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Sample records for acacia diversion dam

  1. Symbiotic diversity in the cosmopolitan genus Acacia

    Science.gov (United States)

    James K. Leary; Paul W. Singleton; Paul G. Scowcroft; Dulal Borthakur

    2006-01-01

    Acacia is the second largest genus within the Leguminosae, with 1352 species identified. This genus is now known to be polyphyletic and the international scientific community will presumably split Acacia into five new genera. This review examines the diversity of biological nitrogen fixation symbiosis within Acacia as a single genus. Due to its global importance, an...

  2. Diversity and frequency of Acacia spp . in three regions in the ...

    African Journals Online (AJOL)

    This study was carried out to assess the diversity and frequency of Acacia spp. and to determine the effect of soil texture on the frequency of Acacia spp. The study sites were selected after field visits to the Al Madinah, Aseer and Al Baha areas. The selection was done on the basis of the natural distribution and density of ...

  3. Genetic diversity in Kenyan populations of Acacia senegal (L.) willd ...

    African Journals Online (AJOL)

    Acacia senegal belongs to the subgenus, Aculeiferum. It is an African arid and semi arid zone multipurpose tree species, highly valued for gum arabic production, agroforestry and desertification control besides other multiple uses. Genetic variation and resulting variable groupings were assessed using combined ...

  4. 43 CFR 418.18 - Diversions at Derby Dam.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Diversions at Derby Dam. 418.18 Section... Operations and Management § 418.18 Diversions at Derby Dam. (a) Diversions of Truckee River water at Derby Dam must be managed to maintain minimum terminal flow to Lahontan Reservoir or the Carson River except...

  5. Genetic Diversity of Acacia mangium Seed Orchard in Wonogiri Indonesia Using Microsatellite Markers

    Directory of Open Access Journals (Sweden)

    VIVI YUSKIANTI

    2012-09-01

    Full Text Available Genetic diversity is important in tree improvement programs. To evaluate levels of genetic diversity of first generation Acacia mangium seedling seed orchard in Wonogiri, Central Java, Indonesia, three populations from each region of Papua New Guinea (PNG and Queensland, Australia (QLD were selected and analyzed using 25 microsatellite markers. Statistical analysis showed that PNG populations have higher number of detected alleles and level of genetic diversity than QLD populations. This study provides a basic information about the genetic background of the populations used in the development of an A. mangium seed orchard in Indonesia.

  6. Genetic diversity in Kenyan populations of Acacia senegal (L.) willd ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-18

    Jul 18, 2008 ... diversity (Houston and Houston, 1993). So, the conclusion that spatial organization of local populations and the concomitant patterns of gene flow are important determinants of the level of genetic diversity within each population and of a species becoming genetically diffe- rentiated over its range (Yeh, ...

  7. Invasive Acacia longifolia induce changes in the microbial catabolic diversity of sand dunes

    DEFF Research Database (Denmark)

    Marchante, Elizabete; Kjøller, Annelise; Struwe, Sten

    2008-01-01

    and to the groups of amino acids and plant polymers were similar in both invaded areas and different in the non-invaded. The responses to tartaric acid, gallic acid, fumaric acid, Cistus litter, and Acacia litter were the same in long- and non-invaded areas, but different from recently invaded areas. The duration...... diversity. Five substrate groups were tested: amino acids, carbohydrates, carboxylic acids, plant litters, and plant polymers. CRP clearly discriminated between the three different areas. Respiratory responses to the individual substrates a-ketoglutaric acid, oxalic acid, starch, citric acid, and xylose...

  8. Evaluation of flora diversity and abundance in Awba Dam Tourism ...

    African Journals Online (AJOL)

    The study evaluated flora diversity and abundance in Awba Dam Tourism Centre, Ibadan, Nigeria. Complete enumeration of trees (>10cm diameter at breast height (dbh)), saplings, and small trees growing within 50m radius of the Awba dam was carried out. The percentage canopy cover of tree species (to the nearest 5%) ...

  9. Genetic and genomic diversity studies of Acacia symbionts in Senegal reveal new species of Mesorhizobium with a putative geographical pattern.

    Directory of Open Access Journals (Sweden)

    Fatou Diouf

    Full Text Available Acacia senegal (L Willd. and Acacia seyal Del. are highly nitrogen-fixing and moderately salt tolerant species. In this study we focused on the genetic and genomic diversity of Acacia mesorhizobia symbionts from diverse origins in Senegal and investigated possible correlations between the genetic diversity of the strains, their soil of origin, and their tolerance to salinity. We first performed a multi-locus sequence analysis on five markers gene fragments on a collection of 47 mesorhizobia strains of A. senegal and A. seyal from 8 localities. Most of the strains (60% clustered with the M. plurifarium type strain ORS 1032T, while the others form four new clades (MSP1 to MSP4. We sequenced and assembled seven draft genomes: four in the M. plurifarium clade (ORS3356, ORS3365, STM8773 and ORS1032T, one in MSP1 (STM8789, MSP2 (ORS3359 and MSP3 (ORS3324. The average nucleotide identities between these genomes together with the MLSA analysis reveal three new species of Mesorhizobium. A great variability of salt tolerance was found among the strains with a lack of correlation between the genetic diversity of mesorhizobia, their salt tolerance and the soils samples characteristics. A putative geographical pattern of A. senegal symbionts between the dryland north part and the center of Senegal was found, reflecting adaptations to specific local conditions such as the water regime. However, the presence of salt does not seem to be an important structuring factor of Mesorhizobium species.

  10. Genetic and genomic diversity studies of Acacia symbionts in Senegal reveal new species of Mesorhizobium with a putative geographical pattern.

    Science.gov (United States)

    Diouf, Fatou; Diouf, Diegane; Klonowska, Agnieszka; Le Queré, Antoine; Bakhoum, Niokhor; Fall, Dioumacor; Neyra, Marc; Parrinello, Hugues; Diouf, Mayecor; Ndoye, Ibrahima; Moulin, Lionel

    2015-01-01

    Acacia senegal (L) Willd. and Acacia seyal Del. are highly nitrogen-fixing and moderately salt tolerant species. In this study we focused on the genetic and genomic diversity of Acacia mesorhizobia symbionts from diverse origins in Senegal and investigated possible correlations between the genetic diversity of the strains, their soil of origin, and their tolerance to salinity. We first performed a multi-locus sequence analysis on five markers gene fragments on a collection of 47 mesorhizobia strains of A. senegal and A. seyal from 8 localities. Most of the strains (60%) clustered with the M. plurifarium type strain ORS 1032T, while the others form four new clades (MSP1 to MSP4). We sequenced and assembled seven draft genomes: four in the M. plurifarium clade (ORS3356, ORS3365, STM8773 and ORS1032T), one in MSP1 (STM8789), MSP2 (ORS3359) and MSP3 (ORS3324). The average nucleotide identities between these genomes together with the MLSA analysis reveal three new species of Mesorhizobium. A great variability of salt tolerance was found among the strains with a lack of correlation between the genetic diversity of mesorhizobia, their salt tolerance and the soils samples characteristics. A putative geographical pattern of A. senegal symbionts between the dryland north part and the center of Senegal was found, reflecting adaptations to specific local conditions such as the water regime. However, the presence of salt does not seem to be an important structuring factor of Mesorhizobium species.

  11. Excavation of the Surikamigawa dam diversion tunnel. Surikamigawa dam karihaisui tunnel kantsu

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, T.; Konno, T. (Ministry of Construction, Tokyo (Japan))

    1994-04-01

    A bypass tunnel construction has been completed at the Surikamigawa dam (Japan). This paper describes the summary of the construction. The full-swing dam construction work is scheduled to begin in 1995. The soils distributed near the dam site consist of lapillus tuff containing andesite-based light stones and tuff-based conglomerates containing large gravels. Excavation of the dam diversion tunnel has used a blasting method, and the tunnel construction has adopted an automatic tunnel cross section marking system and a non-electric explosion method. This marking system is a system to irradiate a laser beam onto the facing to depict excavation lines that realizes labor saving and high-accuracy excavation. The error at the tunnel completion was found 20 mm. The non-electric explosion method ignites a coated explosive layer with an impact wave, which is electrostatically safe, and reduces blasting vibration. Electric detonators have also been used because of using ANFO explosives. The result obtained from measurements of inner space displacement necessary for the blasting process has indicated that the area near the dam site consists of stable mountains. 6 figs., 4 tabs.

  12. 43 CFR 418.23 - Diversion of Rock Dam Ditch water.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Diversion of Rock Dam Ditch water. 418.23... Operations and Management § 418.23 Diversion of Rock Dam Ditch water. Project water may be diverted directly to Rock Dam Ditch from the Truckee Canal only when diversions cannot be made from the outlet works of...

  13. Diversity and frequency of Acacia spp. in three regions in the ...

    African Journals Online (AJOL)

    bismillha

    2012-06-28

    Jun 28, 2012 ... the Al Madinah, Aseer and Al Baha areas. The selection was done on the basis of the natural distribution and density of Acacia spp. Both Aseer and Al Baha are in the semiarid zone, and Al. Madinah is in the arid zone according to Emberger. Measurements of trees were carried out inside 0.1 ha sample ...

  14. Dams

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset �is generated from from the Vermont Dam Inventory (VDI). The VDI is managed by the VT DEC's Dam Safety and Hydrology Section and contains information...

  15. THE EFFECT OF INDIVIDUAL SELECTION FOR GENETIC DIVERSITY OF Acacia mangium SEEDLING SEED ORCHARD USING AFLP MARKERS

    Directory of Open Access Journals (Sweden)

    A. Y.P.B.C. Widyatmoko

    2006-07-01

    Full Text Available Establishment of seed orchard is aimed at producing good quality seeds which is an important activity for breeding program. Seed orchard is also a base population, thus its genetic diversity is depending on its design and composition (provenance, family and individual tree. Selection of an individual tree in seed orchard is needed for the enhancement of  retaining good-character trees. However, selection of individual tree can change the genetic diversity of seed orchard, and the degrees to which the genetic diversity will change depend on the used selection methods. In order to investigate the effects of selection methods, 4 simulations of selection methods based on height, diameter and stem performance of individual trees were used. The differences among the 4 methods were the ranking of individual trees those selected, and families and provenances those have been represented. Seedling seed orchard of Acacia mangium in Wonogiri, Central Java was used as materials. Analysis of genetic diversity was carried out using AFLP markers. Nine primer combinations were used to produce 1025 AFLP banding patterns. Among those banding patterns, only 109 were polymorphic markers. No significant effect of individual tree selection was revealed in this study. Even though the selection was done intensively, only 7.1% of genetic diversity was reduced. In other words, the selection activity did not reduce the genetic diversity of seed orchard significantly. The result is important for developing future tree improvement of A. mangium, including development of hybrid between A. mangium and A. auriculiformis.

  16. Changes in Land Use System and Environmental Factors Affect Arbuscular Mycorrhizal Fungal Density and Diversity, and Enzyme Activities in Rhizospheric Soils of Acacia senegal (L.) Willd.

    OpenAIRE

    Ndoye, Fatou; Kane, Aboubacry; Ngonkeu Mangaptché, Eddy Léonard; Bakhoum, Niokhor; Sanon, Arsène; Diouf, Diégane; Sy, Mame Ourèye; Baudoin, Ezékiel; Noba, Kandioura; Prin, Yves

    2012-01-01

    The responses of the soil microbial community features associated to the legume tree Acacia senegal (L.) Willd. including both arbuscular mycorrhizal fungal (AMF) diversity and soil bacterial functions, were investigated under contrasting environmental conditions. Soil samples were collected during dry and rainy seasons in two contrasting rainfall sites of Senegal (Dahra and Goudiry, in arid and semiarid zone, resp.). Soils were taken from the rhizosphere of A. senegal both in plantation and ...

  17. Acacia sieberiana Effects on Soil Properties and Plant Diversity in Songa Pastures, Rwanda

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    C. P. Mugunga

    2013-01-01

    Full Text Available Effects of A. sieberiana trees on soil properties and plant diversity were investigated in Songa pastures, Rwanda. Tree characteristics and crown architecture of A. sieberiana were studied. Soil properties were assessed and plants were identified under and away from tree crowns. Counts of individual plants/species were done only under tree crowns. Nitrogen, P, and K were analysed in the soil, grass, and A. sieberiana leaves. Plant diversity was determined using Simpson's diversity index. Data were subjected to ANOVA. Soil organic carbon (SOC, cation exchange capacity (CEC, Ca2+, N and pH, and plant diversity were higher in soils under tree canopies than in open areas. Tree leaves were significantly richer in N and poorer in P and K as compared to grasses. Tree crowns grew wider and horizontal and developed intertwined secondary branching, reducing light intensity to as low as 38% under tree canopies compared to the open pasture. At 3 trees/ha stocking, A. sieberiana trees shaded 0.18 ha and herbaceous plants and grasses unpalatable to livestock dominated under tree canopies. A tradeoff of A. sieberiana tree value versus the loss of palatable grass due to tree presence needs to be assessed to decide whether the trees should be included in pastures and if yes, the apporpriate stocking identified.

  18. Dams: impacts on the species diversity; Impacts des reservoirs sur la biodiversite

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Domingos de [Quebec Univ., Montreal, PQ (Canada). Dept. de Sciences Biologiques, Inst. de Sciences de l`Environnement

    1996-12-31

    Always you change one ecosystem, you have impacts on the species diversity. The work try to show some impacts of dams for hydroelectric power generation. First of all the author analyses the impacts on the habitats and ecosystems. He considers the problems on a variety of species, since plants and animals that living on the border of the river until the fishes, birds, invertebrates and the mammals. The example of 3 dams, La Grande, Opinaca and Caniapiseau, on Quebec, Canada, are used to give support to the work 14 refs., 1 tab.

  19. Downstream Migration of Masu Salmon Smolt at a Diversion Facility of Dam

    Science.gov (United States)

    Hayashida, K.; Nii, H.; Kasuga, K.; Watanabe, K.

    2014-12-01

    A diversion facility was installed on the upstream of Pirika Dam in Northern Japan that produced a downstream flow into the fishway, thus allowing the fish to migrate to the sea. On the other hand, if the flow rate in the river was more than 7.00 m 3/s (design flow rate of diversion facility), masu salmon smolt were concerned about accessing the dam reservoir, because the smolt can't migrate to the sea through the diversion facility unfortunately. Therefore, the downstream migration of smolt was investigated around the diversion facility. The PIT tag system and radio transmitters as the biotelemetry were used to determine 1) whether masu salmon smolt were able to migrate downstream through the diversion facility and fishway at Pirika Dam, 2) when the smolt started to migrate downstream, 3) whether the downstream migration of smolt were affected by the flow increase in the river. It was clarified that 88% of the smolt were able to enter the diversion facility, and then 81% of the smolt were able to access the fishway. It was also clarified that smolt downstream migration had two peaks in a day (5:00 and 18:00). During the study period, although the flow rate was in the 2.21 m3/s to 30.44 m3/s range (average 6.70 m3/s), it was revealed that the diversion facility has a satisfactory function for the downstream migration of smolt as presented above. The survey clarified the downstream migration behavior of masu salmon by using two types of biotelemetry equipment. PIT tag and radio transmitter were found to be very effective in tracking the behavior of small fish such as smolt. PIT tags, in particular, require very little operating cost, because once they are inserted in the fish, they do not need human labor for tracking. It is desirable to actively introduce the biotelemetry as tracking equipment when surveying the fish migration in the river.

  20. Diversity of microbial plankton across the Three Gorges Dam of the Yangtze River, China

    Directory of Open Access Journals (Sweden)

    Shang Wang

    2012-05-01

    Full Text Available The Three Gorges Dam (TGD of the Yangtze River, China, is one of the largest irrigation and hydroelectric engineering projects in the world. The effects of huge man-made projects like TGD on fauna and macrophyte are obvious, mainly through changes of water dynamics and flow pattern; however, it is less clear how microorganisms respond to such changes. This research was aimed to examine differences in microbial diversity at different seasons and locations (in front of and behind the TGD. In addition, differences between particle-attached and free-living communities were also examined. The community structures of total and potentially active microorganisms in the water columns behind and in front of the TGD were analyzed with the DNA- and RNA-based 16S rRNA gene phylogenetic approaches over three different seasons. Clone libraries of 16S rRNA genes were prepared after amplification from extracted DNA and, for some samples, after preparing cDNA from extracted rRNA. Differences were observed between sites at different seasons and between free-living and particle-attached communities. Both bacterial and archaeal communities were more diverse in summer than in winter, due to higher nutrient levels and warmer temperature in summer than in winter. Particle-attached microorganisms were more diverse than free-living communities, possibly because of higher nutrient levels and heterogeneous geochemical micro-environments in particles. Spatial variations in bacterial community structure were observed, i.e., the water reservoir behind the TGD (upstream hosted more diverse bacterial populations than in front of the dam (downstream, because of diverse sources of sediments and waters from upstream to the reservoir. These results have important implications for our understanding of responses of microbial communities to environmental changes in river ecosystems affected by dam construction.

  1. Composition, abundance and diversity of the Family Cichlidae in Oyan Dam, Ogun State, Nigeria

    Directory of Open Access Journals (Sweden)

    OLANIYI ALABA OLOPADE

    2014-10-01

    Full Text Available Olopade OA, Rufai OP. 2014. Composition, abundance and diversity of the Family Cichlidae in Oyan Dam, Ogun State, Nigeria. Biodiversitas 15: 195-199.This study was conducted to determine status of the family Cichlidae in Oyan Dam, Nigeria, during the wet and dry seasons of 2011. Samples were collected using multi-mesh gillnets ranging between 30 mm to 80 mm. Simpson's Diversity Index was used to determine the species richness, while dominance and evenness were given by Shannon's index. A total of 547 individuals were caught from Imala (S1 and Ibaro (S2 sites of the dam. Species collected include Sarotherodon galilaeus (42.60%, Oreochromis niloticus (17.92%, Tilapia zillii (25.41%, Hemichromis fasciatus (10.61% and Tilapia mariae (3.48%. Juveniles and sub-adults and adults were among the catch, the sizes were as big as 12.85±0.29cm SL, 109.22±6.00g BW in Tilapia zillii and small as 6.09±0.05cm SL and 8.07±0.15g BW in Hemichromis fasciatus. The diversity indexes showed that the diversity of Cichlids was lower in the two sites observed in Oyan Dam. The estimates of diversity indexes showed lower value for site 1 (0.284 than for site 2 (0.294; Simpson's diversity index was 0.716 for site 1 and 0.703 for site 2 while reciprocal indexes for site 1(3.521 was slightly lower than site 2 (3.367. Shannon-Wiener’s Index recorded in the site 1 (1.36 was slightly lower than site 2 (1.37. Pielou’s Index value recorded for site 1 was 0.845 and 0.852 for site 2. Sarotherodon galilaeus, Oreochromis niloticus, Tilapia zillii and Tilapia mariae exhibited a positive allometric growth pattern while only Hemichromis fasciatus showed a negative allometric growth.

  2. Assessment of Productivity Status Using Carlson’s TSI and Fish Diversity of Goronyo Dam, Sokoto State, Nigeria

    Directory of Open Access Journals (Sweden)

    Hassan Muhammad Maishanu

    2018-01-01

    Full Text Available Goronyo Dam is the largest lentic waterbody in Sokoto, it was constructed to serve as flood control and used for irrigation activities. The study was conducted to evaluate productivity status and fish diversity of Goronyo Dam in 2016. Water samples were collected monthly from the Dam at two sampling sites (Upstream and Downstream. Water samples were collected using sterilized sampling bottles and analyzed in the Laboratory for physicochemical variables and the diversity of fish was evaluated through the use of a structured questionnaire. Depth and transparency were the only variables that did not show any statistically significant difference between the months. Productivity status of the dam was evaluated using Carlson’s Trophic State Index. The downstream has high TSI value of 16.54 compared to upstream with 13.00. A diversity of fishes from the shows that 3 species were more abundant in the dam, these were; Mormyrops species, Alestes species and Clupeid species. Factors contributed to the survival of fish species were an abundance of water and plankton in the dam. While factors affecting the distribution of fish species were pollution and predation.

  3. Phylogenic analysis in Acacia senegal using AFLP molecular ...

    African Journals Online (AJOL)

    Amplified fragment length polymorphism (AFLP) DNA markers were used to characterize the genetic diversity and relationships in gum Arabic tree (Acacia senegal). Twenty eight samples of Acacia senegal collected from populations distributed throughout the Gum Arabic belt were tested in comparison with samples of ...

  4. 76 FR 25310 - Intent To Prepare an Environmental Impact Statement for the Zoar Levee and Diversion Dam, Dam...

    Science.gov (United States)

    2011-05-04

    ... dam. f. The cultural and historical significance of the Village of Zoar is well documented. The... community and a significant collection of early nineteenth century German folk architecture. Much of Zoar was documented in 1936 by the Historic American Building Survey (HABS). This study concluded that Zoar...

  5. Elucidating the native sources of an invasive tree species, Acacia pycnantha, reveals unexpected native range diversity and structure

    Science.gov (United States)

    Ndlovu, Joice; Richardson, David M.; Wilson, John R. U.; O'Leary, Martin; Le Roux, Johannes J.

    2013-01-01

    Background and Aims Understanding the introduction history of invasive plant species is important for their management and identifying effective host-specific biological control agents. However, uncertain taxonomy, intra- and interspecific hybridization, and cryptic speciation may obscure introduction histories, making it difficult to identify native regions to explore for host-specific agents. The overall aim of this study was to identify the native source populations of Acacia pycnantha, a tree native to south-eastern Australia and invasive in South Africa, Western Australia and Portugal. Using a phylogeographical approach also allowed an exploration of the historical processes that have shaped the genetic structure of A. pycnantha in its native range. Methods Nuclear (nDNA) and plastid DNA sequence data were used in network and tree-building analyses to reconstruct phylogeographical relationships between native and invasive A. pycnantha populations. In addition, mismatch distributions, relative rates and Bayesian analyses were used to infer recent demographic processes and timing of events in Australia that led to population structure and diversification. Key Results The plastid network indicated that Australian populations of A. pycnantha are geographically structured into two informally recognized lineages, the wetland and dryland forms, whereas the nuclear phylogeny showed little geographical structure between these two forms. Moreover, the dryland form of A. pycnantha showed close genetic similarity to the wetland form based on nDNA sequence data. Hybrid zones may explain these findings, supported here by incongruent phylogenetic placement of some of these taxa between nuclear and plastid genealogies. Conclusions It is hypothesized that habitat fragmentation due to cycles of aridity inter-dispersed with periods of abundant rainfall during the Pleistocene (approx. 100 kya) probably gave rise to native dryland and wetland forms of A. pycnantha. Although the

  6. Phylogeny of nodulation genes and symbiotic diversity of Acacia senegal (L.) Willd. and A. seyal (Del.) Mesorhizobium strains from different regions of Senegal.

    Science.gov (United States)

    Bakhoum, Niokhor; Galiana, Antoine; Le Roux, Christine; Kane, Aboubacry; Duponnois, Robin; Ndoye, Fatou; Fall, Dioumacor; Noba, Kandioura; Sylla, Samba Ndao; Diouf, Diégane

    2015-04-01

    Acacia senegal and Acacia seyal are small, deciduous legume trees, most highly valued for nitrogen fixation and for the production of gum arabic, a commodity of international trade since ancient times. Symbiotic nitrogen fixation by legumes represents the main natural input of atmospheric N2 into ecosystems which may ultimately benefit all organisms. We analyzed the nod and nif symbiotic genes and symbiotic properties of root-nodulating bacteria isolated from A. senegal and A. seyal in Senegal. The symbiotic genes of rhizobial strains from the two Acacia species were closed to those of Mesorhizobium plurifarium and grouped separately in the phylogenetic trees. Phylogeny of rhizobial nitrogen fixation gene nifH was similar to those of nodulation genes (nodA and nodC). All A. senegal rhizobial strains showed identical nodA, nodC, and nifH gene sequences. By contrast, A. seyal rhizobial strains exhibited different symbiotic gene sequences. Efficiency tests demonstrated that inoculation of both Acacia species significantly affected nodulation, total dry weight, acetylene reduction activity (ARA), and specific acetylene reduction activity (SARA) of plants. However, these cross-inoculation tests did not show any specificity of Mesorhizobium strains toward a given Acacia host species in terms of infectivity and efficiency as stated by principal component analysis (PCA). This study demonstrates that large-scale inoculation of A. senegal and A. seyal in the framework of reafforestation programs requires a preliminary step of rhizobial strain selection for both Acacia species.

  7. Final Independent External Peer Review Report for the Intake Diversion Dam Modification Lower Yellowstone Project, Montana Draft Supplement to the 26 April 2010 Environmental Assessment and Appendices

    Science.gov (United States)

    2013-02-08

    drop structures, embankments, and low-head dams for water diversion and flood control, including flood control projects in Contra Costa and Napa... counties , California. He has been a principal consultant on more than 150 small, earth-fill dams and reservoirs for the Vineyard Development Water...Intake Diversion Dam is located along the Lower Yellowstone River, approximately 18 miles downstream from the City of Glendive, Dawson County

  8. Numerical investigation of underground drain radius, depth and location on uplift pressure reduction (Case study: Tabriz diversion dam

    Directory of Open Access Journals (Sweden)

    Farzin Salmasi

    2016-06-01

    Full Text Available Water penetration from beneath of built structures on permeable soils causes uplift force along the contact of structure with foundation. This uplift force reduces hydraulic structure stability. Typically, these instabilities occur due to under-pressure development (uplift force, gradual inner degradation of foundation material (piping or sand boil phenomenon. Thus, it seems necessary to calculate the pressure applied to the contact surface of the dam. One method for preventing piping phenomenon, reduction in exit gradient as well as decrease of uplift force beneath diversion dams includes implementation of weep hole. This study aims to study the effect of radius, depth and location of pipe drains under stilling basin upon how much uplift force decreases. The benefit of this study in agricultural field for soil and water engineers is to have a safe design of lined canals, weirs or diversion dams. To do this, numerical simulation of Tabriz diversion dam with Geo-Studio software was carried out. Results showed that application of drain pipe under the structure reduced uplift force respect to without drain under the structure. Increasing of drain radius; caused reduction of uplift pressure more but increased of seepage flow slightly. Installation of drain in upper part of stilling basin had a tendency to decrease uplift pressure more. Existence of drain near the stilling basin bottom caused in more reducing of uplift pressure than of installation of it in deeper depth

  9. The impact of small irrigation diversion dams on the recent migration rates of steelhead and redband trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Weigel, Dana E.; Connolly, Patrick J.; Powell, Madison S.

    2013-01-01

    Barriers to migration are numerous in stream environments and can occur from anthropogenic activities (such as dams and culverts) or natural processes (such as log jams or dams constructed by beaver (Castor canadensis)). Identification of barriers can be difficult when obstructions are temporary or incomplete providing passage periodically. We examine the effect of several small irrigation diversion dams on the recent migration rates of steelhead (Oncorhynchus mykiss) in three tributaries to the Methow River, Washington. The three basins had different recent migration patterns: Beaver Creek did not have any recent migration between sites, Libby Creek had two-way migration between sites and Gold Creek had downstream migration between sites. Sites with migration were significantly different from sites without migration in distance, number of obstructions, obstruction height to depth ratio and maximum stream gradient. When comparing the sites without migration in Beaver Creek to the sites with migration in Libby and Gold creeks, the number of obstructions was the only significant variable. Multinomial logistic regression identified obstruction height to depth ratio and maximum stream gradient as the best fitting model to predict the level of migration among sites. Small irrigation diversion dams were limiting population interactions in Beaver Creek and collectively blocking steelhead migration into the stream. Variables related to stream resistance (gradient, obstruction number and obstruction height to depth ratio) were better predictors of recent migration rates than distance, and can provide important insight into migration and population demographic processes in lotic species.

  10. Two invasive acacia species secure generalist pollinators in invaded communities

    Science.gov (United States)

    Montesinos, Daniel; Castro, Sílvia; Rodríguez-Echeverría, Susana

    2016-07-01

    Exotic entomophilous plants need to establish effective pollinator interactions in order to succeed after being introduced into a new community, particularly if they are obligatory outbreeders. By establishing these novel interactions in the new non-native range, invasive plants are hypothesised to drive changes in the composition and functioning of the native pollinator community, with potential impacts on the pollination biology of native co-flowering plants. We used two different sites in Portugal, each invaded by a different acacia species, to assess whether two native Australian trees, Acacia dealbata and Acacia longifolia, were able to recruit pollinators in Portugal, and whether the pollinator community visiting acacia trees differed from the pollinator communities interacting with native co-flowering plants. Our results indicate that in the invaded range of Portugal both acacia species were able to establish novel mutualistic interactions, predominantly with generalist pollinators. For each of the two studied sites, only two other co-occurring native plant species presented partially overlapping phenologies. We observed significant differences in pollinator richness and visitation rates among native and non-native plant species, although the study of β diversity indicated that only the native plant Lithodora fruticosa presented a differentiated set of pollinator species. Acacias experienced a large number of visits by numerous pollinator species, but massive acacia flowering resulted in flower visitation rates frequently lower than those of the native co-flowering species. We conclude that the establishment of mutualisms in Portugal likely contributes to the effective and profuse production of acacia seeds in Portugal. Despite the massive flowering of A. dealbata and A. longifolia, native plant species attained similar or higher visitation rates than acacias.

  11. Species diversity and ecological studies Euglenophyta in the Zayandeh Rood lake dam

    Directory of Open Access Journals (Sweden)

    Masoumeh Shams

    2010-07-01

    Full Text Available Zayandeh Rood Lake, as the largest Isfahan natural Lake, is located in the west of Isfahan city with the area of about 48 km2. Sampling of Euglenophyta was done in four stations from August 2005 through June 2006. Ecological factors such as pH, EC, salinity, temperature and various nutrients were measured. A total of 4 genus and 9 species were identified in this lake. Euglena proxima Dang., Phacus caudatus var. ovalis Drez. and Trachelomonas robusta Swir., showed high density 1420, 952, 2380 cell/cm3, respectively. In this lake density of Euglenophyta increased in warm seasons because of high ions such as nitrate and phosphate. Based upon algal flora results, Zayandeh Rood dam lake could be regarded as an oligo-mesotrophic lake.

  12. Dam removal: Listening in

    Science.gov (United States)

    Foley, M. M.; Bellmore, J. R.; O'Connor, J. E.; Duda, J. J.; East, A. E.; Grant, G. E.; Anderson, C. W.; Bountry, J. A.; Collins, M. J.; Connolly, P. J.; Craig, L. S.; Evans, J. E.; Greene, S. L.; Magilligan, F. J.; Magirl, C. S.; Major, J. J.; Pess, G. R.; Randle, T. J.; Shafroth, P. B.; Torgersen, C. E.; Tullos, D.; Wilcox, A. C.

    2017-07-01

    Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

  13. Design of Environmental Flows Below Diversion Hydropower Dams: Is There Benefit to Advanced Streamflow Prediction in Sparse Data Landscapes?

    Science.gov (United States)

    Kibler, K. M.; Alipour, M.

    2017-12-01

    Diversion hydropower has been shown to significantly alter river flow regimes by dewatering diversion bypass reaches. Data scarcity is one of the foremost challenges to establishing environmental flow regimes below diversion hydropower dams, especially in regions of sparse hydro-meteorological observation. Herein, we test two prediction strategies for generating daily flows in rivers developed with diversion hydropower: a catchment similarity model, and a rainfall-runoff model selected by multi-objective optimization based on soft data. While both methods are designed for ungauged rivers embedded within large regions of sparse hydrologic observation, one is more complex and computationally-intensive. The objective of this study is to assess the benefit of using complex modeling tools in data-sparse landscapes to support design of environmental flow regimes. Models were tested in gauged catchments and then used to simulate a 28-year record of daily flows in 32 ungauged rivers. After perturbing flows with the hydropower diversion, we detect alteration using Indicators of Hydrologic Alteration (IHA) metrics and compare outcomes of the two modeling approaches. The catchment similarity model simulates low flows well (Nash-Sutcliff efficiency (NSE) = 0.91), but poorly represents moderate to high flows (overall NSE = 0.25). The multi-objective rainfall-runoff model performs well overall (NSE = 0.72). Both models agree that flow magnitudes and variability consistently decrease following diversion as temporally-dynamic flows are replaced by static minimal flows. Mean duration of events sustained below the pre-diversion Q75 and mean hydrograph rise and fall rates increase. While we see broad areas of agreement, significant effects and thresholds vary between models, particularly in the representation of moderate flows. Thus, use of simplified streamflow models may bias detected alterations or inadequately characterize pre-regulation flow regimes, providing inaccurate

  14. Wood Quality of Acacia Hybrid and Second-Generation Acacia mangium

    OpenAIRE

    Ismail Jusoh; Farawahida Abu Zaharin; Nur Syazni Adam

    2013-01-01

    Two new tree variants, namely Acacia hybrid and second-generation Acacia mangium, have been introduced in plantation forests in Sarawak, Malaysia, and their wood qualities were examined. The mean basic density of Acacia hybrid was comparable with Acacia mangium. However basic density and strength properties of second-generation A. mangium were significantly lower compared to Acacia hybrid. The mean fibre length and fibre wall thickness in the hybrid were found to be greater than that of secon...

  15. Equations for predicting the biomass of Acacia cyclops and Acacia ...

    African Journals Online (AJOL)

    A forest inventory was carried out in coastal areas infested by the alien tree species Acacia cyclops and A. saligna on the West Coast, Agulhas and Eastern ... For practical reasons, it was recommended to use basal area and squared basal area as predictors and to ignore commercial stem length as independent variable.

  16. Active Heat Injection to Investigate Seepage Conditions Along the Interface Between a Concrete Diversion Sluiceway and Earthen Embankment Dam

    Science.gov (United States)

    Ringeri, A.; Butler, K. E.; MacQuarrie, K. T. B.

