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1

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

2

Industrial wastes and sludges management by vermicomposting  

Microsoft Academic Search

Vermicomposting has been arising as an innovative ecotechnology for the conversion of various types of wastes into vermicompost.\\u000a Vermicompost is humus like, finely granulated and stabilized material which can be used as a soil conditioner to reintegrate\\u000a the organic matter to the agricultural soils. Industrial wastes remain largely unutilized and often cause environmental problems\\u000a like ground and surface water pollution,

Anoop Yadav; V. K. Garg

3

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

4

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...

5

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

6

Bioremediation of Agricultural Wastes through Vermicomposting  

Microsoft Academic Search

The post-harvest residues of some local crops, e.g., wheat (Triticum aestivum), millets (Penniseum typhoides and Sorghum vulgare), and a pulse (Vigna radiata) were subjected to recycle through vermicomposting. The crop residues were amended with animal dung, and three types of vermibeds were prepared: (i) millet straw (S. vulgare + P. typhoides in equal quantity) + sheep manure (1: 2 ratio)

Surindra Suthar

2009-01-01

7

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

8

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

9

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

10

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

11

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

12

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

13

Spectroscopic analysis of vermicompost for determination of nutritional quality.  

PubMed

Spectroscopic analysis has been carried out to examine the compost quality, maturity and nutritional levels of vermicompost and compost of Eichhornia. 50% Eichhorniacrassipes and 50% cow dung mixtures were vermicomposted using earthworms (Eudrilus eugeniae) and collected on different days' time intervals. Fourier transform infrared spectroscopy (FT-IR) spectra reveal the presence of humic substance from compost and vermicompost, which improves the soil fertility. Gas chromatography-mass spectroscopy (GC-MS) analysis shows maximum level of Benzene propanoic acid (95.98%) and by 2-Propanone, 1-Phenyl-, OXIM (10.10%) from vermicompost through earthworms activity. Atomic absorption spectroscopy (AAS) results reported high level of micronutrient from Eichhornia mediated compost and vermicompost. PMID:25068838

Subhash Kumar, M; Rajiv, P; Rajeshwari, Sivaraj; Venckatesh, Rajendran

2015-01-25

14

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

2012-01-01

15

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

16

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.

17

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

18

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

19

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

Microsoft Academic Search

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

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

2011-01-01

20

Microbiological characterization of vermicomposts by the method of multisubstrate testing  

NASA Astrophysics Data System (ADS)

A new modification of the method of multisubstrate testing (MST, BIOLOG) is suggested. It is based on the kinetic description of bacterial growth on nutrient media during 50 h. The results of the MST represent a set of three parameters (the initial optical density, the maximum specific growth rate, and the maximum optical density) of an equation describing the growth of microbial communities on individual substrates. Methods of multivariate statistics (cluster and discriminant analyses) have been used to compare these parameters for 24 organic substrates. It is supposed that a more detailed description of the growth of microorganisms should improve the information capacity of the MST method. The effect of earthworms on vermicomposting has been studied experimentally with the MST method. An empirical rule allowing one to distinguish between vermicomposts and ordinary composts using the results of MST is suggested. Manure, earthy matter from the intestinal tracts of earthworms ( Eisenia andrei), and their coprolites have been subjected to MST. A functional similarity between manure and fresh coprolites has been found. Also, three different lots of industrial vermicomposts have been compared. The cluster analysis has demonstrated a significant difference between them. The clusters depend on the nature of the initial substrates used for preparing these vermicomposts. Thus, unification of the initial substrates used for composting is necessary to obtain standardized vermicomposts.

Yakushev, A. V.; Byzov, B. A.

2008-11-01

21

The potential reuse of biodegradable municipal solid wastes (MSW) as feedstocks in vermicomposting.  

PubMed

There is an urgent need globally to find alternative sustainable steps to treat municipal solid wastes (MSW) originated from mismanagement of urban wastes with increasing disposal cost. Furthermore, a conglomeration of ever-increasing population and consumerist lifestyle is contributing towards the generation of more MSW. In this context, vermicomposting offers excellent potential to promote safe, hygienic and sustainable management of biodegradable MSW. It has been demonstrated that, through vermicomposting, MSW such as city garbage, household and kitchen wastes, vegetable wastes, paper wastes, human faeces and others could be sustainably transformed into organic fertiliser or vermicompost that provides great benefits to agricultural soil and plants. Generally, earthworms are sensitive to their environment and require temperature, moisture content, pH and sometimes ventilation at proper levels for the optimum vermicomposting process. Apart from setting the optimum operational conditions for the vermicomposting process, other approaches such as pre-composting, inoculating micro-organisms into MSW and redesigning the conventional vermireactor could be introduced to further enhance the vermicomposting of MSW. Thus the present mini-review discusses the potential of introducing vermicomposting in MSW management, the benefits of vermicomposted MSW to plants, suggestions on how to enhance the vermicomposting of MSW as well as risk management in the vermicomposting of MSW. PMID:20718020

Sim, Edwin Yih Shyang; Wu, Ta Yeong

2010-10-01

22

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

23

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

2011-07-01

24

[Effects of herb residue vermicompost on maize growth and soil fertility].  

PubMed

A pot experiment was conducted to evaluate the effects of herb residue vermicompost on maize growth and soil fertility. With the increasing application rate of vermicompost, the plant height, stem diameter, leaf area, and chlorophyll content of maize all increased significantly. After 60 days growth of maize, the soil bulk density in most vermicompost treatments decreased significantly. The soil pH in vermicompost treatments was significantly higher than that in CK and in chemical fertilization treatments. In addition, the soil total nitrogen and organic matter contents in vermicompost treatments were obviously higher than those in chemical fertilization treatments. It was suggested that herb residue vermicompost could be used as an efficient and high-quality organic fertilizer, and its appropriate application could improve soil physical structure, alleviate soil acidification, increase soil organic matter and nitrogen contents, and promote crop growth. PMID:24417126

Li, Jing-Juan; Zhou, Bo; Zhang, Chi; Zhang, Jing; Xu, Huan; Yang, Xiao-Xue; Chen, Xu-Fei; Dai, Jun

2013-09-01

25

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

2011-11-01

26

Interested in Earthworms? Want to learn about both good and bad ones? Tempted to try your hand at vermicomposting?  

E-print Network

at vermicomposting? NOW IS YOUR CHANCE!!! Come join us for OUR FREE PROGRAM FEATURING: Dr. Josef Gorres from & Garden Education Center VERMICOMPOSTING 101 Lisa Krall, Natural Resouces Conservation Service BUILD YOUR

Holsinger, Kent

27

Chitinophaga eiseniae sp. nov., isolated from vermicompost.  

PubMed

A Gram-negative, rod-shaped bacterial strain, YC6729(T), was isolated from vermicompost collected at Masan, Korea, and its taxonomic position was investigated by a polyphasic taxonomic approach. Strain YC6729(T) grew optimally at 30 °C and at pH 6.5-8.5. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YC6729(T) belongs to the genus Chitinophaga in the family Chitinophagaceae. It was related most closely to Chitinophaga terrae KP01(T) (96.4?% 16S rRNA gene sequence similarity), Chitinophaga ginsengisegetis Gsoil 040(T) (96.1?%), Chitinophaga arvensicola IAM 12650(T) (96.1?%) and Chitinophaga pinensis DSM 2588(T) (93.3?%). Strain YC6729(T) contained MK-7 as the major menaquinone and homospermidine as the major polyamine. The fatty acids of strain YC6729(T) were iso-C(15?:?0), C(16?:?1)?5c, iso-C(17?:?0) 3-OH, C(16?:?0), anteiso-C(18?:?0) and/or C(18?:?2)?6,9c, iso-C(15?:?0) 2-OH and/or C(16?:?1)?7c, C(14?:?0), iso-C(15?:?0) 3-OH, iso-C(15?:?1) G, C(18?:?1)?5c, iso-C(15?:?1) I and/or C(13?:?0) 3-OH, C(13?:?0) 2-OH, C(16?:?0) 3-OH and unknown fatty acid ECL 13.565. The polar lipid profile contained phosphatidylethanolamine, unknown aminolipids and unknown lipids. The total DNA G+C content of strain YC6729(T) was 48.9 mol%. The phenotypic, chemotaxonomic and phylogenetic data showed that strain YC6729(T) represents a novel species of the genus Chitinophaga, for which the name Chitinophaga eiseniae sp. nov. is proposed. The type strain is YC6729(T) (?=?KACC 13774(T) ?=?DSM 22224(T)). PMID:21057055

Yasir, Muhammad; Chung, Eu Jin; Song, Geun Cheol; Bibi, Fehmida; Jeon, Che Ok; Chung, Young Ryun

2011-10-01

28

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

29

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. PMID:17910115

Nourbakhsh, Farshid

2007-01-01

30

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

2010-12-01

31

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

32

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

33

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

34

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

35

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

36

Treated-cassava peel vermicomposts enhanced earthworm activities and cowpea growth in field plots  

Microsoft Academic Search

The peels of bitter cassava (Manihot utilissima) root, a major source of food carbohydrate in the tropics, though rich in nutrients, form toxic wastes lethal to soil invertebrates and can inhibit root growth. Recent investigations highlighted the ability of the earthworm, Eudrilus eugeniae (Eug) to partially detoxify the toxic wastes, and transform the cassava peels into valuable vermicompost. Vermicomposting and

1996-01-01

37

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

38

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

Microsoft Academic Search

Vermicomposts processed commercially from food wastes and paper wastes were applied, to 4.5 m2 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,

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

2004-01-01

39

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

40

Evaluation of vermicompost maturity using scanning electron microscopy and paper chromatography analysis.  

PubMed

Vermicompost was produced from flower waste inoculated with biofertilizers using the earthworm Eisenia fetida. Principal component analysis (PCA) and cluster analysis (CA) were carried out on the basis of physicochemical parameters of vermicomposted samples. From the results of the PCA and CA, it was possible to classify two different groups of vermicompost samples in the following categories: E2 and E5; and E1, E3, E4, and control. Scanning electron microscopy and biodynamic circular paper chromatography analysis were used to investigate the changes in surface morphology and functional groups in the control and vermicompost products. SEM analysis of E1-E5 shows more fragment and pores than the control. Chromatographic analysis of vermicompost indicated the mature condition of the compost materials. PMID:24634991

Senthil Kumar, D; Satheesh Kumar, P; Rajendran, N M; Uthaya Kumar, V; Anbuganapathi, G

2014-04-01

41

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

2011-03-01

42

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

2011-06-01

43

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

2012-04-01

44

Changes in fungal population of fly ash and vinasse mixture during vermicomposting by Eudrilus eugeniae and Eisenia fetida: documentation of cellulase isozymes in vermicompost.  

PubMed

Fly ash (FA) and vinasse (VN), two industrial wastes, are generated in huge amounts and cause serious hazards to the environment. In this experiment, different proportions of these two wastes were used as food for two epigeic earthworms (Eisenia fetida and Eudrilus eugeniae) to standardize the recycling technique of these two wastes and to study their effect on fungal especially cellulolytic fungal population, cellulase activity and their isozyme pattern, chitin content and microbial biomass of waste mixture during vermicomposting. Increasing VN proportion from 25% to 50% or even higher, counts of both fungi and cellulolytic fungi in waste mixtures were significantly (P ? 0.05) increased during vermicomposting. Higher cellulase activity in treatments having 50% or more vinasse might be attributed to the significantly (P ? 0.05) higher concentration of group I isozyme while concentrations of other isozymes (group II and III) of cellulase were statistically at par. Higher chitin content in vinasse-enriched treatments suggested that fungal biomass and fungi-to-microbial biomass ratio in these treatments were also increased due to vermicomposting. Results revealed that Eudrilus eugeniae and Eisenia fetida had comparable effect on FA and VN mixture during vermicomposting. Periodical analysis of above-mentioned biochemical and microbial properties and nutrient content of final vermicompost samples indicated that equal proportion (1:1, w/w) of FA and VN is probably the optimum composition to obtain best quality vermicompost. PMID:21277188

Pramanik, Prabhat; Chung, Young Ryun

2011-06-01

45

Effects of combined composting and vermicomposting of waste sludge on arsenic fate and bioavailability.  

PubMed

Composting and vermicomposting are traditional processes for the treatment of sludge. During these processes, the humification of organic matter has a significant effect on the physicochemical form and distribution of heavy metals. In this study, industrial sludge (groundwater treatment waste) contaminated by arsenic (396 ± 1 mg kg(-1)) was used. Such sludge poses a significant challenge with respect to effective treatment. Composting, vermicomposting (with Eisenia fetida), and the combined approach of composting and vermicomposting were performed to determine the evolution of arsenic speciation, mobility and bioavailability. The composting/vermicomposting was done with sludge, horse manure, and grass in the ratios of 3:6:1. A solution of 0.1M NH4COOCH3 was used as a single extraction solvent for determination of the mobile arsenic pool and targeted arsenic species (As(III), As(V), monomethylarsenic acid - MMA(V), dimethylarsenic acid - DMA(V)). The analysis of arsenic in the extracts was carried out by means of HPLC-ICP-MS spectrometry. In addition, the earthworm species E. fetida was used for bioaccumulation tests that followed the compost and vermicompost processes. The obtained results indicate a reduction in arsenic mobility and bioavailability in all matured composts and vermicomposts. The combined process exhibited a greater effect than compost or vermicompost alone. PMID:25209831

Ma?áková, Blanka; Kuta, Jan; Svobodová, Markéta; Hofman, Jakub

2014-09-15

46

Copper, nickel and zinc accumulations in lettuce grown in soil amended with contaminated cattle manure vermicompost after sequential cultivations.  

PubMed

The Cu, Ni and Zn accumulations in leaves and roots of lettuce (Lactuca sativa L) grown in soil amended with natural and contaminated cattle manure vermicompost were evaluated. The vermicompost residues containing relatively high metal concentrations used in this work were obtained from a previous experiment, in which vermicompost was applied to removing metals from electroplating wastes. Sequential lettuce cultivations were conducted in pots containing the residual substrates from the first cultivation by adding metal-enriched vermicompost residues. In general, the Cu, Ni and Zn concentrations in leaves and roots of lettuce plants grown in vermicompost enriched with these metals were higher than in the treatment using the natural vermicompost. The metal concentrations in leaves from treatments with natural vermicompost were below the critical concentrations of toxicity to plants. However, the metal concentrations in leaves of the third cultivation in which metal-enriched vermicompost was applied were greater than the upper limit that causes plant toxicity, but no visual damage was observed in the plants. Treatment with Zn-enriched vermicompost resulted in toxicity symptoms, but plant damage did not result in the death of the plant. The chemical fractionation of Cu, Ni and Zn in residues from lettuce cultivation was evaluated by using a sequential extraction procedure and metal concentrations were increased in the different chemical fractions according to the increase of vermicompost dose. PMID:23837328

Jordão, Cláudio P; de Andrade, Renato P; Cotta, Aloísio J B; Cecon, Paulo R; Neves, Júlio C L; Fontes, Mauricio P F; Fernandes, Raphael B A

2013-01-01

47

Use of DGGE and COMPOCHIP for investigating bacterial communities of various vermicomposts produced from different wastes under dissimilar conditions.  

PubMed

This study describes the use of denaturing gradient gel electrophoresis (DGGE) and COMPOCHIP (i.e. a microarray targeting typical bacteria of stabilized organic materials and pathogenic bacteria) for investigating the bacterial communities of four different vermicomposts. These included a commercial vermicompost produced from cattle manure (CM) and three vermicomposts produced at pilot-scale by recycling: damaged tomato fruits (DT); olive-mill waste mixed with biosolids (OB); and winery wastes (WW). DGGE provided distinctive fingerprints of each vermicompost, which were statistically related to their particular chemical features. The comparison of the various vermicompost fingerprints showed that they contained bacterial communities with an average similarity coefficient of close to 80%. COMPOCHIP detected the presence of Sphingobacterium, Streptomyces, Alpha-Proteobacteria, Delta-Proteobacteria, and Firmicutes in all the vermicomposts. COMPOCHIP showed differences in the abundance of particular bacterial taxa among the vermicomposts, giving an idea about the usefulness of each vermicompost in the search for bacteria valuable to biotechnology. The joint use of DGGE and COMPOCHIP is a useful tool to compare vermicompost bacterial communities and to assess the potential of different vermicomposts as bioactive organic materials. PMID:22154215

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

2012-01-01

48

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

2011-10-01

49

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

2013-11-01

50

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

2013-10-01

51

Vermicomposting of wastewater sludge from paper-pulp industry with nitrogen rich materials  

Microsoft Academic Search

The vermicomposting of pulp mill sludge mixed with sewage sludge, pig slurry and poultry slurry at different ratios was studied. Eisenia andrei (Bouché, 1972) showed high growth rates and high mortalities in all the mixtures considered.

C. Elvira; L. Sampedro; J. Dominguez; S. Mato

1997-01-01

52

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

53

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

54

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

55

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

56

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

57

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

58

Towards understanding the stabilization process in vermicomposting using PARAFAC analysis of fluorescence spectra.  

PubMed

In this study, fluorescence excitation-emission matrix (EEM) combined with parallel factor analysis (PARAFAC) was employed to trace the behavior of water extractable organic matter and assess the stabilization process during vermicomposting of sewage sludge and cattle dung. Experiments using different mixing ratios of sewage sludge and cattle dung were conducted using Eisenia fetida. The results showed that vermicomposting reduced the DOC, DOC/DON ratio and ammonia, while increased the nitrate content. A three-component model containing two humic-like materials (components 1 and 2) and a protein-like material (component 3) was successfully developed using PARAFAC analysis. Moreover, the initial waste composition had a significant effect on the distribution of each component and the addition of cattle dung improved the stability of sewage sludge in vermicomposting. The PARAFAC results also indicated that protein-like materials were degraded and humic acid-like compounds were evolved during vermicomposting. Pearson correlation analysis showed that components 2 and 3 are more suitable to assess vermicompost maturity than component 1. In all, EEM-PARAFAC can be used to track organic transformation and assess biological stability during the vermicomposting process. PMID:25068534

Lv, Baoyi; Xing, Meiyan; Zhao, Chunhui; Yang, Jian; Xiang, Liang

2014-12-01

59

Ethylene removal evaluation and bacterial community analysis of vermicompost as biofilter material.  

PubMed

Biofiltration of ethylene provides an environmentally friendly and economically beneficial option relative to physical/chemical removal, where selection of appropriate bed material is crucial. Here the vermicompost with indigenous microorganisms as bed material was evaluated for ethylene removal through batch test and biofilter experiment. Temporal and spatial dynamics of bacterial community in the vermicompost-biofilter under different ethylene loads were characterized by culture and denaturing gradient gel electrophoresis (DGGE) methods. The results showed that ethylene was effectively degraded by the vermicompost under conditions of 25-50% moisture content and 25-35°C temperature. The vermicompost-biofilter achieved nearly 100% ethylene removal up to an inlet load of 11mg m(-3)h(-1). Local nitrogen lack of the vermicompost in the biofilter was observed over operation time, but the change of pH was slight. DGGE analysis demonstrated that the bacterial abundance and community structure of vermicompost-biofilter varied with the height of biofilter under different ethylene loads. Pseudomonads and Actinobacteria were predominant in the biofilter throughout the whole experiment. PMID:21665363

Fu, Yuming; Shao, Lingzhi; Liu, Hui; Tong, Ling; Liu, Hong

2011-08-30

60

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

61

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

62

Impact of Parthenium weeds on earthworms (Eudrilus eugeniae) during vermicomposting.  

PubMed

The aim of this work is to evaluate the effect of Parthenium-mediated compost on Eudrilus eugeniae during the process of vermicomposting. Nine different concentrations of Parthenium hysterophorus and cow dung mixtures were used to assess toxicity. The earthworms' growth, fecundity and antioxidant enzyme levels were analysed every 15 days. The antioxidant activities of enzymes [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)], considered as biomarkers, indicate the biochemical and oxidative stresses due to the toxin from Parthenium weeds. The earthworms' growth, biomass gain, cocoon production and antioxidant enzymes were in a low level in a high concentration of P. hysterophorus (without cow dung). The results clearly indicated that appropriate mixing of P. hysterophorus quantity is an essential factor for the survival of earthworms without causing any harm. PMID:24938809

Rajiv, P; Rajeshwari, Sivaraj; Rajendran, Venckatesh

2014-11-01

63

Heavy metal behavior and dissolved organic matter (DOM) characterization of vermicomposted pig manure amended with rice straw.  

PubMed

Vermicomposting is an eco-friendly method for disposing of livestock and poultry manure. In addition, dissolved organic matter (DOM) can serve as a carrier that enhances the migration and transformation of heavy metals. Here, pig manure amended with rice straw was vermicomposted with Eisenia fetida. The DOM content, molecular weight distribution, and spectroscopic properties of the amended pig manure were measured before and after vermicomposting. The Cu and Zn concentrations in the earthworms increased from 8.24 and 17.63 to 40.75 and 362.78 mg/kg separately after vermicomposting, and the earthworms also increased the heavy metal availability in the vermicompost. Relative to the DOM properties of conventional compost, the DOM molecular weight decreased and varied widely following vermicomposting, and the C/N ratio of the DOM in the vermicompost treatments decreased from 10.37 to 8.60. The Fourier transform far-infrared (FTIR) and fluorescence spectra of the DOM indicated that the amounts of oxygen-containing structures increased while the ratio of humic acid to fulvic acid decreased following vermicomposting. Accordingly, the earthworms augmented the heavy metal mitigation risk in the pig manure. This augment potentially resulted from the decreased humic acid-to-fulvic acid (HA/FA) ratio from DOM structural changes. PMID:24958537

Zhu, Weiqin; Yao, Wu; Zhang, Zhi; Wu, Yang

2014-11-01

64

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

PubMed

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. PMID:23998948

Rajiv, P; Rajeshwari, Sivaraj; Venckatesh, Rajendran

2013-12-01

65

Carbon and nitrogen mineralization in a vineyard soil amended with grape marc vermicompost.  

PubMed

Vineyard soils in many areas suffer from low organic matter contents, which can be the cause of negative effects such as increasing the risk of erosion, so the use of organic amendments must be considered a good agricultural practice. Even more, if grape marc is recycled as a soil amendment in the vineyards, benefits from a good waste management strategy are also obtained. In the present study, a grape marc from the wine region of Valdeorras (north-west Spain) was used for the production of vermicompost, and this added to a vineyard soil of the same area in a laboratory study. Mixtures of soil and grape marc vermicompost (2 and 4%, dry weight) were incubated for ten weeks at 25°C and the mineralization of C and N studied. The respiration data were fitted to a first-order kinetic model. The rates of grape marc vermicompost which should be added to the vineyard soil in order to maintain the initial levels of organic matter were estimated from the laboratory data, and found to be 1.7?t?ha(-1)?year(-1) of bulk vermicompost (if the present mean temperature is considered) and 2.1?t?ha(-1)?year(-1) of bulk vermicompost (if a 2°C increment in temperature is considered), amounts which could be obtained recycling the grape marc produced in the exploitation. PMID:20837558

Paradelo, Remigio; Moldes, Ana Belén; Barral, María Teresa

2011-11-01

66

Insight into the roles of earthworm in vermicomposting of sewage sludge by determining the water-extracts through chemical and spectroscopic methods.  

PubMed

This work illustrated the effects of earthworm in vermicomposting (Eisenia fetida) by determining the water-extracts through chemical and spectroscopic methods. A field experiment with sludge as the only feed was subjected to vermicomposting and the control (without worms) for three weeks. Compared to the control, vermicomposting resulted in lower pH and water-extractable organic carbon (WEOC) along with higher electrical conductivity (EC). Moreover, vermicomposting caused nearly two times higher content of water-extractable nitrate (WEN-NO3(-)) than the control. Furthermore, fourier transform infrared spectra (FT-IR) revealed that vermicomposting promoted the hydrolysis/transformation of macromolecular organic matters and accelerated the degradation of polysaccharide-like and protein-like materials. Fluorescence spectroscopy also reflected vermicomposting led to higher humification degree than the control. In all, this study supplies a new view to assess the roles of earthworm in vermicomposting of sewage sludge by evaluating the water extracts. PMID:24384315

Yang, Jian; Lv, Baoyi; Zhang, Jie; Xing, Meiyan

2014-02-01

67

Molecular characteristics of humic acids isolated from vermicomposts and their relationship to bioactivity.  

PubMed

Vermitechnology is an effective composting method, which transforms biomass into nutrient-rich organic fertilizer. Mature vermicompost is a renewable organic product containing humic substances with high biological activity. The aim of this study was to assess the chemical characteristics and the bioactivity of humic acids isolated from different vermicomposts produced with either cattle manure, sugar cane bagasse, sunflower cake from seed oil extraction, or filter cake from a sugar cane factory. More than 200 different molecules were found, and it was possible to identify chemical markers on humic acids according to the nature of the organic source. The large hydrophobic character of humic extracts and the preservation of altered lignin derivatives confer to humic acids the ability to induce lateral root emergence in maize seedlings. Humic acid-like substances extracted from plant biomass residues represent an additional valuable product of vermicomposting that can be used as a plant growth promoter. PMID:25379603

Martinez-Balmori, Dariellys; Spaccini, Riccardo; Aguiar, Natália Oliveira; Novotny, Etelvino Henrique; Olivares, Fábio Lopes; Canellas, Luciano Pasqualoto

2014-11-26

68

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

2013-05-01

69

Changes of carbon, nitrogen, phosphorous, and potassium content during storage of vermicomposts prepared from different substrates.  

PubMed

The study was conducted to determine the optimum storage time for vermicompost without significant loss of nutrients; nitrogen (N), phosphorous (P), and potassium (K). Cattle manure, paddy straw, municipal solid wastes, and fly ash were used for vermicompost preparations. The dynamics of N, P, and K in the vermicomposts were studied during 180 days of incubation at 28-32 °C. In general, N concentration increased in the first 90-105 days of incubation and then gradually decreased until the 180th day while P and K concentrations steadily decreased over the length of the study, with the rate of loss leveling off after 150 days. The rate of nutrient loss was directly related to the initial level, decreasing the fastest for the nutrients with the highest initial concentrations. Optimum storage times were substrate and N dependent. PMID:25208521

Das, D; Powell, Michael; Bhattacharyya, P; Banik, P

2014-12-01

70

An overview of the environmental applicability of vermicompost: from wastewater treatment to the development of sensitive analytical methods.  

PubMed

The use of vermicompost (humified material) for treating wastewaters, remediating polluted soils, improving agricultural productivity, protecting crop production, and developing sensitive analytical methods is reviewed here, covering the past 17 years. The main advantages of vermicompost, considering all applications covered in this paper, comprise (i) easy acquisition, (ii) low costs, (iii) structural, chemical, and biological characteristics responsible for exceptional adsorptive capacities as well as pollutant degradation, and (iv) the promotion of biocontrol. Specifically, for wastewater decontamination, a considerable number of works have verified the adsorption of toxic metals, but the application of vermicompost is still scarce for the retention of organic compounds. Problems related to the final disposal of enriched vermicompost (after treatment steps) are often found, in spite of some successful destinations such as organic fertilizer. For decontaminating soils, the use of vermicompost is quite scarce, mainly for inorganic pollutants. In agricultural productivity and biocontrol, vermicompost imparts remarkable benefits regarding soil aggregation, plant nutrition, and the development of beneficial microorganisms against phytopathogens. Finally, the use of vermicompost in sensitive analytical methods for quantifying toxic metals is the newest application of this adsorbent. PMID:24578668

Pereira, Madson de Godoi; Neta, Lourdes Cardoso de Souza; Fontes, Maurício Paulo Ferreira; Souza, Adriana Nascimento; Matos, Thaionara Carvalho; Sachdev, Raquel de Lima; dos Santos, Arnaud Victor; da Guarda Souza, Marluce Oliveira; de Andrade, Marta Valéria Almeida Santana; Paulo, Gabriela Marinho Maciel; Ribeiro, Joselito Nardy; Ribeiro, Araceli Verónica Flores Nardy

2014-01-01

71

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

72

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

73

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

74

“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

75

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

76

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

77

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

78

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

79

Municipal solid waste (MSW) vermicomposting with an epigeic earthworm, Perionyx ceylanensis Mich.  

PubMed

Municipal solid waste (MSW) was vermicomposted in combination with cowdung (CD) using Perionyx ceylanensis for 50 days. The decomposition rate of 55-78% was observed in different vermibed substrates, the highest being CD followed by 10:1 ratio of CD+MSW. The C/N ratio was reduced from 41.8 to 17.6 and 38.8 to 15.4 in MSW+CD (10:1) and CD, respectively. The difference in the final C/N ratio between MSW+CD (10:1) and CD vermicompost was not significant (p<0.05). The important nutrients, NPK showed significantly (p<0.05) higher contents in vermicomposts than worm-unworked composts. The degradation rate of cellulose and lignin was 37% and 12%, respectively, in 10:1 vermibed mix with P. ceylanensis. The bacterial, fungal and actinomycetes population in vermicompost was significantly higher than in the compost. The biomass, number and cocoons of P. ceylanensis collected after 50 days showed increase with the increase of CD incorporation in MSW. PMID:21511467

Paul, J A John; Karmegam, N; Daniel, Thilagavathy

2011-06-01

80

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

81

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

82

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

83

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

84

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

85

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

86

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

2012-05-01

87

Local lettuce: heat tolerant romaine cultivars and vermicompost soil amendment to increase sustainability in the Mid-Atlantic .  

E-print Network

??Local production of lettuce in the Mid-Atlantic utilizing heat-tolerant romaine cultivars and vermicompost soil amendment has the potential to significantly increase sustainability of agriculture. Heat… (more)

Wallis, Anna Elizabeth

2014-01-01

88

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

89

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

90

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

2011-06-01

91

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

92

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

2012-02-29

93

Short-term effects of combined iprodione and vermicompost applications on soil microbial community structure.  

PubMed

The use of compost amendments to bioremediate potential organic pollutants in agricultural soils has recently become an increasingly important field of research. Although several fungicides have been extensively used to control a wide range of soil-borne fungal diseases, little is known about the impact of applying these pesticides on the structure and function of microbial communities in soils amended with vermicompost. The aim of this study was to evaluate the effect of a combined treatment of iprodione and vermicompost on soil microbiological parameters under laboratory conditions. The study was carried out on agricultural and grassland soils to identify the effect of iprodione application at field rate (FR) and 10-times FR (10 FR) with and without vermicompost (VCH) on iprodione breakdown, fluorescein diacetate activity (FDA), total fatty acid methyl ester (FAME) profiles, total protein content, and protein profiles by using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Our results indicate that the addition of vermicompost decreased the iprodione breakdown at days 30 and 60 in non-sterilised agricultural soil and at 60 days in sterilised and non-sterilised grassland soil. Independent of vermicompost amended treatments, iprodione was found to mainly alter microbial communities after 30 days of incubation. On day 30, separation between communities treated with iprodione 10 FR and iprodione 10FR + VCH treatments were well defined in both agricultural and grassland soils. Within each soil type, our results showed no difference in the total protein content. However, the protein content in the grassland soil was clearly higher than in the agricultural soil. SDS-PAGE gels revealed that the treatments applied to the agricultural soil using iprodione at the highest dosages (iprodione 10FR and iprodione 10FR+VCH) resulted in an alteration of the band pattern. In conclusion, the experiments revealed that the addition of vermicompost may decrease the breakdown of iprodione in soils. Furthermore, elevated dosages of iprodione may potentially affect the microbial community structure and diversity of the soil, which may lead to the deterioration of soil quality and fertility. PMID:22115616

Verdenelli, Romina A; Lamarque, Alicia L; Meriles, José M

2012-01-01

94

Capacity of Various Food Materials to Support Growth and Reproduction of Epigeic Earthworms on Vermicompost  

Microsoft Academic Search

Biomass production and reproduction of tropical epigeic earthworms (Eisenia fetida, Perionyx excavatus, and Dicogaster bolaui) were studied using in-situ vermicomposts to assess the suitability of different forest litters, i.e., Tectona grandis(teak), Madhuca indica(mahua), and Butea monosperma (palas) and crop residues, i.e., Triticum aestivum L. (wheat), Glycine max Merri. L. (soybean), and Brasica juncea L. (mustard) as food materials. The leaf

M. C. Manna; S. Jha; P. K. Ghosh; T. K. Ganguly; K. N. Singh; P. N. Takkar

2005-01-01

95

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

96

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

97

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

98

Microbiological community analysis of vermicompost tea and its influence on the growth of vegetables and cereals.  

PubMed

Vermicompost, the digestion product of organic material by earthworms, has been widely reported to have a more positive effect on plant growth and plant health than conventional compost. A study was conducted to investigate the effects of different vermicompost elutriates (aerated compost teas) on soils and plant growth. The teas were analyzed by chemical, microbiological, and molecular methods accompanied by plant growth tests at laboratory and field scale. The number of microorganisms in the teas increased during the extraction process and was affected by substrate addition. The vermicompost tea found to increase plant growth best under laboratory tests was applied to cereals (wheat and barley) and vegetables (Raphanus sativus, Rucola selvatica, and Pisum sativum) in a field study. The results revealed no effects of tea application on plant yield; however, sensoric tests indicated an improvement in crop quality. The soils from laboratory and field studies were investigated to detect possible microbial or chemical changes. The results indicated that minor changes to the soil microbial community occurred following tea application by foliar spray in both the laboratory-scale and field-scale experiments. PMID:22712623

Fritz, J I; Franke-Whittle, I H; Haindl, S; Insam, H; Braun, R

2012-07-01

99

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

PubMed

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 municipal sources. This study was conducted to determine if the effluent solids from a large recirculating aquaculture facility (Blue Ridge Aquaculture, Martinsville, Virginia) were suitable for vermicomposting using the earthworm Eisenia fetida. In two separate experiments, worms were fed mixtures of solids removed from aquaculture effluent (sludge) and shredded. Mixtures containing 0%, 5%, 10%, 15%, 20%, 25%, and 50% aquaculture sludge (dry weight basis) were fed to the worms over a 12-week period and their growth (biomass) was measured. Worm mortality, which occurred only in the first experiment, was not influenced by feedstock sludge concentration. In both experiments worm growth rates tended to increase with increasing sludge concentration, with the highest growth rate occurring with feedstocks containing 50% aquaculture sludge. Effluent solids from recirculating aquaculture systems mixed with shredded cardboard appear to be suitable feedstocks for vermicomposting. PMID:15491821

Marsh, Lori; Subler, Scott; Mishra, Sudanshu; Marini, Michele

2005-03-01

100

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

2012-01-01

101

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

2012-08-01

102

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

2013-12-01

103

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

2010-12-01

104

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

105

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; Velásquez Vargas, Gabriela; Mora Gil, Maria de la Luz; Dang, Dinh-Kim; Jouquet, Pascal

2013-11-01

106

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

107

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

2013-09-01

108

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

2013-06-01

109

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

2012-01-01

110

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

111

Attenuation of veterinary antibiotics in full-scale vermicomposting of swine manure via the housefly larvae (Musca domestica).  

PubMed

Animal waste from concentrated swine farms is widely considered to be a source of environmental pollution, and the introduction of veterinary antibiotics in animal manure to ecosystems is rapidly becoming a major public health concern. A housefly larvae (Musca domestica) vermireactor has been increasingly adopted for swine manure value-added bioconversion and pollution control, but few studies have investigated its efficiency on antibiotic attenuation during manure vermicomposting. In this study we explored the capacity and related attenuation mechanisms of antibiotic degradation and its linkage with waste reduction by field sampling during a typical cycle (6 days) of full-scale larvae manure vermicomposting. Nine antibiotics were dramatically removed during the 6-day vermicomposting process, including tetracyclines, sulfonamides, and fluoroquinolones. Of these, oxytetracycline and ciprofloxacin exhibited the greater reduction rate of 23.8 and 32.9?mg m(-2), respectively. Environmental temperature, pH, and total phosphorus were negatively linked to the level of residual antibiotics, while organic matter, total Kjeldahl nitrogen, microbial respiration intensity, and moisture exhibited a positive effect. Pyrosequencing data revealed that the dominant phyla related to Firmicutes, Bacteroidetes, and Proteobacteria accelerated manure biodegradation likely through enzyme catalytic reactions, which may enhance antibiotic attenuation during vermicomposting. PMID:25354896

Zhang, ZhiJian; Shen, JianGuo; Wang, Hang; Liu, Meng; Wu, LongHua; Ping, Fan; He, Qiang; Li, HongYi; Zheng, ChangFeng; Xu, XinHua

2014-01-01

112

Attenuation of veterinary antibiotics in full-scale vermicomposting of swine manure via the housefly larvae (Musca domestica)  

NASA Astrophysics Data System (ADS)

Animal waste from concentrated swine farms is widely considered to be a source of environmental pollution, and the introduction of veterinary antibiotics in animal manure to ecosystems is rapidly becoming a major public health concern. A housefly larvae (Musca domestica) vermireactor has been increasingly adopted for swine manure value-added bioconversion and pollution control, but few studies have investigated its efficiency on antibiotic attenuation during manure vermicomposting. In this study we explored the capacity and related attenuation mechanisms of antibiotic degradation and its linkage with waste reduction by field sampling during a typical cycle (6 days) of full-scale larvae manure vermicomposting. Nine antibiotics were dramatically removed during the 6-day vermicomposting process, including tetracyclines, sulfonamides, and fluoroquinolones. Of these, oxytetracycline and ciprofloxacin exhibited the greater reduction rate of 23.8 and 32.9 mg m-2, respectively. Environmental temperature, pH, and total phosphorus were negatively linked to the level of residual antibiotics, while organic matter, total Kjeldahl nitrogen, microbial respiration intensity, and moisture exhibited a positive effect. Pyrosequencing data revealed that the dominant phyla related to Firmicutes, Bacteroidetes, and Proteobacteria accelerated manure biodegradation likely through enzyme catalytic reactions, which may enhance antibiotic attenuation during vermicomposting.

