

251

Synthesis of AlN/Al Polycrystals along with Al Nanoparticles Using Thermal Plasma Route  

SciTech Connect

This paper for the first time reports the (200) oriented growth of hexagonal Aluminum nitride crystals during synthesis of aluminum nanoparticles in dc transferred arc thermal plasma reactor by gas phase condensation in nitrogen plasma. The structural and morphological study of as synthesized AlN crystal and aluminium nanoparticles was done by using the x-ray diffraction method, scanning electron microscopy and transmission electron microscopy.

Kanhe, Nilesh S.; Nawale, A. B.; Kulkarni, N. V.; Bhoraskar, S. V.; Mathe, V. L. [Department of Physics, University of Pune, Pune 411007 (India); Das, A. K. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India)

2011-07-15

252

The strengthening effect of Al 3Ti in high temperature deformation of Al–Al 3Ti composites  

Microsoft Academic Search

A series of Al–Al3Ti composites with systematic variation of Al3Ti content were prepared by mechanical alloying. Microstructural observations have indicated that among these composites, the only distinct variable is the Al3Ti content, while the other microstructural variables are essentially the same. The high temperature (623–773K) deformation behavior of these composites was found to be similar to that of dispersion-hardened aluminum.

S. H. Wang; P. W. Kao

1998-01-01

253

Processing of In-Situ Al-AlN Metal Matrix Composites via Direct Nitridation Method.  

National Technical Information Service (NTIS)

The primary objective of this research was to provide a fundamental understanding of the processing science necessary to fabricate the Aluminum Nitride (AlN) reinforced Aluminum (Al) composites via direct nitration of the Al alloy melt. From the thermodyn...

K. S. Shin Y. S. Kim N. J. Kim

1998-01-01

254

Investigation of Wear Anisotropy in a Severely Deformed Al-Al3Ti Composite  

NASA Astrophysics Data System (ADS)

In the current investigation, Al-Al3Ti composite was processed by equal channel angular pressing (ECAP). ECAP was carried out using routes A and BC up to eight passes of deformation. It was observed that increasing the number of ECAP passes causes fragmentation of Al3Ti platelet particles and decreases their sizes compared to their original sizes in the undeformed Al-Al3Ti specimens. Moreover, the microstructure of route A-ECAPed Al-Al3Ti composite samples showed a strong alignment of the fragmented Al3Ti particles parallel to the pressing axis. On the other hand, ECAPed Al-Al3Ti alloy specimens by route BC have a relatively homogeneous distribution of Al3Ti particles. Because of the platelet Al3Ti particle fragmentation by ECAP, all the ECAPed specimens showed small anisotropy in their wear property in spite of this observed anisotropic microstructure induced by route A-ECAP.

El-Hadad, Shimaa; Sato, Hisashi; Watanabe, Yoshimi

2012-05-01

255

The preparation and mechanical properties of Al 2O 3\\/Ni 3Al composites  

Microsoft Academic Search

Al2O3\\/Ni3Al composites containing 10vol% of intermetallic phase have been studied in this work. Ni3Al particles with two different morphologies were added to the alumina matrix, viz. Ni3Al as-prepared (AP) by atomization and Ni3Al finely ball-milled (BM) in argon for 96h. Both AP and BM composites were prepared by pressureless sintering at a relatively low temperature. As-prepared Ni3Al powder was also

Vincenzo M Sglavo; Francesco Marino; Bing-Rong Zhang

1999-01-01

256

Effects of the Al content on pore structures of porous TieAl alloys  

SciTech Connect

Porous TieAl alloys with different nominal compositions were fabricated through a reactive synthesis of Ti and Al elemental powders. It has been found that the pore parameters vary with the Al contents, indicating that the nature of the pores can be manipulated through changing the Al contents. In addition, detailed structural characterizations showed that the fabricated porous TieAl alloys can have three crystalline phases (i.e., a2-Ti3Al, g-TiAl, and TiAl3) when using different compositions. The fundamental reasons behind these phenomena have been explored.

Jaing, Y [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; He, Y H [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; Xu, N P [Membrane Science and Technology Research Center, Nanjing University of Technology, Nanjing 210009, C; Zou, J [School of Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, QLD; Huang, B [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; Lui, C T [Oak Ridge National Laboratory (ORNL)

2008-01-01

257

Phosphorus Enhances Al Resistance in Al-resistant Lespedeza bicolor but not in Al-sensitive L. cuneata Under Relatively High Al Stress  

PubMed Central

Background and Aims Aluminium (Al) toxicity and phosphorus (P) deficiency often co-exist in acidic soils and limit crop production worldwide. Lespedeza bicolor is a leguminous forage species that grows very well in infertile, acidic soils. The objective of this study was to investigate the effects of Al and P interactions on growth of Lespedeza and the distributions of Al and P in two different Al-resistant species, and to explore whether P can ameliorate the toxic effect of Al in the two species. Methods Two species, Lespedeza bicolor and L. cuneata, were grown for 30 d with alternate Al and P treatments in a hydroponics system. Harvested roots were examined using a root-system scanner, and the contents of Al, P and other nutrient elements in the plants were determined using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Haematoxylin staining was used to observe the distribution of Al in the roots of seedlings. After pre-culture with or without P application, organic acids in the exudates of roots exposed to Al were held in an anion-exchange resin, eluted with 2 m HCl and then analysed using high-performance liquid chromatography (HPLC). Key Results Lespedeza bicolor exhibited a stronger Al resistance than did L. cuneata; Al exclusion mechanisms may mainly be responsible for resistance. P application alleviated the toxic effect of Al on root growth in L. bicolor, while no obvious effects were observed in L. cuneata. Much less Al was accumulated in roots of L. bicolor than in L. cuneata after P application, and the P contents in both roots and shoots increased much more for L. bicolor than for L. cuneata. Lespedeza bicolor showed a higher P/Al ratio in roots and shoots than did L. cuneata. P application decreased the Al accumulation in root tips of L. bicolor but not in L. cuneata. The amount of Al-induced organic acid (citrate and malate) exudation from roots pre-cultured with P was much less than from roots without P application; no malate and citrate exudation was detected in L. cuneata. Conclusions P enhanced Al resistance in the Al-resistant L. bicolor species but not in the Al-sensitive L. cuneata under relatively high Al stress, although P in L. cuneata might also possess an alleviative potential. Enhancement of Al resistance by P in the resistant species might be associated with its more efficient P accumulation and translocation to shoots and greater Al exclusion from root tips after P application, but not with an increased exudation of organic acids from roots.

Sun, Qing Bin; Shen, Ren Fang; Zhao, Xue Qiang; Chen, Rong Fu; Dong, Xiao Ying

2008-01-01

258

Nonstoichiometry of Al-Zr intermetallic phases.  

National Technical Information Service (NTIS)

Nonstoichiometry of metastable cubic (beta)(prime) and equilibrium tetragonal (beta) Al-Zr intermetallic phases of the nominal composition Al(sub 3)Zr in Al-rich alloys has been extensively studied. It is proposed that the ''dark contrast'' of (beta)(prim...

V. Radmilovic G. Thomas

1994-01-01

259

Rethinking ALS: The FUS about TDP43  

Microsoft Academic Search

Amyotrophic lateral sclerosis (ALS) is an adult-onset neuro- degenerative disorder in which premature loss of motor neu- rons leads to fatal paralysis with a typical disease course of 1 to 5 years. Most forms of ALS are sporadic, but ~10% of patients have an inherited familial form of the disease and a clear family history. Understanding of ALS pathogenesis began

Clotilde Lagier-Tourenne; Don W. Cleveland

2009-01-01

260

Correlation between Al2O3 particles and interface of Al Al2O3 coatings by cold spray  

NASA Astrophysics Data System (ADS)

Al Al2O3 composite coatings with different Al2O3 particle shapes were prepared on Si and Al substrate by cold spray. The powder compositions of metal (Al) and ceramic (Al2O3) having different sizes and agglomerations were varied into ratios of 10:1 wt% and 1:1 wt%. Al2O3 particles were successfully incorporated into the soft metal matrix of Al. It was found that crater formation between the coatings and substrate, which is typical characteristic signature of cold spray could be affected by initial starting Al2O3 particles. In addition, when the large hard particles of fused Al2O3 were employed, the deep and big craters were generated at the interface between coatings and hard substrates. In the case of pure soft metal coating such as Al on hard substrate, it is very hard to get proper adhesion due to lack of crater formation. Therefore, the composite coating would have certain advantages.

Lee, Ha Yong; Jung, Se Hun; Lee, Soo Yong; You, Young Ho; Ko, Kyung Hyun

2005-12-01

261

Nanoscale interaction layer at the interface between Al films and SiO2 substrates of Al/AlOx/Al Josephson tunnel junctions  

NASA Astrophysics Data System (ADS)

An interaction layer is found at the Al/SiO2 interface in Al/AlOx/Al tunnel junctions grown on SiO2 substrates. The amorphous intermixing layer has an average thickness of about 5 nm. We present the detailed structure of this interfacial layer as determined by transmission electron microscopy. The layer contains alumina with aluminum being octahedrally coordinated according to electron energy loss spectroscopy analysis rather than tetrahedrally coordinated, where the latter coordination is the most common type in amorphous alumina. Depth profiles of the Al-O and Si-O bonding characteristics were also investigated using energy loss near edge structure.

Zeng, L. J.; Greibe, T.; Nik, S.; Wilson, C. M.; Delsing, P.; Olsson, E.

2013-04-01

262

Oxidation induced softening in Al nanowires  

NASA Astrophysics Data System (ADS)

The mechanical properties of metallic nanowires depend dramatically on the atmospheric conditions. Molecular-dynamics simulations with ReaxFF were conducted to study tensile elastic deformation of oxidized Al nanowires. The thin amorphous oxide shell formed around Al nanowires had a very low Young's modulus of 26 GPa, due to its low density and low Al-O coordination. Consequently, for diameters less than 100 nm, the composite Young's modulus of oxide-covered Al nanowires showed a size dependence implying that in this case ``smaller is softer.'' The model developed also explained the discrepancies in the reported modulus values of nanometer-scale Al thin films.

Sen, Fatih G.; Qi, Yue; van Duin, Adri C. T.; Alpas, Ahmet T.

2013-02-01

263

A Thermodynamic Description of the Al-Cr-Si System  

Microsoft Academic Search

The Al-Cr-Si system was critically assessed using the CALPHAD technique. The solution phases (liquid, bcc, fcc, and diamond)\\u000a were described by a substitutional solution model. The compounds CrSi2, Cr3Si, AlCr2, ?Al8Cr5, ?Al8Cr5, Al4Cr, and Al11Cr2 in the Al-Cr-Si system were treated with sublattice models (Cr, Si)(Al, Cr, Si)2, (Cr, Si)3(Al, Cr, Si), (Al, Cr, Si)(Al, Cr)2, ?(Al, Cr, Si)8(Al, Cr,

Yu Liang; Cuiping Guo; Changrong Li; Zhenmin Du

2009-01-01

264

High-temperature tribological properties of CrAlN, CrAlSiN and AlCrSiN coatings  

Microsoft Academic Search

Cr–Al–Si–N coatings with high and low Cr\\/Al ratios (CrAlSiN and AlCrSiN, respectively) were deposited on WC substrates by cathodic arc and compared with a reference Cr–Al–N coating. The silicon content was close to 3at.%. X-ray diffraction analysis showed that CrAlN and CrAlSiN coatings exhibited the cubic Cr(Al)N structure, whereas in AlCrSiN a mixture of cubic Cr(Al)N and wurtzite-type AlN was

Tomas Polcar; Albano Cavaleiro

2011-01-01

265

Instandhaltungsmanagement als Gestaltungsfeld Ganzheitlicher Produktionssysteme  

NASA Astrophysics Data System (ADS)

Sich kontinuierlich verändernde Rahmenbedingungen, wie beispielsweise eine steigende Variantenvielfalt, verkürzte Produktlebenszyklen sowie Kundenforderungen nach höherer Qualität, kürzeren Lieferzeiten und geringeren Kosten, fordern von produzierenden Unternehmen eine stetige Anpassung der Prozesse, der Organisation und der Strukturen. Seit den 90er Jahren versuchen immer mehr deutsche Unternehmen diesen veränderten Anforderungen mit der Einführung eines Ganzheitlichen Produktionssystems (GPS) zu begegnen. Ganzheitliche Produktionssysteme sind dabei in ihren Grundlagen an das Toyota Produktionssystem angelehnt, vereinigen aber auch weitere Methoden zu einem unternehmensspezifischen Regelwerk. Im Rahmen des langfristigen Trends zu unternehmensindividuellen Produktionssystemen wird sowohl in der Industrie als auch in der Forschung intensiv über das Toyota Produktionssystem, Lean Production, Lean Management und Ganzheitliche Produktionssysteme diskutiert, werden Konzepte zu Implementierung und Betrieb erstellt und die Wirtschaftlichkeit untersucht.

Dombrowski, Uwe; Schulze, Sven; Otano, Isabel Crespo

266

Reactive Plasma Spraying of Fine Al2O3/AlN Feedstock Powder  

NASA Astrophysics Data System (ADS)

Reactive plasma spraying (RPS) is a promising technology for in situ formation of aluminum nitride (AlN) coatings. Recently, AlN-based coatings were fabricated by RPS of alumina (Al2O3) powder in N2/H2 thermal plasma. This study investigated the feasibility of RPS of a fine Al2O3/AlN mixture and the influence of the plasma gases (N2, H2) on the nitriding conversion, and coating microstructure and properties. Thick AlN/Al2O3 coatings with high nitride content were successfully fabricated. The coatings consist of h-AlN, c-AlN, Al5O6N, ?-Al2O3, and a small amount of ?-Al2O3. Use of fine particles enhanced the nitriding conversion and the melting tendency by increasing the surface area. Furthermore, the AlN additive improved the AlN content in the coatings. Increasing the N2 gas flow rate improved the nitride content and complete crystal growth to the h-AlN phase, and enhanced the coating thickness. On the other hand, though the H2 gas is required for plasma nitriding of the Al2O3 particles, increasing its flow rate decreased the nitride content and the coating thickness. Remarkable influence of the plasma gases on the coating composition, microstructure, and properties was observed during RPS of the fine particles.

Shahien, Mohammed; Yamada, Motohiro; Yasui, Toshiaki; Fukumoto, Masahiro

2013-10-01

267

Nucleation and Precipitation Strengthening in Dilute Al-Ti and Al-Zr Alloys  

NASA Astrophysics Data System (ADS)

Two conventionally solidified Al-0.2Ti alloys (with 0.18 and 0.22 at. pct Ti) exhibit no hardening after aging up to 3200 hours at 375 °C or 425 °C. This is due to the absence of Al3Ti precipitation, as confirmed by electron microscopy and electrical conductivity measurements. By contrast, an Al-0.2Zr alloy (with 0.19 at. pct Zr) displays strong age hardening at both temperatures due to precipitation of Al3Zr (L12) within Zr-enriched dendritic regions. This discrepancy between the two alloys is explained within the context of the equilibrium phase diagrams: (1) the disparity in solid and liquid solubilities of Ti in ?-Al is much greater than that of Zr in ?-Al; and (2) the relatively small liquid solubility of Ti in ?-Al limits the amount of solute retained in solid solution during solidification, while the comparatively high solid solubility reduces the supersaturation effecting precipitation during post-solidification aging. The lattice parameter mismatch of Al3Ti (L12) with ?-Al is also larger than that of Al3Zr (L12), further hindering nucleation of Al3Ti. Classical nucleation theory indicates that the minimum solute supersaturation required to overcome the elastic strain energy of Al3Ti nuclei cannot be obtained during conventional solidification of Al-Ti alloys (unlike for Al-Zr alloys), thus explaining the absence of Al3Ti precipitation and the presence of Al3Zr precipitation.

Knipling, Keith E.; Dunand, David C.; Seidman, David N.

2007-10-01

268

Conversion of Al 13 Keggin ? into Al 30: a reaction controlled by aluminum monomers  

Microsoft Academic Search

In situ 27Al NMR experiments under hydrothermal and room temperature conditions demonstrate that aluminum monomers are the species controlling the Al13 Keggin ? conversion into Al30. New 27Al NMR signatures of Keggin-type aluminum polycation are observed in solution. A chemical pathway is proposed to explain the isomerization process.

Lionel Allouche; Francis Taulelle

2003-01-01

269

A surface-potential-based model for AlGaN/AlN/GaN HEMT  

NASA Astrophysics Data System (ADS)

A new surface-potential-based model for AlGaN/AlN/GaN high electron mobility transistor (HEMT) is proposed in this paper. Since the high polarization effects caused by AlN interlayer favorably influence the two dimensional electron gas (2DEG) and scattering mechanisms, we first add spontaneous and piezoelectric charge terms to the source equation of surface-potential, and a mobility model for AlGaN/AlN/GaN HEMT is rewritten. Compared with TCAD simulations, the DC characteristics of AlGaN/AlN/GaN HEMT are faithfully reproduced by the new model.

Jie, Wang; Lingling, Sun; Jun, Liu; Mingzhu, Zhou

2013-09-01

270

Adhesion and nonwetting-wetting transition in the Al\\/alpha-Al2O3 interface  

Microsoft Academic Search

Using a reactive force field (ReaxFF), we investigated the structural, energetic, and adhesion properties, of both solid and liquid Al\\/alpha-Al2O3 interfaces. The ReaxFF was developed solely with ab initio calculations on various phases of Al and Al2O3 and Al-O-H clusters. Our computed lattice constants, elastic constants, surface energies, and calculated work of separation for the solid-solid interface agree well with

Qing Zhang; Tahir Çagin; Adri van Duin; William A. Goddard; Yue Qi; Louis G. Hector

2004-01-01

271

Effect of native Al 2O 3 on the elastic response of nanoscale Al films  

Microsoft Academic Search

A continuous, dense aluminum oxide (Al2O3) layer of about 5 nm forms on the surface of Al upon exposure to oxygen or dry air. Since the elastic moduli of Al and Al2O3 are 69 GPa and 370 GPa, respectively, the elastic modulus of a thin Al film of sub-micron dimension (with the native oxide layer) should be much higher than

M. T. A. Saif; S. Zhang; A. Haque; K. J. Hsia

2002-01-01

272

Effect of thermomechanical treatment on the properties of Fe11Al and Fe14Al alloys  

Microsoft Academic Search

Fe-Al alloys have the potential to be relatively inexpensive soft magnetic materials if their formability could be improved. An investigation has been made on the effect of thermomechanical treatment on the properties of Fe-11 wt%Al and Fe-14 wt%Al alloys (designated Fe-11Al and Fe-14Al respectively). For the former the room temperature mechanical properties were found to be determined principally by the

Syahril; R. D. Rawlings

2002-01-01

273

Atom probe analysis of AlN interlayers in AlGaN/AlN/GaN heterostructures  

NASA Astrophysics Data System (ADS)

Atom probe tomography was used to characterize AlN interlayers in AlGaN/AlN/GaN heterostructures grown by plasma-assisted molecular beam epitaxy (PAMBE), NH3-based molecular beam epitaxy (NH3-MBE), and metal-organic chemical vapor deposition (MOCVD). The PAMBE-grown AlN interlayer had the highest purity, with nearly 100% of group-III sites occupied by Al. The group-III site concentrations of Al for interlayers grown by NH3-MBE and MOCVD were ~85% and ~47%, respectively. Hall measurements were performed to determine the two-dimensional electron gas mobility and sheet concentration. Sheet concentrations were ~25%-45% higher with molecular beam epitaxy than with MOCVD, and these results matched well with atom probe data.

Mazumder, Baishakhi; Kaun, Stephen W.; Lu, Jing; Keller, Stacia; Mishra, Umesh K.; Speck, James S.

2013-03-01

274

Development of Al2O3 fiber-reinforced Al2O3-based ceramics.  

PubMed

The purpose of this study was to use a tape casting technique to develop an Al2O3 fiber-reinforced Al2O3-based ceramic material (Al2O3-fiber/Al2O3 composite) into a new type of dental ceramic. The Al2O3-based ceramic used a matrix consisting of 60 wt% Al2O3 powder and 40 wt% SiO2-B2O3 powder. The prepreg sheets of Al2O3-fiber/Al2O3 composite (in which uniaxially aligned Al2O3 fibers were infiltrated with the Al2O3-based matrix) were fabricated continuously using tape casting technique with a doctor blade system. Multilayer preforms of Al2O3-fiber/Al2O3 composite sheets were then sintered at a maximum temperature of 1000 degrees C under an atmospheric pressure in a furnace. The results showed that the shrinkage and bending properties of Al2O3-fiber/Al2O3 composite exceeded those of unreinforced Al2O3--hence demonstrating the positive effects of fiber reinforcement. In conclusion, the tape casting technique has been utilized to successfully develop a new type of dental ceramic material. PMID:15510857

Tanimoto, Yasuhiro; Nemoto, Kimiya

2004-09-01

275

Contribution of interface capacitance to the electric-field breakdown in thin-film Al-AlOx-Al capacitors  

NASA Astrophysics Data System (ADS)

We present a systematic study of the dependence of breakdown voltages on oxide thickness d in Al-AlOx-Al thin-film capacitor structures. For sufficiently thin dielectrics, we find that a significant portion of the measured breakdown potential Vb occurs across the electrode interfaces, thereby leading to an overestimate (Vb/d) of the true breakdown electric field Eb across the dielectric. By modeling this interface contribution as an ``interface'' capacitance in series with the geometric ``bulk'' capacitance, we find for high-quality rf magnetron-sputtered AlOx dielectrics that Eb is independent of d over the range 30-300 Å.

Singh-Bhalla, Guneeta; Du, Xu; Hebard, Arthur F.

2003-09-01

276

Reply to Vance et al.  

SciTech Connect

In our report of a family with a motor and sensory polyneuropathy that was linked to chromosome 3q, we classified this neuropathy as a form of hereditary motor and sensory neuropathy II (HMSN II, also known as {open_quotes}CMT2{close_quotes}). Doubts have been raised by Vance et al. as to whether this neuropathy should be classified as hereditary sensory autonomic neuropathy I (HSAN I) instead of HMSN II. While it is reasonable to raise such doubts, we believe that the neuropathy is best designated as HMSN II for the reasons described below. The group of disorders described as HSAN are characterized by primary or predominant involvement of sensory and autonomic neurons that fail to develop or that undergo atrophy and degeneration. These disorders were extensively reviewed by Dyck and Ohta, who initially described them as the hereditary sensory neuropathies (HSN). It was Dyck who subsequently suggested that these disorders be designated HSAN rather than HSN, because of the presence of autonomic involvement. 8 refs.