    2016-12-01

    The interface between embankment dams and adjoining hydraulic structures are regions which can give rise to seepage defects. A field experiment was conducted at the Mactaquac Generating Station in New Brunswick, Canada using active thermometry to investigate seepage conditions along the interface of a diversion sluiceway and earth embankment. The method involved monitoring the time evolution of temperature following the injection of a controlled heat pulse from a subsurface heat cable acting as a line source. Transient anomalies in the induced temperature field can result from the aberration of thermal properties and flow conditions which accompany defects. An industrial heat trace cable and distributed temperature sensing (DTS) fibre optic cable were installed in two parallel, 42 m deep, sub-vertical boreholes separated by 3 m and offset 0.5 m from the core-concrete interface. The heat and DTS cables were installed in the upstream and downstream boreholes respectively. Heat was injected as a box car function at a constant rate of 78.72 W/m for 51 d while the DTS cable, with a 20 cm sampling resolution, was averaged over 10 min at 30 min intervals for 300 d. The DTS cable successfully detected temperature changes induced by the upstream heat pulse. A coherent temperature response occurred along a 13 m section of deep fibre, where mean peak temperatures rose 1.59 ± 0.03 °C above ambient temperatures with an average time lag of 8.2 d following the end of the heating cycle. Two temperature anomalies above this region coincided with the position of the water table and the location of a previously detected fibre break. The method appears to be particularly useful in seepage surveillance of the deeper regions of the interface. Further analysis is required to remove the influence of seasonal temperatures on the heat pulse response at shallow depths.

  17. ACTIVITIES OF ACACIA NILOTICA EXTRACTS

    African Journals Online (AJOL)

    DR. AMINU

    Bajopas Volume 7 Number 1 June, 2014. Table 7: Antibacterial Activity of Leaf Extracts of Acacia nilotica. Key: PER = Perfloxacin, REC = Recophin, 0 = No Activity. Diameter of Zones of Inhibition (mm)/ Extracts Concentration (µg/disc). Bacterial. Isolates. Ethanol. Methanol. Chloroform. Petroleum. Ether. Chloroform. Water.

  18. Acacia Gender Learning and Capacity Strengthening | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This project will serve a dual purpose: to develop a process of learning and reflection on gender within IDRC's Acacia (Communities and the Information Society in Africa) program initiative; and to undertake an evaluation of Acacia's gender strategy. This will be accomplished in three phases. During the preparatory phase, ...

  19. Morphological and anatomical response of Acacia ehrenbergiana ...

    African Journals Online (AJOL)

    ajl user 3

    2012-02-20

    Feb 20, 2012 ... The response of Acacia ehrenbergiana Hayne and Acacia tortilis (Forssk) Haynes subspp. raddiana seedlings to 100, 50 and 25% field capacity (FC) watering regimes was studied to determine their morphological and anatomical behaviour. Both species responded morphologically as well as anatomically ...

  20. Repeated flood disturbance enhances rotifer dominance and diversity in a zooplankton community of a small dammed mountain pond

    Czech Academy of Sciences Publication Activity Database

    Gabaldón, Carmen; Devetter, Miloslav; Hejzlar, Josef; Šimek, Karel; Znachor, Petr; Nedoma, Jiří; Seďa, Jaromír

    2017-01-01

    Roč. 76, č. 2 (2017), s. 292-304 ISSN 1129-5767 R&D Projects: GA ČR(CZ) GA15-24309S; GA ČR(CZ) GA13-00243S Institutional support: RVO:60077344 Keywords : flood events * repeated disturbance * dammed humic pond * growth rate * diapause Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.451, year: 2016

  1. Comparison of soil properties under tropical Acacia hybrid ...

    African Journals Online (AJOL)

    Despite the common use of Acacia species in Vietnam, few studies have examined changes to total soil nitrogen (TN) and total soil carbon (TC) following the planting of Acacia mangium × Acacia auriculiformis (Acacia hybrid) plantations (AH) on formerly eroded and degraded soils. We compared the impact of AH with ...

  2. Breeding Strategy of Acacia Hybrid (Acacia mangium × A. auriculiformis) to Increase Forest Plantation Productivity in Indonesia

    OpenAIRE

    Sri Sunarti; Mohamad Na'iem; Eko Bhakti Hardiyanto; Sapto Indrioko

    2013-01-01

    Acacia hybrid (Acacia mangium× A.auriculiformis) shows better growth and wood properties, and tolerance to pest and disease. Currently, acacia hybrid breeding strategy was developed through naturally hybrid selected from trees grown in plantation. However, mass propagation of acacia hybrid using such kind of strategy was not satisfied due to ageing effect. This study was aimed to develop a new acacia hybrid breeding strategy using controlled pollination hybridization technique. The strategy w...

  3. Karakteristik Serat Kayu Hibrid Acacia Auriculiformis X Acacia Mangium Sebagai Bahan Baku Pulp

    OpenAIRE

    Sunarti, Sri; Praptoyo, Harry; Nirsatmanto, Arif

    2016-01-01

    Acacia auriculiformis x Acacia mangium hybrid (Aa x Am) is a promising Acacia hybrid for pulp. Wood properties of the hybrid have been reported for their physical and chemical characteristics, but the fiber characteristics have not been investigated. This study was aimed to investigate the fiber characteristics of the hybrid. Wood samples were collected from three years old of Aa x Am hybrid trees planted in a hybrid seed orchard. For comparison, wood sample from other three species: A. mangi...

  4. Ecohydrology of a Dammed Amazon

    Science.gov (United States)

    Timpe, K. A.; Kaplan, D. A.

    2016-12-01

    reduced and baseflows and flow reversals are increased), however the impacts of HA on ecological function can vary greatly between watersheds. Future interdisciplinary research to develop flow-ecology relationships is needed to improve dam management in this mega-diverse region.

  5. Breeding Strategy of Acacia Hybrid (Acacia mangium × A. auriculiformis to Increase Forest Plantation Productivity in Indonesia

    Directory of Open Access Journals (Sweden)

    Sri Sunarti

    2013-08-01

    Full Text Available Acacia hybrid (Acacia mangium× A.auriculiformis shows better growth and wood properties, and tolerance to pest and disease. Currently, acacia hybrid breeding strategy was developed through naturally hybrid selected from trees grown in plantation. However, mass propagation of acacia hybrid using such kind of strategy was not satisfied due to ageing effect. This study was aimed to develop a new acacia hybrid breeding strategy using controlled pollination hybridization technique. The strategy was developed through a series of research: flowering, crossing, hybrid identification, clone multiplication, and clonal test. The results of study showed that the series of research for developing acacia hybrid breeding strategy was achieved. Flowering time synchronization provided a high probability for the success of controlled pollination hybridization. Leaves taxonomy at seedling stage revealed to be an efective way to identify acacia hybrid with acuracy of 92.2%. The acacia hybrid was succesfully propagated using shoot cutting at rate of 78.1%. The best selected clones of acacia hybrid outperformed in height growth at rates of 17.28% over to superior pure parents, which is equivalent to the estimated stand productivity at around 48 m3 ha-1 y-1. The series of research provided a new effective and efficient breeding strategy for acacia hybrid.Keywords: Acacia auriculiformis,  Acacia mangium, acacia hybrid, controlled pollination, breeding strategyDOI: 10.7226/jtfm.19.2.128

  6. Pharmacognostic Evaluation of the Bark of Acacia suma Roxb ...

    African Journals Online (AJOL)

    Methods: The macroscopic and microscopic features of the bark were studied, including the use of powder microscopy with the aid of ... The genus Acacia comprises about 1200 species, indigenous to tropical and subtropical regions, but found throughout the world [2]. Acacia suma Roxb var. Acacia polyacantha Willd is a ...

  7. Dam Safety Concepts

    NARCIS (Netherlands)

    Duricic, J.

    2014-01-01

    The majority of dams constructed in the world are dams that can be categorized as embankment dams. Throughout history we can point to many failures of dams, and embankment dams in particular. Nowadays it is clear that the goal to construct stable dams has not been achieved, even with advanced

  8. Repeated flood disturbance enhances rotifer dominance and diversity in a zooplankton community of a small dammed mountain pond

    Directory of Open Access Journals (Sweden)

    Carmen Gabaldón

    2016-12-01

    Full Text Available The zooplankton community in a relatively small and mountain pond was studied during the spring growing season. To investigate which factors operate in the community structure, we explored several physical conditions, such as high inflows, and the biotic dynamics of the main zooplankton groups (i.e., rotifers, cladocerans and copepods.  Two extreme flood events occurred during the investigated period and caused dramatic changes in physical conditions and reduction of the planktonic community abundances. The short period between both high-flow events was enough for the recovery of microplankton, but not for the metazoan zooplankton. Our results are in agreement with the common situation in which high flood events commonly favour rotifers over crustaceans, likely due to rotifer species have great colonization ability and grow faster. However, we found that the dominance of rotifers over crustaceans in our system is evidenced by an extremely, unusual high ratio between their abundances.  We observed that, at the time of the great floods, crustacean abundances as well as rotifer populations notably decreased until near zero values. Although rotifer abundance began declining before high floods, the decrease was particularly notable when the great flood happened.  Our results evidenced that i dilution rate and temperature were the main drivers which are operating in the structure of the zooplankton community; and ii no negative biotic interactions were detected between large and small cladocerans and rotifers. Additionally, we found surprisingly that a repeated disturbance caused by high flood events does increase the species diversity of rotifers. Finally, our study also detected some cues which may indicate that diapausing egg bank is also playing an important role in the zooplankton community, favouring the dominance of rotifers; however, this phenomenon deserves further studies. 

  9. Genetic improvement of tropical acacias: achievements and ...

    African Journals Online (AJOL)

    The potential for genetic improvement in form traits and wood properties has also been demonstrated. Genetic improvement objectives must now give heavy weighting to improving disease resistance and tolerance. Ganoderma root rot and Ceratocystis stem wilt have destroyed large areas of acacia plantations in Indonesia ...

  10. A photographic guide to Acacia koa defects

    Science.gov (United States)

    Eini C. Lowell; Janice K. Wiedenbeck; Betsy S. Porterfield

    2013-01-01

    Acacia koa (A. Gray), native to the Hawaiian Islands, has both cultural and economic significance. Koa wood is world-renowned for its extensive use in furniture, tone wood for musical instruments, and other items of cultural importance. Old-growth koa is decreasing in supply, yet dead and dying koa is still being harvested for manufacture of...

  11. Koa (Acacia koa) ecology and silviculture

    Science.gov (United States)

    Patrick J. Baker; Paul G. Scowcroft; John J. Ewel

    2009-01-01

    Koa (Acacia koa) is a tree species endemic to Hawaii that is of immense ecological and economic importance. This species has been mined from local forests for its wood for more than 100 years, and extensive areas of koa-dominated forests have been converted to grazing lands. Today, in recognition of the great importance and value of koa and the...

  12. Do cardinal directions in different Acacia tree species affect biological activities of bruchid beetle, Bruchidius buettikeri Decelle (Bruchidae: Coleoptera), in Riyadh Region, Saudi Arabia.

    Science.gov (United States)

    Aldawood, A S

    2009-12-15

    Biological activities of bruchid beetle: Bruchidius buettikeri Decelle (Bruchidae: Coleoptera) were studied in four cardinal directions of Acacia tree species in Huraimila and Salbouk. In Huraimila, two species of Acacia; A. grrrardii, subspecies A. g. negevensis (Iraqi) and A. g. nagednsis (Najdi); and A. ehrenbergiana (Salam) were sampled. In Salbouk, A. tortilis radiana (Samar) was sampled. No significant differences were observed for entrance and exit holes per pod and beetles emergence until 45 days on four cardinal directions of different Acacia tree species, except for entrance holes at Dam and Farm locations on Najdi in Huraimila. However, greater activities were observed in south and east direction in farm locations whereas, in the valley (Abu Gatada, Alyata and Dam locations) more bruchid activities were observed in north and south on Najdi and samar while east and west on Iraqi. Moreover, activities were greater on Acacia trees with greater number of seed per pod. Greater bruchid infestation per pod was found on East direction in the farm locations but in the valley locations no distinct trend was observed. Results showed a significant, positive correlation between bruchid activities and temperature but similar strength negative correlation was observed for rest of various abiotic factors. Moreover, a strong positive correlation was recorded between neonate entrance and number of beetle emergence.

  13. Characteristics Of Fiber From The Wood Of Acacia Auriculiformis X Acacia Mangium Hybrid With Regard To Pulp

    OpenAIRE

    Sunarti, Sri; Praptoyo, Harry; Nirsatmanto, Arif

    2016-01-01

    Acacia auriculiformis x Acacia mangium hybrid (Aa x Am) is a promising Acacia hybrid for pulp. Wood properties of the hybrid have been reported for their physical and chemical characteristics, but the fiber characteristics have not been investigated. This study was aimed to investigate the fiber characteristics of the hybrid. Wood samples were collected from three years old of Aa x Am hybrid trees planted in a hybrid seed orchard. For comparison, wood sample from other three species: A. mangi...

  14. Design and Construction of Dams, Reservoirs, and Balancing Lakes

    International Nuclear Information System (INIS)

    Lemperiere, F.

    2003-01-01

    The general data presented in sections two and three gives an idea of the extreme diversity of the millions of very large or very small dams worldwide. Dam design and construction methods for the most usual types of large dams are presented and justified in section four. The possibility and usefulness of building as many dams in the 21. century as have been built in the 20. is analyzed in section six. (author)

  15. NRC inventory of dams

    International Nuclear Information System (INIS)

    Lear, G.E.; Thompson, O.O.

    1983-01-01

    The NRC Inventory of Dams has been prepared as required by the charter of the NRC Dam Safety Officer. The inventory lists 51 dams associated with nuclear power plant sites and 14 uranium mill tailings dams (licensed by NRC) in the US as of February 1, 1982. Of the 85 listed nuclear power plants (148 units), 26 plants obtain cooling water from impoundments formed by dams. The 51 dams associated with the plants are: located on a plant site (29 dams at 15 plant sites); located off site but provide plant cooling water (18 dams at 11 additional plant sites); and located upstream from a plant (4 dams) - they have been identified as dams whose failure, and ensuing plant flooding, could result in a radiological risk to the public health and safety. The dams that might be considered NRC's responsibility in terms of the federal dam safety program are identified. This group of dams (20 on nuclear power plant sites and 14 uranium mill tailings dams) was obtained by eliminating dams that do not pose a flooding hazard (e.g., submerged dams) and dams that are regulated by another federal agency. The report includes the principal design features of all dams and related useful information

  16. Modeling the capacity of riverscapes to support beaver dams

    Science.gov (United States)

    Macfarlane, William W.; Wheaton, Joseph M.; Bouwes, Nicolaas; Jensen, Martha L.; Gilbert, Jordan T.; Hough-Snee, Nate; Shivik, John A.

    2017-01-01

    The construction of beaver dams facilitates a suite of hydrologic, hydraulic, geomorphic, and ecological feedbacks that increase stream complexity and channel-floodplain connectivity that benefit aquatic and terrestrial biota. Depending on where beaver build dams within a drainage network, they impact lateral and longitudinal connectivity by introducing roughness elements that fundamentally change the timing, delivery, and storage of water, sediment, nutrients, and organic matter. While the local effects of beaver dams on streams are well understood, broader coverage network models that predict where beaver dams can be built and highlight their impacts on connectivity across diverse drainage networks are lacking. Here we present a capacity model to assess the limits of riverscapes to support dam-building activities by beaver across physiographically diverse landscapes. We estimated dam capacity with freely and nationally-available inputs to evaluate seven lines of evidence: (1) reliable water source, (2) riparian vegetation conducive to foraging and dam building, (3) vegetation within 100 m of edge of stream to support expansion of dam complexes and maintain large colonies, (4) likelihood that channel-spanning dams could be built during low flows, (5) the likelihood that a beaver dam is likely to withstand typical floods, (6) a suitable stream gradient that is neither too low to limit dam density nor too high to preclude the building or persistence of dams, and (7) a suitable river that is not too large to restrict dam building or persistence. Fuzzy inference systems were used to combine these controlling factors in a framework that explicitly also accounts for model uncertainty. The model was run for 40,561 km of streams in Utah, USA, and portions of surrounding states, predicting an overall network capacity of 356,294 dams at an average capacity of 8.8 dams/km. We validated model performance using 2852 observed dams across 1947 km of streams. The model showed

  17. The Complete Sequence of the Acacia ligulata Chloroplast Genome Reveals a Highly Divergent clpP1 Gene.

    Directory of Open Access Journals (Sweden)

    Anna V Williams

    Full Text Available Legumes are a highly diverse angiosperm family that include many agriculturally important species. To date, 21 complete chloroplast genomes have been sequenced from legume crops confined to the Papilionoideae subfamily. Here we report the first chloroplast genome from the Mimosoideae, Acacia ligulata, and compare it to the previously sequenced legume genomes. The A. ligulata chloroplast genome is 174,233 bp in size, comprising inverted repeats of 38,225 bp and single-copy regions of 92,798 bp and 4,985 bp [corrected]. Acacia ligulata lacks the inversion present in many of the Papilionoideae, but is not otherwise significantly different in terms of gene and repeat content. The key feature is its highly divergent clpP1 gene, normally considered essential in chloroplast genomes. In A. ligulata, although transcribed and spliced, it probably encodes a catalytically inactive protein. This study provides a significant resource for further genetic research into Acacia and the Mimosoideae. The divergent clpP1 gene suggests that Acacia will provide an interesting source of information on the evolution and functional diversity of the chloroplast Clp protease complex.

  18. Evaluation of Local Gum of Acacia polyacantha as a Suspending ...

    African Journals Online (AJOL)

    The local gum of Acacia polyacantha was evaluated as a suspending agent in metronidazole benzoate suspensions in comparison with Acacia senegal and NaCMC at concentration range of 1-4% (w/v). The resulting suspensions were evaluated for their sedimentation volume (%), degree of flocculation, rheology, ...

  19. Performance of Broilers Given Different Dietary Levels of Acacia ...

    African Journals Online (AJOL)

    The study was aimed at evaluating the seeds of a leguminous plant, Acacia sieberiana DC as an alternative source of dietary plant protein for broilers. Five experimental diets containing 0 (control), 5, 10, 15 and 20% Acacia sieberiana seeds (ASS) were formulated and fed to 5 groups of birds during starter (0 - 4 weeks), ...

  20. 21 CFR 172.780 - Acacia (gum arabic).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acacia (gum arabic). 172.780 Section 172.780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... exudate from stems and branches of trees of various species of the genus Acacia, family Leguminosae. (b...

  1. Enhancement of Human Cheek Skin Texture by Acacia Nilotica Bark ...

    African Journals Online (AJOL)

    HP

    Purpose: To evaluate the effect of a topical application of a cream formulation containing extract of. Acacia nilotica bark extract on human cheek skin texture. Methods: A cream containing 3 % concentrated extract of Acacia nilotica bark was developed by entrapping the extract in the internal aqueous phase of the cream ...

  2. Acacia plantations in Vietnam: Research and knowledge application ...

    African Journals Online (AJOL)

    Vietnam has established 1.1 million ha of acacia plantations for wood production, managed on 5- to 10-year rotation cycles. Nearly 50% of the resource is managed by small growers holding 1–5 ha woodlots. Acacia plantations have emerged as an important resource for supporting the rural economy and national export ...

  3. Antibacterial and Cytotoxic Activities of Acacia nilotica Lam ...

    African Journals Online (AJOL)

    Erah

    that had maximum bactericidal activity against all the tested isolates, but showed < 30 % host cell cytotoxicity. Conclusion: The lysate of Acacia nilotica ... cytotoxic effects on human cells. EXPERIMENTAL. Plant material. Acacia nilotica Lam .... a detergent that permeabilizes eukaryotic cells and results in HBMEC damage.

  4. In vitro propagation of Acacia hybrid through alginate-encapsulated ...

    African Journals Online (AJOL)

    Seed collected from Acacia hybrid trees yields highly variable and poorly performing offspring and are not commonly used in regeneration. The present study described the incapsulation of Acacia hybrid shoots and axillary buds in the calcium alginate gel. The aim of the study was to evaluate the germination of the buds in ...

  5. Agroforestry potential of Acacia senegal in the rangelands of luwero ...

    African Journals Online (AJOL)

    Education, farm size, gender, occupation and ownership of domestic animals significantly influenced the local people's willingness to plant and manage A. se11egal trees. Therefore, local people need to be mobilised and educated on the agroforestry potential and conservation value of Acacia senegal. Key words: Acacia ...

  6. Investigation into nanocellulosics versus acacia reinforced acrylic films

    Science.gov (United States)

    Yunqiao Pu; Jianguo Zhang; Thomas Elder; Yulin Deng; Paul Gatenholm; Arthur J. Ragauskas

    2007-01-01

    Three closely related cellulosic acrylic latex films were prepared employing acacia pulp fibers, cellulose whiskers and nonocellulose balls and their respective strength properties were determined. Cellulose whisker reinforced composites had enhanced strength properties compared to the acacia pulp and nanoball composites. AFM analysis indicated that the cellulose...

  7. Pharmacognostic Evaluation of the Bark of Acacia suma Roxb ...

    African Journals Online (AJOL)

    Pharmacognostic Evaluation of the Bark of Acacia suma Roxb (Fabaceae). GK Dash, MS Abdullah, S Acharyya. Abstract. Purpose: To undertake the pharmacognostic evaluation of Acacia suma Roxb bark for the purpose of identification and differentiation from related species. Methods: The macroscopic and microscopic ...

  8. Antimicrobial Effects of Acacia nilotica and Vitex doniana on the ...

    African Journals Online (AJOL)

    This study was carried out to investigate the in vitro activity of the extracts of Acacia nilotica and Vitex doniana against Campylobacter jejuni, C. coli, and C. laridis isolated from sheep in Zaria and Kaduna. Water and ethanol crude extracts of Acacia nilotica and Vitex doniana were tested on the thermophilic Campylobacter ...

  9. Enhancement of Human Cheek Skin Texture by Acacia Nilotica Bark ...

    African Journals Online (AJOL)

    ... < 0.05) and the texture parameter of energy showed significant increase (p < 0.05). Conclusion: Our findings indicate that the cream containing 3 % Acacia nilotica bark extract possesses anti-aging effect and improves skin surface appearance.. Keywords: Acacia nilotica, Cream, Visioscan VC 98, Skin texture, Anti-aging ...

  10. Dams, Hydrology and Risk in Future River Management

    Science.gov (United States)

    Wegner, D. L.

    2017-12-01

    Across America there are over 80,000 large to medium dams and globally the number is in excess of 800,000. Currently there are over 1,400 dams and diversion structures being planned or under construction globally. In addition to these documented dams there are thousands of small dams populating watersheds. Governments, agencies, native tribes, private owners and regulators all have a common interest in safe dams. Often dam safety is characterized as reducing structural risk while providing for maximum operational flexibility. In the 1970's there were a number of large and small dam failures in the United States. These failures prompted the federal government to issue voluntary dam safety guidelines. These guidelines were based on historic information incorporated into a risk assessment process to analyze, evaluate and manage risk with the goal to improve the quality of and support of dam management and safety decisions. We conclude that historic and new risks need to be integrated into dam management to insure adequate safety and operational flexibility. A recent assessment of the future role of dams in the United States premises that future costs such as maintenance or removal beyond the economic design life have not been factored into the long-term operations or relicensing of dams. The converging risks associated with aging water storage infrastructure, multiple dams within watersheds and uncertainty in demands policy revisions and an updated strategic approach to dam safety. Decisions regarding the future of dams in the United States may, in turn, influence regional water planning and management. Leaders in Congress and in the states need to implement a comprehensive national water assessment and a formal analysis of the role dams play in our water future. A research and national policy agenda is proposed to assess future impacts and the design, operation, and management of watersheds and dams.

  11. Alpine dams

    Directory of Open Access Journals (Sweden)

    Alain Marnezy

    2009-03-01

    Full Text Available Les barrages-réservoirs de montagne ont été réalisés initialement dans les Alpes pour répondre à la demande d’énergie en période hivernale. Une certaine diversification des usages de l’eau s’est ensuite progressivement développée, en relation avec le développement touristique des collectivités locales. Aujourd’hui, la participation des ouvrages d’Électricité De France à la production de neige de culture représente une nouvelle étape. Dans les régions où les aménagements hydroélectriques sont nombreux, les besoins en eau pour la production de neige peuvent être résolus par prélèvements à partir des adductions EDF. Les gestionnaires de stations échappent ainsi aux inconvénients liés à la construction et à la gestion des « retenues collinaires ». Cette évolution, qui concerne déjà quelques régions alpines comme la haute Maurienne ou le Beaufortin, apparaît comme une forme renouvelée d’intégration territoriale de la ressource en eau.Mountain reservoirs were initially built in the Alps to meet energy needs in the winter. A certain diversification in the uses of water then gradually developed, related to tourism development in the local communities. Today, the use of facilities belonging to EDF (French Electricity Authority to provide water for winter resorts to make artificial snow represents a new phase. By taking water from EDF resources to supply snow-making equipment, resort managers are thus able to avoid the problems related to the construction and management of small headwater dams. This new orientation in the use of mountain water resources already affects a number of alpine regions such as the Upper Maurienne valley and Beaufortain massif and represents a renewed form of the territorial integration of water resources.

  12. Rehabilitation at Olympic Dam

    International Nuclear Information System (INIS)

    Chandler, W.P.; Middleton, B.A.

    1986-01-01

    Rehabilitation work on areas denuded of vegetation during the exploration phase of the Olympic Dam project was used to test various methods for regeneration of vegetation cover in the arid zone. The test work carried out on drill pads and access tracks has indicated that, with adequate site preparation, natural regeneration is the most economical and effective method to ensure post-operational stability of the affected land-forms. An on-going monitoring regime, utilising a computer data base, has been set up to allow year-to-year comparison of rehabilitation effectiveness. The database also provides a catalogue of initial colonising plants and a measure of variations in species diversity with time

  13. ANATOMICAL PROPERTIES AND FIBER DIMENSION OF PRICKLY ACACIA (Acacia nilotica L. FROM BALURAN NATIONAL PARK

    Directory of Open Access Journals (Sweden)

    Krisdianto Krisdianto

    2007-07-01

    Full Text Available Acacia nilotica (L. Willd. ex. Delile growing in Baluran National Park has dramatically altered the ecological balance of grasslands and thereby threatens the existence of local biodiversity. Prickly acacia is able to spread rapidly and remains uncontrollable. Baluran National Park authorization has been struggling to control this prickly acacia trees. One possible action that can be taken to encounter this problem is allowing wood based industries, and local people take advantages of this nilotica timber utilization. This paper studies the anatomical properties and fiber dimensions of nilotica timber and discusses the possible utilization of  nilotica timber.   This timber is characterized by dark brown heartwood which is clearly distinct from reddish brown color of sapwood. The denser cell wall shows attractively streaked in tangential surfaces. The length of  wood fiber decreases from pith toward periphery portion. Longitudinally, higher stem has shorter fiber. Nilotica wood has second class quality of fiber, which means its fiber is moderately thick with narrow lumen diameter. Due to small log diameter and branches, the nilotica timber is not recommended for construction material. The timber is suitable for carved and turnery products. Nilotica timber is suitable for charcoal manufacture and fuel wood due to its high calorific value.

  14. Dam removal: Listening in

    Science.gov (United States)

    Foley, Melissa M.; Bellmore, James; O'Connor, James E.; Duda, Jeff; East, Amy E.; Grant, Gordon G.; Anderson, Chauncey; Bountry, Jennifer A.; Collins, Mathias J.; Connolly, Patrick J.; Craig, Laura S.; Evans, James E.; Greene, Samantha; Magilligan, Francis J.; Magirl, Christopher S.; Major, Jon J.; Pess, George R.; Randle, Timothy J.; Shafroth, Patrick B.; Torgersen, Christian E.; Tullos, Desiree D.; Wilcox, Andrew C.

    2017-01-01

    Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (dam types, watershed conditions, and dam-removal methods in the U.S.

  15. Hoover Dam Learning Packet.

    Science.gov (United States)

    Bureau of Reclamation (Dept. of Interior), Washington, DC.

    This learning packet provides background information about Hoover Dam (Nevada) and the surrounding area. Since the dam was built at the height of the Depression in 1931, people came from all over the country to work on it. Because of Hoover Dam, the Colorado River was controlled for the first time in history and farmers in Nevada, California, and…

  16. Canadian dam safety conference

    International Nuclear Information System (INIS)

    1991-01-01

    A conference was held on the subject of dam safety in Canada. Sessions concerned assessment of existing dam safety under seismic loading, seismic analysis of concrete and embankment dams, selection of seismic criteria, landslides, risk analysis, and floods. Separate abstracts have been prepared for 24 papers presented at the conference

  17. Mechanics of slide dams

    International Nuclear Information System (INIS)

    Young, G.A.

    1970-01-01

    Studies which promote the use of nuclear energy for peaceful projects in engineering are sponsored by the Atomic Energy Commission under the Plowshare program. Specific projects being considered include the construction of harbors, canals, and dams. Of these projects, perhaps the most difficult to accomplish will be the latter. This paper which is in two parts considers the problems which are associated with the construction of slide dams with nuclear explosives. It examines first the characteristics of conventional earth and rock-fill dams which are based upon proven techniques developed after many years of experience. The characteristics of natural landslide dams are also briefly considered to identify potential problems that must be overcome by slide dam construction techniques. Second, the mechanics of slide dams as determined from small-scale laboratory studies are presented. It is concluded that slide dams can be constructed and that small-scale field tests and additional laboratory studies are justified. (author)

  18. Impact of the energy crop Jatropha curcas L. on the composition of rhizobial populations nodulating cowpea (Vigna unguiculata L.) and acacia (Acacia seyal L.).

    Science.gov (United States)

    Dieng, Amadou; Duponnois, Robin; Floury, Antoine; Laguerre, Gisèle; Ndoye, Ibrahima; Baudoin, Ezékiel

    2015-03-01

    Jatropha curcas, a Euphorbiaceae species that produces many toxicants, is increasingly planted as an agrofuel plant in Senegal. The purpose of this study was to determine whether soil priming induced by J. curcas monoculture could alter the rhizobial populations that nodulate cowpea and acacia, two locally widespread legumes. Soil samples were transferred into a greenhouse from three fields previously cultivated with Jatropha for 1, 2, and 15 years, and the two trap legumes were grown in them. Control soil samples were also taken from adjacent Jatropha-fallow plots. Both legumes tended to develop fewer but larger nodules when grown in Jatropha soils. Nearly all the nifH sequences amplified from nodule DNA were affiliated to the Bradyrhizobium genus. Only sequences from Acacia seyal nodules grown in the most recent Jatropha plantation were related to the Mesorhizobium genus, which was much a more conventional finding on A. seyal than the unexpected Bradyrhizobium genus. Apart from this particular case, only minor differences were found in the respective compositions of Jatropha soil versus control soil rhizobial populations. Lastly, the structure of these rhizobial populations was systematically imbalanced owing to the overwhelming dominance of a very small number of nifH genotypes, some of which were identical across soil types or even sites. Despite these weak and sparse effects on rhizobial diversity, future investigations should focus on the characterization of the nitrogen-fixing abilities of the predominant rhizobial strains. Copyright © 2014 Elsevier GmbH. All rights reserved.

  19. Tailings dams from the perspective of conventional dam engineering

    International Nuclear Information System (INIS)

    Szymanski, M.B.

    1999-01-01

    A guideline intended for conventional dams such as hydroelectric, water supply, flood control, or irrigation is used sometimes for evaluating the safety of a tailings dam. Differences between tailings dams and conventional dams are often substantial and, as such, should not be overlooked when applying the techniques or safety requirements of conventional dam engineering to tailings dams. Having a dam safety evaluation program developed specifically for tailings dams is essential, if only to reduce the chance of potential errors or omissions that might occur when relying on conventional dam engineering practice. This is not to deny the merits of using the Canadian Dam Safety Association Guidelines (CDSA) and similar conventional dam guidelines for evaluating the safety of tailings dams. Rather it is intended as a warning, and as a rationale underlying basic requirement of tailings dam emgineering: specific experience in tailings dams is essential when applying conventional dam engineering practice. A discussion is included that focuses on the more remarkable tailings dam safety practics. It is not addressed to a technical publications intended for such dams, or significantly different so that the use of conventional dam engineering practice would not be appropriate. The CDSA Guidelines were recently revised to include tailings dams. But incorporating tailings dams into the 1999 revision of the CDSA Guidelines is a first step only - further revision is necessary with respect to tailings dams. 11 refs., 2 tabs

  20. Host plant use by competing acacia-ants: mutualists monopolize while parasites share hosts.

    Science.gov (United States)

    Kautz, Stefanie; Ballhorn, Daniel J; Kroiss, Johannes; Pauls, Steffen U; Moreau, Corrie S; Eilmus, Sascha; Strohm, Erhard; Heil, Martin

    2012-01-01

    Protective ant-plant mutualisms that are exploited by non-defending parasitic ants represent prominent model systems for ecology and evolutionary biology. The mutualist Pseudomyrmex ferrugineus is an obligate plant-ant and fully depends on acacias for nesting space and food. The parasite Pseudomyrmex gracilis facultatively nests on acacias and uses host-derived food rewards but also external food sources. Integrative analyses of genetic microsatellite data, cuticular hydrocarbons and behavioral assays showed that an individual acacia might be inhabited by the workers of several P. gracilis queens, whereas one P. ferrugineus colony monopolizes one or more host trees. Despite these differences in social organization, neither of the species exhibited aggressive behavior among conspecific workers sharing a tree regardless of their relatedness. This lack of aggression corresponds to the high similarity of cuticular hydrocarbon profiles among ants living on the same tree. Host sharing by unrelated colonies, or the presence of several queens in a single colony are discussed as strategies by which parasite colonies could achieve the observed social organization. We argue that in ecological terms, the non-aggressive behavior of non-sibling P. gracilis workers--regardless of the route to achieve this social structure--enables this species to efficiently occupy and exploit a host plant. By contrast, single large and long-lived colonies of the mutualist P. ferrugineus monopolize individual host plants and defend them aggressively against invaders from other trees. Our findings highlight the necessity for using several methods in combination to fully understand how differing life history strategies affect social organization in ants.