Zhang, Zhijian; Shen, Jianguo; Wang, Hang; Liu, Meng; Wu, Longhua; Ping, Fan; He, Qiang; Li, Hongyi; Zheng, Changfeng; Xu, Xinhua

2014-10-01

113

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

114

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

115

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

116

Vermicomposting potentiality of Perionyx excavatus for recycling of waste biomass of java citronella - An aromatic oil yielding plant  

Microsoft Academic Search

Laboratory investigation on vermicomposting efficacy of Perionyx excavatus for recycling of distillation waste biomass of java citronella (Cymbopogon winterianus Jowitt) was carried out in two seasonal trials i.e. summer and winter periods. The experiment was conducted in earthen pots using a mixture of citronella waste material and cowdung in the proportion of 5:1. A control treatment without earthworms was setup

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

2011-01-01

117

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

118

Effect of enzyme producing microorganisms on the biomass of epigeic earthworms (eisenia fetida) in vermicompost.  

PubMed

We analyzed the bacterial community structure of the intestines of earthworms and determined the effect of enzyme producing microorganisms on the biomass of earthworms in vermicompost. Fifty-seven bacterial 16S rDNA clones were identified in the intestines of earthworms by using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Entomoplasma somnilux and Bacillus licheniformis were the dominant microorganisms; other strains included Aeromonas, Bacillus, Clostridium, Ferrimonas, and uncultured bacteria. Among these strains, Photobacterium ganghwense, Aeromonas hydrophila, and Paenibacillus motobuensis were enzyme-producing microorganisms. In the mixtures that were inoculated with pure cultures of A. hydrophila WA40 and P. motobuensis WN9, the highest survival rate was 100% and the average number of earthworms, young earthworms, and cocoons were 10, 4.00-4.33, and 3.00-3.33, respectively. In addition, P. motobuensis WN9 increased the growth of earthworms and production of casts in the vermicompost. These results show that earthworms and microorganisms have a symbiotic relationship. PMID:21421302

Hong, Sung Wook; Lee, Ju Sam; Chung, Kun Sub

2011-05-01

119

The influence of earthworms on nutrient dynamics during the process of vermicomposting.  

PubMed

In the present study the potential of the earthworm Eisenia andrei to modify chemical and microbiological properties, with a special focus on the nutrient content of fresh organic matter, was evaluated during 16 weeks of vermicomposting of cattle manure and sewage sludge. Samples were periodically collected in order to determine the changes in inorganic nitrogen (N), in total microbial biomass and activity, as well as in the total and available content of macro- and micronutrients. An optimal moisture level, ranging from 75% to 88%, was maintained throughout the process. The content of organic matter decreased over time, but no changes were found in this parameter as a result of earthworm activity. The carbon/N ratio rapidly decreased, but only in the manure, reflecting rapid decomposition and mineralisation of the organic matter by the earthworms. An increase in N mineralisation was also attributable to the presence of earthworms, although in the manure this effect was hardly detectable before the eighth week of vermicomposting. Earthworm activity also enhanced the total content of potassium, calcium and iron together with an increase in the availability of phosphorus and zinc. We did not detect a significant earthworm effect on microbial respiration, but their activity increased greatly microbial biomass nitrogen in sewage sludge. PMID:23831778

Domínguez, Jorge; Gómez-Brandón, María

2013-08-01

120

Suppression of two-spotted spider mite ( Tetranychus urticae), mealy bug ( Pseudococcus sp) and aphid ( Myzus persicae) populations and damage by vermicomposts  

Microsoft Academic Search

A vermicompost, produced commercially from food wastes, was tested for its capacity to suppress populations and damage to plants, by two-spotted spider mites (Tetranychus urticae), mealy bugs (Pseudococcus sp.) and aphids (Myzus persicae), in the greenhouse. A range of mixtures of food waste vermicompost and a soil-less bedding plant growth medium Metro-Mix 360 (MM360) was tested in cages (40cm ×

Norman Q. Arancon; Clive A. Edwards; Erdal N. Yardim; Thomas J. Oliver; Robert J. Byrne; George Keeney

2007-01-01

121

[Organic waste treatment by earthworm vermicomposting and larvae bioconversion: review and perspective].  

PubMed

There is a growing attention on the environmental pollution and loss of potential regeneration of resources due to the poor handling of organic wastes, while earthworm vermicomposting and larvae bioconversion are well-known as two promising biotechnologies for sustainable wastes treatments, where earthworms or housefly larvae are employed to convert the organic wastes into humus like material, together with value-added worm product. Taken earthworm ( Eisenia foetida) and housefly larvae ( Musca domestica) as model species, this work illustrates fundamental definition and principle, operational process, technical mechanism, main factors, and bio-chemical features of organisms of these two technologies. Integrated with the physical and biochemical mechanisms, processes of biomass conversion, intestinal digestion, enzyme degradation and microflora decomposition are comprehensively reviewed on waste treatments with purposes of waste reduction, value-addition, and stabilization. PMID:23914515

Zhang, Zhi-jian; Liu, Meng; Zhu, Jun

2013-05-01

122

Effects of earthworms on physicochemical properties and microbial profiles during vermicomposting of fresh fruit and vegetable wastes.  

PubMed

This study aimed to investigate the effect of earthworms on physicochemical and microbial properties during vermicomposting of fresh fruit and vegetable wastes (FVW) by contrasting two decomposing systems of FVW with and without earthworms for 5weeks. Compared to control treatment (without earthworms), vermicomposting treatment resulted in a rapid decrease of electrical conductivity and losses of total carbon and nitrogen from the 2nd week. Quantitative PCR displayed that earthworms markedly enhanced bacterial and fungal densities, showing the higher values than control, during the whole decomposition process. In addition, denaturing gradient gel electrophoresis combined with sequencing analysis revealed that earthworms pronouncedly modified bacterial and fungal community structures, through broadening the community diversities of Actinobacteria, Bacteroidetes, Proteobacteria, and Ascomycotina. These results suggest that the presence of earthworms promoted the activity and population of bacteria and fungi, and modified their communities, thus altering the decomposition pathway of fresh FVW. PMID:25118152

Huang, Kui; Li, Fusheng; Wei, Yongfen; Fu, Xiaoyong; Chen, Xuemin

2014-10-01

123

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

124

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

125

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

2013-06-01

126

Short-Term Effect of Vermicompost Application on Biological Properties of an Alkaline Soil with High Lime Content from Mediterranean Region of Turkey  

PubMed Central

This study was conducted to investigate direct short-term impact of vermicompost on some soil biological properties by monitoring changes after addition of vermicompost as compared to farmyard manure in an alkaline soil with high lime content from semiarid Mediterranean region of Turkey. For this purpose, mixtures of soil and organic fertilizers in different doses were incubated under greenhouse condition. Soil samples collected in regular intervals were analyzed for biological parameters including dehydrogenase, ?-glucosidase, urease, alkaline phosphatase activities, and total number of aerobic mesophilic bacteria. Even though soil dehydrogenase activity appeared to be dose-independent based on overall evaluation, organic amendments were found to elevate dehydrogenase activity when sampling periods are evaluated individually. ?-glucosidase, urease, alkaline phosphatase activity, and aerobic mesophilic bacterial numbers in vermicompost treatments fluctuated but remained significantly above the control. A slight but statistically significant difference was detected between organic amendments in terms of urease activity. Vermicompost appeared to more significantly increase bacterial number in soil. Clearly, vermicompost has a potential to be used as an alternative to farmyard manure to improve and maintain soil biological activity in alkaline calcareous soils from the Mediterranean region of Turkey. Further studies are needed to assess its full potential for these soils. PMID:25254238

Uz, Ilker; Tavali, Ismail Emrah

2014-01-01

127

Short-term effect of vermicompost application on biological properties of an alkaline soil with high lime content from Mediterranean region of Turkey.  

PubMed

This study was conducted to investigate direct short-term impact of vermicompost on some soil biological properties by monitoring changes after addition of vermicompost as compared to farmyard manure in an alkaline soil with high lime content from semiarid Mediterranean region of Turkey. For this purpose, mixtures of soil and organic fertilizers in different doses were incubated under greenhouse condition. Soil samples collected in regular intervals were analyzed for biological parameters including dehydrogenase, ?-glucosidase, urease, alkaline phosphatase activities, and total number of aerobic mesophilic bacteria. Even though soil dehydrogenase activity appeared to be dose-independent based on overall evaluation, organic amendments were found to elevate dehydrogenase activity when sampling periods are evaluated individually. ?-glucosidase, urease, alkaline phosphatase activity, and aerobic mesophilic bacterial numbers in vermicompost treatments fluctuated but remained significantly above the control. A slight but statistically significant difference was detected between organic amendments in terms of urease activity. Vermicompost appeared to more significantly increase bacterial number in soil. Clearly, vermicompost has a potential to be used as an alternative to farmyard manure to improve and maintain soil biological activity in alkaline calcareous soils from the Mediterranean region of Turkey. Further studies are needed to assess its full potential for these soils. PMID:25254238

Uz, Ilker; Tavali, Ismail Emrah

2014-01-01

128

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

129

Heavy metal and nutrient changes during vermicomposting animal manure spiked with mushroom residues.  

PubMed

A pilot-scale trial of four months was conducted to investigate the responses of heavy metal and nutrient to composting animal manure spiked with mushroom residues with and without earthworms. Results showed that earthworm activities accelerated organic matter mineralization (e.g. reduction in C/N ratio, increase in total concentrations of N, P, K) and humification (e.g. increase in humic acid concentration, humification ratio and humification index). Despite composting increased total heavy metal (i.e. As, Pb, Cu, Zn) concentrations irrespective of earthworm, the availability of heavy metals extracted by DTPA significantly (P<0.05) decreased particularly in treatments with earthworms introduced. The shift from available to unavailable fractions of heavy metals was either due to earthworm bioaccumulation, as indicated by total heavy metal concentrations being higher in earthworm tissues, or due to the formation of stable metal-humus complexes as indicated by the promotion of humification. Our results suggest that vermicomposting process could magnify the nutrient quality but relieve the heavy metals risk of agricultural organic wastes. PMID:25128918

Song, Xiuchao; Liu, Manqiang; Wu, Di; Qi, Lin; Ye, Chenglong; Jiao, Jiaguo; Hu, Feng

2014-11-01

130

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

2012-01-01

131

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

132

Evaluation of vermicompost as bioadsorbent substrate of Pb, Ni, V and Cr for waste waters remediation using Total Reflection X-ray Fluorescence  

NASA Astrophysics Data System (ADS)

The use of vermicompost as adsorbent substrate for removing Pb, Ni, V and Cr from waste waters is proposed. In this work, after a preliminary physical and chemical characterization of the vermicompost, the optimal parameters for the heavy metal adsorption were obtained. A synthetic multielemental solution of Pb, Cr and Ni and a solution of NH 4VO 3 for vanadium were evaluated. The optimized parameters were pH, vermicompost mass to volume ratio, agitation time and particle size of the adsorbent. A batch system was employed for the assays. The elements were determined in the supernatant solution after filtration of the substrate. An optimal pH of 4.5 was found for ion removal. The agitation time slightly influences the adsorption of Pb and Cr, but it has a high influence on the Ni and V adsorption. The highest adsorption and removal of the metals was observed for a vermicompost mass of 2 g per 500 mL using a particle size between 75 to 841 µm for Pb, Cr and Ni, and 841 till 1192 µm for V. The mean removal percentage for each element is around 95% for Pb. Ni and Cr in the multielemental synthetic sample, demonstrating a high removal capacity of the substrate. For V it was found a removal efficiency of 50%.

Urdaneta, Cynthia; Parra, Lué-Merú Marcó; Matute, Saida; Garaboto, Mayantino Angel; Barros, Hayden; Vázquez, Cristina

2008-12-01

133

Vermicompost as a substitute for peat in potting media: Effects on germination, biomass allocation, yields and fruit quality of three tomato varieties  

Microsoft Academic Search

Commercial potting media often contain substantial amounts of peat that was mined from endangered bog and fen ecosystems. The main objectives of this study were to assess (1) whether the amendment of 0, 20, 40, 60, 80 and 100% (v\\/v) of vermicompost (VC) to a fertilized commercial peat potting substrate has effects on the emergence, growth and biomass allocation of

Johann G. Zaller

2007-01-01

134

Organic amendment based on vermicompost and compost: differences on soil properties and maize yield.  

PubMed

The objective of the present study was to study the effect of two vermicomposts [animal (VCD) and vegetal origin (VGF)] and a cotton gin compost (C) at rates of 1780 and 3560?kg fresh organic matter?ha(-1) for 3 years on an Typic Xerofluvent located near Seville (Spain) on soil biological properties, nutrition (leaf N, P and K concentration, pigments and soluble carbohydrate concentrations) and yield parameters of maize (Zea mays cv. Tundra) crop. All organic waste materials had a positive effect on the soil biological properties, plant nutrition and crop yield parameters, although at the end of the experimental period and at the high organic matter rate, the soil microbial biomass and dehydrogenase, urease, ?-glucosidase, phosphatase and arylsulfatase activities increased more significantly in the VCD-amended soils (86.4, 85.8, 94.5, 99.3, 70.1 and 63.8%, respectively) respect to the control soil, followed by VGF-amended soils (84.8, 80.6, 92.7, 99.1, 68.3 and 61.6%, respectively) and CC-amended soils (80.5, 75.9, 89.7, 99, 65.7 and 59.9%, respectively). Leaf N, P and K contents and pigments and soluble carbohydrate contents were highest in VCD-amended soils, followed by VGF and CC treatments. Compared with the control soil, the application of VCD in soils at high doses increased the crop yield parameters, followed by VGF and CC treatments. This may have been due to a greater labile fraction of organic matter in the VCD than the VGF and CC, respectively. PMID:20921058

Tejada, Manuel; Benítez, Concepción

2011-11-01

135

Bioremediation of Distillery Sludge into Soil-Enriching Material Through Vermicomposting with the Help of Eisenia fetida.  

PubMed

The aim of the present study was bioremediation of distillery sludge into a soil-enriching material. It was mixed with a complementary waste, cattle dung, and subjected to vermicomposting with (V) and without (T, control) Eisenia fetida in the ratio of 0:100 % (V1, T1), 10:90 (V2, T2), 25:75 (V3, T3), 50:50 (V4, T4), 75:25 (V5, T5) and 100:0 % (V6, T6), respectively. Survival rate, growth rate, onset of maturity, cocoon production and population build-up increased with increasing ratio of cattle dung. Maximum mortality of earthworm was observed in V6 mixture. On the basis of response surface design, the concentration of sludge giving highest number of worms, cocoons and hatchlings came out to be 21.11, 24.51 and 17.19 %, respectively. Nitrogen, phosphorus, sodium and pH increased during vermicomposting but decreased in the products without earthworm and there was increase in the contents of transition metals in the products of both the techniques. However, organic carbon, electrical conductivity and potassium showed an opposite trend. PMID:25113550

Singh, Jaswinder; Kaur, Arvinder; Vig, Adarsh Pal

2014-10-01

136

Treatment and biotransformation of highly polluted agro-industrial wastewater from a palm oil mill into vermicompost using earthworms.  

PubMed

In this laboratory-scale study, earthworms were introduced as biodegraders of palm oil mill effluent (POME), which is a wastewater produced from the wet process of palm oil milling. POME was absorbed into amendments (soil or rice straw) in different ratios as feedstocks for the earthworm, Eudrilus eugeniae. The presence of earthworms led to significant increases in pH, electrical conductivity, and nutrient content but decreases in the C/N ratio (0.687-75.8%), soluble chemical oxygen demand (19.7-87.9%), and volatile solids (0.687-52.7%). However, earthworm growth was reduced in all treatments by the end of the treatment process. Rice straw was a better amendment/absorbent relative to soil, with a higher nutrient content and greater reduction in soluble chemical oxygen demand with a lower C/N ratio in the vermicompost. Among all treatments investigated, the treatment with 1 part rice straw and 3 parts POME (w/v) (RS1:3) produced the best quality vermicompost with high nutritional status. PMID:24372356

Lim, Su Lin; Wu, Ta Yeong; Clarke, Charles

2014-01-22

137

Biodegradation of 3,4 dichloroaniline by fungal isolated from the preconditioning phase of winery wastes subjected to vermicomposting.  

PubMed

A hazardous contaminant, 3,4-dichloroaniline (DCA) is widespread in the environment due to its extensive use in the manufacture of chemicals and its application in different sectors. The ability of fungi grow on in winery wastes in the preconditioning period of vermicomposting to degrade DCA was investigated. Three filamentous fungi (F1, F2, and F3) were isolated and one identified as Aspergillus niger and two as Fusarium sp. strains. The culture media with the fungus alone or in consortium (Fmix) with DCA as the nitrogen source were analyzed by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC/MS). The fastest degradation rate was measured in Fmix with a DT50 of 0.85day(-1). Fusarium sp. and A. niger differed in the metabolism of DCA. Five metabolites were identified as a result of oxidation, co-denitrification, N-acetylation, and polymerization reactions. The major metabolites were 3,4-dichloroacetanilide and dichloroquinolines. The azo-metabolites tetrachloroazobenzene and tetracloroazoxybenzene and 3,4-dichloronitrobenzene were found in minor amounts but appeared to be the most persistent in the Fusarium cultures (half-lives ranging from 8.3 to 30.9 days). This study highlights the metabolic potential of microorganisms in the preconditioning period of the vermicomposting process and its possible application for in situ bioremediation strategies. PMID:24440653

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

2014-02-28

138

Assessing the impact of composting and vermicomposting on bacterial community size and structure, and microbial functional diversity of an olive-mill waste  

Microsoft Academic Search

The aim of this study was to couple biochemical and molecular methodologies for evaluating the impact of two recycling technologies (composting and vermicomposting) on a toxic organic waste. To do this, six enzyme activities controlling the key metabolic pathways of the breakdown of organic matter, real-time PCR assays targeting 16S rRNA genes, and denaturing gradient gel electrophoresis (DGGE) profiling-sequence analysis

A. Vivas; B. Moreno; S. Garcia-Rodriguez; E. Benitez

2009-01-01

139

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.

140

La educación superior en América Latina frente al desarrollo regional y la globalización  

Microsoft Academic Search

En este artículo se analiza el papel que ha venido desempeñando la universidad latinoamericana, particularmente la pública, en el contexto de desenvolvimiento de la educación superior, teniendo en cuenta el escenario económico neoliberal y las condiciones de gobernabilidad que enfrenta la región. Así mismo, se establece que el desarrollo científico y tecnológico es indispensable para lograr afectaciones positivas en el

Alberto Lemos Valencia

2004-01-01

141

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

142

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

143

Evaluation of Streptomyces strains isolated from herbal vermicompost for their plant growth-promotion traits in rice.  

PubMed

Six actinomycetes, CAI-13, CAI-85, CAI-93, CAI-140, CAI-155 and KAI-180, isolated from six different herbal vermi-composts were characterized for in vitro plant growth-promoting (PGP) properties and further evaluated in the field for PGP activity in rice. Of the six actinomycetes, CAI-13, CAI-85, CAI-93, CAI-140 and CAI-155 produced siderophores; CAI-13, CAI-93, CAI-155 and KAI-180 produced chitinase; CAI-13, CAI-140, CAI-155 and KAI-180 produced lipase; CAI-13, CAI-93, CAI-155 and KAI-180 produced protease; and CAI-13, CAI-85, CAI-140 and CAI-155 produced ß-1-3-glucanase whereas all the six actinomycetes produced cellulase, hydrocyanic acid and indole acetic acid (IAA). The actinomycetes were able to grow in NaCl concentrations of up to 8%, at pH values between 7 and 11, temperatures between 20 and 40 °C and compatible with fungicide bavistin at field application levels. In the rice field, the actinomycetes significantly enhanced tiller numbers, panicle numbers, filled grain numbers and weight, stover yield, grain yield, total dry matter, root length, volume and dry weight over the un-inoculated control. In the rhizosphere, the actinomycetes also significantly enhanced total nitrogen, available phosphorous, % organic carbon, microbial biomass carbon and nitrogen and dehydrogenase activity over the un-inoculated control. Sequences of 16S rDNA gene of the actinomycetes matched with different Streptomyces species in BLAST analysis. Of the six actinomycetes, CAI-85 and CAI-93 were found superior over other actinomycetes in terms of PGP properties, root development and crop productivity. qRT-PCR analysis on selected plant growth promoting genes of actinomycetes revealed the up-regulation of IAA genes only in CAI-85 and CAI-93. PMID:24113511

Gopalakrishnan, Subramaniam; Vadlamudi, Srinivas; Bandikinda, Prakash; Sathya, Arumugam; Vijayabharathi, Rajendran; Rupela, Om; Kudapa, Himabindu; Katta, Krishnamohan; Varshney, Rajeev Kumar

2014-01-20

144

Strong et al ALS FTD consensus criteria  

E-print Network

Strong et al ALS FTD consensus criteria 1 Version: 20070606 Frontotemporal syndromes in amyotrophic-663-3609 Email: mstrong@uwo.ca #12;Strong et al ALS FTD consensus criteria 2 Introduction Although amyotrophic

Dickerson, Brad

145

Al Composites  

NASA Astrophysics Data System (ADS)

In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of -45 to +5 and +45 to 100 ?m were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.

Chandanayaka, Tharaka; Azarmi, Fardad

2014-05-01

146

Amyotrophic Lateral Sclerosis (ALS)  

MedlinePLUS Videos and Cool Tools

Amyotrophic Lateral Sclerosis Introduction Amyotrophic Lateral Sclerosis, or ALS, is a serious neurological disease that affects the ability to ... com nr180104 Last reviewed: 03/20/2013 1 ALS ALS attacks the neurons that control muscles, the ...

147

About ALS: FAQ  

MedlinePLUS

... are the potential side effects? What Is ALS? Amyotrophic Lateral Sclerosis (ALS) is a motor neuron disease, first identified in ... neurologist Jean-Martin Charcot. Although the cause of ALS is not completely understood, recent years have brought ...

148

Amyotrophic Lateral Sclerosis (ALS)  

MedlinePLUS

NINDS Amyotrophic Lateral Sclerosis (ALS) Information Page Clinical Trials Natural History and Biomarkers of C9ORF72 ALS and FTD The ... Trials Organizations Additional resources from MedlinePlus What is Amyotrophic Lateral Sclerosis (ALS)? Amyotrophic lateral sclerosis (ALS), sometimes ...

149

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

150

/Cu-Al System  

NASA Astrophysics Data System (ADS)

Wettability and interfacial interaction of the Ta2O5/Cu-Al system were studied. Pure Cu does not wet the Ta2O5 substrate, and improved spreading is achieved when relatively a high fraction of the active element (~40 at.% Al) was added. The Al2O3 and AlTaO4 phases were observed at the Ta2O5/Cu-Al interface. A thermodynamic evaluation allowed us to suggest that the lack of wetting bellow 40 at.% Al is due to the presence of a native oxide, which covers the drop. The conditions of the native oxide decomposition and the formation of the volatile Al2O suboxide strongly depend on the vacuum level during sessile drop experiments and the composition of the Cu-Al alloy. In our case, Al contents greater than 40% provides thermodynamic conditions for the formation of Al2O (as a result of Al reaction with Al2O3) and the drop spreading. It was suggested that the final contact angle in the Ta2O5/Cu-Al system (50°) is determined by Ta adsorption on the newly formed alumina interlayer.

Kish, Orel; Froumin, Natalya; Aizenshtein, Michael; Frage, Nachum

2014-05-01

151

Amyotrophic Lateral Sclerosis (ALS)  

Microsoft Academic Search

ALS, commonly called Lou Gehrig's disease, is a devastating neurological dis- order characterized by selective upper and lower somatic, but not autonomic, motor neurone degeneration leading to paralysis and eventually death. The diagnosis of ALS requires the presence of both upper and lower motor neu- rone degeneration and progressive motor dysfunction. ALS occurs in 1 to 2.5 cases per 100,000

Chris G. Parsons; Wojciech Danysz

152

Nuevos aspectos de la reacción entre el aminal macrocíclico 1:3,7:9,13:15,19:21-tetrametilentetrahexahidropirimidina (TMTP) frente a fenoles p-halogenados en condiciones “solvent free”.  

E-print Network

??Trujillo Pérez, Ginna Paola (2012) Nuevos aspectos de la reacción entre el aminal macrocíclico 1:3,7:9,13:15,19:21-tetrametilentetrahexahidropirimidina (TMTP) frente a fenoles p-halogenados en condiciones “solvent free”. Maestría… (more)

Trujillo Pérez, Ginna Paola

2012-01-01

153

ALS: AN ETHICAL PERSPECTIVE  

Microsoft Academic Search

Amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, is a relentlessly progressive, fatal and presently incurable motor neuron disorder caused by degeneration of both upper and lower neurons that control voluntary skeletal muscle. ALS variants include a progressive lower motor neuron disorder, Progressive Muscular Atrophy (PMA); a progressive upper motor neuron disorder, Primary Lateral Sclerosis (PLS); and a progressive disorder

Leo McCluskey

154

[Environmental factors in ALS].  

PubMed

ALS is likely to be a disorder of multifactorial origin. Among all the factors that may increase the risk of ALS, environmental ones are being studied for many years, but in the recent years, several advances have pointed to a new interest in their potential involvement in the disease process, especially for the cyanotoxin BMAA. Food containing BMAA has been found on Guam, a well-known focus of ALS/parkinsonism/dementia and high levels of BMAA have been identified into the brain of these patients. The BMAA cyanotoxin is potentially ubiquitous and have also been found into the food of patients who died from ALS both in Europe and USA. BMAA can be wrongly integrated into the protein structure during mRNA traduction, competing with serine. This may induce abnormal protein folding and a subsequent cell death. Heavy metals, such as lead or mercury may be directly toxic for neuronal cells. Several works have suggested an increased risk of ALS in individuals chronically exposed to these metals. Exposure to pesticides has been suggested to be linked to an increased risk of developing ALS. The mechanism of their toxicity is likely to be mediated by paraoxonases. These proteins are in charge of detoxifying the organism from toxins, and particularly organophosphates. To date, there are insufficient scientific data to suggest that exposure to electromagnetic fields may increase the risk of having ALS. We are particularly missing longitudinal cohorts to demonstrate that risk. PMID:24703731

Juntas-Morales, Raul; Pageot, Nicolas; Corcia, Philippe; Camu, William

2014-05-01

155

Primary AL Amyloidosis  

MedlinePLUS

... AL amyloidosis is a hematological disorder, associated with plasma cell dyscrasia that means an abnormal condition of ... fibrils, formed by an errant (monoclonal) group of plasma cells in the bone marrow, consist of abnormal ...

156

Malnutrition in ALS  

MedlinePLUS

... weakened tongue can make it difficult to swallow. Anorexia and depression may also contribute to the patient’s ... difficulty swallowing and/or breathing, constipation, pressure sores, anorexia, fatigue, spasms and confusion. ALS patients particularly susceptible ...

157

Advanced aerospace Al alloys  

Microsoft Academic Search

SiC particulate or whisker-reinforced aluminum alloys are very attractive for applications requiring high stiffness coupled with a comparatively light weight. The dispersion strengthened Al alloys produced through the rapid solidification processing\\/powder metallurgy route demonstrate superior elevated temperature strength and microstructural stability, extending the useful service temperature of Al alloys to 350 C. However, low ductility and poor fracture toughness levels

K. S. Ravichandran; E. S. Dwarakadasa

1987-01-01

158

ALS superbend magnet performance  

SciTech Connect

The Lawrence Berkeley National Laboratory has been engaged in the design, construction and testing of four superconducting dipoles (Superbends) that are installed in three arcs of the Advanced Light Source (ALS), with the fourth magnet as a spare. This represents a major upgrade to the ALS providing an enhanced flux and brightness at photon energies above 10 keV. In preparation for installation, an extensive set of tests and measurements have been conducted to characterize the magnetic and cryogenic performance of the Superbends and to fiducialize them for accurate placement in the ALS storage ring. The magnets are currently installed, and the storage ring is undergoing final commissioning. This paper will present the results of magnetic and cryogenic testing.

Marks, Steve; Zbasnik, John; Byrne, Warren; Calais, Dennis; Chin, Michael; DeMarco, Richard; Fahmie, Michael; Geyer, Alan; Krupnick, Jim; Ottens, Fred; Paterson, James A.; Pipersky, Paul; Robin, David S.; Schlueter, RossD.; Steier, Christoph; Wandesforde, Alan

2001-12-10

159

Rapidly solidified NiAl and FeAl  

NASA Technical Reports Server (NTRS)

Melt spinning was used to produce rapidly solidified ribbons of the B2 intermetallics NiAl and FeAl. Both Fe-40Al and Fe-45Al possessed some bend ductility in the as spun condition. The bend ductility of Fe-40Al, Fe-45Al, and equiatomic NiAl increased with subsequent heat treatment. Heat treatment at approximately 0.85 T (sub m) resulted in significant grain growth in equiatomic FeAl and in all the NiAl compositions. Low bend ductility in both FeAl and NiAl generally coincided with intergranular failure, while increased bend ductility was characterized by increasing amounts of transgranular cleavage fracture.

Gaydosh, D. J.; Crimp, M. A.

1984-01-01

160

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

161

Al Shanker Remembers.  

ERIC Educational Resources Information Center

In a 1996 interview shortly before his death, Al Shanker, longtime president of the American Federation of Teachers, discussed such topics as: his own educational experiences; how he learned about political fighting in the Boy Scouts; the appeal of socialism; multinational corporations and the nation state; teaching tough students; and John Dewey…

American Educator, 2000

2000-01-01

162

Smith et al Supporting Information  

E-print Network

Smith et al 1 Supporting Information for Smith et al. 2006, PLoS Computational Biology 2:e161-hyperpallium apicale; HF-hippocampal formation, and M-mesopallium. #12;Smith et al 2 FigureS2,nolinkswerefoundbetweenelectrodesindifferentbirds,andnolinkswerefoundintothesoundstimulusvariable. CombinedAnalysisofAllBirds'ElectrodesPlusSound #12;Smith et al 3 Analysis of Data from Subsections

Jarvis, Erich D.

163

/Al-Si Composite  

NASA Astrophysics Data System (ADS)

The cyclic fatigue characteristics of spray-deposited SiCp/Al-Si composite were investigated in comparison with the unreinforced Al-Si alloy. The as-extruded specimens were cyclically deformed with fully reversed loading under a range of total strain amplitudes. The results show that the cyclic response characteristics for the reinforced and unreinforced materials are similar to each other. Both the composite and matrix alloys display cyclic hardening under total strain amplitude of 0.35-0.5%. Otherwise, the composite exhibits higher degree of strain hardening than that of the matrix alloy. Dislocation substructure developed during cyclic deformation was analyzed using transmission electron microscopy. The discrepancy between dislocation substructures obtained from processing compared to its development during cyclic strain loading is thought to give rise to the observed cyclic stress response behavior. Fractographic analysis shows that particle/matrix debonding and particle cracking are the main mechanisms of failure in the SiC particle-reinforced composite.

Li, Wei; Chen, Jian; Hu, Yongle; Cong, Li; Sun, YouPing; Yang, JiMing

2014-08-01

164

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

165

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

166

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

167

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

168

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

169

THARYAN ET AL'S REPLY  

E-print Network

The comment by Dr. Andrade raising the possibility of missed subclinical fractures as a complication of unmodified ECT in some patients in our study is valid as patients were investigated radiographically only on clinical indication. Ihe aim of the study, however, was to survey the frequency of clinically significant physical complications. Crush fractures of the vertebrae, whether overt or covert, caused during unmodified electrconvulsivc therapy are clinically of little significance. They were frequently overlooked in the early years after the introduction of convulsive therapy as they were often painless or only caused transient pain that was often mistaken for myalgia. There were also no sequelae and no treatment was required (Kiloh et al,

unknown authors

170

Al Jazirah, Sudan  

NASA Technical Reports Server (NTRS)

Al Jazirah (also Gezira) is one of the 26 states of Sudan. The state lies between the Blue Nile and the White Nile in the east-central region of the country. It is a well populated area suitable for agriculture. The area was at the southern end of Nubia and little is known about its ancient history and only limited archaeological work has been conducted in this area. The region has benefited from the Gezira Scheme, a program to foster cotton farming begun in 1925. At that time the Sennar Dam and numerous irrigation canals were built. Al Jazirah became the Sudan's major agricultural region with more than 2.5 million acres (10,000 km) under cultivation. The initial development project was semi-private, but the government nationalized it in 1950. Cotton production increased in the 1970s but by the 1990s increased wheat production has supplanted a third of the land formerly seeded with cotton.

The image was acquired December 25, 2006, covers an area of 56 x 36.4 km, and is located near 14.5 degrees north latitude, 33.1 degrees east longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

2008-01-01

171

Submicron Nb-Al/Al oxide-Nb tunnel junctions sandwiched between Al films  

NASA Astrophysics Data System (ADS)

A process has been developed to embed Nb-Al/Al oxide-Nb junctions in planar structures of Al films. The submicron junctions are defined by photoresist lines. Motivation for this effort is a possible application of Nb junctions confined between normal conducting Al films as mixers above 700 GHz where Nb films loose their superconductive properties and tuning circuits made out of Nb therefore exhibit losses. First mixer results at 816 GHz are presented.

Maier, D.; Rothermel, H.; Gundlach, K. H.; Zimmermann, R.

1996-02-01

172

Microstructure and Mechanical Properties of HoAl-Al2O3\\/Ti Al Composite  

Microsoft Academic Search

HoAl-Al2O3\\/TiAl composites were fabricated by in-situ reaction synthesis using Al, Ti, TiO2 and Ho2O3 powders as raw materials. The effects of Ho2O3 content on the microstructure and mechanical properties of the composites were investigated. The phase constitution and microstructure of the composites were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicate that the ultimate phases

Hongya Xu; Fen Wang; Jianfeng Zhu; Yuxing Xie

2011-01-01

173

Descenso al Infierno de VenusDescenso al Infierno de VenusDescenso al Infierno de VenusDescenso al Infierno de Venus Manuel Alfonseca  

E-print Network

Descenso al Infierno de VenusDescenso al Infierno de VenusDescenso al Infierno de VenusDescenso al Infierno de Venus Manuel Alfonseca #12;Manuel Alfonseca 2 #12;Descenso al infierno de Venus 3 Descenso al infierno de Venus Manuel Alfonseca RESERVADOS TODOS LOS DERECHOS. Salvo usos razonables destinados al

Alfonseca, Manuel

174

Alexandria (Al Iskandariya), Egypt  

NASA Technical Reports Server (NTRS)

This image of Alexandria was taken by astronauts on board the International Space Station in December 2000 using an Electronic Still Camera. A wider-angle view (STS088-739-90) taken from the Space Shuttle in December 1998 is available for context. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. Originally the town was built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos (see referenced website, below) to the mainland. Since then sedimentary deposits have widened the mole. Since 1905, when the 370,000 Alexandrians lived in an area of about 4 sq km between the two harbors, the city (population 4 million; see referenced website, below) has grown beyond its medieval walls and now occupies an area of about 300 sq km. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon. Reference Youssef Halim and Fatma Abou Shouk, 2000, Human impacts on Alexandria's marine environment: UNESCO, Coastal Regions and Small Islands Unit (CSI), Coastal Management Sourcebooks 2 (accessed December 20, 2000) Additional photographs taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth. Image ISS001-ESC-5025 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

2002-01-01

175

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

176

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

177

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

178

Thin Films Using Al Doping  

NASA Astrophysics Data System (ADS)

We have studied the influence of Al doping on the microstructural, optical, and electrical properties of spray-deposited WO3 thin films. XRD analyses confirm that all the films are of polycrystalline WO3 in nature, possessing monoclinic structure. EDX profiles of the Al-doped films show aluminum peaks implying incorporation of Al ions into WO3 lattice. On Al doping, the average crystallite size decreases due to increase in the density of nucleation centers at the time of film growth. The observed variation in the lattice parameter values on Al doping is attributed to the incorporation of Al ions into WO3 lattice. Enhancement in the direct optical band gap compared to the undoped film has been observed on Al doping due to decrease in the width of allowed energy states near the conduction band edge. The refractive indices of the films follow the Cauchy relation of normal dispersion. Electrical resistivity compared to the undoped film has been found to increase on Al doping.