Woon-Chee Yee; Elliott, J.L; Kwon, J.M.; Goodfellow, P. [Washington Univ. School of Medicine, St. Louis, MO (United States)

1996-07-01

277

Una aproximación didáctica al Guernica de Picasso  

Microsoft Academic Search

L’article presenta una aproximació al Guernica, de Pablo Picasso, mitjançant l’anàlisi de les seves possibilitats per a l’estudi de la pintura i de la relació entre la creació i el coneixement de la Història de l’Art. Al mateix temps, es presenta un model de treball que s’inicia amb una mirada als problemes derivats de l’observació per tal d’assolir la interpretació

Antonia Fernández Valencia

2003-01-01

278

Structure of amorphous Al2O3  

NASA Astrophysics Data System (ADS)

The structure of amorphous Al2O3 samples, prepared by anodic oxidation of aluminium foils, was investigated by X-ray and neutron diffraction. The partial pair correlation functions were determined from computer simulation of the structure using the Reverse Monte Carlo method with the result that amorphous Al2O3 is built up by AlO4 tetrahedra with corner sharing oxygen atoms. Pores in the material were characterized by neutron small-angle scattering.

Lamparter, P.; Kniep, R.

1997-02-01

279

DZ Bank als Integrator im Netzwerk  

Microsoft Academic Search

Die DZ Bank mit Hauptsitz Frankfurt am Main wurde 1883 als Landwirtschaftliche Genossenschaftsbank der hessischen Darlehnskassenvereine\\u000a gegründet. Aus zahlreichen Fusionen und Übernahmen ist die viertgrösste deutsche Bank, die heutige DZ Bank AG, entstanden.\\u000a Innerhalb des deutschen genossenschaftlichen Bankensektors, auch Finanzverbund genannt, fungiert die DZ Bank AG (s. Bild 11-1)\\u000a als eines von zwei Zentralinstituten für mehr als 1.000 Genossenschaftsbanken mit

Jens Wolf; Falk Kohlmann

280

Interpretation of 26Al in Meteoritic Inclusions  

Microsoft Academic Search

We suggest that the large 26Al\\/27Al = 5 x 10-5 abundance ratio found in calcium-aluminum--rich inclusions (CAIs) in meteorites is produced by energetic particle irradiation in the early solar system but only in a thin (0.2 g cm-2) skin of the solar preplanetary disk that stops the energetic particles. Buildup of that 26Al concentration happens only during the quiescent, or

Donald D. Clayton; Liping Jin

1995-01-01

281

AL-QAEDA AND WESTERN ISLAM  

Microsoft Academic Search

The terrorism of Al-Qaeda could gravely endanger social co-existence in western countries with large Islamic communities. Al-Qaeda uses the presence of Muslims in Europe and the United States in order to hide itself, recruit new members and obtain aid. Even though the majority of the Muslims who live in the West reject terrorism, there exists proof that Al-Qaeda has managed

Javier Jordan; Luisa Boix

2004-01-01

282

al-Qaeda: An Agile Enterprise  

Microsoft Academic Search

This paper describes the preliminary results of efforts to use soft systems thinking and analy- sis to better understand the agility of the al-Qaeda network. The application of systems tools to a social phenomenon has led to insights on what makes the al-Qaeda extended enterprise agile. Examining the response ability of elements which allow al-Qaeda to recover and restore opera-

Nicole Long; Trina Powell Richard Fekecs; Paul Petersen; Vicente Tur-Rojas; Art Pyster

2008-01-01

283

Photoionization spectroscopy of LiAl  

NASA Astrophysics Data System (ADS)

An electronic spectrum is observed for the new heteronuclear metal dimer, LiAl. This dimer is produced by laser vaporization of an alloy metal sample in a pulsed nozzle cluster source. Resonant two-photon photoionization (R2PI) is employed to collect this spectrum. We observe and characterize two excited electronic states for both the (6)Li-Al and (7)Li-Al isotopes. The analysis of hotbands provides the vibrational frequency (318.3/cm) and dissociation energy (0.75 eV) for the LiAl ground state, which both agree well with the predictions of ab initio theory.

Brock, L. R.; Pilgrim, J. S.; Duncan, M. A.

1994-11-01

284

Thalidomide causes sinus bradycardia in ALS  

Microsoft Academic Search

Objective\\u000a   Neuroinflammation contributes to motor neuron degeneration in ALS. Thalidomide (THL) shows potent anti-inflammatory properties\\u000a and increased the lifespan in ALS transgenic mice. Thalidomide was therefore suggested as atherapeutic intervention for the\\u000a treatment of ALS.We conducted a pilot, randomized clinical trial of THL in patients with ALS to assess safety, feasibility,\\u000a and preliminary estimates of treatment efficacy.\\u000a \\u000a \\u000a \\u000a \\u000a Methods\\u000a   Patients were

Thomas Meyer; André Maier; Nadja Borisow; Jörn S. Dullinger; G. Splettstößer; S. Ohlraun; C. Münch; P. Linke

2008-01-01

285

Crack growth resistance ( R-curve) behaviour and thermo-physical properties of Al 2O 3 particle-reinforced AlN\\/Al matrix composites  

Microsoft Academic Search

Crack growth resistance behaviour and thermo-physical properties of Al2O3 particle-reinforced AlN\\/Al matrix composites have been studied as a function of AlN volume fraction as well as Al2O3 particle size. The fracture toughness of the composites decreased with increase in vol% AlN and decrease in Al2O3 particle size. All the composites exhibited R-curve behaviour which has been attributed to crack bridging

Srinivasa Rao Boddapati; Jürgen Rödel; Vikram Jayaram

2007-01-01

286

High temperature properties of CrAlN, CrAlSiN and AlCrSiN coatings – Structure and oxidation  

Microsoft Academic Search

CrAlN, CrAlSiN and AlCrSiN coatings were deposited by cathodic arc deposition technique from composite targets. Three targets were used: (i) Cr\\/Al ratio close to 1, (ii) Cr\\/Al ratio close to 1 with Si addition, and (iii) Cr\\/Al ratio close to 1\\/2 and Si addition. Nitrogen flow was kept constant during the depositions. The Cr\\/Al ratio of the films, measured by

Tomas Polcar; Albano Cavaleiro

2011-01-01

287

Al2Ti precipitation in Al64Fe8Ti28 alloy  

NASA Astrophysics Data System (ADS)

Precipitates of Al2Ti with three different stacking sequences have been observed in Fe-modified Ll2-type ordered Al3Ti specimens. Two of the stacking sequences have been observed previously. The third type of Al2Ti, Al2TiIII, is identified in this study using conventional and highresolution transmission electron microscopy (TEM). The Al2Ti precipitates form as plates along {100} planes and compression tests performed at liquid N temperature show microcracks occurring along those {100} planes. The Al2Ti phase is believed to be responsible for the low cleavage strength that is observed.

Yang, T. Y.; Goo, E.

1994-04-01

288

Effects of the Al content on pore structures of porous TieAl alloys  

SciTech Connect

PorousTi Alalloys with different nominal compositions were fabricated through a reactive synthesis of Ti and Al elemental powders. It has been found that the pore parameters vary with the Al contents, indicating that the nature of the pores can be manipulated through changing the Al contents. In addition, detailed structural characterizations showed that the fabricated porousTi Alalloys can have three crystalline phases (i.e., 2-Ti3Al, -TiAl, and TiAl3) when using different compositions. The fundamental reasons behind these phenomena have been explored.

Jiang, Y [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; He, Y H [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; Zou, J [School of Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, QLD; Huang, B [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China; Liu, C [Oak Ridge National Laboratory (ORNL)

2008-01-01

289

Deletion of ALS5, ALS6 or ALS7 increases adhesion of Candida albicans to human vascular endothelial and buccal epithelial cells  

PubMed Central

Summary C. albicans yeast forms deleted for ALS5, ALS6 or ALS7 are more adherent than a relevant control strain to human vascular endothelial cell monolayers and buccal epithelial cells. In the buccal and vaginal reconstituted human epithelium (RHE) disease models, however, mutant and control strains caused a similar degree of tissue destruction. Deletion of ALS5 or ALS6 significantly slowed growth of the mutant strain; this phenotype was not affected by addition of excess uridine to the culture medium. These studies demonstrate similar phenotypic characteristics for the als5?/als5?, als6?/als6? and als7?/als7? strains that are not observed in any of the other C. albicans als?/als? strains.

ZHAO, XIAOMIN; OH, SOON-HWAN; HOYER, LOIS L.

2009-01-01

290

Stress Corrosion Cracking of Al-Mg and Mg-Al Alloys  

SciTech Connect

Aluminum and magnesium based alloys are being used for reducing the weight of automobiles. For structural applications they must have adequate stress corrosion resistance and yet, under some circumstances, stress corrosion cracking can occur in both alloy systems. Precipitation of the Mg rich Beta-phase (Al3Mg2) at grain boundaries of Al-Mg alloys and the Beta-phase (Mg17Al12) at grain boundaries of the Mg-Al alloys are critical factors in their stress corrosion performance. In Mg-Al, the Beta-phase is cathodic to the matrix while in the Al-Mg case, the Beta-phase is anodic to the matrix. These phases produce localized galvanic induced-corrosion that leads to intergranular stress corrosion cracking and cracking growth rates of 5 and 103 times faster than the solution treated condition, for Al-Mg and Mg-Al, respectively.

Jones, Russell H.; Vetrano, John S.; Windisch, Charles F.

2004-12-01

291

The Contours of Al Qaeda's Media Strategy  

Microsoft Academic Search

Al Qaeda has crafted a successful media strategy that is adeptly suited for the war of ideas against the United States. Osama bin Laden and Ayman al-Zawahiri have demonstrated a great ability to lead plural groups and exploit innovation with the use of technology. This article explores how they have connected with diverse audiences around the world with a constant

Carl J. Ciovacco

2009-01-01

292

Half Life of exp 26 Al.  

National Technical Information Service (NTIS)

The half-life of exp 26 Al has been redetermined because of suggestions of an error in the accepted value based on its use in calculating exp 21 Ne production rates from cosmic rays in meteorites. Two solutions of exp 26 Al were analyzed for the specific ...

T. L. Norris A. J. Gancarz D. J. Rokop K. W. Thomas

1983-01-01

293

Al Shabaab's Foreign Threat to Somalia  

Microsoft Academic Search

This article focuses on the threat to Somalia by al Shabaab (The Youth), an extremist organization that controls most of southern and central Somalia. It learned its strategy and tactics from al Qaeda and the Taliban and relies heavily on a relatively small number of foreign fighters, most of whom are Somalis with foreign passports from the large Somali diaspora.

David Shinn

2011-01-01

294

Diana Al-Hadid: Identity and Heritage  

ERIC Educational Resources Information Center

|Diana Al-Hadid's sculptures reflect the many locations, cultures, histories, and mythologies that have shaped her as an artist. In large-scale works which have the appearance of architectural ruins, Al-Hadid employs imagery drawn from many diverse interests including science and technology, history, and literature. She also incorporates images…

Jungerberg, Tom; Smith, Anna; Borsh, Colleen

2012-01-01

295

Future of Al Qa'ida.  

National Technical Information Service (NTIS)

The death of Osama bin Laden has triggered a re-evaluation of al Qa'ida and its threat to the United States. Some have argued that al Qa'ida will become increasingly irrelevant. 'Between the Arab Spring and the death of bin Laden, it is hard to imagine gr...

S. G. Jones

2011-01-01

296

Al Qaeda: Profile and Threat Assessment.  

National Technical Information Service (NTIS)

There is no consensus among experts in and outside the U.S. Government about the magnitude of the threat to U.S. national interests posed by the Al Qaeda organization. Experts agree that Al Qaeda and its sympathizers intend to conduct major attacks in the...

K. Katzman

2005-01-01

297

Secondary recrystallisation in magnox AL 80  

Microsoft Academic Search

Exaggerated grain growth observed in the magnesium canning alloy Magnox ; AL 80 (Al\\/0.8 wt%, Be\\/0.004 wt%) is typical of the phenomenon classified as ; Secondary Recrystallization. Studies on alloys of varying composition indicate ; that the presence of 40 ppm beryllium is of particular importance in promoting ; the effect. Metallographic observations indicate that both marked equilibrium ; segregation

G. Higgins

1963-01-01

298

Crack growth resistance and strength of the B2 iron aluminides Fe-40Al, Fe-45Al, and Fe-10Ni-40Al (at. %).  

National Technical Information Service (NTIS)

The crack growth resistance and yield strength of the B2 iron aluminides Fe-40Al, Fe-45Al, are Fe-10Ni-40Al (at. %) have been investigated at room temperature laboratory air. After fast cooling from 1273 K, Fe-45Al and Fe-10Ni-40Al are much stronger than ...

J. H. Schneibel P. J. Maziasz

1994-01-01

299

Al-Akhawayni's description of pulmonary circulation.  

PubMed

Since antiquity, heart function and the mechanism of blood circulation within the human body have been the focus of attention of scientists from different parts of the world. Over the passage of time, the theories and works of these scientists have resulted in the achievement of today's knowledge of circulation. The medieval Persian scholar, Al-Akhawayni Bukhari (?-983AD), is among the physicians who investigated both the anatomy and the physiology of the human body. Al-Akhawayni describes the mechanism of pulmonary circulation in his only extant book, "Hidayat al-Muta`llemin fi al-Tibb" (A Scholar's Guide to Medicine) with which he made a contribution to the development of knowledge regarding this mechanism in the medicine of the Islamic world. In this paper, Al-Akhawayni's viewpoints on anatomy and the function of the heart, its related vessels, and also pulmonary circulation will be briefly discussed. PMID:23890868

Yarmohammadi, Hassan; Dalfardi, Behnam; Rezaian, Jafar; Ghanizadeh, Ahmad

2013-07-25

300

High temperature creep behaviour of Al-rich Ti-Al alloys  

NASA Astrophysics Data System (ADS)

Compared to Ti-rich ?-TiAl-based alloys Al-rich Ti-Al alloys offer an additional reduction of in density and a better oxidation resistance which are both due to the increased Al content. Polycrystalline material was manufactured by centrifugal casting. Microstructural characterization was carried out employing light-optical, scanning and transmission electron microscopy and XRD analyses. The high temperature creep of two binary alloys, namely Al60Ti40 and Al62Ti38 was comparatively assessed with compression tests at constant true stress in a temperature range between 1173 and 1323 K in air. The alloys were tested in the cast condition (containing various amounts of the metastable phases Al5Ti3 and h-Al2Ti) and after annealing at 1223 K for 200 h which produced (thermodynamically stable) lamellar ?-TiAl + r-Al2Ti microstructures. In general, already the as-cast alloys exhibit a reasonable creep resistance at 1173 K. Compared with Al60Ti40, both, the as-cast and the annealed Al62Ti38 alloy exhibit better creep resistance up to 1323 K which can be rationalized by the reduced lamella spacing. The assessment of creep tests conducted at identical stress levels and varying temperatures yielded apparent activation energies for creep of Q = 430 kJ/mol for the annealed Al60Ti40 alloy and of Q = 383 kJ/mol for the annealed Al62Ti38 material. The latter coincides well with that of Al diffusion in ?-TiAl, whereas the former can be rationalized by the instability of the microstructure containing metastable phases.

Sturm, D.; Heilmaier, M.; Saage, H.; Aguilar, J.; Schmitz, G. J.; Drevermann, A.; Palm, M.; Stein, F.; Engberding, N.; Kelm, K.; Irsen, S.

2010-07-01

301

The tensile properties of hot-rolled (Al 2O 3) pAl composites  

Microsoft Academic Search

Hot rolling was carried out on the extruded Al alloy 6061 composite reinforced with Al2O3 particulates ((Al2O3)p-Al composite) along a direction perpendicular to the extrusion direction of the composite. Room-temperature tensile tests of the hot-rolled composites showed a significant increase in strength and fracture strain along the transverse (rolling) direction with increasing reduction in rolling. However, the same properties along

J. C. Lee; K. N. Subramanian

1995-01-01

302

Young's modulus of cold- and hot-rolled (Al 2 O 3 ) p Al composite  

Microsoft Academic Search

The Young's modulus of hot-rolled Al alloy reinforced with Al2O3 particulates, (Al2O3)p-Al composite, is measured using the dynamic sonic resonance test method. The variation in the moduli of cold- and hot-rolled composites, as a function of the reduction ratio, is compared. Although both cold and hot rolling result in more uniform distribution of the particulates, hot rolling causes less damage

J. C. Lee; K. N. Subramanian

1994-01-01

303

Assessment of isotopically exchangeable Al in soil materials using 26Al tracer  

NASA Astrophysics Data System (ADS)

The solubility of aluminium (Al) in many acidic soils is controlled by complexation reactions with soil organic matter. In such soils, Al solubility is theoretically a function of the pool size of "active" Al, i.e., the total amount of Al that equilibrates with the soil solution within a defined period of time. To date, no reliable measurements of "active" Al in soil materials exist. In this study, we determined the isotopically exchangeable pool of Al ( EAl) as an operationally defined assessment of "active" Al in acidic mineral soils. The suitability of CuCl 2 and pyrophosphate (Na 4P 2O 7) as extractants for "active" Al was also evaluated. Eleven samples, mostly from spodic B horizons, were spiked with carrier-free 26Al and equilibrated for different time periods (1-756 h). The size of the Al pool with which the 26Al tracer exchanged increased with time during the whole experimental period. Thus, contact time between solid and solution phases needs to be defined when assessing the "active" Al pool. Values of EAl obtained after 1 to 5 d of equilibration were equal to the amount of CuCl 2 extractable Al, but considerably smaller than the Na 4P 2O 7-extractable pool. Equilibration times greater than 5 d resulted in CuCl 2 extractable Al concentrations that under-estimated the "active" Al pool. Three of the investigated samples were rich in imogolite-type materials (ITM). In these samples, 30-50 % of the added 26Al rapidly became associated with soil constituents in forms that could not be extracted by Na 4P 2O 7, indicating that a part of ITM may be in a dynamic state.

Kleja, D. Berggren; Standring, W.; Oughton, D. H.; Gustafsson, J.-P.; Fifield, K.; Fraser, A. R.

2005-11-01

304

Widely tunable Fabry-Perot filter using Ga(Al)As-AlOx deformable mirrors  

Microsoft Academic Search

A microelectromechanically tunable Fabry-Perot (FP) microinterferometer is demonstrated using Ga(Al)As-AlOx DBR micromirrors separated by an air gap. The broad-spectral response of Ga(Al)As-AlOx distributed Bragg reflector (DBR) micromirrors allows 3-dB bandwidth of the cavity to remain narrow and stable over the tuning range. Two devices with different number of mirror structures were demonstrated exhibiting linewidths of 0.5 and 2.0 nm, tuning

P. Tayebati; P. D. Wang; D. Vakhshoori; Robert N. Sacks

1998-01-01

305

Formation and properties of Al composites reinforced by quasicrystalline AlCuFeB particles  

Microsoft Academic Search

Al-based composites reinforced by icosahedral (i-) Al59Cu25.5Fe12.5B3 quasicrystalline particles were prepared by solid-state sintering. It was found that Al diffusion from the matrix to the quasicrystalline particles induces phase transformation into the ?-Al7Cu2Fe tetragonal phase. In order to preserve the i phase, we used an oxidation pre-treatment of the particles and studied its influence on the kinetics of the phase

S. Kenzari; P. Weisbecker; M. Curulla; G. Geandier; V. Fournee; J. M. Dubois

2008-01-01

306

Selenium adsorption on Mg–Al and Zn–Al layered double hydroxides  

Microsoft Academic Search

Layered double hydroxides (LDHs) have high anion exchange capacities that enhances their potential to remove anionic contaminants from aqueous systems. In this study, different Mg–Al and Zn–Al LDHs were synthesized by a coprecipitation method, with the products evaluated for their ability to adsorb selenite (SeO32?) and selenate (SeO42?). Results indicated the adsorption isotherm for SeO32? retention by Mg–Al and Zn–Al

Youwen You; George F Vance; Hongting Zhao

2001-01-01

307

Wet oxidation of AlGaAs vs. AlAs: A little gallium is good  

Microsoft Academic Search

In summary, buried oxides formed from the wet oxidation of AlGaAs alloys, rather than AlAs, are found to be superior in terms of oxidation isotropy, mechanical stability, and strain. It is not surprising that VCSELs using AlGaAs oxide layers as current apertures have shown promising reliability as compared to VCSELs using AlAs layers. Comparisons of lifetime data for VCSELs with

Kent D. Choquette; K. M. Geib; Robert Hull; H. Q. Hou; K. L. Lear; H. C. Chuia; B. E. Hammons; J. A. Nevers

1996-01-01

308

Al-MCM-41 sorbents for bovine serum albumin: relation between Al content and performance  

Microsoft Academic Search

The adsorption of bovine serum albumin (BSA) onto Al-MCM-41 samples with different Si\\/Al ratio and pore width about 36Å was studied. It is shown that the adsorption capacity of Al-MCM-41 increased with decreasing of the Si\\/Al ratio, probably due to the increased affinity of BSA for the external surface of the adsorbents. The materials synthesized are agglomerates of primary particles,

Lei Ji; Amit Katiyar; Neville G. Pinto; Mietek Jaroniec; Panagiotis G. Smirniotis

2004-01-01

309

Properties of Sintered Al Substituted NdFeB Magnets  

NASA Astrophysics Data System (ADS)

The effect of partial substitution of Fe by Al (Al, Al2O3) on the magnetic properties and the corrosion resistance of the sintered NdFeB magnet has been investigated. With the increasing amount of Al, the anisotropy field and the saturation magnetization decrease, but the coercivity increases up to 4 at.% Al and further alloying of Al leads to a decrease of the coercivity. Different substances like Al (metallic Al or Al2O3) modify the microstructure to different increase in the coercivity and especially to changes in the remanence. Alloying Al via metallic Al decreases the remanence, whereas via Al2O3) up to 4 at.%0 Al increases it. The Al additions inhibit atmospheric corrosion of the magnet. We have found that Al2O3 in sintered NdFeB magnet substantially improves the coercivity and the corrosion resistance with the improved remanence.

Szymura, S.; Bala, H.; Rabinovich, Yu. M.; Wiechu?a, J.