  1. Comparative anticancer and antimicrobial activity of aerial parts of Acacia salicina, Acacia laeta, Acacia hamulosa and Acacia tortilis grown in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Mohamed F. Alajmi

    2017-12-01

    Full Text Available The standardized ethanol extract (EE of aerial parts of four Acacia species [A. salicina (ASEE, A. laeta (ALEE, A. hamulosa (AHEE, and A. tortilis (ATEE] were examined in order to compare their cytotoxic and antimicrobial activities. All the extracts were standardized by UPLC- PDA method using rutin as standard compound. The extracts ALEE, AHEE and ATEE were found to contain rutin along with several other phytoconstituents while rutin was absent in ASEE. All the extracts showed varying level of antimicrobial activity with zone of inhibition ranged from 11 to 21 mm against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The ALEE and ATEE showed relatively high antimicrobial potency (MIC = 0.2 to 1.6 mg mL−1 in comparison to other extracts. All the extracts were found to reduce the biofilm of P. aeruginosa PAO1 strain significantly in comparison to the untreated control. The cytotoxic property of ASEE, ALEE, AHEE, ATEE were evaluated against HepG2 (Liver, HEK-293 (Kidney, MCF-7 (Breast and MDA-MB 231 (Breast cancer cells. Of these, ALEE, AHEE and ATEE exhibited moderate cytotoxic property against human liver carcinoma cells (HepG2; IC50 = 46.2, 39.2 and 42.3 μg mL−1, respectively and breast cancer cell lines (MCF-7; IC50 = 57.2, 55.3 and 65.7 μg mL−1, respectively. The ATEE and ALEE showed moderate cytotoxicity against HEK-293 (kidney cells with IC50 = 49.1 and 53.5 μg mL−1, respectively. Since, Acacia species (A. laeta and A. hamulosa contains numerous polyphenols which might prove to be highly cytotoxic and antimicrobial agents, we suggest that these species can be further subjected to the isolation of more cytotoxic and antimicrobial compounds.

  2. Climate trends in the wood anatomy of Acacia sensu stricto (Leguminosae: Mimosoideae).

    Science.gov (United States)

    Warwick, Nigel W M; Hailey, Luke; Clarke, Kerri L; Gasson, Peter E

    2017-06-01

    This study investigates the structural diversity of the secondary xylem of 54 species of Acacia from four taxonomic sections collected across five climate regions along a 1200 km E-W transect from sub-tropical [approx. 1400 mm mean annual precipitation (MAP)] to arid (approx. 240 mm MAP) in New South Wales, Australia. Acacia sensu stricto ( s.s. ) is a critical group for understanding the effect of climate and phylogeny on the functional anatomy of wood. Wood samples were sectioned in transverse, tangential and radial planes for light microscopy and analysis. The wood usually has thick-walled vessels and fibres, paratracheal parenchyma and uniseriate and biseriate rays, occasionally up to four cells wide. The greater abundance of gelatinous fibres in arid and semi-arid species may have ecological significance. Prismatic crystals in chambered fibres and axial parenchyma increased in abundance in semi-arid and arid species. Whereas vessel diameter showed only a small decrease from the sub-tropical to the arid region, there was a significant 2-fold increase in vessel frequency and a consequent 3-fold decrease in the vulnerability index. Although the underlying phylogeny determines the qualitative wood structure, climate has a significant influence on the functional wood anatomy of Acacia s.s. , which is an ideal genus to study the effect of these factors. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  3. Tree invasion in a semi-arid savanna in Zimbabwe : seedling recruitment of Acacia karroo

    NARCIS (Netherlands)

    Chirara, C. (Chipangura)

    2001-01-01

    In this thesis Chirara reports on his study on the competitive interaction between savanna grasses and young tree seedlings of Acacia karroo, from hereon indicated as ' Acacia seedlings' . Acacia is one of the tree species that dominates savanna grassland in situations of overgrazing (bush

  4. Dams: Pros and Cons

    African Journals Online (AJOL)

    Steve

    Many Dams have been constructed in different parts of the world and for different purposes. While these dams have in most cases served the reason for their construction, the resultant environmental impact have been a subject of concern. The creation of a reservoir not only changes the ecology and hydrology of the ...

  5. Alkaline Pulping and Bleaching of Acacia auriculiformis Grown in Bangladesh

    OpenAIRE

    JAHAN, M. Sarwar; SABINA, Rowshan; RUBAIYAT, Arjumand

    2014-01-01

    The physical, chemical, and morphological characteristics of Acacia auriculiformis were evaluated in terms of its suitability for papermaking. The fiber length (1.1 mm) of A. auriculiformis in this study was within the range of tropical hardwoods. The lignin content in A. auriculiformis was 19.4% and a-cellulose 44.1%, which was within the range of other acacias, but that of extractives was higher. Soda, soda-AQ, and kraft processes were studied in pulping. Screened pulp yield was increased w...

  6. Acacia bark residues as filler in polypropylene composites

    Directory of Open Access Journals (Sweden)

    Ticiane Taflick

    2015-06-01

    Full Text Available AbstractLarge amounts of acacia bark residues are produced each day after tannin extraction with hot water, being generally burned. This by-product was chemically characterized and used as filler in polypropylene (PP composites, considering different particle sizes and concentrations. The materials produced by melt blending had their mechanical and thermal properties evaluated. It was verified that, even containing a significant amount of extractable compounds, the acacia bark particles can produce PP composites with higher impact properties, higher crystallization temperature and higher degradation temperature in comparison to the polymer matrix.

  7. Pengurangan Selip Pada Jalan Tanah Angkutan Kayu Acacia Mangium

    OpenAIRE

    Yuniawati

    2015-01-01

    Slip as one of the obstacles that affect the smooth hauling of Acacia wood Mangium. This study aimed to determine the use of auxiliary tools and do not use auxiliary tools on the occurrence of slip on a dirt road transportation acacia mangium and its influence on the productivity of hauling, cost of production and damage to the soil. Methods research is design and make auxiliary tools, test, measurement and analysis of data in the form of slip calculation, productivity, cost of production and...

  8. The acacia ants revisited: convergent evolution and biogeographic context in an iconic ant/plant mutualism.

    Science.gov (United States)

    Ward, Philip S; Branstetter, Michael G

    2017-03-15

    Phylogenetic and biogeographic analyses can enhance our understanding of multispecies interactions by placing the origin and evolution of such interactions in a temporal and geographical context. We use a phylogenomic approach-ultraconserved element sequence capture-to investigate the evolutionary history of an iconic multispecies mutualism: Neotropical acacia ants ( Pseudomyrmex ferrugineus group) and their associated Vachellia hostplants. In this system, the ants receive shelter and food from the host plant, and they aggressively defend the plant against herbivores and competing plants. We confirm the existence of two separate lineages of obligate acacia ants that convergently occupied Vachellia and evolved plant-protecting behaviour, from timid ancestors inhabiting dead twigs in rainforest. The more diverse of the two clades is inferred to have arisen in the Late Miocene in northern Mesoamerica, and subsequently expanded its range throughout much of Central America. The other lineage is estimated to have originated in southern Mesoamerica about 3 Myr later, apparently piggy-backing on the pre-existing mutualism. Initiation of the Pseudomyrmex / Vachellia interaction involved a shift in the ants from closed to open habitats, into an environment with more intense plant herbivory. Comparative studies of the two lineages of mutualists should provide insight into the essential features binding this mutualism. © 2017 The Author(s).

  9. Assessment of dam effects on streams and fish assemblages of the conterminous USA.

    Science.gov (United States)

    Cooper, Arthur R; Infante, Dana M; Daniel, Wesley M; Wehrly, Kevin E; Wang, Lizhu; Brenden, Travis O

    2017-05-15

    Despite the prevalence of damming as a global disturbance to river habitats, detailed reach-based assessments of the ecological effects of dams are lacking, particularly across large spatial extents. Using data from nearly 50,000 large dams, we assessed stream network fragmentation and flow alteration by large dams for streams of the conterminous USA. We developed 21 dam metrics characterizing a diversity of dam influences operating at both localized (e.g., distances-to-dams) and landscape scales (e.g., cumulative reservoir storage throughout stream networks) for every stream reach in the study region. We further evaluated how dams have affected stream fish assemblages within large ecoregions using more than 37,000 stream fish samples. Streams have been severely fragmented by large dams, with the number of stream segments increasing by 801% compared to free-flowing streams in the absence of dams and a staggering 79% of stream length is disconnected from their outlet (i.e., oceans and Great Lakes). Flow alteration metrics demonstrate a landscape-scale disturbance of dams, resulting in total upstream reservoir storage volumes exceeding estimated annual discharge volumes of many of the nation's largest rivers. Further, we show large-scale changes in fish assemblages with dams. Species adapted to lentic habitats increase with dams across the conterminous USA, while rheophils, lithophils, and intolerant fishes decrease with dams. Overall, fragmentation and flow alteration by dams have affected fish assemblages as much or more than other anthropogenic stressors, with dam effects generally increasing with stream size. Dam-induced stream fragmentation and flow alteration are critical natural resource issues. This study emphasizes the importance of considering dams as a landscape-scale disturbance to river habitats along with the need to assess differential effects that dams may have on river habitats and the fishes they support. Together, these insights are essential for

  10. Tailings dams safety - implications for the dam safety community

    International Nuclear Information System (INIS)

    Vick, S.G.

    1999-01-01

    In the context of the impact of privatization and globalization on traditional dam safety practice and the Canadian experience of the environmental dimension of dam failures, various aspects of tailings dam safety have much to offer the wider dam safety community. General design principles for tailings dams are not described, rather an attempt is made to frame some contemporary issues of tailings dam safety in ways that bring out their relevance in a broader dam safety context. Lessons applicable to future dam safety practice in related areas are examined, and the dam safety traditions of the mining, hydroelectric and related industries in Canada are brought together by illustrating some of the common elements and concerns they share. It is becoming evident that future dam safety activities for the hydroelectric, water supply and related dams will be carried out in a more privatized and globalized context by organizations less acquainted with traditional dam safety practices than in the past. If so, then tailings dam experience can be a pathfinder for how and why dam safety needs to be addressed in a corporate setting. It shows that the perceived effects of dam failures, environmental and otherwise, influence corporate damowners in ways that can amplify manyfold the objective consequences that dam safety assessments usually address. Dam safety professionals might do well to better understand and effectively communicate the financial and organizational impacts of dam failure on the corporate entity in ways that go beyond the traditional assessment of downstream hazard and failure consequences. Dam safety efforts can come to be seen less as imposed burdens of dam ownership and more as activities consistent with shareholder accountability and corporate self-interest. The Canadian mining industry, in adopting this perspective, is confirming that support for dam safety activities from the highest corporate level is essential for implementing them throughout the

  11. Dam safety operating guidelines

    International Nuclear Information System (INIS)

    Elsayed, E.; Leung, T.; Kirkham, A.; Lum, D.

    1990-01-01

    As part of Ontario Hydro's dam structure assessment program, the hydraulic design review of several river systems has revealed that many existing dam sites, under current operating procedures, would not have sufficient discharge capacity to pass the Inflow Design Flood (IDF) without compromising the integrity of the associated structures. Typical mitigative measures usually considered in dealing with these dam sites include structural alterations, emergency action plans and/or special operating procedures designed for extreme floods. A pilot study was carried out for the Madawaska River system in eastern Ontario, which has seven Ontario Hydro dam sites in series, to develop and evaluate the effectiveness of the Dam Safety Operating Guidelines (DSOG). The DSOG consist of two components: the flood routing schedules and the minimum discharge schedules, the former of which would apply in the case of severe spring flood conditions when the maximum observed snowpack water content and the forecast rainfall depth exceed threshold values. The flood routing schedules would identify to the operator the optimal timing and/or extent of utilizing the discharge facilities at each dam site to minimize the potential for dam failures cased by overtopping anywhere in the system. It was found that the DSOG reduced the number of structures overtopped during probable maximum flood from thirteen to four, while the number of structures that could fail would be reduced from seven to two. 8 refs., 4 figs., 3 tabs

  12. Effects of substituting groundnut cake with acacia seed kernel meal ...

    African Journals Online (AJOL)

    The study examined the effects of replacing groundnut cake (GNC) with Acacia nilotica seed kernel meal (ASKM) in the diets of broilers and the effects of such on ... Serum metabolites were not affected by the treatment except alkaline phosphatasc and billirubin that were significantly (P < 0.05) lowered by 20% inclusion of ...

  13. The response of Acacia karroo plants to defoliation by hand ...

    African Journals Online (AJOL)

    Shoot production of all plants defoliated by hand was no different to that of the undefoliated control plants and was considerably less than that of the plants defoliated by goats. Keywords: acacia karroo; browse production; browsing; clipping; defoliation; goats; growth stimulation; leaf growth; leaves; shoot growth; shoot ...

  14. Effects of feeding the seeds of Prosopis laevigata, Acacia schaffneri ...

    African Journals Online (AJOL)

    Effects of feeding the seeds of Prosopis laevigata, Acacia schaffneri and Ceratonia siliqua on the performance of broiler chicks. G Álvarez-Fuentes, JC García-López, JM Pinos-Rodríguez, JR Aguirre-Rivera, Y Jasso-Pineda, SG Celestino-Santillán ...

  15. Contribution of Acacia nilotica products to the rural livelihood of ...

    African Journals Online (AJOL)

    The study examined the contribution of Acacia nilotica products to the rural livelihood of people in Wamako community of Sokoto State. Structured and open ended questionnaires were distributed to respondent. Twelve (12) villages were purposively selected from eight (8) Districts. Simple random sampling was used to ...

  16. Antimicrobial activity of pentacyclic triterpenes isolated from Acacia ...

    African Journals Online (AJOL)

    Acacia mellifera has been used widely in traditional African medicines against various diseases. Among the Kipsigis community of Kenya, water extracts from the plant is used for the treatment of skin diseases, coughs and gastrointestinal ailments. The aim of the study was to provide scientific rationale for the use of the plant ...

  17. ( Acacia melanoxylon ) in Southern Cape Forests, South Africa

    African Journals Online (AJOL)

    Australian Blackwood (Acacia melanoxylon) was actively introduced into the indigenous forests of the southern Cape until about 1930. On the perception that this exotic species constituted a threat to the indigenous forest, a policy of eradication was followed. This perception that Blackwood is capable of progressively ...

  18. Lethality of the aqeous extracts of Acacia nilotica, Guiera ...

    African Journals Online (AJOL)

    Cytotoxic activity indicated by lethal effects (that is mortality rate) of aqueous extracts of fruits of Acacia nilotica, stem bark of Kigelia africana, roots of Securidaca longepedunculata, and leaves of Guiera senegalensis on the culex mosquito larva was investigated by direct contact method. Larvicidal effects were observed with ...

  19. Behavior of Acacia Plants Installed on Substrates Based on ...

    African Journals Online (AJOL)

    The present study aims principally the evaluation of germination and of plant growth of Acacia cyanophylla installed, on the one hand, on the gross forestry compost (CSB) in its purest form, produced in a forest nursery in Tunisia, on the other hand, on the CSB mixed with poultry methacompost (MCA) refined (solid residue ...

  20. Acacia mearnsii industry overview: Current status, key research and ...

    African Journals Online (AJOL)

    Acacia mearnsii bark tannins are used in the leather industry, adhesives for wood composites, water flocculants and specialty products for the chemical, food and beverage industries. The world demand for vegetable tannins has remained unchanged over the past two decades due to intense competition from synthetic ...

  1. Ecology and Conservation of Acacia senegal in the Rangelands ...

    African Journals Online (AJOL)

    Ecology and Conservation of Acacia senegal in the Rangelands ofLuwero and Nakasongola Districts. Jacob Godfrey Agea, Joseph Obua, Sara Namirembe, Mukadasi Buyinza, Daniel Waiswa. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  2. Agroforestry potential of Acacia senegal in the rangelands of luwero ...

    African Journals Online (AJOL)

    Agroforestry potential of Acacia senegal in the rangelands of luwero and Nakasongola districts. Jacob Godfrey Agea, Joseph Obua, Sara Namirembe, Mukadasi Buyinza, Daniel Waiswa. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  3. Analysis of dendrometric characteristics of Acacia senegal (L.) Willd ...

    African Journals Online (AJOL)

    The study gives an analysis of the dendrometric parameters of a middle Sahelian species (Acacia senegal) in semi-arid environment to get better knowledge of its behavior. The research lays the principle that the species behaves differently according to the ecogeographical stations. So, its characteristics change from one ...

  4. Increased gum arabic production after infestation of Acacia senegal ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the correlation between the beetle Agrilus nubeculosus and gum arabic production by Acacia senegal. Some trees were tapped and left open to facilitate infestation by A. nubeculosus and others were covered with wire mesh as control. Gum yield, physical and chemical properties of ...

  5. Evaluation Support and Follow Up (Acacia) | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The IDRC program initiative, Acacia (communities and the information society in Africa), seeks to integrate an evaluation process within its activities and those of its partners. This project aims to ... A new website and resource library will help improve developing country registration and information systems for vital events.

  6. Acacia Prospectus 2006-2011 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-13

    Dec 13, 2010 ... Meanwhile, the developed world has raced ahead to embrace new ICTs and ICT infrastructure, driving down costs and integrating ICTs as a basic infrastructure of modern economies. The failure of African countries to keep pace with this change has far-ranging implications and it is the mission of the Acacia ...

  7. Effects of substituting sunflower seed cake with Acacia tortilis pods ...

    African Journals Online (AJOL)

    A study was undertaken to avaluate the effects of substituting sunflower seed cake with Acacia tortilis pods as a protein source in supplementing Small East African goats fed a basal diet of Brachiaria brizantha hay. Twenty-four growing female goats with mean body weight of 9. 71 = 1.56 kg were used in a growth ...

  8. Antimicrobial activity analysis of extracts of Acacia modesta ...

    African Journals Online (AJOL)

    Antimicrobial activity of extracts of certain herbs including Acacia modesta (leaf and stem), Artimisia absinthium (leaf and stem), Nigella sativa (seeds) and i (root) was evaluated against three Gram positive and two Gram negative microorganisms. The Gram positive organisms included Bacillus subtalis (ATCC 6633), ...

  9. A comparison between Acacia and Combretum leaves utilized by ...

    African Journals Online (AJOL)

    Various studies on the food preferences of giraffe indicate that the leaves of the Acacia and Combretum species are the most important food items selected. The present study was aimed at comparingth e chemical compositiono f the leavesa nd explainingt he utilizationo f both these plant groups by giraffe. The protein ...

  10. Nitrogen fixation of Acacia mangium Willd. from two seed sources ...

    African Journals Online (AJOL)

    Phosphorus (P) is required to facilitate the fixation of atmospheric nitrogen (N) by leguminous species such as Acacia mangium. We studied the N fixation of A. mangium trees grown from two seed sources. These consisted of bulk seedlots collected from seed orchards in Sumatra, one based on natural provenances from ...

  11. Fitness and its variation among populations of Acacia tortilis subsp ...

    African Journals Online (AJOL)

    Administrator

    2008-07-23

    Jul 23, 2008 ... Acacia tortilis subsp. raddiana (Fabaceae) plays an important role in the life of desert animals and is a major source of livestock feed ... raddiana grows in desert wadis and sandy plains, usually in water catchments areas in ...... Randomization and Monte Carlo Methods in Biology. Chapman & Hall, London.

  12. The effect of Acacia karroo supplementation and thermal ...

    African Journals Online (AJOL)

    The objective of the current study was to determine the effect of Acacia karroo supplementation and thermal preparation on consumer sensory scores of meat from indigenous Xhosa lop-eared goat breed. 18 castrated four-month-old Xhosa lop-eared kids were kept at the University of Fort Hare Farm until slaughter. Sample ...

  13. Soil nutrient ecology associated with Acacia sieberana at different ...

    African Journals Online (AJOL)

    Reports on a study conducted on three aspects of soil nutrient ecology in an Acacia sieberana savanna. Information was collected about the effects of a savanna tree species on soil fertility, and the influence of savanna trees on mycorrhizal abundance was investigated. Mycorrhizal dependence of the indigenous African ...

  14. Characterization of tannin-based adhesives from Acacia mangium barks

    International Nuclear Information System (INIS)

    Siti Fatahiyah Mohamada; Pizzi, Antonio

    2010-01-01

    The aim of this work is to demonstrate the performances of Acacia Mangium tannin-based tannin designed as adhesive in the particleboard production. The tannin was extracted from acacia mangium barks in differences medium extraction. Three difference medium, (1)Water (Control), (2)Na 2 SO 3 (4 %) / Na 2 CO 3 (0.4 %) and (3) Na 2 SO 3 (8 %) / Na 2 CO 3 (0.8 %) used, the (3) medium extraction produce then highest yield (25.8 %) follow the (2) medium extraction (21.6%) and the less yield (17.7%). To evaluate the mechanical performances of optimal Acacia mangium tannin-based adhesives, particleboard were produced using 3 differences hardener and mechanical properties (Internal bonding) were investigated. The performance of these panels is comparable to those of particle panels commercial. The results showed that particleboard panels bonded with parafomaldehid (0.392 Mpa) exhibited better mechanical properties, continue particleboard panel hardened with hexamine (0.367 MPa) and particleboard panel bonded with glyoxol-tannin based adhesives (0.244 MPa). This show the suitable harder for acacia mangium tannin are formaldehyde > hexamine > glyoxol. (author)

  15. Antipyretic and analgesic activities of aqueous extract of Acacia ...

    African Journals Online (AJOL)

    This study was designed to investigate the scientific basis for the use of Acacia nilotica root extract for treatment of fever and pain in traditional medical practice. Anti-Pyretic study was carried out using Brewerʼs yeast suspension to induce pyrexia. The hot plate, tail immersion and acetic acid-induced writhing tests were the ...

  16. Inducible defences in Acacia sieberiana in response to giraffe ...

    African Journals Online (AJOL)

    In an observational study, we investigated the physical and chemical defenses in Acacia sieberiana var. woodii in response to different intensities of giraffe herbivory. Trees with high browsing intensity had significantly longer spines, smaller leaves and higher total cyanide (prussic acid) concentrations than trees with low ...

  17. Improving salinity tolerance of Acacia saligna (Labill.) plant by ...

    African Journals Online (AJOL)

    This study was carried out to investigate the alleviation of salt stress (0, 6.25, 12.50 and 25 dS/m) on growth and development of Acacia saligna, grown in sandy loam sterile soil by using arbuscular mycorrhizal fungi (AMF) and Sinorhizobium terangae (R), individually or in combination (AMF+R). Growth and nodulation ...

  18. Allegheny County Dam Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the point locations of dams in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  19. The roles of soil macrofauna on litter decomposition of Acacia mangium Willd

    Directory of Open Access Journals (Sweden)

    MUSYAFA

    2005-01-01

    Full Text Available Acacia mangium has been widely planted in industrial forest plantation (HTI. High litter accumulation in floor of A. mangium (Acacia plantation due to slow process of decomposition, may disturb nutrient cycling process. It is also vulnerable to forest fire especially in dry season. The research was aimed to clarify the density of soil macrofauna in Acacia plantation and the roles of macrofauna in the decomposition of Acacia litter. The density of macrofauna was estimated by using pitfall traps and hand-sorting method in Acacia stand, at Wanagama Reaserch Center, Gadjah Mada University (GMU. In the laboratory, Spirobolus sp. (Diplopoda were fed with the litter of Acacia and the ingestion rate, defecation rate, and assimilatioan rate were determined. C and N content of the litter and feces were analyzed at Laboratory of Soil Science, Faculty of Agriculture GMU. The results showed that the density of soil macrofauna was low (74.6 individual/m2. The study in laboratory showed that Spirobolus did not est newly fallen leaves of Acacia. Ingestion rate, defecation rate, assimilation efficiency of millipede fed with partly decomposed Acacia leaves were 76.8 mg/g/day, 7.0 mg/g/day, 6.1 mg/g/day respectively. C/N ratio of feces was lower than that of partly decomposed Acacia leaves. It indicated significant change during gut passage of Spirobolus sp. This millipede should be introduced in Acacia plantation as a potential decomposer.

  20. Utilization of By-products of Acacia processing for Biogas Production

    OpenAIRE

    Lehkonen, Katja

    2016-01-01

    Acacia is a widely used raw material in South America, South Africa and Australia. Acacia is processed for different purposes e.g.in manufacturing barbeque char and tannin extracts which are further refined as biopolymers. By-products generated in processing are poorly utilized. Processing residues are mostly landfilled instead of considering them as a value added raw material. Thus, utilization of these by-products is an important new research subject due to increasing use of acacia tree wor...

  1. Karakter Morfologi Hibrid Acacia (a. Mangium X a. Auriculiformis) Di Persemaian

    OpenAIRE

    Sunarti, Sri

    2014-01-01

    The superiority of Acacia hybrid (A. mangium x A. auriculiformis) compared to the parent trees as fast growth, straight bole, ligth branching, more tolerance to pest and desease and had better wood properties. In order to maintain the superiority, it should be propagated vegetatively. However, the propagation potential of Acacia spp usually decreased by increasing the age of plant (aging effect). To prevent the aging effect on Acacia hybrid, vegetative propagation of selected trees should ...

  2. Dam safety guidelines

    International Nuclear Information System (INIS)

    Anderson, I.; Raska, C.

    1999-01-01

    The objectives of this report are (1) to define the requirements and outline the guidelines so that the safety of existing dams can be investigated and identified in a consistent and adequate manner across Canada, (2) to enable the consistent evaluation of dam safety deficiencies leading to the construction of improvements which contribute to dam safety, and (3) to provide a basis for dam safety legislation and regulation. The document contains statements of safety requirements, explanatory guidelines and commentaries. These clarify and expand upon some of the requirements and guidelines, and discuss alternative approaches to meeting the safety requirements. The report is divided into 12 sections which address criteria for earthquakes, floods and emergency preparedness. Geotechnical considerations and the effects of the reservoir environment are also discussed. These guidelines are not intended as design specifications for dam safety evaluation, design, construction or rehabilitation. From time to time, portions of these guidelines will be updated and issued to CDSA members. The user is responsible for ensuring that the most up-to-date version is being used. refs, tabs

  3. Dams and Intergovernmental Transfers

    Science.gov (United States)

    Bao, X.

    2012-12-01

    Gainers and Losers are always associated with large scale hydrological infrastructure construction, such as dams, canals and water treatment facilities. Since most of these projects are public services and public goods, Some of these uneven impacts cannot fully be solved by markets. This paper tried to explore whether the governments are paying any effort to balance the uneven distributional impacts caused by dam construction or not. It showed that dam construction brought an average 2% decrease in per capita tax revenue in the upstream counties, a 30% increase in the dam-location counties and an insignificant increase in downstream counties. Similar distributional impacts were observed for other outcome variables. like rural income and agricultural crop yields, though the impacts differ across different crops. The paper also found some balancing efforts from inter-governmental transfers to reduce the unevenly distributed impacts caused by dam construction. However, overall the inter-governmental fiscal transfer efforts were not large enough to fully correct those uneven distributions, reflected from a 2% decrease of per capita GDP in upstream counties and increase of per capita GDP in local and downstream counties. This paper may shed some lights on the governmental considerations in the decision making process for large hydrological infrastructures.

  4. Methods for Extraction and Charaterization of Tannins from Some Acacia Species of Sudan

    Directory of Open Access Journals (Sweden)

    Isam Eldin Hussein Elgailani

    2016-06-01

    Full Text Available The study is aimed to analyze and compare extraction methods of tannins from three common Acacia species of Sudan. The Acacia species selected were Acacia nilotica, Acacia seyal and Acacia senegal. Bark samples from bulk collections of the three Acacia species were extracted with water, 80% methanol and 70% acetone. Two sets of extraction were made, one by boiling and a second by shaking the samples in the respective solvents for eight hours at room temperature. Although the amount of material extracted by these two procedures did not differ greatly (P > 0.05, 70% acetone was a more efficient solvent than either water or 80% methanol. The tannins of mature fruits extract of Acacia nilotica were identified by using Thin Layer Chromatography (TLC, Ultraviolet and Infrared spectroscopy. Comparisons of absorption spectra and TLC of the reference tannins and some phenolics with that of Acacia nilotica extracts revealed the presence of both condensed and hydrolyzable tannins, since it consists of catechin, tannic and gallic acids. Catechin considered to be the phenolic precursor of condensed tannins. Hydrolysis of Acacia nilotica extract, tannic and gallic acids by butanolic-hydrochloric acid yielded gallic acid which is considered to be a chemical precursor of hydrolyzable tannins

  5. Methods for extraction and characterization of tannins from some acacia species of sudan

    International Nuclear Information System (INIS)

    Elgailani, I.E.H.; Ishak, C.Y.

    2016-01-01

    The study is aimed to analyze and compare extraction methods of tannins from three common Acacia species of Sudan. The Acacia species selected were Acacia nilotica, Acacia seyal and Acacia senegal. Bark samples from bulk collections of the three Acacia species were extracted with water, 80% methanol and 70% acetone. Two sets of extraction were made, one by boiling and a second by shaking the samples in the respective solvents for eight hours at room temperature. Although the amount of material extracted by these two procedures did not differ greatly (P > 0.05), 70% acetone was a more efficient solvent than either water or 80% methanol. The tannins of mature fruits extract of Acacia nilotica were identified by using Thin Layer Chromatography (TLC), Ultraviolet and Infrared spectroscopy. Comparisons of absorption spectra and TLC of the reference tannins and some phenolics with that of Acacia nilotica extracts revealed the presence of both condensed and hydrolyzable tannins, since it consists of catechin, tannic and gallic acids. Catechin considered to be the phenolic precursor of condensed tannins. Hydrolysis of Acacia nilotica extract, tannic and gallic acids by butanolic-hydrochloric acid yielded gallic acid which is considered to be a chemical precursor of hydrolyzable tannins. (author)

  6. (Anthene amarah Guerin) selects unseasonal young Acacia shoots ...

    African Journals Online (AJOL)

    1989-06-29

    Jun 29, 1989 ... Sth. Afr. 1: 29-32. BHADORIA, B.K. & GUPTA, R.K. 1981. A note on hydrocyanic acid content of Acacia leucophloea Roxb. 85. WilJd. Cu"ent Science 50: 689-690. CLARK, C.G. & DICKSON, C.G.c. 1971. Life histories of. South African Iycaenid butterflies. Purnell, Cape Town. DUNHAM, K.M. 1980. The diet of ...

  7. Acacia: An exclusive survey on in vitro propagation

    Directory of Open Access Journals (Sweden)

    Saikat Gantait

    2018-04-01

    Full Text Available The current survey exemplifies the achievements on experimental results of production of planting materials through in vitro direct or indirect organogenesis of genus Acacia. Several species of Acacia have been given due importance in tree tissue culture owing to their proven wasteland reclamation ability, ecological and economical significance. Plant cell, tissue and organ culture-based techniques have been employed in forest tree research for successful reforestation and forest management programs. The relevance of tissue culture methods has gained impetus to meet the growing demands for biomass and forest products. Ever since the last four decades, in vitro protocols are being developed with the aim to regenerate several woody species. This survey strives to serve as a compendium of various routine processes involving organogenesis of Acacia via in vitro; which would encouragingly be worthwhile for researchers to exploit this perennial woody legume with enormous multidimensional value, via more innovative approaches, in order to promote the cause for its improvement. Keywords: Callogenesis, Explant, Organogenesis, Plant growth regulators, Somatic embryogenesis, Woody plant

  8. Antioxidant and sensorial properties of acacia honey supplemented with prunes

    Directory of Open Access Journals (Sweden)

    Tumbas Vesna T.

    2012-01-01

    Full Text Available The changes in total phenol and flavonoid content, as well as antioxidant activity was monitored in acacia honey supplemented with prunes in 20, 30 and 40% mass concentrations. The total phenolic content increased by 2.5 times (from 16.18 to 41.64 mg GAE/100 g with increasing concentration of prunes in honey, while the increase in flavonoid content was even higher, approximately 11.5-fold (from 2.65 to 30.86 mg RE/100 g. The addition of prunes also improved the antioxidant activity of acacia honey. The honey samples with highest content of prunes, 40%, exhibited the best antioxidant activity measured by hydroxyl radical sacvenging assay (EC50 •OH=4.56 mg/ml, 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical scavenging assay (EC50 DPPH=16.48 mg/ml, and reducing power (EC50 RP=81.17 mg/ml. Judging from the high correlation coefficients, ranging from 0.771 to 0.947 for total phenolics, and from 0.862 to 0.993 for total flavonoids, it is obvious that these compounds were associated with the antioxidant mechanisms. On the other hand, sensorial properties of supplemented honeys were lower than that of pure acacia honey, where flavor of supplemented honey was the least affected. Our results indicate that the supplementation of honey with prunes improves antioxidant activity of honey by enriching the phenolic composition, with slight modifications in sensorial characteristics.

  9. Small dams need better management

    Science.gov (United States)

    Balcerak, Ernie

    2012-03-01

    Many small dams around the world are poorly maintained and represent a safety hazard, according to Pisaniello et al. Better oversight of small dams is needed, the authors argue. The researchers reviewed literature, conducted case studies in four states in Australia, and developed policy benchmarks and best practices for small-dam management. Small dams, often just several meters high and typically privately owned by individual farmers, have historically caused major damage when they fail. For instance, in China in 1975, 230,000 people died when two large dams failed because of the cumulative failure of 60 smaller upstream dams. In the United States, in 1977 the 8-meter-high Kelly Barnes Lake dam failed, killing 39 people. Many other small-dam failures around the world have resulted in casualties and severe ecological and economic damage.

  10. ANATOMIA DA MADEIRA DE Acacia nitidifolia Speg. (Leguminosae Mimosoideae. Wood anatomy of Acacia mitidifolia Spreg. (Leguminosae Mimosoideae.