Mukherjee, Ramnayan; Prajapati, C. S.; Sahay, P. P.

2014-09-01

179

Allegato "B" DOMANDA DI PARTECIPAZIONE AL CONCORSO DI AMMISSIONE AL  

E-print Network

IN ROBOTICA, NEUROSCIENZE, NANOTECNOLOGIE E SCOPERTA FARMACI IN COLLABORAZIONE CON LA FONDAZIONE IIT Si prega'ammissione al Corso di Dottorato di Ricerca in Robotica, Neuroscienze, Nanotecnologie e Scoperta Farmaci

Sandini, Giulio

180

[ALS and excitatory amino acid].  

PubMed

AMPA receptor, one of ionotropic glutamate receptors, has been proposed to play a critical role to initiate the neuronal death cascade in motor neuron disease by an increase of Ca2+ influx. There are at least two mechanisms to increase Ca2+ influx through Ca2+-permiable AMPA receptor: a decrease of RNA editing efficacy at the GluR2 Q/R site and a decrease of GluR2 level relative to AMPA receptor subunits. Deficient RNA editing of the AMPA receptor subunit GluR2 at the Q/R site is a primary cause of neuronal death and recently has been reported to be a tightly linked etiological cause of motor neuron death in sporadic amyotrophic lateral sclerosis (ALS). On the other hand, relative low GluR2 level among AMPA receptor subunits seems to increase Ca2+ permeability of motor neurons in familial ALS (ALS1) linked to mutated cupper-zinc superoxide dismutase gene (SOD1). AMPA receptor-mediated mechanism does not seem to play any role in death of motor neurons in X-linked spinal and bulbar muscular atrophy (SBMA). From the molecular pathomechanism of sporadic ALS and ALS1, drugs which increase RNA editing efficacy at the GluR2 Q/R site could be a potent therapy for sporadic ALS, while AMPA receptor antagonists could prevent deterioration from ALS1. PMID:17969352

Aizawa, Hitoshi; Kwak, Shin

2007-10-01

181

Synthesis, processing and characterization of NiAl-AlN-Al(2)O(3) composites  

NASA Astrophysics Data System (ADS)

A hybrid composite based on nickel aluminide (NiAl) was developed, which contains both aluminum nitride (AlN) dispersoids and short alumina (Alsb2Osb3) fibers, with the strategy being the combination of the two different strengthening mechanisms, one microscopic and the other macroscopic, to provide a synergistic improvement in the mechanical properties. The AlN dispersion strengthened NiAl was synthesized by mechanical alloying of nickel and aluminum elemental powders in a nitrogen atmosphere and the alumina fibers were added during consolidation. The microstructure of the NiAl-(AlN)sb{Dispersion}-(Alsb2Osb3)sb{Fiber} composites showed a fine grain sized, near-stoichiometric NiAl matrix, submicron size AlN particles and randomly oriented Alsb2Osb3 fibers dispersed homogeneously in the matrix. The thermal residual stresses in the composites were measured at room temperature as well as at high temperatures using neutron diffraction and Rietveld refinement. The residual stresses in the as-processed composites were tensile in the NiAl matrix and compressive in the AlN and Alsb2Osb3 reinforcements. Upon heating these stresses relaxed at temperatures that are lower than the processing temperature due to the creep in the matrix. A simple finite element analysis was used to estimate the residual stress in the composites and showed reasonable agreement with the experimental results. The compressive strength of these composites was characterized both at 300K and 1300K and showed a significant strengthening compared with the base material at both temperatures. The relationship between the microstructure, residual stress and the mechanical properties was studied and the strengthening mechanisms were identified.

Choo, Hahn

182

Modeling of the ALS linac  

SciTech Connect

The ALS injector linac is used for the Beam Test Facility (BTF) and the Damping Experiments when it is available in between the ALS filings. These experiments usually require higher quality beams and a better characterization than is normally required for ALS operations. This paper focuses on the beam emittance, energy tilt, and especially the longitudinal variation of the beam parameters. For instance, the authors want to avoid longitudinal variations at the low beta section of the BTF. On the other hand, a large energy tilt is required for post-acceleration compression of the bunch using an alpha magnet. The PARMELA code was modified to calculate and display longitudinal variations of the emittance ellipse. Using the Microsoft Development Studio under Windows NT environment the code can handle a much larger number of particles than was previously possible.

Kim, C.H. [Lawrence Berkeley Lab., CA (United States). Advanced Light Source Center

1996-08-01

183

-and -Coordinated Al in AlC2 . A Combined  

E-print Network

/Al/Si composite target, respectively, with a pure helium carrier gas, and detected by a time-of-flight mass energies: 355 (3.496 eV) and 266 nm (4.661 eV). Photoelectron time-of-flight spectra were measured neutral species. The experiments were carried out with a magnetic- bottle time-of-flight PES apparatus

Simons, Jack

184

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

185

A nuclear magnetic resonance probe of Fe-Al and Al20V2Eu intermetallics  

E-print Network

Al-rich Fe-Al systems (FeAl2, Fe2 Al5 and Fe4Al13) and Al20V2Eu have complicated structures with quasicrystal-like features making these materials potentially of interest for magnetic behavior. However, there is not much work on these materials...

Chi, Ji

2009-05-15

186

Dynamic Modeling of ALS Systems  

NASA Technical Reports Server (NTRS)

The purpose of dynamic modeling and simulation of Advanced Life Support (ALS) systems is to help design them. Static steady state systems analysis provides basic information and is necessary to guide dynamic modeling, but static analysis is not sufficient to design and compare systems. ALS systems must respond to external input variations and internal off-nominal behavior. Buffer sizing, resupply scheduling, failure response, and control system design are aspects of dynamic system design. We develop two dynamic mass flow models and use them in simulations to evaluate systems issues, optimize designs, and make system design trades. One model is of nitrogen leakage in the space station, the other is of a waste processor failure in a regenerative life support system. Most systems analyses are concerned with optimizing the cost/benefit of a system at its nominal steady-state operating point. ALS analysis must go beyond the static steady state to include dynamic system design. All life support systems exhibit behavior that varies over time. ALS systems must respond to equipment operating cycles, repair schedules, and occasional off-nominal behavior or malfunctions. Biological components, such as bioreactors, composters, and food plant growth chambers, usually have operating cycles or other complex time behavior. Buffer sizes, material stocks, and resupply rates determine dynamic system behavior and directly affect system mass and cost. Dynamic simulation is needed to avoid the extremes of costly over-design of buffers and material reserves or system failure due to insufficient buffers and lack of stored material.

Jones, Harry

2002-01-01

187

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

188

Phase equilibria between NiAl and RuAl in the Ni-Al-Ru system  

SciTech Connect

Phase equilibria between NiAl and RuAl in Ni-Al-Ru alloys were studied by means of light microscopy and scanning electron microscopy. The JEOL JSM-35CF instrument was used in the electron probe microanalyses. The results indicate that the miscibility gap between NiAl and RuAl extends up to the solidus. The lattice parameter mismatch between the coexisting solid solutions based on NiAl and RuAl at temperatures of 1273 K and above is less than 0.6 percent. 10 references.

Chakravorty, S.; West, D.R.F.

1985-11-01

189

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

190

Ab? al-usayn al-Bar? and his Transmission of Biblical Materials from Kit?b al-D?n wa-al-Dawla by Ibn Rabban al-abar?: The Evidence from Fakhr al-D?n al-R?z?'s Maf?t? al-ghayb  

Microsoft Academic Search

The authenticity of the Kit?b al-d?n wa-al-dawla by the Nestorian convert to Islam, Ab? al-asan ?Al? b. Sahl Rabban al-abar? (d. ca. 251\\/865), has been discussed since the publication of the text by A. Mingana in 1922\\/23. A comparison between the chapter of the Twelver Sh??? Sad?d al-D?n Mam?d b. ?Al? al-imma? al-R?z?'s (d. after 600\\/1204) Munqidh min al-taql?d discussing

Sabine Schmidtke

2009-01-01

191

Al in computer games: Survey and perspectives  

Microsoft Academic Search

Computer games have traditionally implemented empirical solutions to many Al problems and are now turning to more traditional Al algorithms. After introducing the role of Al in gameplay, we review the main techniques used in current computer games such as Finite-State Transition Networks, rule-based systems and search algorithms. We describe the implementation of Al in several commercial computer games, as

M. Cavazza

2000-01-01

192

Tunneling through Al/AlOx/Al junction: Analytical models and first-principles simulations  

NASA Astrophysics Data System (ADS)

Ultrathin AlOx layers are nowadays widely employed to make tunneling junctions and, as a common practice, experimental transport data are often rationalized in terms of analytical models invoking effective electronic and geometric properties of the oxide layer. In this paper we examine the reliability of such models by performing first-principles simulations of the transport properties of Al/AlOx/Al junctions. The band gap, effective mass, and interface width obtained from ground state density-functional calculations are used within a potential barrier model, known also as the Simmons model, and its predictions of the conductance are compared with first-principles results. We also propose an analytical expression for the conductance based on a tight-binding model of the interface oxide. We show that the success of the potential barrier model in fitting experimental transport measurements rests on its formal similarity with the tight binding model which, in contrast to the former, is directly related to the realistic electronic structure of the interface.

Zemanová Diešková, M.; Ferretti, A.; Bokes, P.

2013-05-01

193

Inhibition of Al-induced root elongation and enhancement of Al-induced peroxidase activity in Al-sensitive and Al-resistant barley cultivars are positively correlated  

Microsoft Academic Search

The quantitative changes in peroxidase activity and composition of anionic and cationic isoperoxidases were investigated in roots of two barley cultivars differing in Al resistance. Root growth of Al-resistant cv. Bavaria was in lesser extent reduced by Al treatment (23% after 24 h Al-treatment), whereas 40% reduction of the root growth was observed in Al-sensitive cv. Alfor. The strong root

Ladislav Tamás; Jana Huttová; Igor Mistrík

2003-01-01

194

Applied Kinesiology als funktionelle Neurologie  

Microsoft Academic Search

Die muskuläre Diagnostik und Therapie, die noch vor einigen Jahren als die Domäne der Physiotherapie angesehen wurde, hält\\u000a erfreulicherweise mehr und mehr Einzug in die ärztliche Manualtherapie. Und auch hier setzt sich das Bewußtsein durch, dass\\u000a Knochen von Muskeln bewegt werden und es nicht ausreicht, Gelenke zu manipulieren, sondern dass ebenso die sie bewegenden\\u000a Muskeln behandelt werden müssen. Oder, nach

H. Garten

2000-01-01

195

Al-Hadith Text Classifier  

Microsoft Academic Search

This study explore the implementation of a text classification method to classify the prophet Mohammed (PBUH) hadiths (sayings) using Sahih Al-Bukhari classification. The sayings explain the Holy Qur`an, which considered by Muslims to be the direct word of Allah. Present method adopts TF\\/IDF (Term Frequency-Inverse Document Frequency) which is used usually for text search. TF\\/IDF was used for term weighting,

Mohammed Naji Al-Kabi; Ghassan Kanaan; Riyad Al-Shalabi; Saja I. Al-Sinjilawi; Ronza S. Al-Mustafa

2005-01-01

196

Al-Hadith Text Classifier  

Microsoft Academic Search

This study explores the implementation of a text classification method to classify the prophet Mohammed (PBUB) hadiths (sayings) using Sahih Al-Bukhari classification. The sayings explain the Holy Qur'an, which considered by Muslims to be the direct word of Allah. Present method adopts TF\\/IDF (Term Frequency-Inverse Document Frequency) which is used usually for text search. TF\\/IDF was used for term weighting,

Mohammed Naji Al-Kabi

2005-01-01

197

Nucleants of Eutectic Silicon in Al-Si Hypoeutectic Alloys: ?-(Al, Fe, Si) or AlP Phase  

NASA Astrophysics Data System (ADS)

A thermodynamic description of the Al-Si-P-Fe quaternary system focused on Al-(Si)-rich alloys is developed. The solidification sequence in typical Al-7Si cast alloys is derived using thermodynamic calculations of the phase diagrams and solidification simulation under Scheil and constrained Scheil conditions. The previously claimed nucleation of eutectic silicon by ?-(Al,Fe,Si) particles is not possible because under all conditions, ?-(Al,Fe,Si) precipitates after (Si) in pertinent alloys. Variation of P in the ppm range is crucial because it changes the solidification sequence of AlP and (Si).

Liang, Song-Mao; Schmid-Fetzer, Rainer

2014-11-01

198

Nucleants of Eutectic Silicon in Al-Si Hypoeutectic Alloys: ?-(Al, Fe, Si) or AlP Phase  

NASA Astrophysics Data System (ADS)

A thermodynamic description of the Al-Si-P-Fe quaternary system focused on Al-(Si)-rich alloys is developed. The solidification sequence in typical Al-7Si cast alloys is derived using thermodynamic calculations of the phase diagrams and solidification simulation under Scheil and constrained Scheil conditions. The previously claimed nucleation of eutectic silicon by ?-(Al,Fe,Si) particles is not possible because under all conditions, ?-(Al,Fe,Si) precipitates after (Si) in pertinent alloys. Variation of P in the ppm range is crucial because it changes the solidification sequence of AlP and (Si).

Liang, Song-Mao; Schmid-Fetzer, Rainer

2014-09-01

199

The Collections - Dar al-Athar al-Islamiyyah  

NSDL National Science Digital Library

Regarded by experts as one of a handful of the most comprehensive collections of Islamic art in the world, the al-Sabah holdings in Kuwait feature 20,000 objects from geographically and chronologically diverse locations. Nine categories - Metals, Ceramics, Glass, Ivory & Wood, Jewelry & Hardstone, Numismatics, Rugs & Textiles, Manuscripts & Calligraphy, and Stone & Stucco - can be accessed from the collections page with the click of a mouse. Within each category, short essays contextualize the beautiful photographs of ancient, medieval, and modern Islamic art in a wide variety of mediums and styles.

200

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

NASA Astrophysics Data System (ADS)

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.; Das, A. K.

2011-07-01

201

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

2012-09-01

202

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

203

Benefits for Military Veterans with ALS  

MedlinePLUS

... Share Print Military Veterans Resources for Military Veterans, Families & Survivors The ALS Association is working everyday to support people with ALS and their families, including our heroes who have served in the ...

204

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

205

Delsuc et al. Hexapods resurrected Hexapods Resurrected  

E-print Network

Delsuc et al. Hexapods resurrected - 1 - Hexapods Resurrected (Technical comment on: "Hexapod.1126/science.1086558 #12;Delsuc et al. Hexapods resurrected - 2 - Abstract Nardi et al. (Science, 21 March 2003, 1887) suggested that extant hexapods might be diphyletic based on the analysis of amino acids sequences

Paris-Sud XI, Université de

206

(12) United States Patent Glazer et al.  

E-print Network

. Dynamite Blvd., Phoenix, AZ (US) 85085; Michael Barrett, 9182 E. Carribean La., Scottsdale, AZ (US) 85260 2003/0131048 Al 7/2003 Najork 5,892,904 A 411999 Atkinson et aI. 2003/0158823 Al 8/2003 Fulton et al. 5

Shamos, Michael I.

207

(12) United States Patent Bezos et al.  

E-print Network

et al. 5,724,424 A 311998 Gifford 5,745,681 A 411998 Levine et al. 5,812,769 A * 911998 Graber et al by that associate. 25 Claims, 14 Drawing Sheets 120 ",,//~~ENRO;PAllS~7~s~:W~I COOKIE PROCESSING SY I IREFERRAL

Shamos, Michael I.

208

Aluminium distribution in ZSM-5 revisited: The role of Al-Al interactions  

SciTech Connect

We present a theoretical study of the distribution of Al atoms in zeolite ZSM-5 with Si/Al=47, where we focus on the role of Al-Al interactions rather than on the energetics of Al/Si substitutions at individual sites. Using interatomic potential methods, we evaluate the energies of the full set of symmetrically independent configurations of Al siting in a Si{sub 94}Al{sub 2}O{sub 192} cell. The equilibrium Al distribution is determined by the interplay of two factors: the energetics of the Al/Si substitution at an individual site, which tends to populate particular T sites (e.g., the T14 site), and the Al-Al interaction, which at this Si/Al maximises Al-Al distances in general agreement with Dempsey's rule. However, it is found that the interaction energy changes approximately as the inverse of the square of the distance between the two Al atoms, rather than the inverse of the distance expected if this were merely charge repulsion. Moreover, we find that the anisotropic nature of the framework density plays an important role in determining the magnitude of the interactions, which are not simply dependent on Al-Al distances. - Graphical abstract: Role of Al-Al interactions in high silica ZSM-5 is shown to be anisotropic in nature and not dependent solely on Coulombic interactions. Highlights: Black-Right-Pointing-Pointer Si-Al distribution in ZSM-5 is revisited, stressing the role of the Al-Al interaction. Black-Right-Pointing-Pointer Coulomb interactions are not the key factors controlling the Al siting. Black-Right-Pointing-Pointer Anisotropy of the framework is identified as a source of departure from Dempsey's rule.

Ruiz-Salvador, A. Rabdel, E-mail: rabdel@imre.oc.uh.cu [Group of Materials Developed by Design, Division of Chemistry and Technology of Materials, Institute of Materials Science and Engineering (IMRE), University of Havana, Havana 10400 (Cuba); Grau-Crespo, Ricardo; Gray, Aileen E.; Lewis, Dewi W. [Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ (United Kingdom)] [Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ (United Kingdom)

2013-02-15

209

Opportunity's 'Rub al Khali' Panorama  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Click on the image for Opportunity's 'Rub al Khali' Panorama (QTVR)

This panoramic image, dubbed 'Rub al Khali,' was acquired by NASA's Mars Exploration Rover Opportunity on the plains of Meridiani during the period from the rover's 456th to 464th sols on Mars (May 6 to May 14, 2005). Opportunity was about 2 kilometers (1.2 miles) south of 'Endurance Crater' at a place known informally as 'Purgatory Dune.'

The rover was stuck in the dune's deep fine sand for more than a month. 'Rub al Khali' (Arabic translation: 'the empty quarter') was chosen as the name for this panorama because it is the name of a similarly barren, desolate part of the Saudi Arabian desert on Earth.

The view spans 360 degrees. It consists of images obtained in 97 individual pointings of the panoramic camera. The camera took images with five camera filters at each pointing. This 22,780-by-6,000-pixel mosaic is an approximately true-color rendering generated using the images acquired through filters admitting light wavelengths of 750, 530, and 480 nanometers.

Lighting varied during the nine sols it took to acquire this panorama, resulting in some small image seams within the mosaic. These seams have been smoothed in sky parts of the mosaic to better simulate the vista that a person would see if able to view it all at the same time on Mars.

Opportunity's tracks leading back to the north (center of the panorama) are a reminder of the rover's long trek from Endurance Crater. The deep ruts dug by Opportunity's wheels as it became stuck in the sand appear in the foreground. The crest and trough of the last ripple the rover crossed before getting stuck is visible in the center. These wind-formed sand features are only about 10 to 15 centimeters (4 to 6 inches) tall. The crest of the actual ripple where the rover got stuck can be seen just to the right of center. The tracks and a few other places on and near ripple crests can be seen in this color image to be dustier than the undisturbed or 'normal' plains soils in Meridiani. Since the time these ruts were made, some of the dust there has been blown away by the wind, reaffirming the dynamic nature of the martian environment, even in this barren, ocean-like desert of sand.

2005-01-01

210

The effects of boron in TiAl/Ti/sub 3/Al  

SciTech Connect

The authors discuss the TiAl/Ti/sub 3/Al interfacial misfit dislocations structures investigated by TEM in Ti-45Al alloy and Ti-45Al/TiB/sub 2/ composite. For TiAl with c/a = 1.02, only a single set of misfit dislocation arrays are crystallographically possible; these were observed in Ti-45Al alloy. However, the observation of three sets of misfit dislocation arrays in the Ti-45Al/TiB/sub 2/ composite suggests that the occupation of octahedral sites in the TiAl structure by excess boron was responsible for a decrease in the c/a ratio leading to an increased fcc character of the TiAl at the TiAl/Ti/sub 3/Al interface.

Feng, C.R.; Michel, D.J.; Crowe, C.R. (Naval Research Lab., Washington, DC (USA). Material Science and Technology Div.)

1989-10-01

211

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

212

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

213

Accumulation of Al in Root Mucilage of an Al-Resistant and an Al-Sensitive Cultivar of Wheat.  

PubMed Central

To estimate rates of Al accumulation within the symplasm, all apoplastic pools of Al need to be eliminated or accounted for. We have developed a revised kinetic protocol that allows us to estimate the contribution of mucilage-bound Al to total, nonexchangeable Al, and to eliminate the mucilage as an apoplastic pool of Al. By comparing the Al content of excised root tips (2 cm) of wheat (Triticum aestivum L.) with and without the removal of the mucilage (using a 10-min wash in 1 M NH4Cl), we found that Al bound to the mucilage accounted for approximately 25 to 35% of Al remaining after desorption in citric acid. The kinetics of Al uptake into mucilage were biphasic, with a rapid phase occurring in the first 30 min of uptake, followed by a linear phase occurring in the remainder of the experimental period (180 min). By adopting a step for removal of mucilage into our existing kinetic protocol, we have been able to isolate a linear phase of uptake with only a slight deviation from linearity in the first 5 min. Although we cannot unambiguously identify this phase of uptake as uptake into the symplasm, we believe this new protocol provides us with the most accurate quantitative estimate of symplastic Al yet available. PMID:12226458

Archambault, D. J.; Zhang, G.; Taylor, G. J.

1996-01-01

214

Diffusion in the Ti-Al system  

SciTech Connect

Many properties of industrial Ti-Al alloys, such as high-temperature stability of the lamellar structure and creep resistance, are determined by diffusion rates in the phases and along the interfaces. The knowledge of diffusion characteristics and fundamental understanding of diffusion mechanisms are of great importance to the research and design of industrial Ti-Al alloys. This paper gives an overview of recent progress in experimental and theoretical studies of diffusion behavior in the phases of the Ti-Al system. The experimental methods used in modern diffusion measurements are briefly described, and recent experimental results for Ti and Al diffusion in {alpha}-Ti(Al), {beta}-Ti(Al), and intermetallic phases {alpha}{sub 2}-Ti{sub 3}Al and {gamma}-TiAl, are summarized. The results for interdiffusion and impurity diffusion in these phases are also discussed in detail. The second part of the paper provides an overview of current understanding of point defects and diffusion mechanisms in Ti{sub 3}Al and TiAl. A statistical model of point-defect disorder in ordered compounds is presented and applied to Ti{sub 3}Al and TiAl using input data generated with embedded-atom potentials. Possible atomic mechanisms of diffusion in these compounds are analyzed in detail, and methods of diffusion calculations under different mechanisms are reviewed. The relative importance of different mechanisms in Ti{sub 3}Al and TiAl is evaluated by comparing their estimated activation energies. Prospective topics of further experimental and theoretical research in this area are outlined.

Mishin, Y.; Herzig, C.

2000-02-09

215

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

2013-12-01

216

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

SciTech Connect

Atom probe tomography was used to characterize AlN interlayers in AlGaN/AlN/GaN heterostructures grown by plasma-assisted molecular beam epitaxy (PAMBE), NH{sub 3}-based molecular beam epitaxy (NH{sub 3}-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 NH{sub 3}-MBE and MOCVD were {approx}85% and {approx}47%, respectively. Hall measurements were performed to determine the two-dimensional electron gas mobility and sheet concentration. Sheet concentrations were {approx}25%-45% higher with molecular beam epitaxy than with MOCVD, and these results matched well with atom probe data.

Mazumder, Baishakhi; Kaun, Stephen W.; Speck, James S. [Materials Department, University of California, Santa Barbara, California 93106 (United States)] [Materials Department, University of California, Santa Barbara, California 93106 (United States); Lu, Jing; Keller, Stacia; Mishra, Umesh K. [Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)] [Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)

2013-03-18

217

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

218

Oxidation resistance of intermetallic compounds Al 3 Ti and TiAl  

Microsoft Academic Search

The oxidation kinetics and morphological features of Al3Ti and TiAl were investigated. The oxidation resistance of Al3Ti is much better than that of TiAl, for example, by a factor of about 30 at 1000° C for 48 h. The big difference in the oxidation resistance is related to the characteristics of the external oxide scales of a protective Al2O3 or

Y. Umakoshi; M. Yamaguchi; T. Sakagami; T. Yamane

1989-01-01

219

Abrasive wear behavior of NiAl and NiAl–TiB 2 composites  

Microsoft Academic Search

Abrasive wear of NiAl and NiAl with 10, 20, and 40 vol.% TiB2 has been investigated using particles of different types and sizes. The addition of TiB2 as a particulate reinforcement to NiAl increases the hardness of the composite with respect to NiAl, and reduces the wear rate at all volume fractions on garnet and Al2O3 abrasives. Abrasion on SiC

Jeffrey A. Hawk; David E. Alman

1999-01-01

220

Toxicity of Al to Desulfovibrio desulfuricans  

SciTech Connect

The toxicity of Al to Desulfovibrio desulfuricans G20 was assessed over a period of eight weeks in a modified lactate-C medium buffered at four initial pHs (5.0, 6.5, 7.2, and 8.3) and treated with five levels of added Al (none, 0.01, 0.1, 1.0, and 10 mM). At pH 5, cell populations decreased significantly and any effect of Al was negligible compared to that of pH. At higher pH, no direct impact of Al was seen at concentrations of soluble Al below 5x10-5 M. Soluble Al concentrations exceeded this level in the pH-6.5 and pH-7.2 treatments having total-Al concentrations= 1 mM and caused substantial and proportional decreases in cell populations. In contrast to the small size and vibrio morphology seen in most treatments, substantial numbers of large spirilloidal bacteria were seen in the pH-8.3 treatments, and their incidence was correlated with greater total-Al concentrations. This effect was believed to be a result of Mg deprivation stemming from adsorption/coprecipitation of Mg with Al hydroxy-sulfate gels rather than a direct response to high total-Al levels. Calculations of soluble-Al speciation suggested the presence of the Al13O4(OH)24(H2O)127+''tridecamer'' cation in the pH-6.5 and pH-7.2 treatments showing direct Al toxicity. Analysis of inoculated and control samples from the pH-6.5 and pH-8.3 10-mM Al treatments by 27Al nuclear-magnetic-resonance spectroscopy yielded broad 4800-Hz resonances at 58 ppm, near the 63-ppm resonance expected for the tridecamer cation. These resonances were independent of sample filtration through 25,000 MWCO membranes and attributed to self-assembled colloidal clusters of hydrophobic tridecamer species that had been neutralized by sorption of lactate and sulfate anions. Although indirect effects of Al addition were believed to have caused the lower cell populations observed in the pH-8.3 treatments, the NMR data suggest that direct effects of Al toxicity stemming from tridecamer colloids cannot be excluded.

Amonette, James E.; Russell, Colleen K.; Carosino, Katie A.; Robinson, Nicole L.; Ho, Jennifer T.

2003-07-02

221

New Al–Mg–Sc alloys  

Microsoft Academic Search

Data on new 01515, 01523, 01535, 01545, 01570 and 01571 wrought weldable alloys based on the Al–Mg–Sc system are presented. These alloys differ from each other, mainly, by magnesium content and belong to the family of non-heat-treatable alloys. Wrought Al–Mg–Sc alloy semiproducts as-hot worked or as-annealed show much higher properties (especially yield strength) than those made from conventional Al–Mg alloys

Yu. A Filatov; V. I Yelagin; V. V Zakharov

2000-01-01

222

Al Pie De La Letra  

PubMed Central

Background and Purpose Ethnic minorities are at higher stroke risk than non-Hispanic whites yet are less likely to have optimal vascular risk factor control. There is a need to develop culturally sensitive strategies for enhancing vascular risk reduction in minority patients with stroke. This study aimed to develop a postdischarge report card to boost treatment adherence among elderly Spanish-speaking patients with stroke within an urban health system. Methods This study included a total of 13 Spanish-only speaking participants aged ?60 years discharged from a local government hospital in Los Angeles within 18 months of an index ischemic stroke and 6 caregivers engaged in focus groups and interviews. Structured interviews were conducted with 11 care providers and 9 administrators at the hospital. Framework analysis examined the data and elicited themes to adapt a pre-existing patient report card tool. Results Spontaneously using the same phrase, “Al pie de la letra,” several participants expressed a need to follow medical instructions accurately to prevent recurrent stroke and identified barriers/facilitators for doing so. They made comments about the pre-existing report card, advising several changes, including the clarification of phrases, and written instructions to explain the need for the card and how to fill it out. The providers and administrators recommended avenues for successfully using the card at the hospital. A new report card was created that incorporated all major perspectives. Conclusions Crafting a culturally sensitive tool for promoting treatment adherence in elderly Spanish-only-speaking patients with stroke within an urban health system using a participatory methodology is feasible. The efficacy of this new report card should be tested in a randomized controlled trial. PMID:20167904

Ovbiagele, Bruce

2014-01-01

223

Internal Detoxification Mechanism of Al in Hydrangea (Identification of Al Form in the Leaves).  

PubMed Central

An internal detoxification mechanism for Al was investigated in an Al-accumulating plant, hydrangea (Hydrangea macrophylla), focusing on Al forms present in the cells. The leaves of hydrangea contained as much as 15.7 mmol Al kg-1 fresh weight, and more than two-thirds of the Al was found in the cell sap. Using 27Al- nuclear magnetic resonance, the dominant peak of Al was observed at a chemical shift of 11 to 12 parts per million in both intact leaves and the extracted cell sap, which is in good accordance with the chemical shift for the 1:1 Al-citrate complex. Purification of cell sap by molecular sieve chromatography (Sephadex G-10) combined with ion-exclusion chromatography indicated that Al in fractions with the same retention time as citric acid contributed to the observed 27Al peak in the intact leaves. The molar ratio of Al to citric acid in the crude and purified cell sap approximated 1. The structure of the ligand chelated with Al was identified to be citric acid. Bioassay experiments showed that the purified Al complex from the cell sap did not inhibit root elongation of corn (Zea mays L.) and the viability of cells on the root tip surface was also not affected. These observations indicate that Al is bound to citric acid in the cells of hydrangea leaves. PMID:12223659

Ma, J. F.; Hiradate, S.; Nomoto, K.; Iwashita, T.; Matsumoto, H.

1997-01-01

224

Exercise does not Increase ALS Risk  

MedlinePLUS

... for potentially confounding variables, such as the degree athletes who developed ALS used legal or illegal medications, took dietary supplements, and were exposed to pesticides or other toxins ...

225

Interfacial Phenomena in Al/Al, Al/Cu, and Cu/Cu Joints Soldered Using an Al-Zn Alloy with Ag or Cu Additions  

NASA Astrophysics Data System (ADS)

The studies of soldered joints were carried out in systems: Al/solder/Al, Al/solder/Cu, Cu/solder/Cu, where the solder was (Al-Zn)EUT, (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Ag and (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Cu addition. Brazing was performed at 500 °C for 3 min. The EDS analysis indicated that the composition of the layers starting from the Cu pad was CuZn, Cu5Zn8, and CuZn4, respectively. Wetting tests were performed at 500 °C for 3, 8, 15, and 30 min, respectively. Thickness of the layers and their kinetics of growth were measured based on the SEM micrographs. The formation of interlayers was not observed from the side of Al pads. On the contrary, dissolution of the Al substrate and migration of Al-rich particles into the bulk of the solder were observed.

Pstru?, Janusz; Gancarz, Tomasz

2014-05-01

226

[Management and care for patients with ALS].  

PubMed

For the past decade or so, the research in ALS has dramatically changed, coinciding with the discovery of SOD1 mutations, the generation of SOD1 transgenic rodents, and the introduction of riluzole. The ALS practice guidelines have been published in a number of countries, whereas the National Database has shown the actual reality of patient practice in ALS. Multidisciplinary ALS Clinics, consisting of a team of health care professionals, provide highly specialized quality care for patients and families, and have become the standard of care in many countries. A number of mostly retrospective studies report that non-invasive positive pressure ventilation prolongs survival and improves the quality of life and other functions. Enteral feeding certainly improves quality of life, but it is still uncertain if it prolongs survival. Although end of life issues in ALS care have been difficult more and more ALS clinicians are paying serious attention to it. Clinical trials are imperative to find effective medications for ALS, and many different pharmacological agents, based on a number of different hypotheses in ALS, are being actively tested or are about to be tested in the near future. Undoubtedly, we are in the midst of incredible progress in ALS. PMID:17432192

Mitsumoto, Hiroshi; Howe, Wesley J

2006-11-01

227

?-Phase Formation in Ni-Al Systems  

NASA Astrophysics Data System (ADS)

First-principles full-potential linear muffin-tin orbital method (FPLMTO) were performed for ?-type structural phase transformation for B2 (b.c.c.) NiAl and Ni_2Al alloys. In contrast to the NiAl system but in agreement with experiments, the results of our calculation showed that the Ni_2Al system is unstable with respect to this kind of transformation. To better understand the origin of stability and instability in each system, we also used a pair potential for modeling the interactions between the atoms. Calculated lattice parameters for the structures are in excellent agreement with the experimental data.

Albers, R. C.; Sanati, M.; Pinski, F. J.

1998-03-01

228

Anodic Behavior of Al and the Alloys Al-In and Al-In-Ga in Aluminum-Air Batteries.  

National Technical Information Service (NTIS)

By recording of the polarization characteristics and measurement of the currents of self-dissolution, 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 con...

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

1979-01-01

229

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

230

Investigation of TiAl\\/Ti 2AlC composites prepared by spark plasma sintering  

Microsoft Academic Search

TiAl\\/Ti2AlC composites were produced by spark plasma sintering technology from mixed powders of Ti, Al and TiC. X-ray diffraction (XRD) patterns showed that the sintered products mainly consisted of TiAl and Ti2AlC phases. Electric probe microcosmic analysis (EPMA) photos indicated different microstructures depending on composition. In one case, when 7vol.%TiC was mixed in the starting powders, the produced Ti2AlC particles

Bingchu Mei; Yoshinari Miyamoto

2002-01-01

231

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

232

United States Patent [19] Miura et al.  

E-print Network

such as boron neutron capture therapy and photodynamic therapy. 3 Therapy for Cancer, Kobe, Japan (Oct. 31--Nov. 4, 1994). Miura et al., "Synthesis and Spectroscopic Capture Therapy", Tetrahedron Letters, 31(16), pp. 2247--2250 (1990). Chiusoli et al., "Synthesis

Shelnutt, John A.

233

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

234

Everyday Life with ALS: A Practical Guide  

MedlinePLUS

... MDA. Flu shots can help protect the respiratory system. Online support MDA’s ALS Division offers news and a series of regularly scheduled online chats, plus occasional conferences with ALS specialists and experts. Transcripts of past chats are posted. MDA also ...

235

United States Patent [19] Church et al.  

E-print Network

United States Patent [19] Church et al. [54] CHARACTERIZATION OF INDIVIDUAL POLYMER MOLECULES BASED al.. "Effect of Point Mutations on the in-Vitro Pore Properties ofMaltoporin. a Protein physical changes across an interface between two pools of media as the linear polymer traverses

Church, George M.

236

Quantitatively probing the Al distribution in zeolites.  