310

EFFECT OF AL PARTICLE SIZE ON THE THERMAL DEGRADATION OF AL\\/TEFLON MIXTURES  

Microsoft Academic Search

Reactive mixtures of aluminum (Al) and polytetrafluoroethylene (PTFE or Teflon) have applications in propellants, explosives, and pyrotechnics. This study examines the thermal degradation behavior of Teflon and nanometer scale Al particles compared with micron-scale Al particles. Differential scanning calorimetry and thermo-gravimetric analyses were performed in an argon environment on both nanometer and micron scale particulate mixtures revealing lower ignition temperatures

DUSTIN T. OSBORNE; MICHELLE L. PANTOYA

2007-01-01

311

Cyclic Oxidation of FeCrAlY/Al2O3 Composites.  

National Technical Information Service (NTIS)

Three-ply FeCrAlY/Al2O3 composites and FeCrAlY matrix-only samples were cyclically oxidized at 1000 C and 1100 C for up to 1000 1-hr cycles. Fiber ends were exposed at the ends of the composite samples. Following cyclic oxidation, cracks running parallel ...

J. A. Nesbitt S. L. Draper C. A. Barrett

1999-01-01

312

Precipitation kinetics in Al6061 and in an Al6061-alumina particle composite  

Microsoft Academic Search

Differential scanning calorimetry (DSC) was used to study the precipitation kinetics of metastable phases in an Al6061 alloy and a 20 vol % alumina particle reinforced Al6061 composite. The thermal effects in the DSC traces were analysed quantitatively. The kinetic parameters for the phase transformations in the Al6061 alloy and composite were calculated using the varying heating rate method and

S. P. Chen; K. M. Mussert; S. van der Zwaag

1998-01-01

313

Water Quality and Planktonic Communities in Al-Khadoud Spring, Al-Hassa,Saudi Arabia  

Microsoft Academic Search

Problem statement: Al-Khadoud spring is one of the most important wat er resources in Al- Hassa Governorate, Saudi Arabia. However, much of its biotic information is still unknown. This study presented preliminary ecological information of thi s aquatic body. The aim of this research was to study the water characteristics and the planktonic organisms inhibiting Al-Khadoud spring and its irrigational

Adel A. Fathi; Mohammed A. Al-Kahtani

2009-01-01

314

Fabrication, phase transformation studies and characterization of SiC-AlN-Al2OC ceramics. Progress report.  

National Technical Information Service (NTIS)

The research effort conducted to date had two specific objectives: (1) to determine phase relations and phase transformations in SiC-AlN, AlN-Al(sub 2)OC, and SiC-Al(sub 2)OC pseudobinary systems and in SiC-AlN-Al(sub 2)OC pseudoternary system, and (2) to...

A. V. Virkar

1990-01-01

315

Al?Al 3Ni eutectic alloy and AL/WC(NI) composite directionally solidified under microgravity and normal gravity  

NASA Astrophysics Data System (ADS)

Directional solidification of Al?Al 3Ni eutectic alloy and Al/WC(Ni) composite were performed in the Multi-functional Crystal Growing Furnace on board the unmanned Chinese Shenzhou II spacecraft and on the ground respectively. The microstructures of the samples were investigated applying metallographic, SEM, XRD and image analysis techniques. Many differences were found between the space samples and the ground samples. It could be concluded that gravity condition had a strong influence on the solidification behavior of materials. The temperature gradient driven convection, i.e. Marangoni Convection, played an apparent role on the formation of solidification microstructure under microgravity.

Luo, X.-H.; Huang, Q.; Liu, B.-D.; Zhang, X.-M.; Li, Y.-Y.

2003-07-01

316

Phase Constituents of Al-rich U-Mo-Al Alloys Examined by Transmission Electron Microscopy  

SciTech Connect

To supplement the understanding of diffusional interactions involving Al-rich region of the U-Mo-Al system, alloys with composition 85.7Al-11.44U-2.86Mo and 87.5Al-10U-2.5Mo in at.%, were examined to determine the equilibrium phase constituents at 500?C. These alloys were triple arc-melted, homogenized at 500?C for 200 hours, and water-quenched to preserve the high temperature microstructure. X-ray diffraction, scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (XEDS), and transmission electron microscopy (TEM) with high angle annular dark field (HAADF) imaging via scanning transmission electron microscopy (STEM) were employed for the characterization. Alloy specimens for TEM/STEM were prepared using site-specific focused ion beam (FIB) in-situ lift-out (INLO) technique. Despite the homogenization time and temperature, five different phases, namely fcc-Al solid solution, cubic-UAl3, orthorhombic-UAl4, hexagonal-U6Mo4Al43 and diamond cubic-UMo2Al20, were observed. Based on U-Al, U-Mo and Al-Mo binary phase diagrams, previously proposed U-Mo-Al isotherms, and the solidification microstructure of these alloys, the Al-rich region of the equilibrium ternary isotherm at 500?C was constructed. The fcc-Al solid solution, orthorhombic-UAl4, and diamond cubic-UMo2Al20, which were determined to be the equilibrium phases in 85.7Al-11.44U-2.86Mo and 87.5Al-10U-2.5Mo alloys.

E. Perez; A. Ewh; J. Liu; B. Yuan; D. D. Keiser, Jr.; Y. H. Sohn

2009-11-01

317

A new discontinuously reinforced aluminum MMC: Al+AlB{sub 2} flakes  

SciTech Connect

Development of a novel metal matrix composite based on the Al-B alloy system has been undertaken. Preparation of this discontinuously reinforced material is based on the precipitation of high aspect ratio AlB{sub 2} from an Al-B alloy. This paper describes a number of efforts forced on preparing high volume fractions (> 30 v%) of AlB{sub 2} in aluminum. New insights into the behavior of the Al-B alloys system allowed this effort to be successful.

HALL,AARON C.; ECONOMY,J.

2000-06-08

318

Thermal conductivity of ?-Al2O3 and ?-Al2O3 wear-resistant coatings  

NASA Astrophysics Data System (ADS)

The thermal conductivities of ?-Al2O3 and ?-Al2O3 wear-resistant coatings are measured using the 3? method in the temperature range 80Al2O3 coating has a thermal conductivity comparable to sapphire at T>300 K. The relatively small thermal conductivity of ?-Al2O3, a factor of ~3 smaller than ?-Al2O3, suggests that this metastable phase of alumina can be applied as an effective thermal barrier for cutting tools.

Cahill, David G.; Lee, S.-M.; Selinder, Torbjörn I.

1998-06-01

319

Extended Al(Mn) solution in a rapidly solidified Al-Li-Mn-Zr alloy  

SciTech Connect

This paper reports the effect of coolingrate on the extension of Mn solid solubility in Al and on the relative amount of MnAl (MnAl{sub 6} and MnAl{sub 4}) secondary phases during gas atomization and spray deposition critically examined. An alloy of composition Al-6.5Mn-2.3Li-0.65Zr (wt pct) currently being investigated for applications requiring high strength and low density at high temperatures was selected for this study. The material was exposed to various solidification histories by altering gas pressure and powder size during solidification.

Ruhr, M.; Baram, J.C. (Materials Engineering Dept., Ben-Gurion Univ. of the Negev, Beer-Sheeva (IL)); Lavernia, E.J. (Materials Section, Mechanical Engineering Dept., Univ. of California, Irvine, CA (US))

1990-06-01

320

Phase stability and microstructure of Al-Ti-Fe near Al3Ti  

NASA Astrophysics Data System (ADS)

The phase stability and microstructure of Al-Ti-Fe near Al3Ti at 800 °C are studied by using high resolution electron microscopy and backscattered electron imaging. One of the most significant changes resulting from the addition of small amounts of iron in this system is to convert tetragonal Al3Ti or Al2Ti into cubic Ll2 structures. In addition, the added iron can change the stacking structure of Al2Ti and the domain size of the long-period one-dimensional antiphase domain structures. A partial ternary phase diagram in this region is also determined.

Yang, T. Y.; Goo, Edward

1995-05-01

321

Phase composition and recrystallization of Al-based Al-Sc-Mn-Zr alloys  

NASA Astrophysics Data System (ADS)

The phase composition and recrystallization of Al-based alloys with small amounts (up to 4 wt %) of transition metals, such as Sc, Mn, and Zr, are studied by metallography and electrical resistivity and hardness measurements. No new phases, besides phases in equilibrium with an Al-based solid solution in the associated ternary systems, are found for the portion of the quaternary Al-Sc-Mn-Zr system under study. It is also found that the manganese and zirconium solubilities in the Al-based solid solution decrease in the presence of scandium and that zirconium additions in Al-Sc-Mn alloys increase their recrystallization temperature.

Rokhlin, L. L.; Bochvar, N. R.; Tarytina, I. E.; Leonova, N. P.

2010-03-01

322

Localized AL amyloidosis: A suicidal neoplasm?  

PubMed Central

Although AL amyloidosis usually is a systemic disease, strictly localized AL deposits are not exceptionally rare. Such case reports form a considerable body of published articles. Although both AL amyloidosis types are formed from an N-terminal segment of a monoclonal immunoglobulin light chain, a typical localized AL amyloid differs from the systemic counterpart by the morphological appearance of the amyloid, and presence of clonal plasma cells and of giant cells. In this article it is pointed out that localized AL amyloidosis (‘amyloidoma') represents a true plasma cell neoplasm and not a pseudotumor. The pathogenesis of localized AL amyloidosis may differ from that of the systemic type, a suggestion underlined by the fact that localized AL amyloidosis of kappa type is as common as that of lambda origin, in contrast to the systemic form where lambda chains constitute the overwhelming majority of cases. It is suggested that oligomeric assemblies of the produced immunoglobulin light chain are toxic to plasma cells, which in this way commit suicide.

2012-01-01

323

Hot-electron drift velocity in AlGaN/AlN/AlGaN/GaN camelback channel  

NASA Astrophysics Data System (ADS)

Nanosecond pulses were employed to study hot-electron transport in a nominally undoped Al0.33Ga0.67N/AlN/{Al0.1Ga0.9N/GaN} heterostructure where the mobile electrons are spread in a composite {Al0.1Ga0.9/GaN} dual channel exhibiting a camelback electron density profile at high electric fields. The highest velocity of ˜1.6× 107 cm s-1 was obtained at electric field of 160 kV cm-1 in the channel with the electron density of 0.8 × 1013?cm-2 owing to its proximity to the LO-phonon-plasmon resonance.

Ardaravi?ius, L.; Kiprijanovi?, O.; Liberis, J.; Matulionis, A.; Li, X.; Zhang, F.; Wu, M.; Avrutin, V.; Özgür, Ü.; Morkoç, H.

2012-12-01

324

Characterization of different-Al-content AlGaN/GaN heterostructures on sapphire  

NASA Astrophysics Data System (ADS)

Al x Ga1- x N/GaN high-electron-mobility transistor (HEMT) structures with Al composition ranging from x = 0.13 to 0.36 are grown on sapphire substrates by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). The effects of Al content on crystal quality, surface morphology, optical and electrical characteristics of the AlGaN/GaN heterostructures have been analyzed. Although high Al-content (36%) heterostructure exhibits a distinguished photoluminescence peak related to recombination between the two-dimensional electron gas and photoexcited holes (2DEG-h), its crystal quality and rough surface morphology are poor. 2DEG mobility increases with the Al content up to 26% and then it apparently decreases for high Al-content (36%) AlGaN/GaN heterostructure. The increase of sheet carrier density with the increase of Al content has been observed. A high mobility at room temperature of 2105 cm2/V s with a sheet carrier density of n s = 1.10 × 1013 cm-2, for a 26% Al-content AlGaN/GaN heterostructure has been obtained, which is approaching state-of-the-art for HEMT grown on SiC. Sheet resistance as low as 274 ?/? has also been achieved.

Ding, Guojian; Guo, Liwei; Xing, Zhigang; Chen, Yao; Xu, Peiqiang; Jia, Haiqiang; Zhou, Junming; Chen, Hong

2010-01-01

325

Anodic behavior of Al and the alloys Al-In and Al-In-Ga in aluminum-air batteries  

Microsoft Academic Search

The anodic behavior of aluminum and the alloys Al-In and Al-In-Ga was tested under the operating conditions of aluminum-air batteries. The tests were conducted in an aqueous solution of 2 M NaCl, and the results obtained were compared with the results obtained from a special test of these alloys as the anode in a standard electrochemical cell. Significant results and

D. M. Drazic; A. R. Despic; S. K. Zecevic

1979-01-01

326

Annealing effects on Al and Al-Si contacts with 3C-SiC  

NASA Astrophysics Data System (ADS)

Annealing effects on the current-voltage characteristics of Al and Al-Si contacts with n-type and p-type 3C-SiC films, epitaxially grown on Si by chemical vapor deposition, have been investigated. Al electrodes on n-type 3C-SiC show ohmic characteristics stable up to 400 C, but show distinct rectifying characteristics with annealing at 900 C. To the contrary, Al on p-type 3C-SiC clearly changes from non-ohmic into ohmic with annealing at 900 C. Al-Si alloys, which are usually used as ohmic electrodes for p-type SiC, show the same behavior as Al on n-type 3C-SiC. These results suggest the diffused Al atoms to yield a certain p-type layer.

Daimon, H.; Yamanaka, M.; Sakuma, E.; Misawa, S.; Yoshida, S.

1986-07-01

327

High-performance nonvolatile Al/AlOx/CdTe:Sb nanowire memory device  

NASA Astrophysics Data System (ADS)

Here we demonstrate a room temperature processed nonvolatile memory device based on an Al/AlOx/CdTe:Sb nanowire (NW) heterojunction. Electrical analysis shows an echelon hysteresis composed of a high-resistance state (HRS) and a low-resistance state (LRS), which can allow it to write and erase data from the device. The conductance ratio is as high as 106, with a retention time of 3 × 104 s. Moreover, the SET voltages ranged from +6 to +8 V, whilst the RESET voltage ?0 V. In addition, flexible memory nano-devices on PET substrate with comparable switching performance at bending condition were fabricated. XPS analysis of the Al/AlOx/CdTe:Sb NW heterojunction after controlled Ar+ bombardment reveals that this memory behavior is associated with the presence of ultra-thin AlOx film. This Al/AlOx/CdTe:Sb NW heterojunction will open up opportunities for new memory devices with different configurations.

Xie, Chao; Nie, Biao; Zhu, Long; Zeng, Long-Hui; Yu, Yong-Qiang; Wang, Xian-He; Fang, Qun-Ling; Luo, Lin-Bao; Wu, Yu-Cheng

2013-09-01

328

Transition element modifications of Al-Li  

SciTech Connect

The development of aluminum-lithium metallurgy has led to alloys with unsurpassed combinations of density, specific strength, and specific modulus. This paper describes recent advances in the modification of aluminum-lithium binary alloys through additions of the Group IV-A transition metals (titanium, zirconium, and hafnium). These elements lead to a duplex precipitation hardening behavior through the formation of Al3Li and Al3(TM,Li) (TM = transition element) which act as strengthening precipitates. The influence of the duplex structure on deformation mechanisms and the improvement of mechanical properties in these systems is illustrated by using results for the Al-Li-Zr system. 12 references.

Gayle, F.W.; Levoy, N.F.; Vandersande, J.B.

1987-05-01

329

Suspected variables among Al Sufi stars.  

NASA Astrophysics Data System (ADS)

In the tenth century Al Sufi compiled a catalogue of some 1100 stars. J.E. Gore, around 1900, wrote extensively on the magnitudes of these stars. On intercomparing them with a few other catalogues, Gore surmised that some 38 stars appeared to show secular variations. Here all the Al Sufi magnitudes have been compared with numerous additional sources, but smooth secular variations are not substantiated although some stars seem to have undergone comparatively sudden changes after about 1600. About 70 Al Sufi stars are now named or suscpected variable stars, but nearly all with amplitudes under 0.3 V.

Hoffleit, D.

330

Ni{sub 3}Al aluminide alloys  

SciTech Connect

This paper provides a brief review of the recent progress in research and development of Ni{sub 3}Al and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}Al alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}Al alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.

Liu, C.T.

1993-10-01

331

Al-induced faceting of Si(113)  

NASA Astrophysics Data System (ADS)

Adsorption of Al on a Si(113) substrate at elevated temperatures causes a faceting transition of the initially flat surface. The (113) surface decomposes into a quasi-periodic sequence of Al terminated (115)- and (112)-facets. The resulting surface morphology is characterized in-situ by reciprocal space maps obtained with in-situ spot profile analyzing low-energy electron diffraction and ex-situ atomic force microscopy. The periodicity length of the faceted surface increases with adsorption temperature from 7 nm at 650 °C to 80 nm at 800 °C. The stability of the Al terminated Si(112) surface is the driving force for the faceting transition.

Klein, Claudius; Heidmann, Inga; Nabbefeld, Tobias; Speckmann, Moritz; Schmidt, Thomas; Meyer zu Heringdorf, Frank-J.; Falta, Jens; Horn-von Hoegen, Michael

2013-12-01

332

Thermal diffusion in Ni/Al multilayer  

NASA Astrophysics Data System (ADS)

Two Ni/Al multilayers deposited by ion beam sputtering of nominal design [Ni(200A?)/Al(100A?)]×5 and [Ni(50A?)/Al(227A?)]×5 on Si substrates were annealed at 200°C. As-deposited and annealed samples were characterized by x-ray diffraction (XRD) and x-ray reflectometry (XRR). The effort was to study the path of alloying in the above two multilayers of same elements but of opposite stoichiometric ratio. We find distinct differences in alloying of these samples.

Swain, M.; Bhattacharya, D.; Singh, S.; Gupta, M.; Basu, S.

2013-02-01

333

Magnetic properties of FeAl2 and Fe2Al5  

NASA Astrophysics Data System (ADS)

We have investigated magnetic properties of the FeAl2 and Fe2Al5 intermetallic compounds. By measuring the zero-field-cooled and field-cooled static (dc) magnetic susceptibilities in low and high magnetic fields, the frequency-dependent (ac) susceptibility, the magnetization versus the magnetic field, and the thermoremanent magnetization time decay, we found that the magnetic structures of FeAl2 and Fe2Al5 are richer than those published so far in the literature. FeAl2 undergoes complex two-step magnetic ordering. At T ? 32 K, a magnetic phase transition (not yet specified) takes place in which a small fraction of the Fe spins participate, whereas at Tf2 ? 12 K, the majority spin fraction undergoes a spin-freezing transition to a spin glass phase. Fe2Al5 undergoes a transition to a spin glass phase at the spin freezing temperature Tf ? 3 K, which was not reported previously. The spin glass phase in Fe2Al5 is “soft” and fragile with respect to the external magnetic field and can only be observed in low magnetic fields below ˜100 Oe. The origins of the spin glass ordering in the FeAl2 and Fe2Al5 phases are randomness and frustration that are present on the Fe sublattices of both compounds. In FeAl2, the Fe spins are positioned randomly on the three mixed-occupation Al/Fe sites of the unit cell, whereas in Fe2Al5, partial occupation of the Fe-neighboring Al2 and Al3 atomic sites imposes different degrees of Fe moment screening by the electron cloud, resulting in a random distribution of the magnetic moment sizes. Geometric frustration because of positioning of the antiferromagnetically coupled Fe spins on triangles is present in both compounds as well.

Jagli?i?, Z.; Vrtnik, S.; Feuerbacher, M.; Dolinšek, J.

2011-06-01

334

Electroforming and Ohmic contacts in Al-Al2O3-Ag diodes  

NASA Astrophysics Data System (ADS)

Electroforming of metal-insulator-metal (MIM) diodes is a non-destructive dielectric breakdown process that changes the diode from its initial high resistance state (HRS) to a low resistance state (LRS). After electroforming, resistance switching memories (RSMs) use voltages to switch from HRS to LRS and back. Many MIM combinations are proposed for use in RSMs. In many cases conduction in the LRS is nearly temperature independent at low temperatures; an Ohmic contact with a barrier to electron injection of ~0 eV results from electroforming. Electroforming of Al-Al2O3-Ag diodes with amorphous anodic Al2O3 thicknesses between 12 and 41 nm has been studied. Two anodizing electrolytes have been used; 0.1 M ammonium pentaborate (bor-H2O) and a solution of 0.1 M of ammonium pentaborate per liter of ethylene glycol (bor-gly). Polarization of Al2O3 and negative charge in Al2O3 are much larger when Al2O3 is formed in bor-H2O solution than when Al is anodized in bor-gly solution. Electroforming of Al-Al2O3-Ag diodes results in an Ohmic contact at the Al-Al2O3 interface, voltage-controlled negative resistance (VCNR) in the current-voltage (I-V) characteristics, electroluminescence (EL), and electron emission into vacuum (EM) from filamentary conducting channels. Two distinct modes of electroforming occur for Al-Al2O3-Ag diodes. ?-forming occurs for 2.5 V <~ VS <~ 5 V, where VS is the applied voltage. It is characterized by an abrupt current jump with the simultaneous appearance of EL and EM. ?-forming occurs for VS >~ 7 V. I-V curves, EL, and EM develop gradually and are smaller than for ?-forming. Electroforming occurs more readily for diodes with Al2O3 formed in bor-H2O that have greater defect densities. Fully developed I-V curves have similar VCNR, EL, and EM after ?-forming or ?-forming. A model is proposed in which excited states of F-centers, oxygen vacancies in amorphous anodic Al2O3, form defect conduction bands. Electroforming that results in an Ohmic contact requires injection of positive charge at the Al-Al2O3 interface. ?-forming is the result of ionization of F-center recombination centers with energies that are close to the Al Fermi level. Hole injection by high-field ionization of valence band states of Al2O3 causes ?-forming.

Hickmott, T. W.

2012-03-01

335

Interdiffusion in Diffusion Couples: U-Mo v. Al and Al-Si  

SciTech Connect

Interdiffusion and microstructural development in the U-Mo-Al system was examined using solid-tosolid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, annealed at 600°C for 24 hours. The influence of Si alloying addition (up to 5 wt.%) in Al on the interdiffusion microstructural development was also examined using solid-to-solid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, Al-2wt.%Si, and Al-5wt.%Si annealed at 550°C up to 20 hours. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) were employed to examine the development of a very fine multiphase intermetallic layer. In ternary U-Mo-Al diffusion couples annealed at 600°C for 24 hours, interdiffusion microstructure varied of finely dispersed UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases while the average composition throughout the interdiffusion zone remained constant at approximately 80 at.% Al. Interdiffusion microstructure observed by SEM/TEM analyses and diffusion paths drawn from concentration profiles determined by EPMA appear to deviate from the assumption of “local thermodynamic equilibrium,” and suggest that interdiffusion occurs via supersaturated UAl4 followed by equilibrium transformation into UAl3, U6Mo4Al43, UAl4 and UMo2Al20 phases. Similar observation was made for U-Mo vs. Al diffusion couples annealed at 550°C. The addition of Si (up to 5 wt.%) in Al significantly reduced the thickness of the intermetallic layer by changing the constituent phases of the interdiffusion zone developed in U-Mo vs. Al-Si diffusion couples. Specifically, the formation of (U,Mo)(Al,Si)3 with relatively large solubility for Mo and Si, along with UMo2Al20 phases was observed along with disappearance of U6Mo4Al43 and UAl4 phases. Simplified understanding based on U-Al, U-Si, and Mo-Si binary phase diagrams is discussed in the light of the beneficial effect of Si alloying addition.