    Directory of Open Access Journals (Sweden)

    José Newton Cardoso Marchiori

    1991-12-01

    Full Text Available O presente trabalho visa o estudo anatômico da madeira de Acacia nitidifolia Speg. A estrutura anatômica apresenta porosidade difusa, elementos vasculares curtos, placas de perfurações simples, pontuações intervasculares ornamentadas e em arranjo alterno, parênquima axial paratraqueal vasicêntrico e marginal cristalífero, raios homogêneos comumente 2-3 seriados e fibras libriformes septadas. A presença de canais intercelulares axiais e de canais celulares na estrutura radial, tem grande importância taxonômica. Este último caráter era desconhecido para o gênero Acacia. A estrutura anatômica da madeira indica que a espécie em estudo pode ser classificada na série Vulgares Benth., que corresponde, em linhas gerais, ao sub-gênero Aculeiferum Vassal.

  11. Dam health diagnosis and evaluation

    Science.gov (United States)

    Wu, Zhongru; Su, Huaizhi

    2005-06-01

    Based on the bionics principle in the life sciences field, we regard a dam as a vital and intelligent system. A bionics model is constructed to observe, diagnose and evaluate dam health. The model is composed of a sensing system (nerve), central processing unit (cerebrum) and decision-making implement (organism). In addition, the model, index system and engineering method on dam health assessment are presented. The proposed theories and methods are applied to evaluate dynamically the health of one concrete dam.

  12. DECOMPOSIÇÃO DAS PODAS DAS LEGUMINOSAS ARBÓREAS Gliricidia sepium E Acacia angustissima EM UM SISTEMA AGROFLORESTAL

    Directory of Open Access Journals (Sweden)

    Patrícia Diniz de Paula

    2015-01-01

    Full Text Available ABSTRACT The Agroforestry Systems (SAFs bring multiple benefits and they are an alternative to minimize environmental degradation, and to achieve a sustainable development, due to greatest diversity of species. This study evaluated the contribution of the leguminous trees, gliricídia sepium and Acacia angustissima , grown in alley cropping of banana ( Musa sp. and “açaí” palm ( Euterpe oleraceae used as green manure in the implantation of an Agroforestry Systems. They were compared the production of biomass, nutrients cycling, nitrogen intake, activity and diversity of soil fauna, and banana productivity in the SAF, and with the usage of the legume Pueraria phaseoloides and nitrogen fertilization. The SAF implantation occurred in May 2004, at the Research Center of Embrapa Agrobiologia, in Seropédica, Rio de Janeiro State. The following year it was planted the forest African mahogany specie ( Kaya senegalensis , at the centre of the legumes alleys. The experimental design was of randomized blocks with five treatments and four repetitions. The treatments consisted of the leguminous trees arranged between the lines of bananas and the “açaí” palm, and they were: acacia angustíssima ( Acacia angustissima , tropical kudzu ( Pueraria phaseoloides , and gliricídia (G liricídia sepium ; besides application of nitrogen as urea and spontaneous vegetation. To quantify the production of biomass, and the release of N, P, Ca, Mg and K, the legumes branches were cut and the kudzu tropical and spontaneous vegetation were mowed, in the rainy and dry seasons. The determination of remaining dry matter, releasing of nutrients, decomposition rates, and half life time of plant residues were held to 50 grams of fresh material from litterbags, placed on the soil surface, sampled at 0, 5, 10, 15, 20, 25, 30, 40, 60 and 75 days after the installation of the experiment. Acacia angustissima and kudzu tropical showed higher dry biomass, 9.5 and 10.8 Mg ha

  13. Proceedings of dam safety seminar

    International Nuclear Information System (INIS)

    1989-01-01

    A seminar was held to discuss issues of dam safety. Presentations concerned dam safety evaluation, dam monitoring, erosion protection, ice loads, spillway design, flood prediction, emergency preparedness, reservoir management, rehabilitation, and foundation design. Separate abstracts have been prepared for 16 papers from the seminar

  14. A review of the Pseudomyrmex ferrugineus and Pseudomyrmex goeldii species groups: acacia-ants and relatives (Hymenoptera: Formicidae).

    Science.gov (United States)

    Ward, Philip S

    2017-02-06

    The Pseudomyrmex ferrugineus group contains the Mesoamerican acacia-ants, an assemblage of species that inhabit and protect swollen-thorn acacias (Vachellia spp.). Recent phylogenetic studies have confirmed the existence of two generalist (dead twig-inhabiting) species that are embedded within the P. ferrugineus group. They are described here as P. evitus sp. nov. (occurring from Mexico to Costa Rica) and P. feralis sp. nov. (Guatemala). The morphological definition of the P. ferrugineus group is revised to incorporate additional variability in the worker and queen castes. The previous diagnosis of the males, based largely on features of the genitalia, requires little revision. Closely related to the P. ferrugineus group is a clade of five predominantly South American species, here designated and diagnosed as the P. goeldii group. The five species, P. goeldii (Forel), P. laevifrons Ward, P. micans sp. nov., P. obtusus sp. nov., and P. parvulus sp. nov., are characterized and illustrated. P. laevifrons and P. micans are closely related and difficult to distinguish, possibly reflecting incomplete isolation. Keys are provided for the identification of the species in both groups.

  15. Limnology of hartbeespoort dam

    CSIR Research Space (South Africa)

    Ashton, PJ

    1985-01-01

    Full Text Available Hartbeespoort Dam is a hypertrophic, warm, monomictic impoundment. With a mean depth of 9.6 m and a surface area of 20 km2, the system demonstrates that hypertrophy is not confined to small shallow lakes as concluded by Barica (1981...

  16. Effect of elephant browsing on selected species of Acacia along the ...

    African Journals Online (AJOL)

    Elephant damage was assessed in 1,007 Acacia trees and responses between Acacia tortilis and A. kirkii in Ruaha National park were compared in 30 transects randomly placed in 38.8 km2 on the northern bank of Great Ruaha River (GRR) basing on six browsing categories and four debarking classes. There was no ...

  17. The birds of the alien Acacia thickets of the South-western Cape

    African Journals Online (AJOL)

    THE BIRDS OF THE ALIEN ACACIA THICKETS. OF THE SOUTH WESTERN CAPE. 1. M. WINTERBOTTOM. Percy FitzPatrick Institute of African Ornithology, University of Cape Town. About 1876, the Cape Superintendent of Plantations began using the Australian Acacia cyanophylla and A. cyclops on a large scale to fix ...

  18. Intra-species variation of the properties of gum exudates from Acacia ...

    African Journals Online (AJOL)

    Gum exudates from Acacia senegal var. senegal and Acacia seyal var. fistula from Tanzania have been analyzed and their inter- and intra-species variation of their properties evaluated. The results show that significant inter-species variation of the properties of the gum exudates from the two species exist, whereas only ...

  19. Growth patterns and annual growth cycle of Acacia karroo Hayne in ...

    African Journals Online (AJOL)

    The use and replenishment of carbohydrate reserves in Acacia karroo is closely related to the successive events of the annual growth cycle. Acacia karroo displayed the rapid and substantial decline in non-structural carbohydrates typical of deciduous woody species. In addition, each time shoot, leaf or reproductive organs ...

  20. The birds of the alien Acacia thickets of the South-western Cape

    African Journals Online (AJOL)

    It is of some interest to compare the avifauna of these Acacia thickets with that of stands of mixed exotic trees, often including some Acacia but also Eucalyptus, Pinus, Quercus,. Populus and other genera. Only 50 lists are available for this habitat, however. There are. 35 species which occur in 5% or more of the lists;of which ...

  1. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Science.gov (United States)

    2010-04-01

    ... denture adhesive. 872.3400 Section 872.3400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... and sodium borate with or without acacia denture adhesive. (a) Identification. A karaya and sodium borate with or without acacia denture adhesive is a device composed of karaya and sodium borate with or...

  2. Water Control Manual: Sepulveda Dam and Reservoir, Los Angeles River, California.

    Science.gov (United States)

    1989-05-01

    Generally the quality of urban base flow has been so poor that these facilities are 4-7 rarely used. A downstream reach with cobblestone invert near...by the Los Angeles County Drainage Area Review (see table 1-01; Draft: Los Angeles County Drainage Area Review: Part I, Hydrology Report). b. Rubber ...Dam. The City of Los Angeles Department of Water and Power construct a rubber dam approximately 10 miles below Sepulveda Dam for diversion of water into

  3. Ecology of the plant-dwelling spiders (Arachnida: Araneae of the Erfenis Dam Nature Reserve, South Africa

    Directory of Open Access Journals (Sweden)

    René Fourie

    2013-04-01

    Full Text Available As part of the South African National Survey of Arachnida in the Grassland Biome, foliage-dwelling and grass-dwelling spiders (Arachnida: Araneae were collected in the Erfenis Dam Nature Reserve in the central Free State Province from November 2005 to August 2007. Foliage-dwelling spiders were collected from three common tree or shrub species (Acacia karroo, Searsia ciliata and Searsia lancea and grass-dwellers from four contrasting grasslands (uniform Themeda triandra, mixed, weedy and woodland grasslands. From the grass layer, 1649 spiders were collected, representing 15 families and 82 species, whilst 496 tree-dwelling spiders were collected that represented 17 families and 52 species. There was some overlap in the fauna of the two strata, resulting in a total of 108 species from 18 families being collected. The Araneidae, Philodromidae, Salticidae and Thomisidae were consistently the most abundant in all grassland types and tree species, although Salticidae were scarce on A. karroo. Assemblage analysis indicates high similarity and overlap in the fauna of the four grassland types, suggesting that the structural complexity of grasslands has a limited effect on species composition. In contrast, the foliage-dwelling assemblages were more distinct, with only some overlap between the faunas of S. ciliata and A. karroo, suggesting a stronger vegetation structural effect in shaping arboreal spider assemblages. The isolation of trees and shrubs within the extensive grassy habitat may contribute to the more unique fauna and lower species richness of the woody vegetation. Conservation implications: This study uncovered a rich diversity of plant-dwelling spiders from central South Africa. Grassland faunas show considerable temporal variation and some variability in microhabitat preferences, and sampling protocols should take this into account when spiders are considered in management plans and biodiversity surveys in reserves and private land.

  4. Ecology of the plant-dwelling spiders (Arachnida: Araneae of the Erfenis Dam Nature Reserve, South Africa

    Directory of Open Access Journals (Sweden)

    René Fourie

    2013-02-01

    Full Text Available As part of the South African National Survey of Arachnida in the Grassland Biome, foliage-dwelling and grass-dwelling spiders (Arachnida: Araneae were collected in the Erfenis Dam Nature Reserve in the central Free State Province from November 2005 to August 2007. Foliage-dwelling spiders were collected from three common tree or shrub species (Acacia karroo, Searsia ciliata and Searsia lancea and grass-dwellers from four contrasting grasslands (uniform Themeda triandra, mixed, weedy and woodland grasslands. From the grass layer, 1649 spiders were collected, representing 15 families and 82 species, whilst 496 tree-dwelling spiders were collected that represented 17 families and 52 species. There was some overlap in the fauna of the two strata, resulting in a total of 108 species from 18 families being collected. The Araneidae, Philodromidae, Salticidae and Thomisidae were consistently the most abundant in all grassland types and tree species, although Salticidae were scarce on A. karroo. Assemblage analysis indicates high similarity and overlap in the fauna of the four grassland types, suggesting that the structural complexity of grasslands has a limited effect on species composition. In contrast, the foliage-dwelling assemblages were more distinct, with only some overlap between the faunas of S. ciliata and A. karroo, suggesting a stronger vegetation structural effect in shaping arboreal spider assemblages. The isolation of trees and shrubs within the extensive grassy habitat may contribute to the more unique fauna and lower species richness of the woody vegetation. Conservation implications: This study uncovered a rich diversity of plant-dwelling spiders from central South Africa. Grassland faunas show considerable temporal variation and some variability in microhabitat preferences, and sampling protocols should take this into account when spiders are considered in management plans and biodiversity surveys in reserves and private land.

  5. Effect of Rhizobium and Mycorhiza inoculation on the nursery growth of Acacia and Teline monspessulana

    International Nuclear Information System (INIS)

    Layton, G; Lozano de Yunda, A; Chaparro, H

    1999-01-01

    In an experiment accomplished in the tree nursery Tisquesusa located in Madrid (Cundinamarca) was evaluated the effect of the inoculation with strains selected of foreign and Indigenous rhizobium and Arbuscular mycorrhizal fungi am (Glomus folescutolum) on the growth, nitrogen fixation, and micorrization of Acacia (Acacia decurrens) and Retamo (Teline monspessulana) that they are used In soils recovery by the Corporacion Autonoma Regional de Cundinamarca CAR. The studied species presented positive response to the inoculation with rhizobium; the indigenous strain DQ6-09, isolated in Guatavita (Cundinamarca), presented the better results in Retamo and also in Acacia alone and in mixture with the foreign strain T1881. The inoculation with fungi AM increased the heights, dry weights, phosphorus content and percentage of micorrization in Acacia and Retamo. The double inoculation with fungi ma and rhizobium it did not increase the nitrogen fixing of Acacia while in Retamo was presented a positive effect with the strain DQ6-09

  6. Expansion at Olympic Dam

    International Nuclear Information System (INIS)

    Lewis, C.

    1997-01-01

    The Olympic Dam orebody is the 6th largest copper and the single largest uranium orebody in the world. Mine production commenced in June 1988, at an annual production rate of around 45,000 tonnes of copper and 1,000 tonnes of uranium. Western Mining Corporation announced in 1996 a proposed $1.25 billion expansion of the Olympic Dam operation to raise the annual production capacity of the mine to 200,000 tonnes of copper, approximately 3,700 tonnes of uranium, 75,000 ounces of gold and 950,000 ounces of silver by 2001. Further optimisation work has identified a faster track expansion route, with an increase in the capital cost to $1.487 billion but improved investment outcome, a new target completion date of end 1999, and a new uranium output of 4,600 tonnes per annum from that date

  7. Dam spills and fishes

    International Nuclear Information System (INIS)

    1996-01-01

    This short paper reports the main topics discussed during the two days of the annual colloquium of the Hydro-ecology Committee of EdF. The first day was devoted to the presentation of the joint works carried out by EdF, the Paul-Sabatier University (Toulouse), the Provence St-Charles University (Marseille), the ENSAT (Toulouse) and the CEMAGREF (Lyon and Aix-en-Provence) about the environmental impact of dam spills on the aquatic flora and fauna downstream. A synthesis and recommendations were presented for the selection and characterization of future sites. The second day was devoted to the hydro-ecology study of the dam reservoir of Petit-Saut (French Guyana): water reoxygenation, quality evolution, organic matter, plankton, invertebrates and fishes. The 134 French dams concerned by water spills have been classified according to the frequency of spills, the variations of flow rates created, and their impacts on fishing, walking, irrigation, industry, drinking water, navigation, bathing. Particular studies on different sites have demonstrated the complexity of the phenomena involved concerning the impact on the ecosystems and the water quality. (J.S.)

  8. 18 CFR 292.208 - Special requirements for hydroelectric small power production facilities located at a new dam or...

    Science.gov (United States)

    2010-04-01

    ... for hydroelectric small power production facilities located at a new dam or diversion. 292.208 Section... requirements for hydroelectric small power production facilities located at a new dam or diversion. (a) A hydroelectric small power production facility that impounds or diverts the water of a natural watercourse by...

  9. South Channel Dam Rehabilitation Project - Successfully Addressing Dam Rehabilitation Challenges

    OpenAIRE

    Graeser, M. D.; Jensen, M. C.

    2016-01-01

    The Post Falls South Channel Dam is located on the Spokane River in Post Falls, Idaho. The concrete gravity dam was constructed in 1906 and was recently rehabilitated. The rehabilitation project included several design elements; the primary objectives were the replacement of the six spillway gates and hoists and significant rehabilitation of the concrete. The South Channel Dam rehabilitation encountered several challenges due to the age and condition of the existing structure, the large scale...

  10. 1000 dams down and counting

    Science.gov (United States)

    O'Connor, James E.; Duda, Jeff J.; Grant, Gordon E.

    2015-01-01

    Forty years ago, the demolition of large dams was mostly fiction, notably plotted in Edward Abbey's novel The Monkey Wrench Gang. Its 1975 publication roughly coincided with the end of large-dam construction in the United States. Since then, dams have been taken down in increasing numbers as they have filled with sediment, become unsafe or inefficient, or otherwise outlived their usefulness (1) (see the figure, panel A). Last year's removals of the 64-m-high Glines Canyon Dam and the 32-m-high Elwha Dam in northwestern Washington State were among the largest yet, releasing over 10 million cubic meters of stored sediment. Published studies conducted in conjunction with about 100 U.S. dam removals and at least 26 removals outside the United States are now providing detailed insights into how rivers respond (2, 3).

  11. Mangrove endophyte promotes reforestation tree (Acacia polyphylla growth

    Directory of Open Access Journals (Sweden)

    Renata Assis Castro

    Full Text Available ABSTRACT Mangroves are ecosystems located in the transition zone between land and sea that serve as a potential source of biotechnological resources. Brazil's extensive coast contains one of the largest mangrove forests in the world (encompassing an area of 25,000 km2 along all the coast. Endophytic bacteria were isolated from the following three plant species: Rhizophora mangle, Laguncularia racemosa and Avicennia nitida. A large number of these isolates, 115 in total, were evaluated for their ability to fix nitrogen and solubilize phosphorous. Bacteria that tested positive for both of these tests were examined further to determine their level of indole acetic acid production. Two strains with high indole acetic acid production were selected for use as inoculants for reforestation trees, and then the growth of the plants was evaluated under field conditions. The bacterium Pseudomonas fluorescens (strain MCR1.10 had a low phosphorus solubilization index, while this index was higher in the other strain used, Enterobacter sp. (strain MCR1.48. We used the reforestation tree Acacia polyphylla. The results indicate that inoculation with the MCR1.48 endophyte increases Acacia polyphylla shoot dry mass, demonstrating that this strain effectively promotes the plant's growth and fitness, which can be used in the seedling production of this tree. Therefore, we successfully screened the biotechnological potential of endophyte isolates from mangrove, with a focus on plant growth promotion, and selected a strain able to provide limited nutrients and hormones for in plant growth.

  12. Colloids removal from water resources using natural coagulant: Acacia auriculiformis

    Science.gov (United States)

    Abdullah, M.; Roslan, A.; Kamarulzaman, M. F. H.; Erat, M. M.

    2017-09-01

    All waters, especially surface waters contain dissolved, suspended particles and/or inorganic matter, as well as several biological organisms, such as bacteria, algae or viruses. This material must be removed because it can affect the water quality that can cause turbidity and colour. The objective of this study is to develop water treatment process from Seri Alam (Johor, Malaysia) lake water resources by using natural coagulant Acacia auriculiformis pods through a jar test experiment. Jar test is designed to show the effectiveness of the water treatment. This process is a laboratory procedure that will simulate coagulation/flocculation with several parameters selected namely contact time, coagulant dosage and agitation speed. The most optimum percentage of colloids removal for each parameter is determined at 0.2 g, 90 min and 80 rpm. FESEM (Field-emission Scanning Electron Microscope) observed the small structures of final floc particles for optimum parameter in this study to show that the colloids coagulated the coagulant. All result showed that the Acacia auriculiformis pods can be a very efficient coagulant in removing colloids from water.

  13. Tannic extract potential as natural wood preservative of Acacia mearnsii

    Directory of Open Access Journals (Sweden)

    AMANDA G. DA SILVEIRA

    2017-12-01

    Full Text Available ABSTRACT High toxicity of the preservatives most frequently used in wood treatment and the resulting risks of handling pose a threat to small producers and to the environment. In an attempt to mitigate these problems, the present study was conducted with the objective of evaluating the preservative effect of tannic extract on biodeterioration of Acacia mearnsii wood. For this purpose, untreated and preserved specimens, some with tannin extract and some with a preservative mixture based on CCB (Chromated Copper Borate, were submitted to accelerated rotting trials with the fungus that causes white rot (Pycnoporus sanguineus for 16 weeks. The evaluations were made with a basis on weight loss and chemical components analysis, and they showed that the natural resistance of Acacia wood is moderate when exposed to the white rot fungus. The tannin concentrations showed similar effects to those of the CBB mixture in all evaluations, i.e., they significantly increased the biological resistance of the material, which started to be classified as very resistant to the fungus. Overall, the results suggest that tannin can be considered as a potential natural preservative product.

  14. Evaluation of Cytotoxicity and Genotoxicity of Acacia aroma Leaf Extracts

    Directory of Open Access Journals (Sweden)

    C. M. Mattana

    2014-01-01

    Full Text Available Acacia aroma, native plant from San Luis, Argentina, is commonly used as antiseptic and for healing of wounds. The present study was conducted to investigate the in vitro cytotoxicity and genotoxicity of hot aqueous extract (HAE and ethanolic extract (EE of A. aroma. The cytotoxic activity was assayed by neutral red uptake assay on Vero cell. Cell treatment with a range from 100 to 5000 μg/mL of HAE and EE showed that 500 μg/mL and 100 μg/mL were the maximum noncytotoxic concentrations, respectively. The CC50 was 658 μg/mL for EE and 1020 μg/mL for HAE. The genotoxicity was tested by the single-cell gel electrophoresis comet assay. The results obtained in the evaluation of DNA cellular damage exposed to varied concentrations of the HAE showed no significant genotoxic effect at range of 1–20 mg/mL. The EE at 20 mg/mL showed moderate genotoxic effect related to the increase of the DNA percentage contained in tail of the comet; DNA was classified in category 2. At concentrations below 5 mg/mL, the results of cytotoxicity and genotoxicity of aqueous and ethanolic extracts of Acacia aroma guarantee the safety at cell and genomic level. However further studies are needed for longer periods including animal models to confirm the findings.

  15. The Inhibition of Lipase and Glucosidase Activities by Acacia Polyphenol

    Directory of Open Access Journals (Sweden)

    Nobutomo Ikarashi

    2011-01-01

    Full Text Available Acacia polyphenol (AP extracted from the bark of the black wattle tree (Acacia mearnsii is rich in unique catechin-like flavan-3-ols, such as robinetinidol and fisetinidol. In an in vitro study, we measured the inhibitory activity of AP on lipase and glucosidase. In addition, we evaluated the effects of AP on absorption of orally administered olive oil, glucose, maltose, sucrose and starch solution in mice. We found that AP concentration-dependently inhibited the activity of lipase, maltase and sucrase with an IC50 of 0.95, 0.22 and 0.60 mg ml−1, respectively. In ICR mice, olive oil was administered orally immediately after oral administration of AP solution, and plasma triglyceride concentration was measured. We found that AP significantly inhibited the rise in plasma triglyceride concentration after olive oil loading. AP also significantly inhibited the rise in plasma glucose concentration after maltose and sucrose loading, and this effect was more potent against maltose. AP also inhibited the rise in plasma glucose concentration after glucose loading and slightly inhibited it after starch loading. Our results suggest that AP inhibits lipase and glucosidase activities, which leads to a reduction in the intestinal absorption of lipids and carbohydrates.

  16. Nitrogen uptake by Eucalyptus regnans and Acacia spp. - preferences, resource overlap and energetic costs.

    Science.gov (United States)

    Pfautsch, Sebastian; Rennenberg, Heinz; Bell, Tina L; Adams, Mark A

    2009-03-01

    In southeastern Australia, the overstory species Eucalyptus regnans F. Muell. commonly grows with either of the two leguminous understory trees, Acacia melanoxylon (R. Br. Ex Ait. f.) or Acacia dealbata (Link.). Our objective was to elucidate interactions between the dominant eucalypt and its companion acacias for nitrogen (N) sources. Use of stable N isotopes as tracers revealed that ammonium was the preferred soil N source for all species, nevertheless, total N uptake varied greatly among species. Studies with double-labeled ((13)C/(15)N) glutamine indicated the uptake of this form of organic N in small amounts by both E. regnans and the Acacia spp. These and other data imply that, in contrast to boreal forests, organic N is not a significant component of N nutrition in mountain ash forests. Field and laboratory studies provided evidence that N(2)-fixation capacity of acacias varies with stand development, with N-fixing species playing an important role in N nutrition during the early but not the mature stages of forest growth. An index of N-uptake efficiency - the amount of oxygen consumed per unit N taken up - was compared across four N sources and three species. Nitrate uptake was the least efficient form of N acquisition, especially compared with ammonium uptake which was up to 30-fold less costly. Efficiency of glutamine uptake was intermediate between that of ammonium and nitrate. Differences in uptake efficiency among N forms were most pronounced for the Acacia spp. and least for E. regnans. We conclude that an overlap in requirements among sympatric Acacia spp. and E. regnans for specific soil N sources can be bypassed because of changes in biochemical strategies of Acacia spp. triggered by increasing soil N concentrations during stand development. Further studies might elucidate whether this is a common feature of complex forest ecosystems, or a specialty of the interaction between eucalypts and acacias.

  17. Litter-forager termite mounds enhance the ectomycorrhizal symbiosis between Acacia holosericea A. Cunn. Ex G. Don and Scleroderma dictyosporum isolates.

    Science.gov (United States)

    Duponnois, Robin; Assikbetse, Komi; Ramanankierana, Heriniaina; Kisa, Marija; Thioulouse, Jean; Lepage, Michel

    2006-05-01

    The hypothesis of the present study was that the termite mounds of Macrotermes subhyalinus (MS) (a litter-forager termite) were inhabited by a specific microflora that could enhance with the ectomycorrhizal fungal development. We tested the effect of this feeding group mound material on (i) the ectomycorrhization symbiosis between Acacia holosericea (an Australian Acacia introduced in the sahelian areas) and two ectomycorrhizal fungal isolates of Scleroderma dictyosporum (IR408 and IR412) in greenhouse conditions, (ii) the functional diversity of soil microflora and (iii) the diversity of fluorescent pseudomonads. The results showed that the termite mound amendment significantly increased the ectomycorrhizal expansion. MS mound amendment and ectomycorrhizal inoculation induced strong modifications of the soil functional microbial diversity by promoting the multiplication of carboxylic acid catabolizing microorganisms. The phylogenetic analysis showed that fluorescent pseudomonads mostly belong to the Pseudomonads monteillii species. One of these, P. monteillii isolate KR9, increased the ectomycorrhizal development between S. dictyosporum IR412 and A. holosericea. The occurrence of MS termite mounds could be involved in the expansion of ectomycorrhizal symbiosis and could be implicated in nutrient flow and local diversity.

  18. Lenho e Casca de Eucalyptus e Acacia em Plantios Monoespecíficos e Consorciados

    OpenAIRE

    Silva, Camila Luiz; Roldão, Bruna de Carvalho; Santos, Leonardo David Tuffi; Hein, Paulo Ricardo Gherardi

    2017-01-01

    RESUMO O objetivo deste estudo foi avaliar a variação do teor e espessura da casca e da densidade básica da madeira de Eucalyptus e Acacia plantados em monocultivo e consórcio. Cinco árvores de Eucalyptus urophylla × E. grandis e cinco de Acacia mangium foram investigadas em plantios monoespecíficos e mistos, totalizando 20 árvores. O teor e espessura da casca produzida pela Acacia em monocultivo (47,5% e 1,32 cm) foram aproximadamente três vezes superiores, quando comparadas àquelas do plant...

  19. Dam Break Analysis of Embankment Dams Considering Breach Characteristics

    Directory of Open Access Journals (Sweden)

    Abolfazl Shamsaei

    2004-05-01

    Full Text Available The study of dam's break, needs the definition of various parameters such as the break cause, its type, its dimension and the duration of breach development. The precise forecast for different aspects of the breach is one of the most important factors for analyzing it in embankment dam. The characteristics of the breach and determination of their vulnerability has the most effect on the waves resulting from dam break. Investigating, about the parameters of the breach in "Silveh" earth dam have been determined using the suitable model. In Silve dam a trapezoid breach with side slope z=0.01m and the average base line b=80m was computed. The duration of the breaches development is 1.9 hour. Regarding the above results and the application of DAM Break software the consequences of the probable break of the dam was determined. The analysis of the results of water covering of the city of Piranshahr located 12km from silve dam confirms that in 3 hours the water will reach the height (level of 1425 meters.

  20. Some aspects of fisheries ecology in Thomas dam, Kano Nigeria ...

    African Journals Online (AJOL)

    The diversity, length-weight relationship and condition factor of fish species of Thomas Dam, Dambatta Kano were studied fortnightly between November, 2016 and February, 2017. Fish species were collected using line nets, cast nets, hooks and traps; weighted to the nearest gram and standard length measured to the ...

  1. War damages and reconstruction of Peruca dam

    International Nuclear Information System (INIS)

    Nonveiller, E.; Sever, Z.

    1999-01-01

    The paper describes the heavy damages caused by blasting in the Peruca rockfill dam in Croatia in January 1993. Complete collapse of the dam by overtopping was prevented through quick action of the dam owner by dumping clayey gravel on the lowest sections of the dam crest and opening the bottom outlet of the reservoir, thus efficiently lowering the water level. After the damages were sufficiently established and alternatives for restoration of the dam were evaluated, it was decided to construct a diaphragm wall through the damaged core in the central dam part as the impermeable dam element and to rebuild the central clay core at the dam abutments. Reconstruction works are described

  2. Dam construction in salt formations

    International Nuclear Information System (INIS)

    Jezierski, H.

    1984-01-01

    Dam Construction is a key task for the safety of the Gorleben repository. In order to seal a fille disposal field from the part in operation and to minimize radionuclide migration during the post-operating time a dam is to be developed and tested under certain accident conditions i.e., mainly the intrusion of brines and natural gas from either side of the dam. The development of this dam is subject of an extensive engineering project. This report summarizes the goals, problems, concepts, and first results of these systematical project studies. By analysing and characterizing special design criteria under site-specific aspects the major development priorities are investigated. First results will be presented concerning concrete based materials and their property changes due to the corrosive behavior of brines at elevated temperatures. Based on these investigations, pilot dams will be built and tested to prove their efficiency

  3. Intercropping Acacia mangium stimulates AMF colonization and soil phosphatase activity in Eucalyptus grandis

    Directory of Open Access Journals (Sweden)

    Daniel Bini

    Full Text Available ABSTRACT: Arbuscular mycorrhizal fungi (AMF are very important to plant nutrition, mostly in terms of acquisition of P and micronutrients. While Acacia mangium is closely associated with AMF throughout the whole cycle, Eucalyptus grandis presents this symbiosis primarily at the seedling stage. The aim of this study was to evaluate the dynamics of AMF in these two tree species in both pure and mixed plantations during the first 20 months after planting. We evaluated the abundance, richness and diversity of AMF spores, the rate of AMF mycorrhizal root colonization, enzymatic activity and soil and litter C, N and P. There was an increase in AMF root colonization of E. grandis when intercropped with A. mangium as well as an increase in the activity of acid and alkaline phosphatase in the presence of leguminous trees. AMF colonization and phosphatase activities were both involved in improvements in P cycling and P nutrition in soil. In addition, P cycling was favored in the intercropped plantation, which showed negative correlation with litter C/N and C/P ratios and positive correlation with soil acid phosphatase activity and soil N and P concentrations. Intercropping A. mangium and E. grandis maximized AMF root colonization of E. grandis and phosphatase activity in the soil, both of which accelerate P cycling and forest performance.

  4. Acaciaside-B-enriched fraction of Acacia auriculiformis is a prospective spermicide with no mutagenic property.

    Science.gov (United States)

    Pal, Durba; Chakraborty, Pratip; Ray, H N; Pal, B C; Mitra, Debashis; Kabir, Syed N

    2009-09-01

    As a part of our continued venture to develop a safe and effective spermicide, we have identified a triterpene glycoside (Acaciaside-B (Ac-B))-enriched fraction (Ac-B-en) isolated from the seeds of Acacia auriculiformis and evaluated its spermicidal potential in vitro. Sperm motility was completely inhibited within 20 s at a minimum effective concentration (MEC) of 120 microg/ml. Tests for sperm viability by dual fluoroprobe staining showed the effect to be spermicidal with an EC(50) of 35.20 microg/ml. A series of investigations including tests for hypo-osmotic swelling, membrane lipid peroxidation, and electron microscopy document that the spermicidal effect of the fraction involves loss of sperm plasma membrane integrity and dissolution of the acrosomal vesicle--the two most important structural components that play diverse roles in physiological functions of sperm including fertilization. The fraction at 10 x MEC exerted no detrimental effects on in vitro growth of Lactobacillus acidophilus, which is considered the major constituent of vaginal microflora that maintains vaginal health. Ames tests performed with different strains of Salmonella typhimurium including TA 97a, 98, 100, and 102, which detect mutagens causing bp substitution or frameshifting at G-C or A-T bp, demonstrate no mutagenic potential of the fraction. Significant spermicidal potential with no possible mutagenic effect and adverse impacts on lactobacilli growth attests to the credential of Ac-B-en as a prospective future spermicide for the development of a safe and effective vaginal contraceptive formulation.

  5. Soil nutritional status and biogeography influence rhizosphere microbial communities associated with the invasive tree Acacia dealbata.

    Science.gov (United States)

    Kamutando, Casper N; Vikram, Surendra; Kamgan-Nkuekam, Gilbert; Makhalanyane, Thulani P; Greve, Michelle; Roux, Johannes J Le; Richardson, David M; Cowan, Don; Valverde, Angel

    2017-07-26

    Invasiveness and the impacts of introduced plants are known to be mediated by plant-microbe interactions. Yet, the microbial communities associated with invasive plants are generally poorly understood. Here we report on the first comprehensive investigation of the bacterial and fungal communities inhabiting the rhizosphere and the surrounding bulk soil of a widespread invasive tree, Acacia dealbata. Amplicon sequencing data indicated that rhizospheric microbial communities differed significantly in structure and composition from those of the bulk soil. Two bacterial (Alphaproteobacteria and Gammaproteobacteria) and two fungal (Pezizomycetes and Agaricomycetes) classes were enriched in the rhizosphere compared with bulk soils. Changes in nutritional status, possibly induced by A. dealbata, primarily shaped rhizosphere soil communities. Despite a high degree of geographic variability in the diversity and composition of microbial communities, invasive A. dealbata populations shared a core of bacterial and fungal taxa, some of which are known to be involved in N and P cycling, while others are regarded as plant pathogens. Shotgun metagenomic analysis also showed that several functional genes related to plant growth promotion were overrepresented in the rhizospheres of A. dealbata. Overall, results suggest that rhizosphere microbes may contribute to the widespread success of this invader in novel environments.