PubMed

The degree of substitution of Si(4+) by Al(3+) in the oxygen-terminated tetrahedra (Al T-sites) of zeolites determines the concentration of ion-exchange and Brønsted acid sites. Because the location of the tetrahedra and the associated subtle variations in bond angles influence the acid strength, quantitative information about Al T-sites in the framework is critical to rationalize catalytic properties and to design new catalysts. A quantitative analysis is reported that uses a combination of extended X-ray absorption fine structure (EXAFS) analysis and (27)Al MAS NMR spectroscopy supported by DFT-based molecular dynamics simulations. To discriminate individual Al atoms, sets of ab initio EXAFS spectra for various T-sites are generated from DFT-based molecular dynamics simulations, allowing quantitative treatment of the EXAFS single- and multiple-photoelectron scattering processes out to 3-4 atom shells surrounding the Al absorption center. It is observed that identical zeolite types show dramatically different Al distributions. A preference of Al for T-sites that are part of one or more 4-member rings in the framework over those T-sites that are part of only 5- and 6-member rings in an HBEA150 zeolite has been determined using this analysis. PMID:24815517

Vjunov, Aleksei; Fulton, John L; Huthwelker, Thomas; Pin, Sonia; Mei, Donghai; Schenter, Gregory K; Govind, Niranjan; Camaioni, Donald M; Hu, Jian Zhi; Lercher, Johannes A

2014-06-11

237

[Electrodiagnosis of ALS: its practical aspects].  

PubMed

Electrodiagnostic methods, especially needle EMG plays an important role for the ALS diagnosis. Existing diagnostic criteria such as revised El Escorial criteria (R-EEC) and Awaji algorithm have a drawback of low sensitivity. Our study revealed that the percentage of patients classified as confirmed ALS, i.e. clinically probable (laboratory supported) or higher, was 43% using the R-EEC and 37% using the Awaji algorithm. Needle EMG can strongly suggest ALS beyond these criteria. Fasciculation potentials (FPs) are sufficiently specific for ALS, and we have argued its diagnostic utitlity in ALS diagnosis. FPs are rare in other neurogenic diseases, such as cervical or lumbar spine disorders and spinal and bulbar muscular atrophy. Profuse FPs observed in both upper and lower limbs would strongly suggest ALS. EMG of the upper trapezius muscle is useful since it is easily relaxed, and the spontaneous activities in this muscle are sufficiently sensitive and specific for ALS. Inclusion body myositis (IBM) might be confused with ALS, but its differentiation is actually easy since a normal recruitment in a chronically weak muscle definitely indicates myopathy. Furthermore, EMG of the flexor digitorum profundus muscle in IBM patients would reveal typical myopathic, i.e. low-amplitude and thin, motor unit potentials. PMID:22277500

Sonoo, Masahiro; Higashihara, Mana; Hokkoku, Keiichi

2011-11-01

238

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

239

NiAl alloys for structural uses  

NASA Technical Reports Server (NTRS)

Alloys based on the intermetallic compound NiAl are of technological interest as high temperature structural alloys. These alloys possess a relatively low density, high melting temperature, good thermal conductivity, and (usually) good oxidation resistance. However, NiAl and NiAl-base alloys suffer from poor fracture resistance at low temperatures as well as inadequate creep strength at elevated temperatures. This research program explored macroalloying additions to NiAl-base alloys in order to identify possible alloying and processing routes which promote both low temperature fracture toughness and high temperature strength. Initial results from the study examined the additions of Fe, Co, and Hf on the microstructure, deformation, and fracture resistance of NiAl-based alloys. Of significance were the observations that the presence of the gamma-prime phase, based on Ni3Al, could enhance the fracture resistance if the gamma-prime were present as a continuous grain boundary film or 'necklace'; and the Ni-35Al-20Fe alloy was ductile in ribbon form despite a microstructure consisting solely of the B2 beta phase based on NiAl. The ductility inherent in the Ni-35Al-20Fe alloy was explored further in subsequent studies. Those results confirm the presence of ductility in the Ni-35Al-20Fe alloy after rapid cooling from 750 - 1000 C. However exposure at 550 C caused embrittlement; this was associated with an age-hardening reaction caused by the formation of Fe-rich precipitates. In contrast, to the Ni-35Al-20Fe alloy, exploratory research indicated that compositions in the range of Ni-35Al-12Fe retain the ordered B2 structure of NiAl, are ductile, and do not age-harden or embrittle after thermal exposure. Thus, our recent efforts have focused on the behavior of the Ni-35Al-12Fe alloy. A second parallel effort initiated in this program was to use an alternate processing technique, mechanical alloying, to improve the properties of NiAl-alloys. Mechanical alloying in the conventional sense requires ductile powder particles which, through a cold welding and fracture process, can be dispersion strengthened by submicron-sized oxide particles. Using both the Ni-35Al-Fe alloys to contain approx. 1 v/o Y2O3. Preliminary results indicate that mechanically alloyed and extruded NiAl-Fe + Y2O3 alloys when heat treated to a grain-coarsened condition, exhibit improved creep resistance at 1000 C when compared to NiAl; oxidation resistance comparable to NiAl; and fracture toughness values a factor of three better than NiAl. As a result of the research initiated on this NASA program, a subsequent project with support from Inco Alloys International is underway.

Koss, D. A.

1991-01-01

240

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

2013-10-01

241

AL(0) in municipal waste incinerator ash  

NASA Astrophysics Data System (ADS)

Disposal of municipal waste is a challenge to society. Waste volume is substantially decreased by incineration but residual ash usually contains a number of toxic components which must be immobilised to insure environmental protection. One element, chromium, is mobile and toxic in its oxidised state as Cr(VI) but it can be reduced to Cr(III) and immobilised. Reduction can be promoted by ash treatment with Fe(0) or Fe(II), but recent evidence shows that at least some Cr(VI) is reduced spontaneously in the ash. Aspects of ash behaviour suggest metallic aluminium as the reducing agent, but no direct evidence of Al(0) has been found until now. We examined filter ash from an energy-producing, municipal-waste incinerator (Vest-forbrænding) near Copenhagen. X-ray diffraction (XRD) identified expected salts of Na, K and Ca such as halite, sylvite, calcite, anhydrite and gypsum as well as quartz, feldspar and some hematite. Wave-dispersive electron microprobe produced elemen-tal maps of the ash; Al-rich areas were analysed quantitatively by comparison with standards. We identified metallic Al particles, averaging 50 to 100 micrometers in di-ameter, often with a fractured, glassy border of aluminum oxide. The particles were porous, explaining fast Cr(VI) reduction and they contained thin exsolution lamellae of Al-alloys of Pb and Cu or Mn, Fe and Ag, which provide clues of the Al(0) origin in the waste. Sometimes Al(0) occurred inside glassy globes of Al2O3. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) proved that surface Al concentrations on ash particles were below detection, confirming reactivity of the Al(0) bulk. The persistence of reduced Al through the highly oxidising combustion procedure comes as a surprise and is a benefit in the immobilisation of Cr(VI) from municipal-waste incineration residues.

Stipp, S. L.; Ronsbo, J. G.; Zunic, T. B.; Christensen, T. H.

2003-04-01

242

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

243

Infrared brazing of TiAl using Al-based braze alloys  

Microsoft Academic Search

A novel approach for joining TiAl by infrared vacuum brazing using pure aluminum and BAlSi-4 filler metal has been reported in the study. For pure Al filler metal, the extensive presence of stable TiAl3 phase in the joint results in inherent brittleness of the bond, and it is difficult to completely remove the stable TiAl3 by heat treatment after infrared

R. K. Shiue; S. K. Wu; S. Y. Chen

2003-01-01

244

Tree fine root Ca\\/Al molar ratio – Indicator of Al and acidity stress  

Microsoft Academic Search

High soil acidity and elevated soil Al concentrations limit plant growth in many terrestrial ecosystems. Aluminium toxicity can be ameliorated by Ca. Thus, Ca\\/Al molar ratios in soil solution and in plant tissues have been proposed as superior indicators than Al concentration itself for evaluating the Al toxicity stress to trees (Cronan & Grigal, J Environ Qual 1995;24:209 – 226). This article

E. I. Vanguelova; Y. Hirano; T. D. Eldhuset; L. Sas-Paszt; M. R. Bakker; Ü. Püttsepp; I. Brunner; K. Lõhmus; D. Godbold

2007-01-01

245

Linewidth and underlayer influence on texture in submicrometer-wide Al and AlCu lines  

Microsoft Academic Search

The local texture in three types of patterned, thin-film, Al and AlCu interconnections on Si semiconductor devices is investigated by electron backscatter diffraction. Two types of standard planar metal structures were investigated: (1) blanket Al and (2) blanket Al-0.5 wt % Cu on TiN\\/Ti underlayers. Both were deposited on amorphous SiO2 substrates followed by reactive ion etching to define 0.45-10

J. L. Hurd; K. P. Rodbell; L. M. Gignac; L. A. Clevenger; R. C. Iggulden; R. F. Schnabel; S. J. Weber; N. H. Schmidt

1998-01-01

246

Linewidth and underlayer influence on texture in submicrometer-wide Al and AlCu lines  

Microsoft Academic Search

The local texture in three types of patterned, thin-film, Al and AlCu interconnections on Si semiconductor devices is investigated by electron backscatter diffraction. Two types of standard planar metal structures were investigated: (1) blanket Al and (2) blanket Al–0.5 wt % Cu on TiN\\/Ti underlayers. Both were deposited on amorphous SiO2 substrates followed by reactive ion etching to define 0.45–10

J. L. Hurd; K. P. Rodbell; L. M. Gignac; L. A. Clevenger; R. C. Iggulden; R. F. Schnabel; S. J. Weber; N. H. Schmidt

1998-01-01

247

The site occupancies of alloying elements in TiAl and Ti 3Al alloys  

Microsoft Academic Search

The site occupancies of V, Cr, Mn, Fe, Ni, Zr, Nb, Mo, Ta, Ga and Sn (1–5at.%) in TiAl alloys with different compositions, and in Ti3Al with the compositions of Ti–26at.%Al–(1–2at.%)X, were measured by the atom location channelling enhanced microanalysis (ALCHEMI) method. For TiAl alloys, the results show that Zr, Nb and Ta atoms invariably occupy Ti sites, while Fe,

Y. L. Hao; D. S. Xu; Y. Y. Cui; R. Yang; D. Li

1999-01-01

248

Corrosion Studies of 2195 Al-Li Alloy and 2219 Al Alloy with Differing Surface Treatments  

NASA Technical Reports Server (NTRS)

Corrosion studies of 2195 Al-Li and 2219 Al alloys have been conducted using the scanning reference electrode technique (SRET) and the polarization resistance (PR) technique. The SRET was used to study corrosion mechanisms, while corrosion rate measurements were studied with the PR technique. Plates of Al203 blasted, soda blasted and conversion coated 2219 Al were coated with Deft primer and the corrosion rates studied with the EIS technique. Results from all of these studies are presented.

Danford, M. D.; Mendrek, M. J.

1998-01-01

249

27Al-NQR\\/NMR Study of Kondo Semiconductor CeFe2Al10  

Microsoft Academic Search

27Al-NQR\\/NMR measurements have been performed on CeFe2Al10 in relevance to the novel phase below T0=27 K of isostructural CeRu2Al10. NQR peaks are assigned to five crystallographically inequivalent Al sites. No splitting of the NQR spectra down to 1.5 K confirms the lack of phase transition in this compound. The gaplike decrease in the spin-lattice relaxation rate 1\\/T1 above about 20

Yukihiro Kawamura; Shingo Edamoto; Tomoaki Takesaka; Takashi Nishioka; Harukazu Kato; Masahiro Matsumura; Yo Tokunaga; Shinsaku Kambe; Hiroshi Yasuoka

2010-01-01

250

A Revision of the Al-rich Region of the Sm-Al Phase Diagram: The Sm 3 Al 11 Phase  

Microsoft Academic Search

Phase equilibria in the Al-rich region of the Sm-Al binary system has been revised and updated: it has been confirmed that\\u000a Sm3Al11 is a congruently melting phase which, on cooling, undergoes catatectic decomposition Sm3Al11 ? liquid + SmAl3.

S. Delsante; R. Raggio; G. Borzone; R. Ferro

2007-01-01

251

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

252

Evaluating Zn, Al and Al-Zn coatings on carbon steel in a special atmosphere  

SciTech Connect

This paper presents a comparative evaluation of Al, Zn and Al-Zn coatings on carbon steel exposed to a coastal-marine atmosphere. It is a very aggressive atmosphere with high wind velocities (corrosion-erosion rate = 1.4 mm/year for ASTM 1029 steel). A metallized zinc coating with a pore sealer was also evaluated. ISO and ASTM standards were used for the evaluation. After a two-year exposure the best performance was achieved by the Al and Al rich alloy (85%Al-15%Zn) with some damage of the coatings. But the Zn metallized coating, with a pore sealer, did not show signs of damage.

Troconis de Rincon, O.; Delgado, R.; Lopez, B. [Univ. del Zulia, Maracaibo (Venezuela). Centro de Estudios de Corrosion; Uruchutu, J. [Univ. de Cuernavaca (Mexico)

1999-11-01

253

Atomistic Modeling of RuAl and (RuNi) Al Alloys  

NASA Technical Reports Server (NTRS)

Atomistic modeling of RuAl and RuAlNi alloys, using the BFS (Bozzolo-Ferrante-Smith) method for alloys is performed. The lattice parameter and energy of formation of B2 RuAl as a function of stoichiometry and the lattice parameter of (Ru(sub 50-x)Ni(sub x)Al(sub 50)) alloys as a function of Ni concentration are computed. BFS based Monte Carlo simulations indicate that compositions close to Ru25Ni25Al50 are single phase with no obvious evidence of a miscibility gap and separation of the individual B2 phases.

Gargano, Pablo; Mosca, Hugo; Bozzolo, Guillermo; Noebe, Ronald D.; Gray, Hugh R. (Technical Monitor)

2002-01-01

254

Reassessment of NiAl and Ni-Fe-Al solidus temperatures  

Microsoft Academic Search

Solidus temperatures of the B2 NiAl phase have been determined by high-temperature differential thermal analysis for binary\\u000a melt compositions NixAl100?x\\u000a (45xyNi50?yAl50 (0?y?50). It was shown that the melting temperature of the stoichiometric Ni50Al50 phase is 1681 °C, which is 43 K higher than some literature data. The solidus line at the Ni-rich side of the Ni-Al phase\\u000a diagram exhibits a

H. Bitterlich; W. Löser; L. Schultz

2002-01-01

255

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

256

Reaction of Ti and Ti-Al alloys with alumina  

NASA Technical Reports Server (NTRS)

The reaction of single-crystal Al2O3 with pure Ti and Ti-Al alloys with different Al concentrations was examined in the temperature range of 1173 to 1573 K. Significant reaction occurred between Al2O3 and the Ti-Al alloys with Al concentrations lower than that corresponding to the gamma-TiAl phase. The reaction mechanism was determined to be simultaneous diffusion of Al and atomic oxygen from Al2O3 into Ti and the Ti-Al alloys.

Misra, Ajay K.

1991-01-01

257

Thermal diffusion in Ni/Al multilayer  

SciTech Connect

Two Ni/Al multilayers deposited by ion beam sputtering of nominal design [Ni(200A)/Al(100A)] Multiplication-Sign 5 and [Ni(50A)/Al(227A)] Multiplication-Sign 5 on Si substrates were annealed at 200 Degree-Sign 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.; Basu, S. [Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Gupta, M. [UGC-DAE-Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India)

2013-02-05

258

[A strategy to develop effective ALS therapy].  

PubMed

In the early 1990s, a number of major events took place in the history of the treatment and science of ALS. A cause of familial ALS, the mutation of superoxide dismutase 1, was discovered and very shortly after, an animal model expressing the human SOD1 mutation for familial ALS was generated. Around the same time, the first medication for the treatment of ALS, riluzole, was approved. Clinical neurologists started to focus more attention on quality of life and standardizing care for patients with ALS, including devising approaches for presenting and discussing the diagnosis, using aggressive symptomatic treatments, and developing a multidisciplinary care system. Since then, nutritional and respiratory care has markedly improved. Respiratory care for those with terminal ALS in Japan has been distinct and perhaps more effective compared to the rest of the world, and this unique experience must be broadly published and shared with others. In 1999, the ALS Treatment Guidelines were published by the American Academy of Neurology and are now under revision. A monitoring system to determine the impact the Guidelines had on actual patient care has taught us that caregivers have only slowly accepted the recommendation to improve quality of care. The team approach, using a multidisciplinary care system from diagnosis to the end of life, is essential to improve care for both the patient and family. Coinciding with the progress in ALS treatment, basic science and translational research also produced dramatic progress in ALS drug discovery. Over the past 15 years, more than 25 potential drugs have been tested in randomized controlled trials. Despite this progress, we have no medications other than riluzole. Although it may be true that ALS research is in its early stages compared to research in other diseases with no cure--it is probably behind cancer research by at least 20 or 30 years--we need to drastically change our approach to drug development. At a national level, we need to create a strong, cohesive team with support from a number of funding agencies, oversight from a regulatory agency, and investigators who all think "outside the box." In addition, we should obtain ideas and suggestions from accomplished experts outside of the field of ALS and put competition aside as we work together to develop strategic plans for the ALS drug development that is essential to beat this devastating disease. PMID:17447525

Mitsumoto, Hiroshi

2007-04-01

259

Wetting of polycrystalline SiC by molten Al and Al-Si alloys  

NASA Astrophysics Data System (ADS)

The wetting of ?-SiC by molten Al and Al-Si alloys was investigated using a dispensed sessile drop method in a high vacuum. In the Al-SiC system, representative wetting stages were identified. The liquid spreading was initially controlled by the deoxidation of the SiC surface and then by the formation of Al4C3 at the interface. The intrinsic contact angle for molten Al on the polycrystalline ?-SiC surface was suggested to be lower than 90? provided that the oxide films covering the Al and SiC surfaces were removed, i.e., the system is partial wetting in nature. An increase in the Si concentration in liquid Al weakened the interfacial reaction but improved the final wettability. The role of the Si addition on the wetting was presumably attributed to its segregation at the interface and the formation of strong chemical bonds with the SiC surface.

Cong, Xiao-Shuang; Shen, Ping; Wang, Yi; Jiang, Qichuan

2014-10-01

260

High quality AlGaN grown on ELO AlN/sapphire templates  

NASA Astrophysics Data System (ADS)

The defect structure and the homogeneity of 1-3 µm thick AlxGa1-xN layers grown on epitaxially laterally overgrown (ELO) AlN on patterned AlN/sapphire templates have been investigated in dependence on the miscut direction of the c-plane sapphire substrates, the etching depth into the sapphire and the Al concentration. It was found that shallowly etched AlN/sapphire templates with a 0.25° miscut toward the a-plane provide a smooth surface of ELO AlN and therefore a good Al homogeneity in the overgrown Al0.8Ga0.2N layer. The threading dislocation density in these layers is as low as 5×108 cm-2.

Zeimer, U.; Kueller, V.; Knauer, A.; Mogilatenko, A.; Weyers, M.; Kneissl, M.

2013-08-01

261

Calcium platinum aluminium, CaPtAl  

PubMed Central

A preliminary X-ray study of CaPtAl has been reported previously by Hulliger [J. Alloys Compd (1993), 196, 225–228] based on X-ray powder diffraction data without structure refinement. With the present single-crystal X-ray study, we confirm the assignment of the TiNiSi type for CaPtAl, in a fully ordered inverse structure. All three atoms of the asymmetric unit have .m. site symmetry. The structure features a ? 3[AlPt] open framework with a fourfold coordination of Pt by Al atoms and vice versa. The Ca atoms are located in the large channels of the structure. PMID:22064850

Kenfack Tsobnang, Patrice; Fotio, Daniel; Ponou, Simeon; Fon Abi, Charles

2011-01-01

262

Nominalization in Q'anjob'al (Maya)  

E-print Network

Q’anjob’al typically makes a rigid distinction between transitive and intransitive verb inflections. Transitive verbs cross-reference their subjects with an ergative prefix while intransitive verbs cross-reference their ...

Mateo, Pedro

2010-01-01

263

COMMUNICATION MatthiasTreier et al.  

E-print Network

COMMUNICATION MatthiasTreier et al. Anaromaticcouplingmotiffor two-dimensionalsupramolecular architectures ISSN1359-7345 www.rsc.org/chemcomm Number38|14October2008|Pages4509­4648 Chemical Communications

Hone, James

264

12th Annual ALS Users' Association Meeting  

SciTech Connect

Science took the front seat as 219 Advanced Light Source (ALS) users and staff gathered on Monday and Tuesday, October 18 and 19 for the twelfth annual users' meeting. The bulk of the meeting was dedicated to reports on science at the ALS. Packed into two busy days were 31 invited oral presentations and 80 submitted poster presentations, as well as time to visit 24 vendor booths. The oral sessions were dedicated to environmental science, chemical dynamics, biosciences, magnetic materials, and atomic and molecular science. In addition, there was an ALS highlights session that emphasized new results and a session comprising highlights from the young scientists who will carry the ALS into the future.

Robinson, Arthur L.

1999-12-17

265

Analysis of al-2 Mutations in Neurospora  

PubMed Central

The orange pigmentation of the fungus Neurospora crassa is due to the accumulation of the xanthophyll neurosporaxanthin and precursor carotenoids. Two key reactions in the synthesis of these pigments, the formation of phytoene from geranylgeranyl pyrophosphate and the introduction of ? cycles in desaturated carotenoid products, are catalyzed by two domains of a bifunctional protein, encoded by the gene al-2. We have determined the sequence of nine al-2 mutant alleles and analyzed the carotenoid content in the corresponding strains. One of the mutants is reddish and it is mutated in the cyclase domain of the protein, and the remaining eight mutants are albino and harbor different mutations on the phytoene synthase (PS) domain. Some of the mutations are expected to produce truncated polypeptides. A strain lacking most of the PS domain contained trace amounts of a carotenoid-like pigment, tentatively identified as the squalene desaturation product diapolycopene. In support, trace amounts of this compound were also found in a knock-out mutant for gene al-2, but not in that for gene al-1, coding for the carotene desaturase. The cyclase activity of the AL-2 enzyme from two albino mutants was investigated by heterologous expression in an appropriately engineered E. coli strain. One of the AL-2 enzymes, predictably with only 20% of the PS domain, showed full cyclase activity, suggesting functional independence of both domains. However, the second mutant showed no cyclase activity, indicating that some alterations in the phytoene synthase segment affect the cyclase domain. Expression experiments showed a diminished photoinduction of al-2 transcripts in the al-2 mutants compared to the wild type strain, suggesting a synergic effect between reduced expression and impaired enzymatic activities in the generation of their albino phenotypes. PMID:21818281

Diaz-Sanchez, Violeta; Estrada, Alejandro F.; Trautmann, Danika; Limon, M. Carmen; Al-Babili, Salim; Avalos, Javier

2011-01-01

266

Analysis of al-2 mutations in Neurospora.  

PubMed

The orange pigmentation of the fungus Neurospora crassa is due to the accumulation of the xanthophyll neurosporaxanthin and precursor carotenoids. Two key reactions in the synthesis of these pigments, the formation of phytoene from geranylgeranyl pyrophosphate and the introduction of ? cycles in desaturated carotenoid products, are catalyzed by two domains of a bifunctional protein, encoded by the gene al-2. We have determined the sequence of nine al-2 mutant alleles and analyzed the carotenoid content in the corresponding strains. One of the mutants is reddish and it is mutated in the cyclase domain of the protein, and the remaining eight mutants are albino and harbor different mutations on the phytoene synthase (PS) domain. Some of the mutations are expected to produce truncated polypeptides. A strain lacking most of the PS domain contained trace amounts of a carotenoid-like pigment, tentatively identified as the squalene desaturation product diapolycopene. In support, trace amounts of this compound were also found in a knock-out mutant for gene al-2, but not in that for gene al-1, coding for the carotene desaturase. The cyclase activity of the AL-2 enzyme from two albino mutants was investigated by heterologous expression in an appropriately engineered E. coli strain. One of the AL-2 enzymes, predictably with only 20% of the PS domain, showed full cyclase activity, suggesting functional independence of both domains. However, the second mutant showed no cyclase activity, indicating that some alterations in the phytoene synthase segment affect the cyclase domain. Expression experiments showed a diminished photoinduction of al-2 transcripts in the al-2 mutants compared to the wild type strain, suggesting a synergic effect between reduced expression and impaired enzymatic activities in the generation of their albino phenotypes. PMID:21818281

Díaz-Sánchez, Violeta; Estrada, Alejandro F; Trautmann, Danika; Limón, M Carmen; Al-Babili, Salim; Avalos, Javier

2011-01-01

267

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

268

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

269

Air blast characteristics of laminated al and NI-AL casings  

NASA Astrophysics Data System (ADS)

Air blast characteristics of Al and Ni-Al laminated materials were experimentally investigated in a 23 m3 closed chamber. Ni and Al foils, 50 to 100 micrometers in thickness, were rolled and compacted to form a cylindrical casing with a density of 95% TMD through an explosive formation technique. Charges were prepared using 2 kg C4 explosive packed in the laminated casing to a metal-explosive mass ratio of 1.75. The blast pressure history measured on the chamber wall showed a double-shock front structure with a precursor shock followed by the primary blast. The front peak pressure for the Ni-Al cased charge reaches 1.5-2 times that of the Al cased, consistent with the larger fireball recorded for the Ni-Al cased. The long time quasi-static explosion pressure (QSP) from the Ni- Al cased charge is 0.8 of that of the Al cased, due to half of Al mass in the Ni-Al.

Zhang, Fan; Ripley, Robert; Wilson, William

2012-03-01

270

Formation and large cryogenic magnetocaloric effect of HoAl2/Al2O3 nanocapsules  

NASA Astrophysics Data System (ADS)

HoAl2/Al2O3 nanocapsules with a core of HoAl2 and a shell of amorphous Al2O3 have been synthesized. The formation of the rare-earth compound nanocapsules can be ascribed to the different melting points and the optimal proportions of Ho and Al atoms during the arc-discharging process. Furthermore, the formation of the Al2O3 shell protects the rare-earth atoms from serious oxidation. The HoAl2/Al2O3 nanocapsules display superparamagnetic properties between the blocking temperature of 6 K and the Curie temperature of 26 K. The absolute value of the magnetic-entropy change in the HoAl2/Al2O3 nanocapsules rapidly increases with the decrease in temperature and reaches 14.7 J kg-1 K-1 at 3 K for a magnetic-field change from 0 to 70 kOe. As a result, this new type of nanocapsule may be applied, in the temperature range studied, in cryogenic magnetic-refrigerator devices.

Liu, X. G.; Li, B.; Geng, D. Y.; Shi, C. X.; Yang, F.; Kang, D. J.; Zhang, Z. D.

2009-02-01

271

Optical microcavities and enhanced electroluminescence from electroformed Al-Al2O3-Ag diodes  

NASA Astrophysics Data System (ADS)

Electroluminescence (EL) and electron emission into vacuum (EM) occur when a non-destructive dielectric breakdown of Al-Al2O3-Ag diodes, electroforming, results in the development of a filamentary region in which current-voltage (I-V) characteristics exhibit voltage-controlled negative resistance. The temperature dependence of I-V curves, EM, and, particularly, EL of Al-Al2O3-Ag diodes with anodic Al2O3 thicknesses between 12 nm and 30 nm, has been studied. Two filters, a long-pass (LP) filter with transmission of photons with energies less than 3.0 eV and a short-pass (SP) filter with photon transmission between 3.0 and 4.0 eV, have been used to characterize EL. The voltage threshold for EL with the LP filter, VLP, is ˜1.5 V. VLP is nearly independent of Al2O3 thickness and of temperature and is 0.3-0.6 V less than the threshold voltage for EL for the SP filter, VSP. EL intensity is primarily between 1.8 and 3.0 eV when the bias voltage, VS ? 7 V. EL in the thinnest diodes is enhanced compared to EL in thicker diodes. For increasing VS, for diodes with the smallest Al2O3 thicknesses, there is a maximum EL intensity, LMX, at a voltage, VLMX, followed by a decrease to a plateau. LMX and EL intensity at 4.0 V in the plateau region depend exponentially on Al2O3 thickness. The ratio of LMX at 295 K for a diode with 12 nm of Al2O3 to LMX for a diode with 25 nm of Al2O3 is ˜140. The ratio of EL intensity with the LP filter to EL intensity with the SP filter, LP/SP, varies between ˜3 and ˜35; it depends on Al2O3 thickness and VS. Enhanced EL is attributed to the increase of the spontaneous emission rate of a dipole in a non-resonant optical microcavity. EL photons interact with the Ag and Al films to create surface plasmon polaritons (SPPs) at the metal-Al2O3 interfaces. SPPs generate large electromagnetic fields in the filamentary region of the electroformed Al-Al2O3-Ag diode, which then acts as an optical microcavity. A model is proposed for electronic processes in electroformed Al-Al2O3-Ag diodes.

Hickmott, T. W.

2013-12-01

272

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

273

Effects of Al(III) and Nano-Al13 Species on Malate Dehydrogenase Activity  

PubMed Central

The effects of different aluminum species on malate dehydrogenase (MDH) activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT) modified glass carbon electrode (GCE). The results showed that Al(III) and Al13 can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III) and Al13 concentration increase. Our study also found that the effects of Al(III) and Al13 on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules. PMID:22163924

Yang, Xiaodi; Cai, Ling; Peng, Yu; Li, Huihui; Chen, Rong Fu; Shen, Ren Fang

2011-01-01

274

Analog resistive switching behavior of Al/Nb2O5/Al device  

NASA Astrophysics Data System (ADS)

Resistive switching effects in metal–insulator–metal (MIM) structures are strongly influenced by the electrode materials. In this work a platinum-free symmetric Al/Nb2O5/Al device is compared to a device with platinum bottom electrode. For the device with the platinum bottom electrode, filamentary based resistive switching with good data retention was observed up to 125 °C. For the Al/Nb2O5/Al device, an area dependent pure electronic based resistive switching was observed. Electron trapping at the bottom electrode interface is responsible for the observed analog switching behavior which makes an Al/Nb2O5/Al device suitable for neuromorphic applications.

Mähne, H.; Wylezich, H.; Hanzig, F.; Slesazeck, S.; Rafaja, D.; Mikolajick, T.

2014-10-01

275

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

276

?-phase formation in NiAl and Ni2Al alloys  

NASA Astrophysics Data System (ADS)

The phase stability of bcc-like NiAl and Ni2Al with respect to phase transformations into the ? phase is examined by first-principles, full-potential, linear muffin-tin orbital method (FPLMTO), band-structure calculations. In agreement with experiment we find that bcc-like NiAl is stable, whereas Ni2Al is unstable. We have also performed some calculations in slightly disordered phases, and find that the disordering tends to inhibit the transformation. This supports the suggestion that a combined displacive/ordering transformation mechanism is involved in the phase transformations of the Ni2Al system. Calculated lattice parameters and the degree of internal shuffling of atoms for the ordered Ni2Al phase were found to be in excellent agreement with the experiment

Sanati, M.; Albers, R. C.; Pinski, F. J.

2001-06-01

277

The lowest ionization potentials of Al2  

NASA Technical Reports Server (NTRS)

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 (to Al2(+) X 2 sigma g +) of the Al2 X 3 pi u ground state is calculated to occur around 6.1 eV, in excellent agreement with the experimental range of 6.0 to 6.42 eV obtained in recent cluster ionization studies by Cox and co-workers. The second vertical ionization potential (to Al2(+) A 2 pi u) occurs near 6.4 eV, also within the experimental range. The adiabatic IP of 5.90 eV is in good agreement with the value of 5.8 to 6.1 eV deduced by Hanley and co-workers from the difference in thresholds between collision induced dissociation processes of Al3(+). The computed IP values are somewhat larger than those deduced from branching ratios in cluster fragmentation experiments by Jarrold and co-workers. The observation of an ionization threshold below 6.42 eV is shown to be incompatible with an Al2 ground electronic state assignment of 3 sigma g -, but the separation between the two lowest states of Al2 is so small that it is likely that both are populated in the experiments, so that this does not provide unambiguous support for the recent theoretical assignment of the ground state as 3 pi u.

Bauschlicher, Charles W., Jr.; Barnes, Leslie A.; Taylor, Peter R.

1988-01-01

278

The Stability of Al 11Sm3 (Al4Sm) Phases in the Al-Sm Binary System  

SciTech Connect

The relative stability of Al{sub 11}Sm{sub 3} (Al{sub 4}Sm) intermetallic phases was experimentally investigated through a series of heat treatments followed by microstructural, microchemical, and X-ray diffraction (XRD) analyses. The principal findings are that the high-temperature tetragonal phase is stable from 1655 to 1333 K and that the low-temperature orthorhombic phases, {alpha} and {gamma}, have no range of full stability but are metastable with respect to the crystalline Al and Sm reference states down to 0 K. Thermodynamic modeling is used to describe the relative energetics of stable and metastable phases along with the associated two-phase mixtures. Issues regarding transition energetics and kinetics are discussed.

S.H.Zhou; R.E. Napolitano

2007-06-01

279

Two-Phase (TiAl+TiCrAl) Coating Alloys for Titanium Aluminides  

NASA Technical Reports Server (NTRS)

A coating for protecting titanium aluminide alloys, including the TiAl gamma + Ti3Al (alpha(sub 2)) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000 C. is disclosed. This protective coating consists essentially of titanium, aluminum. and chromium in the following approximate atomic ratio: Ti(41.5-34.5)Al(49-53)Cr(9.5-12.5)

Brady, Michael P. (Inventor); Smialek, James L. (Inventor); Brindley, William J. (Inventor)

1998-01-01

280

The embrittlement of Al-Zn-Mg and Al-Mg alloys by water vapor  

Microsoft Academic Search

Al4.5Zn1.5Mg and Al5Mg were reacted in water-vapor saturated air (WVSA) at 120°C and tensile tested. After an initial loss of ductility with exposure time, probably caused by hydrogen embrittlement of the grain boundaries, between 15 hours and 25 hours exposure the mechanical properties of Al4.5Zn1.5Mg improved, this effect being due both to a reduced corrosion activity of the grain boundaries

C. D. S. Tuck

1985-01-01

281

Martensitic transformation in CVD NiAl and (Ni,Pt)Al bond coatings  

Microsoft Academic Search

The martensitic phase transformation in single-phase ?-NiAl and (Ni,Pt)Al coatings was investigated. After isothermal exposure to 1150 °C for 100 h, the ? phase in both types of coatings was transformed to a martensite phase during cooling to room temperature. Martensitic transformation was also observed in the (Ni,Pt)Al bond coat with and without a YSZ top layer after thermal cycling

Y Zhang; J. A Haynes; B. A Pint; I. G Wright; W. Y Lee

2003-01-01

282

Third-order elastic moduli of polycrystalline Al-Mg and Al-Cu alloys  

Microsoft Academic Search

The third-order elastic moduli of polycrystalline Al-rich Al-Mg and Al-Cu alloys are determined by measuring the changes in ultrasonic wave velocities under applied uniaxial stress. A solid-state pulse interferometer sensitive to a few parts per million for the relative velocity measurement was used. Pressure derivatives of elastic moduli and Gruneisen gamma are evaluated from the measured second- and third-order moduli.

V. K. Raju; P. J. Reddy

1981-01-01

283

Plasma spray processing of Al 2O 3\\/AlN composite powders  

Microsoft Academic Search

A novel method is proposed to prepare Al2O3\\/AlN composite powders. The composite powders were synthesized by direct nitridation of Al2O3 powders in Ar\\/N2 plasma. The processing characteristics were studied. The results show that the particle size of the initial materials, the nitrogen plasma gas flow rate and the power of the plasma generator are important factors that influence the phase

L. H Cao; K. A Khor; L Fu; F Boey

1999-01-01

284

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

...Front, aka Jabhat al-Nusrah, aka Jabhet al-Nusra, aka The Victory Front, aka Al Nusrah Front for the People of the Levant...the Secretary of State hereby amends the 2004 designation of al-Qa'ida in Iraq as a foreign terrorist...

2012-12-11

285

High temperature deformation of NiAl and CoAl  

NASA Technical Reports Server (NTRS)

The high temperature mechanical properties of the aluminides are reviewed with respect to their potential as high temperature structural materials. It is shown that NiAl and CoAl are substantially stronger than the pure metals Ni and Co at high temperatures and approach the strength of some superalloys, particularly when those superalloys are tested in "weak" directions. The factors that limit and control the high temperature strengths of NiAl and CoAl are examined to provide a basis for the development of intermetallic alloys of this type.

Nix, W. D.