D. D. Keiser, Jr.; E. Perez; B. Yao; Y. H. Sohn

2009-11-01

336

Benefits for Military Veterans with ALS  

MedlinePLUS

... of Veterans More in this section: Visit our Wall of Honor How to Apply for Benefits ... | FAQ | Privacy Policy | Link Policy | RSS | Contact Us The ALS Association - 1275 K Street NW - Suite 250 - Washington, DC 20005 All content ...

337

76 FR 35938 - The Designation of Othman al-Ghamdi Also Known as Al Umairah al-Ghamdi, Also Known as Uthman al...  

Federal Register 2010, 2011, 2012, 2013

...as Othman Ahmed Othman al-Omirah as a Specially Designated Global Terrorist Pursuant to Section 1(b) of Executive Order 13224...nationals or the national security, foreign policy, or economy of the United States. Consistent with the determination...

2011-06-20

338

Serum and CSF immunological findings in ALS.  

PubMed

Serum and CSF immunological findings were analysed in 37 patients with amyotrophic lateral sclerosis (ALS). ALS patients had significantly higher mean values of serum IgG and complement component C4 and significantly lower mean value of total haemolytic titre of complement (THC) compared with normal controls. Incidence of immune complexes (ICs) was significantly higher in sera of ALS patients than in normal controls. There was no significant difference regarding mean serum levels of IgM, IgA, and complement components C3 and Factor B between patients and controls. The blood-brain barrier (BBB) damage was found in 46% of patients. Intrathecal IgG synthesis was detected in six patients (16%). These results support the hypothesis of immune system involvement in ALS. PMID:2017904

Apostolski, S; Nikoli?, J; Bugarski-Prokopljevi?, C; Mileti?, V; Pavlovi?, S; Filipovi?, S

1991-02-01

339

Al speciation in silicate glasses and melts  

NASA Astrophysics Data System (ADS)

The first human glasses were made 3500 BC. It was essentially sodo-lime silicate glass. To improve the chemical resistance, the thermal properties and increase the viscosity it is interesting to add aluminum in these silicates. But what is the speciation of the aluminum and how it varies according to the chemical composition and to the temperature? The aluminum appears essentially in four or five fold coordination in glasses and melts melted. The proportion of [5]Al varies according to the alkaline or to the earth-alkaline content and to the temperature. We shall present in a first part the influence of the network-modifier on the proportion of [5]Al and then we shall present some new results of absorption of high-temperature using NMR and XANES spectroscopy at the Al K-edge. Finally, from glass transition temperature measurements we propose to explain that [5]Al can be a new network former.

Neuville, Daniel; Florian, Pierre; Montouillout, Valérie; Le Losq, Charles; Massiot, Dominique

2010-05-01

340

Substitutional alloy of Ce and Al  

PubMed Central

The formation of substitutional alloys has been restricted to elements with similar atomic radii and electronegativity. Using high-pressure at 298 K, we synthesized a face-centered cubic disordered alloy of highly dissimilar elements (large Ce and small Al atoms) by compressing the Ce3Al intermetallic compound >15 GPa or the Ce3Al metallic glass >25 GPa. Synchrotron X-ray diffraction, Ce L3-edge absorption spectroscopy, and ab initio calculations revealed that the pressure-induced Kondo volume collapse and 4f electron delocalization of Ce reduced the differences between Ce and Al and brought them within the Hume-Rothery (HR) limit for substitutional alloying. The alloy remained after complete release of pressure, which was also accompanied by the transformation of Ce back to its ambient 4f electron localized state and reversal of the Kondo volume collapse, resulting in a non-HR alloy at ambient conditions.

Zeng, Qiao-Shi; Ding, Yang; Mao, Wendy L.; Luo, Wei; Blomqvist, Andreas; Ahuja, Rajeev; Yang, Wenge; Shu, Jinfu; Sinogeikin, Stas V.; Meng, Yue; Brewe, Dale L.; Jiang, Jian-Zhong; Mao, Ho-kwang

2009-01-01

341

Access to Iplex for Patients with ALS  

Center for Drug Evaluation (CDER)

... FDA Position on Allowing Patients with ALS Access to Iplex under an IND; FDA Summary of Controlled Clinical Data for Human IGF-1 in Treatment ... More results from www.fda.gov/drugs/resourcesforyou/healthprofessionals

342

Al Qaeda: Statements and Evolving Ideology.  

National Technical Information Service (NTIS)

Osama Bin Laden and the Al Qaeda terrorist network have conducted a sophisticated public relations and media campaign over the last 10 years. Terrorism analysts believe that these messages have been designed to elicit psychological reactions and communica...

C. M. Blanchard

2006-01-01

343

Al Qaeda: Statements and Evolving Ideology.  

National Technical Information Service (NTIS)

Osama Bin Laden and the Al Qaeda terrorist network have conducted a sophisticated public relations and media campaign over the last decade. Terrorism analysts believe that these messages have been designed to elicit psychological reactions and communicate...

C. M. Blanchard

2007-01-01

344

Al Qaeda: Statements and Evolving Ideology.  

National Technical Information Service (NTIS)

Al Qaeda leaders and affiliates have conducted sophisticated public relations and media campaigns since the mid-1990s. Terrorism analysts believe that these campaigns have been designed to elicit psychological reactions and communicate complex political m...

C. M. Blanchard

2007-01-01

345

Western Baldwin County, AL Grid Interconnection Project  

SciTech Connect

The Objective of this Project was to provide an additional supply of electricity to the affected portions of Baldwin County, AL through the purchase, installation, and operation of certain substation equipment.

Thomas DeBell

2011-09-30

346

Interdiffusion in the Mg-Al System and Intrinsic Diffusion in ?-Mg2Al3  

NASA Astrophysics Data System (ADS)

Solid-to-solid diffusion couples were assembled and annealed to examine the diffusion between pure Mg (99.96 pct) and Al (99.999 pct). Diffusion anneals were carried out at 573 K, 623 K and 673 K (300 °C, 350 °C and 400 °C) for 720, 360, and 240 hours, respectively. Optical and scanning electron microscopes were used to identify the formation of the intermetallic phases, ?-Mg17Al12, and ?-Mg2Al3, as well as the absence of the ?-Mg23Al30 in the diffusion couples. The thicknesses of the ?-Mg17Al12 and ?-Mg2Al3 phases were measured and the parabolic growth constants were calculated to determine the activation energies for growth. Concentration profiles were determined with electron microprobe analysis using pure elemental standards. Composition-dependent interdiffusion coefficients in Mg-solid solution, ?-Mg17Al12, ?-Mg2Al3, and Al-solid solutions were calculated based on the Boltzmann-Matano analysis. Integrated and average effective interdiffusion coefficients for each phase were also calculated, and the magnitude was the highest for the ?-Mg2Al3 phase, followed by ?-Mg17Al12, Al-solid solution, and Mg-solid solution. Intrinsic diffusion coefficients based on Huemann's analysis ( e.g., marker plane) were determined for the ~ Mg-62 at. pct Al in the ?-Mg2Al3 phase. Activation energies and the pre-exponential factors for the interdiffusion and intrinsic diffusion coefficients were calculated for the temperature range examined. The ?-Mg2Al3 phase was found to have the lowest activation energies for growth and interdiffusion among all four phases studied. At the marker location in the ?-Mg2Al3 phase, the intrinsic diffusion of Al was found to be faster than that of Mg. Extrapolations of the impurity diffusion coefficients in the terminal solid solutions were made and compared with the available self-diffusion and impurity diffusion data from the literature. Thermodynamic factor, tracer diffusion coefficients, and atomic mobilities at the marker plane composition were approximated using the available literature values of Mg activity in the ?-Mg2Al3 phase.

Brennan, Sarah; Bermudez, Katrina; Kulkarni, Nagraj S.; Sohn, Yongho

2012-11-01

347

Hydrogen diffusion in Al-Li alloys  

Microsoft Academic Search

The diffusion coefficients of hydrogen in binary Al-Li alloys containing 1,2, and 3 wt pct Li have been determined from desorption\\u000a curves of samples saturated with hydrogen at 473 to 873 K. Within this temperature range, the diffusivity of hydrogen in the\\u000a binary Al-Li alloys investigated has an Arrhenius-type temperature dependence and follows the equation of the general formD =

P. N. Anyalebechi

1990-01-01

348

Serrated yielding in Al-Li alloys  

Microsoft Academic Search

Serrated yielding (SY) during tensile testing has been observed in Al-Li alloys, both in the binary and the commercial quaternary alloys, in single crystal as well as polycrystalline materials. Serrated yielding is commonly explained by a dynamic strain aging (DSA) model developed by McCormick and van den Beukel. All the solute elements present in Al-Li alloys, viz., Mg, Cu and

S. Kumar; H. B. McShane

1993-01-01

349

AlN antiresonant layer ARROW waveguides  

Microsoft Academic Search

Aluminum Nitride (AlN) is a wide band gap III-V semiconductor material often used for optical applications due to its transparency and high refractive index. We have produced and characterized AlN thin films by reactive r.f. magnetron sputtering in different Ar-N2 atmospheres in order to verify the best gaseous concentration to be utilized as anti-resonant layer in ARROW waveguides. The corresponding

M. V. Pelegrini; D. O. Carvalho; M. I. Alayo; I. Pereyra

2010-01-01

350

Electric quadrupole moment of 31Al  

NASA Astrophysics Data System (ADS)

The electric quadrupole moment Q for the ground state of 31Al (I? = 5/2+) was measured by means of the ? ray-detected nuclear quadrupole resonance. A spin-polarized radioactive beam of 31Al was produced in the projectile-fragmentation reaction of a 40Ar beam on a 93Nb target. For the Q moment measurement, we developed a new radio-frequency application system to induce the spin reversal.

Nagae, D.; Ueno, H.; Kameda, D.; Takemura, M.; Asahi, K.; Takase, K.; Yoshimi, A.; Sugimoto, T.; Shimada, K.; Nagatomo, T.; Uchida, M.; Arai, T.; Inoue, T.; Kagami, S.; Hatakeyama, N.; Murata, J.; Kawamura, H.; Narita, K.

2008-10-01

351

Transition element modifications of Al-Li  

Microsoft Academic Search

The development of aluminum-lithium metallurgy has led to alloys with unsurpassed combinations of density, specific strength, and specific modulus. This paper describes recent advances in the modification of aluminum-lithium binary alloys through additions of the Group IV-A transition metals (titanium, zirconium, and hafnium). These elements lead to a duplex precipitation hardening behavior through the formation of Al3Li and Al3(TM,Li) (TM

F. W. Gayle; N. F. Levoy; J. B. Vandersande

1987-01-01

352

Sprachlich-kulturelle Heterogenität als Unterrichtsbedingung  

Microsoft Academic Search

Sprachlich-kulturelle Heterogenität in Bildungseinrichtungen ist seit mehr als drei Jahrzehnten eine Realität, die erst in\\u000a den letzten Jahren als eine fast durchgängige Rahmenbedingung von Schule und Unterricht zur Kenntnis genommen wird. Bereits\\u000a 30 % der Kinder zwischen sechs und zehn Jahren verfügen deutschlandweit über einen „Migrationshintergrund“ (Konsortium Bildungsberichterstattung\\u000a 2006, S. 143). Die größte Aufmerksamkeit erfährt seitdem die frühe Sprachförderung, da

Agi Schründer-Lenzen

353

Semiconducting Al transition-metal quasicrystals  

NASA Astrophysics Data System (ADS)

We report on a class of icosahedral aluminum transition-metal (Al-TM) alloys with true semiconducting behavior. Our description of the structure of these icosahedral quasicrystals is based on the six-dimensional Katz-Gratias-Boudard (KGB) model of the face-centered-icosahedral (fci) quasicrystal and its rational approximants. The shell structure of the atomic surfaces in perpendicular space defines the chemical order of aluminum and transition-metal (TM) atoms leading to semiconducting transport properties. In transition-metal aluminides the hybridization between the Al(s,p) and transition-metal d orbitals is responsible for the formation of a semiconducting gap in the electronic spectrum. We have analyzed the electronic charge distribution and observed an enhanced charge density along the Al-TM bonds that is characteristic of covalent bonding. The existence of an energy gap in the electronic spectrum at or in the vicinity of the Fermi level is explicitly demonstrated for several low-order approximants in the hierarchy of Fibonacci approximants which converges to the icosahedral quasicrystals of the fci class, to which also the i-AlPdRe belongs. We predict existence of truly semiconducting quasicrystalline 1/1-approximants. Our results also lead to the prediction of the existence of new semiconducting quasicrystals with specified Al-TM compositions. The possibility of the existence of a semiconducting band gap suggests an explanation for the anomalously high resistivity of the icosahedral AlPdRe quasicrystals. We demonstrate that substitutional defects violating the ideal Al-TM ordering predicted by the KGB model lead to the formation of localized states in the band gap. A real sample of i-AlPdRe thus seems to be a semiconductor with a band gap filled by the localized states.

Kraj?í, M.; Hafner, J.

2003-10-01

354

17th Annual ALS Users' Association Meeting  

SciTech Connect

It's not exactly Russian roulette, but scheduling October events outdoors is not risk-free, even in usually sunny California. An overflow crowd of more than 400 registered users, ALS staff, and vendors enjoyed a full indoor program featuring science highlights and workshops spread over two and a half days from October 18 to October 20. However, a major storm, heralding the onset of the San Francisco Bay Area rainy season, posed a few weather challenges for the events on the ALS patio.

Robinson, Art; Tamura, Lori

2004-11-29

355

Nature and Causality According to Al Bakillani  

Microsoft Academic Search

In this paper we expose the opinion of Al-Bakillani in respect to the question whether the world can be created naturally without an external cause. This opinion is fundamental because it forms the basis of the Ash'arites opinion on the subject of natural causality. For this reason we studied the three main versions of the problem as presented by al-Bakillani,

M. B. Altaie

356

Chronoamperometric studies of pitting corrosion of Al and (Al–Si) alloys by halide ions in neutral sulphate solutions  

Microsoft Academic Search

The pitting corrosion of Al, (Al+6%Si), and (Al+18%Si) alloys in neutral 0.50 M Na2SO4 solution in the absence and presence of NaCl, NaBr and NaI under the influence of various experimental variables has been studied by using potentiodynamic and chronoamperometric techniques. The results showed that the pitting corrosion resistance of the three Al samples decreases in the order: (Al+18%Si)>(Al+6%Si)>Al. The

Sayed S Abdel Rehim; Hamdi H Hassan; Mohammed A Amin

2004-01-01

357

Potential utilization of guar gum industrial waste in vermicompost production  

Microsoft Academic Search

Recycling of guar gum industrial waste through vermitechnology was studied under laboratory conditions by using composting earthworm Perionyx excavatus (Perrier). Three different combination of guar gum industrial waste namely guar gum industrial waste:cow dung:saw dust in 40:30:30 ratio (T1), guar gum industrial waste:cow dung:saw dust in 60:20:20 ratio (T2), and guar gum industrial waste:cow dung:saw dust in 75:15:10 ratio (T3)

Surendra Suthar

2006-01-01

358

Formation of Al3Ti/Mg composite by powder metallurgy of Mg Al Ti system  

NASA Astrophysics Data System (ADS)

An in situ titanium trialuminide (Al3Ti)-particle-reinforced magnesium matrix composite has been successfully fabricated by the powder metallurgy of a Mg-Al-Ti system. The reaction processes and formation mechanism for synthesizing the composite were studied by differential scanning calorimetry (DSC), x-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Al3Ti particles are found to be synthesized in situ in the Mg alloy matrix. During the reaction sintering of the Mg-Al-Ti system, Al3Ti particles are formed through the reaction of liquid Al with as-dissolved Ti around the Ti particles. The formed intermetallic particles accumulate at the original sites of the Ti particles. As sintering time increases, the accumulated intermetallic particles disperse and reach a relatively homogeneous distribution in the matrix. It is found that the reaction process of the Mg-Al-Ti system is almost the same as that of the Al-Ti system. Mg also acts as a catalytic agent and a diluent in the reactions and shifts the reactions of Al and Ti to lower temperatures. An additional amount of Al is required for eliminating residual Ti and solid-solution strengthening of the Mg matrix.

Yang, Zi R.; Wang, Shu Qi; Cui, Xiang H.; Zhao, Yu T.; Gao, Ming J.; Wei, Min X.

2008-07-01

359

Magnetism in Fe4Al13 and related FeAl intermetallics  

NASA Astrophysics Data System (ADS)

We report the results of an experimental study of FeAl alloys, including Fe4Al13, FeAl2 and Fe2Al5. By using NMR, dc magnetic susceptibility, and specific heat, we found that Fe4Al13 and Fe2Al5 are non-magnetic with some dilute magnetic moments, while FeAl2 can be characterized as a concentrated local moment system. Fe4Al13 is a decagonal quasicrystal approximant with 102 atoms in its unit cell. The ^27Al NMR spin-lattice relaxation indicates a very narrow pseudogap in the electronic density of states [g(E)] in the vicinity of the Fermi energy. The observations could be fit assuming a parabolic variation of g(E), consistent with observations in other quasicrystals and approximants. NMR lineshape measurements also agree with this analysis, and show that the system is dilute-magnetic, in strong contrast to the FeAl2 ordered intermetallic. We use specific heat to analyze the dilute moment density. This work was supported by the Robert A. Welch Foundation, Grant No. A-1526, by the National Science Foundation (DMR-0103455), and by Texas A&M University through the Telecommunications and Informatics Task Force.

Chi, Ji; Li, Yang; Gou, Weiping; Goruganti, V.; Rathnayaka, K. D. D.; Ross, Joseph H., Jr.

2006-03-01

360

Modeling of precipitation in Al alloys  

SciTech Connect

Objective was the development of a computational model of precipitation from a supersaturated alloy solid solution. The model is based on the formalism of chemical-reaction-rate theory combined with classical descriptions of precipitate thermodynamic properties and a mean-field treatment of diffusion-limited growht and coarsening. For the case of precipitation of Al{sub 3}Sc in supersaturated Al-Sc alloys, it is demonstrated how the model can be used to calculate number densities and size distributions of precipitates as a function of aging time and temperature, including effects of continuous cooling and thermally generated point defects. Application of the model to a specific alloy system requires knowledge of diffusion data, point defect energetics, and thermodynamic properties for bulk phases and interphase interfaces. For interfaces and point defects, thermodynamic data can be difficult to measure and reliable values of defect free energies are often unavailable. For this reason, part of the efforts were devoted to applying semiempirical and first-principles atomistic techniques to the calculation of interfacial and point-defect thermodynamic properties. This report discusses applications for interphase interfaces in the Al-Ag, Al-Sc, and Al-Li alloy systems. We also describe atomistic work aimed at understanding the energetics of vacancy clusters in Al. These clusters serve as sinks for isolated vacancies during aging and their growth can lead to more complex defects, such as dislocation loops, that act as heterogeneous nucleation sites.

Asta, M.; Foiles, S.M.; Wolfer, W.G. [Sandia National Labs., Livermore, CA (United States)] [and others

1996-10-01

361

Differential corticospinal tract degeneration in homozygous 'D90A' SOD-1 ALS and sporadic ALS  

PubMed Central

Background The homogeneous genotype and stereotyped phenotype of a unique familial form of amyotrophic lateral sclerosis (ALS) (patients homozygous for aspartate-to-alanine mutations in codon 90 (homD90A) superoxide dismutase 1) provides an ideal model for studying genotype/phenotype interactions and pathological features compared with heterogeneous apparently sporadic ALS. The authors aimed to use diffusion tensor tractography to quantify and compare changes in the intracerebral corticospinal tracts of patients with both forms of ALS, building on previous work using whole-brain voxelwise group analysis. Method 21 sporadic ALS patients, seven homD90A patients and 20 healthy controls underwent 1.5?T diffusion tensor MRI. Patients were assessed using ‘upper motor neuron burden,’ El Escorial and ALSFR-R scales. The intracranial corticospinal tract was assessed using diffusion tensor tractography measures of fractional anisotropy (FA), mean diffusivity, and radial and axial diffusivity obtained from its entire length. Results Corticospinal tract FA was reduced in sporadic ALS patients compared with both homD90A ALS patients and controls. The diffusion measures in sporadic ALS patients were consistent with anterograde (Wallerian) degeneration of the corticospinal tracts. In sporadic ALS, corticospinal tract FA was related to clinical measures. Despite a similar degree of clinical upper motor neuron dysfunction and disability in homD90A ALS patients compared with sporadic ALS, there were no abnormalities in corticospinal tract diffusion measures compared with controls. Conclusions Diffusion tensor tractography has shown axonal degeneration within the intracerebral portion of the corticospinal tract in sporadic ALS patients, but not those with a homogeneous form of familial ALS. This suggests significant genotypic influences on the phenotype of ALS and may provide clues to slower progression of disease in homD90A patients.

Blain, C R V; Brunton, S; Williams, V C; Leemans, A; Turner, M R; Andersen, P M; Catani, M; Stanton, B R; Ganesalingham, J; Jones, D K; Williams, S C R; Leigh, P N

2011-01-01

362

Oxidation of Ni-Rich Ni-Al Intermetallics.  

National Technical Information Service (NTIS)

The oxidation of Ni-Al intermetallic alloys in the beta-NiAl phase field and in the two phase beta-NiAl/gamma'-Ni3Al phase field has been studied between 1000 and 1400 C. The stoichiometric beta-NiAl alloy doped with Zr was superior to other alloy composi...