  6. Inhibition of iron induced lipid peroxidation and antioxidant activity of Indian spices and Acacia in vitro.

    Science.gov (United States)

    Yadav, Amit Singh; Bhatnagar, Deepak

    2010-03-01

    The spices used in the Indian foods such as Star anise (Illicium verum), Bay leaves (Cinnamomum zeylanicum) and Cobra's saffron (Mesua ferrea), and Acacia (Acacia catechu), which have medicinal value, were used as test samples, to find their effect on in vitro lipid peroxidation (LPO). Rat liver post mitochondrial supernatant (PMS) in Tris HCl buffer, pH 7.4 was incubated for 0 and 1 h, with various test extracts in three different oxidant systems. The results show that addition of test samples to FeCl(3) medium at 0 h significantly stop the initiation of the LPO. However, the propagation phase of LPO was inhibited by Cobra's saffron and Acacia and not by Star anise and Bay leaves. The test samples also showed strong reducing power and superoxide radical scavenging activity. Cobra's saffron and Acacia showed the highest antioxidant activity, probably due to the higher polyphenol content as compared to other test samples.

  7. A preliminary report on decay and canker of Acacia richii caused by Inonotus rickii in China

    Czech Academy of Sciences Publication Activity Database

    Cui, B.K.; Zhao, C.L.; Vlasák, Josef; Dai, Y.C.

    2014-01-01

    Roč. 44, č. 1 (2014), s. 82-84 ISSN 1437-4781 Institutional support: RVO:60077344 Keywords : wood-decaying fungus * Inonotus rickii * Acacia richii Subject RIV: GK - Forest ry Impact factor: 1.373, year: 2014

  8. Controlled dual release study of curcumin and a 4-aminoquinoline analog from gum acacia containing hydrogels

    CSIR Research Space (South Africa)

    Aderibigbe, BA

    2014-10-01

    Full Text Available The potential of gum acacia containing hydrogels as controlled dual-drug delivery systems for antiprotozoal agents was investigated. 4-Aminoquinoline analog and curcumin were selected as model drugs because they exhibit antiprotozoal activity...

  9. Assessing the impacts of Acacia mearnsii on grazing provision and livestock production

    CSIR Research Space (South Africa)

    Yapi, T

    2012-10-01

    Full Text Available In this presentation the author shares some of his MSc research findings to highlight the effects of Acacia mearnsii density and clearing on grazing provision and related resources....

  10. Antifungal Activity from Leaves of Acacia Nilotica against Pythium Aphanidermatum

    Directory of Open Access Journals (Sweden)

    A. J. Khan

    1996-01-01

    Full Text Available Gallic acid and methyl ester of gallic acid has been identified as antifungal compounds against the mycelial growth of Pythium aphanidermatum from acetone-water extracts of Acacia nilotica leaves. The growth of fungus was completely ceased by gallic acid and its methyl ester at 1000 ppm and 750 ppm, respectively. Antifungal properties of both compounds were found to be higher in combination than alone. The minimum inhibitory concentration for both compounds was 1000 ppm. No phytotoxic effect of the compounds was observed on watermelon seed germination. The growth of roots and shoots of watermelon seedlings was promoted by gallic acid but decreased with methyl ester of gallic acid. Nitrate reductase activity of the fungus was significantly inhibited by both compounds.

  11. PRODUCTION OF MANGIUM (Acacia mangium) WOOD VINEGAR AND ITS UTILIZATION

    OpenAIRE

    Nurhayati Tjutju; Roliadi Han; Bermawie Nurliani

    2005-01-01

    Production  of  wood vinegar from mangium (Acacia  mangium) wood bolts/pieces  with their diameter of 3  17 cm, length of 30  67 cm, moisture content of 84.4%, and specific gravity of 0.52 conducted in a dome-shaped kiln with 1.2 m'-capacity afforded a yield of 40.3%.   The mangium wood vinegar was produced  through condensation  (cooling) of  smoke/gas fractions released during the charcoaling (carbonization) process  of  mangium wood.    The  process  could be regarded  as an integrated pro...

  12. Tannins quantification in barks of Mimosa tenuiflora and Acacia mearnsii

    Directory of Open Access Journals (Sweden)

    Leandro Calegari

    2016-03-01

    Full Text Available Due to its chemical complexity, there are several methodologies for vegetable tannins quantification. Thus, this work aims at quantifying both tannin and non-tannin substances present in the barks of Mimosa tenuiflora and Acacia mearnsii by two different methods. From bark particles of both species, analytical solutions were produced by using a steam-jacketed extractor. The solution was analyzed by Stiasny and hide-powder (no chromed methods. For both species, tannin levels were superior when analyzed by hide-powder method, reaching 47.8% and 24.1% for A. mearnsii and M. tenuiflora, respectively. By Stiasny method, the tannins levels considered were 39.0% for A. mearnsii, and 15.5% for M. tenuiflora. Despite the best results presented by A. mearnsii, the bark of M. tenuiflora also showed great potential due to its considerable amount of tannin and the availability of the species at Caatinga biome.

  13. The Importance of Acacia Trees for Insectivorous Bats and Arthropods in the Arava Desert

    Science.gov (United States)

    Hackett, Talya D.; Korine, Carmi; Holderied, Marc W.

    2013-01-01

    Anthropogenic habitat modification often has a profound negative impact on the flora and fauna of an ecosystem. In parts of the Middle East, ephemeral rivers (wadis) are characterised by stands of acacia trees. Green, flourishing assemblages of these trees are in decline in several countries, most likely due to human-induced water stress and habitat changes. We examined the importance of healthy acacia stands for bats and their arthropod prey in comparison to other natural and artificial habitats available in the Arava desert of Israel. We assessed bat activity and species richness through acoustic monitoring for entire nights and concurrently collected arthropods using light and pit traps. Dense green stands of acacia trees were the most important natural desert habitat for insectivorous bats. Irrigated gardens and parks in villages and fields of date palms had high arthropod levels but only village sites rivalled acacia trees in bat activity level. We confirmed up to 13 bat species around a single patch of acacia trees; one of the richest sites in any natural desert habitat in Israel. Some bat species utilised artificial sites; others were found almost exclusively in natural habitats. Two rare species (Barbastella leucomelas and Nycteris thebaica) were identified solely around acacia trees. We provide strong evidence that acacia trees are of unique importance to the community of insectivorous desert-dwelling bats, and that the health of the trees is crucial to their value as a foraging resource. Consequently, conservation efforts for acacia habitats, and in particular for the green more densely packed stands of trees, need to increase to protect this vital habitat for an entire community of protected bats. PMID:23441145

  14. Potensi Cuka Kayu dari Eucalyptus Pellita dan Acacia Mangium Wild sebagai Antimikroba

    OpenAIRE

    ', Sudarnyoto; Johan, Vonny Setiaries; ', Rahmayuni

    2014-01-01

    Waste timber during logging Eucalyptus pellitaand Acacia mangium Wild from plant forest industry has not been in use, where it can processing as wood vinegar. The purposed of this study were to obtain wood vinegar from Eucalyptus pellita and Acacia mangium Wild and determine the antimicrobial activity from both wood vinegar. Antimicrobial activity conducted with view clear zone around the paper disc soaked in vinegar on a medium Nutrient Agarcontains microbial pathogens Staphylococcus aureus ...

  15. Mangrove endophyte promotes reforestation tree (Acacia polyphylla) growth.

    Science.gov (United States)

    Castro, Renata Assis; Dourado, Manuella Nóbrega; Almeida, Jaqueline Raquel de; Lacava, Paulo Teixeira; Nave, André; Melo, Itamar Soares de; Azevedo, João Lucio de; Quecine, Maria Carolina

    Mangroves are ecosystems located in the transition zone between land and sea that serve as a potential source of biotechnological resources. Brazil's extensive coast contains one of the largest mangrove forests in the world (encompassing an area of 25,000km 2 along all the coast). Endophytic bacteria were isolated from the following three plant species: Rhizophora mangle, Laguncularia racemosa and Avicennia nitida. A large number of these isolates, 115 in total, were evaluated for their ability to fix nitrogen and solubilize phosphorous. Bacteria that tested positive for both of these tests were examined further to determine their level of indole acetic acid production. Two strains with high indole acetic acid production were selected for use as inoculants for reforestation trees, and then the growth of the plants was evaluated under field conditions. The bacterium Pseudomonas fluorescens (strain MCR1.10) had a low phosphorus solubilization index, while this index was higher in the other strain used, Enterobacter sp. (strain MCR1.48). We used the reforestation tree Acacia polyphylla. The results indicate that inoculation with the MCR1.48 endophyte increases Acacia polyphylla shoot dry mass, demonstrating that this strain effectively promotes the plant's growth and fitness, which can be used in the seedling production of this tree. Therefore, we successfully screened the biotechnological potential of endophyte isolates from mangrove, with a focus on plant growth promotion, and selected a strain able to provide limited nutrients and hormones for in plant growth. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  16. The World Commission on Dams + 10: Revisiting the Large Dam Controversy

    Directory of Open Access Journals (Sweden)

    Deborah Moore

    2010-06-01

    Full Text Available The World Commission on Dams (WCD was an experiment in multi-stakeholder dialogue and global governance concerned with a subject area – large dams – that was fraught with conflict and controversy. The WCD Report, Dams and Development: A New Framework for Decision-Making, was published in 2000 and accompanied by hopes that broad-based agreements would be forged on how to better manage water and energy development. Ten years later, this special issue of Water Alternatives revisits the WCD and its impacts, exploring the question: Is the WCD still relevant? The editorial team and the Guest Editors of this special issue of Water Alternatives have selected a range of 20 papers, 6 viewpoints, and 4 book reviews that help to illustrate the evolution in the dams debate. The goal of this special issue is to examine the influence and the impacts of the WCD on the dam enterprise, in general, and on the policies and practices of key stakeholders and institutions, and on the development outcomes for affected communities and environments, in particular. In this introduction, the Guest Editors provide an overview of the special issue, exploring the new drivers of dam development that have emerged during the last decade, including climate change and new financiers of dams, and describing the themes emerging from this diverse set of papers and viewpoints. This special issue demonstrates the need for a renewed multi-stakeholder dialogue at multiple levels. This would not be a redo of the WCD, but rather a rekindling and redesigning of processes and forums where mutual understanding, information-sharing, and norm-setting can occur. One of the most promising developments of the last decade is the further demonstration, in case studies described here, that true partnership amongst key stakeholders can produce transformative resource-sharing agreements, showing that many of the WCD recommendations around negotiated decision making are working in practice. We hope

  17. Anatomia da madeira de Acacia bonariensis Gill. ex Hook. et Arn. Wood anatomy of Acacia bonariensis Gill. ex Hook. et Arn.

    Directory of Open Access Journals (Sweden)

    José Newton Cardoso Marchiori

    1996-08-01

    Full Text Available O objetivo do presente trabalho é a descrição anatômica da madeira de Acacia bonariensis Gill. Hook. et Arn. A estrutura anatômica é comparada com outras espécies sul-brasileiras do mesmo gênero. A presença de raios multisseriados estreitos e fibras septadas permitem classificar a espécie na série Vulgares Bentham ou sub-gênero Aculeiferum Vassal.The wood anatomy of Acacia bonariensis Gill. ex Hook. et Arn. is described and compared with other south-american Acacias. The presence of narrow multisseriate rays and libriform fibres, observed in the wood, are commonly found among species of the series Vulgares Benth. or sub-genus Aculeiferum Vassal.

  18. Preparation and physicochemical properties of protein concentrate and isolate produced fromAcacia tortilis(Forssk.) Hayne ssp.raddiana.

    Science.gov (United States)

    Embaby, Hassan E; Swailam, Hesham M; Rayan, Ahmed M

    2018-02-01

    The composition and physicochemical properties of defatted acacia flour (DFAF), acacia protein concentrate (APC) and acacia protein isolate (API) were evaluated. The results indicated that API had lower, ash and fat content, than DFAF and APC. Also, significant difference in protein content was noticed among DFAF, APC and API (37.5, 63.7 and 91.8%, respectively). Acacia protein concentrate and isolates were good sources of essential amino acids except cystine and methionine. The physicochemical and functional properties of acacia protein improved with the processing of acacia into protein concentrate and protein isolate. The results of scanning electron micrographs showed that DFAF had a compact structure; protein concentrate were, flaky, and porous type, and protein isolate had intact flakes morphology.

  19. Effect of acacia (Robinia pseudo-acacia L.) honey on the characteristic microflora of yogurt during refrigerated storage.

    Science.gov (United States)

    Varga, László

    2006-04-25

    The primary purpose of this research was to monitor the influence of acacia honey addition to yogurt milk on survival of the microbial flora of yogurt during refrigerated storage for 6 wk. Results showed that the presence of honey at 1.0% to 5.0% (w/v) did not significantly influence (P>0.05) the viability of characteristic microorganisms (i.e., Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) in yogurt during storage at 4 degrees C. Similarly, honey had no effect on pH and lactic acid levels of the final products. Despite these findings, enrichment of yogurt with honey is recommended because honey is a natural sweetener that possesses a wide range of beneficial nutritional properties. In addition, at a rate of approximately 3.0% (w/v), it highly improves the sensory quality of the finished product without having a detrimental effect on characteristic lactic acid bacteria.

  20. Análise faunística de abelhas Euglossina (Hymenoptera: Apidae em ambientes de floresta nativa e plantios de Acacia mangium no Estado de Roraima. = Faunal analysis of the Euglossina bees (Hymenoptera: Apidae within the native Forest and plantations of Acacia mangium in the Brazilian State of Roraima.

    Directory of Open Access Journals (Sweden)

    Sheila Fernandes Tavares Maia

    2008-12-01

    single day, resulting in a total of 6 days of collection between all collection sites. One hundredand twenty three bees 21 species were collected. At the collection points of the plantations of Acacia mangium 35 bees from 12 species were collected, while in the native forest 88 bees from 17 species were obtained. The most abundant species were Eulaema pseudocingulata (48 specimens, Eul. meriana (12 specimens, Eul. cingulata (11 specimens, Euglossa augaspis (10 specimens and Eug. Amazonica (8 specimens. The collection points of Acacia mangium plantations presented low diversity and abundance when compared with the collection areas from the native forest.

  1. Seismic Fortification Analysis of the Guoduo Gravity Dam in Tibet, China

    Directory of Open Access Journals (Sweden)

    Peng Lin

    2015-01-01

    Full Text Available The primary aim of this research was to analyze the seismic performance of the Guoduo gravity dam. A nonlinear FEM method was implemented to study the deformation, stress, and overall stability of dam under both static and dynamic loading conditions, including both normal and overloading conditions. A dam seismic failure risk control method is proposed based on the cracking mechanism induced by the dynamic load to ensure dam safety and stability. Numerical simulation revealed that (1 under normal static and dynamic loading the symmetry of the displacement distributions is good, showing that the dam abutments and riverbed foundation have good overall stiffness. The stress distribution is a safe one for operation under both normal water loading and seismic loading. (2 Attention should be paid to the reinforcement design of outlets of the diversion dam monoliths, and enhance the capability of sustaining that tensile stress of dam monoliths. (3 The shape of the dam profile has a significant effect on the dynamic response of the dam. (4 By employing the “overload safety factor method,” the overall seismic fortification is as follows: K1=1.5, K2= 2~3, and K3= 3~4.

  2. Proceedings of the Canadian Dam Association's 2006 annual conference: dams: past, present and future

    International Nuclear Information System (INIS)

    2006-01-01

    This conference addressed particular technical challenges regarding the operation of dams with particular focus on best practices for improving dam management and safety. It featured 4 workshops and a technical program led by experts on dams and tailings facilities that addressed topics such as dam construction, design and rehabilitation; dam management in a hydrological uncertainty context; monitoring, instrumentation and maintenance; dam behaviour; dam safety, dam failure and practical approaches to emergency preparedness planning for dam owners; historical aspects and environmental issues and conflicting water use. Recent developments in dam construction were reviewed along with discharge and debris management, tailings dam issues, asset management, seismic issues, public safety, seepage monitoring, flow control, dam rehabilitation, concrete testing, hydrotechnical issues, risk assessment methodology, and dam safety guidelines for extreme flood analyses and their applications. All 80 presentations from this conference have been catalogued separately for inclusion in this database. refs., tabs., figs

  3. 7 CFR 1724.55 - Dam safety.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Dam safety. 1724.55 Section 1724.55 Agriculture... § 1724.55 Dam safety. (a) The provisions of this section apply only to RUS financed electric system... for Dam Safety,”(Guidelines), as applicable. A dam, as more fully defined in the Guidelines, is...

  4. Dam safety from theory to practice

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    These proceedings on dam safety consists of 20 papers divided into seven sessions. The first session dealt with tailings dams; sessions 2 to 5 with technology transfer as related to dam safety; the sixth session with dam rehabilitation; and the last session with environmental concerns. The conference took place at Banff, Alberta, in October 1995.refs., figs., tabs

  5. Perspectives on dam safety in Canada

    International Nuclear Information System (INIS)

    Halliday, R.

    2004-01-01

    Canadian dam safety issues were reviewed from the perspective of a water resources engineer who is not a dam safety practitioner. Several external factors affecting dam safety were identified along with perceived problems in dam safety administration. The author claims that the main weakness in safety practices can be attributed to provincial oversights and lack of federal engagement. Some additions to the Canadian Dam Safety Guidelines were proposed to address these weaknesses. Canada has hundreds of large dams and high hazard dams whose failure would result in severe downstream consequences. The safety of dams built on boundary waters shared with the United States have gained particular attention from the International Joint Commission. This paper also examined safety criteria for concerns such as aging dams, sabotage and global climate change that may compromise the safety of a dam. 26 refs

  6. Dams and Levees: Safety Risks

    Science.gov (United States)

    Carter, N. T.

    2017-12-01

    The nation's flood risk is increasing. The condition of U.S. dams and levees contributes to that risk. Dams and levee owners are responsible for the safety, maintenance, and rehabilitation of their facilities. Dams-Of the more than 90,000 dams in the United States, about 4% are federally owned and operated; 96% are owned by state and local governments, public utilities, or private companies. States regulate dams that are not federally owned. The number of high-hazard dams (i.e., dams whose failure would likely result in the loss of human life) has increased in the past decade. Roughly 1,780 state-regulated, high-hazard facilities with structural ratings of poor or unsatisfactory need rehabilitation. Levees-There are approximately 100,000 miles of levees in the nation; most levees are owned and maintained by municipalities and agricultural districts. Few states have levee safety programs. The U.S. Army Corps of Engineers (Corps) inspects 15,000 miles of levees, including levees that it owns and local levees participating in a federal program to assist with certain post-flood repairs. Information is limited on how regularly other levees are inspected. The consequence of a breach or failure is another aspect of risk. State and local governments have significant authority over land use and development, which can shape the social and economic impacts of a breach or failure; they also lead on emergency planning and related outreach. To date, federal dam and levee safety efforts have consisted primarily of (1) support for state dam safety standards and programs, (2) investments at federally owned dams and levees, and (3) since 2007, creation of a national levee database and enhanced efforts and procedures for Corps levee inspections and assessments. In Public Law 113-121, enacted in 2014, Congress (1) directed the Corps to develop voluntary guidelines for levee safety and an associated hazard potential classification system for levees, and (2) authorized support for the

  7. Effect of Linear Chain Carboxylic Acid Anhydrides on Physical and Mechanical Properties of Rubber (Hevea brasiliensis, Acacia, (Acacia spp., and Oil Palm (Tinnera spp. Woods

    Directory of Open Access Journals (Sweden)

    Mohd Afiq Mohtar

    2014-01-01

    Full Text Available The physical and mechanical properties of Rubber wood, Acacia wood, and Oil palm wood that reacted with acetic, propionic, and butyric anhydrides using a microwave heating for 4 minutes were investigated. A sample dimension of 300 mm × 100 mm × 25 mm (L×W×T was used for modification and they were cut into smaller specimens for different testing method. This study found that the density increment and void volume changes were not significantly different from anhydrides. The modification of wood with anhydrides was not significantly affected by the static bending properties, except for the Oil palm. The compression strength for any anhydrides shows an improvement for the Rubber wood and Acacia spp. but not Oil palm. The hardness was also not significantly different from anhydrides for all wood species. The impact strength of Rubber wood and Oil palm significantly increased compared to the untreated wood, but this was not the case for Acacia spp. Generally, the highest improvement in mechanical properties was obtained by modification of Rubber and Acacia woods with butyric anhydride.

  8. Abstracts and electronic proceedings of the Canadian Dam Association's 2008 annual conference : emerging technologies for dams

    International Nuclear Information System (INIS)

    2008-01-01

    This conference provided a national forum to explore and discuss emerging technologies which can be used to enhance dam safety and construction practices on both new and existing projects. Advancements in the fields of dam design, construction, and remedial works were reviewed as well as new techniques for dam monitoring programs. Engineers, geoscientists, dam owners and operators and other stakeholders exchanged ideas and information regarding the operation, maintenance and management of water and tailings dams. The conference sessions dealt with a variety of topics, including dam foundations; mining dams; dams and the environment; embankment dams; dams and seismicity; hydrotechnics; assessment and investigative technologies; dam instrumentation and monitoring; computational hydraulics; and dam safety. The conference featured 46 presentations, of which 37 have been catalogued separately for inclusion in this database. refs., tabs., figs

  9. Comparative study of microflora in Rhizospheric soils of Argania spinosa and Acacia raddiana of the arid zone from Oued El Ma (Tindouf)

    Science.gov (United States)

    Tissouras, Fatiha; Habib, Semira; Missoum, Malika; Louacini, Braim Kamel

    2016-04-01

    Desert soils occupy a large area in Algeria (80Moreover, exploitation of the Saharan soil microorganisms has several interests and especially in maintaining the ecological equilibrium of ecosystems. Unfortunately, few of microbiological studies have been conducted so far about the Saharan soil Algerian, with the exception of some work done on the desert soils in the region of Beni Ounif. This work falls within the framework of Project CNEPRU F02320100009. The study focuses on an evaluation of the main germs rhizosphere soils from Argania spinosa and Acacia raddiana of the region of Oued El-ma (wilaya of Tindouf), located in southwest Algeria, followed by physicochemical analysis of some parameters (soil texture, pH, moisture content, organic matter). The results reveal that both rhizosphere soils have a sandy silt texture of alkali pH, with very low water content slightly different. Organic material of the rate varies from 0.2 to 1The type of vegetation influences positively the quantity and the dynamics of microbial population. Indeed, the two soils have an interesting microbial diversity, with densities of azotobacters, fungi, aerobic bacteria and actinomycetes are very high, followed germs ammonifiants, nitrifying and denitrifying. In the presence of Argania spinosa the microbial growth is most important (6.53 × 107 germs /g soil), compared with Acacia raddiana (3.13 × 107 germs /g). This shows the stimulating effect of the vegetation on the increase in the rate of these microorganisms in the soil. Well as the strong Fitness of adaptation the microbial biomass to drought. Keywords: Argania spinoza; Acacia raddiana; rhizospheric soil; microbiology evaluation.

  10. Salinity tolerance potential of two acacia species at early seedling stage

    International Nuclear Information System (INIS)

    Abbas, G.; Saqib, M.; Akhtar, J.; Basra, S.M.A.

    2013-01-01

    Soil salinity is a major environmental issue in arid and semiarid regions of the world. Acacia has very important role for salt affected barren lands due to its high salinity tolerance potential. The aim of the present study was to explore the genetic differences among Acacia ampliceps and Acacia nilotica regarding their response to salinity. Three-weeks old seedlings of both species were transplanted in half strength Hoagland nutrient solution having five salt levels (control,100, 200, 300 and 400 mM NaCl) with four replications in completely randomized design with factorial arrangement. After eight weeks of transplantation, the plants were harvested and data for shoot and root length and their fresh and dry weights were recorded. Na/sup +/, K/sup +/ and Cl/sup -/concentration of both root and shoot was determined. All the growth parameters of both species declined significantly in response to salinity. Acacia ampliceps was more salt tolerant than Acacia nilotica with better growth owing to higher K/sup +/: Na/sup +/ ratio in plant tissues. (author)

  11. Clinical and microbiologic effects of commercially available gel and powder containing Acacia arabica on gingivitis.

    Science.gov (United States)

    Pradeep, A R; Agarwal, E; Bajaj, P; Naik, S B; Shanbhag, N; Uma, S R

    2012-09-01

    There is a need for an anti-plaque agent that can be used on a daily basis without the side effects of antibacterial chemicals such as chlorhexidine. The present study was designed to evaluate the clinical and microbiologic effects of commercially available gel and powder containing Acacia arabica in subjects with gingivitis. One hundred and twenty subjects with chronic generalized gingivitis were selected and randomly divided into four groups: Group 1 - placebo group; Group 2 -Acacia arabica gel group; Group 3 -Acacia arabica powder group; and Group 4 - 1% chlorhexidine gel group. Microbial counts of plaque samples, the gingival index of Loe and Silness and the plaque index were evaluated at baseline, 6 weeks, 12 weeks and 24 weeks. Microbial counts of plaque samples were evaluated at all visits. Acacia arabica gel and powder showed significant clinical improvement in gingival and plaque index scores as compared to a placebo. This improvement was comparable to 1% chlorhexidine gel. The difference between gel and powder with regard to clinical and microbiological parameters was not found to be significant at any time interval. Both Acacia arabica gel and powder may be useful herbal formulations for chemical plaque control in subjects with gingivitis. © 2012 Australian Dental Association.

  12. Antiatherosclerotic and Cardioprotective Potential of Acacia senegal Seeds in Diet-Induced Atherosclerosis in Rabbits

    Directory of Open Access Journals (Sweden)

    Heera Ram

    2014-01-01

    Full Text Available Acacia senegal L. (Fabaceae seeds are essential ingredient of “Pachkutta,” a specific Rajasthani traditional food. The present study explored antiatherosclerotic and cardioprotective potential of Acacia senegal seed extract, if any, in hypercholesterolemic diet-induced atherosclerosis in rabbits. Atherosclerosis in rabbits was induced by feeding normal diet supplemented with oral administration of cholesterol (500 mg/kg body weight/day mixed with coconut oil for 15 days. Circulating total cholesterol (TC, HDL-cholesterol (HDL-C, LDL-cholesterol (LDL-C, triglycerides, and VLDL-cholesterol (VLDL-C levels; atherogenic index (AI; cardiac lipid peroxidation (LPO; planimetric studies of aortal wall; and histopathological studies of heart, aorta, kidney, and liver were performed. Apart from reduced atherosclerotic plaques in aorta (6.34±0.72 and increased lumen volume (51.65±3.66, administration with ethanolic extract of Acacia senegal seeds (500 mg/kg/day, p.o. for 45 days to atherosclerotic rabbits significantly lowered serum TC, LDL-C, triglyceride, and VLDL-C levels and atherogenic index as compared to control. Atherogenic diet-induced cardiac LPO and histopathological abnormalities in aorta wall, heart, kidney, and liver were reverted to normalcy by Acacia senegal seed extract administration. The findings of the present study reveal that Acacia senegal seed extract ameliorated diet-induced atherosclerosis and could be considered as lead in the development of novel therapeutics.

  13. Lenho e Casca de Eucalyptus e Acacia em Plantios Monoespecíficos e Consorciados

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    Camila Luiz Silva

    2017-11-01

    Full Text Available RESUMO O objetivo deste estudo foi avaliar a variação do teor e espessura da casca e da densidade básica da madeira de Eucalyptus e Acacia plantados em monocultivo e consórcio. Cinco árvores de Eucalyptus urophylla × E. grandis e cinco de Acacia mangium foram investigadas em plantios monoespecíficos e mistos, totalizando 20 árvores. O teor e espessura da casca produzida pela Acacia em monocultivo (47,5% e 1,32 cm foram aproximadamente três vezes superiores, quando comparadas àquelas do plantio consorciado (15,2% e 0,51 cm. A partir desses resultados, conclui-se que não há diferença significativa entre as médias da densidade básica das madeiras de Eucalyptus e Acacia provenientes dos plantios monoespecíficos e mistos. Contudo, há variação longitudinal significativa em termos de densidade básica da madeira das árvores de Acacia e de Eucalyptus provenientes tanto do plantio monocultivado como do consorciado, indicando que há diferença na qualidade da madeira manejada para uso múltiplo.

  14. Cellulose nanocrystals from acacia bark-Influence of solvent extraction.

    Science.gov (United States)

    Taflick, Ticiane; Schwendler, Luana A; Rosa, Simone M L; Bica, Clara I D; Nachtigall, Sônia M B

    2017-08-01

    The isolation of cellulose nanocrystals from different lignocellulosic materials has shown increased interest in academic and technological research. These materials have excellent mechanical properties and can be used as nanofillers for polymer composites as well as transparent films for various applications. In this work, cellulose isolation was performed following an environmental friendly procedure without chlorine. Cellulose nanocrystals were isolated from the exhausted acacia bark (after the industrial process of extracting tannin) with the objective of evaluating the effect of the solvent extraction steps on the characteristics of cellulose and cellulose nanocrystals. It was also assessed the effect of acid hydrolysis time on the thermal stability, morphology and size of the nanocrystals, through TGA, TEM and light scattering analyses. It was concluded that the extraction step with solvents was important in the isolation of cellulose, but irrelevant in the isolation of cellulose nanocrystals. Light scattering experiments indicated that 30min of hydrolysis was long enough for the isolation of cellulose nanocrystals. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Acacia honey accelerates in vitro corneal ulcer wound healing model.

    Science.gov (United States)

    Abd Ghafar, Norzana; Ker-Woon, Choy; Hui, Chua Kien; Mohd Yusof, Yasmin Anum; Wan Ngah, Wan Zurinah

    2016-07-29

    The study aimed to evaluate the effects of Acacia honey (AH) on the migration, differentiation and healing properties of the cultured rabbit corneal fibroblasts. Stromal derived corneal fibroblasts from New Zealand White rabbit (n = 6) were isolated and cultured until passage 1. In vitro corneal ulcer was created using a 4 mm corneal trephine onto confluent cultures and treated with basal medium (FD), medium containing serum (FDS), with and without 0.025 % AH. Wound areas were recorded at day 0, 3 and 6 post wound creation. Genes and proteins associated with wound healing and differentiation such as aldehyde dehydrogenase (ALDH), vimentin, alpha-smooth muscle actin (α-SMA), collagen type I, lumican and matrix metalloproteinase 12 (MMP12) were evaluated using qRT-PCR and immunocytochemistry respectively. Cells cultured with AH-enriched FDS media achieved complete wound closure at day 6 post wound creation. The cells cultured in AH-enriched FDS media increased the expression of vimentin, collagen type I and lumican genes and decreased the ALDH, α-SMA and MMP12 gene expressions. Protein expression of ALDH, vimentin and α-SMA were in accordance with the gene expression analyses. These results demonstrated AH accelerate corneal fibroblasts migration and differentiation of the in vitro corneal ulcer model while increasing the genes and proteins associated with stromal wound healing.

  16. Field grown Acacia Mangium: how intensive is root growth?

    International Nuclear Information System (INIS)

    Wan Rasidah Kadir; Azizol Abdul Kadir; Van Cleemput, O.; Zaharah Abdul Rahman

    1998-01-01

    Under rainfed conditions, root development of trees can be very unpredictable and variable, depending on the amount and distribution of rainfall received. This becomes more critical when the rainfall is seasonal and the soil has a high clay content. Our investigation dealt with the root development of Acacia mangium established as plantation forest on a soil with heavy clay texture in Kemasul Forest Reserve, Malaysia. The distribution of active roots was measured at 9- and 21- month-old plantations using the radioactive P injection method. Growth at different distances from the tree base and at different soil depths was studied. After nine months of field planting, we found that roots were mostly concentrated at the surface within 1000 mm distance from the tree base. At one year after the first measurement, roots were traced as far as 6400 mm away. A large part of these roots, however, were detected within 3700 mm distance in the upper 300 mm soil. At this stage, roots can still did not go deeper than 450 mm depth, probably due to the high clay content at lower depth and low pH. This rapid root growth indicates that below-ground competition can be very intense if this species is established as a mixed-species plantation

  17. Phenolic Extracts from Acacia mangium Bark and Their Antioxidant Activities

    Directory of Open Access Journals (Sweden)

    Liangliang Zhang

    2010-05-01

    Full Text Available Phenolic compounds are present at very high concentrations in the bark of Acacia mangium. These compounds are known to have strong antioxidant activity and thus different beneficial effects on human health. Phenolic compounds in bark of A. mangium were extracted and their antioxidant activities were investigated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical-scavenging and ferric-reducing antioxidant power (FRAP assays. A central composite design has been employed to optimize the experimental conditions for a high total phenolic content and antioxidant activity. The desirability function approach has been employed to simultaneously optimize the three responses: total phenols, antiradical activity and FRAP. An extraction time of 90 min, liquid-solid ratio of 5, and temperature of 50 °C was predicted for the optimum experimental conditions using the desirability function. A significant linear relationship between antioxidant potency, antiradical activity and the content of phenolic compounds of bark extracts was observed. The structures of condensed tannins isolated from A. mangium were characterized by MALDI-TOF MS analyses. Condensed tannin oligomers from A. mangium were shown to be heterogeneous mixtures consisting of procyanidin and prodelphinidin structural units with polymerization degrees up to 9.

  18. Phenolic extracts from Acacia mangium bark and their antioxidant activities.

    Science.gov (United States)

    Zhang, Liangliang; Chen, Jiahong; Wang, Yongmei; Wu, Dongmei; Xu, Man

    2010-05-14

    Phenolic compounds are present at very high concentrations in the bark of Acacia mangium. These compounds are known to have strong antioxidant activity and thus different beneficial effects on human health. Phenolic compounds in bark of A. mangium were extracted and their antioxidant activities were investigated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging and ferric-reducing antioxidant power (FRAP) assays. A central composite design has been employed to optimize the experimental conditions for a high total phenolic content and antioxidant activity. The desirability function approach has been employed to simultaneously optimize the three responses: total phenols, antiradical activity and FRAP. An extraction time of 90 min, liquid-solid ratio of 5, and temperature of 50 degrees C was predicted for the optimum experimental conditions using the desirability function. A significant linear relationship between antioxidant potency, antiradical activity and the content of phenolic compounds of bark extracts was observed. The structures of condensed tannins isolated from A. mangium were characterized by MALDI-TOF MS analyses. Condensed tannin oligomers from A. mangium were shown to be heterogeneous mixtures consisting of procyanidin and prodelphinidin structural units with polymerization degrees up to 9.