1982-01-01

286

Deformation microstructures of [gamma]-TiAl in the Ti-46Al-2V alloy  

SciTech Connect

The intermetallic compound [gamma]-TiAl (L1[sub 0]) is potentially useful for elevated temperature structural applications. It has significant strength and reasonable ductility at high temperatures, but its applications are seriously affected by poor room temperature ductility. The deformation mechanisms of [gamma]-TiAl have been the topics of several papers in recent years. The effect of V addition on the deformation microstructures of [gamma]-TiAl in the two-phase ([alpha][sub 2] + [gamma]) Ti-46Al-2V (at.%) alloy at various temperature is reported in this paper.

Das, S.; Chaudhuri, K. (Univ. of Wisconsin, Madison, WI (United States). Dept. of Materials Science and Engineering)

1995-01-15

287

HYDROGEN ADSORPTION ON ?-TiAl (001) AND Ni/TiAl (001) SURFACES  

NASA Astrophysics Data System (ADS)

In this paper, we present first principles calculations of the energetic, electronic and magnetic properties of the variant termination of TiAl (001) and Ni/TiAl (001) surfaces with and without hydrogen atoms. The calculations have been performed within the density functional theory using full-potential linearized augmented plane wave method. The generalized gradient approximation (GGA) is utilized as the exchange-correlation energy. The octahedral site is the stable absorption site of H atom in the ?-TiAl system. This absorption reduces the cohesive energy of ?-TiAl system due to increase in the lattice constant. The surface energy for both TiAl (001) terminations is calculated. The stable adsorption site of H atoms on the variant termination of TiAl (001) surface is performed. The adsorption energy of hydrogen on Ti is more energetic than that on Al. The adsorption of H atom on both terminations of H/Ni/TiAl (001) is more preferable at the bridge site. The adsorption energies are enhanced on Ni atom due to the contraction between d-Ni bands and TiAl substrate band.

Mubarak, A. A. Karim; Alelaimi, Mahmoud

2014-04-01

288

Microsample testing of single crystalline Ti-52 at% Al and Ti-55.5 at% Al  

SciTech Connect

Dislocation activity in two-phase commercial TiAl alloys occurs most readily in the {gamma}-TiAl phase, and measurements of the CRSS of single crystalline {gamma}-TiAl provides a solid foundation for understanding the mechanical performance of these alloys. Single crystals of {gamma}-TiAl with greater than 54.5 at% Al have been grown using the optical float zone crystal growing technique, but single crystals with lower Al content, closer to that of commercial alloys, have not. In the present study, polycrystalline ingots of Ti-52 at% Al have been heat treated to form very large grains, and microsample tensile specimens, which have a nominal gage cross-section of 250{micro}m x 300{micro}m, a gage length of 250{micro}m and an overall length of 3 mm, have been machined from within single grains. Microsample high-temperature stress-strain curves for Ti-55.5 at% Al single crystals oriented along the [001] and [010] are presented. Tensile test results for Ti-52 at% Al tested at 1,073K along the[{bar 2}37], [{bar 1}73] and [{bar 3}44] orientations will also be discussed.

Zupan, M.; Dimiduk, D.M.; Hemker, K.J.

1999-07-01

289

Mechanical properties of Al and Al alloys and their relationship to interconnection reliability  

NASA Astrophysics Data System (ADS)

Pure Al, Al-3 wt %Si, and Al-15 at. % C films are characterized macroscopically in terms of yield stress and hardness and microscopically in terms of a grain structure to investigate the effects of Si and carbon additives to modify mechanical properties of the Al matrix. A theory is presented to estimate the yield stress of metal films. The experimental method is based on laser interferometer measurements of the varied substrate curvature involved with thermal treatment of a film-substrate composite. It is shown that carbon addition increases yield stress and hardness of Al, whereas Si addition decreases these properties. Carbon addition suppresses grain growth by 450 °C annealing as small as about 0.04 ?m. Reliability tests on Al and Al-alloy interconnects revealed that increased yield stress improves resistance against failures due to the stress at high temperatures and high current densities, but degrades resistance against cycled thermal shock. The double layered Al-C/Al structure was highly resistant against both thermal and current stress.

Ozawa, Kiyoshi

1993-01-01

290

Solid state reaction of Al and Zr in Al/Zr multilayers: A calorimetry study  

SciTech Connect

The exothermic, solid state reaction of Al and Zr has been studied in thick Al/Zr multilayers using Differential Scanning Calorimetry and X-ray diffraction. The multilayer samples were magnetron sputter deposited into highly textured alternate layers of Al and Zr with nominal composition Al{sub 3}Zr. The samples used in this study were 47{mu}m thick with a 427{Angstrom} period. When samples were isochronally scanned from 25 to 725C, a large exotherm at {approximately}350C was followed by one or two smaller exotherms at {approximately}650C. The first exotherm is dominated by a diffusion based reaction of Al and Zr that produces two phases in isochronal scans: amorphous Al-Zr and cubic Al{sub 3}Zr, and two additional phases in isothermal anneals: Al{sub 2}Zr and tetragonal Al{sub 3}Zr. The exothermic heat from this multi-phase reaction is measured using isochronal scans and isothermal anneals, and the heat flow is analyzed using a 1-D diffusion based model. An average activation energy and a diffusion constant are determined. In the isothermal scans, the total exothermic heat increases linearly with {radical}time, and layer thicknesses vary linearly with heat.

Blobaum, K.J.; Weihs, T.P.; Barbee, T.W. Jr.; Wall, M.A.

1995-04-14

291

Elastic and piezoelectric properties of AlN and LiAlO2 single crystals.  

PubMed

We have successfully grown high-quality AlN piezoelectric single crystal using the sublimation technique. Transparent crack-free boules of approximately 15 mm in diameter and 25 mm in length along the [0001] direction were obtained, with coloring from amber to dark brown depending on growth temperature. Full sets of material parameters of grown AlN and commercially available LiAlO(2) bulk crystals were measured at room temperature. Temperature coefficients of the material parameters of LiAlO(2) were also obtained in a temperature range from -70 to +50 degrees C. PMID:20378443

Sotnikov, Andrey; Schmidt, Hagen; Weihnacht, Manfred; Smirnova, Elena; Chemekova, Tatiana; Makarov, Yuri

2010-04-01

292

Possible Involvement of Al-Induced Electrical Signals in Al Tolerance in Wheat.  

PubMed Central

The relationship between Al-induced depolarization of root-cell transmembrane electrical potentials (Em) and Al tolerance in wheat (Triticum aestivum L.) was investigated. Al exposure induced depolarizations of Em in the Al-tolerant wheat cultivars Atlas and ET3, but not in the Al-sensitive wheat cultivars Scout and ES3. The depolarizations of Em occured in root cap cells and as far back as 10 mm from the root tip. The depolarization was specific to Al3+; no depolarization was observed when roots were exposed to the rhizotoxic trivalent cation La3+. The Al-induced depolarization occurred in the presence of anion-channel antagonists that blocked the release of malate, indicating that the depolarization is not due to the electrogenic efflux of malate2-. K+-induced depolarizations in the root cap were of the same magnitude as Al-induced depolarizations, but did not trigger malate release, indicating that Al-induced depolarization of root cap cell membrane potentials is probably linked to, but is not sufficient to trigger, malate release. PMID:12223834

Papernik, L. A.; Kochian, L. V.

1997-01-01

293

The PtAl- and PtAl2- anions: Theoretical and photoelectron spectroscopic characterization  

NASA Astrophysics Data System (ADS)

We report a joint photoelectron spectroscopic and theoretical study of the PtAl- and PtAl2- anions. The ground state structures and electronic configurations of these species were identified to be C?v, 1?+ for PtAl-, and C2v, 2B1 for PtAl2-. Structured anion photoelectron spectra of these clusters were recorded and interpreted using ab initio calculations. Good agreement between theory and experiment was found. All experimental features were successfully assigned to one-electron transitions from the ground state of the anions to the ground or excited states of the corresponding neutral species.

Zhang, Xinxing; Ganteför, Gerd; Bowen, Kit H.; Alexandrova, Anastassia N.

2014-04-01

294

Magnetron sputtered nc-Al/alpha-Al2O3 nanocomposite thin films for nonvolatile memory application.  

PubMed

In this paper, we developed nc-Al/a-Al2O3 nanocomposite thin films using magnetron sputtering. The nc-Al/a-Al2O3 films were sputtered on p-type Si substrates from pure Al target in gas mixture of Ar and O2. X-ray photoelectron spectroscopy and high resolution transmission electron microscope studies confirm that the nanocrystalline Al are embedded in amorphous Al2O3 matrix thus nc-Al/ a-Al2O3 nanocomposite forms. This nanocomposite thin film exhibits memory effect as a result of charge trapping. PMID:19916417

Li, Yibin; Zhang, Sam; Liu, Y; Chen, T P; Sritharan, Thirumany; Xu, Cong

2009-07-01

295

Sintering Behavior and Mechanical Properties of NiAl, Al2O3, and NiAl-Al2O3 Composites  

NASA Astrophysics Data System (ADS)

It is commonly known that the properties of sintered materials are strongly related to technological conditions of the densification process. This paper shows the sintering behavior of a NiAl-Al2O3 composite, and its individual components sintered separately. Each kind of material was processed via the powder metallurgy route (hot pressing). The progress of sintering at different stages of the process was tested. Changes in the microstructure were examined using scanning and transmission electron microscopy. Metal-ceramics interface was clean and no additional phases were detected. Correlation between the microstructure, density, and mechanical properties of the sintered materials was analyzed. The values of elastic constants of NiAl/Al2O3 were close to intermetallic ones due to the volume content of the NiAl phase particularly at low densities, where small alumina particles had no impact on the composite's stiffness. The influence of the external pressure of 30 MPa seemed crucial for obtaining satisfactory stiffness for three kinds of the studied materials which were characterized by a high dense microstructure with a low number of isolated spherical pores.

Chmielewski, M.; Nosewicz, S.; Pietrzak, K.; Rojek, J.; Strojny-N?dza, A.; Mackiewicz, S.; Dutkiewicz, J.

2014-08-01

296

Photoemission from Al Alloys during Tensile Deformation  

NASA Astrophysics Data System (ADS)

We report simultaneous measurements of strain and photoelectron emission intensity from high purity Al (1350), Al-Mg (5052), Al-Mn (3003), Al-Cu (2024) and Al-Mg-Si (6061) alloys under uniaxial tension due to pulsed excimer laser radiation (248-nm). The photoemission signals are sensitive to deformation-induced changes in surface morphology, including the formation of slip lines and slip bands. In the early stages of deformation (strain Â¡Ü 0.03), the photoemission intensity increases gradually in a nonlinear fashion. Depending on sample composition and heat treatment, the photoemission intensity subsequently grows linearly until the accumulated strain reaches about 0.20. Finally, the photoemission intensity increases parabolically until failure. The onset of strain localization corresponds to the transition from linear to parabolic growth. A constitutional model incorporating microstructure evolution and work-hardening during tensile deformation is proposed to qualitatively interpret the growth of the photoemission signals as a function of strain. The photoemission signals from the tested alloys are interpreted in terms of the effect of surface treatment, work function, microstructure, and composition on the development of dislocation structures during deformation.

Cai, Mingdong; Langford, Stephen; Levine, Lyle; Dickinson, Thomas

2004-03-01

297

First-principle study of adhesion, wetting and bonding on Al/Al3V(001) interface  

NASA Astrophysics Data System (ADS)

The adhesion, wetting, and bonding on fcc-Al(001)/D022-Al3V(001) interface were investigated using density functional calculations. Considering different terminations of Al3V(001) (Al- and Al + V-terminated) and stacking sites (center-, hollow- and top-sites), six Al/Al3V(001) models were calculated. For the models with same stacking site, Al + V-terminated model has larger work of adhesion (Wad) than the Al-terminated one. For the models with same termination, the work of adhesion decreases, and the interface energy (?int) increases as the order of top-, bridge- and center-sites. Al-terminated-center-sited and Al + V-terminated-center-sited models are more stable among six models. After complete structure relaxation, both models have the same epitaxial stacking style. Therefore, the both models can be regarded as of the same and most stable one (noted as CSI model), but separating along Al-Al and Al-Al+V inter-planes. Based on the perfect wetting and strong adhesion in CSI model, the heterogeneous nucleation of ?-Al on Al3V(001) was interpreted in terms of crystallography and thermodynamics. The interfacial bonding was discussed with analysis of valence electron density distribution and partial density of states (PDOS). The bonding is mainly contributed from AlV covalent bonds and AlAl metallic interactions.

Li, Jian; Qi, Yuning; Zhang, Ming; Zhou, Yong; Li, Xiao

2014-06-01

298

Early Solar Nebula Condensates with Canonical, Not Supracanonical, Initial 26Al/27Al Ratios  

NASA Astrophysics Data System (ADS)

The short-lived radionuclide 26Al existed throughout the solar nebula 4.57 Ga ago, and the initial abundance ratio (26Al/27Al)0, as inferred from magnesium isotopic compositions of calcium-aluminum-rich inclusions (CAIs) in chondritic meteorites, has become a benchmark for understanding early solar system chronology. Internal mineral isochrons in most CAIs measured by secondary ion mass spectrometry (SIMS) give (26Al/27Al)0 ~ (4-5) × 10-5, called "canonical." Some recent high-precision analyses of (1) bulk CAIs measured by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS), (2) individual CAI minerals and their mixtures measured by laser-ablation MC-ICPMS, and (3) internal isochrons measured by multicollector (MC)-SIMS indicated a somewhat higher "supracanonical" (26Al/27Al)0 ranging from (5.85 ± 0.05) × 10-5 to >7 × 10-5. These measurements were done on coarse-grained Type B and Type A CAIs that probably formed by recrystallization and/or melting of fine-grained condensate precursors. Thus the supracanonical ratios might record an earlier event, the actual nebular condensation of the CAI precursors. We tested this idea by performing in situ high-precision magnesium isotope measurements of individual minerals in a fine-grained CAI whose structures and volatility-fractionated trace element abundances mark it as a primary solar nebula condensate. Such CAIs are ideal candidates for the fine-grained precursors to the coarse-grained CAIs, and thus should best preserve a supracanonical ratio. Yet, our measured internal isochron yields (26Al/27Al)0 = (5.27 ± 0.17) × 10-5. Thus our data do not support the existence of supracanonical (26Al/27Al)0 = (5.85-7) × 10-5. There may not have been a significant time interval between condensation of the CAI precursors and their subsequent melting into coarse-grained CAIs.

MacPherson, G. J.; Bullock, E. S.; Janney, P. E.; Kita, N. T.; Ushikubo, T.; Davis, A. M.; Wadhwa, M.; Krot, A. N.

2010-03-01

299

ALS and Frontotemporal Dysfunction: A Review  

PubMed Central

Though once believed to be a disease that was limited to the motor system, it is now apparent that amyotrophic lateral sclerosis (ALS) may be associated with cognitive changes in some patients. Changes are consistent with frontotemporal dysfunction, and may range from mild abnormalities only recognized with formal neuropsychological testing, to profound frontotemporal dementia (FTD). Executive function, behavior, and language are the most likely areas to be involved. Screening helpful in detecting abnormalities includes verbal or categorical fluency, behavioral inventories filled out by the caregiver, and evaluation for the presence of depression and pseudobulbar affect. Patients with cognitive dysfunction have shortened survival and may be less compliant with recommendations regarding use of feeding tubes and noninvasive ventilation. Evolving knowledge of genetic and pathological links between ALS and FTD has allowed us to better understand the overlapping spectrum of ALS and FTD. PMID:22919484

Achi, Eugene Y.; Rudnicki, Stacy A.

2012-01-01

300

Textures of Ta/Al multilayer films  

NASA Astrophysics Data System (ADS)

Ta/Al multilayer films with a modulation wavelength of 7.0 nm were grown using magnetron sputtering. The Bragg ?-2? scan pattern and the plate film photograph of x-ray diffraction reveal that the sample has Ta(110) and A1(111) axial textures with a mosaic spread of about ±5° and coherency strains. The structure change of the multilayer sample after annealing at 550 °C for 2 h is determined by the plate film photography of x-ray diffraction to study the thermal stability. It is found that after annealing a large amount of Ta and Al atoms at the interfaces are combined into TaAl3 with [(202)+(002)] textures.

Yuan, X. Y.; Wu, Z. Q.; Hu, A.; Jiang, S. S.; Qiu, Y.; Khatanova, N. A.; Ilyushin, R. S.

1993-04-01

301

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. PMID:23629963

King, Oliver D.

2013-01-01

302

[Al-Biruni--a universal scientist].  

PubMed

Al-Biruni's was of Persian descent. He was born in Horesmiya and had studied mathematics, history and medicine. Acquiring knowledge from these sciences, he wrote an outstanding work on chronology of several nations and devoted it to Ziyarit ruler Kabus. He made a chronological overview of calendars from many nations, including Persians, Greeks, Egyptians, Jews, Melkitian and Nestorian Christians, Sabeyaans as well as the old Arabs. Data presented in the work, according to the later authors, were taken from very reliable sources. He was contemporary of Ibn-Sina, and thanks to their friendship, they have discussed very much miscellaneous topics. He belonged to the group of scholars, taken by Gaznevian Soultan Mahmud to a long journey to India. Afterwards Al-Biruni wrote and published detailed work "Description of India"--a work on cultural history of India. Due to excellent abilities of Al-Biruni as a philosopher and scholar, there are still significant and reliable notes about buddhistic philosophy, structure of castes and Brahmans' life style. In this Al-Biruni's masterpiece, there are many comparative analysis of Suffism and certain Indian philosophical methods. Al-Biruni's most important work is "Pharmacopoeia"--"Kitab al-saydala", which brilliantly describes all medicaments. This work has been published in many languages. He also wrote few works on astronomy and astrology. In those works he has explained some astrological events through scientific approach in a such peculiar way that nobody has ever explained before. He was also interested in sciences like geology, mineralology, geography, mathematics, psychology and many others. PMID:10386051

Kujundzi?, E; Masi?, I

1999-01-01

303

Mathematik als Geisteswissenschaft Der Mathematikschädigung dialogisch vorbeugen  

NASA Astrophysics Data System (ADS)

Ursprünglich wollte ich Architekt werden getreu den Vorbildern von Vater und Großvater. Darum zeichnete ich bereits als neunjähriges Kind Pläne von Häusern in der Art, wie ich sie oft zu sehen bekam. Ein ausgemustertes Holzdreieck mit einem rechten und zwei halben rechten Winkeln war das einzige Konstruktionswerkzeug, das ich damals besaß und mit dem ich mich ans Werk machte. Zuerst einmal war da natürlich ein Rechteck als Grundriss des Hauses zu zeichnen: Eine Seite, ein rechter Winkel, die zweite Seite, wieder ein rechterWinkel, die dritte Seite in gleicher Länge wie die erste und dann der dritte rechte Winkel, dessen letzter Schenkel die vierte Seite gab.

Gallin, Peter

304

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

305

Synthesis of nanostructured AlN by solid state reaction of Al and diaminomaleonitrile  

SciTech Connect

The solid state reaction of diaminomaleonitrile (DAMN) with aluminum via both mechanochemical and thermal treatment routes was studied by X-ray diffraction and Fourier transform infrared spectroscopy. During the milling process, the reaction starts with the deammoniation of the DAMN molecules, followed by the formation of nanostructured AlN powder as the main solid product after milling for 7 h. The reactivity of the mixed powder was also investigated during the conventional thermal treatment process using differential scanning calorimetry, derivative thermogravimetry and thermogravimetric analysis. The results reveal that DAMN starts to polymerize at 192 Degree-Sign C by the elimination of the amine groups. Furthermore, increasing the annealing temperature leads to the formation of a nitrogen-containing carbonaceous material with the structure similar to non-crystalline carbon. However, no evidence for the formation of AlN was observed in the annealed samples even at temperatures as high as the Al melting point. - Graphical abstract: AlN nanoparticles obtained after milling of Al and diaminomaleonitrile (DAMN) for 12 h. Highlights: Black-Right-Pointing-Pointer Solid state reaction of diaminomaleonitrile (DAMN) with Al was studied via mechanochemical and thermal treatment routs. Black-Right-Pointing-Pointer Nanocrystalline AlN was successfully synthesized by the mechanochemical process. Black-Right-Pointing-Pointer The C/N material was formed by polymerization of DAMN during the thermal treatment process. Black-Right-Pointing-Pointer No reaction between DAMN and Al was detected during the thermal treatment method.

Rounaghi, S.A., E-mail: s.a.rounaghi@gmail.com [Department of Materials Engineering, Ferdowsi University of Mashhad. P.O. Box no. 91775-1111, Mashhad (Iran, Islamic Republic of); IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); Eshghi, H., E-mail: heshghi@ferdowsi.um.ac.ir [Department of Chemistry, Ferdowsi University of Mashhad. P.O. Box no. 91775-1436, Mashhad (Iran, Islamic Republic of); Kiani Rashid, A.R.; Vahdati Khaki, J. [Department of Materials Engineering, Ferdowsi University of Mashhad. P.O. Box no. 91775-1111, Mashhad (Iran, Islamic Republic of)] [Department of Materials Engineering, Ferdowsi University of Mashhad. P.O. Box no. 91775-1111, Mashhad (Iran, Islamic Republic of); Samadi Khoshkhoo, M.; Scudino, S. [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany)] [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); Eckert, J. [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany) [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); TU Dresden, Institut fuer Werkstoffwissenschaft, Dresden D-01062 (Germany)

2013-02-15

306

AlAskA Justice Forum University of AlAskA AnchorAge  

E-print Network

AlAskA Justice Forum University of AlAskA AnchorAge A PUblicAtion of the JUstice center Fall 2008 to Alaska State Troopers Marny Rivera, Andr� B. Rosay, Darryl S. Wood, Greg Postle, and Katherine Te violence is an undeniable urban and rural problem in Alaska and the nation. Detailed data on domestic

Pantaleone, Jim

307

University of AlAskA AnchorAge AlAskA Justice Forum  

E-print Network

University of AlAskA AnchorAge AlAskA Justice Forum A PUblicAtion of the JUstice center Fall 2013 in Alaska and nationally (page 2). � An update on the work of the Alaska Prisoner Reentry Task Force (page 5 Collateral Consequences and Reentry in Alaska: An Update Deborah Periman "Our legal system has created

Pantaleone, Jim

308

University of AlAskA AnchorAge AlAskA Justice Forum  

E-print Network

University of AlAskA AnchorAge AlAskA Justice Forum A PUblicAtion of the JUstice center Spring 2013 respected professionals have retired after lengthy careers working with troubled youth inAlaska. For this issue of the Alaska Justice Forum, we asked three of these professionals to provide reflections from

Pantaleone, Jim

309

University of AlAskA AnchorAge AlAskA Justice Forum  

E-print Network

University of AlAskA AnchorAge AlAskA Justice Forum A PUblicAtion of the JUstice center Summer 2013 Vol. 30, No. 2 Please see Alcohol, page 13 Reducing Sales of Alcohol to Underage Persons in Alaska within a few hours) in the past month, more than one quarter of youth in public high schools in Alaska

Pantaleone, Jim

310

^27Al-NMR Study of the Spinel Compound CoAl2O4  

NASA Astrophysics Data System (ADS)

CoAl2O4, a geometrically frustrated magnet, is believed to be located in the vicinity of a quantum melting point of the AFM ordered state. In CoAl2O4, magnetic frustration originates from Co^2+(S = 3/2) spins on the tetrahedral A-site via non-magnetic Al ions occupying the octahedral B-site. To study the magnetic properties of CoAl2O4 from a microscopic point of view, we have carried out ^27Al-NMR measurements using a well-characterized powder sample of CoAl2O4. The temperature dependence of the magnetic susceptibility ? shows a broad peak around 15 K and does not show any difference in zero-field-cooled and field-cooled measurements. ^27Al-NMR spectra at 9.3 MHz (H = 0.84 T) show seven peaks characterized by quadrupolar splitting with ?Q= 0.55 MHz at temperatures above 10 K. Below 10 K, the spectrum broadens suddenly. We also observe a peak of 1/T1 of ^27Al at 10 K. These NMR results clearly indicate magnetic ordering at 10 K, although ? does not exhibit any signature of long-range magnetic ordering.

Roy, Beas; Pandey, Abhishek; Johnston, David C.; Furukawa, Yuji

2013-03-01

311

ccsd00004518, Precipitation kinetics of Al 3 Zr and Al 3 Sc in  

E-print Network

ccsd­00004518, version 2 ­ 21 Mar 2005 Precipitation kinetics of Al 3 Zr and Al 3 Sc in aluminum/Si#18;ege, 31-33, rue de la F#19;ed#19;eration, 75752 Paris cedex 15, France Abstract Precipitation dynamics, a mesoscopic modeling technique which describes the various stages of homogeneous precipitation

312

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

313

Bakker is in Canada al op stage geweest als de begeleider van  

E-print Network

2828 actIeve stUDeNt Bakker is in Canada al op stage geweest als de begeleider van toen iets nieuws ploeteren naar `het dak der aarde'. "Bij iedere bocht moest ik bijkomen", bekent Bakker. "En die sherpa: bij onder- zoeken naar bijvoorbeeld de vocht- huishouding van de nieren of, in het geval van Bakker

Twente, Universiteit

314

Characterization of nanophase Al-oxide/Al powders by electron energy-loss spectroscopy.  

PubMed

Al nanoparticles were prepared by the inert gas condensation method. After passivation with oxygen and air exposure we obtained a powdered sample of an Al-oxide/Al nanocomposite material. In the present paper we describe the use of the electron energy-loss spectroscopy (EELS) technique in a transmission electron microscope to characterize such nanostructured powders compared with a microcrystalline commercial aluminium foil. Energy-filtered images showed the presence of an alumina overlayer of approximately 4 nm covering the aluminium nanoparticles (23 nm in diameter). EELS analysis enabled us to determine the total amount of Al2O3 and metallic Al and the structure of the alumina passivation overlayer in the sample. In particular, the extended energy-loss fine structure analysis of the data showed a major presence of Al tetrahedrally coordinated with oxygen in the alumina passivation layer of Al nanoparticles instead of the octahedral coordination found for a conventional Al foil. This surprising effect has been attributed to the nanoscopic character of the grains. The analysis of the electron-loss near-edge structure also determines the presence of a certain degree of aggregation in this kind of powdered sample as result of the coalescence of the nanocrystalline grains. The procedure presented here may have the potential to solve other problems during characterization of nanostructured materials. PMID:9767485

Fernández; Sánchez-López; Caballero; Martin; Vacher; Ponsonnet

1998-08-01

315

Melting, Processing, and Properties of Disordered Fe-Al and Fe-Al-C Based Alloys  

NASA Astrophysics Data System (ADS)

This article presents a part of the research work conducted in our laboratory to develop lightweight steels based on Fe-Al alloys containing 7 wt.% and 9 wt.% aluminum for construction of advanced lightweight ground transportation systems, such as automotive vehicles and heavy-haul truck, and for civil engineering construction, such as bridges, tunnels, and buildings. The melting and casting of sound, porosity-free ingots of Fe-Al-based alloys was accomplished by a newly developed cost-effective technique. The technique consists of using a special flux cover and proprietary charging schedule during air induction melting. These alloys were also produced using a vacuum induction melting (VIM) process for comparison purposes. The effect of aluminum (7 wt.% and 9 wt.%) on melting, processing, and properties of disordered solid solution Fe-Al alloys has been studied in detail. Fe-7 wt.% Al alloy could be produced using air induction melting with a flux cover with the properties comparable to the alloy produced through the VIM route. This material could be further processed through hot and cold working to produce sheets and thin foils. The cold-rolled and annealed sheet exhibited excellent room-temperature ductility. The role of carbon in Fe-7 wt.% Al alloys has also been examined. The results indicate that Fe-Al and Fe-Al-C alloys containing about 7 wt.% Al are potential lightweight steels.

Satya Prasad, V. V.; Khaple, Shivkumar; Baligidad, R. G.

2014-09-01

316

modified source procedure of Kirwan et al. [6] and Wais et al. [7] because source memory is neither necessary nor  

E-print Network

modified source procedure of Kirwan et al. [6] and Wais et al. [7] because source memory is neither predicts recollection. J. Neurosci. 28, 10541­10548 7 Wais, P.E. et al. (2010) In search of recollection

Wixted, John T.

317

Al/sub 2/O/sub 3/ adherence on CoCrAl alloys  

SciTech Connect

Adherence of protective oxides on NiCrAl and CoCrAl superalloys has been promoted by a dispersion of a highly oxygen reactive element or its oxide being produced within the protection system. Two aspects of this subject are investigated here: the use of Al/sub 2/O/sub 3/ as both the dispersion and protective oxide; and the production of an HfO/sub 2/ dispersion while simultaneously aluminizing the alloy. It was found that an Al/sub 2/O/sub 3/ dispersion will act to promote the adherence of an external scale of Al/sub 2/O/sub 3/ to a degree comparable to previously tested dispersions and an HfO/sub 2/ dispersion comparable to that produced by a Rhines pack treatment is produced during aluminization.

Kingsley, L.M.

1980-04-01

318

In situ microscopy of rapidly heated nano-Al and nano-Al/WO3 thermites  

NASA Astrophysics Data System (ADS)

The initiation and reaction mechanism of nano-Al and nano-Al thermites in rapid heating environments is investigated in this work. A semiconductor-based grid/stage was used, capable of in situ heating of a sample from room temperature to 1473 K, and at a rate of 106 K/s, inside an electron microscope. Nano-Al was rapidly heated in a transmission electron microscope, and before and after images indicate that the aluminum migrates through the shell, consistent with a diffusion-based mechanism. A nano-Al/WO3 composite was then heated in a scanning electron microscope. The results indicate that a reactive sintering mechanism is occurring for the nano-Al/WO3 thermite, as the products are found to be in surface contact and significantly deformed after the heating pulse.

Sullivan, Kyle T.; Chiou, Wen-An; Fiore, Richard; Zachariah, Michael R.

2010-09-01

319

Characteristics of vertically stacked Nb/Al/AlN/Nb Josephson junctions  

NASA Astrophysics Data System (ADS)

Vertically stacked Josephson junctions have been fabricated with Nb/Al/AlN as a base unit. The reactively sputtered AlN layer is deposited much more quickly than the lengthy thermal oxidation of Al. AlN is therefore a favorable candidate for stacked junctions consisting of many layers. Lift-off patterning the junctions avoids the problem of anodizing or etching through many layers. The superconducting layer thickness is chosen to be small with respect to the London penetration depth to allow coupling of the magnetic field in the adjacent insulating layers. Current versus voltage characteristics of these devices will be presented. In addition, critical current as a function of applied magnetic field will be presented.

Maglic, S. R.; Thomas, C. D.; Song, S. N.; Ulmer, M. P.; Ketterson, J. B.

1996-03-01

320

Temperature dependence of the activity of Al in dilute Ni(Al) solid solutions  

SciTech Connect

Activities of dilute Al solid solutions in Ni are determined from a first-principles approach. Both thermal lattice vibration and electronic contributions to free energies are considered and compared. Vibrational contributions tend to dominate the temperature dependencies of the free energies, though electron thermal effects are significant. Calculations show opposing temperature trends for the formation enthalpies and entropies, leading to a partial cancellation of their role in the overall energetics. Nevertheless, their remaining temperature effects are strong. Over the temperature range, 400 KAl activity coefficient varies by 15 orders of magnitude, due to the relative strength of Al-Ni and Al-Al bonds. The Ni activity coefficient only varies less than 4% over the same range. Calculational results compare well with available experimental data. The thermodynamic principles elucidated from the calculations are used to provide a fundamental interpretation.

Jiang Yong; Smith, J. R. [Delphi Research Labs, Shelby Township, Michigan 48315 (United States); Evans, A. G. [University of California, Santa Barbara, California 93106 (United States)

2006-12-01

321

27Al-NQR Study on Novel Phase Transition in CeOs2Al10  

NASA Astrophysics Data System (ADS)

We have performed 27Al-NQR measurements in CeOs2Al10 which exhibits a novel phase transition at T0=29 K The NQR parameters determined for all the Al sites in ambient pressure were compared with those in CeRu2Al10 with T0=27 K and CeFe2Al10 with no phase transition. The distinct NQR splitting just below T0=32.5 K under pressure 0.66 GPa ensures an enhancement of T0 and a homogeneous transition. Despite the increase of T0, the nuclear spin-lattice relaxation rate 1/Tl is suppressed over whole range of temperature than in ambient pressure. The characteristic features of no critical slowing down at T0 and of the remarkable decrease of 1/T1T starting at T > T0 become prominent under pressure, suggesting an approach to Kondo semiconductor in a valence fluctuation regime.

Matsumura, M.; Inagaki, T.; Kato, H.; Nishioka, T.; Tanida, H.; Sera, M.

2012-12-01

322

Formation of gamma'-Ni3Al via the Peritectoid Reaction: gamma plus beta (+Al2O3) equals gamma'(+Al2O3)  

NASA Technical Reports Server (NTRS)

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma'-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3) = gamma + beta (+ Al2O3), at 1640 plus or minus 1 K and a liquid composition of 24.8 plus or minus 0.2 at.%Al (at an unknown oxygen content). The {gamma + beta + Al2O3} phase field is stable over the temperature range 1633 - 1640 K, and gamma'-Ni3Al forms via the peritectiod, gamma + beta (+ Al2O3) = gamma'(+ Al2O3), at 1633 plus or minus 1 K. This behavior is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma'-Ni3Al phase field.

Copland, Evan

2008-01-01

323

Formation of gamma(sup prime)-Ni3Al via the Peritectoid Reaction: gamma + beta (+ Al2O3)=gamma(sup prime)(+ Al2O3)  

NASA Technical Reports Server (NTRS)

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8-32 at.%Al and temperature range T=1400-1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma(sup prime)-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3)=gamma + Beta(+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%al (at an unknown oxygen content). The {gamma + Beta (+Al2O3} phase field is stable over the temperature range 1633-1640 K, and gamma(sup prime)-Ni3Al forms via the peritectoid, gamma + Beta (+ Al2O3)=gamma(sup prime) (+ Al2O3), at 1633 +/- 1 K. This behavior is consistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(sup prime)-Ni2Al phase field.

Copeland, Evan

2008-01-01

324

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

325

Combating Al Qaeda's Splinters: Mishandling Suicide Terrorism  

Microsoft Academic Search

The past three years saw more suicide attacks than the last quarter century. Most of these were religiously motivated. While most Westerners have imagined a tightly coordinated transnational terrorist organization headed by Al Qaeda, it seems more likely that nations under attack face a set of largely autonomous groups and cells pursuing their own regional aims. Repeated suicide actions show

Scott Atran

2004-01-01

326

Kieffer et al., p. 1 Volcanologie -Volcanology  

E-print Network

Kieffer et al., p. 1 Volcanologie - Volcanology Reconnaissance de l'ignimbrite campanienne près du golfe d e Policastro (Italie), jusqu'à 150 km de sa zone d'émission. Implications volcanologiques et paléoenvironnementales. Recognition of the Campanian Ignimbrite near the Gulf of Policastro (Basilicata, Italy), 150 km

Boyer, Edmond

327

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

328

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

329

Al/Cl2 molten salt battery  

NASA Technical Reports Server (NTRS)

Molten salt battery has been developed with theoretical energy density of 5.2 j/kg (650 W-h/lb). Battery, which operates at 150 C, can be used in primary mode or as rechargeable battery. Battery has aluminum anode and chlorine cathode. Electrolyte is mixture of AlCl3, NaCl, and some alkali metal halide such as KCl.

Giner, J.

1972-01-01

330

AL ASK A SALMON alaska Salmon  

E-print Network

189 AL ASK A SALMON UNIT 13 alaska Salmon INTRODUCTION Pacific salmon have played an important and pivotal role in the history of Alaska. Salmon, along with mining, timber, and furs, were the keystone of residents and visitors to Alaska. Alaska native peoples and their heritage have a long, colorful bond

331

Al Magnifico Rettore Prof. Luigi Frati  

E-print Network

RS.U. scriventi comunicano con la presente che l'Assemblea R.S.U. del 02/02/2010 all'unanimità ha CCNL 2006/2009 in quanto in completo disaccordo nel metodo. Nel merito questa RSU CHIEDE ALL", fermo restando che questa RSU si riserva ulteriori proposte ed iniziative al riguardo. Cordiali saluti

Guidoni, Leonardo

332

(12) United States Patent Jalali et al.  