J. Doychak J. L. Smialek C. A. Barrett

1988-01-01

363

Optical gain characteristics of non-polar Al-rich AlGaN/AlN quantum well structures  

NASA Astrophysics Data System (ADS)

Optical properties of non-polar Al-rich AlGaN/AlN quantum well (QW) structures were investigated using the multiband effective-mass theory and non-Markovian optical model with the many-body effect. These results are compared with those of the c-plane, i.e., the (0001)-oriented QW structures. The theoretical PL transition wavelength is found to agree well with the experimental result. The optical gain for the x'-polarization is much larger than that for the y'-polarization because the optical matrix element for the x'-polarization is larger than for the y'-polarization. The x'-direction in the non-poalr plane corresponds to c-axis direction. Also, the optical gain for the x'-polarization is shown to decrease with increasing Al composition. This is mainly attribute to the fact that the optical matrix element is decreased due to the reduction in the electron-hole overlap for QW structures with higher Al contents.

Park, Seoung-Hwan

2011-09-01

364

Mechanical properties of Ni{sub 3}Al and FeAl: Recent developments  

SciTech Connect

Recent developments in the understanding of the ductility and fracture behavior of Ni{sub 3}Al and FeAl are reviewed. Both intrinsic factors (e.g., alloy stoichiometry), and extrinsic factors (e.g., environment) have been shown to affect their mechanical properties. Of all the recent developments, perhaps the most significant is the realization that Ni{sub 3}Al and FeAl are intrinsically ductile (at least on the Al-deficient side of stoichiometry); their brittleness when tested in ambient air is due mainly to environmental embrittlement. Another intriguing discovery is that boron embrittles Ni{sub 3}Al in gaseous hydrogen (until recently, B was though to have only beneficial, or at most neutral, effects). The authors review these and other recent discoveries and discuss, wherever possible, the underlying physical mechanisms giving rise to the observed mechanical behavior.

George, E.P.; Liu, C.T. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1997-08-01

365

Thermal Properties in the MgAl2O4-Al2O3 System  

SciTech Connect

Compositional effects on the thermal diffusivity in the MgAl2O4-Al2O3 system were studied. The lowest thermal diffusivity, 0.0258 +/-5% cm/s, was measured between 79.8 and 83.9 wt% Al2O3 quenched from various temperatures between 1500 and 1700C. All of the chemistries in this range extend past the solvus, but still form a singe super-saturated spinel solid solution, regardless of quenching tempeature. A super-saturated metastable solid solution region was observed at 1500, 1600, and 1700C extending to 83.9, 85.2, and 87.1 wt% Al2O3, respectively. Beyond 83.9% Al2O3 a significant increase in thermal diffusivity, 11.7%, was observed and its attributed to precipiation of Al2O3 through spinodal decomposition.

Wilkerson, Dr. Kelley R. [Missouri University of Science and Technology; Smith, Jeffrey D [ORNL; Hemrick, James Gordon [ORNL

2013-01-01

366

Tin/Al sub 2 O sub 3 /TiAlOn composite  

SciTech Connect

The present invention pertains to novel improved density ceramic composites of TiN/Al2O3/TiAlON in which there is no spinel and no AlN, but alpha-alumina, titanium nitride, and titanium aluminum oxynitride. In general, the improved density TiN/Al2O3/TiAlON ceramic composites of the invention are prepared by: adding aluminum isobutoxide (Al(O-iBu)3) to a refluxing mixture of deionized water and formic acid at elevated temperatures to obtain an aluminum sol; casting the slurry in molds; drying the cast material and calcining it at about 600 C; screening the calcined material to minus 200 mesh; pressing pellets at about 10 KPsi, isostatically pressing them at about 40 KPsi; and sintering the pellets below 1,700 C to obtain sintered bodies having densities greater than about 4.2 g/cc.

Han, K.

1990-04-02

367

Relationship between electrical conductivity and stress corrosion cracking susceptibility of Al 7075 and Al 7475 alloys  

SciTech Connect

A relationship between electrical conductivity and stress corrosion cracking (SCC) resistance of the 7,000-series Al-Zn-Mg alloys has been established, although only from the near-peak strength T6 temper to the overaged T73 tempered condition. The present work investigated whether this relationship exists for all periods of aging and for Al alloys with different compositions and grain structures. The materials studied were commercial 2-mm thick Al 7075 (Al-5.76% Zn-2.46% Mg-1.70% Cu-0.20% Cr-0.12% Fe-0.09% Si-0.06% Mn-0.04% Ti) and Al 7475 (Al-5.80% Zn-2.24% Mg-1.53% Cu-0.19% Cr-0.08% Fe-0.02% Si-0.01% Mn-0.02% Ti) alloy plates.

Tsai, T.C.; Chuang, T.H. [National Taiwan Univ., Taipei (Taiwan, Province of China). Inst. of Materials Science and Engineering

1996-06-01

368

Theoretical studies of Ni/sub 3/Al and NiAl with impurities  

SciTech Connect

Intermetallic compound has been extensively studied because of their superior properties in strength, low creep rate, and high melting point. But most of the systems have room temperature ductility problems, like Ll/sub 2/ and B2 compounds. Both Ll/sub 2/ Ni/sub 3/Al and B2 NiAl exhibit intergranular fracture mode. Understanding grain boundaries in these materials is of particular importance since intergranular fracture limits the applicability of these otherwise promising material. In an effort trying to understand the fracture mechanism, we have used embedded atom potentials to study the properties of Ni/sub 3/Al and NiAl. We also consider the effect of boron, sulfur, and nickel segregation on the strength of grain boundaries in Ni/sub 3/Al and NiAl. 22 refs., 2 figs.

Chen, S.P.; Voter, A.F.; Boring, A.M.; Albers, R.C.; Hay, P.J.

1988-01-01

369

60Co gamma radiation effect on AlGaN/AlN/GaN HEMT devices  

NASA Astrophysics Data System (ADS)

The testing techniques and experimental methods of the 60Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established. The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically, and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out. The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated, and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained.

Wang, Yan-Ping; Luo, Yin-Hong; Wang, Wei; Zhang, Ke-Ying; Guo, Hong-Xia; Guo, Xiao-Qiang; Wang, Yuan-Ming

2013-05-01

370

77 FR 73732 - In the Matter of Amendment of the Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa'al...  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF STATE [Public Notice 8104] In the Matter of Amendment of the Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa'al-Jihad, aka The Monotheism and Jihad Group, aka The al-Zarqawi Network, aka...

2012-12-11

371

Laser cladding NiCoCrAlY coating on Ti6Al4V  

Microsoft Academic Search

In order to improve wear resistance of titanium alloy, a process of laser cladding NiCoCrAlY coating on Ti-6Al-4V substrate with pre-placed NiCoCrAlY powder was studied. A good coating without cracks and pores was obtained in a proper laser process. The microstructure of the coating was examined using SEM and EDS. There is a metallurgical interface bonding between the coating and

Qingwu Meng; Lin Geng; Dingrui Ni

2005-01-01

372

Nucleation Effect of Ti6Al4V Powder on Al–Si Eutectic Alloy  

Microsoft Academic Search

In this research nucleation effect of Ti-6Al-4 V powder on grain size and tensile strength of Al-12.1% Si eutectic alloy was studied. Metal powder produced from Ti-6Al-4 V machining chips by meshes of 50 and 140 and weight percentages of 0.1, 0.15, 0.2, and 0.25 were used. The microstructure by mesh 50 with 0.15 wt% consists of grain with average size of 6 µm,

Zohair Sarajan

2009-01-01

373

A note on Wang et al's attack on Zhang et al's multiparty quantum secret sharing  

NASA Astrophysics Data System (ADS)

Recently, Wang et al (2008 Phys. Lett. A 373 65) proposed an attack on Zhang et al's (2007 Opt. Commun. 269 418) multiparty quantum secret sharing scheme, in which the first and the last agent are reported to be able to cooperatively eavesdrop on all the secret messages without being detected. In this paper, we show that in Wang et al's attack, on average no more than half the secret messages can be eavesdropped.

Gao, Gan

2012-08-01

374

Anodic Oxidation of Aluminum by Electron Tunneling through Al/Cadmium-Stearate/Al Structure  

NASA Astrophysics Data System (ADS)

The conduction of the monolayer Langmuir-Blodgett(LB) film consisting of Cadmium-Stearate(CdSt) may be explained by an electron tunneling process. The tunneling current through the Al/CdSt/Al sample showed a great decrease with time when a constant voltage was applied in air. Such a phenomenon seems to result from the growth of an Al2O3 layer by the anodic oxidation of the aluminum electrode enhanced by the electron tunneling.

Okazaki, Choichiro; Kuniyoshi, Shigekazu; Kudo, Kazuhiro; Tanaka, Kuniaki

1989-11-01

375

Tensile deformation behavior of a sub-micrometer Al 2O 3\\/6061Al composite  

Microsoft Academic Search

A 0.3?m Al2O3\\/6061Al composite with 33% volume fraction of Al2O3 was fabricated by the patented squeeze-casting technology. The tensile properties were studied, and the dynamic tensile deformation behavior was investigated by an in situ TEM tensile technique. The as-cast composite exhibits excellent tensile properties with a fracture strength of 504MPa, and the strength increases to 579MPa after a T6 treatment.

Qiang Zhang; Gaohui Wu; Longtao Jiang

2008-01-01

376

NMR measurements and hybridization behavior in Al_3Zr, Al_3Hf, and related intermetallics  

Microsoft Academic Search

We report ^27Al NMR measurements on aluminum-rich intermetallics, including the DO_23-structured alloys Al_3Zr and Al_3Hf, and related close-packed structures. We determined the quadrupole splittings and Knight shifts, giving site-dependent structural information. The Knight shift tensors indicate strong directional bonding in the DO_23 alloys, despite the modified close-pack structures. This is especially true for sites I and III. The non-zero asymmetry

Chin Shan Lue Ross Jr.

2001-01-01

377

Cryptanalysis of Khan et al.'s dynamic ID-based remote user authentication scheme  

Microsoft Academic Search

Recently, Khan et al. showed that Wang et al.'s dynamic ID-based remote user authentication scheme is not feasible for real-life implementations such as without preserving anonymity of a user during authentication, user cannot choose the password he\\/she wants, no provision for revocation of lost or stolen smart card, and can not provide session key agreement. Consequently, an improved version of

Chun-Ta Li; Chen-Ju Liu; Cheng-Chi Lee; Chin-Wen Lee

2010-01-01

378

Mechanism of Nonalloyed Al Ohmic Contacts to n-Type ZnO:Al Epitaxial Layer  

Microsoft Academic Search

The mechanism of Al ohmic contacts to n-type zinc oxide (ZnO:Al) epitaxial layer was investigated. The formation of an Al-ZnO interfacial phase at room temperature was responsible for the low specific resistivity (8± 0.3× 10-4 Omegacm2). The results of Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) depth profiles, and glancing angle X-ray diffraction (GXRD) indicate that an interfacial reaction

Han-Ki Kim; Tae-Yeon Seong; Koung-Kook Kim; Seoug-Ju Park; Young Soo Yoon; Ilesanmi Adesida

2004-01-01

379

Long range order and vacancy properties in Al-rich Fe{sub 3}Al and Fe{sub 3}Al(Cr) alloys  

SciTech Connect

Neutron powder diffraction measurements have been carried out in situ from room temperature to about 100 C in Fe28Al (28 at.% Al), Fe32.5Al (32.5 at.% Al) and Fe28Al15Cr (28 at.% Al, 5 at.% Cr) alloys. X-ray diffraction and TEM studies provided supporting information. The data were analyzed to obtain information about the temperature dependence of the DO{sub 3} and B2 long range order parameters, the location of the Cr atoms and their effect on the ordering energies, and on the vacancy formation and migration properties in Fe28Al and Fe32.5Al alloys. The location of the ternary alloying addition in DO{sub 3} and B2 ordered Al-rich Fe{sub 3}Al is shown to be consistent with considerations of interatomic bond energies.

Kim, S.M. [AECL, Chalk River, Ontario (Canada). Chalk River Labs.; Morris, D.G. [Univ. of Neuchatel (Switzerland). Inst. of Structural Metallurgy

1998-05-01

380

Theoretical and Experimental Study of Relaxations in Al3Ti and Al3Zr Ordered Phases  

NASA Astrophysics Data System (ADS)

The aim of the present investigation was to elucidate the role of structural relaxations in determining the relative stability of L12, D022, and D023 structures in Al3Ti and Al3Zr. This task was accomplished by a unique combination of total-energy electronic structure calculations and (for Al3Zr) high resolution neutron diffraction with Reitveld refinement. Calculated and measured atomic displacements are in excellent agreement. Local relaxation is found to be responsible for the stability of the D023 structure in Al3Zr, in agreement with experimental evidence.

Amador, C.; Hoyt, J. J.; Chakoumakos, B. C.; de Fontaine, D.

1995-06-01

381

Al-matrix composite materials reinforced by Al-Cu-Fe particles  

NASA Astrophysics Data System (ADS)

Al-matrix material composites were produced using hot isostatic pressing technique, starting with pure Al and icosahedral (i) Al-Cu-Fe powders. Depending on the processing temperature, the final reinforcement particles are either still of the initial i-phase or transformed into the tetragonal ?-Al00.70Cu0.20Fe0.10 crystalline phase. Compression tests performed in the temperature range 293K - 823K on the two types of composite, i.e. Al/i and Al/?, indicate that the flow stress of both composites is strongly temperature dependent and exhibit distinct regimes with increasing temperature. Differences exist between the two composites, in particul ar in yield stress values. In the low temperatureregime (T <= 570K), the yield stress of the Al/? composite is nearly 75% higher than that of the Al/i composite, while for T > 570K both composites exhibit similar yield stress values. The results are interpreted in terms of load transfer contribution between the matrix and the reinforcement particles and elementary dislocation mechanisms in the Al matrix.

Bonneville, J.; Laplanche, G.; Joulain, A.; Gauthier-Brunet, V.; Dubois, S.

2010-07-01

382

Annealing effects on Al and Al-Si contacts with 3C-SiC  

Microsoft Academic Search

Annealing effects on the current-voltage characteristics of Al and Al-Si contacts with n-type and p-type 3C-SiC films, epitaxially grown on Si by chemical vapor deposition, have been investigated. Al electrodes on n-type 3C-SiC show ohmic characteristics stable up to 400 C, but show distinct rectifying characteristics with annealing at 900 C. To the contrary, Al on p-type 3C-SiC clearly changes

Hiroshi Daimon; Mitsugu Yamanaka; Eiichiro Sakuma; Shunji Misawa; Sadafumi Yoshida

1986-01-01

383

Reactions of CO2 on solid and liquid Al100+.  

PubMed

The reactions of CO(2) on the Al(100)(+) cluster have been investigated as a function of cluster temperature (300-1100 K) and relative kinetic energy (0.2-10 eV). Two main products are observed at low cluster temperature: Al(100)O(+) (which is believed to result from a stripping reaction) and Al(100)CO(2)(+) from complex formation. As the cluster temperature is raised, both products dissociate by loss of Al(2)O. Al(100)O(+) forms Al(98)(+), while Al(100)CO(2)(+) forms Al(98)CO(+) and Al(96)C(+). In both cases, loss of Al(2)O turns-on above the melting temperature of Al(100)(+). This presumably occurs because the overall reaction leading to the loss of Al(2)O is significantly less endothermic for the liquid cluster than for the solid. PMID:22680973

Leslie, Katheryne L; Shinholt, Deven; Jarrold, Martin F

2012-06-11

384

77 FR 67689 - Fidelity Aberdeen Street Trust, et al.;  

Federal Register 2010, 2011, 2012, 2013

...812-13731] Fidelity Aberdeen Street Trust, et al.; Notice of Application November 6...1\\ Colchester Street Trust, et al., Investment Company Act Release Nos...amending, Colchester Street Trust, et al., Investment Company Act Release...

2012-11-13

385

75 FR 57846 - Amendment of Class E Airspace; Brewton, AL  

Federal Register 2010, 2011, 2012, 2013

...Amendment of Class E Airspace; Brewton, AL AGENCY: Federal Aviation Administration...at Brewton Municipal Airport, Brewton, AL, by updating the geographic coordinates...of Brewton Municipal Airport, Brewton, AL. This action makes the adjustment....

2010-09-23

386

Effect of elemental powder blending ratio on combustion foaming behavior of porous Al–Ti intermetallics and Al 3Ti\\/Al composites  

Microsoft Academic Search

Porous Al–Ti intermetallics and Al3Ti\\/Al composites were fabricated by combustion foaming process. Fundamentally, aluminum and titanium powders were blended (Al\\/Ti mole blending ratios ranging from 0.33 to 10.0). Additionally, boron carbide (B4C) powder was blended as exothermic agent since the heat of TiC and TiB2 formation is much higher than those of Al–Ti intermetallics. The blended powder compact was heated

Makoto Kobashi; Norio Inoguchi; Naoyuki Kanetake

2010-01-01

387

Regulation of Tomato golden mosaic virus AL2 and AL3 gene expression by a conserved upstream open reading frame.  

PubMed

A translational regulatory mechanism for Tomato golden mosaic virus (TGMV) complementary-sense gene expression has been characterized. TGMV transcribes two mRNAs, AL-1935 and AL-1629 transcripts, both of which contain the AL2 and AL3 open reading frames. However, AL2 is only expressed from AL-1629 whereas AL3 is expressed from both. Three AUG translation initiation codons are located upstream of both the AL2 and AL3 coding regions, within the 5'-untranslated region (UTR) of the AL-1935 transcript. Translation can initiate at the first AUG, specifying the C-terminal 122 amino acids of the AL1 protein (cAL1). Initiation of translation at this AUG is inhibitory for the downstream expression of both AL2 and AL3. This is most likely due to the terminator codon of cAL1 being positioned after the AUG initiation codon for the AL2 ORF. The mechanism by which AL3 is expressed from AL-1935 is currently unknown but a gap between the cAL1 termination codon and the start of AL3 suggests that it may involve reinitiation and/or internal initiation. In contrast, expression of AL3 from AL-1629 most likely occurs via leaky ribosome scanning since the AL3 initiation codon occurs before the terminator codon of AL2. Mutation of the AUG encoding cAL1 in the curtovirus, Spinach curly top virus, leads to increased infectivity as measured by a shorter latent period. Together this suggests that geminiviruses use a post-translational regulatory mechanism to regulate the synthesis of viral proteins important for replication and suppression of host defenses. PMID:19012941

Shung, Chia-Yi; Sunter, Garry

2008-11-14

388

Machining performance of Ti–Al–Si–N coated inserts  

Microsoft Academic Search

Ti–Al–Si–N quaternary coating has recently been developed for industrial applications due to its excellent machining performance. Here, we present a comparative research on Ti–Al–N single layer, Ti–Al–Si–N single layer, TiAlN–TiAlSiN bilayer and TiAlN\\/TiAlSiN multilayer coatings deposited onto cemented carbide substrates by cathodic arc evaporation. The incorporation of Si into the Ti–Al–N coating results in an increase in hardness and thermal

Li Chen; She Q. Wang; Yong Du; Shu Z. Zhou; Tie Gang; Ji C. Fen; Ke K. Chang; Yi W. Li; Xiang Xiong

2010-01-01

389

Stress granules as crucibles of ALS pathogenesis  

PubMed Central

Amyotrophic lateral sclerosis (ALS) is a fatal human neurodegenerative disease affecting primarily motor neurons. Two RNA-binding proteins, TDP-43 and FUS, aggregate in the degenerating motor neurons of ALS patients, and mutations in the genes encoding these proteins cause some forms of ALS. TDP-43 and FUS and several related RNA-binding proteins harbor aggregation-promoting prion-like domains that allow them to rapidly self-associate. This property is critical for the formation and dynamics of cellular ribonucleoprotein granules, the crucibles of RNA metabolism and homeostasis. Recent work connecting TDP-43 and FUS to stress granules has suggested how this cellular pathway, which involves protein aggregation as part of its normal function, might be coopted during disease pathogenesis.

King, Oliver D.

2013-01-01

390

The mechanical properties of FeAl  

SciTech Connect

Only in the last few years has progress been made in obtaining reproducible mechanical properties data for FeAl. Two sets of observations are the foundation of this progress. The first is that the large vacancy concentrations that exist in FeAl at high temperature are easily retained at low temperature and that these strongly affect the low-temperature mechanical properties. The second is that RT ductility is adversely affected by water vapor. Purpose of this paper is not to present a comprehensive overview of the mechanical properties of FeAl but rather to highlight our understanding of key phenomena and to show how an understanding of the factors which control the yield strength and fracture behavior has followed the discovery of the above two effects. 87 refs, 9 figs.

Baker, I. [Dartmouth Coll., Hanover, NH (United States); George, E.P. [Oak Ridge National Lab., TN (United States)

1996-12-31

391

Boron strengthening in FeAl  

SciTech Connect

The effect of boron on the strength of B2-structured FeAl is considered as a function of composition, grain size and temperature. Boron does not affect the concentrations of antisite atoms or vacancies present, with the former increasing and the latter decreasing with increasing deviation from the stoichiometric composition. When vacancies are absent, the strength increase per at. % B per unit lattice strain, {Delta}{sigma}/({Delta}c x {epsilon}) increases with increasing aluminum concentration, but when vacancies are present (>45 at. % Al), {Delta}{sigma}/({Delta}c x {epsilon}) decreases again. Boron increases grain size strengthening in FeAl. B strengthening is roughly independent of temperature up to the yield strength peak but above the point, when diffusion-assisted deformation occurs, boron strengthening increases dramatically.

Baker, I.; Li, X.; Xiao, H.; Klein, O.; Nelson, C. [Dartmouth Coll., Hanover, NH (United States). Thayer School of Engineering; Carleton, R.L.; George, E.P. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1998-11-01

392

Stress granules as crucibles of ALS pathogenesis.  