  19. Impact of Dams on Riparian Frog Communities in the Southern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Rohit Naniwadekar

    2014-08-01

    Full Text Available The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat are poorly documented, and in particular the fate of frog populations is unknown. We examined the effects of dams on riparian frog communities in the Thamirabarani catchment in southern Western Ghats. We used nocturnal visual encounter surveys constrained for time, to document the species richness of frogs below and above the dam, and also at control sites in the same catchment. While we did not find differences in species richness below and above the dams, the frog community composition was significantly altered as a likely consequence of altered flow regime. The frog species compositions in control sites were similar to above-dam sites. Below-dam sites had a distinctly different species composition. Select endemic frog species appeared to be adversely impacted due to the dams. Below-dam sites had a greater proportion of generalist and widely distributed species. Dams in the Western Ghats appeared to adversely impact population of endemic species, particularly those belonging to the genus Nyctibatrachus that shows specialization for intact streams.

  20. Damming the rivers of the Amazon basin.

    Science.gov (United States)

    Latrubesse, Edgardo M; Arima, Eugenio Y; Dunne, Thomas; Park, Edward; Baker, Victor R; d'Horta, Fernando M; Wight, Charles; Wittmann, Florian; Zuanon, Jansen; Baker, Paul A; Ribas, Camila C; Norgaard, Richard B; Filizola, Naziano; Ansar, Atif; Flyvbjerg, Bent; Stevaux, Jose C

    2017-06-14

    More than a hundred hydropower dams have already been built in the Amazon basin and numerous proposals for further dam constructions are under consideration. The accumulated negative environmental effects of existing dams and proposed dams, if constructed, will trigger massive hydrophysical and biotic disturbances that will affect the Amazon basin's floodplains, estuary and sediment plume. We introduce a Dam Environmental Vulnerability Index to quantify the current and potential impacts of dams in the basin. The scale of foreseeable environmental degradation indicates the need for collective action among nations and states to avoid cumulative, far-reaching impacts. We suggest institutional innovations to assess and avoid the likely impoverishment of Amazon rivers.

  1. Fungal Succession and Decomposition of Acacia mangium Leaf Litters in Health and Ganoderma Attacked Standings

    Directory of Open Access Journals (Sweden)

    SAMINGAN

    2009-09-01

    Full Text Available Leaf litters of Acacia mangium play an important functional role in ecosystem, producing sources of nutrients and giving diversity of microorganisms. Understanding the variation in fungal populations in A. mangium forest is important due to the roles of fungi in regulating populations of other organisms and ecosystem processes. For these purposes, the tests were conducted under two years old of health standing (2S and Ganoderma attacked standing (2G using litterbag method. Litter weight loss and lignin, cellulose, C, N contents were measured each month during eight months of decomposition, as well as fungal community involved was observed. Litter weight loss and lignin, cellulose, C, N contents were measured each month during eight months of decomposition, as well as fungal community involved was observed. After eight months of decomposition, litter weight losses were low up to 34.61% (k = 0.7/year in 2S and 30.64% (k = 0.51/year in 2G, as well as lignin weight losses were low up to 20.05% in 2S and 13.87% in 2G. However, cellulose weight losses were 16.34% in 2S and 14.71% in 2G. In both standings, the numbers of fungal species were 21 and 20 respectively, while the total of fungal populations tends to increase after one month of decomposition and tend to decrease in the last three months. In the first and second months of decomposition fungal species were dominated by genera of Penicillium and Aspergillus and the last three months by Trichoderma, Phialophora, and Pythium.

  2. Effect of plant growth promoting rhizobia on seed germination and seedling traits in Acacia senegal

    Directory of Open Access Journals (Sweden)

    S.K. Singh

    2011-11-01

    Full Text Available Among arid zone tree species, Acacia senegal and Prosopis cineraria are the most important dryland resources of Western Rajasthan desert ecosystem. Due to ecological, biological and molecular similarities, they are often studied together. The climatic conditions in this region restrict the build-up of soil organic matter and soils are generally deficient in nitrogen. Studies were carried out to isolate and molecularly characterize the diverse group of plant growth promoting rhizobacteria from root nodules of native A. senegal and P. cineraria and their effect on seed germination and seedling traits in two genotypes of A. senegal. The direct sequencing of 16S rDNA region resulted in molecular identification of plant growth promoting rhizobacteria as Bacillus licheniformis, Sinorhizobium saheli isolated from root nodules of A. senegal and S. kostiense and S. saheli isolated from root nodules of P. cineraria. The partial sequences of 16S rDNA were assigned Gen accession numbers HQ738496, HQ738499, HQ738506 and HQ738508. Scarification treatment with sulphuric acid (98% for 15 minutes was able to break the exogenous seed dormancy and enhanced germination percentage in control treatment to 90% and 92.5% in A. senegal in genotypes CAZRI 113AS and CAZRI 35AS, respectively. The treatments with Bacillus licheniformis or S. kostiense, either inoculated individually or as coinoculants, had positive effect on phenotypic traits of germination. Two A. senegal genotypes exhibited significant differences with regard to all the phenotypic traits. On the other hand, treatments with S. saheli isolated from either A. senegal or P. cineraria had negative effects on germination and related phenotypic traits. Values of the coeffivient of determination (R2 over 80% for root length versus shoot length, root/shoot ratio and seedling weight respectively validate that the observed attributes are inter-dependable and linear progression trend can be predicted.

  3. Investigation of the rumen microbial community responsible for degradation of a putative toxin in Acacia angustissima

    International Nuclear Information System (INIS)

    Collins, E.M.C.; Blackall, L.L.; Mcsweeney, C.S.; Krause, D.O.

    2005-01-01

    Acacia angustissima has been proposed as a protein supplement in countries where availability of high quality fodder for grazing animals is a problem due to extreme, dry climates. While A. angustissima thrives in harsh environments and provides valuable nutrients required by ruminants, it has also been found to contain anti-nutritive factors that currently preclude its widespread application. A number of non-protein amino acids have been identified in the leaves of A. angustissima and in the past these have been linked to toxicity in ruminants. The non-protein amino acid 4-n-acetyl-2,4-diaminobutyric acid (ADAB) had been determined to be the major non-protein amino acid in the leaves of A. angustissima. Thus, in this study, the aim was to identify microorganisms from the rumen environment capable of degrading ADAB. Using an ADAB-containing plant extract, a mixed enrichment culture was obtained that exhibited substantial ADAB-degrading ability. Attempts to isolate an ADAB-degrading micro-organism were carried out, but no isolates were able to degrade ADAB in pure culture. The mixed microbial community of the ADAB-degrading enrichment culture was further examined through the use of pure-culture-independent techniques. Fluorescence in situ hybridization (FISH) was employed to investigate the diversity within this sample. In addition two bacterial 16S rDNA clone libraries were constructed in an attempt to further elucidate the members of the microbial population. The clone libraries were constructed from serial dilutions of the enrichment culture, a 10 -5 dilution where complete degradation of ADAB occurred, and a 10 -7 dilution where ADAB degradation did not occur. Through the comparison of these two libraries it was hypothesized that clones belonging to the Firmicutes phylum were involved in ADAB degradation. A FISH probe, ADAB1268, was then designed to target these clones and was applied to the enrichment cultures to investigate their relative abundance within the

  4. Group prepares guidelines for documenting dam performance

    International Nuclear Information System (INIS)

    McCann, M.W. Jr.

    1993-01-01

    The Association of State Dam Safety Officials and the Center on the Performance of Dams at Stanford University later this summer expect to complete guidelines for reporting the performance of state, federal, and private dams: A working group of state and federal dam safety engineers and consultants is developing the guidelines to identify incidents that should be reported and to establish reporting requirements. The Federal Emergency Management Agency (FEMA) is funding preparation and publication of the guidelines. The guidelines are expected to expedite the process for reporting information on dam incidents in a timely and complete manner. Much the same as the health care industry compiles and evaluates data related to the incidence of disease and the benefits of treatment, a single standard for reporting the performance of dams in the US will help create a national information base on the occurrence and consequence of dam incidents. Currently, incidents involving dam performance are not reported on a regular basis. The guidelines will define dam incidents in terms of events of engineering interest that provide insights to the safety and structural or operational integrity of dams. Examples of incidents include the performance of a dam that experiences ground motion from a large earthquake, extreme spillway or dam overtopping, rehabilitations made to satisfy dam safety requirements, embankment sliding of an earthen dam, and improper operations that leads to damage downstream. When an incident occurs, the satisfactory or unsatisfactory performance of a dam will be reported, either by a state dam safety official, the owner of the dam, or the owner's engineer

  5. Condensed tannins from acacia mangium bark: Characterization by spot tests and FTIR

    Science.gov (United States)

    Bharudin, Muhammad Azizi; Zakaria, Sarani; Chia, Chin Hua

    2013-11-01

    This paper describes the adaptation and evaluation of one chemical tests for tannins characterization in acacia mangium bark. Acid butanol test developed to identify respectively condensed tannins is described. The two traditional tests used for tannin characterization namely ferric test and vanillin test were also performed and their functional also discussed. Condensed tannins were extracted from acacia mangium bark using water medium in presence of three different concentration basic reagent of NaOH(5%,10% and 15%) and were characterized by FT-IR spectrometry.

  6. Dams and Obstructions along Iowa's Canoe Routes

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This dataset represents obstruction to canoe and boat users of the canoe routes of Iowa. This may represent actual dams, rock dams (natural or man made), large...

  7. Simulation of Breach Outflow for Earthfill Dam

    International Nuclear Information System (INIS)

    Razad, Azwin Zailti Abdul; Muda, Rahsidi Sabri; Sidek, Lariyah Mohd; Azia, Intan Shafilah Abdul; Mansor, Faezah Hanum; Yalit, Ruzaimei

    2013-01-01

    Dams have been built for many reasons such as irrigation, hydropower, flood mitigation, and water supply to support development for the benefit of human. However, the huge amount of water stored behind the dam can seriously pose adverse impacts to the downstream community should it be released due to unwanted dam break event. To minimise the potential loss of lives and property damages, a workable Emergency Response Plan is required to be developed. As part of a responsible dam owner and operator, TNB initiated a study on dam breach modelling for Cameron Highlands Hydroelectric Scheme to simulate the potential dam breach for Jor Dam. Prediction of dam breach parameters using the empirical equations of Froehlich and Macdonal-Langridge-Monopolis formed the basis of the modelling, coupled with MIKE 11 software to obtain the breach outflow due to Probable Maximum Flood (PMF). This paper will therefore discuss the model setup, simulation procedure and comparison of the prediction with existing equations.

  8. Douglas County Dam Breach Inundation Areas

    Data.gov (United States)

    Kansas Data Access and Support Center — Dam breach analysis provides a prediction of the extent and timing of flooding from a catastrophic breach of the dams. These results are sufficient for developing...

  9. Toxicological studies of aqueous extract of Acacia nilotica root

    Directory of Open Access Journals (Sweden)

    Alli Lukman Adewale

    2015-03-01

    Full Text Available Acacia nilotica is a widely used plant in traditional medical practice in Northern Nigeria and many African countries. The aim of this study was to determine the toxicological effects of a single dose (acute and of repeated doses (sub-acute administration of aqueous extract of A. nilotica root in rodents, following our earlier study on antiplasmodial activity. In the acute toxicity test, three groups of Swiss albino mice were orally administered aqueous extract of A. nilotica (50, 300 and 2000 mg/kg body weight and signs of toxicity were observed daily for 14 days. In the sub-acute toxicity study, four groups of 12 rats (6 male and 6 female were used. Group 1 received 10 ml/kg b.w distilled water (control, while groups 2, 3 and 4 received 125, 250 and 500 mg/kg b.w of the extract, respectively, for 28 consecutive days by oral gavage. Signs of toxicity/mortality, food and water intake and body weight changes were observed. Biochemical parameters were analysed in both plasma and liver homogenate. In the acute and sub-acute toxicity studies, the extract did not cause mortality. A significant reduction in the activity of lactate dehydrogenase was observed at 250 and 500 mg/kg b.w, while alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities were significantly higher than control values at 500 mg/kg b.w. The aqueous extract of A. nilotica was found to be safe in single dose administration in mice but repeated administration of doses higher than 250 mg/kg b.w of the extract for 28 days in rats may cause hepatotoxicity.

  10. Response of native soil microbial functions to the controlled mycorrhization of an exotic tree legume, Acacia holosericea in a Sahelian ecosystem.

    Science.gov (United States)

    Bilgo, Ablasse; Sangare, Sheikh K; Thioulouse, Jean; Prin, Yves; Hien, Victor; Galiana, Antoine; Baudoin, Ezekeil; Hafidi, Mohamed; Bâ, Amadou M; Duponnois, Robin

    2012-04-01

    Fifty years of overexploitation have disturbed most forests within Sahelian areas. Exotic fast growing trees (i.e., Australian Acacia species) have subsequently been introduced for soil improvement and fuelwood production purposes. Additionally, rhizobial or mycorrhizal symbioses have sometimes been favored by means of controlled inoculations to increase the performance of these exotic trees in such arid and semiarid zones. Large-scale anthropogenic introduction of exotic plants could also threaten the native biodiversity and ecosystem resilience. We carried out an experimental reforestation in Burkina Faso in order to study the effects of Acacia holosericea mycorrhizal inoculation on the soil nutrient content, microbial soil functionalities and mycorrhizal soil potential. Treatments consisted of uninoculated A. holosericea, preplanting fertilizer application and arbuscular mycorrhizal inoculation with Glomus intraradices. Our results showed that (i) arbuscular mycorrhizal (AM) inoculation and prefertilizer application significantly improved A. holosericea growth after 4 years of plantation and (ii) the introduction of A. holosericea trees significantly modified soil microbial functions. The results clearly showed that the use of exotic tree legume species should be directly responsible for important changes in soil microbiota with great disturbances in essential functions driven by microbial communities (e.g., catabolic diversity and C cycling, phosphatase activity and P availability). They also highlighted the importance of AM symbiosis in the functioning of soils and forest plantation performances. The AM effect on soil functions was significantly correlated with the enhanced mycorrhizal soil potential recorded in the AM inoculation treatment. © Springer-Verlag 2011

  11. Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution

    Science.gov (United States)

    Rangan, Haripriya; Fernandes, Manuel M.; Kull, Christian A.; Murphy, Daniel J.

    2017-01-01

    Acacia s.l. farnesiana, which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human-mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human-mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal for disjunct plant distributions. PMID:28484637

  12. WinDAM C earthen embankment internal erosion analysis software

    Science.gov (United States)

    Two primary causes of dam failure are overtopping and internal erosion. For the purpose of evaluating dam safety for existing earthen embankment dams and proposed earthen embankment dams, Windows Dam Analysis Modules C (WinDAM C) software will simulate either internal erosion or erosion resulting f...

  13. Dams life; La vie des barrages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The paper reports on the conclusions of decennial and annual inspections of French dams. Dams surveillance is performed by the operators and consists in visual examinations and measurements. Concrete dams, in particular, always have more or less developed fissures with water sweating threw the concrete mass or the foundations. Old concrete often show low swelling phenomena which are measured too. (J.S.)

  14. 76 FR 12094 - Whitman River Dam, Inc.

    Science.gov (United States)

    2011-03-04

    ... Dam, Inc. Notice of Application Tendered for Filing With the Commission and Soliciting Additional.... Project No.: 13237-002. c. Date Filed: February 14, 2011. d. Applicant: Whitman River Dam, Inc. e. Name of Project: Crocker Dam Hydro Project. f. Location: On the Whitman River, in the Town of Westminster...

  15. 78 FR 62627 - Sam Rayburn Dam Rate

    Science.gov (United States)

    2013-10-22

    ... DEPARTMENT OF ENERGY Southwestern Power Administration Sam Rayburn Dam Rate AGENCY: Southwestern... the power rate for the Sam Rayburn Dam (Rayburn) project pursuant to the Rayburn rate schedule (SRD-13..., Wholesale Rates for Hydro Power and Energy Sold to Sam Rayburn Dam Electric Cooperative, Inc. (Contract No...

  16. EVALUASI KEAMANAN DAM JATILUHUR BERBASIS INDEKS RESIKO

    Directory of Open Access Journals (Sweden)

    Avazbek Ishbaev

    2014-12-01

    Full Text Available The dams have very important roles to agricultural activities. Especially, West Java with 240,000 hectares of agricultural land, needs a good dam structure that can be used sustainably. Jatiluhur dam in Purwakarta, West Java is one of big dams in Indonesia which has important rules not only for Purwakarta but also for Jakarta, Karawang and Bekasi residents. A study and observation about safety and dam stability is needed to prevent any damage. The purpose of this research were to identify parameters that influenced dam safety and to evaluate dam reliability based on index tools. Analysis was done using risk index tools. The result showed that the condition of the dam of Jatiluhur is still satisfied with indicators, "Idam"-750. The total index risk was 127.22 and the safety factor was 83.04 out of 100. Therefore, Jatiluhur dam could be classified as safe and no need for particular treatments. Jatiluhur dam can be operated in normal condition or abnormal condition with periodic monitoring. Keywords: dam safety, evaluation, Jatiluhur Dam, risk index tools

  17. Effect of efficient microorganisms on cation exchange capacity in acacia seedlings (Acacia melanoxylon) for soil recovery in Mondonedo, Cundinamarca

    International Nuclear Information System (INIS)

    Diaz Barragan Olga Angelica; Montero Robayo Diana Mercedes; Lagos Caballero Jesus Alberto

    2009-01-01

    We determined the effect of efficient microorganisms (EM) on the cation exchange capacity for soil recovery in the municipality of Mondonedo, Cundinamarca. A greenhouse unit was installed in order to maintain stable conditions. After harvesting, sifted and homogenization of the soil sample, initial physical and chemical analyses were made. For the experimental units we used Acacia melanoxylon seedlings from Zabrinsky. A completely randomized design was done with eight treatments and three repetitions. For the maintenance and monitoring of the seedlings behaviour, a frequency of irrigation of three times per week was found. The application of the EM was done during three months: in the first month, it was applied four times (once a week); during the second month, it was applied twice (biweekly), and during the third month there was only one application. Additionally, every 15 days morphological analyses were made (number of leaves, branches and stem diameter). In the end, soil samples were taken from each plant pot. In the laboratory we analysed the cation exchange capacity, alkali ion exchange, saturation alkali, relations between elements and plant tissue. These were done using an atomic absorption spectrophotometer. Statistical analyses consisted on multiple comparisons test and variance tests, in order to find whether or not treatments exhibited significant differences. In that way, the best alternative for improving environmental quality of eroded soils as the Zabrinsky desert is the efficient microorganisms in 5% doses in irrigation water. Additionally, the cation exchange capacity must be enhanced using organic fertilizers (compost, mulch and gallinaza) in one pound doses, and chemical fertilizers: electrolytic Mn (0.0002 g), Cu (0.0002 g), Zn (0.0001 g), URFOS 44 (166.66 g) and klip-boro (5 g).

  18. Large dams and risk management

    International Nuclear Information System (INIS)

    Cazelais, N.

    2003-01-01

    In July 1996, Quebec's Saguenay region was subjected to intensive rainfall which caused severe floods and uncontrolled release of several reservoirs, resulting in extensive damage to dam structures and reservoirs. The probability of occurrence for that disaster was 1:10,000. Following the disaster, the Quebec government established a dam management body entitled the Commission scientifique et technique sur la gestion des barrages, which pointed out several safety shortcomings of existing dams. Many were either very old or had undergone significant function change without being subsequently re-evaluated. A report by the Commission stated that damage following the floods could have been limited if the design and operating standards of the dams had been more stringent. A Dam Safety Act was adopted by the Quebec National Assembly on May 30, 2000 following recommendations to retain safer structures. The Act demands regular reporting of operating procedures. Seismic activity was noted as being a topic that requires in-depth examination since Quebec's St. Lawrence Valley, particularly the Charlevoix region, is one of Canada's largest seismic zones. The other is on the west coast in British Columbia. Earthquakes in Quebec are less intense than the ones in British Columbia, but they have higher frequency content which exerts a quasi-resonance wave effect which impacts roads, bridges, buildings and hydroelectric generating facilities. Hydro-Quebec is a public utility which owns 563 retaining structures, of which 228 are ranked as large dams that measure more than 15 metres high, 400 metres long and with a reservoir capacity of more than 1 million cubic metres of water. Hydro-Quebec addresses hydrological, seismic, technological and human risks through a dam safety procedure that includes structured plans for choosing best alternatives through staged exercises. Hazard levels are minimized through the adoption of emergency, prevention and alleviation measures. The utility

  19. Assessing Risks of Mine Tailing Dam Failures

    Science.gov (United States)

    Concha Larrauri, P.; Lall, U.

    2017-12-01

    The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

  20. Research on Safety Factor of Dam Slope of High Embankment Dam under Seismic Condition

    Directory of Open Access Journals (Sweden)

    Li Bin

    2015-01-01

    Full Text Available With the constant development of construction technology of embankment dam, the constructed embankment dam becomes higher and higher, and the embankment dam with its height over 200m will always adopt the current design criteria of embankment dam only suitable for the construction of embankment dam lower than 200m in height. So the design criteria of high embankment dam shall be improved. We shall calculate the stability and safety factors of dam slope of high embankment dam under different dam height, slope ratio and different seismic intensity based on ratio of safety margin, and clarify the change rules of stability and safety factors of dam slope of high embankment dam with its height over 200m. We calculate the ratio of safety margin of traditional and reliable method by taking the stable, allowable and reliability index 4.2 of dam slope of high embankment dam with its height over 200m as the standard value, and conduct linear regression for both. As a result, the conditions, where 1.3 is considered as the stability and safety factors of dam slope of high embankment dam with its height over 200m under seismic condition and 4.2 as the allowable and reliability index, are under the same risk control level.

  1. Operational disease screening program for resistance to wilt in Acacia koa in Hawaii

    Science.gov (United States)

    Nick Dudley; Robert James; Richard Sniezko; Phil Cannon; Aileen Yeh; Tyler Jones; Michael Kaufmann

    2012-01-01

    In Hawaii, koa (Acacia koa A. Gray) is a valuable tree species economically, ecologically, and culturally. With significant land use change and declines in sugarcane, pineapple, and cattle production, there is an opportunity and keen interest in utilizing native koa in reforestation and restoration efforts. However, moderate to high mortality rates...

  2. Biomass and nutrient mass of Acacia dealbata and Eucalyptus globulus bioenergy plantations

    Science.gov (United States)

    Timothy J. Albaugh; Rafael A. Rubilar; Chris A. Maier; Eduardo A. Acuña; Rachel L. Cook

    2017-01-01

    We quantified biomass and nutrient accumulation of Acacia dealbata Link and Eucalyptus globulus Labill. planted at stem densities of 5000 and 15000 ha-1 in a bioenergy plantation in Chile. We tested the hypotheses that species and stocking will not affect biomass or nutrient accumulation. Species and...

  3. Early field performance of Acacia koa seedlings grown under subirrigation and overhead irrigation

    Science.gov (United States)

    Anthony S. Davis; Jeremiah R. Pinto; Douglass F. Jacobs

    2011-01-01

    Koa (Acacia koa A. Gray [Fabaceae]) seedlings were grown with subirrigation and overhead irrigation systems in an effort to characterize post-nursery field performance. One year following outplanting, we found no differences in seedling height or survival, but root-collar diameter was significantly larger for subirrigated seedlings. This indicates that koa seedlings,...

  4. Nursery response of Acacia koa seedlings to container size, irrigation method, and fertilization rate

    Science.gov (United States)

    R. Kasten Dumroese; Anthony S. Davis; Douglass F. Jacobs

    2011-01-01

    Planting koa (Acacia koa A. Gray) in Hawai'i, USA aids in restoration of disturbed sites essential to conservation of endemic species. Survival and growth of planted seedlings under vegetative competition typically increases with initial plant size. Increasing container size and fertilizer rate may produce larger seedlings, but high fertilization can lead to...

  5. A breeding strategy for Acacia mearnsii (black wattle) in South Africa ...

    African Journals Online (AJOL)

    A breeding strategy for Acacia mearnsii (black wattle) in South Africa: management paper. RW Dunlop, RD Barnes, KM Nixon, SF Hagedorn. Abstract. The black wattle breeding programme that has served the wattle bark industry of South Africa for the past five decades put little emphasis on improving the yield and quality ...

  6. In vivo and in vitro effect of Acacia nilotica seed proteinase inhibitors ...

    Indian Academy of Sciences (India)

    Acacia nilotica proteinase inhibitor (AnPI) was isolated by ammonium sulphate precipitation followed by chromatography on DEAE-Sephadex A-25 and resulted in a purification of 10.68-fold with a 19.5% yield. Electrophoretic analysis of purified AnPI protein resolved into a single band with molecular weight of ...

  7. Modeling relaxation length and density of acacia mangium wood using gamma - ray attenuation technique

    International Nuclear Information System (INIS)

    Tamer A Tabet; Fauziah Abdul Aziz

    2009-01-01

    Wood density measurement is related to the several factors that influence wood quality. In this paper, density, relaxation length and half-thickness value of eight ages, 3, 5, 7, 10, 11, 13 and 15 year-old of Acacia mangium wood were determined using gamma radiation from 137 Cs source. Results show that Acacia mangium tree of age 3 year has the highest relaxation length of 83.33 cm and least density of 0.43 gcm -3 , while the tree of age 15 year has the least Relaxation length of 28.56 cm and highest density of 0.76 gcm -3 . Results also show that the 3 year-old Acacia mangium wood has the highest half thickness value of 57.75 cm and 15 year-old tree has the least half thickness value of 19.85 cm. Two mathematical models have been developed for the prediction of density, variation with relaxation length and half-thickness value of different age of tree. A good agreement (greater than 85% in most cases) was observed between the measured values and predicted ones. Very good linear correlation was found between measured density and the age of tree (R2 = 0.824), and between estimated density and Acacia mangium tree age (R2 = 0.952). (Author)

  8. intra-species variation of the properties of gum exudates from acacia ...

    African Journals Online (AJOL)

    a

    . 1997, 11, 493. 22. Food Chemicals Codex III. Acacia (Gum arabic), National Academy of Sciences,. Washington D.C.; 1981, p 7. 23. Mhinzi, G.S.; Mosha, D.M.S. J. Chem. Soc. Pak. 1993, 15, 269. 24. Mhinzi, G.S.; Mosha, D.M.S. J.Food Sci.

  9. Early growth and survival of Acacia galpinii after planting in a semi ...

    African Journals Online (AJOL)

    Foliage transparency was in excess of 80% for all age groups while crown dieback and stem damage was below 5%. A. galpinii was found to be suitable for dry-zone afforestation. Key Words: Indigenous tree planting; Acacia galpinii; Growth rate; Survival rate; Tree health. Southern African Forestry Journal Issue 202 2004: ...

  10. Preparation and evaluation of pellets using acacia and tragacanth by extrusion-spheronization.

    Science.gov (United States)

    Akhgari, A; Abbaspour, M R; Pirmoradi, S

    2011-01-01

    Extrusion-spheronization is an established technique for the production of pellets for pharmaceutical applications. In this study, the feasibility and influence of the incorporation of acacia, by itself and in combination with tragacanth, on the ability of formulations containing 2 model of drugs (ibuprofen and theophylline) to form spherical pellets by extrusion-spheronization was investigated. Formulations containing different ratios of acacia and tragacanth (8:2, 9:1, and 10:0) and different drug concentrations (20%, 40%, and 60%) were prepared, on the basis of a 3(2) full factorial design. Pellet properties, such as aspect ratio, sphericity (image analysis), crushing strength and elastic modulus (mechanical tests), mean dissolution time, and dissolution profiles were evaluated. The effect of particular factors on responses was determined by linear regression analysis. The sphericity, drug release rate, and the mechanical properties of the pellets were affected by the amounts and types of the drugs, and the ratio of the gums. Acacia, relative to tragacanth, produced pellets with higher mechanical strength and a faster drug release rate. Addition of small amounts of tragacanth to ibuprofen formulations resulted in matrix pellets with slow drug release. The results showed that acacia and tragacanth can be used successfully as 2 natural binders in the pellet formulations.

  11. intra-species variation of the properties of gum exudates from acacia ...

    African Journals Online (AJOL)

    a

    senegal e.g. A senegal var. leiorhachis which may also find their way into commercial gum arabic shipments may have solution properties which vary significantly from the main species. This paper presents the intra-species variation of the properties of gum exudates from Acacia senegal var. senegal and A. seyal var. fistula ...

  12. An analysis of the African Acacia species: their distribution, possible origins and relationships

    Directory of Open Access Journals (Sweden)

    J. H. Ross

    1981-11-01

    Full Text Available The three subgenera recognized within the genus Acacia are outlined and the global distribution of each is indicated. The differences between the subgenera and the degree of relationship and levels of specialization are discussed briefly. It is suggested that the ancestral members of the genus were climbers or lianes. Past geological events considered likely to have influenced the distribution of the  Acacia species in Africa are outlined. The number of  species recorded from each African country is tabulated and the distribution and concentration of species within the genus Acacia as a whole and within each subgenus in Africa are illustrated. The highest concentrations of species within each subgenus occur in tropical east and south-east Africa. The distribution o f species within some o f the individual African countries and possible affinities are discussed and attention is drawn to the main centres of endemism. The distribution of the African species is correlated with the major phytogeographical regions recognized on the continent. The relationships between the African and the American, Madagascan, Indian and Australian  Acacia species are discussed briefly.

  13. Invasiveness in introduced Australian acacias: the role of species traits and geneome size

    Czech Academy of Sciences Publication Activity Database

    Gallagher, R. V.; Leishmann, M. R.; Miller, J. T.; Hui, C.; Richardson, D. M.; Suda, Jan; Trávníček, Pavel

    2011-01-01

    Roč. 17, č. 5 (2011), s. 884-897 ISSN 1366-9516 Institutional research plan: CEZ:AV0Z60050516 Keywords : Acacia * biological invasions * flow cytometry Subject RIV: EF - Botanics Impact factor: 4.830, year: 2011

  14. Effects of phosphorus fertilization, seed source, and soil type on growth of Acacia koa

    Science.gov (United States)

    P. G. Scowcroft; J. A. Silva

    2005-01-01

    The endemic tree Acacia koa is used to reforest abandoned agricuItural lands in Hawaii. Growth may be constrained by soil infertility and toxic concentrations of aluminum (AI) and manganese (Mn) in acidic Oxisols and Ultisols, The effects of phosphorus (P) fertilization at time of planting, soil type, and seed source on koa growth were studied for three years....

  15. The anti-viral effect of Acacia mellifera, Melia azedarach and Prunus ...

    African Journals Online (AJOL)

    Aqueous extracts from the stem barks of Prunus africana(Hook.f.) Kalkm, Acacia mellifera (Vahl.) Benth. and Melia azedarach L. were evaluated for in vivo antiviral activity in Balb/C mice following a cutaneous wild type strain 7401H herpes simplex virus type 1 (HSV-1) infection. A significant therapeutic effect was observed ...

  16. Aboveground biomass equations for 7-year-old Acacia mangium Willd in Botucatu, Brazil

    Science.gov (United States)

    Ricardo A. A. Veiga; Maria A. M. Brasil; Carlos M. Carvalho

    2000-01-01

    The biomass of steins, leaves, and branches was determined for 152 sample trees of Acacia mangium Willd were in a 7-year-old experimental plantation in Botucatu, Sao Paulo State, Brazil. After felling, dimensional measurements were taken from each tree. Cross sections were collected in 125 sample trees at ground level (0 percent), 25 percent, 50...

  17. In vitro biological activity of tannins from Acacia and other tree fruits ...

    African Journals Online (AJOL)

    This study was designed to investigate impact of tannins on in vitro ruminal fermentation parameters as well as relationships between concentration and in vitro biological activity of tannins present in tree fruits. Dry and mature fruits of known phenolic content harvested from Acacia nilotica, A. erubescens, A. erioloba, ...

  18. Acacia saligna: an invasive species on the coast of Molise (southern Italy

    Directory of Open Access Journals (Sweden)

    Calabrese V

    2017-02-01

    Full Text Available Italy is one of the European countries most affected by biological invasions. In this study, we focused on the impact of Acacia saligna, an Australian invasive plant species, on the coastal ecosystem’s ecology and biodiversity along the sandy coasts of Molise (southern Italy. We analyzed data from 61 vegetation plots recorded in coastal pine forest and Mediterranean scrub habitats of Molise throughout the preparatory actions of the “LIFE Maestrale” project (NAT/IT/000262. In order to study the ecological impact of Acacia saligna comparing invaded and non-invaded areas, we first assigned the Ellenberg’s indicator values to each plant species, which were then used to relate the presence of Acacia saligna with ecological characteristics of sites through a generalized linear model (GLM. Our results showed a significant positive relationship between the presence of Acacia saligna and high levels of soil nutrients and, on the contrary, a negative relationship with the presence of mesophilic species, which are typical of the community interest habitats of pine forest (2270*. The use of ecological indicators is effective to pinpoint the ecological effects of biological invasions, as well as to evaluate habitat conservation state and to identify vulnerable native species.