E-print Network

. Ultrafast analog-to-digital (A/D) conversion and digital-to-analog I/A) conversion are achieved,288,659 B1 Sep. 11, 2001 (54) DATA CONVERSION USING TIME MANIPULATION (75) Inventors: Bahrarn Jalali. ........................ .. 385/123 OTHER PUBLICATIONS Frankel et al., High--performancephotonic analogue--digital converter

Jalali. Bahram

333

Page et al. 1 POINTS IN QUESTION  

E-print Network

switches; Hafner & Nadler (1988), whose data require at most two host switches out of nine speciation events (Page, 1990); and his own studies (Barker, 1991) of 11 species of rock- #12;Page et al. 3 wallaby lice for which he found little evidence for cospeciation. It is hard to see how Barker arrived at his

Clayton, Dale H.

334

Diffusion bonding of ?-TiAl sheets  

Microsoft Academic Search

Using advanced ?-TiAl based alloys and various ingot and powder metallurgical routes, several aerospace engine components are now being developed. Further application of this material in the aerospace industry can only be implemented provided that successful joining and cost effective fabrication methods for this material are developed. In this context, diffusion bonding and superplastic forming of this material is considered

G. Çm; H. Clemens; R. Gerling; M. Koçak

1999-01-01

335

United States Patent [191 Jalali et al.  

E-print Network

use simple path length dilferences. either in free space or in ?bers to achieve true-time delay. See/1994 Glance et a]. ........................ 385/27 X OTHER PUBLICATIONS LJ Lembo et al.. "Low-Loss into a plurality of wavelength components. fed back on optically time-delayed feedback paths to a multiplexer which

Jalali. Bahram

336

(12) United States Patent Black et al.  

E-print Network

Alamos, New Mexico. After one test explos:ion, two atomic .bombs: were dropped on the Japanese cities of Hiroshima (6 Aug 1945) and Nagasaki (9 _:Aug 1945); the bomb dropped on - .Hiroshima was as. powerful as metric tons of TNT, that on equivalent to 22.000 metrie tOI"ll The USSR first detbnated al'l atomic 1949

Shamos, Michael I.

337

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

338

(12) United States Patent Reardan et al.  

E-print Network

patients receiving the drug. Abuses are identified by monitor- ing data in the database for prescription and method utilizes a central phannacy and database to track all prescriptions for a sensi- tive drug(12) United States Patent Reardan et al. (54) SENSITIVE DRUG DISTRIBUTION SYSTEM AND METHOD (75

Shamos, Michael I.

339

Ternary Dy-Er-Al magnetic refrigerants  

DOEpatents

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

340

Al Eskan disease: Persian Gulf syndrome.  

PubMed

This article examines the potential relationship between Al Eskan disease and the Persian Gulf syndrome. Al Eskan disease, reported in Military Medicine in 1992, is a novel and previously unreported condition triggered by the exceptionally fine sand dust of the Central and Eastern Saudi Arabian peninsula. We repeat our study of the pathogenesis of Al Eskan disease to include the ultrastructural and microanalytical study of the sand, aerobiological studies of the Kingdom of Saudi Arabia, and the etiology, symptoms, and prevalence of the disease. We conclude that immunodepression resulting from the continued presence of sand particles less than 1 micron in diameter in the lungs and bodies of Persian Gulf veterans explains not only the symptoms of the hyperegic lung condition of phase I and the symptoms of phase II of Al Eskan disease, but also provides an important clue to a common factor in most cases of Persian Gulf illnesses. We include a discussion of most of the commonly suspected agents in the Persian Gulf syndrome. In this case, we conclude that each of these factors, such as oil well fires, old-world diseases, or depleted uranium, are probably adjuvant or contributing causes. The only common exposure that would lead to recognition of the Persian Gulf syndrome as a single medical condition, rather than a catch-all phrase for unrelated conditions, appears to be exposure to the ubiquitous, fine sand of the area, and a resulting immunosuppression that is aggravated by opportunistic infections and other nonmicrobial ailments. PMID:9002695

Korényi-Both, A L; Korényi-Both, A L; Juncer, D J

1997-01-01

341

The Rail Gun Muad Al Khaldi  

E-print Network

The Rail Gun Muad Al Khaldi Department of Electrical Engineering King Fahd University of Petroleum and Minerals Abstract- The rail gun is one of promising ways of launching projectiles. Recently, many. In this project, I am going to investigate the construction of electromagnetic rail guns, the way the function

Masoudi, Husain M.

342

Football team al-most snatches de-  

E-print Network

Inside &ONLINE Whew! Football team al- most snatches de- feat from the jaws of victory, but hangs by the museum. Thefinancialgiftisthesinglelargest donation in the history of the Har- vardArtMuseum. The Art to get their genome sequenced but also to share that information, along with their medical histories

343

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

344

Abrasive wear behavior of NiAl and NiAl-TiB2 composites  

SciTech Connect

Abrasive wear of NiAl and NiAl with 10, 20, and 40 vol.% TiB2 has been investigated using particles of different types and sizes. The addition of TiB2 as a particulate reinforcement to NiAl increases the hardness of the composite with respect to NiAl, and reduces the wear rate at all volume fractions on garnet and Al2O3 abrasives. Abrasion on SiC resulted in a minimum of the wear rate for the composite with 20% TiB2for most conditions. The composite with 40% TiB2consistently exhibited wear rates higher than the other composites when abraded on SiC. The only instance when the NiAl?40% TiB2 composite had a lower wear rate was when it was abraded on 16 and 37 mm SiC particles. The NiAl?TiB2 composite serves as a model system for studying the effect of reinforcement volume fraction on composite wear behavior and is discussed in terms of a composite wear model developed by Axe?n and Jacobson. q1999 Published by Elsevier Science S.A. All rights reserved.

Hawk, Jeffrey A.; Alman, David E.

1999-04-01

345

Thermodynamics on hydride vapor phase epitaxy of AlN using AlCl3 and NH3  

NASA Astrophysics Data System (ADS)

A thermodynamic analysis on hydride vapor phase epitaxy (HVPE) of AlN using AlCl3 and NH3 was performed. Regardless of the carrier gas used, partial pressures of Al-containing gaseous species [AlCl3, AlCl2, AlCl and (AlCl3)2] in equilibrium with AlN are significantly low in the temperature range of 500-1500 °C when the input V/III ratio is above 1. This means that the driving force for AlN growth (?PAl) becomes almost equal to the input partial pressure of AlCl3, which is quite different from HVPE of GaN. The good agreement between the calculated and experimental growth rates shows that HVPE of AlN is thermodynamically controlled.

Kumagai, Y.; Takemoto, K.; Kikuchi, J.; Hasegawa, T.; Murakami, H.; Koukitu, A.

346

Structure of vapor-phase deposited Al-Ge thin films and Al-Ge intermediate layer bonding of Al-based microchannel structures.  

SciTech Connect

Al-based high-aspect-ratio microscale structures (HARMS) are basic building blocks for all-Al microdevices. Bonding of Al-based HARMS is essential for device assembly. In this paper, bonding of Al-based HARMS to flat Al plates using Al-Ge thin film intermediate layers is investigated. The structure of sputter codeposited Al-Ge thin films was studied by high-resolution transmission electron microscopy as a function of the average film composition. The structure of the interface region between Al-based HARMS bonded to flat Al plates is studied by combining focused ion beam sectioning and scanning electron microscopy. An extended bonding interface region, {approx}100 {micro}m in width, is observed and suggested to result from liquidus/solidus reactions as well as diffusion of Ge in solid Al at the bonding temperature of 500 C. The extended interface region is suggested to be beneficial to Al-Al bonding via Al-Ge intermediate layers.

Mei, F. H.; Meng, W. J.; Hiller, J.; Miller, D. J.; Materials Science Division; Louisana State Univ.

2009-02-01

347

The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors  

NASA Astrophysics Data System (ADS)

The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors is reported. After treatment of the devices by annealing processes in forming gas atmosphere at different temperatures and for different times, distinct and reproducible changes of their resistance and capacitance values were found. According to the temperature regime, we observed different behaviors with regard to the resistance changes, namely the tendency to decrease the resistance by annealing at T=200 °C, but to increase the resistance by annealing at T=400 °C. We attribute this behavior to changes in the aluminum oxide barriers of the tunnel junctions. The good reproducibility of these effects with respect to the changes observed allows the proper annealing treatment to be used for postprocess tuning of tunnel junction parameters. Also, the influence of the annealing treatment on the noise properties of the transistors at low frequency was investigated. In no case did the noise figures in the 1/f regime show significant changes.

Scherer, H.; Weimann, Th.; Zorin, A. B.; Niemeyer, J.

2001-09-01

348

The embrittlement of Al-Zn-Mg and Al-Mg alloys by water vapor  

Microsoft Academic Search

Al4.5Zn1.5Mg and Al5Mg were reacted in water-vapor saturated air (WVSA) at 120?C and tensile tested. After an initial loss\\u000a of ductility with exposure time, probably caused by hydrogen embrittlement of the grain boundaries, between 15 hours and 25\\u000a hours exposure the mechanical properties of Al4.5Zn1.5Mg improved, this effect being due both to a reduced corrosion activity\\u000a of the grain boundaries

C. D. S. Tuck

1985-01-01

349

A crystalline oxide passivation for Al2O3/AlGaN/GaN  

NASA Astrophysics Data System (ADS)

In situ X-ray photoelectron spectroscopy and low energy electron diffraction are performed to study the formation of a crystalline oxide on the AlGaN surface. The oxidation of the AlGaN surface is prepared by annealing and remote N2 + O2 plasma pretreatments resulting in a stable crystalline oxide. The impact of the oxide on the interface state density is studied by capacitance voltage (C-V) measurements. It is found that a remote plasma exposure at 550 °C shows the smallest frequency dispersion. Crystalline oxide formation may provide a novel passivation method for high quality AlGaN/GaN devices.

Qin, Xiaoye; Dong, Hong; Kim, Jiyoung; Wallace, Robert M.

2014-10-01

350

When Validity Testing Lacks Validity: Comment on Levine et al.  

ERIC Educational Resources Information Center

Addresses each of the three main areas of Levine et al.'s (see this issue, CS 764 297) validity testing: mean differences in self-construals between Asians and Westerners and within individuals; priming experiments; and factor analysis of self-construal scales. Suggests that Levine et al.'s conclusions on crucial aspects of validity are untenable.…

Kim, Min-Sun; Raja, Narayan S.

2003-01-01

351

Precipitation mechanism of Al-substituted tobermorite using hydrothermal reaction  

NASA Astrophysics Data System (ADS)

We examined the addition of different crystal phases of alumina (?-Al2O3, ?-Al2O3) to slurries consisting of quartz and slaked lime for synthesis of Al-substituted tobermorite. XRD results showed that Al-substituted tobermorite formed after the reaction. It was clear that two kinds of Al-substituted tobermorite synthesized using different alumina crystal phases shows different morphologies. The difference in the reactivity of the Al2O3 had an influence in the hydrothermal reaction environment. The coordination number and chemical bonding-state of Al caused the different morphology of the tobermorite.

Abe, Kazuki; Maeda, Hirotaka; Ishida, Emile H.

2010-11-01

352

Post9\\/11 Evolution of Al Qaeda  

Microsoft Academic Search

\\u000a Before the 11 September 2001 attacks, Al-Qaeda had conducted an average of one attack every two years. Since then, Al-Qaeda\\u000a and its associated groups – what could be termed the Al-Qaeda movement – have mounted an attack, on average, every three months.\\u000a US successes in disrupting the Al-Qaeda network have also dispersed its operatives. Al-Qaeda organizers, operatives, financiers\\u000a and other

Rohan Kumar Gunaratna

2004-01-01

353

Enthalpies of formation of the Al–Ni intermetallic compounds  

Microsoft Academic Search

The Al–Ni system has been investigated by direct reaction calorimetry at high temperatures. Enthalpies of formation of the intermetallic compounds AlNi3, AlNi, Al3Ni2, and Al3Ni were determined and compared with the available experimental values based on calorimetric and emf measurements and with the calculated values from theoretical models. X-ray powder diffraction (XRD) and electron probe microanalysis (EPMA) were used to

F. Z Chrifi-Alaoui; M Nassik; K Mahdouk; J. C Gachon

2004-01-01

354

Stress evolution during ultrasonic Al ribbon bonding  

NASA Astrophysics Data System (ADS)

The present study reveals the stress distribution in the substrate during ultrasonic bonding. The deformations of the Si substrate, Al ribbon, and Al pad were numerically analyzed using a finite element method. Experimental observation of the interface using a highspeed video camera was also conducted to determine the actual interfacial slip amplitude. This amplitude becomes smaller than that of tool-tip with bonding time. It was suggested from the numerical simulations that frictional adhesion enhanced the friction force, resulting in an increase in the equivalent stress in the ribbon and pad. As a result, very large stresses occur in the substrate during ultrasonic bonding. These stresses evolve with the progress of ultrasonic bonding, i.e., frictional adhesion.

Ando, Masaya; Takashima, Kazumasa; Maeda, Masakatsu; Takahashi, Yasuo

2014-08-01

355

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

356

Polarized Cold Neutron Capture in ^27Al  

NASA Astrophysics Data System (ADS)

The NPDGamma Experiment at the Spallation Neutron Source at ORNL is measuring the parity-odd correlation between the neutron spin and the direction of the emitted photon in the capture of cold neutrons on a 16-liter liquid parahydrogen target. The goal is to determine the strength of the weak nucleon-nucleon interaction. One of the main background contributions comes from the gamma rays produced by neutrons captured in the Al walls of the target vessel. To quantify this effect a commissioning experiment measured the parity-odd and parity-even asymmetries in the angular distribution of the gamma rays from the capture of polarized cold neutrons in a solid Al target. A status of the analysis of this experiment will be presented.

Balascuta, Septimiu

2013-04-01

357

Structure analysis of NiAl martensite  

SciTech Connect

Neutron elastic scattering experiments were performed in order to investigate the structure of the low temperature martensitic phase of Ni/sub 62.5/Al/sub 37.5/ alloy. The average structure analyzed from the integrated intensity was approximately described by the (5,/minus/2) structure proposed by Martynov et al. Small deviation from the exact (5,/minus/2) model in the positional parameters and the anomalously large Debye-Waller factor were obtained. The observed satellite profiles show asymmetrical broadening, and the peak positions shift from the regular reciprocal lattice points. These anomalous features of scattering profiles were tentatively interpreted by introducing spatial modulation of the strain and order parameters. 12 refs., 2 figs., 1 tab.

Noda, Y.; Shapiro, S.M.; Shirane, G.; Yamada, Y.; Fuchizaki, K.; Tanner, L.E.

1989-01-01

358

Berkeley Lab's ALS generates Femtosecond Synchrotron Radiation  

SciTech Connect

A Lawrence Berkeley National Laboratory (Berkeley Lab) team drawing its members from the Materials Sciences Division (MSD), the Center for Beam Physics in the Accelerator and Fusion Research Division, and the Advanced Light Source (ALS) has succeeded in generating 300-femtosecond pulses of synchrotron radiation at the ALS synchrotron radiation machine. Though this ''proof-of-principle'' experiment made use of visible light on a borrowed beamline, the laser ''time-slicing'' technique at the heart of the demonstration will soon be applied in a new bend-magnet beamline designed explicitly for the production of femtosecond pulses of X-rays to study long-range and local order in condensed matter with ultrafast time resolution. An undulator beamline based on the same technique has been proposed that will dramatically increase the flux and brightness.

Robinson, Arthur L.

2000-05-23

359

Self-aligned contact process for Nb/Al-AlO(x)/Nb Josephson junctions  

NASA Astrophysics Data System (ADS)

High quality Nb/Al-AlO(x)/Nb Josephson junctions have been fabricated by a novel process named the self-aligned contact process. After the definition of the junction area by a reactive ion etching (RIE) technique, the exposed Nb layer and the junction edge are anodized to protect against electrical shorts and an Al film is deposited as the etching stopper layer. After base electrode patterning by RIE, an insulation layer is deposited. The contact hole, with the diameter of the junction, for connecting a counter electrode and a wiring layer, can be made without registration because of the deposited Al film. The junctions fabricated by this process have exhibited excellent current-voltage characteristics (Vm = 70 mV at the critical current density of 1.8 kA/sq cm, Vm = 11 mV at the critical current density of 20 kA/sq cm.

Morohashi, S.; Hasuo, S.; Yamaoka, T.

1986-01-01

360

Rechargeable Al/Cl2 battery with molten AlCl4/-/ electrolyte.  

NASA Technical Reports Server (NTRS)

A molten salt system based on Al- and Cl2 carbon electrodes, with an AlCl3 alkali chloride eutectic as electrolyte, offers promise as a rechargeable, high energy density battery which can operate at a relatively low temperature. Electrode kinetic studies showed that the electrode reactions at the Al anode were rapid and that the observed passivation phenomena were due to the formation at the electrode surface of a solid salt layer resulting from concentration changes on anodic or cathodic current flow. It was established that carbon electrodes were intrinsically active for chlorine reduction in AlCl3-alkali chloride melts. By means of a rotating vitreous carbon disk electrode, the kinetic parameters were determined.

Holleck, G. L.; Giner, J.; Burrows, B.

1972-01-01

361

The evolution of Al-Azhar Street, Al-Qahira, Egypt  

E-print Network

The historic quarter of Cairo, al-Qahira, is going through a period intense transformation that is threatening the physical environment as well as the social and economic fabric of the city. The transformations taking place ...

Elkatsha, Markus Fawzy Fahmy

2000-01-01

362

Fabrication and properties of functionally graded NiAl/Al2O3 composites  

NASA Technical Reports Server (NTRS)

A modified sedimentation process was used in the production of a functionally gradient material (FGM), NiAl/Al2O3. A simple finite element model was used to guide our design and fabrication efforts by estimating residual stress states as a function of composite structure. This approach could lead to tailored designs that enhance or avoid specific residual stress states. Thermal cycling tests were factored into the model to predict time dependent or steady-state internal temperature and stress profiles. Four-point bend tests were conducted to establish the mechanical load-displacement behavior of a single interlayer FGM at room temperature, 800 and 1000 K. Room temperature bend strength of the FGM was 3-4 times that of the base NiAl. At elevated temperatures, composite fracture occurred in a gradual, noncatastrophic mode involving NiAl retardation of a succession of cracks originating in the alumina face.

Miller, D. P.; Lannutti, J. J.; Noebe, R. D.

1993-01-01

363

Fabrication of Fe-Al nanoparticles by selective oxidation of Fe-Al thin films  

PubMed Central

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. PMID:23547781

2013-01-01

364

Synthesis and characterization of Al-Zn/Al2O3 nano-powder composites.  

PubMed

Composites consisting of Al-Zn/Al2O3 have been synthesized using high energy mechanical milling. High energy ball milling increases the sintering rate of the composite powder due to increased diffusion rate. Owing to the finer microstructure, the hardness of the sintered composite produced by using the mechanically milled nanocomposite powder is significantly higher than that of the sintered composite produced by using the as-mixed powder. The mean crystallite size of the matrix has been determined to be 27 nm by Scherrer equation using X-ray diffraction data. The powders have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and differential thermal analysis (DTA). The effect of high-energy ball milling and subsequent annealing on a mixture of Al and ZnO has also been investigated. DTA result show that the reaction temperature of Al-ZnO decreases with the increase in the ball milling time. PMID:17654976

Durai, T G; Das, Karabi; Das, Siddhartha

2007-06-01

365

Iron implantation in ?-Al2O3  

Microsoft Academic Search

Single crystal and ceramic ?-Al2O3 samples were implanted with 57Fe ions at different fluences, and different charge states of Fe were determined. The hyperfine interaction data showed that implanted ions are in Fe0, Fe2+, and Fe3+ states depending on the fluence. It is shown that after the annealing of the implanted sample in a 2.5CO 1CO2 atmosphere Fe spinel forms.

I. De´zsi; Cs. Fetzer

2008-01-01

366

this present b. He will als  

E-print Network

Room 00 PM3:0 efreshmen 2012 UMa THEMY T bstract: this present b. He will als cus on glo termediarie in lobal suppl he utilizes nmaking,g nal of Opera nalofProdu B,theJourna tScience,an ateProfesso Managem mization.Dr. l Research ernationalJ n,Mathema e. cholarin r of the nagement In2010, University Business

Nagurney, Anna

367

Al-ba?r al-mu??? war?? al-samaw?t wa-al-ar?: Jewish and Christian cosmogonic beliefs in early Islam  

Microsoft Academic Search

The aim of the present article is to analyse the assimilation of a series of ancient Semitic cosmogonic ideas by Islam via Judaism and Christianity, especially through the Aramaic-Arabic influence of the Syriac and Christian Arabic authors. The study focuses on a defective Hadith transmitted by the Andalus? traditionalist ?Abd al-Malik ibn ?ab?b (d. 852), which presents an old cosmogonic

Juan Pedro Monferrer-Sala

2011-01-01

368

Blausäuregas als bekämpfendes Holzschutzmittel für Kunstobjekte  

Microsoft Academic Search

Zusammenfassung  Durch Zyklon B hervorgerufene Schden an Tnungen und Malereien in der Pfarrkirche Untergriesbach bei Passau, die einige Monate vor der\\u000a Begasung restauriert worden war, wurden untersucht. Als Folge hoher relativer Luftfeuchtigkeit, bedingt durch heftigen Regen,\\u000a der whrend der Begasung einsetzte, bildete sich Schwitzwasser auf dem noch nicht karbonatisierten Kalkanstrich. In diesem\\u000a Wasser lste sich das Blausuregas, das unter Einflu des

D. Grosser; E. Roßmann

1974-01-01

369

Letters Regarding Article by Nasir et al, \\  

Microsoft Academic Search

We read with interest the article by Nasir et al1 that emphasizes the role of 12-lead ECG in the diagnosis of arrhythmogenic right ventricular cardiomyopathy\\/dysplasia (ARVC\\/D). The authors examined the ECG parameters in 50 affected patients, finding that almost all presented abnormal features and proposed as a new diagnostic ECG marker of ARVC a prolonged S-wave upstroke in V1 through

Willem Dewilde; Yves Vandekerckhove; Alexander Bol

370

The plastic deformation of TiAl  

Microsoft Academic Search

The deformation substructure of TiAl (Llo type ordered lattice) tested in compression, and the factors determining it were\\u000a investigated. Two types of dislocations take part in the plas-tic deformation, namely a\\/2 [110] and a\\/2 [Oil]. The latter\\u000a type will disorder the Llo super-lattice and therefore would be expected to move in pairs as superdislocations. Some obser-vations\\u000a are essentially in agreement

D. Shechtman; M. J. Blackburn; H. A. Lipsitt

1974-01-01

371

United States Patent [19] Burt et al.  

E-print Network

United States Patent [19] Burt et al. [11] Patent Number: 4 , 6 98, 84 3 [45] Date of Patent: Oct, 43, 49, 50, 54, 55 [56] References Cited U.S. PATENT DOCUMENTS 3,737,855 6/1973 Cutaia.S. Patent Oct. 6, 1987 Sheet 1 of 3 4,698,843 #12;U.S. Patent Oct. 6, 1987 Sheet 2 of 3 4,698,843 #12;U

Adelson, Edward

372

AlGaAs semiconductor laser illuminator  

Microsoft Academic Search

This program was directed at development of an acoustically covert, non-cryogenically cooled AlGaAs Semiconductor Laser Illuminator compatible with night vision equipment. The arraying approach undertaken for development used micro-cylindrical lenses attached to the face of the laser diodes and imaging the 2.5 micron junction. A conventionally drawn glass fiber was used for this lens. A solid glass integrator with a

W. W. Barratt; E. C. Lea; L. S. Ohara

1974-01-01

373

Euklid als Physiker: Die Realgeltung der Geometrie  

NASA Astrophysics Data System (ADS)

Es lässt sich beweisen, dass die Winkelsumme in einem ebenen, euklidischen Dreieck 180 Grad beträgt. Ebenso ergibt sich, dass die Winkelsumme in einem Dreieck auf einer Kugeloberfläche größer als 180 Grad ist. Auch der Satz des Pythagoras ist beweisbar. In allen Fällen beruhen die Beweise auf Euklids Parallelenaxiom. Das aber lässt sich nicht beweisen. Beweisbar aber ist, dass es in nicht-euklidischen Geomerien nicht gilt.

Genz, Henning

374

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

375

A secondary analyses of Bradac et al.'s prototype process-monitoring experiment  

Microsoft Academic Search

We report on the secondary analyses of some conjectures and empirical evidence presented in Bradac et al.'s prototype process-monitoring experiment, published previously in IEEE Transactions on Software Engineering . We identify 13 conjectures in the original paper, and re-analyse six of these conjectures using the original evidence. Rather than rejecting any of the original conjectures, we identify assumptions underlying those

Austen Rainer

376

Mechanical properties of an Al\\/Mg\\/Al trilaminated composite fabricated by hot rolling  

Microsoft Academic Search

An Al\\/Mg\\/Al composite with a trilaminate structure was fabricated by hot rolling and its mechanical properties at quasi-static\\u000a rates of strain were investigated. The bonding strength of the trilaminated composite is about 40 MPa, mainly attributing\\u000a to the mechanical bond at the interfaces. The first layer failure strength of the laminated composite increases from 305 to\\u000a 372 MPa when the relative thickness

X. P. ZhangT; T. H. Yang; J. Q. Liu; X. F. Luo; J. T. Wang

2010-01-01

377

An overview of monolithic titanium aluminides based on Ti 3Al and TiAl  

Microsoft Academic Search

Titanium aluminides based on TiAl and Ti3Al are emerging as a revolutionary high temperature material. In order to confer these materials the thermomechanical properties required for industrial applications, two-phase alloys are developed by microalloying. That leads to formulate different alloy compositions adapted to the fabrication process and to the specific properties required for engineering applications. Knowledge of the fundamental understanding

S Djanarthany; J.-C Viala; J Bouix

2001-01-01

378

The influence of second phase Ti3Al on the deformation mechanisms in TiAl  

Microsoft Academic Search

Dislocations in samples of a heat-treated and quenched two phase Ti-46at.% Al alloy have been characterized, and those with Burgers vectors, b, given by b=½<1l0] and b=½<112] have been observed. The microstructure of deformed samples is characterized mainly by dislocations with b=½<1l0]. These dislocations have high Peierls stresses in TiAl of nominal purity, because of the directionality of bonds between

V. K. Vasudevan; M. A. Stucke; S. A. Court; H. L. Fraser

1989-01-01

379

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

380

Tunneling properties of barriers in Nb\\/Al\\/AlOx\\/Nb junctions  

Microsoft Academic Search

We have measured DC I-V curves of niobium-trilayer (Nb\\/Al\\/AlOx\\/Nb) junctions with barriers thermally grown within a broad range of oxygen exposure E=Pt, from 2×105 to 2×109 Pa-s, and for applied electric fields ranging from zero all the way up to the breakdown - typically, above 10 MV\\/cm. The data can be reasonably well fitted by the direct theory assuming trapezoidal

S. K. Tolpygo; E. Cimpoiasu; X. Liu; N. Simonian; Yu. A. Polyakov; J. E. Lukens; K. K. Likharev

2003-01-01

381

Energetic ion bombarded Fe/Al multilayers  

SciTech Connect

The utility of ion-assisted deposition is investigated to explore the possibility of counteracting the deficiency of back-reflected current of Ar neutrals in the case of lighter elements such as Al. A range of energetically ion bombarded Fe/Al multilayers sputtered with applied surface bias of 0, -200, or -400 V were deposited onto Si(111) substrates in an argon atmosphere of 4 mTorr using a computer controlled dc magnetron sputtering system. Grazing incidence reflectivity and rocking curve scans by synchrotron x rays of wavelength of 1.38 A were used to investigate the structures of the interfaces produced. Substantial evidence has been gathered to suggest the gradual suppression of interfacial mixing and reduction in interfacial roughness with increases of applied bias. The densification of the Al microstructure was noticeable and may be a consequence of resputtering attributable to the induced ion bombardment. The average interfacial roughnesses were calculated for the 0, -200, and -400 V samples to be 7{+-}0.5, 6{+-}0.5, and 5{+-}0.5 A respectfully demonstrating a 30% improvement in interface quality. Data from rocking curve scans point to improved long-range correlated roughness in energetically deposited samples. The computational code based on the recursive algorithm developed by Parratt [Phys. Rev. 95, 359 (1954)] was successful in the simulation of the specular reflectivity curves.

Al-Busaidy, M.S.; Crapper, M.D. [College Science, Physics Department, Sultan Qaboos University, P.O. Box 36, Al-Khod 123 (Oman); Department of Physics, Loughborough University, Loughborough (United Kingdom)

2006-05-15

382

Liquid metal corrosion of 316L, Fe 3 Al, and FeCrSi in molten Zn-Al baths  

Microsoft Academic Search

Corrosion tests of 316L and two intermetallic compounds Fe3Al and FeCrSi in industrial Galvanizing (Zn-0.18Al), GALFAN (Zn-5Al), GALVALUME (Zn-55Al), and Aluminizing (Al-8Si) baths\\u000a and lab-scale static baths were conducted. In on-line tests in industrial hot-dip baths, 316L steel shows better corrosion\\u000a resistance than Fe3Al in Galvanizing, GALFAN, and GALVALUME baths. The corrosion resistance of 316L and Fe3Al is similar in

Xingbo Liu; Ever Barbero; Jing Xu; Matthew Burris; Keh-Minn Chang; Vinod Sikka

2005-01-01

383

Internal photoemission in Ag-Al2O3-Al junctions  

NASA Technical Reports Server (NTRS)

The magnitude of the photon-induced current in Ag-Al2O3-Al metal-oxide-metal junctions has been studied as a function of photon energy and angle of incident radiation. Photocurrents were theoretically analyzed on the basis of a modified vacuum photoemission model (Jain, 1975; Slayman et al., to be published). Optical constants previously reported in the literature (Irani et al., 1971; Ehnrereich et al., 1963) were used to calculate the true spatial generation rate in Ag and Al as a function of the angle, polarization of incident radiation, and film thickness. Results were found to be in very good agreement with experimentally determined values for a tunable dye laser with a KDP doubling crystal pumped by a Q-switched Nd:YAG laser with a LiIO3 doubling crystal. The system provided risetimes of 50 ns or less and peak powers of 10 W. Under short circuit conditions, the photoresponse to incident power was linear up to available power densities of 10 kW/sq cm. Quantum efficiencies of about 0.1% at zero-bias, near 3.8 eV under P polarization, were typically observed.

Guedes, J. M. P.; Slayman, C. W.; Gustafson, T. K.; Jain, R. K.

1979-01-01

384

The protective coatings of NdFeB magnets by Al and Al(Fe)  

SciTech Connect

NdFeB permanent magnets are coated by two different methods, dip coating and evaporation coating, with Al. It is found that an intermetallic reaction has occurred and formed a dominant phase of FeAl{sub 2.5}B{sub {ital x}} at the interface between the Al coating and the magnet material. Such reaction enhances strong bonding between the coating and the magnet. When Al(Fe) is used for the coating, no detectable intermetallic phase is observed, and therefore the amount of magnet material is conserved. We have studied the effect of the intermetallic phase on corrosion protection of the magnet. It is found that this phase is less resistive towards HNO{sub 3} solution than pure Al; but it is more resistive towards NaOH and NaCl. The investigation of the changes of microstructures of the coatings under different tempering conditions have also been carried out. The results show that the heat treatment at 500{degree}C for 10 min for a {approximately} 2 {mu}m thick Al coating by evaporation can produce an optimal layer of intermetallics. If the temperature is too low, the coating will not adhere to the magnet or if too high, it will fully react with the magnet and produce a rough coating surface. {copyright} {ital 1996 American Institute of Physics.}

Qin, C.; Li, A.S.; Ng, D.H. [Department of Physics, The Chinese University of Hong Kong, Shatin (Hong Kong)] [Department of Physics, The Chinese University of Hong Kong, Shatin (Hong Kong)

1996-04-01

385

Air Blast Characteristics for Laminate Al and Al-Ni Composites  

NASA Astrophysics Data System (ADS)

Air blast characteristics of laminate Al and Al-Ni composites were investigated in a 23 m^3 closed chamber. 50 to 100 ?m thick Al-Ni or Al foils were rolled to form a cylindrical shell, which was then compacted to a density larger than 99% TMD through an explosive formation technique. Charges were prepared using 2 kg C4 explosive packed in the laminate metal shell to a metal-explosive mass ratio of 1.75. Pressure and temperature were measured through transducers on the chamber wall and pyrometry sensors facing the charge center. The pressure history showed a double-shock front structure with an accelerating precursor shock of high amplitude followed by the primary blast, suggesting considerable early-time reaction of small laminate fragments. Significant enhanced explosion pressure (QSP) was observed as compared with baseline charges in solid shell. Recovered residue showed fragments in flakes with a considerable fraction in the molten. The pressure and temperature results are further analyzed to distinguish the reaction properties between the Al-Ni (gasless reaction for them alone) and Al laminates as well as their effect on air blast. The results are also compared with previous investigations using various shell materials and compositing techniques.

Zhang, Fan

2011-06-01

386

Redistribution of Ti and Al in deuterium charged TiAl  

NASA Technical Reports Server (NTRS)

The redistribution of titanium and aluminum in a single-phase TiAl alloy that has been exposed to a high pressure of deuterium gas at high temperature is studied. The microstructure in the as-received, uncharged condition consisted of single-phase gamma TiAl grains and a random distribution of precipitates. Precipitates were distributed throughout the matrix and along the grain boundaries. The chemistry of the precipitates varied considerably; some were rich in Al, while other were mostly Ti with some Si and Al. The dislocation density in most grains was low, although in a few grains a high dislocation density was observed. FCC deuterides with a lattice parameter of 0.45 nm form in a Ti-52.1Al-2.1Ta (at. pct) alloy after exposure to 1.38 MPa of deuterium gas at 650 C for 213 hr. The structure and lattice parameter are consistent with the formation of Ti(l)D2. The deuterides that form in this alloy are enriched in Ti and deficient in Al and Ta compared to the deuteride-free matrix. Regions of the matrix contiguous with the deuterides have a correspondingly enhanced aluminum and tantalum concentration.

Legzdina, D.; Robertson, I. M.; Birnbaum, H. K.

1992-01-01

387

Room Temperature Radiolytic Synthesized Cu@CuAlO(2)-Al(2)O(3) Nanoparticles.  

PubMed

Colloidal Cu@CuAlO(2)-Al(2)O(3) bimetallic nanoparticles were prepared by a gamma irradiation method in an aqueous system in the presence of polyvinyl pyrrolidone (PVP) and isopropanol respectively as a colloidal stabilizer and scavenger of hydrogen and hydroxyl radicals. The gamma irradiation was carried out in a (60)Co gamma source chamber with different doses up to 120 kGy. The formation of Cu@CuAlO(2)-Al(2)O(3) nanoparticles was observed initially by the change in color of the colloidal samples from colorless to brown. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of bonds between polymer chains and the metal surface at all radiation doses. Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO(2)-Al(2)O(3) nanoparticles are in a core-shell structure. By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained. The average particle diameter increased with increased precursor concentration and decreased with increased dose. This is due to the competition between nucleation, growth, and aggregation processes in the formation of nanoclusters during irradiation. PMID:23109893

Abedini, Alam; Saion, Elias; Larki, Farhad; Zakaria, Azmi; Noroozi, Monir; Soltani, Nayereh

2012-01-01

388

FeAl and NbAl3 Intermetallic-HVOF Coatings: Structure and Properties  

NASA Astrophysics Data System (ADS)

Transition metal aluminides in their coating form are currently being explored in terms of resistance to oxidation and mechanical behavior. This interest in transition metal aluminides is mainly due to the fact that their high Al content makes them attractive for high-temperature applications. This is also a reason to study their resistance to wear; they may be suitable for use in applications that produce a lot of wear in aggressive environments, thus replacing established coating materials. In this study, the microstructure, microhardness, and wear and oxidation performance of FeAl and NbAl3 coatings produced by high-velocity oxy-fuel spraying are evaluated with two main aims: (i) to compare these two coating systems—a commonly studied aluminide (FeAl) and, NbAl3, an aluminide whose deposition by thermal spraying has not been attempted to date—and (ii) to analyze the relationship between their microstructure, composition and properties, and so clarify their wear and oxidation mechanisms. In the present study, the higher hardness of niobium aluminide coatings did not correlate with a higher wear resistance and, finally, although pesting phenomena (disintegration in oxidizing environments) were already known of in bulk niobium aluminides, here their behavior in the coating form is examined. It was shown that such accelerated oxidation was inevitable with respect to the better resistance of FeAl, but further improvements are foreseen by addition of alloying elements in that alloy.

Guilemany, J. M.; Cinca, N.; Dosta, S.; Cano, I. G.

2009-12-01

389

Study on the hydrolysis/precipitation behavior of Keggin Al13 and Al30 polymers in polyaluminum solutions.  