PubMed

Amyotrophic lateral sclerosis (ALS) is a fatal human neurodegenerative disease affecting primarily motor neurons. Two RNA-binding proteins, TDP-43 and FUS, aggregate in the degenerating motor neurons of ALS patients, and mutations in the genes encoding these proteins cause some forms of ALS. TDP-43 and FUS and several related RNA-binding proteins harbor aggregation-promoting prion-like domains that allow them to rapidly self-associate. This property is critical for the formation and dynamics of cellular ribonucleoprotein granules, the crucibles of RNA metabolism and homeostasis. Recent work connecting TDP-43 and FUS to stress granules has suggested how this cellular pathway, which involves protein aggregation as part of its normal function, might be coopted during disease pathogenesis. PMID:23629963

Li, Yun R; King, Oliver D; Shorter, James; Gitler, Aaron D

2013-04-29

393

Influence of Al 2O 3 particulate on the aging response of A356 Al-based composites  

Microsoft Academic Search

A356 Al alloy reinforced with Al2O3 particulates of different sizes (25?m angular or 40?m microsphere) and volume fractions (5, 10 and 20vol.%) was prepared using vortex method. The influence of Al2O3 particulates on the precipitation and hardening behavior of the A356 Al–Al2O3 composites was studied. It was found that the MgAl2O4 spinel formed at the interface led to Mg depletion

A. Daoud; W. Reif

2002-01-01

394

Layered growth of the quasicrystalline decagonal Al3Pd phase in Al\\/Pd lateral diffusion couples  

Microsoft Academic Search

The solid-state reaction in an Al\\/Pd lateral diffusion couple starts with the growth of the crystalline Al3Pd2(delta) phase. When the growth of Al3Pd2 reaches its critical length, the quasicrystalline decagonal Al3Pd(gamma') phase starts to grow and both the Al3Pd2 and Al3Pd phases continue to grow afterwards. We have fitted this simultaneous growth with a recently proposed model of kinetic suppression

B. Blanpain; J. W. Mayer; Joyce C. Liu; K. N. Tu

1990-01-01

395

The evaluation and measurement of AlGaN epitaxial layer with high Al mole fraction  

NASA Astrophysics Data System (ADS)

The epitaxial layer quality of AlxGa1-xN (x>0.6) on sapphire substrate grown by metal organic chemical vapor deposition (MOCVD) needs to be further improved. In this paper, we evaluated the properties of defects, lattice mismatch between epitaxial layer and substrate, crystal quality and conductivity for these high Al mole fraction materials from the viewpoint of fabricating high performance solar blind detectors by comprehensive utilizing various undamaged measurements. The measurement of transmission spectrum was used to evaluate the absorption edge, band gap, mole fraction of Al content, hetero-epitaxial interface, and transmissivity in the ultraviolet spectral range. X-ray diffraction (XRD) was used to measure the component of the AlGaN material, uniformity of the material and crystal quality. The conductivity of the surface layer of the AlGaN film material was obtained by using high precision current-voltage curve measurement. In short, the material quality, optical and electrical properties, and uniformity for high Al mole fraction AlGaN epitaxial layers were qualitatively or quantitatively measured and analyzed. These works lay the foundation for manufacturing high performance solar blind ultraviolet detectors based on high Al mole fraction AlGaN epitaxial materials on sapphire substrate.

Meng, Zhao; Yu, Libo; Li, Xiao; Liu, Qibin; Duan, Huiqiang; Yu, Chenhui; Chen, Changqing

2009-08-01

396

Spark plasma and microwave sintering of Al6061 and Al2124 alloys  

NASA Astrophysics Data System (ADS)

Despite the importance of aluminum alloys as candidate materials for applications in aerospace and automotive industries, very little work has been published on spark plasma and microwave processing of aluminum alloys. In the present work, the possibility was explored to process Al2124 and Al6061 alloys by spark plasma and microwave sintering techniques, and the microstructures and properties were compared. The alloys were sintered for 20 min at 400, 450, and 500°C. It is found that compared to microwave sintering, spark plasma sintering is an effective way to obtain homogenous, dense, and hard alloys. Fully dense (100%) Al6061 and Al2124 alloys were obtained by spark plasma sintering for 20 min at 450 and 500°C, respectively. Maximum relative densities were achieved for Al6061 (92.52%) and Al2124 (93.52%) alloys by microwave sintering at 500°C for 20 min. The Vickers microhardness of spark plasma sintered samples increases with the increase of sintering temperature from 400 to 500°C, and reaches the values of Hv 70.16 and Hv 117.10 for Al6061 and Al2124 alloys, respectively. For microwave sintered samples, the microhardness increases with the increase of sintering temperature from 400 to 450°C, and then decreases with the further increase of sintering temperature to 500°C.

Saheb, Nouari

2013-02-01

397

Combustion Synthesis Reactions in Cold-Rolled Ni/Al and Ti/Al Multilayers  

NASA Astrophysics Data System (ADS)

In this article, a cold rolling method was developed to fabricate Ni/Al and Ti/Al multilayer foils, and the combustion synthesis reactions in the cold-rolled foils were investigated. Combustion synthesis reactions were initiated by heating one end of the cold-rolled foil in a flame for several seconds. The Ni/Al foils went through three reaction stages. The first reaction stage was a displacement of reaction zone with Al3Ni as the reaction product. During the second stage, the part of the foil in the flame underwent thermal explosion. In the last stage, the heat released by thermal explosion triggered a self-propagating high-temperature synthesis (SHS) reaction across the foil that resulted in the formation of AlNi. In contrast, the Ti/Al foils experienced only two reaction stages. First, a displacement of the reaction zone propagated across the foil with formation of Al3Ti at the Ti/Al interface. Then a thermal explosion reaction occurred in the part of foil that was heated in the flame, resulting in many different phases in the reacted foil.

Qiu, Xiaotun; Liu, Ranran; Guo, Shengmin; Graeter, Jesse Harris; Kecskes, Laszlo; Wang, Jiaping

2009-07-01

398

On Approaches to Learning versus Learning Styles: A Reply to Duff et al.'s Comment  

Microsoft Academic Search

The Comment of Duff, Dobie and Guo (forthcoming) offers variable usefulness. At its best, Duff et al.'s Comment makes an earnest attempt to promote dialogue and debate. For example, their Comment offers new ways to reconceptualize our two papers, and further offers challenges to how the research was motivated and executed. As such, their Comment provides glimpses of the healthy

Ralph W. Adler; Rosalind H. Whiting; Kate Wynn-Williams

2008-01-01

399

Research Note: Hassan al-Turabi, Osama bin Laden, and Al Qaeda in Sudan  

Microsoft Academic Search

This research note explores the events and circumstances surrounding Osama bin Laden's stay in Sudan from 1991 to 1996. In particular, it discusses the role that the Sudanese politician, Hassan al-Turabi may have played in the development of bin Laden and al Qaeda. It draws particular attention to the role of the Popular Arab and Islamic Congress (PAIC) in the

Max Taylor; Mohamed E. Elbushra

2006-01-01

400

Al Qaeda and al Qaeda in the Arabian Peninsula: Inspired, Homegrown Terrorism in the United States  

Microsoft Academic Search

This article analyzes a facet of the phenomenon of al Qaeda (AQ) and al Qaeda in the Arabian Peninsula (AQAP)-inspired terrorism on U.S. soil. The twenty case studies addressed in this piece are illustrative of the nature of the current threat as well as foreshadows future risks of transnational jihad.

Dean C. Alexander

2011-01-01

401

Fabrication and Mechanical Properties of Ni3 Al--Al2 O3 Composites.  

National Technical Information Service (NTIS)

The objective of this study is to develop a metal-matrix composite based on the intermetallic alloy Ni3 Al reinforced with Al2 O3 fibers, with improved high-temperature strength and lower density compared to the matrix material. This paper summarizes resu...

C. G. McKamey G. L. Povirk J. A. Horton T. N. Tiegs E. K. Ohriner

1988-01-01

402

Electronic circuits having NiAl and Ni.sub.3 Al substrates  

DOEpatents

An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)

1999-01-01

403

Powder size effect on cell morphology of combustion synthesized porous Al 3Ti\\/Al composite  

Microsoft Academic Search

Porous Al3Ti\\/Al composites were fabricated by the combustion foaming process and the effect of elemental powder size on porosity and cell morphology was investigated. High porosity was obtained by using the small titanium powders. Pores also became larger and more spherical by using the small titanium powders. Pore size became smaller and porosity became higher by decreasing the aluminum powder

Makoto Kobashi; Norio Inoguchi; Naoyuki Kanetake

2010-01-01

404

Nb3Al Development for HEP Applications  

SciTech Connect

Recent developments in Nb3Al strand for HEP applications are presented and discussed. The present state of available precursor is detailed. Two routes have been shown to lead to successful construction of MF NbAl composite wires. An extrusion method has so far produced the highest filament counts and smallest filament diameters, but requires more processing steps. A direct restack and draw approach has also been demonstrated which minimizes the number of processing steps while still leading to a high performance conductor. This latter route also allows for a lower cost per billet, potentially allowing the exploration of more process parameters.

Sumption, M.D.; Buta, F.; Collings, E.W. [Laboratories for Applied Superconductivity and Magnetism (LASM), MSE Dept, The Ohio State University, Columbus, OH 43210 (United States); Tomsic, M.; Phillips, J.; McFadden, K. [Hyper Tech Research Inc., Troy, OH 45373 (United States); Wu, X

2004-06-28

405

Surface phonon polariton characteristics of In(0.04)Al(0.06)Ga(0.90)N/AlN/Al(2)O(3) heterostructure.  

PubMed

Surface phonon polariton (SPP) characteristics of In(0.04)Al(0.06)Ga(0.90)N/AlN/Al(2)O(3) heterostructure are investigated by means of p-polarized infrared (IR) attenuated total reflection spectroscopy. Two absorption dips corresponding to In(0.04)Al(0.06)Ga(0.90)N SPP modes are observed. In addition, two prominent dips and one relatively weak and broad dip corresponding to the Al(2)O(3) SPP mode, In(0.04)Al(0.06)Ga(0.90)N/Al(2)O(3) interface mode, and Al(2)O(3) bulk polariton mode, respectively, are clearly seen. No surface mode feature originating from the AlN layer is observed because it is too thin. Overall, the observations are in good agreement with the theoretical predictions. PMID:20588890

Ng, S S; Lee, S C; Bakhori, S K Mohd; Hassan, Z; Abu Hassan, H; Yakovlev, V A; Novikova, N N; Vinogradov, E A

2010-05-10

406

AlN homoepitaxial growth on sublimation-AlN substrate by low-pressure HVPE  

NASA Astrophysics Data System (ADS)

Crack-free thick AlN layers with low impurity concentrations were grown on free-standing AlN substrates fabricated by a sublimation method. Cracks due to tensile stresses were generated in the overgrowth layer when using on-axis AlN (0 0 0 1) substrates, as indicated by Raman scattering spectroscopy. In contrast, cracks were not generated when using 5° off-angle AlN (0 0 0 1) substrates. High crystalline quality was indicated by X-ray rocking curve (XRC) analysis. The full width at half maximum (FWHM) values of the (0 0 0 2) and (1 0–1 0) diffractions were 277 and 306 arcsec, respectively. Secondary ion mass spectrometry (SIMS) measurements indicated that the Si and C impurity concentrations were reduced to half of those in the sublimation-grown AlN substrates.

Nomura, Takuya; Okumura, Kenta; Miyake, Hideto; Hiramatsu, Kazumasa; Eryu, Osamu; Yamada, Yoichi

2012-07-01

407

26Al+ p elastic and inelastic scattering reactions and galactic abundances of 26Al  

SciTech Connect

Galactic 26Al is the first radioactive nucleus to be positively identified by -ray astronomy with detection of the 1.809 MeV ray associated with its decay. This nucleus is destroyed in astrophysical environments in the 26Al(p, )27Si and inelastic 26Al+p scattering reactions where properties of 27Si levels determine reaction rates. To investigate these properties, elastic and inelastic 26Al+p scattering reactions were measured between Ec.m. = 0.5 1.5 MeV at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). A candidate for a new resonance in the 26Al(p, )27Si reaction was identified. Upper limits were also set on the strengths of postulated resonances and on the cross section of the inelastic reaction, but there is little effect on current reaction rate calculations.

Pittman, S. T. [University of Tennessee, Knoxville (UTK); Bardayan, Daniel W [ORNL; Chae, K. Y. [University of Tennessee, Knoxville (UTK); Chipps, K. [Colorado School of Mines, Golden; Jones, K. L. [Rutgers University; Kozub, R. L. [Tennessee Technological University; Matei, Catalin [Oak Ridge Associated Universities (ORAU); Matos, M. [Louisiana State University; Moazen, Brian [University of Tennessee, Knoxville (UTK); Nesaraja, Caroline D [ORNL; O'Malley, Patrick [Rutgers University; Pain, Steven D [ORNL; Parker, P.D. [Yale University; Peters, W. A. [Rutgers University; ShrinerJr., J. F. [Tennessee Technological University; Smith, Michael Scott [ORNL

2012-01-01

408

An impedance study of complex Al/Cu-Al2O3 electrode  

NASA Astrophysics Data System (ADS)

Electrochemical impedance spectroscopy (EIS) was used to investigate different Cu deposition regimes on Al surface obtained by internal electrolysis and to characterize properties of fabricated electrodes. EIS experimental data confirmed that Cu deposition by internal electrolysis is realized and the complex electrode system is obtained. The main difficulty in preparation of Al/Cu electrodes is to prevent aluminium oxidation before and during electrochemical deposition of Cu particles. In this work NaCl, CH3COONa, K2SO4, mono- and diammonium citrate electrolytes were examined to determine their suitability for impedance measurements. Al/Cu-Al2O3 electrode composition was approved by equivalent circuit analysis, optical and scanning electron microscope methods. The most optimal Cu deposition mode using internal electrolysis was determined. The obtained results are promising for future electrochemical fabrication of nanostructures directly on Al surfaces by internal electrolysis.

Denisova, J.; Katkevics, J.; Erts, D.; Viksna, A.

2011-06-01

409

Evidence for {open_quotes}loose spins{close_quotes} in epitaxial Al/Fe/Al  

SciTech Connect

Polarization-dependent Fe K-edge x-ray absorption fine structure measurements of an Al/Fe/Al(001) trilayer reveal a small tetragonal distortion of the Fe sites with c=2.863 {Angstrom} (normal to the film plane) and a=2.874 {Angstrom} (in the film plane). This tetragonal distortion is consistent with the formation of Fe{sub 1{minus}x}Al{sub x} alloys in the vicinity of the roughened Fe{endash}Al trilayer interfaces, and agrees with grazing incidence x-ray reflectivity and magnetometry measurements of the trilayer. The deduced alloyed/roughened interfacial regions are the likely source of Fe {open_quotes}loose spins{close_quotes} as recently suggested by Slonczewki{close_quote}s biquadratic coupling model for the epitaxial Fe/Al/Fe system. {copyright} {ital 1997 American Institute of Physics.}

Gutierrez, C.J.; Selestino, R. [Department of Physics, Southwest Texas State University, San Marcos, Texas 78666 (United States); Mayanovic, R.A. [Department of Physics and Astronomy, Southwest Missouri State University, Springfield, Missouri 65804 (United States); Prinz, G.A. [Naval Research Laboratory, Washington, DC 20375 (United States)

1997-04-01

410

Theoretical study of optical properties in deep ultraviolet Al-rich AlGaN/AIN quantum wells  

NASA Astrophysics Data System (ADS)

Optical properties of deep ultraviolet Al-rich AlGaN/AlN quantum wells (QWs) were theoretically investigated by using the multiband effective-mass theory. The theoretical PL transition wavelength is found to agree well with the experimental result. The internal field in AlGaN/AlN QW structures with lower Al contents is much larger than that in QW structures with higher Al contents. The intensity of the spontaneous emission spectra is shown to be improved with increasing Al content because the optical matrix elements are largely enhanced due to the reduced internal field.

Park, S. H.

2009-03-01

411

Growth and characterization of TiAlN\\/CrAlN superlattices prepared by reactive direct current magnetron sputtering  

Microsoft Academic Search

TiAlN and CrAlN coatings were prepared using a reactive direct current magnetron sputtering system from TiAl and CrAl targets. Structural characterization of the coatings using x-ray diffraction (XRD) revealed the B1 NaCl structure of TiAlN and CrAlN coatings with a prominent reflection along the (111) plane. The XPS data confirmed the bonding structures of TiAlN and CrAlN single layer coatings.

Harish C. Barshilia; B. Deepthi; K. S. Rajam; Kanwal Preet Bhatti; Sujeet Chaudhary

2009-01-01

412

Criteria for the formation of protective Al 2O 3 scales on Fe–Al and Fe–Cr–Al alloys  

Microsoft Academic Search

The conditions for the formation of external alumina scales on binary Fe–Al alloys and the nature of the third-element effect due to chromium additions have been investigated by studying the oxidation at 1000°C in 1atm O2 of a binary Fe–10at.% Al alloy (Fe–10Al) and of two ternary Fe–Cr–10at.% Al alloys containing 5 and 10at.% chromium (Fe–5Cr–10Al and Fe–10Cr–10Al, respectively). An

Z. G. Zhang; F. Gesmundo; P. Y. Hou; Y. Niu

2006-01-01

413

Improved electrical properties in AlGaN\\/GaN heterostructures using AlN\\/GaN superlattice as a quasi-AlGaN barrier  

Microsoft Academic Search

The authors report the electrical properties of two-dimensional electron gas (2DEG) in AlGaN\\/GaN heterostructures using AlN\\/GaN superlattices working as a quasi-AlGaN barrier layer. It is found that the electrical properties (2DEG mobility and sheet carrier density) in the quasi-AlGaN\\/GaN heterostructure are greatly improved compared to those in the conventional alloy-AlGaN\\/GaN one at the high Al composition more than 0.35. The

Y. Kawakami; A. Nakajima; X. Q. Shen; G. Piao; M. Shimizu; H. Okumura

2007-01-01

414

Oxidation of Volatile Organic Compounds on Al 2O 3, Pd\\/Al 2O 3, and PdO\\/Al 2O 3Catalysts  

Microsoft Academic Search

Temperature-programmed desorption (TPD) and oxidation (TPO) were used to study the decomposition and oxidation of methanol, ethanol, acetaldehyde, formic acid, and acetic acid on Al2O3, Pd\\/Al2O3, and PdO\\/Al2O3catalysts. The oxidation and decomposition rates were much higher on Pd\\/Al2O3than on Al2O3, even though the volatile organic compounds (VOCs) were adsorbed on the Al2O3support in both cases. The VOCs surface-diffused to Pd

Eric M Cordi; John L Falconer

1996-01-01

415

Al-Li Alloy Developed by Pechiney.  

National Technical Information Service (NTIS)

An up-to-date view of Al-Li development is presented in terms of both properties and production readiness. Successes achieved to date, mostly where damage tolerance and medium strength targets are concerned, will be outlined. Design allowables, properties...

M. Doudeau P. Meyer D. Constant

1989-01-01

416

Legality of al-Qaeda's Jihad.  

National Technical Information Service (NTIS)

Usama Bin Laden, the leader of al-Qaeda, declared war on the United States in a statement issued in August 1996. With the words, 'It is a duty now on every tribe in the Arab Peninsula to fight in the cause of Allah and to cleanse the land from those occup...

S. M. Pelicano

2011-01-01

417

Al-Ghazali on Moral Education  

ERIC Educational Resources Information Center

|Al-Ghazali (1058-1111 CE) is probably the most influential scholar, philosopher, theologian, legal expert, religious reformer and mystic in the history of Islam. Although he wrote extensively about education, and particularly about moral education, this writing is scattered through a number of different works and has received less scholarly…

Alavi, Hamid Reza

2007-01-01

418

Kinematics of Disease Progression in Bulbar ALS  

ERIC Educational Resources Information Center

|The goal of this study was to investigate the deterioration of lip and jaw movements during speech longitudinally in three individuals diagnosed with bulbar amyotrophic lateral sclerosis (ALS). The study was motivated by the need to understand the relationship between physiologic changes in speech movements and clinical measures of speech…

Yunusova, Yana; Green, Jordan R.; Lindstrom, Mary J.; Ball, Laura J.; Pattee, Gary L.; Zinman, Lorne

2010-01-01

419

The Plastic Deformation of TiAl.  

National Technical Information Service (NTIS)

The deformation substructure of TiAl (Llo type ordered lattice) tested in compression, and the factors determining it were investigated. Two types of dislocations take part in the plastic deformation, namely a/2(110) and a/2(011). The latter type will dis...

D. Shechtman M. J. Blackburn H. A. Lipsitt

1973-01-01

420

Microbial Bioreactor Development in the ALS NSCORT  

Microsoft Academic Search

The NASA Specialized Center of Research and Training in Advanced Life Support (the ALS NSCORT), a partnership of Alabama A & M, Howard, and Purdue Universities, was established by NASA in 2002 to develop technologies that will reduce the Equivalent System Mass (ESM) of regenerative processes within future space life-support systems. A key focus area of NSCORT research has been

Cary Mitchell; Dawn Whitaker; M. Katherine Banks; Albert J. Heber; Ronald F. Turco; Loring F. Nies; James E. Alleman; Sybil E. Sharvelle; Congna Li; Megan Heller

2008-01-01

421

Joint SSRTNet/ALS-MES Workshop report  

SciTech Connect

This joint workshop brought together experimentalists and theorists interested in synchrotron radiation and highlighted subjects relevant to molecular environmental science (MES). The strong mutual interest between the participants resulted in joint sessions on the first day, followed by more specialized parallel sessions on the second day. Held in conjunction with the Advanced Light Source (ALS) Users' Association Annual Meeting at the Lawrence Berkeley National Laboratory (Berkeley Lab), the Synchrotron Radiation Research Theory Network (SRRTNet) workshop was co-organized by Michel Van Hove (Berkeley Lab and University of California, Davis) and Andrew Canning (Berkeley Lab), while David Shuh (Berkeley Lab) organized the ALS-MES workshop. SRRTNet is a global network that promotes the interaction of theory and experiment (http://www.cse.clrc.ac.uk/Activity/SRRTnet). The ALS-MES project is constructing Beamline 11.0.2.1-2, a new soft x-ray beamline for MES investigations at photon energies from 75 eV to 2 keV, to provide photons for wet spectroscopy end stations and an upgraded scanning transmission x-ray microscope (STXM). The ALS-MES beamline and end stations will be available for users in the late fall of 2002.

Shuh, David; Van Hove, Michel

2001-11-30

422

Microstructural Change of Al on H Implantation.  

National Technical Information Service (NTIS)

Modifications to the subsurface layer of Al on 25 KeV H2(+) ion implantation to fluences of 4 x 10 to the 17th power - 2 x 10 to the 18th power H(+)/sq cm at room temperature were investigated by transmission electron microscopy (TEM) and elastic recoil d...

K. Kamada A. Sagara H. Kinoshita H. Takahashi

1987-01-01

423

Al Qaeda's Organizational Structure and its Evolution  

Microsoft Academic Search

The inner organizational structure of Al Qaeda within the expanded framework of the “Global Jihad movement” has been a subject of much debate between scholars. As will be elaborated later, the “Global Jihad movement” is composed of several elements that possess radical Islamic ideology and conduct operational activity in different regions in the world under the banner of Jihad. The

Rohan Gunaratna; Aviv Oreg

2010-01-01

424

Ternary Dy-Er-Al magnetic refrigerants  

SciTech Connect

A ternary magnetic refrigerant material comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant.