  19. Antioxidant capacities of extracts in relation to toasting oak and acacia wood

    Czech Academy of Sciences Publication Activity Database

    Híc, P.; Soural, I.; Balík, J.; Kulichová, J.; Vrchotová, Naděžda; Tříska, Jan

    2017-01-01

    Roč. 56, č. 2 (2017), s. 129-137 ISSN 1336-8672 Institutional support: RVO:67179843 Keywords : oak * acacia * toasting wood * barrique extract * antioxidant capacity * weight loss Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 1.950, year: 2016

  20. Stable isotope ratios and reforestation potential in Acacia koa populations on Hawai'i

    Science.gov (United States)

    Shaneka Lawson; Carrie Pike

    2017-01-01

    Stable carbon and nitrogen isotopes can be influenced by a multitude of factors including elevation, precipitation rate, season, and temperature. This work examined variability in foliar stable carbon (δ13C) and nitrogen (δ15N) isotope ratios of koa (Acacia koa) across 17 sites on Hawai'i Island, delineated by elevation and precipitation...

  1. Pollination ecology of Acacia gerrardii Benth. (Fabaceae: Mimosoideae under extremely hot-dry conditions

    Directory of Open Access Journals (Sweden)

    Abdulaziz Saad Alqarni

    2017-11-01

    Full Text Available Talh trees (Acacia gerrardii Benth. are acacias that are native to the arid and semiarid Africa and west Asia. We investigated the flowering biology, pod set and flower visitors of Talh and discussed the role of these visitors in pollen transfer. The Talh trees blossomed laterally on the nodes of one-year-old twigs. Each node produced 21 flower buds seasonally. Each flower bud opened to a flower head (FH of 60 florets. The bagged FHs podded significantly (p ⩽ 0.05 less than did the unbagged FHs. The FHs were visited by 31 insect species (25 genera, 16 families and 5 orders. The major taxa were honeybees, megachilids, butterflies, ants, beetles and thrips. Each of honeybees, megachilids and beetles showed a significant (p ⩽ 0.05 hourly pattern, while each of butterflies, ants and thrips had no hourly pattern (p > 0.05. Furthermore, some birds and mammals touched the Talh FHs. Talh trees evolved a mass flowering behavior to face pre- and post-flowering obstacles. Megachilids seemed to play the major effort of zoophily because of their relatively high numbers of individuals and species and their effective movement behavior on the FH surface. Nevertheless, honeybees and other insects and vertebrate taxa also contributed to the pollen transfer. These results greatly contribute to our understanding of the pollination ecology of acacias, especially Arabian acacias.

  2. STRATEGI DIVERSIFIKASI PRODUK KAYU OLAHAN Acacia mangium (studi kasus : PT. Musi Hutan Persada

    Directory of Open Access Journals (Sweden)

    Hamzah Hamzah

    2011-08-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 The objective of this study is to suggest  the best wood  products of Acacia mangium  that have  high value-added as an alternative business and to formulate the fitting  strategy. This study  is descriptive case study applying  purposive sampling method which involved wood product Experts and Senior PT. Musi Hutan Persada Management.  Data have been analyzed through Exponential Compare Method (MPE to select the best product alternative based on eleven set criteria, using AHP method, Hayami value-added Analysis, and Cost Analysis.  The study shows that there are five superior Acacia mangium based products, namely 1 Sawnwood and woodworking (KGKO, 2 Furniture, 3 Medium Density Fibreboard (MDF, 4 Tannin-glue of Acacia mangium  bark and 5 Wood Charcoal.  And  Sawnwood and Woodworking (KGKO, Furniture, and   Tannin-glue  have the best chance.  Best business strategy to be adhered by MHP, “related-diversification”, then is  to continue utilizing  Acacia mangium wood  as renewable resources,  integrated and sustainable business.

  3. Coexistence and performance of diploid and polyploid Acacia senegal (L.) Willd

    DEFF Research Database (Denmark)

    Diallo, Adja Madjiguene

    Polyploidy is defined as possession of more than two sets of chromosomes of an organism. It is known to play a major role in evolution of organisms, but few studies are available on Sahelian trees. In the case of Acacia senegal (distributed across the Sahel), it is important to clarify the potent...

  4. Effect of Aqueous Extract of Acacia nilotica on Microbial and Castor ...

    African Journals Online (AJOL)

    Prof. Ogunji

    bone marrow in iron utilization, anaemia, leucopenia, unpleasant mouth taste, nausea, vomiting ..... Biology of Acacias. Oxford. University Press. Melbourne. Pp153. Okoro, S.O, Kawo, A. H, and Arzai, A. H.. (2004). Phytochemical Screening, anti-bacteria and Toxicology activities of A. nilotica extracts. Bayero Journal of Pure ...

  5. Preparation and Evaluation of Pellets Using Acacia and Tragacanth by Extrusion-Spheronization

    Directory of Open Access Journals (Sweden)

    S. Pirmoradi

    2011-12-01

    Full Text Available Background and the purpose of the study: Extrusion-spheronization is an established technique for the production of pellets for pharmaceutical applications. In this study, the feasibility and influence of the incorporation of acacia, by itself and in combination with tragacanth, on the ability of formulations containing 2 model of drugs (ibuprofen and theophylline to form spherical pellets by extrusion-spheronization was investigated.Material and Methods: Formulations containing different ratios of acacia and tragacanth (8:2, 9:1, and 10:0 and different drug concentrations (20%, 40%, and 60% were prepared, on the basis of a 32 full factorial design. Pellet properties, such as aspect ratio, sphericity (image analysis, crushing strength and elastic modulus (mechanical tests, mean dissolution time, and dissolution profiles were evaluated. The effect of particular factors on responses was determined by linear regression analysis.Results: The sphericity, drug release rate, and the mechanical properties of the pellets were affected by the amounts and types of the drugs, and the ratio of the gums. Acacia, relative to tragacanth, produced pellets with higher mechanical strength and a faster drug release rate. Addition of small amounts of tragacanth to ibuprofen formulations resulted in matrix pellets with slow drug release.Conclusion: The results showed that acacia and tragacanth can be used successfully as 2 natural binders in the pellet formulations.

  6. Remotely installed steam generator nozzle dam system

    International Nuclear Information System (INIS)

    Mc Donald, F.X.; Weisel, E.M.; Schukei, G.E.

    1990-01-01

    This patent describes a method for remotely installing a dam unit in a nozzle or a nuclear steam generator head, the head including a manway. It comprises: mounting an articulated manipulator to an internal surface of the head, the manipulator having a free end which carries a jaw member; positioning the manipulator so that the jaw member is adjacent the manway and substantially on the manway axis; passing a first dam segment through the manway and attaching the jaw member to the first segment; positioning the manipulator so that the jaw member holds the first dam segment on one side of the manway axis; passing a second dam segment through the manway into engagement with the first dam segment to form a dam subassembly; translating the manipulator through the head until the dam subassembly is adjacent the nozzle; advancing the jaw member toward the nozzle until the cam subassembly is positioned substantially at the desired location of the dam unit with respect to the nozzle; and deploying the manipulator to install dam support structure between the dam subassembly and the steam generator, thereby forming an installed dam unit

  7. PRODUCTION OF MANGIUM (Acacia mangium WOOD VINEGAR AND ITS UTILIZATION

    Directory of Open Access Journals (Sweden)

    Tjutju Nurhayati

    2005-03-01

    Full Text Available Production  of  wood vinegar from mangium (Acacia  mangium wood bolts/pieces  with their diameter of 3  17 cm, length of 30  67 cm, moisture content of 84.4%, and specific gravity of 0.52 conducted in a dome-shaped kiln with 1.2 m'-capacity afforded a yield of 40.3%.   The mangium wood vinegar was produced  through condensation  (cooling of  smoke/gas fractions released during the charcoaling (carbonization process  of  mangium wood.    The  process  could be regarded  as an integrated production of wood vinegar and charcoal.  The yield of wood vinegar combined with the resulting charcoal was 73.9%  based on  the dry weight of  inputed  mangium wood.    Results of chromatography analysis on mangium wood vinegar as conducted in Japan revealed its organic acid content at 73.9 ppm, phenol content 8.09 ppm, methanol 3.34 ppm, acidity degree 4.91  ppm, and pH 3.89.   Similar analysis on the mangium wood vinegar was conducted in Indonesia's laboratories, and the results were comparable with  those  of  Japan.     Results of  inhibition  testings  on  particular microorganisms   (i.e.  Pseudomonas  aerogjnosa,  Stafi/ococms   attreus,  and  Candidi   albicans  fimgz indicated that the mangium wood vinegar could inflict antirnicrobe action on those microorganism with its effectiveness somewhat below that of  liquid betel soap which could be purchased  from drugstores.  The experimental use of mangium wood vinegar at 3-5% concentration on ginger (Zingiber officinale var. white ginger plants revealed significantly positive growth responses/  characteristics with respect to their height, leaf length, and sprout/ shoot development, in comparison with the untreated ginger plants (control.   Such responses/characteristics were not significantly different from those using atonik's growth hormone.  Likewise, the preliminary use of mangium wood vinegar at 2-percent concentration on teak

  8. Some thoughts on dam safety assessment: Small dams with not-so-small reservoirs

    International Nuclear Information System (INIS)

    Helwig, P.C.; Smith, W.L.

    1993-01-01

    There are about 300 dams in Newfoundland and Labrador of which only 9 are higher than 30 m. A significant number of these dams are less than 3 m in height yet retain appreciable volumes of water. Approaches to safety evaluations of these small dams vary considerably. Some authorities exclude such dams from mandatory inspections altogether, while others apply provisions that were clearly designed for more important structures. Neither approach is wholly satisfactory. Drawing on experience from inspection of over 100 mainly small dams, the issue is discussed and approaches to improve methods for dams safety evaluation of very small dams are suggested. Selection of design flood criteria, design guidelines, and reservoir flood standards are discussed. Newfoundland Power's dam safety assessment procedures for such dams are described. 8 refs., 2 figs., 3 tabs

  9. Study of Dam-break Due to Overtopping of Four Small Dams in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Zakaraya Alhasan

    2015-01-01

    Full Text Available Dam-break due to overtopping is one of the most common types of embankment dam failures. During the floods in August 2002 in the Czech Republic, several small dams collapsed due to overtopping. In this paper, an analysis of the dam break process at the Luh, Velký Bělčický, Melín, and Metelský dams breached during the 2002 flood is presented. Comprehensive identification and analysis of the dam shape, properties of dam material and failure scenarios were carried out after the flood event to assemble data for the calibration of a numerical dam break model. A simple one-dimensional mathematical model was proposed for use in dam breach simulation, and a computer code was compiled. The model was calibrated using the field data mentioned above. Comparison of the erodibility parameters gained from the model showed reasonable agreement with the results of other authors.

  10. STUDI PRODUKTIVITAS DAN RENDEMEN INDUSTRI PENGGERGAJIAN KAYU AKASIA DAUN LEBAR (Acacia mangium Willd DI KECAMATAN LANDASAN ULIN KOTA BANJARBARU KALIMANTAN SELATAN

    Directory of Open Access Journals (Sweden)

    Rosidah R Radam

    2016-08-01

    Full Text Available The activity of sawmill have been long enough done by local society because very assistive and add production socialize, some of owner of bandsaw/sawmill also make this effort as effort remain to and there is also making it as effort peripheral.  Intention of this research is to know industrial and rendemen productivity of sawmill of acacia wide leaf wood (Acacia mangium Willd.  The method that being used is method of direct measurement and observation in industrial location of sawmill of acacia wide leaf wood and method of direct interview and also record data that related to this research.  The analyse data is productivity calculation, rendemen and waste.  Productivity mean of industrial sawmill of acacia wide leaf wood is equal to 6,38 m3/day or 0,0160 m3/hours. Rendemen mean of industrial sawmill of acacia wide leaf wood is equal to 80,011%.  Mean of industrial disposal of sawmill of acacia wide leaf wood is equal to 19,99% (1,62 m3, this matter is caused by a quality wood of good Acacia (not many experiencing of handicap of wood.  From result of research suggested to conduct research of continuation hit influence of other factor to productivity and rendemen at acacia wide leaf wood sawmill like age, environmental work (arrange situation, and the worker education. Keyords :  productivity, rendemen, waste, sawmill, acacia wide leaf wood (Acacia mangium Willd

  11. Crotch Lake dam rehabilitation project

    International Nuclear Information System (INIS)

    Brunet, G.; Dobrowolski, E.

    1999-01-01

    Replacement of the existing wood crib dam structure on Crotch Lake on the Mississippi River in eastern Ontario that provided water storage for the power production at High Falls Generating Station, became necessary when it was determined that the dam did not meet Ontario-Hydro's safety standards. This paper describes the project of replacing the existing structure with a PVC coated gabion wall with waterproofing. The entire structure was covered with three layers of wire mesh, laced together, and criss-crossed for superior strength and rigidity. The work was completed in 28 days with no environmental impact . Life expectancy of the new structure is in excess of 40 years. With periodic maintenance of the gabion mat cover, life span could be extended an additional 20 to 40 years. 5 figs

  12. Seismic Analysis of Gravity Dams.

    Science.gov (United States)

    method of analysis with the results produced by the well-known program EADHI. A new simplified method of analysis was developed using the finite element method of analysis to determine the dam’s inertial response along with Chopra’s simplified procedure for estimating the hydrodynamic loading. This new approach was implemented in a user-friendly computer program. The program was tested against a wide variety of problems and found to produce acceptable results. A sample run using this

  13. Environmental monitoring at Olympic Dam

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    The environmental management and protection program at the Olympic Dam uranium/copper/gold project, Roxby Downs, South Australia, monitors eight major environmental parameters - meteorology, vegetation, mine site rehabilitation, fauna, terrain, soil salinity, hydrogeology and well fields. It came into effect with the approval of the South Australian Government in March 1987. The Great Artesian Basin, one of the world's greatest artesian basins, is the source of the water supply for the project

  14. Mitigating Dam Impacts Using Environmental Flow Releases

    Science.gov (United States)

    Richter, B. D.

    2017-12-01

    One of the most ecologically disruptive impacts of dams is their alteration of natural river flow variability. Opportunities exist for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. This presentation will highlight a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the suggested strategies for dam re-operation are predicated on changes in the end-use of the water, such as reductions in urban or agricultural water use during droughts, a systemic perspective of entire water management systems will be required to attain the fullest possible

  15. Supplementing lactating dairy cows fed high-quality pasture with black wattle (Acacia mearnsii) tannin.

    Science.gov (United States)

    Griffiths, W M; Clark, C E F; Clark, D A; Waghorn, G C

    2013-11-01

    A reduction in urinary nitrogen (N) excretion from dairy cows fed pasture containing a high N concentration in the dry matter (DM) will have environmental benefits, because losses to soil water and air by leachate and nitrous oxides (N2O) will be reduced. Condensed tannins (CT) reduce digestion of N, and provision as a dietary additive could have nutritional benefits for production, but the amount required and the responses to different sources of CT on milk production have not been defined. Two experiments were conducted to evaluate effects of supplementation with CT extracted from black wattle (Acacia mearnsii De Wild.) on milk production and faecal N concentration by lactating dairy cows grazing a vegetative Perennial ryegrass (Lolium perenne L.)-based pasture. In one experiment, CT was administered as a drench, twice daily, to 38 multiparous Holstein-Friesian cows assigned to four treatments; control (CONT, 0 g/day), low CT (LCT, 111 g/day), medium CT (MCT, 222 g/day) and high CT (HCT, 444 g/day), grazing as a single group. The CT supplementation affected milk yield (P milk yield as CT concentration increased from about 0.6 to about 2.9% of dietary DM. Milk urea nitrogen (MUN) decreased at MCT and HCT levels of supplementation (P milk fat, CP and lactose percentage were not affected by CT supplementation. The CT supplementation increased N concentration in faeces for LCT and MCT treatments (P milking, it reduced the acceptability relative to pellets without CT, and tended to lower milk production from 25.4 to 24.5 kg/day, although the decline was not significant (P > 0.05). The diet of cows fed pellets with CT contained about 1.2% CT in the DM but neither milk constituents nor MUN were affected by CT-supplemented grain (P > 0.05). These findings demonstrate beneficial effects for production of low concentrations (c. 0.6% DM) of CT from black wattle when given to cows grazing pasture with an N concentration of 3.8%, and suggest a diversion of N from urine, but

  16. Acacia cyclops A. Cunn. ex G. Don (Leguminosae in Italy: first cases of naturalization

    Directory of Open Access Journals (Sweden)

    Pasta, Salvatore

    2012-12-01

    Full Text Available The first two cases of naturalization of Acacia cyclops are reported for Italy. Young trees were observed growing in the wild some 15 years ago on Linosa (Pelagie Islands, Strait of Sicily. A decade later, this alien plant should no longer be considered as a casual, since a very intensive process of self-sown regeneration has been observed in some plantations on Lampedusa, the major island of the same Archipelago. The available literature suggests the need for careful monitoring of the ongoing invasion process, as A. cyclops has already shown a very invasive behaviour elsewhere within Mediterranean-type biomes due to its ability to withstand high environmental stresses. As migrating birds are suspected to have played an important role in facilitating the arrival of A. cyclops, further propagules are likely to reach the islands in the future. We recommend that new plantations of A. cyclops should be forbidden, but that extant naturalized populations should be managed instead of eradicating them. In fact, the effect of Acacia plantations warrants investigation at different scales in order to assess their impact on local plant-diversity and ecological succession processes.

    Se muestran los dos primeros casos de naturalización de Acacia cyclops para el territorio italiano. Se observó que las plántulas de este arbol crecen en forma silvestre hace unos 15 años en Linosa (islas Pelagias, estrecho de Sicilia. Una década después, ya no puede ser considerada una xenófita casual ya que se observó una regeneración muy intensa en algunos proyectos de reforestación en Lampedusa, la isla más grande del mismo archipiélago. Publicaciones anteriores sugieren la necesidad de un monitoreo cuidadoso del proceso de invasión en curso, ya que A. cyclops ha expresado un comportamiento altamente invasivo en otros biomas de tipo mediterráneo, debido a su alta tolerancia al estrés ambiental. Dado que se

  17. Exporting dams: China's hydropower industry goes global.

    Science.gov (United States)

    McDonald, Kristen; Bosshard, Peter; Brewer, Nicole

    2009-07-01

    In line with China's "going out" strategy, China's dam industry has in recent years significantly expanded its involvement in overseas markets. The Chinese Export-Import Bank and other Chinese financial institutions, state-owned enterprises, and private firms are now involved in at least 93 major dam projects overseas. The Chinese government sees the new global role played by China's dam industry as a "win-win" situation for China and host countries involved. But evidence from project sites such as the Merowe Dam in Sudan demonstrates that these dams have unrecognized social and environmental costs for host communities. Chinese dam builders have yet to adopt internationally accepted social and environmental standards for large infrastructure development that can assure these costs are adequately taken into account. But the Chinese government is becoming increasingly aware of the challenge and the necessity of promoting environmentally and socially sound investments overseas.

  18. Automated data acquisition for dam monitoring

    International Nuclear Information System (INIS)

    Koopmans, R.; Jakubick, A.T.

    1990-01-01

    Automated data acquisition for dam monitoring is crucial to emergency response, allows frequent readings without increased labour and cost, allows monitoring of instrument response to changing environmental and physical influences, enables direct computer acquisition of data, and has numerous other advantages. The experience of Ontario Hydro, British Columbia Hydro, and other utilities with automated data acquisition systems is described. Details are provided of remote monitoring systems, instrumentation, data loggers, tape cassette backup, power sources, data transmission equipment, modems and telephone networks, computers and peripherals, and system performance. The utility's plans for future expansion of the systems are described. Utility experience with the automated systems is also described for Clarence Dam, Bath County Pumped Storage Station, Scott Dam, and Vermillion Dam in the U.S., Ajaure Dam in Sweden, and ENEL Dam in the Valtellina area of Italy. 17 refs., 2 figs

  19. Measurement of Dam Deformations: Case Study of Obruk Dam (Turkey)

    Science.gov (United States)

    Gulal, V. Engin; Alkan, R. Metin; Alkan, M. Nurullah; İlci, Veli; Ozulu, I. Murat; Tombus, F. Engin; Kose, Zafer; Aladogan, Kayhan; Sahin, Murat; Yavasoglu, Hakan; Oku, Guldane

    2016-04-01

    In the literature, there is information regarding the first deformation and displacement measurements in dams that were conducted in 1920s Switzerland. Todays, deformation measurements in the dams have gained very different functions with improvements in both measurement equipment and evaluation of measurements. Deformation measurements and analysis are among the main topics studied by scientists who take interest in the engineering measurement sciences. The Working group of Deformation Measurements and Analysis, which was established under the International Federation of Surveyors (FIG), carries out its studies and activities with regard to this subject. At the end of the 1970s, the subject of the determination of fixed points in the deformation monitoring network was one of the main subjects extensively studied. Many theories arose from this inquiry, as different institutes came to differing conclusions. In 1978, a special commission with representatives of universities has been established within the FIG 6.1 working group; this commission worked on the issue of determining a general approach to geometric deformation analysis. The results gleaned from the commission were discussed at symposiums organized by the FIG. In accordance with these studies, scientists interested in the subject have begun to work on models that investigate cause and effect relations between the effects that cause deformation and deformation. As of the scientist who interest with the issue focused on different deformation methods, another special commission was established within the FIG engineering measurements commission in order to classify deformation models and study terminology. After studying this material for a long time, the official commission report was published in 2001. In this prepared report, studies have been carried out by considering the FIG Engineering Surveying Commission's report entitled, 'MODELS AND TERMINOLOGY FOR THE ANALYSIS OF GEODETIC MONITORING OBSERVATIONS

  20. Impacts of Dams and Global Warming on Fish Biodiversity in the Indo-Burma Hotspot.

    Science.gov (United States)

    Kano, Yuichi; Dudgeon, David; Nam, So; Samejima, Hiromitsu; Watanabe, Katsutoshi; Grudpan, Chaiwut; Grudpan, Jarungjit; Magtoon, Wichan; Musikasinthorn, Prachya; Nguyen, Phuong Thanh; Praxaysonbath, Bounthob; Sato, Tomoyuki; Shibukawa, Koichi; Shimatani, Yukihiro; Suvarnaraksha, Apinun; Tanaka, Wataru; Thach, Phanara; Tran, Dac Dinh; Yamashita, Tomomi; Utsugi, Kenzo

    2016-01-01

    Both hydropower dams and global warming pose threats to freshwater fish diversity. While the extent of global warming may be reduced by a shift towards energy generation by large dams in order to reduce fossil-fuel use, such dams profoundly modify riverine habitats. Furthermore, the threats posed by dams and global warming will interact: for example, dams constrain range adjustments by fishes that might compensate for warming temperatures. Evaluation of their combined or synergistic effects is thus essential for adequate assessment of the consequences of planned water-resource developments. We made projections of the responses of 363 fish species within the Indo-Burma global biodiversity hotspot to the separate and joint impacts of dams and global warming. The hotspot encompasses the Lower Mekong Basin, which is the world's largest freshwater capture fishery. Projections for 81 dam-building scenarios revealed progressive impacts upon projected species richness, habitable area, and the proportion of threatened species as generating capacity increased. Projections from 126 global-warming scenarios included a rise in species richness, a reduction in habitable area, and an increase in the proportion of threatened species; however, there was substantial variation in the extent of these changes among warming projections. Projections from scenarios that combined the effects of dams and global warming were derived either by simply adding the two threats, or by combining them in a synergistic manner that took account of the likelihood that habitat shifts under global warming would be constrained by river fragmentation. Impacts on fish diversity under the synergistic projections were 10-20% higher than those attributable to additive scenarios, and were exacerbated as generating capacity increased-particularly if CO2 emissions remained high. The impacts of dams, especially those on river mainstreams, are likely to be greater, more predictable and more immediately pressing for

  1. Impacts of Dams and Global Warming on Fish Biodiversity in the Indo-Burma Hotspot.

    Directory of Open Access Journals (Sweden)

    Yuichi Kano

    Full Text Available Both hydropower dams and global warming pose threats to freshwater fish diversity. While the extent of global warming may be reduced by a shift towards energy generation by large dams in order to reduce fossil-fuel use, such dams profoundly modify riverine habitats. Furthermore, the threats posed by dams and global warming will interact: for example, dams constrain range adjustments by fishes that might compensate for warming temperatures. Evaluation of their combined or synergistic effects is thus essential for adequate assessment of the consequences of planned water-resource developments. We made projections of the responses of 363 fish species within the Indo-Burma global biodiversity hotspot to the separate and joint impacts of dams and global warming. The hotspot encompasses the Lower Mekong Basin, which is the world's largest freshwater capture fishery. Projections for 81 dam-building scenarios revealed progressive impacts upon projected species richness, habitable area, and the proportion of threatened species as generating capacity increased. Projections from 126 global-warming scenarios included a rise in species richness, a reduction in habitable area, and an increase in the proportion of threatened species; however, there was substantial variation in the extent of these changes among warming projections. Projections from scenarios that combined the effects of dams and global warming were derived either by simply adding the two threats, or by combining them in a synergistic manner that took account of the likelihood that habitat shifts under global warming would be constrained by river fragmentation. Impacts on fish diversity under the synergistic projections were 10-20% higher than those attributable to additive scenarios, and were exacerbated as generating capacity increased-particularly if CO2 emissions remained high. The impacts of dams, especially those on river mainstreams, are likely to be greater, more predictable and more

  2. Impacts of Dams and Global Warming on Fish Biodiversity in the Indo-Burma Hotspot

    Science.gov (United States)

    Nam, So; Samejima, Hiromitsu; Watanabe, Katsutoshi; Grudpan, Chaiwut; Grudpan, Jarungjit; Magtoon, Wichan; Musikasinthorn, Prachya; Nguyen, Phuong Thanh; Praxaysonbath, Bounthob; Sato, Tomoyuki; Shimatani, Yukihiro; Suvarnaraksha, Apinun; Tanaka, Wataru; Thach, Phanara; Tran, Dac Dinh; Yamashita, Tomomi

    2016-01-01

    Both hydropower dams and global warming pose threats to freshwater fish diversity. While the extent of global warming may be reduced by a shift towards energy generation by large dams in order to reduce fossil-fuel use, such dams profoundly modify riverine habitats. Furthermore, the threats posed by dams and global warming will interact: for example, dams constrain range adjustments by fishes that might compensate for warming temperatures. Evaluation of their combined or synergistic effects is thus essential for adequate assessment of the consequences of planned water-resource developments. We made projections of the responses of 363 fish species within the Indo-Burma global biodiversity hotspot to the separate and joint impacts of dams and global warming. The hotspot encompasses the Lower Mekong Basin, which is the world’s largest freshwater capture fishery. Projections for 81 dam-building scenarios revealed progressive impacts upon projected species richness, habitable area, and the proportion of threatened species as generating capacity increased. Projections from 126 global-warming scenarios included a rise in species richness, a reduction in habitable area, and an increase in the proportion of threatened species; however, there was substantial variation in the extent of these changes among warming projections. Projections from scenarios that combined the effects of dams and global warming were derived either by simply adding the two threats, or by combining them in a synergistic manner that took account of the likelihood that habitat shifts under global warming would be constrained by river fragmentation. Impacts on fish diversity under the synergistic projections were 10–20% higher than those attributable to additive scenarios, and were exacerbated as generating capacity increased—particularly if CO2 emissions remained high. The impacts of dams, especially those on river mainstreams, are likely to be greater, more predictable and more immediately

  3. Three Dimensional Seepage Analyses in Mollasadra Dam after Its ...

    African Journals Online (AJOL)

    Mollasadra dam is an earth fill dam with a clayey core and a height of 72 m from river bed, constructed on Kor River. pore water pressure in the dam was investigated following its construction and first and second impoundments. The dam was modeled by a finite element mesh. After the first and second dam impoundments, ...

  4. Global Reservoir and Dam Database, Version 1 (GRanDv1): Dams, Revision 01

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Reservoir and Dam Database, Version 1 (Revision 01) contains 6,862 records of reservoirs and their associated dams with a cumulative storage capacity of...

  5. Global Reservoir and Dam Database, Version 1 (GRanDv1): Dams, Revision 01

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Reservoir and Dam Database, Version 1, Revision 01 (v1.01) contains 6,862 records of reservoirs and their associated dams with a cumulative storage...

  6. Effects of biotic and abiotic constraints on the symbiosis between rhizobia and the tropical leguminous trees Acacia and Prosopis.

    Science.gov (United States)

    Räsänen, Leena A; Lindström, Kristina

    2003-10-01

    N2-fixing, drought tolerant and multipurpose Acacia and Prosopis species are appropriate trees for reforestation of degraded areas in arid and semiarid regions of the tropics and subtropics. Acacia and Prosopis trees form N2-fixing nodules with a wide range of rhizobia, for example African acacias mainly with Sinorhizobium sp. and Mesorhizobium sp., and Australian acacias with Bradyrhizobium sp. Although dry and hot seasons restrict formation of N2-fixing nodules on Acacia and Prosopis spp., fully grown trees and their symbiotic partners are well adapted to survive in harsh growth conditions. This review on one hand deals with major constraints of arid and semiarid soils, i.e. drought, salinity and high soil temperature, which affect growth of trees and rhizobia, and on the other hand with adaptation mechanisms by which both organisms survive through unfavourable periods. In addition, defects in infection and nodulation processes due to various abiotic and biotic constraints are reviewed. This knowledge is important when Acacia and Prosopis seedlings are used for forestation of degraded areas in arid and semiarid tropics.

  7. Studies of water leakage in dams. Course

    International Nuclear Information System (INIS)

    Cordero-Calderon, C.F.

    1995-01-01

    With this training about the study of Water Leakage in Dams and Damming, the institutional worker will have the necessary criteria in this topic, and also an opportunity to analyze the impact of this engineering work at national level. This course permits to transmit part of the knowlege acquired by the Arcal XVIII RLA/8/018, Application of Tracer Techniques for Leakage in Dams and Damming Project, where ICE participates in agreement with Atomic Energy Commission of Costa Rica, sponsored by the International Organization of Atomic Energy. (author). 14 charts, 36 figs, 2 maps, 6 tabs

  8. Dam safety management in Victoria (Australia)

    International Nuclear Information System (INIS)

    Adem, J.

    1996-01-01

    The Victoria state government's decision to make dam owners accountable for safety and upkeep of their dams was reported. To give effect to this decision a series of guidelines have been developed which outline the required activities and skills to ensure that dams are properly managed within a framework of 'light-handed' regulation. The guidelines are also intended to ensure that dam management becomes an integral part of the business decision making process, not just a set of prescribed technical procedures. Details of the direction being taken and the proposed controls to ensure compliance with national and international standards were described. 4 refs., 2 figs

  9. Risk assessment of a hydraulic fill dam

    International Nuclear Information System (INIS)

    Cattanach, J. D.; Stewart, R. A.

    1996-01-01

    The concerns expressed about the safety of the 85 year old 29 m hydraulic Coquitlam Dam in the Greater Vancouver area were described. Because of these concerns, and despite the fact that the dam meets the Incremental Hazard Classification criteria, B.C. Hydro carried out an evaluation with risk assessment. The processes employed and the results of the evaluation were described. It was found that although the dam was safe enough, in light of experiences with other dams, further evaluations will have to be carried out to verify these results. 2 refs., 6 figs

  10. Identification of lignin genes and regulatory sequences involved in secondary cell wall formation in Acacia auriculiformis and Acacia mangium via de novo transcriptome sequencing

    Directory of Open Access Journals (Sweden)

    Cannon Charles H

    2011-07-01

    Full Text Available Abstract Background Acacia auriculiformis × Acacia mangium hybrids are commercially important trees for the timber and pulp industry in Southeast Asia. Increasing pulp yield while reducing pulping costs are major objectives of tree breeding programs. The general monolignol biosynthesis and secondary cell wall formation pathways are well-characterized but genes in these pathways are poorly characterized in Acacia hybrids. RNA-seq on short-read platforms is a rapid approach for obtaining comprehensive transcriptomic data and to discover informative sequence variants. Results We sequenced transcriptomes of A. auriculiformis and A. mangium from non-normalized cDNA libraries synthesized from pooled young stem and inner bark tissues using paired-end libraries and a single lane of an Illumina GAII machine. De novo assembly produced a total of 42,217 and 35,759 contigs with an average length of 496 bp and 498 bp for A. auriculiformis and A. mangium respectively. The assemblies of A. auriculiformis and A. mangium had a total length of 21,022,649 bp and 17,838,260 bp, respectively, with the largest contig 15,262 bp long. We detected all ten monolignol biosynthetic genes using Blastx and further analysis revealed 18 lignin isoforms for each species. We also identified five contigs homologous to R2R3-MYB proteins in other plant species that are involved in transcriptional regulation of secondary cell wall formation and lignin deposition. We searched the contigs against public microRNA database and predicted the stem-loop structures of six highly conserved microRNA families (miR319, miR396, miR160, miR172, miR162 and miR168 and one legume-specific family (miR2086. Three microRNA target genes were predicted to be involved in wood formation and flavonoid biosynthesis. By using the assemblies as a reference, we discovered 16,648 and 9,335 high quality putative Single Nucleotide Polymorphisms (SNPs in the transcriptomes of A. auriculiformis and A. mangium

  11. A ravenous river reclaims its true course: the tale of Marmot Dam''s demise

    Science.gov (United States)

    Noreen Parks; Gordon Grant

    2009-01-01

    Removing dams that are outdated, unsafe, or pose significant economic or environmental costs has emerged in the last 10 years as a major river restoration strategy. The removal of the 45-foot-high Marmot Dam on the Sandy River in 2007 resulted in the biggest sediment release accompanying any dam removal to date. It also provided an unprecedented opportunity...

  12. Olympic Dam - the first decade

    International Nuclear Information System (INIS)

    Newton, A.W.; Wilson, M.A.; Harris, J.