PubMed

The hydrolysis/precipitation behaviors of Al(3+), Al(13) and Al(30) under conditions typical for flocculation in water treatment were investigated by studying the particulates' size development, charge characteristics, chemical species and speciation transformation of coagulant hydrolysis precipitates. The optimal pH conditions for hydrolysis precipitates formation for AlCl(3), PAC(Al13) and PAC(Al30) were 6.5-7.5, 8.5-9.5, and 7.5-9.5, respectively. The precipitates' formation rate increased with the increase in dosage, and the relative rates were AlCl(3)>PAC(Al30)>PAC(Al13). The precipitates' size increased when the dosage increased from 50 microM to 200 microM, but it decreased when the dosage increased to 800 microM. The Zeta potential of coagulant hydrolysis precipitates decreased with the increase in pH for the three coagulants. The iso-electric points of the freshly formed precipitates for AlCl(3), PAC(Al13) and PAC(Al30) were 7.3, 9.6 and 9.2, respectively. The Zeta potentials of AlCl(3) hydrolysis precipitates were lower than those of PAC(Al13) and PAC(Al30) when pH>5.0. The Zeta potential of PAC(Al30) hydrolysis precipitates was higher than that of PAC(Al13) at the acidic side, but lower at the alkaline side. The dosage had no obvious effect on the Zeta potential of hydrolysis precipitates under fixed pH conditions. The increase in Zeta potential with the increase in dosage under uncontrolled pH conditions was due to the pH depression caused by coagulant addition. Al-Ferron research indicated that the hydrolysis precipitates of AlCl(3) were composed of amorphous Al(OH)(3) precipitates, but those of PAC(Al13) and PAC(Al30) were composed of aggregates of Al(13) and Al(30), respectively. Al(3+) was the most un-stable species in coagulants, and its hydrolysis was remarkably influenced by solution pH. Al(13) and Al(30) species were very stable, and solution pH and aging had little effect on the chemical species of their hydrolysis products. The research method involving coagulant hydrolysis precipitates based on Al-Ferron reaction kinetics was studied in detail. The Al species classification based on complex reaction kinetic of hydrolysis precipitates and Ferron reagent was different from that measured in a conventional coagulant assay using the Al-Ferron method. The chemical composition of Al(a), Al(b) and Al(c) depended on coagulant and solution pH. The Al(b) measured in the current case was different from Keggin Al(13), and the high Al(b) content in the AlCl(3) hydrolysis precipitates could not used as testimony that most of the Al(3+) was converted to highly charged Al(13) species during AlCl(3) coagulation. PMID:19409689

Chen, Zhaoyang; Luan, Zhaokun; Jia, Zhiping; Li, Xiaosen

2009-06-01

390

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

391

(5.5) BRAZING OF METALLIC-INTERMETALLIC LAMINATE (MIL) Ti-6Al-4V/Al3Ti COMPOSITES  

E-print Network

low density and high stiffness of Ti/Al3Ti based MIL composites compared to conventional monolithic) reported that electron beam welding of TiAl is possible, but that welding cracks cannot be avoided.86 TiAl3 20 Ti 0.20 Ti-6Al-4V and 0.80 TiAl3 In order to braze titanium materials, brazing fillers based

Meyers, Marc A.

392

High-efficiency AlGaN-based UV light-emitting diode on laterally overgrown AlN  

Microsoft Academic Search

Ultraviolet light-emitting diodes (UV-LEDs) with a peak wavelength of 335nm were fabricated on AlN\\/sapphire templates. As templates for the fabrication of UV-LEDs, planar AlN and epitaxial laterally overgrown (ELO) AlN on sapphire (0001) substrates were compared. The output power of UV-LEDs grown on ELO-AlN was 27 times higher than that of UV-LEDs on the planar AlN template.

Kentaro Nagamatsu; Narihito Okada; Hiroki Sugimura; Hirotoshi Tsuzuki; Fumiaki Mori; Kazuyoshi Iida; Akira Bando; Motoaki Iwaya; Satoshi Kamiyama; Hiroshi Amano; Isamu Akasaki

2008-01-01

393

Fabrication of high wear resistant Al\\/Al 3Ti metal matrix composite by in situ hot press method  

Microsoft Academic Search

In this study, hot press method has been used to fabricate Al\\/Al3Ti composite. In situ reacted Al3Ti compound is formed through Al and TiO2 powder blend in order to enhance mechanical properties and mainly wear resistance. After homogeneous blending of Al and TiO2, hot pressing was performed at 580°C at different durations and pressures. Scanning electron microscopy was used for

M. Nofar; H. R. Madaah Hosseini; N. Kolagar-Daroonkolaie

2009-01-01

394

Solidification Behavior of gamma'-Ni3Al Containing Alloys in the Ni-Al-O System  

NASA Technical Reports Server (NTRS)

The chemical activities of Al and Ni in gamma(prime)-Ni3Al-containing systems were measured using the multi-cell Knudsen effusion-cell mass spectrometry technique (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K. From these measurements a better understanding of the equilibrium solidification behaviour of gamma(prime)-Ni3Al-containing alloys in the Ni-Al-O system was established. Specifically, these measurements revealed that (1) gamma(prime)-Ni3Al forms via the peritectiod reaction, gamma + Beta (+ A12O3) = gamma (prime) (+ Al2O3), at 1633 +/- 1 K, (2) the {gamma + Beta + Al2O3} phase field is stable over the temperature range 1633 through 1640 K, and (3) equilibrium solidification occurs by the eutectic reaction, L (+ Al2O3) = gamma + Beta (+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%Al (at an unknown oxygen content). When projected onto the Ni-Al binary, this behaviour is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(prime)-Ni3Al phase field.

Copland, Evan

2007-01-01

395

Creep and Toughness of Cryomilled NiAl Containing Cr  

NASA Technical Reports Server (NTRS)

NiAl-AlN + Cr composites were produced by blending cryomilled NiAl powder with approx. 10 vol % Cr flakes. In comparison to the as-consolidated matrices, hot isostatically pressed Cr-modified materials did not demonstrate any significant improvement in toughness. Hot extruded NiAl-AlN+10.5Cr, however, possessed a toughness twice that determine for the base NiAl-AlN alloy. Measurement of the 1200 to 1400 K plastic flow properties revealed that the strength of the composites was completely controlled by the properties of the NiAl-AlN matrices. This behavior could be successfully modeled by the Rule-of-Mixtures, where load is shed from the weak Cr to the strong matrix.

Whittenberger, J. Daniel; Aikin, Beverly; Salem, Jon

2000-01-01

396

Computational study of OCN- chemisorption over AlN nanostructures  

NASA Astrophysics Data System (ADS)

Density functional theory (DFT) calculations were applied to consider the adsorption of cyanato anion (OCN-) on the external surfaces of AlN nanotubes and AlN nano-cages. The interaction energies of OCN- (N-side) interacted with (6, 0) and (4, 4) AlN nanotubes are about -2.84 and -2.72 eV, respectively, implying that the pristine (6, 0) AlN nanotubes is more reactive and sensitive than (4, 4) AlN nanotubes for OCN- detection. The adsorption energy of the reaction between OCN- and Al16N16 is too strong (-3.32 eV) than that of Al12N12 (-3.24 eV). The results demonstrate that the AlN nano-cages have a better condition for practical applications as a chemical adsorbent for the adsorption of OCN- compared with AlN nanotubes.

Baei, Mohammad T.; Taghartapeh, Mohammad Ramezani; Lemeski, E. Tazikeh; Soltani, Alireza

2014-08-01

397

Gaussian density-functional study for small neutral (Al n ), positive (Al{/n +}) and negative (Al{/n -}) aluminium clusters ( n=2 5)  

NASA Astrophysics Data System (ADS)

The structures and properties of Al n , Al{/n +}, Al{/n -} ( n=1,5) clusters have been investigated by using the Linear Combination of Gaussian Type Orbitals (LCGTO) method, considering Local (LSD) and Non Local (NLSD) Spin Density Approximations and employing a Model Core Potential (MCP) that allows the explicit treatment of 3 s 2 3 p 1 valence electrons. For each system different geometrical structures and electronic states have been considered. For Al3, Al{3/+}, Al{3/-} the most stable geometry proved to be the equilateral triangle ( D 3 h ). Al4 and Al{4/+} prefer the rhombus ( D 2 h ) structure, while the corresponding anion prefers the square ( D 4 h ) one. The trapezoidal form ( C 2 v ) is the most stable isomer for Al5, Al{5/+} and Al{5/-} clusters. The analysis of vibrational frequencies shows that these structures are minima in the potential energy surface. The binding energies ( D e), the adiabatic ionization potentials (IP) and electron affinities (EA), the chemical potentials or absolute hardnesses (?) and electronegativities (?) have been computed. Results are in good agreement with the available experimental data and the previous high level theoretical computations.

Calaminici, Patrizia; Russo, Nino; Toscano, Marirosa

1995-12-01

398

Alignment of the TiAl/Ti{sub 3}Al lamellar microstructure in TiAl alloys by growth from a seed material  

SciTech Connect

By using an appropriately oriented seed from the TiAl-Si system, the TiAl/Ti{sub 3}Al lamellar microstructure was aligned parallel to the growth direction in a number of directionally solidified TiAl-based alloys. The seed composition was kept constant at Ti-43Al-3Si (at.%) and the composition of the master ingots was varied for alloys in the TiAl-Si, TiAl-Nb-Si, and Ti-Al systems. The lamellar microstructure could be aligned for alloys containing up to approximately 47 at.% (Al + Si) in each of these systems. For the composition of seed material, Ti-43Al-3Si, where alpha is the primary solidification phase, the original orientation of the lamellar microstructure was maintained after heating to and cooling from the single-phase alpha region making seeding of the alpha phase possible. When this silicon containing seed was used, the nucleation of the primary beta phase in master alloys of Ti-(47 {minus} x)Al-xSi(x = 0 to 1 at.%) could be suppressed resulting in the nucleation and growth of only the alpha phase with an orientation determined by the seed crystal. After steady state conditions were reached, single PST crystals with an aligned lamellar microstructure could be grown at growth rates as high as 40 mm/h.

Johnson, D.R.; Masuda, Y.; Inui, H.; Yamaguchi, M. [Kyoto Univ. (Japan). Dept. of Materials Science and Engineering] [Kyoto Univ. (Japan). Dept. of Materials Science and Engineering

1997-06-01

399

Al-Ca and Al-Fe metal-metal composite strength, conductivity, and microstructure relationships  

SciTech Connect

Deformation processed metal-metal composites (DMMC’s) are composites formed by mechanical working (i.e., rolling, swaging, or wire drawing) of two-phase, ductile metal mixtures. Since both the matrix and reinforcing phase are ductile metals, the composites can be heavily deformed to reduce the thickness and spacing of the two phases. Recent studies have shown that heavily drawn DMMCs can achieve anomalously high strength and outstanding combinations of strength and conductivity. In this study, Al-Fe wire composite with 0.07, 0.1, and 0.2 volume fractions of Fe filaments and Al-Ca wire composite with 0.03, 0.06, and 0.09 volume fractions of Ca filaments were produced in situ, and their mechanical properties were measured as a function of deformation true strain. The Al-Fe composites displayed limited deformation of the Fe phase even at high true strains, resulting in little strengthening effect in those composites. Al-9vol%Ca wire was deformed to a deformation true strain of 13.76. The resulting Ca second-phase filaments were deformed to thicknesses on the order of one micrometer. The ultimate tensile strength increased exponentially with increasing deformation true strain, reaching a value of 197 MPa at a true strain of 13.76. This value is 2.5 times higher than the value predicted by the rule of mixtures. A quantitative relationship between UTS and deformation true strain was determined. X-ray diffraction data on transformation of Al + Ca microstructures to Al + various Al-Ca intermetallic compounds were obtained at the Advanced Photon Source at Argonne National Laboratory. Electrical conductivity was measured over a range of true strains and post-deformation heat treatment schedules.

Kim, Hyong June

2011-12-01

400

Electronic properties of AlGaAs and AlGaAs/GaAs heterostructures  

SciTech Connect

The electronic properties of free-standing Al/sub x/Ga/sub 1-x/As epitaxial layers and Al/sub x/Ga/sub 1-x/AsGaAs heterostructures are investigated. The fact that the persistent-photoconductivity (PPC) effect is a property Al/sub x/Ga/sub 1-x/As is established experimentally by observing the PPC effect in four free-standing Al/sub x/Ga/sub 1-x/As layers with alloy composition 0.26 less than or equal to x less than or equal to 0.32. The investigated samples were grown by LPE, MBE, and MOCVD. Experimental values of n/sub H/ and ..mu../sub H/ at room temperature for free-standing Al/sub x/Ga/sub 1-x/As layers are obtained. The author observed and investigated a new effect in Al/sub 0.3/Ga/sub 0.7/AsGaAs heterostructures that they called thermally stimulated persistent conductivity. After a heterostructure is cooled (53-55 min.) from room temperature to low temperatures (120 to 140K), the electron concentration and mobility do not stay constant with time. Electron concentration decreases slowly (days) while Hall mobility increases. This effect is attributed to the properties of the two-dimensional electron gas (2DEG) formed at the heterointerface. Investigation of the PPC effect in a heterostructure indicates that two mechanisms are responsible: at first, PPC due to the AlGaAs epitaxial layer is dominant, while at a later stage PPC due to the properties of the heterointerface dominates

Leybovich, I.S.

1986-01-01

401

Intermediate temperature thermomechanical processing of Al 2090 for superplasticity  

NASA Technical Reports Server (NTRS)

The Al-Cu-Li phase diagram indicates that during thermomechanical processing of Al 2090 at 300 C both T(1) and T(2) phases will precipitate. Following work on Al-Mg-X alloys, it is possible that TMP at such temperatures might promote intragranular formation of these phases and promote microstructural refinement during recrystallization. Microstructural analyses reveal that the T(2) phase in Al 2090 may play a similar role to the beta-phase in Al-Mg-X alloys during microstructural evolution. Mechanical property data indicate that Al 2090 can be moderately (215-245 percent) superplastic at 370 C following processing at 300 C.

Hales, S. J.; Mcnelley, T. R.; Groh, G. E.

1989-01-01

402

ALS 2883: Analysis of spectroscopic features  

NASA Astrophysics Data System (ADS)

ALS 2883 (RA 13^{h} 02^{m} 47^{s}, DEC -63^{o} 50' 08'', M_{v} 10.1) is the first known radio pulsar with an emission B-type companion system, discovered in 1992. The Be companion of ALS 2883 has all line profiles in the visible range in emission. This emission is a common hallmark among many Be stars, and this effect is thought to be due to the presence of a circumstellar environment. Also, the star is orbiting a X-ray source as has been detected by the XMM-Newton Science Operation Center. In this study, we present the observations of ALS 2883 made at the OPD/LNA 1.60 m telescope with the Coudé spectrograph in the range 4000 to 5000 Å and S/N simeq 200, performed in April 2011. First-order estimations of T_{eff} and log g parameters have been performed through Johnson's UBV and JHK photometric calibrations. Projected rotation velocity V sin i has been estimated through the mean of the first zeroes of the Fourier transforms of neutral helium rotation profiles adopting linear, quadratic and square-root limb-darkening laws. The physical conditions of the circumstellar envelope were estimated through the solution of the radiative transport equation assuming local thermodynamic equilibrium within a disk-shaped circumstellar environment with a Keplerian velocity field. The radiative transport equation is solved assuming the Roche model as a boundary condition in the circumstellar environment. Iterating the computations with a downhill-simplex algorithm, this analysis leads to a best solution for an envelope with T simeq 9500 K, gas density ? simeq 2 × 10^{-15} g.cm^{-3}, internal radius r_{i} simeq 8 R_{odot} and external radius r_e simeq 30 R_{odot}, rotating with V_{rot} simeq 140 km.s^{-1} and expanding with V_{exp} simeq 90 km.s^{-1}.

Silva, A. R.; Levenhagen, R. S.; Künzel, R.; Leister, N. V.

2014-10-01

403

ICP etching of high Al mole fraction AlGaN  

NASA Astrophysics Data System (ADS)

The etching process has great influence on the performance of solar blind detector based on AlxGa1-xN epitaxial layers on sapphire substrate with high Al mole fraction grown by metal organic chemical vapor deposition (MOCVD) method. Traditional etching methods, including wet or reactive ion etching (RIE) are hard to achieve good result due to the high chemical-stability of AlGaN films with high Al mole fraction. In this paper, we studied on the inductively coupled plasma reactive ion etching (ICP-RIE) of high Al mole fraction AlxGa1-xN films (x>0.4) for fabricating high performance solar blind detectors. SiN was used as mask, and Cl2 and BCl3 were used as etching gas. Etching systems was selected from Oxford Inc. DC bias was controlled automatically. A 2.5:1 of selectivity on AlGaN and SiN was obtained with suitable flux and component of etching gas, RF power and ICP power. Etching velocity was adjusted mainly by RF power. The role of Ar, Cl2, and BCl3 in the etching process was also discussed.

Meng, Zhao; Yu, Libo; Li, Xiao; Liu, Qibin; Duan, Huiqiang; Yu, Chenhui; Chen, Changqing

2009-08-01

404

27Al-NQR/NMR Study of Kondo Semiconductor CeFe2Al10  

NASA Astrophysics Data System (ADS)

27Al-NQR/NMR measurements have been performed on CeFe2Al10 in relevance to the novel phase below T0=27 K of isostructural CeRu2Al10. NQR peaks are assigned to five crystallographically inequivalent Al sites. No splitting of the NQR spectra down to 1.5 K confirms the lack of phase transition in this compound. The gaplike decrease in the spin-lattice relaxation rate 1/T1 above about 20 K, following the Korringa law (T1T = const.) below 20 K, indicates a pseudogap opening near the Fermi level. The gap magnitude of 70 K with a mid-gap state of 42% is estimated based on a rectangular density of states. The gap magnitude is much larger than the gap of 15 K evaluated previously from the electrical resistivity, which suggests CeFe2Al10 to be a Kondo semiconductor with a Kondo temperature much higher than 300 K.

Kawamura, Yukihiro; Edamoto, Shingo; Takesaka, Tomoaki; Nishioka, Takashi; Kato, Harukazu; Matsumura, Masahiro; Tokunaga, Yo; Kambe, Shinsaku; Yasuoka, Hiroshi

2010-10-01

405

Photoionization electronic spectroscopy of AlAg  

SciTech Connect

AlAg is produced in a supersonic molecular beam by laser vaporization of alloy samples in a pulsed nozzle cluster source. Electronic spectroscopy is studied with resonant two-photon photoionization. In addition to the two electronic excited states previously reported by Clements and Barrow, we have observed ten new states. Vibrational analyses are presented for each of these states, and rotational analyses are given for selected states. The number and characteristics of these excited states are compared to the predictions of recent [ital ab] [ital initio] calculations.

Robbins, D.L.; Yeh, C.S.; Pilgrim, J.S.; Lang, G.L.; Duncan, M.A. (Department of Chemistry, University of Georgia, Athens, Georgia 30602 (United States))

1994-04-01

406

Development of SiAlON materials  

NASA Technical Reports Server (NTRS)

Cold pressing and sintering techniques were used to produce ceramic bodies in which the major phase was beta prime Si3-Al-O-N4 solid solution. A variety of foreign oxides were used to promote liquid phase sintering, and this resulted in the incorporation of additional solid phases in the ceramic bodies which controlled elevated temperature properties. None of the bodies studied to date exhibited both adequate high temperature mechanical properties and oxidation resistance. Criteria are suggested to guide the formulation of bodies with improved high temperature properties.

Layden, G. K.

1977-01-01

407

Radikale onkologische Chirurgie als Therapieprinzip beim Pankreaskarzinom  

Microsoft Academic Search

Zusammenfassung  \\u000a Grundlagen: Mit den heutigen tiefen Morbiditäts-und Mortalitätsraten für Pankreasresektionen ist die Indikationsstellung für eine Standard-\\u000a oder pyloruserhaltende Whipple-Operation weniger restriktiv zu stellen.\\u000a \\u000a \\u000a Methodik: Pankreasresektionen für Karzinome sollten deshalb in kurativer oder palliativer Absicht, wenn immer möglich, durchgeführt\\u000a werden. Verlangt werden dafür erfahrene Chirurgen mit über 10 Pankreaseingriffen pro Jahr und einer Mortalität von unter 10%.\\u000a Als Standard gilt eine

H. U. Baer; J. M. Läuffer; Ch Sadowski; M. W. Büchler

1997-01-01

408

Orbit stability of the ALS storage ring  

SciTech Connect

The Advanced Light Source (ALS) storage ring, a synchrotron light source of the third generation, is specified to maintain its electron orbit stable within one tenth of the rms beam size. In the absence of a dedicated orbit feed-back system, several orbit-distorting effects were investigated, aided by a new interactive simulation tool, the code TRACY V. The effort has led to a better understanding of the behavior of a variety of accelerator subsystems and in consequence produced a substantial improvement in day-to-day orbit stability.

Keller, R.; Nishimura, H.; Biocca, A. [and others

1997-05-01

409

Influence of Reaction with XeF2 on Surface Adhesion of Al and Al2O3 Surfaces  

SciTech Connect

The change of surface adhesion after fluorination of Al and Al{sub 2}O{sub 3} surfaces using XeF{sub 2} was investigated with atomic force microscopy. The chemical interaction between XeF{sub 2} and Al and Al{sub 2}O{sub 3} surfaces was studied by in situ x-ray photoelectron spectroscopy. Fresh Al and Al{sub 2}O{sub 3} surfaces were obtained by etching top silicon layers of Si/Al and Si/Al{sub 2}O{sub 3} with XeF{sub 2}. The surface adhesion and chemical composition were measured as a function of time after the exposure to air or annealing (at 200 C under vauum). The correlation between the adhesion force increase and presence of AlF{sub 3} on the surface was revealed.

Zhang, Tianfu; Park, Jeong Y.; Huang, Wenyu; Somorjai, Gabor A.

2008-07-28

410

Interfacial microstructure and growth mechanism of Al4C3 in Grf/Al composites fabricated by liquid pressure method.  

PubMed

In this study, Grf/Al composite was fabricated by liquid pressure method. The diffusion layer and the nucleation and growth of Al4C3 were observed at the interface of Grf/Al composites by TEM and HRTEM. The growth mechanism of Al4C3 was analyzed in detail by crystallography theory. It was found that Al4C3 had no phase relations with the carbon fiber. (0001) layer of Al4C3 was parallel with main growth direction. Both the diffusion layer at the interface and crystal structure of Al4C3 affected the shape of Al4C3. At a certain position, Al4C3 could connect two fibers when the fibers were close to each other. PMID:25041826

Xu, Wang; Chenchong, Wang; Zhichao, Zhang; Ping, Liang; Yanhua, Shi; Guofu, Zhang

2014-10-01

411

Influence of the Al source and synthesis of ordered Al-SBA-15 hexagonal particles with nanostairs and terraces.  

PubMed

We investigated the effect of various aluminum sources on the morphology and microstructure of nanoporous Al-SBA-15. With aluminum tri-sec-butoxide (Al-TSB), very large, ordered hexagonal rods of Al-SBA-15 covered by nanostairs and terraces were synthesized. Such a morphology was not obtained with an inorganic Al source (sodium aluminate) or with organic sources seemingly similar to Al-TSB, such as aluminum tri-tert-butoxide, aluminum tri-n-butoxide, or aluminum isopropoxide. The results obtained from X-ray diffraction, scanning electron microscopy/transmission electron microscopy, N(2) adsorption/desorption, and high-performance (129)Xe NMR suggest that preparing an organic Al-Si precursor by premixing liquid organic Al and Si sources (Al-TSB and tetraethyl orthosilicate) is crucial in obtaining highly ordered mesoporous Al-SBA-15 materials with a well-defined morphology. PMID:15723513

Li, Wenjiang; Huang, Shing-Jong; Liu, Shang-Bin; Coppens, Marc-Olivier

2005-03-01

412

Performance of LiAl/LiI(Al2O3)/FeS2 thermal batteries  

NASA Astrophysics Data System (ADS)

Performances of the LiAl/LiI(Al2O3)/FeS2 systems with different percentages of Al2O3 in the electrolyte were tested from 460 C to 580 C at various current densities and were compared with the performance of the LiAl/LiCl-KCl/FeS2 system. The results of single-cell and battery tests indicate that the LiAl/LiI(Al2O3)/FeS2 system has a feasibility for thermal potential applications. Compared to the LiAl/LiCl-KCl/FeS2 system, the LiI(Al2O3)-based system has poorer specific conductance and lower cell potential, but longer discharge life and greater capacity. A salient feature of the LiI(Al2O3)-based system, important for reliability considerations, is its apparent greater flexibility in battery internal heat control.

Lin, Yung-Hsin; Yu, Kuo-Tung; Yao, Pei-Chin; Hsu, Shu-En

413

Transplacental passage of 26Al from pregnant rats to fetuses and 26Al transfer through maternal milk to suckling rats  

NASA Astrophysics Data System (ADS)

Aluminium (Al) is toxic to the growth of fetuses and sucklings. However, the incorporation of Al into fetuses and sucklings in the periods of gestation and lactation has not been well clarified because Al lacks a suitable isotope for a tracer experiment. In this study, we used 26Al (a radioisotope of Al with half-life of 716,000 yr) as a tracer, and measured 26Al incorporation into fetuses and sucklings by accelerator mass spectrometry (AMS). To investigate Al incorporation into fetuses through transplacental passage, 26Al ( 26AlCl 3) was subcutaneously injected into pregnant rats on day 15 of gestation. 26Al was also subcutaneoulsy injected into lactating rats from day 1 to day 20 postpartum. By day 20 of gestation, 0.2% of the 26Al injected into a pregnant rat had been transferred to the fetuses, and 26Al was detected in the brain and liver of the fetuses. On day 9 postpartum, high levels of 26Al were demonstrated in the brain, liver, kidneys and blood of suckling rats. It is concluded that 26Al subcutaneously injected into pregnant rats and/or lactating rats is incorporated into their offspring through transplacental passage and/or maternal milk.

Yumoto, S.; Nagai, H.; Matsuzaki, H.; Kobayashi, T.; Tada, W.; Ohki, Y.; Kakimi, S.; Kobayashi, K.

2000-10-01

414

TEM characterization of Al/Al{sub 2}O{sub 3} composite fabricated by reactive metal infiltration  

SciTech Connect

The microstructure of Al/{alpha}-Al{sub 2}0{sub 3} composites made by infiltrating Al into dense mullite preforms has been characterized using transmission electron microscopy. Observations revealed that the formation of the Al/Al{sub 2}0{sub 3} composites involves three stages. Initially, Al infiltrates into a dense mullite preform through grain boundary diffusion, and reacts with mullite at grain boundaries to form a partial reaction zone. Then, a complete reaction takes place in the reaction region between the partial reaction zone and the full reaction zone to convert the dense mullite preform to a composite of {alpha}-Al{sub 2}0{sub 3} (matrix) and an Al-Si phase (thin channels). Finally, the reduced Si from the reaction diffuses out of the Al/Al{sub 2}0{sub 3} composite through the metal channels, whereas Al from the molten Al pool is continuously drawn to the reaction region until the mullite preform is consumed or the sample is removed from the molten Al pool. Based on the observed microstructure, infiltration mechanisms have been discussed, and a growth model of the composites is proposed in which the process involves repeated nucleation of Al{sub 2}0{sub 3} grains and grain growth.

Gao, Y.; Jia, J. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Materials Engineering; Loehman, R.E.; Ewsuk, K.G. [Sandia National Labs., Albuquerque, NM (United States)

1994-12-31

415

Minutes No. 105 Meeting: 2012 New SUB Committee  

E-print Network

Coordinator), Emme Ann Lee (SEEDS, Vermicompost Coordinator and Researcher) Attendees (Regrets) Name.2 Approval of Meeting Minutes 105.3 SEEDS and Vermicomposting Presentation (Liska and Emme) "Whereas Vermicomposting unit Discussion of the SEEDS Vermicomposting Project: Pilot program running currently

Pulfrey, David L.

416

High-temperature deformation of uniaxially aligned lamellar TiAl/Ti{sub 3}Al  

SciTech Connect

Uniaxially aligned polysynthetically twinned two-phase TiAl/Ti{sub 3}Al material is produced by induction zone melting and deformed in uniaxial compression. Above 1,000 K the strain rate sensitivity is independent of the lamellar orientation and increases strongly with increasing deformation temperature. Results for the strain rate sensitivity parameters are somewhat lower than those obtained for {gamma}-TiAl single- and polycrystals. If the lamellae are oriented parallel or perpendicular to the deformation axis, the flow stress decreases with increasing strain. After plastic deformation the dislocation density in the lamellae is remarkably low indicating recovery processes. At the lamellar interfaces misfit dislocations and periodic arrangements of dislocations with Burgers vectors inclined to the lamellar boundaries are found. In contrast to deformation at lower temperatures, deformation twinning is rare.

Heinrich, H.; Abaecherli, V.; Wilkins, D.J.; Kostorz, G.

1999-07-01

417

Local stress-induced effects on AlGaAs/AlOx oxidation front shape  

NASA Astrophysics Data System (ADS)

The lateral oxidation of thick AlGaAs layers (>500 nm) is studied. An uncommon shape of the oxide tip is evidenced and attributed to the embedded stress distribution, inherent to the oxidation reaction. Experimental and numerical studies of the internal strain in oxidized AlxGa1-xAs/GaAs structures were carried out by dark-field electron holography and finite element methods. A mapping of the strain distribution around the AlGaAs/oxide interface demonstrates the main role of internal stress on the shaping of the oxide front. These results demonstrate the high relevance of strain in oxide-confined III-V devices, in particular, with over-500-nm thick AlOx confinement layers.

Chouchane, F.; Almuneau, G.; Cherkashin, N.; Arnoult, A.; Lacoste, G.; Fontaine, C.

2014-07-01

418

A Correlation Between Failure Angle and Constituent for Al-AlN Composites Under Uniaxial Tensile Conditions  

NASA Astrophysics Data System (ADS)

Al-AlN composites with different AlN reinforcement fractions and porosity were fabricated through nitridation of laser-sintered AA 6061 powder followed by infiltration with AA 6061. Their failure behaviors were investigated under uniaxial tensile loading conditions. Tensile testing and fractography indicate that the fracture mode changes gradually from ductile to brittle fracture with increasing AlN reinforcement or porosity. An analysis of the fractured Al-AlN tensile samples reveals that the failure surface angle, ?, is dictated by the volume fraction of the matrix, f m , in a form of tan ? = f {/m 5.5}.

Yu, Peng; Schaffer, G. B.; Qian, Ma

2012-09-01

419

Growth and characterization of TiAlN/CrAlN superlattices prepared by reactive direct current magnetron sputtering  

SciTech Connect

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. Subsequently, nanolayered multilayer coatings of TiAlN/CrAlN were deposited on silicon and mild steel (MS) substrates at different modulation wavelengths ({lambda}) with a total thickness of approximately 1.0 {mu}m. The modulation wavelengths were calculated from the x-ray reflectivity data using modified Bragg's law. TiAlN/CrAlN multilayer coatings were textured along (111) for {lambda}<200 A and the XRD patterns showed the formation of superlattice structure for coatings deposited at {lambda}=102 A. The x-ray reflectivity data showed reflections of fifth and seventh orders for multilayer coatings deposited at {lambda}=102 and 138 A, respectively, indicating the formation of sharp interfaces between TiAlN and CrAlN layers. The cross-sectional scanning electron microscopy image of TiAlN/CrAlN multilayer coatings indicated a noncolumnar and dense microstructure. A maximum hardness of 39 GPa was observed for TiAlN/CrAlN multilayer coatings deposited at {lambda}=93 A, which was higher than the rule-of-mixture value (30 GPa) for TiAlN and CrAlN. Study of thermal stability of the coatings in air using micro-Raman spectroscopy indicated that the TiAlN/CrAlN multilayer coatings were stable up to 900 deg. C in air. TiAlN/CrAlN multilayer coatings also exhibited improved corrosion resistance when compared to the MS substrate.

Barshilia, Harish C.; Deepthi, B.; Rajam, K. S.; Bhatti, Kanwal Preet; Chaudhary, Sujeet [Surface Engineering Division, National Aerospace Laboratories, Post Bag No. 1779, Bangalore 560 017 (India); Department of Physics, Indian Institute of Technology, Delhi, New Delhi 110 016 (India)

2009-01-15

420

The embrittlement of Al-Zn-Mg and Al-Mg alloys by water vapor  

NASA Astrophysics Data System (ADS)

Al4.5Zn1.5Mg and Al5Mg were reacted in water-vapor saturated air (WVSA) at 120°C and tensile tested. After an initial loss of ductility with exposure time, probably caused by hydrogen embrittlement of the grain boundaries, between 15 hours and 25 hours exposure the mechanical properties of Al4.5Zn1.5Mg improved, this effect being due both to a reduced corrosion activity of the grain boundaries in producing embrittling hydrogen at the external surface and to grain boundary MgZn2 precipitates acting as hydrogen traps. After 25 hours exposure water was shown to penetrate the grain boundaries, and a layered corrosion product identified as the aluminum hydroxides boehmite and diaspore was formed. This resulted in a marked fall of ductility. Re-solution heat treatment and reaging partially recovered the mechanical properties of Al4.5Zn1.5Mg if the exposure time was less than 50 hours, and would not recover properties for longer exposure times. Small additions (0.1 pct) of iron and nickel to Al4.5Zn1.5Mg lessened the grain boundaries’ sensitivity to corrosive attack whereas the addition of 0.1 pct copper did not. Also, the former two additions did not cause the relative ductility increase during 15 to 25 hours exposure in WVSA at 120°C shown by Al4.5Zn1.5Mg. It is proposed that these elements alter the magnesium segregation levels at the grain boundaries which in turn affects their electrochemical attack.

Tuck, C. D. S.

1985-08-01

421

InAs/AlSb short wavelength quantum cascade lasers.  

E-print Network

??Application of InAs/AlSb materials system for development of short-wavelength quantum cascade lasers is explored. Molecular beam epitaxy (MBE) technology allowing to grow multiperiodical unstrained InAs/AlSb… (more)

Devenson, Jan

2010-01-01

422

75 FR 20773 - Establishment of Class E Airspace; Jackson, AL  

Federal Register 2010, 2011, 2012, 2013

...09-ASO-27] Establishment of Class E Airspace; Jackson, AL AGENCY: Federal Aviation Administration (FAA...December 7, 2009 that establishes Class E airspace at Jackson Muni, Jackson, AL. DATES: Effective Date: 0901 UTC, April...

2010-04-21

423

PIT INITIATION IN AlO{sub X}/Al THIN FILMS  

SciTech Connect

The electrochemical responses of AlO{sub x}/Al thin films have been investigated as a function of film growth conditions which produce films with different grain orientation, size and morphology. Films with smooth, 150 nm diameter, randomly oriented grains show a higher pitting potential and lower passive current than those films with large grain-boundary grooving from a mixture of smooth micron-sized, (200)-oriented grains and 300--500 nm diameter, (220)-oriented grains. These results suggest that surface roughness from grain-boundary grooving affects the pitting resistance more strongly than does the grain boundary density.

SON,K.A.; BARBOUR,J.C.; MISSERT,N.; WALL,F.D.; COPELAND,R.G.; MARTINEZ,M.A.; MINOR,K.G.; BUCHHEIT,R.G.; ISAACS,H.S.

1998-11-01

424

Microstructure and Creep Properties of TiAl-Ti3Al In-Situ Composites  

SciTech Connect

Objectives: {lg_bullet} Exploit thermomechanical-processing techniques to fabricate TiAl/Ti3Al in-situ laminate composites with the size of lamella width down to submicron or nanometer length-scales. {lg_bullet} Characterize microstructure and elevated-temperature creep resistance of the in-situ composites. {lg_bullet} Investigate the fundamental interrelationships among microstructures, alloying additions, and mechanical properties of the in-situ composites so as to achieve the desired properties of the in-situ composites for high-temperature structural applications.

Hodge, A M; Hsiung, L L

2004-02-18

425

InAlGaAs/AlGaAs Superlattices for Polarized Electron Photocathodes  

SciTech Connect

Highly efficient emitters of polarized electrons based on the InAlGaAs/AlGaAs superlattice give an optimistic prognosis to explorations of such structures as the sources for accelerators. A new set of these SL structures with minimized conduction band offset was designed and recently tested. A new technology of surface protection in MBE growth leads to a significantly reduced heat-cleaning temperature. At these lowered cleaning temperatures, the thermal degradation of the working structure parameters is avoided. As a result a polarization P of up to 91% at corresponding quantum efficiency (QE) of 0.3% was achieved at room temperature.