Gschneidner, Jr., Karl A. (Ames, IA); Takeya, Hiroyuki (Ibaraki, JP)

1995-07-25

425

Ternary Dy-Er-Al magnetic refrigerants  

DOEpatents

A ternary magnetic refrigerant material comprising (Dy{sub 1{minus}x}Er{sub x})Al{sub 2} for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant. 29 figs.

Gschneidner, K.A. Jr.; Takeya, Hiroyuki

1995-07-25

426

SPI measurements of Galactic 26Al  

NASA Astrophysics Data System (ADS)

The precision measurement of the 1809 keV gamma-ray line from Galactic 26Al is one of the goals of the SPI spectrometer on INTEGRAL with its Ge detector camera. We aim for determination of the detailed shape of this gamma-ray line, and its variation for different source regions along the plane of the Galaxy. Data from the first part of the core program observations of the first mission year have been inspected. A clear detection of the 26Al line at =~ 5-7 sigma significance demonstrates that SPI will deepen 26Al studies. The line intensity is consistent with expectations from previous experiments, and the line appears narrower than the 5.4 keV FWHM reported by GRIS, more consistent with RHESSI's recent value. Only preliminary statements can be made at this time, however, due to the multi-component background underlying the signal at =~ 40 times higher intensity than the signal from Galactic 26Al.

Diehl, R.; Knödlseder, J.; Lichti, G. G.; Kretschmer, K.; Schanne, S.; Schönfelder, V.; Strong, A. W.; von Kienlin, A.; Weidenspointner, G.; Winkler, C.; Wunderer, C.

2003-11-01

427

Ibn al-Haytham and psychophysics.  

PubMed

Persian scholar Ibn al-Haytham ('Alhazen') has rightly been credited with many advances in optics and vision science, but recent spurious claims that he is the 'founder of psychophysics' rest upon unsupported assertions, a conflation of psychophysics with the wider discipline of psychology, and semantic arguments over what it is to 'found' a school of thought. PMID:18546671

Aaen-Stockdale, Craig

2008-01-01

428

Primary (AL) Amyloidosis in Plasma Cell Disorders  

Microsoft Academic Search

Primary (AL) amyloidosis is the most common form of systemic amyloidosis. The morbidity arises from extra- cellular deposition of immunoglobulin light chain (LC) fibrils in major organs, such as the kidneys, heart, and bowel. Organ dysfunction contributes to a high mortal- ity and poor prognosis, with a median survival time of 1-2 years from diagnosis. Here, we present a 46-year-

Antonia M. S. Müller; Annette Geibel; Hartmut P. H. Neumann; Alexander Kühnemund; Annette Schmitt-Gräff; Joachim Böhm; Monika Engelhardt

429

Building the Base: Al Qaeda's Focoist Strategy  

Microsoft Academic Search

Al Qaeda has developed a coherent strategy for insurgent violence that has much in common with the focoism advocated by Che Guevara in the 1960s. In their strategic writing, explored here, key Islamist strategists stress the role of violence in creating revolution, and describe the export of committed fighters to focoist enclaves at the margins of enemy control. In contrast

Kenneth Payne

2011-01-01

430

Mechanical properties of Al metal foams  

Microsoft Academic Search

Pure Al foams, produced by a melt foaming method, were characterized by optical and electron microscopy and found to have a uniform microstructure. Their mechanical properties under compression were evaluated using a microtest apparatus in the Scanning Electron Microscopy (SEM) vacuum chamber while observing in situ the crack initiation. Their main mechanical properties, that is, the Young's modulus and the

D. P Papadopoulos; I. Ch Konstantinidis; N Papanastasiou; S Skolianos; H Lefakis; D. N Tsipas

2004-01-01

431

Lowest Ionization Potentials of Al2.  

National Technical Information Service (NTIS)

Potential curves for the lowest two electronic states (X 2 sigma g + and A 2 pi u) of Al2(+) were computed using complete active space SCF/multireference CI wave functions and large Gaussian basis sets. The lowest observable vertical ionization potential ...

C. W. Bauschlicher L. A. Barnes P. R. Taylor

1988-01-01

432

Kinematics of Disease Progression in Bulbar ALS  

PubMed Central

The goal of this study was to investigate the deterioration of lip and jaw movements during speech longitudinally in three individuals diagnosed with bulbar Amyotrophic Lateral Sclerosis (ALS). The study was motivated by the need to understand the relationship between physiologic changes in speech movements and clinical measures of speech performance such as speaking rate and speech intelligibility. Movements of the lip and jaw were quantified with respect to their size (i.e., path distance measure), speed, and duration. The data revealed several changes in lip and jaw movement that coincided with ALS progression. In two out of three speakers, the changes in measures of path distance and speed anticipated the drop in speech intelligibility by approximately 3 months. With disease progression, increases in movement duration coincided with declines in speech intelligibility. Overall, the movement measures appeared to be sensitive to disease progression in ALS. Learning outcomes By the end of the manuscript, the reader should be able to: (1) describe the changes that occur in articulatory movements of the jaw and lower lip in ALS; (2) understand the relationship between physiologic measures of movement and speech intelligibility and speaking rate; (3) identify critical points in the disease progression and understand which quantitative measures reveal the state of the bulbar system at these time points.

Yunusova, Yana; Green, Jordan; Lindstrom, Mary; Ball, Laura; Pattee, Gary; Zinman, Lorne

2009-01-01

433

GaAlAsSb APD Optimization.  

National Technical Information Service (NTIS)

It has been demonstrated that avalanche gain can be obtained in GaAlSb avalanche photodiodes which exhibit ionization coefficient enhancement. These devices exhibit gain at relatively high impurity background density of 8-9 x 10 to the 15th power/cu cm. T...

R. Chin

1984-01-01

434

Synopsis of "Reply to Levitas et al."  

ERIC Educational Resources Information Center

|This synopsis of a reply by Wolf Wolfensberger to a critique by Levitas et al. (EC 609 743) notes extensive documentation supporting Wolfensberger's assertion that prescription psychoactive drugs are health destroying and life destroying. Issues of truth and of epistemology are identified as they apply to the treatment of these socially devalued…

O'Brien, John

1994-01-01

435

The Female Jihad: Al Qaeda's Women  

Microsoft Academic Search

When women carry out a suicide attack they undermine the idea of who and what a terrorist is. What is generally not realized is the extent to which women are involved in terrorism. The purpose of this article is to explore and to analyze the multifaceted roles of the women in the movement of Al Qaeda. The argument is that

Katharina Von Knop

2007-01-01

436

THE CREEP BEHAVIOUR OF MAGNOX AL80  

Microsoft Academic Search

An empirical secondary creep law for Magnox AL80 is deduced from ; selected data and compared with a creep law due to Ward. An activation energy ; for creep is obtained. All available experimental results are used to suggest ; that extrapolation of the selected points by the laws considered leads to ; optimistic results at higher stress levels. Proof''

L. R. T. Gardner; W. N. Miller

1962-01-01

437

Al Qaeda Refining a Failing Strategy.  

National Technical Information Service (NTIS)

Al Qaeda's inability to translate its post-9/11 approval in the Muslim world into a mass movement jihad against the West is prompting a search for new ways to regenerate lost momentum, but the group's inherent weaknesses are likely to prevent progress and...

M. J. Hart

2008-01-01

438

Mechanochemical synthesis and crystal structure of alpha'-AlD3 and alpha-AlD3.  

PubMed

AlD3 AlD3 was synthesized by ball milling of 3LiAlD4 + AlCl3. Planetary ball milling at room temperature resulted in a mixture of AlD3 (alpha and alpha') and Al in addition to LiCl, whereas cryomilling at 77 K resulted in only AlD3 and LiCl. The AlD3 obtained was a mixture of about 2/3alpha and 1/3alpha'. Alpha' was determined by powder neutron diffraction to take the beta-AlF3 structure with space group Cmcm and a = 6.470(3), b = 11.117(5), and c = 6.562(2) A. It is built up of corner-sharing AlD6 octahedra in an open structure with hexagonal holes of radius 3.9 A. Alpha' slowly decomposes during storage at 40 degrees C. Alpha-AlD3 is also described by a corner-sharing AlD6 network but in a more dense ReO3-type arrangement. Both AlD3 modifications have slightly shorter Al-D distances compared to Na3AlD6, Na2LiAlD6, and K2NaAlH6. PMID:17181228

Brinks, Hendrik W; Istad-Lem, Andreas; Hauback, Bjørn C

2006-12-28

439

Hydrogen Solubility in Al-bearing Perovskite  

NASA Astrophysics Data System (ADS)

It is generally accepted that silicate perovskite is the dominant mineral in the Earth's lower mantle. Previous studies have been completed to determine the physical and chemical characteristics of the pure end-member MgSiO3. Recent studies have shown that the addition of Al to MgSiO3 can have a significant effect on the material properties of the mineral, such as compressibility, and defect structure, as well as a great potential to dissolve water. We have synthesized Al-bearing perovskite samples under hydrous conditions in a multi-anvil apparatus at pressures ranging from 23-26 GPa and 1800oC. The starting materials consisted of brucite and silica powders mixed together and finely ground in a 1:1 molar ratio, with subsequent addition of Al2O3 powder at 2wt% intervals from 0%-6%. The mixed powders were tightly packed in Au capsules, housed in BN sleeves, and loaded into standard 8/3 multi-anvil assemblies. The experiments were brought to the appropriate pressure conditions for solubility of the different Al2O3 contents. The resulting perovskite crystals range in size from <20 microns to >100 microns in size. Their major element chemistry has been characterized by EPMA, and the H content of some samples has been measured by secondary ion mass spectrometry using a 6f Cameca ion microprobe and is substantial (>1200ppm in some samples). In this study, we correlate H content in the perovskites with Al concentration, and discussion follows on what effects this may have on potential substitution mechanisms, and correlated formation of oxygen vacancies, as well as water storage in the mantle, oxygen diffusion, and the potential of an oxygen ionic diffusion contribution to electrical conductivity in the mantle.

Watson, H. C.; Krawczynski, M. J.; Fei, Y.

2005-12-01

440

Influence of Schottky drain contacts on the strained AlGaN barrier layer of AlGaN/AlN/GaN heterostructure field-effect transistors  

NASA Astrophysics Data System (ADS)

Rectangular Schottky drain AlGaN/AlN/GaN heterostructure field-effect transistors (HFETs) with different gate contact areas and conventional AlGaN/AlN/GaN HFETs as control were both fabricated with same size. It was found there is a significant difference between Schottky drain AlGaN/AlN/GaN HFETs and the control group both in drain series resistance and in two-dimensional electron gas (2DEG) electron mobility in the gate—drain channel. We attribute this to the different influence of Ohmic drain contacts and Schottky drain contacts on the strained AlGaN barrier layer. For conventional AlGaN/AlN/GaN HFETs, annealing drain Ohmic contacts gives rise to a strain variation in the AlGaN barrier layer between the gate contacts and the drain contacts, and results in strong polarization Coulomb field scattering in this region. In Schottky drain AlGaN/AlN/GaN HFETs, the strain in the AlGaN barrier layer is distributed more regularly.

Cao, Zhi-Fang; Lin, Zhao-Jun; Lü, Yuan-Jie; Luan, Chong-Biao; Wang, Zhan-Guo

2013-04-01

441

The Heats of Formation of AlClF2 and AlCl2F from Subliming AlF3 in the Presence of AlCl3 Vapor.  

National Technical Information Service (NTIS)

The volatility of AlF3, which was measured between 1196 and 1256K by an entrainment method, was enhanced by the presence of AlCl3 vapor. When the AlCl3 was generated by subliming at 373 or 394K, the amount of sublimed AlF3 was observed to be from 1.7 to 7...

R. F. Krause T. B. Douglas

1968-01-01

442

Thermoelectric Powers of Cells With NaF-AlF3-Al2O3 Melts  

NASA Astrophysics Data System (ADS)

A thermodynamic description of the Peltier heat at the aluminum and the oxygen electrode in the system NaF-AlF3-Al2O3 is given. The thermoelectric power in melts with molar ratios n NaF/n AlF3 from 3.0 to 1.0, saturated with alumina are measured. Seebeck coefficients for molten fluoride electrolytes saturated with alumina, electrolytes that are relevant for aluminum electrowinning electrolysis cells, are reported. The results allow determinations of Peltier heats of aluminum, oxygen and carbon electrodes in NaF-AlF3 electrolytes saturated with alumina. For molar ratios of n NaF/n AlF3 between 2.6 and 1.2, there is a Peltier heating of the aluminum cathode. This heating is in the same order of magnitude as the electrolyte Joule heat, when the current density is 0.7 A cm-2. For molar ratio n NaF/n AlF3 equal to 1.0 the Peltier effect at the aluminum electrode approaches zero. From theoretical considerations we expect a drop also for molar ratio 3.0. For the anode we report a Peltier cooling that is larger than the heat produced by the anodic overvoltage, in melts with NaF/AlF3 molar ratio between 2.6 and 1.2 saturated with alumina.

Flem, Belinda E.; Xu, Qian; Kjelstrup, Signe; Sterten, Åsmund

2001-07-01

443

Segregation at Coherent Interphase Boundaries: The Case of Mg at Al/Al_3Sc  

NASA Astrophysics Data System (ADS)

Recent advances in experimental methods have made possible the measurement of compositional variations at internal interfaces with near atomic-scale resolution. The combined application of such characterization techniques with first-principles computations provides the basis for greatly expanded insight into the microscopic factors governing interfacial segregation in multicomponent systems. This talk will discuss the application of such a combined experimental/computational approach in a study of Mg in two-phase Al-Sc-Mg alloys. Three-dimensional atom-probe and high-resolution electron microscopy measurements show a pronounced segregation of Mg solute atoms at the coherent interface between fcc-based Al and Al_3Sc phases, correlated with a Mg-induced decrease in the degree of faceting of Al_3Sc precipitates. The origin of these observed effects is investigated through the application of first-principles thermodynamic calculations. A significant driving force for the equilibrium segregation of Mg to coherent Al/Al_3Sc interfaces is derived from these calculations, which is found to be primarily ``chemical" in origin. The extension of this work to related Al-alloy systems will be discussed.

Asta, M.; Marquis, E. A.; Seidman, D. N.; Woodward, C.; Ozolins, V.

2004-03-01

444

An Epidemiological Study of Cutaneous Leishmaniasis in Al-Jabal Al-Gharbi, Libya  

PubMed Central

Cutaneous leishmaniasis (CL) is an endemic parasitic infection in the Mediterranean region, including Libya and its Al-jabal Al-gharbi province. We aimed at studying the occupational relevance as well as other epidemiological aspects of CL. We investigated 140 CL cases who attended at Gharyan outpatient polyclinic during a period of 6 months in 2009. CL infection was clinically diagnosed and confirmed by demonstration of Leishmania parasites on smears from lesions. Our findings showed that males were more affected than females (P=0.04), and people above 10-years were more affected than younger ones (P=0.0001). A significant percent of CL cases belonged to Al-Kawasem subprovince (P=0.0001). Farm-related activities were the most frequent occupations among CL cases (P=0.04). In addition to farm workers, housewives and students are at risk groups since they are engaged at farm activities. Moreover, those who have occupations that require staying outdoors for a part of night, e.g., policemen, are also at risk. Compared to children, adult CL patients had multiple lesions (P=0.001) that were more prevalent in their upper and lower extremities than the face (P=0.0001). We conclude that CL is a major health problem in Al-jabal Al-gharbi province of Libya. The presence of rodents and sandflies makes it a suitable environment for Leishmania to spread in an endemic epidemiological pattern. Being engaged in farming activities or outdoor occupations increases the risk of infection. Various clinical patterns of CL suggest the presence of more than 1 species of Leishmania at Al-jabal Al-gharbi province. We propose that the 2 species responsible for CL in this area are L. major and L. tropica. Further investigations to identify the leishmanial species responsible for CL at Al-jabal Al-gharbi together with adoption of preventive and control programs are needed.

Abdellatif, Manal Z. M.; El-Mabrouk, Khamis

2013-01-01

445

Phase equilibria in the ternary Al-Sc-Mn system  

NASA Astrophysics Data System (ADS)

Optical microscopy, electron microprobe analysis, and electrical resistivity measurements are used to study Al-Sc-Mn alloys containing up to 3 at % Sc and to 2.5 at % Mn. The boundaries of the Al-based solid solution are determined at 640, 600, and 400°C, and the isothermal section of the Al-rich portion of the Al-Sc-Mn system at 640°C is constructed. The Al-based solid solution is found to be in equilibrium with the ScAl3 and MnAl6 phases.

Rokhlin, L. L.; Bochvar, N. R.; Lysova, E. V.; Leonova, N. P.; Korol'Kova, I. G.

2008-02-01

446

Quantitative x-ray photoelectron spectroscopy study of Al/AlOx bilayers  

NASA Astrophysics Data System (ADS)

An x-ray photoelectron spectroscopy (XPS) analysis of Nb/Al wedge bilayers, oxidized by both plasma and natural oxidation, is reported. The main goal is to show that the oxidation state--i.e., O:(oxidize)Al ratio--, structure and thickness of the surface oxide layer, as well as the thickness of the metallic Al leftover, as functions of the oxidation procedure, can be quantitatively evaluated from the XPS spectra. This is relevant to the detailed characterization of the insulating barriers in (magnetic) tunnel junctions.

Batlle, Xavier; Hattink, Bart Jan; Labarta, Amilcar; Akerman, Johan J.; Escudero, Roberto; Schuller, Ivan K.

2002-06-01

447

Interdiffusion in Diffusion Couples: U-Mo v. Al and Al-Si  

Microsoft Academic Search

Interdiffusion and microstructural development in the U-Mo-Al system was examined using solid-tosolid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, annealed at 600°C for 24 hours. The influence of Si alloying addition (up to 5 wt.%) in Al on the interdiffusion microstructural development was also examined using solid-to-solid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs.

Jr. D. D. Keiser; E. Perez; B. Yao; Y. H. Sohn

2009-01-01

448

Phase equilibria in Al-rich Al-Sc-Cr alloys  

NASA Astrophysics Data System (ADS)

Phase equilibria in aluminum alloys containing up to 1.2 wt % Sc and 1.0 wt % Cr are studied by optical microscopy and differential thermal and electron microprobe analyses. Two vertical sections and the projection of liquidus surface have been constructed. The four-phase nonvariant equilibrium at a temperature of 656.5 ± 1°C is found to have a transition character. The Al-based solid solution is found to be in equilibrium only with the Al3Sc and Al7Cr binary phases.

Rokhlin, L. L.; Dobatkina, T. V.; Bochvar, N. R.

2007-02-01

449

On the crack growth resistance and strength of the B2 iron aluminides Fe-40Al, Fe-45Al, and Fe-10Ni-40Al (at. %)  

SciTech Connect

The crack growth resistance and yield strength of the B2 iron aluminides Fe-40Al, Fe-45Al, are Fe-10Ni-40Al (at. %) have been investigated at room temperature laboratory air. After fast cooling from 1273 K, Fe-45Al and Fe-10Ni-40Al are much stronger than Fe-40Al, and exhibit considerably lower crack growth resistance. The crack growth resistance decreases with decreasing crack propagation velocity. Low crack propagation velocities favor intergranular fracture, whereas high velocities can lead to significant contributions from transgranular fracture. Boron additions to Fe-40Al and Fe-10Ni-40Al improve the crack growth resistance, reduce its dependence on the crack propagation velocity, and cause the path to be predominantly transgranular. In a plot of fracture toughness versus yield strength, the properties of the iron aluminides are similar to those of typical aluminum alloys.

Schneibel, J.H.; Maziasz, P.J.

1994-09-01

450

Improved electrical properties in AlGaN/GaN heterostructures using AlN/GaN superlattice as a quasi-AlGaN barrier  

NASA Astrophysics Data System (ADS)

The authors report the electrical properties of two-dimensional electron gas (2DEG) in AlGaN/GaN heterostructures using AlN/GaN superlattices working as a quasi-AlGaN barrier layer. It is found that the electrical properties (2DEG mobility and sheet carrier density) in the quasi-AlGaN/GaN heterostructure are greatly improved compared to those in the conventional alloy-AlGaN/GaN one at the high Al composition more than 0.35. The improved 2DEG properties result in the reduction of the sheet resistance to as low as 172 ?/squarelg, which is extremely important for the high power and high frequency device application. Theoretical calculations clearly indicate that the quasi-AlGaN barrier plays an important role in enhancing the confinement of the carrier at the quasi-AlGaN/GaN interface.

Kawakami, Y.; Nakajima, A.; Shen, X. Q.; Piao, G.; Shimizu, M.; Okumura, H.