Mamaev, Yu.A.; Subashiev, A.V.; Yashin, Yu.P.; Gerchikov, L.G.; /St. Petersburg Polytechnic Inst.; Maruyama, T.; Luh, D.-A.; Clendenin, J.E.; /SLAC; Ustinov, V.M.; Zhukov,; /Ioffe Phys. Tech. Inst.

2005-08-15

426

Lasing characteristics of visible AlGaInP/AlGaAs vertical-cavity lasers  

SciTech Connect

We report the lasing characteristics of gain-guided AlGaInP/AlGaAs visible vertical-cavity surface-emitting laser diodes. At room temperature, continuous-wave operation is achieved over the wavelength range of 657--685 nm with the minimum threshold current at 670 nm. Devices with a 10-[mu]m diameter have threshold currents as low as 1.25 mA at room temperature (297 K) and 0.8 mA at 250 K. In addition, a single predetermined linear polarization state is found, independent of the lasing mode order and operating temperature.

Choquette, K.D.; Schneider, R.P. Jr.; Lott, J.A. (Sandia National Laboratories, Albuquerque, New Mexico 87185-5800 (United States))

1994-07-01

427

Lasing characteristics of visible AlGaInP/AlGaAs vertical-cavity lasers.  

PubMed

We report the lasing characteristics of gain-guided AlGaInP/AlGaAs visible vertical-cavity surface-emitting laser diodes. At room temperature, continuous-wave operation is achieved over the wavelength range of 657-685 nm with the minimum threshold current at 670 nm. Devices with a 10-microm diameter have threshold currents as low as 1.25 mA at room temperature (297 K) and 0.8 mA at 250 K. In addition, a single predetermined linear polarization state is found, independent of the lasing mode order and operating temperature. PMID:19844504

Choquette, K D; Schneider, R P; Lott, J A

1994-07-01

428

Fabrication and Characterization of Thin-Barrier AlGaN\\/AlN\\/GaN HEMTs  

Microsoft Academic Search

The growth, fabrication, and performance of Al0.5Ga0.5N\\/AlN\\/GaN high-electron-mobility transistors (HEMTs) with a total barrier thickness of 7 nm are reported. An optimized surface passivation and an ohmic recess etch yield HEMTs exhibiting 0.72 S\\/mm peak extrinsic dc transconductance at a current density of 0.47 A\\/mm. Devices with a gate length of 90 nm achieve 78 GHz unity-current-gain frequency and up

Jonathan G. Felbinger; Martin Fagerlind; Olle Axelsson; Niklas Rorsman; Xiang Gao; Shiping Guo; William J. Schaff; Lester F. Eastman

2011-01-01

429

Vanishing quasiparticle density in a hybrid Al/Cu/Al single-electron transistor  

NASA Astrophysics Data System (ADS)

The achievable fidelity of many nanoelectronic devices based on superconducting aluminum is limited by either the density of residual nonequilibrium quasiparticles nqp or the density of quasiparticle states in the gap, characterized by Dynes parameter ?. We infer upper bounds nqp<0.033?m-3 and ?<1.6×10-7 from transport measurements performed on Al/Cu/Al single-electron transistors, improving previous results by an order of magnitude. Owing to efficient microwave shielding and quasiparticle relaxation, a typical number of quasiparticles in the superconducting leads is zero.

Saira, O.-P.; Kemppinen, A.; Maisi, V. F.; Pekola, J. P.

2012-01-01

430

InAs\\/AlGaAs QDs for intersubband devices  

Microsoft Academic Search

InAs quantum dots were grown on AlxGa1?xAs surfaces with varying Al concentrations. Atomic force microscopy measurements conducted on surface quantum dots showed that surfaces with higher Al concentrations produce smaller dots compared to GaAs surfaces. Photoluminescence measurements performed on buried quantum dots showed a blue shift and spectral broadening of the luminescence signal for increasing Al concentrations. For Al concentrations

M. Schramboeck; A. M. Andrews; P. Klang; W. Schrenk; G. Hesser; F. Schäffler; G. Strasser

2008-01-01

431

Growth and Oxidation of Thin Film Al(2)Cu  

SciTech Connect

Al{sub 2}Cu thin films ({approx} 382 nm) are fabricated by melting and resolidifying Al/Cu bilayers in the presence of a {micro} 3 nm Al{sub 2}O{sub 3} passivating layer. X-ray Photoelectron Spectroscopy (XPS) measures a 1.0 eV shift of the Cu2p{sub 3/2} peak and a 1.6 eV shift of the valence band relative to metallic Cu upon Al{sub 2}Cu formation. Scanning Electron microscopy (SEM) and Electron Back-Scattered Diffraction (EBSD) show that the Al{sub 2}Cu film is composed of 30-70 {micro}m wide and 10-25 mm long cellular grains with (110) orientation. The atomic composition of the film as estimated by Energy Dispersive Spectroscopy (EDS) is 67 {+-} 2% Al and 33 {+-} 2% Cu. XPS scans of Al{sub 2}O{sub 3}/Al{sub 2}Cu taken before and after air exposure indicate that the upper Al{sub 2}Cu layers undergo further oxidation to Al{sub 2}O{sub 3} even in the presence of {approx} 5 nm Al{sub 2}O{sub 3}. The majority of Cu produced from oxidation is believed to migrate below the Al{sub 2}O{sub 3} layers, based upon the lack of evidence for metallic Cu in the XPS scans. In contrast to Al/Cu passivated with Al{sub 2}O{sub 3}, melting/resolidifying the Al/Cu bilayer without Al{sub 2}O{sub 3} results in phase-segregated dendritic film growth.

SON,KYUNG-AH; MISSERT,NANCY A.; BARBOUR,J. CHARLES; HREN,J.J.; COPELAND,ROBERT GUILD; MINOR,KENNETH G.

2000-01-18

432

Quantitative Aspects of 27Al MAS NMR of Calcium Aluminoferrites  

Microsoft Academic Search

27Al MAS NMR spectra of synthetic calcium aluminoferrites, Ca2AlxFe2?xO5 with x = 0.93, 1, 1.33, reveal only a few percent of the expected intensity for the 27Al central transition, indicating that the calcium aluminoferrite phase in Portland cements can barely be observed by 27Al MAS NMR. This result supports the use of 27Al MAS NMR for quantitative analysis of the

Jørgen Skibsted; Hans J. Jakobsen; Christopher Hall

1998-01-01

433

Application of cast gamma TiAl for automobiles  

Microsoft Academic Search

Studies of cast gamma TiAl applied for engine valves and turbocharger confirmed excellent performances. The durability of TiAl valves was also proven. Two cast gamma TiAl alloys were developed for the engine valves and the turbine wheels of turbochargers. New precision casting process of LEVICAST and induction brazing process of the gamma TiAl and alloy steels were proposed as advanced

T. Noda

1998-01-01

434

Development of Enhancement Mode AlN/GaN HEMTs  

SciTech Connect

Demonstration of enhancement mode AlN/GaN high electron mobility transistor (HEMT) using oxygen plasma treatment on the gate area prior to the gate metalliation deposition was achieved. Starting with a depletion mode AlN/GaN HEMT, the threshold voltage of the HEMT could be shifted from 3.2 to 1V depending on the oxygen plasma treatment time to convert the AlN into Al oxide. The gate current was also reduced when the threshold voltage

Chang, C. Y. [University of Florida; Pearton, S. J. [University of Florida; Lo, C. F. [University of Florida; Kravchenko, Ivan I [ORNL; Dabiran, A. M. [SVT Associates, Inc.; Wowchak, A. M. [SVT Associates, Inc.; Cui, B. [SVT Associates, Inc.; Chow, P. P. [SVT Associates, Inc.; Ren, F. [University of Florida

2009-01-01

435

Al-Fe-Ni (Aluminum-Iron-Nickel)  

SciTech Connect

[88Ray] reviewed the experimental results on the phase equilibria of this system. The reviewed results were presented as: (1) liquidus and solidus projections for Al-poor Fe-Ni alloys and for compositions near the Al-corner; (2) a reaction sequence for the solidification reactions; (3) isothermal sections at 1250, 950, 850, and 750{degrees}C for Al-poor Fe-Ni compositions; and (4) an isothermal section at 600{degrees}C near the Al-corner.

Raghavan, V.

1994-08-01

436

Mechanisms of elevated-temperature deformation in the B2 aluminides NiAl and CoAl  

NASA Technical Reports Server (NTRS)

A strain rate change technique, developed previously for distinguishing between pure-metal and alloy-type creep behavior, was used to study the elevated-temperature deformation behavior of the intermetallic compounds NiAl and CoAl. Tests on NiAl were conducted at temperatures between 1100 and 1300 K while tests on CoAl were performed at temperatures ranging from 1200 to 1400 K. NiAl exhibits pure-metal type behavior over the entire temperature range studied. CoAl, however, undergoes a transition from pure-metal to alloy-type deformation behavior as the temperature is decreased from 1400 to 1200 K. Slip appears to be inherently more difficult in CoAl than in NiAl, with lattice friction effects limiting the mobility of dislocations at a much higher tmeperature in CoAl than in NiAl. The superior strength of CoAl at elevated temperatures may, therefore, be related to a greater lattice friction strengthening effect in CoAl than in NiAl.

Yaney, D. L.; Nix, W. D.

1988-01-01

437

Mechanochemical Behavior of NiO-Al-Fe Powder Mixtures to Produce (Ni, Fe)3Al-Al2O3 Nanocomposite Powder  

NASA Astrophysics Data System (ADS)

(Ni, Fe)3Al-30 vol pct Al2O3 nanocomposite powder was synthesized by mechanochemical reaction of Fe-NiO-Al powder mixtures. Structural evolution during mechanical alloying was studied by employing X-ray diffractometry (XRD), differential thermal analysis (DTA), and transmission electron microscopy (TEM). After 78 minutes of milling, the (Ni, Fe)3Al-30 vol pct Al2O3 nanocomposite can be synthesized by reaction 3Fe + 7Al + 6NiO with a combustion mode. DTA results revealed that milling for 60 minutes decreases the temperature of reaction from 1040 K to 898 K (767 °C to 625 °C). TEM images corroborate a homogenous dispersion of reinforcements in the matrix of the nanocomposite proving that the reduction in the crystallite size of both reinforcements and matrix is within the nanometer range.

Adabavazeh, Z.; Karimzadeh, F.; Enayati, M. H.

2012-09-01

438

Effect of growth temperature of initial AlN buffer on the structural and optical properties of Al-rich AlGaN  

NASA Astrophysics Data System (ADS)

High Al-content Al xGa 1-xN epilayers with x=0.62-0.64 were grown on AlN buffer by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). As growth temperature of initial AlN buffer increased, the full-width at half-maximum (FWHM) of the AlGaN (0 0 2) rocking curves decreased from 942 to 637 arcsec. Meanwhile, vacuum ultraviolet (VUV) photoluminescence (PL) spectroscopy showed that band edge exciton transition was greatly intensified, while deep level radiative recombination especially peaked at 304 nm was effectively suppressed. They were ascribed to the reducing of threading dislocations (TDs) in the AlGaN epilayers.

Peng, M. Z.; Guo, L. W.; Zhang, J.; Yu, N. S.; Zhu, X. L.; Yan, J. F.; Wang, Y.; Jia, H. Q.; Chen, H.; Zhou, J. M.

2007-09-01

439

Mixing of Al into uranium silicides reactor fuels  

SciTech Connect

SEM observations have shown that irradiation induced interaction of the aluminum cladding with uranium silicide reactor fuels strongly affects both fission gas and fuel swelling behaviors during fuel burn-up. The authors have used ion beam mixing, by 1.5 MeV Kr, to study this phenomena. RBS and the {sup 27}Al(p, {gamma}) {sup 28}Si resonance nuclear reaction were used to measure radiation induced mixing of Al into U{sub 3}Si and U{sub 3}Si{sub 2} after irradiation at 300 C. Initially U mixes into the Al layer and Al mixes into the U{sub 3}Si. At a low dose, the Al layer is converted into UAl{sub 4} type compound while near the interface the phase U(Al{sub .93}Si{sub .07}){sub 3} grows. Under irradiation, Al diffuses out of the UAl{sub 4} surface layer, and the lower density ternary, which is stable under irradiation, is the final product. Al mixing into U{sub 3}Si{sub 2} is slower than in U{sub 3}Si, but after high dose irradiation the Al concentration extends much farther into the bulk. In both systems Al mixing and diffusion is controlled by phase formation and growth. The Al mixing rates into the two alloys are similar to that of Al into pure uranium where similar aluminide phases are formed.

Ding, F.R.; Birtcher, R.C.; Kestel, B.J.; Baldo, P.M. [Argonne National Lab., IL (United States). Materials Science Div.

1996-11-01

440

OVERVIEW NO. 136 DIFFUSION IN THE TiAl SYSTEM  

E-print Network

OVERVIEW NO. 136 DIFFUSION IN THE Ti±Al SYSTEM Y. MISHIN1 { and Chr. HERZIG2 1 DepartmentÐMany properties of industrial Ti±Al alloys, such as high-temperature stability of the lamellar structure and creep and design of industrial Ti±Al alloys. This paper gives an overview of recent progress in experimental

Mishin, Yuri

441

The Practical Enactment of Adventure Learning: Where Will You AL@?  

ERIC Educational Resources Information Center

The Adventure Learning (AL) approach to designing and implementing learning experiences has great potential for practitioners. This manuscript delineates the practical enactment of AL to support the K-12 community, teacher educators, and residential environmental science program providers in the conceptualization and delivery of their own AL…

Miller, Brant G.; Hougham, R. Justin; Eitel, Karla Bradley

2013-01-01

442

Supporting Information Koenderink et al. 10.1073/pnas.0903974106  

E-print Network

filaments or FLNa dimers per actin filament. Koenderink et al. www.pnas.org/cgi/content/short/0903974106 4 and passive actin­scruin network. Koenderink et al. www.pnas.org/cgi/content/short/0903974106 5 of 5 #12;Supporting Information Koenderink et al. 10.1073/pnas.0903974106 FLNa/actin filament myosin

Fraden, Seth

443

Igor Kuznecov MOVPE von AlGaN-Schichten mit  

E-print Network

moglich, die Emissionswellenlange einer LED von der Wellenlange des GaN (365nm) bis zur Wellenlange des Al Diplomarbeit ist das Wachstum von LED-Schichten mittels MOVPE. Dabei muss die Komposition des AlGaN und dieIgor Kuznecov MOVPE von AlGaN-Schichten mit hohem Aluminiumgehalt Es gibt zahlreiche

Nabben, Reinhard

444

Effect of Ar gas pressure on growth, structure, and mechanical properties of sputtered Ti, Al, TiAl, and Ti 3Al films  

Microsoft Academic Search

Single layers of Ti, Al, TiAl and Ti3Al were sputter deposited on to 2? oxidized Si ?111? wafers and 7059 Corning Glass to study the effect of film thickness, temperature, and sputtering gas pressure on the mechanical and physical properties. In the present investigation, sputtering gas pressure was varied from 2 mT to 10 mT. The film thickness was varied

M. Chinmulgund; R. B. Inturi; J. A. Barnard

1995-01-01

445

Spinelisation and properties of Al 2O 3–MgAl 2O 4–C refractory: Effect of MgO and Al 2O 3 reactants  

Microsoft Academic Search

The effect of particle size of MgO and Al2O3 on the spinel formation associated with permanent linear change on reheating (PLCR) and microstructure of Al2O3–MgAl2O4–C refractory is investigated as a function of heating cycle at 1600°C with 2h holding at each cycle. It was found that rate of spinel formation and associated volume expansion is very much dependent on the

H. S. Tripathi; A. Ghosh

2010-01-01

446

Al2C monolayer: the planar tetracoordinate carbon global minimum  

NASA Astrophysics Data System (ADS)

Inspired by our theoretical finding that C2Al62- has a planar D2h minimum with two planar tetracoordinate carbons (ptCs), we computationally designed a new two-dimensional (2D) inorganic material, an Al2C monolayer. All carbons in this monolayer are ptC's, stabilized inductively by binding to four electropositive Al atoms in the same plane. The Al2C monolayer is semiconducting with an indirect minimum band gap and a slightly larger direct band gap. Good persistence of the Al2C monolayer is indicated by its moderate cohesive energy, the absence of imaginary modes in its phonon spectrum, and the high melting point predicted by molecular dynamics (MD) simulations. Moreover, a particle-swarm optimization (PSO) global minimum search found the Al2C monolayer to be the lowest-energy 2D structure compared to other Al2C alternatives. Dividing the Al2C monolayer results in one-dimensional (1D) Al2C nanoribbons, which are computed to have quite rich characteristics such as direct or indirect band gaps with various values, depending on the direction of the division and the resulting edge configuration.Inspired by our theoretical finding that C2Al62- has a planar D2h minimum with two planar tetracoordinate carbons (ptCs), we computationally designed a new two-dimensional (2D) inorganic material, an Al2C monolayer. All carbons in this monolayer are ptC's, stabilized inductively by binding to four electropositive Al atoms in the same plane. The Al2C monolayer is semiconducting with an indirect minimum band gap and a slightly larger direct band gap. Good persistence of the Al2C monolayer is indicated by its moderate cohesive energy, the absence of imaginary modes in its phonon spectrum, and the high melting point predicted by molecular dynamics (MD) simulations. Moreover, a particle-swarm optimization (PSO) global minimum search found the Al2C monolayer to be the lowest-energy 2D structure compared to other Al2C alternatives. Dividing the Al2C monolayer results in one-dimensional (1D) Al2C nanoribbons, which are computed to have quite rich characteristics such as direct or indirect band gaps with various values, depending on the direction of the division and the resulting edge configuration. Electronic supplementary information (ESI) available: Complete citation of ref. 50, the band structure of an Al2C monolayer computed using the HSE06 functional, snapshots of MD simulations, and bulk structures of Al2C-II and Al2C-III. See DOI: 10.1039/c4nr01972e

Li, Yafei; Liao, Yunlong; Schleyer, Paul Von Ragué; Chen, Zhongfang

2014-08-01

447

Ab initio molecular dynamics of Al irradiation-induced processes during Al{sub 2}O{sub 3} growth  

SciTech Connect

Al bombardment induced structural changes in {alpha}-Al{sub 2}O{sub 3} (R-3c) and {gamma}-Al{sub 2}O{sub 3} (Fd-3m) were studied using ab initio molecular dynamics. Diffusion and irradiation damage occur for both polymorphs in the kinetic energy range from 3.5 to 40 eV. However, for {gamma}-Al{sub 2}O{sub 3}(001) subplantation of impinging Al causes significantly larger irradiation damage and hence larger mobility as compared to {alpha}-Al{sub 2}O{sub 3}. Consequently, fast diffusion along {gamma}-Al{sub 2}O{sub 3}(001) gives rise to preferential {alpha}-Al{sub 2}O{sub 3}(0001) growth, which is consistent with published structure evolution experiments.

Music, Denis; Nahif, Farwah; Friederichsen, Niklas; Schneider, Jochen M. [Materials Chemistry, RWTH Aachen University, D-52056 Aachen (Germany); Sarakinos, Kostas [Plasma and Coatings Physics Division, Linkoeping University, SE-58183 Linkoeping (Sweden)

2011-03-14

448

First-principles investigation of mechanical behavior of B2 type aluminides: FeAl and NiAl  

SciTech Connect

First-principles calculations of the elastic constants, shear fault energies, and cleavage strength of NiAl and FeAl are presented. For NiAl, we find that the dissociation of {l angle}111{r angle} superdislocation into partial dislocations is unlikely, due to a high antiphase boundary energy and a weak repulsive elastic force between partial dislocations. FeAl has a high ideal cleavage strength as a result of the directional d-bond formation at the Fe sites. The strong ordering behavior of NiAl is explained in terms of the Al-to-Ni charge transfer and the repulsive interaction between Al atoms. The spontaneous glide decomposition of the {l angle}111{r angle} superdislocation in NiAl is also discussed. 8 refs., 2 figs., 2 tabs.

Fu, C.L.; Yoo, M.H.

1990-01-01

449

Investigation of the low-temperature AlGaN interlayer in AlGaN/GaN/AlGaN double heterostructure on Si substrate  

NASA Astrophysics Data System (ADS)

A low-temperature (LT) AlGaN interlayer is inserted in the Al0.1Ga0.9N back barrier layer of an Al0.2Ga0.8N/GaN/Al0.1Ga0.9N double heterostructure grown on a 150 mm Si substrate. It is found that the 21-nm-thick LT-AlGaN interlayer plays an important role in stress relaxation and dislocation reduction of the Al0.1Ga0.9N back barrier layer, especially for screw dislocation reduction. In addition, a buffer breakdown voltage higher than 600 V is achieved, which is much higher than those of conventional heterostructures. These results demonstrate the effectiveness of combining the LT-AlGaN interlayer and the Al0.2Ga0.8N/GaN/Al0.1Ga0.9N double heterostructure on a Si substrate to increase the breakdown voltage for high-power applications.

Hsiao, Yu-Lin; Wang, Yi-Jie; Chang, Chia-Ao; Weng, You-Chen; Chen, Yen-Yu; Chen, Kai-Wei; Maa, Jer-Shen; Chang, Edward Yi

2014-11-01

450

High temperature stability of multicomponent TiAlSiN and CrAlSiN coatings.  

PubMed

The high temperature oxidation behavior of TiAlSiN and CrAlSiN coatings was studied. These coatings were deposited on silicon substrates by using a cathodic-arc deposition system with lateral rotating arc cathodes. Titanium, chromium and Al88Si12 cathodes were used for the deposition of TiAlSiN and CrAlSiN coatings. All the deposited Ti(0.49)Al(0.44)Si(0.07)N, Ti(0.41)Al(0.51)Si(0.08)N and Cr(0.50)Al(0.440Si(0.06)N coatings showed B1-NaCl crystal structure and possessed nano-grain sizes of 6-8 nm. For the high temperature oxidation test, the coated samples were annealed at 900 degrees C in air for 2 hours. The Ti(0.41)Al(0.51)Si(0.08)N with higher Al and Si contents possessed lower oxidation rate than that of Ti(0.49)Al(0.44)Si(0.07)N. The oxide layer formed on the Ti(0.49)Al(0.44)Si(0.07)N coatings consisted of large TiO2 and TiAlSiN grains at the oxide-coating interface, followed by a layer of Al2O3 in the near-surface region. The oxidation rate of the Cr(0.50)Al(0.44)Si(0.06)N coated sample was much lower than that of the Ti(0.49)Al(0.44)Si(0.07)N and Ti(0.41)Al(0.51)Si(0.08)N. The dense Al2O3 with amorphous top layer at the oxide-coating interface retarded the diffusion of oxygen into the Cr(0.50)Al(0.44)Si(0.06)N. The deposited Cr(0.50)Al(0.44)Si(0.06)N showed a high temperature performance superior to those of the Ti(0.49)Al(0.44)Si(0.07)N and Ti(0.41)Al(0.51)Si(0.08)N. PMID:21128495

Chang, Yin-Yu; Chang, Chi-Pang

2010-07-01

451

Tunneling anisotropic magnetoresistance in Co/AlOx/Al tunnel junctions with fcc Co (111) electrodes  

NASA Astrophysics Data System (ADS)

Tunneling anisotropic magnetoresistance (TAMR) has been characterized in junctions comprised of face-centered cubic (fcc) Co (111) ferromagnetic electrodes grown epitaxially on sapphire substrates, amorphous AlOx tunnel barriers, and nonmagnetic Al counterelectrodes. Large TAMR ratios have been found, up to ˜7.5% and ˜11% (at 5 K), for the in-plane and out-of-plane magnetization geometry, respectively. Such large TAMR values were not expected a priori, given the weak anisotropy of the (bulk) Co bands due to spin-orbit interaction, and the absence of Co (111) surface states that cross the Fermi energy. Both the in-plane and out-of-plane TAMR effects exhibit a predominantly twofold symmetry, and a strong bias dependence. The in-plane TAMR shows a maximum along the (twofold) magnetic hard axis, suggesting a relation between magnetic anisotropy and TAMR. We propose that uniaxial strain in combination with Bychkov-Rashba spin-orbit interaction, producing an interfacial tunneling DOS that depends on the magnetization direction, is responsible for the TAMR effect. The importance of the interfacial Co/AlOx (electronic) structure for the TAMR effect is underlined by measurements on junctions with overoxidized AlOx barriers, which show markedly different bias and angle dependence.

Wang, K.; Tran, T. L. A.; Brinks, P.; Sanderink, J. G. M.; Bolhuis, T.; van der Wiel, W. G.; de Jong, M. P.

2013-08-01

452

A sulfur segregation study of PWA 1480, NiCrAl, and NiAl alloys  

NASA Technical Reports Server (NTRS)

Some nickel based superalloys show reduced oxidation resistance from the lack of an adherent oxide layer during high temperature cyclic oxidation. The segregation of sulfur to the oxide-metal interface is believed to effect oxide adhesion, since low sulfur alloys exhibit enhanced adhesion. X ray Photoelectron Spectroscopy (XPS) was combined with an in situ sample heater to measure sulfur segregation in NiCrAl, PWA 1480, and NiAl alloys. The polished samples with a 1.5 to 2.5 nm (native) oxide were heated from 650 to 1100 C with hold times up to 6 hr. The sulfur concentration was plotted as a function of temperature versus time at temperature. One NiCrAl sulfur study was performed on the same casting used by Browning to establish a base line between previous Auger Electron Spectroscopy (AES) results and the XPS results of this study. Sulfur surface segregation was similar for PWA 1480 and NiCrAl and reached a maximum of 30 at% at 800 to 850 C. Above 900 C the sulfur surface concentration decreased to about 3 at% at 1100 C. These results are contrasted to the minimal segregation observed for low sulfur hydrogen annealed materials which exhibit improved scale adhesion.

Jayne, D. T.; Smialek, J. L.

1993-01-01

453

High Temperature Mechanical Characterization and Analysis of Al2O3 /Al2O3 Composition  

NASA Technical Reports Server (NTRS)

Sixteen ply unidirectional zirconia coated single crystal Al2O3 fiber reinforced polycrystalline Al2O3 was tested in uniaxial tension at temperatures to 1400 C in air. Fiber volume fractions ranged from 26 to 31%. The matrix has primarily open porosity of approximately 40%. Theories for predicting the Young's modulus, first matrix cracking stress, and ultimate strength were applied and evaluated for suitability in predicting the mechanical behavior of Al2O3/Al2O3 composites. The composite exhibited pseudo tough behavior (increased area under the stress/strain curve relative to monolithic alumina) from 22 to 1400 C. The rule-of-mixtures provides a good estimate of the Young's modulus of the composite using the constituent properties from room temperature to approximately 1200 C for short term static tensile tests in air. The ACK theory provides the best approximation of the first matrix cracking stress while accounting for residual stresses at room temperature. Difficulties in determining the fiber/matrix interfacial shear stress at high temperatures prevented the accurate prediction of the first matrix cracking stress above room temperature. The theory of Cao and Thouless, based on Weibull statistics, gave the best prediction for the composite ultimate tensile strength.

Gyekenyesi, John Z.; Jaskowiak, Martha H.

1999-01-01

454

Magnetization anomaly of Nb3Al strands and instability of Nb3Al Rutherford cables  

SciTech Connect

Using a Cu stabilized Nb{sub 3}Al strand with Nb matrix, a 30 meter long Nb{sub 3}Al Rutherford cable was made by a collaboration of Fermilab and NIMS. Recently the strand and cable were tested. In both cases instability was observed at around 1.5 Tesla. The magnetization of this Nb{sub 3}Al strand was measured first using a balanced coil magnetometer at 4.2 K. Strands showed an anomalously large magnetization behavior around at 1.6 T, which is much higher than the usual B{sub c2} {approx} 0.5 Tesla (4.2 K) of Nb matrix. This result is compared with the magnetization data of short strand samples using a SQUID magnetometer, in which a flux-jump signal was observed at 0.5 Tesla, but not at higher field. As a possible explanation for this magnetization anomaly, the interfilament coupling through the thin Nb films in the strands is suggested. The instability problem observed in low field tests of the Nb{sub 3}Al Rutherford cables is attributed to this effect.

Yamada, Ryuji; /Fermilab; Kikuchi, Akihiro; /Tsukuba Magnet Lab; Wake, Masayoshi; /KEK, Tsukuba

2006-08-01

455

AlNb-Based Titanium Aluminide  

NASA Astrophysics Data System (ADS)

The microstructure of laser-tungsten inert gas hybrid welded Ti2AlNb-based joints and their tensile properties at room temperature were investigated in this paper. The results showed that good-quality joints could be obtained by hybrid welding process. The microstructure evolution was identified by means of optical microscopy, scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. The fusion zone mainly consisted of B2 phase due to the rapid cooling rate, as well as high Nb content. The phase compositions of the heat-affected zone were varied with different thermal cycles during the welding process. Tensile tests at room temperature showed that fracture tended to occur in the fusion zone, and the tensile strength and elongation were 950 MPa and 4.3%, respectively. The fracture mode was quasi-cleavage based on the observation of the fracture morphology.

Zhang, Kezhao; Liu, Ming; Lei, Zhenglong; Chen, Yanbin

2014-10-01

456

An elliptical wiggler beamline for the ALS  

SciTech Connect

A beamline for circularly polarized radiation produced by an elliptical wiggler has been designed at the ALS covering the broad energy range from 50 eV to 2000 eV. The rigorous theory of grating diffraction efficiency has been used to maximize transmitted flux. The nature of the elliptical wiggler insertion device creates a challenging optical problem due to the large source size in the vertical and horizontal directions. The requirement of high resolving power, combined with the broad tuning range and high heat loads complicate the design. These problems have been solved by using a variable included angle monochromator of the ``constant length`` type with high demagnification onto its entrance slit, and cooled optics.

Martynov, V.V. [Lawrence Berkeley Lab., CA (United States)]|[Inst. of Microelectronics Technology, Chernogolovka (Russia); McKinney, W.R.; Padmore, H.A. [Lawrence Berkeley Lab., CA (United States)

1995-10-01

457

Thermal cycling of AlTiN- and AlTiON-coated hot work tool steels at elevated temperatures  

Microsoft Academic Search

The principle failure mechanism in thixoforming dies is thermal fatigue as the mechanical loading on the tooling is modest owing to a mushy feedstock. X32CrMoV33 hot work tool steel samples coated with AlTiN and AlTiON via Cathodic Arc Physical Vapour Deposition were submitted to thermal cycling under conditions which mimic thixoforming of steels. While the AlTiN and AlTiON coatings provide

Yucel Birol; Duygu ?sler

2011-01-01

458

27Al Multiple-Quantum MAS NMR of Mechanically Treated Bayerite (?-Al(OH) 3) and Silica Mixtures  

Microsoft Academic Search

Two-dimensional 27Al multiple-quantum magic angle spinning (MQMAS) NMR experiments are used to study mixtures of bayerite (?-Al(OH)3) with either silicic acid (SiO2.nH2O) or silica gel (SiO2) that have been ground together for varying lengths of time. This mechanical treatment produces changes in the 27Al MAS and MQMAS NMR spectra that correspond to the formation of new Al species. Mean values

Sharon E. Ashbrook; Kenneth J. D. MacKenzie; Stephen Wimperis

2001-01-01

459

Mg-Al Sapphirine and Ca-Al Hibonite-bearing Granulite Xenoliths from the Chyulu Hills Volcanic Field, Kenya  

Microsoft Academic Search

Basanites of the Chyulu Hills (Kenya Rift) contain mafic Mg-Al and Ca-Al granulite xenoliths. Their protoliths are interpreted as troctolitic cumulates; however, the original mineral assemblages were almost completely transformed by subsolidus reactions. Mg-Al granulites contain the minerals spinel, sapphirine, sillimanite, plagioclase, corundum, clinopyroxene, orthopyroxene and garnet, whereas Ca-Al granulites are characterized by hibonite, spinel, sapphirine, mullite, sillimanite, plagioclase, quartz,

A. ULIANOV; A. KALT

2006-01-01

460

Sintering, microstructure and properties of WC-FeAlB and WC-Ni3AlB composite materials  

Microsoft Academic Search

The effect of boron on microstructure and mechanical properties of the intermetallic matrix composites (WC-FeAl-B and WC-Ni3Al-B) were investigated. The results were compared with those obtained from WC-Co composite which had same binder volume fraction and fabricated under identical sintering conditions. Boron doped FeAl (FeooA14o) and NhAl alloys were selected as potential new alternative binders in place of cobalt for

Mehdi Ahmadian-Najafabadi

2005-01-01

461

The effect of Al content on the galvanic corrosion behaviour of coupled Ni\\/graphite and Ni–Al coatings  

Microsoft Academic Search

In this study, the corrosion behaviour of 75Ni\\/25graphite abradable coating and Ni–Al bonding coatings with different Al content were investigated with open circuit potential and polarization tests. The galvanic corrosion of the coupled Ni\\/graphite and Ni–Al coatings was studied by using a zero-resistance ammeter in 5wt% NaCl solution. The experimental results showed that the corrosion resistance of the Ni–Al coatings

Cunguan Xu; Lingzhong Du; Bin Yang; Weigang Zhang

2011-01-01

462

Atomistic calculations of hydrogen interactions with Ni3Al grain boundaries and Ni\\/Ni\\/Ni3Al interfaces  

Microsoft Academic Search

Embedded Atom Method (EAM) potentials have been developed for the Ni\\/Al\\/H system. The potentials have been fit to numerous properties of this system. For example, these potentials represent the structural and elastic properties of bulk Ni, Al, Ni3Al, and NiAl quite well. In addition the potentials describe the solution and migration behavior of hydrogen in both nickel and aluminum. A

M. I. Baskes; J. E. Angelo; N. R. Moody

1995-01-01

463

Adhesion, Atomic Structure, and Bonding at the Al2O3(0001)/Al(111) Interface: A First Principles Study  

E-print Network

Adhesion, Atomic Structure, and Bonding at the «­Al2O3(0001)/Al(111) Interface: A First Principles ), and bond character of the «­Al2O3(0001)/Al(111) interface. A total of six candidate interface structures, and have determined that a major contribution to bonding across the interface is simi- lar to what is found

Adams, James B

464

The Low-Lying States of AlCu and AlAg  

NASA Technical Reports Server (NTRS)

The singlet and triplet states of AlCu and AlAg below about 32 000/cm are studied using the internally contracted multireference configuration-interaction method. A more elaborate study of the X(sup 1)Sum(sup +) ground state of AlCu is undertaken using extended Gaussian basis sets, including the effect of inner-shell correlation and including a perturbational estimate of relativistic effects. Our best estimate of the spectroscopic constants (r(sub 0), DeltaG(sub 1/2), and D(sub 0)) for the X(sup 1)Sum(sup+) state with the experimental values in parentheses are: 4.416(4.420) a(sub 0), 295 (294) /cm, and 2.318 (2.315) eV. The calculations definitively assign the upper state in the observed transition at 14 892/cm to the lowest (sup 1)Prod state. The calculated spectroscopic constants and radiative lifetime for the (sup 1)Prod state are in good agreement with experiment. The calculations support the tentative assignments of Behm et al. for three band systems observed in the visible region between 25 000 and 28 000 / cm. However, the computed spectroscopic constants are in very poor agreement with those deduced from an analysis of the spectra. Analogous theoretical results for AlAg suggest that the (2)(sup 3)Prod, (3)(sup 3)Prod, and (3)(sup 1)Sum(sup +) states account for the bands observed, but not assigned, by Duncan and co-workers.

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Partridge, Harry

1994-01-01

465

Infiltration of Saffil alumina fiber with AlCu and AlSi alloys  

SciTech Connect

Currently there is a considerable scientific and technological interest in the composite materials, which a strong ceramic reinforcement is incorporated into a metal matrix (MMC) to tailor its properties for specific applications. Among the various techniques for fabricating MMC, the liquid metal infiltration process by means of a pressurized gas is an attractive fabrication route for near net shaped metal matrix composite and has been successfully used to fabricate Al, Mg and more recently, Ni and Ni aluminide matrix composites, which can be reinforced by SiC or Al[sub 2]O[sub 3] particles, whiskers, or short fibers. This paper describes the experimental technique used and presents an experimental investigation of the effects of the process parameters employed, such as the preform and melt temperatures, the volume fraction of fibers in the preform and the applied pressure upon the infiltration length of a chopped preform during a unidirectional infiltration aided by gas pressure casting. The experiments of the present w