2007-06-01

451

The study of preparation of AlN powder  

Microsoft Academic Search

Highly purified fine AlN powder was synthesized with low oxygen content. The optimal raw materials were Al2O3 dehydrated from Al(OH)3, carbon black, and AlN seed crystal, and their weight proportion was 1:0.5:0.01, respectively. Appropriate addition of AlN seed crystals might make the product finer. The order of the reaction was zero whose rate constants were 0.23 mol\\/L-s at 1400°C and

D. F. Qian; Z. D. Xiong

1991-01-01

452

Magnetomechanical hysteresis damping in FeAl alloys  

Microsoft Academic Search

The magnetomechanical hysteresis damping of Fe-Al alloys has been investigated using a computer-controlled automatic inverted torsion pendulum. It has been shown that Al content and heat treatment have a significant effect on the magnetomechanical hysteresis damping of the alloys. The Fe-10.5 (at.%)Al alloy has an optimal damping capacity after it was air-cooled from 900°C and the Fe-Al alloys with 29(at.)%Al

Z. C. Zhou; Z. C. Shen; Z. Jiang; F. S. Han

2005-01-01

453

Internal friction of ?-TiAl alloys at high temperature  

Microsoft Academic Search

Intermetallic ?-TiAl based alloys of engineering interest with respect to high temperature applications are two-phase alloys consisting of ?-TiAl (ordered face-centered tetragonal structure) and ?2-Ti3Al (ordered hexagonal structure). For this investigation a ?-TiAl based alloy with a composition of Ti-46.4 at%Al-4 at% (Cr, Nb, Ta, B) was studied utilizing a low frequency subresonance apparatus at frequencies between 0.01 and 10

M Weller; A Chatterjee; G Haneczok; H Clemens

2000-01-01

454

Synthesis and oxidation resistance of TiAlSiN and multilayer TiAlSiN\\/CrAlN coating  

Microsoft Academic Search

Oxidation resistant is one main factor to investigate for protective coatings of cutting tool application. In addition the formation of multilayer structure can be an alternative in improving the oxidation resistance. The monolayer TiAlSiN and multilayer TiAlSiN\\/CrAlN coating was deposited by cathodic arc ion-plating (AIP) method and oxidation resistance was studied in the range of 800 to 1000 °C. TiAlSiN with

N. Fukumoto; H. Ezura; T. Suzuki

2009-01-01

455

The inhibition of the corrosion of Al, Al6061 and AlCu in chloride free aqueous media: I. Passivation in acid solutions  

Microsoft Academic Search

The electrochemical behaviour of Al, Al-6061 and Al-Cu was investigated in solutions of different pH. The inhibition of the corrosion processes occurring at the electrode\\/electrolyte interface in solutions of borate buffers (pH 2) was studied. Molybdates and dichromates show pronounced inhibition action which was investigated and discussed. X-ray photoelectron spectroscopy (XPS) experiments have shown that Al-Cu alloys have remarkable Cu

W. A. Badawy; F. M. Al-Kharafi

1997-01-01

456

Reaction between amorphous Si and crystalline Al in Al\\/Si and Si\\/Al bilayers: microstructural and thermodynamic analysis of layer exchange  

Microsoft Academic Search

Aluminium-induced crystallization of amorphous silicon (a-Si) in Al\\/Si and Si\\/Al bilayers was studied upon annealing at 250 °C by X-ray diffraction and Auger electron spectroscopy. The Al\\/a-Si bilayers and a-Si\\/Al bilayers were prepared by sputter deposition on single-crystal silicon wafers with a silicon-oxide film on top. During the isothermal annealing a layer-exchange process occurred in both types of bilayers. A

D. He; J. Y. Wang; E. J. Mittemeijer

2005-01-01

457

Reaction between amorphous Si and crystalline Al in Al\\/Si and Si\\/Al bilayers: microstructural and thermodynamic analysis of layer exchange  

Microsoft Academic Search

Aluminium-induced crystallization of amorphous silicon (a-Si) in Al\\/Si and Si\\/Al bilayers was studied upon annealing at 250 °C by X-ray diffraction and Auger electron spectroscopy. The Al\\/a-Si bilayers and a-Si\\/Al bilayers were prepared by sputter deposition on single-crystal silicon wafers with a silicon-oxide film on top. During the isothermal annealing a layer-exchange process occurred in both types of bilayers. A continuous

D. He; J. Y. Wang; E. J. Mittemeijer

2005-01-01

458

The effect of hot-rolling on chill-cast Al, Al2 wt % Ni and Al4 wt % Ni alloys  

Microsoft Academic Search

The effect of hot-rolling on the mechanical properties and microstructure of directionallysolidified hypoeutectic Al-Al3Ni alloys has been studied. Chill-cast hypoeutectic alloys were produced by casting into pre-heated mild-steel moulds placed on copper chills. The chill-cast Al-2 wt% Ni and Al-4 wt% Ni hypoeutectic alloys can be hot-rolled at 500‡ C to reductions of greater than 95%. Deformation is achieved by

F. S. J. Jabczynski; B. Cantor

1982-01-01

459

Nuclear Quadrupole Coupling and Crystal-Field Effects in the Cubic Intermetallic Compounds ErAl3, TmAl3, and YbAl3  

Microsoft Academic Search

The presence of a large nuclear quadrupole coupling of the Al nucleus, as measured with NMR, in the cubic rare-earth aluminum intermetallic compounds beta-ErAl3, TmAl3, and YbAl3 indicates that the net charges at the rare-earth and aluminum sites differ by as much as 3 to 4 unit charges. Data on the magnetic susceptibility and this result have been used to

H. W. de Wijn; A. M. van Diepen; K. H. Buschow

1970-01-01

460

Role of Si on the Al behavior in the reaction layer of Al/UMo diffusion couples  

SciTech Connect

The basic experimental features characterizing the Al-Si/U-Mo interface are identified in this atomistic modeling effort, such as the formation of interfacial compounds, Si depletion in the Al matrix near the interface, reduced Al diffusion in the UMo solid solution, and the interaction between Mo and Si which inhibits Al and Si diffusion to the UMo bulk.

Garces, Jorge E.; Bozzolo, Guillermo; Hofman, Gerard; Rest, Jeffrey [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 Bariloche (Argentina); Ohio Aerospace Institute, Cleveland, Ohio 44142 and NASA Glenn Research Center, Cleveland, Ohio 44135 (United States); Argonne National Laboratory, 9700 South Cass Ave., Argonne, Illinois 60439 (United States)

2007-02-12

461

Role of Si on the Al behavior in the reaction layer of Al/UMo diffusion couples  

NASA Astrophysics Data System (ADS)

The basic experimental features characterizing the Al-Si/U-Mo interface are identified in this atomistic modeling effort, such as the formation of interfacial compounds, Si depletion in the Al matrix near the interface, reduced Al diffusion in the UMo solid solution, and the interaction between Mo and Si which inhibits Al and Si diffusion to the UMo bulk.

Garcés, Jorge E.; Bozzolo, Guillermo; Hofman, Gerard; Rest, Jeffrey

2007-02-01

462

Microstructural evolution and hardness of TiAl3 and TiAl2 phases on Ti-45Al-2Nb-2Mn-1B by plasma pack aluminizing  

NASA Astrophysics Data System (ADS)

Plasma pack aluminizing of Ti-45Al-2Nb-2Mn-1B forms TiAl3 and TiAl2 phases.The TiAl3 and TiAl2 phases contain Cu, Nb and Mn.TiAl3 and TiAl2 appear as blocky, needle type and round particles in a matrix of aluminum alloy.Microhardness of TiAl3 and TiAl2 phases is higher than the substrate.

Rastkar, Ahmad Reza; Parseh, Pejman; Darvishnia, Naser; Hadavi, Seyed Mohammad Mehdi

2013-07-01

463

Phase composition of Al-Rich Al-Sc-Cr-Zr alloys at 640, 600, and 500°C  

NASA Astrophysics Data System (ADS)

Metallographic and electron microprobe analyses and hardness and electrical resistivity measurements are used to study Al-rich Al-Sc-Cr-Zr alloys annealed and quenched from 640, 600, and 500°C. The boundaries of Al-based solid solution are determined; the Al-based solid solution is found to be in equilibrium with the CrAl7 compound and ScAl3- and ZrAl3-based phases, in which zirconium and scandium are dissolved, respectively. Sections of isothermal tetrahedra at 640, 600, and 500°C are constructed.

Rokhlin, L. L.; Bochvar, N. R.; Leonova, N. P.; Korol'Kova, I. G.

2011-05-01

464

Self-Separation of Sublimation-Grown AlN with AlSiN Buffer Layer  

NASA Astrophysics Data System (ADS)

AlN was grown by a sublimation method on 6H-SiC. We found the grown AlN layer is easily separated from the substrate when Si powder is added to the AlN source powder. The formation of AlSiN layer with the Si content of 15% at the AlN/6H-SiC interface was confirmed by energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). This AlSiN layer causes the separation of AlN.

Nishino, Katsushi; Nakauchi, Jun; Hayashi, Kotaro; Tsukihara, Masashi

2013-08-01

465

Accurate interatomic potentials for Ni, Al and Ni/sub 3/Al  

SciTech Connect

To obtain meaningful results from atomistic simulations of materials, the interatomic potentials must be capable of reproducing the thermodynamic properties of the system of interest. Pairwise potentials have known deficiencies that make them unsuitable for quantitative investigations of defective regions such as crack tips and free surfaces. Daw and Baskes (Phys. Rev. B 29, 6443 (1984)) have shown that including a local ''volume'' term for each atom gives the necessary many-body character without the severe computational dependence of explicit n-body potential terms. Using a similar approach, we have fit an interatomic potential to the Ni/sub 3/Al alloy system. This potential can treat diatomic Ni/sub 2/, diatomic Al/sub 2/, fcc Ni, fcc Al and L1/sub 2/ Ni/sub 3/Al on an equal footing. Details of the fitting procedure are presented, along with the calculation of some properties not included in the fit.

Voter, A.F.; Chen, Shao Ping

1986-01-01

466

Rapid Solidification Processing of Al3Ti and Al3Ti Plus Copper.  

National Technical Information Service (NTIS)

The development of advanced airframes and propulsion systems has generated significant research and development activity in the area of light weight, high temperature intermetallic alloys, e.g., alpha-two and gamma titanium aluminides. However, Al3Ti, an ...

H. Tyndall J. Benci J. Zanter W. F. Frazier

1990-01-01

467

Al Speciation in Silicate Melts: AlV a new Network Former?  

NASA Astrophysics Data System (ADS)

The first human glasses were made 3500 BC. It was essentially sodo-lime silicate glass. To improve the chemical resistance, the thermal properties and increase the viscosity it is interesting to add aluminum in these silicates. But what is the speciation of the aluminum and how it varies according to the chemical composition and to the temperature? The aluminum appears essentially in four or five fold coordination in glasses and melts melted. The proportion of [5]Al varies according to the alkaline or to the earth-alkaline content and to the temperature. We shall present in a first part the influence of the network-modifier on the proportion of [5]Al and then we shall present some new results of absorption of high-temperature using NMR and XANES spectroscopy at the Al K-edge. Finally, from glass transition temperature measurements we propose to explain that [5]Al can be a new network former.

Neuville, D. R.; Florian, P.; de Ligny, D.; Montouillout, V.; Massiot, D.

2009-05-01

468

Fabrication of Fe-Al nanoparticles by selective oxidation of Fe-Al thin films  

NASA Astrophysics Data System (ADS)

The possibility of a new technique for fabricating nanoparticles from thin films using selective oxidation in an atmosphere mixture of water vapor and hydrogen was investigated. Fe-5wt.%Al films were RF-sputtered and annealed in the atmosphere mixture at 900°C for up to 200 min, in order to oxidize aluminum selectively. Thermodynamics simulation showed that temperatures exceeding 800°C are necessary to prevent iron from being oxidized, as confirmed by the depth profile of XPS. As the annealing time increased, the morphology of the 200-nm Fe-Al films changed from the continuous to the discontinuous type; thus, particulate Fe-Al films formed after 100 min. The particulate 10- to 100-nm Fe-Al films showed super-paramagnetic behavior after the oxidation. Thus, a new technique for fabricating nanoparticles was successfully introduced using selective oxidation.

Jang, Pyungwoo; Shin, Seungchan; Jung, Chip-Sup; Kim, Kwang-Ho; Seomoon, Kyu

2013-04-01

469

Nonstatistical fluctuations for deep inelastic processes in {sup 27}Al+{sup 27}Al collisions  

SciTech Connect

The excitation functions (EFs) for different fragments produced in the {sup 27}Al+{sup 27}Al dissipative collisions have been measured in steps of 250 keV in the incident energy range 122-132 MeV. Deep inelastic processes have been selected by integrating events on a total kinetic energy loss window of 12 MeV between 20 and 32 MeV. Large fluctuations are observed in all the studied EFs. Large-channel cross-correlation coefficients confirm the nonstatistical origin of these fluctuations. The energy autocorrelation function (EAF) shows damped oscillation structure as expected when a dinuclear system with a lifetime [{tau}=(5.1{+-}2.1){center_dot}10{sup -21}s], similar with its revolution period (T=4.9{center_dot}10{sup -21}sec), is formed. From the periodicity of the EAF oscillations, information on the deformation of the {sup 27}Al+{sup 27}Al dinucleus is inferred.

Berceanu, I.; Duma, M.; Moisa, D.; Petrovici, M.; Pop, A.; Simion, V. [National Institute of Physics and Nuclear Engineering, P.O. Box MG-6, H-76900 Bucharest (Romania); Zoppo, A. Del [Istituto Nazionale di Fisica Nucleare, Laboratorio Nazionale del Sud, v. S. Sofia 44, I-95100, Catania (Italy); D'Erasmo, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, v. Amendola 173, I-70126 Bari (Italy); Dipartimento di Fisica, Universita di Bari, V. Amendola 173, I-70126, Bari (Italy); Imme, G.; Lanzano, G.; Pagano, A. [Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica, I-95129 Catania (Italy); Pantaleo, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, v. Amendola 173, I-70126 Bari (Italy); Raciti, G. [Istituto Nazionale di Fisica Nucleare, Laboratorio Nazionale del Sud, v. S. Sofia 44, I-95100, Catania (Italy); Dipartimento di Fisica, Universita di Catania, I-95129 Catania (Italy)

2006-08-15

470

Ohmic contact to n-AlGaN through bonding state transition at TiAl interface  

NASA Astrophysics Data System (ADS)

We report the optimized ohmic contact to high Al content n-AlGaN through modification of the interfacial bonding state of TiAl alloy. First-principles calculations demonstrate that the change of interfacial bonding state (N rich to Al rich) at the TiAl/n-AlGaN interface is crucial for the formation of low barrier contact. The significant electron-transfer and strong orbital hybridization between the Ti atoms and the nearest Al atoms plays a key role in lowering the contact barrier. After treatment of the TiAl/n-AlGaN sample via rapid thermal annealing, perfectly linear I-V characteristic is achieved and the elemental profile by Auger electron spectroscopy confirms the N-rich-to-Al-rich local state transition in the interfacial layers.

Zhang, Binbin; Lin, Wei; Li, Shuping; Zheng, Yu; Yang, Xu; Cai, Duanjun; Kang, Junyong

2012-06-01

471

Early stage of Al3Zr precipitation in a rapidly solidified Al-Cr-Zr alloy  

Microsoft Academic Search

Early stages of A13Zr precipitation have been studied in detail in the ternary Al-2.4 at.% Cr-1.1 at.% Zr alloy. A supersaturated solid solution of Zr in the asrapidly solidified state decomposes during subsequent heat treatment at 400°C. This decomposition leads to a homogeneous precipitation of very small Al3Zr (LI2) particles in the grain interior, but this homogeneous precipitation is not

H. Octor; S. Naka

1989-01-01

472

LP MOVPE growth and characterization of high Al content Al x Ga 1? x N epilayers  

Microsoft Academic Search

High quality AlxGa1?xN layers have been grown on sapphire (0001) by low pressure metalorganic vapour phase epitaxy (LP MOVPE) at 1180°C. The aluminum content covers a wide composition range varying from 0 to 65%. In order to ameliore the quality of these epilayers especially for high aluminum content (XsAl >0.35), growth conditions are carefully optimized. The growth rate of AlGaN

C. Touzi; F. Omnès; B. El Jani; P. Gibart

2005-01-01

473

Experimental study of through-depth residual stress in explosive welded Al–Cu–Al multilayer  

Microsoft Academic Search

Explosive welded multi-layers sheet metals are widely used in recent years. Evaluation of residual stresses of this new merging material is necessary for better understanding of its mechanical behavior. In this paper, incremental hole-drilling (IHD) is used to measure through-depth non-uniform residual stress gradient in explosive welded Al–Cu–Al multilayers. At first, the multilayer sheets at two different initial thicknesses were

M. Sedighi; M. Honarpisheh

474

Experimental studies on the ignition of single Ni\\/Al, Fe\\/Al, and Ti particles  

Microsoft Academic Search

The work presented here focuses on the ignition of single Ni- and Fe-coated Al particles in pure CO2 and Ar atmospheres and Ti particles in O2\\/N2 and O2\\/Ar environments. The importance of studying Ni- and Fe-coated Al particles is related to their potential use in propulsion and materials synthesis applications. Meanwhile, Ti combustion may be utilized to eliminate hazardous chemical

Timothy Al Andrzejak

2007-01-01

475

Corrosion Behavior of Twin-Roll Cast Al-Mg and Al-Mg-Si Alloys  

Microsoft Academic Search

AlMg and AlMgSi alloys are used for automotive applications, where a good corrosion resistance is required. Recently, there has been a growing interest in using strip casting as a method to produce low-cost aluminum sheet for automotive applications. The present work was undertaken to investigate the corrosion behavior of twin-roll cast AA5754 and AA6016 sheet for panel applications, on the

Feriha Birol; Yucel Birol

2004-01-01

476

Damage and ductility of particulate and short-fibre Al?Al 2O 3 composites  

Microsoft Academic Search

The mechanical behaviour of 2014 and 6061 Al-alloy composites is investigated as a function of matrix treatment (T4 and T6 temper) and reinforcement shape (Al2O3 short fibres and particulates). Comparisons are carried out amongst the composites and with the corresponding unreinforced alloys and are mainly focused on the attained strength and ductility levels as influenced by damage accumulation and fracture

M. Vedani; E. Gariboldi

1996-01-01

477

An Approximation of Action Theories of AL \\\\mathcal{AL} and Its Application to Conformant Planning  

Microsoft Academic Search

\\u000a In this paper we generalize the notion of approximation of action theories introduced in [13,26]. We introduce a logic programming\\u000a based method for constructing approximation of action theories of AL\\\\mathcal{AL} and prove its soundness. We describe an approximation based conformant planner and compare its performance with other state-of-the-art\\u000a conformant planners.

Tran Cao Son; Phan Huy Tu; Michael Gelfond; A. Ricardo Morales

478

Defect Band Characteristics in Mg-Al and Al-Si High-Pressure Die Castings  

Microsoft Academic Search

Bands of positive macrosegregation and porosity commonly follow the surface contour of components produced by high-pressure\\u000a die casting (HPDC). In this article, Al alloy AlSi7Mg and Mg alloys AZ91 and AM60 were cast into tensile test bars using cold-chamber\\u000a (cc) HPDC. Microstructural characterization revealed that externally solidified crystals (ESCs) are not necessary for defect\\u000a band formation, and that defect bands

C. M. Gourlay; H. I. Laukli; A. K. Dahle

2007-01-01

479

Defect Band Characteristics in Mg-Al and Al-Si High-Pressure Die Castings  

Microsoft Academic Search

Bands of positive macrosegregation and porosity commonly follow the surface contour of components produced by high-pressure die casting (HPDC). In this article, Al alloy AlSi7Mg and Mg alloys AZ91 and AM60 were cast into tensile test bars using cold-chamber (cc) HPDC. Microstructural characterization revealed that externally solidified crystals (ESCs) are not necessary for defect band formation, and that defect bands

C. M. Gourlay; H. I. Laukli; A. K. Dahle

2007-01-01

480

PVD Coating of Mg–AZ31 by Thin Layer of Al and Al–Si  

Microsoft Academic Search

Although magnesium alloys have the advantage of high specific strength, they have poor atmospheric corrosion resistance. An\\u000a important method of improving the corrosion resistance is by applying a coating layer. In this work, the physical vapor deposition\\u000a (PVD) technique is used for coating a magnesium (Mg) AZ31 sheet substrate with a thin layer of high purity aluminum (Al) and\\u000a Al–12.6%

Mohamed A. Taha; Nahed A. El-Mahallawy; Rawia M. Hammouda; Sherif I. Nassef

2010-01-01

481

High-speed InGaAlAs\\/InAlAs multiple quantum well optical modulators  

Microsoft Academic Search

High-speed modulation over 22 GHz for waveguided InGaAlAs\\/InAlAs multiple quantum well (MQW) optical modulators is described. A large on\\/off ratio of over 25 dB is demonstrated with a low-drive voltage (6 V) operating in the 1.55-?m wavelength region. The design and characteristics of MQW p-i-n modulators are discussed. The causes of large-insertion loss and the required drive voltage bandwidth figure

Koichi Wakita; Isamu Kotaka; Osamu Mitomi; Hiromitsu Asai; Yuichi Kawamura; Mitsuru Naganuma

1990-01-01

482

Differential corticospinal tract degeneration in homozygous ‘D90A’ SOD1 ALS and sporadic ALS  

Microsoft Academic Search

BackgroundThe homogeneous genotype and stereotyped phenotype of a unique familial form of amyotrophic lateral sclerosis (ALS) (patients homozygous for aspartate-to-alanine mutations in codon 90 (homD90A) superoxide dismutase 1) provides an ideal model for studying genotype\\/phenotype interactions and pathological features compared with heterogeneous apparently sporadic ALS. The authors aimed to use diffusion tensor tractography to quantify and compare changes in the

C R V Blain; S Brunton; V C Williams; A Leemans; M R Turner; P M Andersen; M Catani; B R Stanton; J Ganesalingham; D K Jones; S C R Williams; P N Leigh; A Simmons

2011-01-01

483

Tensile properties and fracture characteristics of ECAP-processed Al and Al-Cu alloys  

Microsoft Academic Search

In the present paper, billets of pure Al, and cast-homogenized Al-2 wt.%, 3 wt.%, and 5 wt.% Cu alloys were successfully processed\\u000a by equal channel angular pressing (ECAP) up to 10 passes without fracture at room temperature using a die with a channel angle\\u000a of 110°. Giant strains imposed on workpieces lead to extreme dislocation densities, microstructural refinement, and finally

Mohamed Ibrahim Abd El Aal; Nahed El Mahallawy; Farouk A. Shehata; Mohamed Abd El Hameed; Eun Yoo Yoon; Jung Hwan Lee; Hyoung Seop Kim

2010-01-01

484

Al nanogrid electrode for ultraviolet detectors.  

PubMed

Optical properties of Al nanogrids of different pitches and gaps were investigated both theoretically and experimentally. Three-dimensional finite-difference time-domain simulation predicted that surface plasmons at the air/Al interface would enhance ultraviolet transmission through the subwavelength gaps of the nanogrid, making it an effective electrode on GaN-based photodetectors to compensate for the lack of transparent electrode and high p-type doping. The predicted transmission enhancement was verified by confocal scanning optical microscopy performed at 365 nm. The quality of the nanogrids fabricated by electron-beam lithography was verified by near-field scanning optical microscopy and scanning electron microscopy. Based on the results, the pitch and gap of the nanogrids can be optimized for the best trade-off between electrical conductivity and optical transmission at different wavelengths. Based on different cutoff wavelengths, the nanogrids can also double as a filter to render photodetectors solar-blind. PMID:21931425

Ding, G; Deng, J; Zhou, L; Gan, Q; Hwang, J C M; Dierolf, V; Bartoli, F J; Mazuir, C; Schoenfeld, W V

2011-09-15