    1988-01-01

    Most aspects of the pre-production phase of the Olympic Dam Project, from commencement of exploration in May 1975 through to commitment to development in December 1985 are documented here. The discovery by Western Mining Corporation Ltd of copper mineralisation on Roxby Downs Station in July 1975 has led to one of the more intensive base-metal exploration programmes undertaken in Australia. Comprehensive exploration, evaluation and feasibility studies between 1975 and 1985 have delineated a probable 450 million tonnes of higher grade ore containing 2.5% copper, 0.8 kg/t uranium oxide, 0.6 g/t gold and 6.0 g/t silver. The total resource is estimated at 2 billion tonnes containing 1.6% copper, 0.6 kg/t uranium oxide, 0.6 g/t gold and 3.5 g/t silver. At 31 December 1985, over 540 km of surface and underground drilling had been completed, comprising over 700 surface drillholes totalling 234 km of core and 218 km of open-hole drilling, and about 900 underground diamond-drillholes totalling 90 km. The Whenan Shaft had been sunk to 500 m and driving on three levels totalled almost 10 km. More than one million tonnes of ore and mullock were raised during development. A pilot treatment plant commissioned on site produced concentrates, matte and blister copper, and ammonium diuranate. Following a technical study of the Olympic Dam Project, completed in March 1985, and a subsequent economic feasibility study, it was announced on 11 June 1985 that the initial project was considered to be commercially viable. On 8 December 1985, the joint venturers, Western Mining Corporation Holdings Ltd (51%) and the BP Group (49%), announced their commitment to the Project. An appendix lists the important events that occurred between January 1986 and December 1987 in bringing Olympic Dam to the production state. 26 refs., 17 figs., 5 tabs., ills

  13. Nitrogen fixation in Acacia auriculiformis and Albizia lebbeck and their contributions to crop-productivity improvement

    International Nuclear Information System (INIS)

    Mbaya, N.; Mwange, K.Nk.; Luyindula, N.

    1998-01-01

    Pot and field experiments assessed N 2 fixation by Albizia lebbeck and Acacia auriculiformis and contributions from prunings to yields of corn and hibiscus. Nitrogen fixation in these tree legumes was poor, with less than 50% N derived from fixation (%Ndfa) when grown in pots, but higher (>70%) in field conditions, after inoculation with compatible Bradyrhizobium strains. Prunings from A. lebbeck, as green manure improved growth of maize and hibiscus, inducing greater corn-kernel yields than did urea. Acacia auriculiformis prunings were similarly beneficial when mixed with leaves of A. lebbeck or L. leucocephala. Application of slow- and fast-nutrient-releasing leaves is required to maximize their contributions to crop productivity. (author)

  14. In vitro evaluation of anti-microbial of the leaf extracts of acacia modesta

    International Nuclear Information System (INIS)

    Sulman, Z.; Khan, K.

    2014-01-01

    Infectious diseases caused by micro-organisms are transmissible and infect a large group of population. Investigations were carried out for studying the phytochemistry and biological potential of the leaves of Acacia modesta. Dried and finely ground leaves were extracted with ethanol. Different fractions were obtained by extracting the crude extract with n-hexane, chloroform and ethyl acetate. Fractions of n-hexane, chloroform, ethyl acetate, crude extract and the aqueous layer left behind were evaluated for their anti-microbial potential by determining the zone of inhibition against different bacterial strains. All fractions showed positive anti-bacterial activity except ethyl acetate fraction. However the aqueous layer showed activity which is significantly higher than the standard antibiotics used in this study. In conclusion the more active the compounds found in leaves, the more polar they were in nature. Bioassay guided isolation of these active compounds from aqueous fraction may lead to potential anti-bacterial metabolites from Acacia modesta. (author)

  15. Acacia tortilis subsp. heteracantha productivity in the Tugela Dry Valley Bushveld: preliminary results

    Directory of Open Access Journals (Sweden)

    S. J. Milton

    1983-11-01

    Full Text Available Acacia tortilis Hayne subsp.  heteracantha (Burch. Brenan dominates secondary succession in the Tugela Dry Valley Bushveld of the Natal midlands. The parts of KwaZulu in this veld type are impoverished, overpopulated and over-grazed. Preliminary results indicate that at a density of 2 700 ± 600 trees/ha there is a standing crop of c.2,87 t/ha (DM of acacia twigs suitable for hand pruning and milling into fodder, but that this is a costly process. Herbage biomass peaked at 0,73 t/ha (DM. Veld condition assessments suggested a stocking rate of|0,l AU/ha (grazers, but actual grazer stocking rates may be many times this density. It is recommended that the browser/grazer ratio be altered to make use of the c. 1,05 t/ha (DM of shoot growth produced annually by A. tortilis subsp.  heteracantha.

  16. Pretreatment of Acacia nilotica Sawdust by Catalytic Delignification and Its Fractal Kinetic Modeling

    Science.gov (United States)

    Mallick, Abhyuday; Ash, Soumendra Nath; Mahapatra, Debashis Kumar

    2016-04-01

    Alkaline delignification of Acacia nilotica heartwood has been carried out using 10 % Sodium hydroxide and Sodium sulphide as the cooking liquor. Delignification was carried out at 373, 393, 403 and 413 K on Acacia nilotica sawdust of particle-sizes 70, 100 and 120 mesh, for durations ranging from 1 to 3 h. The reactions were carried out in presence and in absence of Ferrous sulphate to determine its catalytic properties in delignification. Maximum delignification achieved was 82.7 %, based on Klason lignin, in 3 h at 413 K for 120 mesh feed. The activation energies for delignification were 20.9275 and 35 kJ/mol, respectively, in presence and in absence of Ferrous sulphate, indicating its significant catalytic effect. A kinetic model for delignification was developed by modification of the Nuclei Growth model. Delignification extent could be predicted from the developed model quite accurately, with R2 values ranging from 0.947 to 0.99.

  17. Acacia gum polysaccharide based hydrogel wound dressings: Synthesis, characterization, drug delivery and biomedical properties.

    Science.gov (United States)

    Singh, Baljit; Sharma, Sushma; Dhiman, Abhishek

    2017-06-01

    Keeping in view the importance of polysaccharide gums for wound care, in the present article, an attempt has been made to explore antioxidant nature of gum acacia in designing hydrogel wound dressing to improve its wound healing potential. These polymers were prepared by using acacia gum-polyvinylpyrollidone/carbopol and were characterized by 13 C NMR, FTIR, SEM, AFM, cryo-SEM, XRD, TGA, DSC and elemental analysis techniques. Some important biomaterial properties of wound dressings such as wound fluid absorption, haemo-compatibility, bioactive assessment, gaseous/water/microbial permeability, mechanical properties, bio-adhesion, drug release, and histology of wound healing were also determined. Hydrogel wound dressings were found non-haemolytic, antioxidant and mucoadhesive in nature. Release of drug occurred through non-Fickian diffusion mechanism and release profile best fitted in Higuchi model. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Dam Removals and River Restoration in International Perspective

    Directory of Open Access Journals (Sweden)

    Chris S. Sneddon

    2017-10-01

    Full Text Available In the Anthropocene era, questions over institutions, economics, culture and politics are central to the promotion of water-society relations that enhance biophysical resilience and democratic modes of environmental governance. The removal of dams and weirs from river systems may well signal an important shift in how human actors value and utilize rivers. Yet the removal of water infrastructure is often lengthy, institutionally complex, and characterized by social conflict. This Special Issue draws insights from case studies of recent efforts in North America and Europe to restore river systems through dam and weir removal. These cases include both instances where removal has come to fruition in conjunction with efforts to rehabilitate aquatic systems and instances where removal has been stymied by a constellation of institutional, political and cultural factors. Drawing from diverse theoretical frames and methodological approaches, the authors present novel ways to conceptualize water-society relations using the lens of dam removal and river restoration, as well as crucial reminders of the multiple biophysical and social dimensions of restoration initiatives for water resource practitioners interested in the rehabilitation of socioecological systems.

  19. Determination of metals in water from Billings dam, Sao Paulo

    International Nuclear Information System (INIS)

    Oliveira, Talita; Sarkis, Jorge E.S.; Ulrich, Joao C.; Yamaguishi, Renata Bazante; Menezes, Luciana Carvalho Bezerra de; Castro, Paula Maria Genova de; Monteiro Junior, Adalberto Jose; Maruyama, Lidia Sumile

    2013-01-01

    The Billings reservoir, located in Sao Paulo, Brazil, is used for several purposes such as: water supply, electric generation, fishing and leisure. Although considered an area of environmental protection, in recent years the dam has suffered diverse environmental aggressions including the release of toxic metals. This study presents a recent evaluation of metal contents along the Dam. Samples were collected every three months during the period of winter 2009 to summer 2010. Samples were collected in thirteen points along of the dam, as follows: Rio dos Porcos (Point 1), Summit Control (Point 2), Ilha do Bigua (Point 3), Casa Caida (Point 4), Barragem (Point 5), Foz de Taquacetuba (Point 6), Braco Borore (Point 7), Foz de Borore (Point 8), Alvarenga (Point 9), Pedreira (Point 10), Borore's Margin (Point 11), Capivari I's Margin (Point 12) and Capivari II's Margin (Point 13). The determination of Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn was performed by using high resolution inductively coupled plasma mass spectrometer (HR-ICPMS). The methodology has been validated using certified reference material Riverine Water Reference Material for Trace Metals provided by National Research Council Canada (NRCC). The sampling points located in the Pedreira, Borore's Margin, Alvarenga, Barragem Taquacetuba, Casa Caida e Ilha do Bigua presented the highest concentrations. The level for Fe, Cu and Ni were higher than the ones reported in the literature and above the limit set by CONAMA 2914/201. (author)

  20. Determination of metals in water from Billings dam, Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Talita; Sarkis, Jorge E.S.; Ulrich, Joao C.; Yamaguishi, Renata Bazante, E-mail: taoliveira@ipen.br, E-mail: jesarkis@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Menezes, Luciana Carvalho Bezerra de; Castro, Paula Maria Genova de; Monteiro Junior, Adalberto Jose; Maruyama, Lidia Sumile, E-mail: lcbm@usp.br [Instituto de Pesca, (IP/SAA-SP), Sao Paulo, SP (Brazil). Secretaria da Agricultura e Abastecimento do Estado de Sao Paulo

    2013-07-01

    The Billings reservoir, located in Sao Paulo, Brazil, is used for several purposes such as: water supply, electric generation, fishing and leisure. Although considered an area of environmental protection, in recent years the dam has suffered diverse environmental aggressions including the release of toxic metals. This study presents a recent evaluation of metal contents along the Dam. Samples were collected every three months during the period of winter 2009 to summer 2010. Samples were collected in thirteen points along of the dam, as follows: Rio dos Porcos (Point 1), Summit Control (Point 2), Ilha do Bigua (Point 3), Casa Caida (Point 4), Barragem (Point 5), Foz de Taquacetuba (Point 6), Braco Borore (Point 7), Foz de Borore (Point 8), Alvarenga (Point 9), Pedreira (Point 10), Borore's Margin (Point 11), Capivari I's Margin (Point 12) and Capivari II's Margin (Point 13). The determination of Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn was performed by using high resolution inductively coupled plasma mass spectrometer (HR-ICPMS). The methodology has been validated using certified reference material Riverine Water Reference Material for Trace Metals provided by National Research Council Canada (NRCC). The sampling points located in the Pedreira, Borore's Margin, Alvarenga, Barragem Taquacetuba, Casa Caida e Ilha do Bigua presented the highest concentrations. The level for Fe, Cu and Ni were higher than the ones reported in the literature and above the limit set by CONAMA 2914/201. (author)

  1. Évaluation des réseaux d'ACACIA | CRDI - Centre de recherches ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le programme Communautés et société de l'information en Afrique (ACACIA) du CRDI a choisi d'affecter une partie importante de son budget à des réseaux thématiques. Grâce à la subvention, une équipe internationale d'évaluateurs chevronnés, en collaboration avec la Section de l'évaluation du CRDI, évaluera dans ...

  2. TREATMENT OF SEEDS AND TYPES OF SUBSTRATUM IN THE PRODUCTION Acacia mearnsii SEEDLINGS

    OpenAIRE

    Lucas Zancan Pissinin; Joabel Barbieri; Darlan Michel Bonacina; Marlove Brião Muniz

    2008-01-01

    This paper evaluated the quality of Acacia mearnsii De Wild seedlings, produced from treated seeds with Vitavax +Thiran and with not-treated seeds. The seeds were sowed in four different substrates (commercial, soil from forests and sand) indifferent compositions. Laboratory sanity and germination evaluations in the seeds were made, and the seedlings evaluation wasmade at greenhouse. In sanity evaluation it was verified the seeds treatment efficiency only for Aspergillus flavus. In the germin...

  3. Green Chemistry in Water Treatment: Use of Coagulant Derived from Acacia mearnsii Tannin Extracts

    OpenAIRE

    Antonio S. Mangrich; Universidade Federal do Paraná; Marta Eliane Doumer; Universidade Federal do Paraná; Anderson S. Mallmannn; Tanac S/A; Carlos Rodolfo Wolf; Tanac S/A

    2014-01-01

    News coagulants for water and sewage treatment are synthesized trough the chemical transformation of tannin extracts.  Tanfloc is a cationic polymeric coagulant produced from tannin extract of Acacia mearnsii. In this paper we are supporting the use of cationic polymeric coagulant for treatment of polluted water instead of aluminum or iron salts to support the sustainable water supply systems according with the principles of the green chemistry. DOI: 10.5935/1984-6835.20140002 Novos coag...

  4. Karakteristik Spektra Absorbansi NIR (Near Infra Red) Spektroskopi Kayu Acacia mangium WILLD pada 3 Umur Berbeda

    OpenAIRE

    Karlinasari, Lina; Sabed, Merry; J. Wistara, Nyoman; Purwanto, Aris; Wijayanto, Hari

    2014-01-01

    Penelitian mengenai pengujian nondestruktif metode near infrared (NIR) spektroskopi di Indonesia masih sangat terbatas. Penelitian ini bertujuan untuk menentukan karakteristik spektra NIR spektroskopi (panjang gelombang 700 nm – 2500 nm) kayu Acacia mangium dari 3 umur yaitu 5, 6, dan, 7 tahun. Kayu mangium diperoleh dari daerah Maribaya, Parung Panjang, Bogor. Sampel contoh uji spektra terdiri dari bentuk solid atau padatan dan bentuk serbuk kayu. Hasil penelitian menunjukkan spektra absorba...

  5. Sifat Pulp Kimia-termomekanik (Ctmp) Ka Yu Mangium (Acacia Mangium Willd) Dari Berbagai Tingkat Umur

    OpenAIRE

    M, Rena; Siagian, Siagian; Roliadi, Han; Martua, Togar Hendrik

    2001-01-01

    This investigation deals with the assessment of mangium (Acacia mangium Willd.) wood plantation of various maturities for the manufactureof chemi-thermo-mechanical pulp (CTMP) with varying chemical (alkali) concentrations. The properties of CTMP examined were those related to its possibility for newsprint. The ages consisted of three levels (i.e. 6, 7 and 10 years) at which the respective mangium stands were normally harvested from their first rotation. Three ages groups, of mangium were fell...

  6. Biological Activity of Tannins from Acacia mangium Bark Extracted by Different Solvents

    OpenAIRE

    E. Wina; Susana I.W.R.; B. Tangendjaja

    2010-01-01

    Acacia mangium bark is abundant byproduct of wood industry in Indonesia. It is underutilized and mainly used as fire wood for the wood industry. The bark contains high level of tannin but the tannin has not been extracted or produced commercially. Tannin isolate can be used for several purposes such as tanning agent for leather, adhesive for plywood or particle board, etc. In ruminant, tannin can be detrimental but can also be beneficial. This experiment was aimed of getting the highest yield...

  7. New Pharmacophore from the Stem Bark Fractions of Acacia decurrens (Willd), an Invasive South Africa Tree

    OpenAIRE

    Okoli, Bamidele Joseph; Modise, Johannes Sekomeng

    2017-01-01

    The tolerance of Acacia decurrens, an invasive species, was exploited pharmacologically in this study. Phytochemical screening revealed important secondary metabolites. Importantly, the assay shows that ethyl acetate and methanol fractions are sources of phytochemicals compared to the hexane and chloroform fractions. A bioassay-guided in vitro assay of the extracts led to the eventual isolation of four bioactive compounds by column chromatography, identification, and characterisation with the...

  8. Key Impact Factors on Dam Break Fatalities

    Science.gov (United States)

    Huang, D.; Yu, Z.; Song, Y.; Han, D.; Li, Y.

    2016-12-01

    Dam failures can lead to catastrophes on human society. However, there is a lack of research about dam break fatalities, especially on the key factors that affect fatalities. Based on the analysis of historical dam break cases, most studies have used the regression analysis to explore the correlation between those factors and fatalities, but without implementing optimization to find the dominating factors. In order to understand and reduce the risk of fatalities, this study has proposed a new method to select the impact factors on the fatality. It employs an improved ANN (Artificial Neural Network) combined with LOOCV (Leave-one-out cross-validation) and SFS (Stepwise Forward Selection) approach to explore the nonlinear relationship between impact factors and life losses. It not only considers the factors that have been widely used in the literature but also introduces new factors closely involved with fatalities. Dam break cases occurred in China from 1954 to 2013 are summarized, within which twenty-five cases are selected with a comprehensive coverage of geographic position and temporal variation. Twelve impact factors are taken into account as the inputs, i.e., severity of dam break flood (SF), population at risk (PR), public understanding of dam break (UB), warning time (TW), evacuation condition (EC), weather condition during dam break (WB), dam break mode (MB), water storage (SW), building vulnerability (VB), dam break time (TB), average distance from the affected area to the dam (DD) and preventive measures by government (PG).From those, three key factors of SF, MB and TB are chosen. The proposed method is able to extract the key factors, and the derived fatality model performs well in various types of dam break conditions.

  9. National dam inventory provides data for analysis

    International Nuclear Information System (INIS)

    Spragens, L.

    1992-01-01

    The Association of State Dam Safety Officials completed a dam inventory this fall. Information on approximately 90,000 state-regulated dams in the US collected during the four-year inventory is being used to build a database managed by the Federal Emergency Management Agency. In addition to ASDSO's work, the federal government conducted an inventory of federal dams. This data will be added to the state information to form one national database. The database will feature 35 data fields for each entry, including the name of the dam, its size, the name of the nearest downstream community, maximum discharge and storage volume, the date of the last inspection, and details about the emergency action plan. The program is an update of the nation's first dam inventory, required by the Dam Safety Act of 1972. The US Army Corps of Engineers completed the original inventory in 1981. The Water Resources Development Act of 1986 authorized appropriations of $2.5 million for the Corps to update the inventory. FEMA and the Corps entered into an agreement for FEMA to undertake the task for the Corps and to coordinate work on both the federal and state inventories. ASDSO compiles existing information on state-regulated dams into a common format for the database, added missing information, and established a process for continually updating data. ASDSO plans to analyze the information collected for the database. It will look at statistics for the number of dams regulated, communities that could be affected, and the number of high-hazard dams. FEMA is preparing reports for Congress on the project. The reports, which are expected to be ready by May 1993, will include information on the methodology used and facts about regulated dams under state jurisdiction

  10. Fitness and its variation among populations of Acacia tortilis subsp ...

    African Journals Online (AJOL)

    Therefore, this study aims to determine if A. tortilis subsp. raddiana populations suffer reduced fitness and its correlation or association with genetic diversity and mating parameters. Correlations and association between fitness, population size, genetic variation, and mating system parameters were tested using Spearman ...

  11. Precipitation of calcium, magnesium, strontium and barium in tissues of four Acacia species (Leguminosae: Mimosoideae).

    Science.gov (United States)

    He, Honghua; Bleby, Timothy M; Veneklaas, Erik J; Lambers, Hans; Kuo, John

    2012-01-01

    Precipitation of calcium in plants is common. There are abundant studies on the uptake and content of magnesium, strontium and barium, which have similar chemical properties to calcium, in comparison with those of calcium in plants, but studies on co-precipitation of these elements with calcium in plants are rare. In this study, we compared morphologies, distributional patterns, and elemental compositions of crystals in tissues of four Acacia species grown in the field as well as in the glasshouse. A comparison was also made of field-grown plants and glasshouse-grown plants, and of phyllodes of different ages for each species. Crystals of various morphologies and distributional patterns were observed in the four Acacia species studied. Magnesium, strontium and barium were precipitated together with calcium, mainly in phyllodes of the four Acacia species, and sometimes in branchlets and primary roots. These elements were most likely precipitated in forms of oxalate and sulfate in various tissues, including epidermis, mesophyll, parenchyma, sclerenchyma (fibre cells), pith, pith ray and cortex. In most cases, precipitation of calcium, magnesium, strontium and barium was biologically induced, and elements precipitated differed between soil types, plant species, and tissues within an individual plant; the precipitation was also related to tissue age. Formation of crystals containing these elements might play a role in regulating and detoxifying these elements in plants, and protecting the plants against herbivory.

  12. [Discrimination of Rice Syrup Adulterant of Acacia Honey Based Using Near-Infrared Spectroscopy].

    Science.gov (United States)

    Zhang, Yan-nan; Chen, Lan-zhen; Xue, Xiao-feng; Wu, Li-ming; Li, Yi; Yang, Juan

    2015-09-01

    At present, the rice syrup as a low price of the sweeteners was often adulterated into acacia honey and the adulterated honeys were sold in honey markets, while there is no suitable and fast method to identify honey adulterated with rice syrup. In this study, Near infrared spectroscopy (NIR) combined with chemometric methods were used to discriminate authenticity of honey. 20 unprocessed acacia honey samples from the different honey producing areas, mixed? with different proportion of rice syrup, were prepared of seven different concentration gradient? including 121 samples. The near infrared spectrum (NIR) instrument and spectrum processing software have been applied in the? spectrum? scanning and data conversion on adulterant samples, respectively. Then it was analyzed by Principal component analysis (PCA) and canonical discriminant analysis methods in order to discriminating adulterated honey. The results showed that after principal components analysis, the first two principal components accounted for 97.23% of total variation, but the regionalism of the score plot of the first two PCs was not obvious, so the canonical discriminant analysis was used to make the further discrimination, all samples had been discriminated correctly, the first two discriminant functions accounted for 91.6% among the six canonical discriminant functions, Then the different concentration of adulterant samples can be discriminated correctly, it illustrate that canonical discriminant analysis method combined with NIR spectroscopy is not only feasible but also practical for rapid and effective discriminate of the rice syrup adulterant of acacia honey.

  13. Does aridity influence the morphology, distribution and accumulation of calcium oxalate crystals in Acacia (Leguminosae: Mimosoideae)?

    Science.gov (United States)

    Brown, Sharon L; Warwick, Nigel W M; Prychid, Christina J

    2013-12-01

    Calcium oxalate (CaOx) crystals are a common natural feature of many plant families, including the Leguminosae. The functional role of crystals and the mechanisms that underlie their deposition remain largely unresolved. In several species, the seasonal deposition of crystals has been observed. To gain insight into the effects of rainfall on crystal formation, the morphology, distribution and accumulation of calcium oxalate crystals in phyllodes of the leguminous Acacia sect. Juliflorae (Benth.) C. Moore & Betche from four climate zones along an aridity gradient, was investigated. The shapes of crystals, which include rare Rosanoffian morphologies, were constant between species from different climate zones, implying that morphology was not affected by rainfall. The distribution and accumulation of CaOx crystals, however, did appear to be climate-related. Distribution was primarily governed by vein density, an architectural trait which has evolved in higher plants in response to increasing aridity. Furthermore, crystals were more abundant in acacias from low rainfall areas, and in phyllodes containing high concentrations of calcium, suggesting that both aridity and soil calcium levels play important roles in the precipitation of CaOx. As crystal formation appears to be calcium-induced, we propose that CaOx crystals in Acacia most likely function in bulk calcium regulation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  14. Minor lipid components of some Acacia species: potential dietary health benefits of the unexploited seeds

    Directory of Open Access Journals (Sweden)

    Nasri Nizar

    2012-05-01

    Full Text Available Abstract Background Oilseed samples from four Acacia species ( A. cyclops, A. ligulata, A. salicina and A. cyanophylla were analyzed in order to evaluate the potential nutritional value of their unexploited seeds. Methods Samples were collected from different Tunisian geographic locations. Seed oils were extracted and carotenoids, tocopherols and sterols were analyzed using chromatographic methods. Results The studied Acacia seeds seem to be quite rich in lipids (from 6% to 12%. All Acacia species contain mainly the xanthophylls zeaxanthin and lutein compounds: from ca. 38 mg.kg-1 of total lipids (A. cyclops to ca. 113 mg.kg-1 of total lipids (A. cyanophylla. Total tocopherols varied from ca. 221 mg.kg-1 of total lipids (A. cyclops to ca. 808 mg.kg-1 of total lipids (A. ligulata. Sterols are highly present and their contents ranged between ca. 7 g. kg-1 of total lipids (A. salicina and 11 g. kg-1 of total lipids (A. cyclops. Conclusion This study highlights that these unexploited seeds might have a potential nutritional value and encourages researchers to more explore and find developments for these plants for healthy purposes.

  15. Productivity of Local Goats Supplemented with Acacia villosa and Coripha gebanga

    Directory of Open Access Journals (Sweden)

    A. M. Fuah

    2013-04-01

    Full Text Available Most feed for goats in the villages of West Timor, Indonesia, came from communal grazing areas, consist of native grass during wet season, crop residues and tree leaves (Sesbania and Acacia species in dry season. This study was aiming at examining the growth of goat supplemented with local feed. Twenty four goats were used, the average initial live weight was 12.5 kg. Four feeding treatments were applied: T1-200 g cut grass; T2–200 g Acacia villosa; T3–200 g Coripha gebanga; T4–100 g A. villosa + 100 g C. gebanga. Live weights and feed consumption were analyzed using repeated measures, analysis of variance. The average live weight showed a small increase, as well as daily weight gain of goats of which different significantly (P<0.05 amongst treatments (17, 36, 42, and 43 g/d/head, during the first 6 wk, followed by a sharp drop after 8 wk. The average supplemented feed consumption was 52, 35, 85, and 75 g/d/animal, for cut grass, A. villosa, C. gebanga, and A. villosa plus C. gebanga, respectively. Goats given C. gebanga and mixed Acacia and C. gebanga gave higher average weight gain, but also consumed more feed than those given cut grass or A.villosa (P<0.01. Supplementing feed to maintain growth of goats during dry seasons was better on A. villosa than on palm pith and its combination.

  16. Ecophysiological and foliar nitrogen concentration responses of understorey Acacia spp. and Eucalyptus sp. to prescribed burning.

    Science.gov (United States)

    Ma, Ling; Rao, Xingquan; Lu, Ping; Bai, Shahla Hosseini; Xu, Zhihong; Chen, Xiaoyang; Blumfield, Timothy; Xie, Jun

    2015-07-01

    Eucalyptus spp. is a dominant tree genus in Australia and most Eucalyptus spp. are canopy dominant species. In Australian natural forests, Eucalyptus spp. commonly are associated with understorey legumes which play a crucial role for ecological restoration owing to their nitrogen (N) fixing ability for replenishing the soil N lost after frequent prescribed burning. This study aimed to explore to what extent physiological responses of these species differ 7 and 12 years after last fire. Two most common understorey Acacia spp., Acacia leiocalyx and A. disparrima, as well as one non-leguminous Eucalyptus resinifera, were studied due to their dominance in the forest. Both A. leiocalyx and A. disparrima showed higher carbon (C) assimilation capacity, maximum photosynthetic capacity, and moderate foliar C/N ratio compared with E. resinifera. A. leiocalyx showed various advantages compared to A. disparrima such as higher photosynthetic capacity, adaptation to wider light range and higher foliar total N (TNmass). A. leiocalyx also relied on N2-fixing ability for longer time compared to A. disparrima. The results suggested that the two Acacia spp. were more beneficial to C and N cycles for the post burning ecosystem than the non-N2-fixing species E. resinifera. A. leiocalyx had greater contribution to complementing soil N cycle long after burning compared to A. disparrima.

  17. Digestibility Nutrient Contents on Acacia Seyal, Balanities Aegyptiaca and Chloris Gayana Hay

    International Nuclear Information System (INIS)

    Kiliti, J.K

    2002-01-01

    A study was carried to determine the nutrients and their digestibility in Acacia seyal and Balanities aegyptiaca legume browses and compared with Chloris gayana hay. Samples were taken from these two leguminous forages at Mogotio and Emining divisions of Koibatek district and fed to sheep in a change over design. The sheep were housed in individual pens and fitted with faecal collection bags. They were fed and faeces collected twice daily. An adaptation period of 14 days, Faecal collection of 7 days and changeover of 10 days were enforced. Nutrients analysed for during digestibility included DM, OM, CP, NDF, Hemicellulose and Cellulose. The nutrients compositions were 651, 916, 112, 370, 339, 59 and 84; 665, 920, 152, 443, 341, 89 and 80, 845, 924, 68, 730, 463, 57, and 76 for DM, OM, CP, NDF, ADF, and ash in Acacia seal, Balanities aegyptiaca and Chloris gayana hay. The in vivio digestibility results were different (p<0.05) for all nutrients. The digestibilities of DM, OM, CP NDF, Hemicellulose and Cellulose in Acacia seyal, Balanities aegyptiaca and Chloris gayana hay were 54.7, 66.5, 32.8, 40.3, 51.7, and 82.7; 48.5, 58.9, 67.4, 36.9, 36.3, and 40.6 and 48.1, 50.4, 41.7, 53.7, 63.0 and 62.3% respectively. The two legume forages had nutrients that had higher digestibility than hay except for fibre

  18. Genetic Variability Analysis of the Polyploid Complex of Acacia nilotica (L. Willd. Using RAPD Markers

    Directory of Open Access Journals (Sweden)

    Chevallier, MH.

    2008-01-01

    Full Text Available The genetic variability of nine Acacia nilotica subspecies of various origins was analyzed by thirty-six RAPD primers. Sixteen among them produced polymorphic bands and generated 166 polymorphic markers. The amplified bands were separated by electrophoresis on 1.8% agarose gel. The analysis of 166 RAPD markers allowed to distinguish essentially three main groups in Acacia nilotica complex: (i The first group comprised subspecies, indica, cupressiformis, nilotica, tomentosa. Subspecies subalata and jacquemontii of which the systematic position is unclear seems to belong to this group. (ii The second group comprised subspecies adstringens and leiocarpa. (iii Kraussiana subspecies distinguishes itself from first two groups. The genetic variability within populations (H was calculated through Shannon index. Subspecies adstringens presents the lowest within population variability (H= 0.015 while kraussiana and leiocarpa subspecies showed high variation index (H= 0.095 and (H= 0.096 respectively. The genetic variability analysis of Acacia nilotica revealed large differences between subspecies but no correlation between geographic distances and genetic distances could be established. Subspecies native of east Africa presented higher allelic richness than west African and Indian ones.

  19. After Three Gorges Dam: What have we learned?

    Science.gov (United States)

    Natali, J.; Williams, P.; Wong, R.; Kondolf, G. M.

    2013-12-01

    reservoir, subsequent floodplain development and degradation of levees increase downstream flood risk. As geomorphic adjustment continues, the loss of key fish and wildlife habitat will rise, a recognized but externalized environmental cost with potential mitigation measures found in protecting and restoring floodplain lakes. With significant underestimates of social impacts and project costs, the population of the surrounding area has experienced severe adverse impacts ranging from loss of ancient villages, landholdings, and livelihoods to increased threats of natural hazards -- without full compensation or public disclosure of project costs. The value of PPAs is most realized when integrated into adaptive management for river basin planning. Throughout the symposium, speakers echoed the conclusion: 'The entire Yangtze basin needs comprehensive management.' Integrated planning decisions must consider dams, water diversions, reservoir management, protection of natural areas, basin-wide land management, preservation of flood detention areas and levees, and both economic compensation and social opportunity for affected residents. The resulting analysis may influence the massive expansion of worldwide hydroelectric development as China exports its financing and dam building expertise.

  20. Detailed Chemical Composition of Condensed Tannins via Quantitative (31)P NMR and HSQC Analyses: Acacia catechu, Schinopsis balansae, and Acacia mearnsii.

    Science.gov (United States)

    Crestini, Claudia; Lange, Heiko; Bianchetti, Giulia

    2016-09-23

    The chemical composition of Acacia catechu, Schinopsis balansae, and Acacia mearnsii proanthocyanidins has been determined using a novel analytical approach that rests on the concerted use of quantitative (31)P NMR and two-dimensional heteronuclear NMR spectroscopy. This approach has offered significant detailed information regarding the structure and purity of these complex and often elusive proanthocyanidins. More specifically, rings A, B, and C of their flavan-3-ol units show well-defined and resolved absorbance regions in both the quantitative (31)P NMR and HSQC spectra. By integrating each of these regions in the (31)P NMR spectra, it is possible to identify the oxygenation patterns of the flavan-3-ol units. At the same time it is possible to acquire a fingerprint of the proanthocyanidin sample and evaluate its purity via the HSQC information. This analytical approach is suitable for both the purified natural product proanthocyanidins and their commercial analogues. Overall, this effort demonstrates the power of the concerted use of these two NMR techniques for the structural elucidation of natural products containing labile hydroxy protons and a carbon framework that can be traced out via HSQC.

  1. Podridão-do-lenho em plantios homogêneos de Acacia mangium Heartrot in homogeneous stands of Acacia mangium

    Directory of Open Access Journals (Sweden)

    Bernardo de Almeida Halfeld-Vieira

    2006-04-01

    Full Text Available O objetivo deste trabalho foi relatar a ocorrência da podridão-do-lenho em plantios homogêneos de Acacia mangium no Estado de Roraima. A observação dos sintomas iniciais em ferimentos de poda indica que a desrama artificial é um fator de predisposição. Estimativas realizadas em dois talhões comerciais constataram cerca de 8 e 39% de incidência da doença em árvores de três anos. Isolamentos a partir de árvores sintomáticas e testes de patogenicidade demonstram que Lasiodiplodia theobromae pode contribuir no processo de podridão. Este é o primeiro relato da podridão-do-lenho em A. mangium no Brasil, o que pode limitar sua exploração comercial.The objective of this work was to report the occurrence of heartrot in homogeneous stands of Acacia mangium in the State of Roraima, Brazil. Observations of symptoms initiating from pruning wounds indicated that the artificial pruning is a predisposing factor. A survey carried out in two commercial stands showed 8 and 39% of disease incidence in three-year-old trees. Isolations performed from symptomatic trees and pathogenicity tests demonstrated that the fungus Lasiodiplodia theobromae can incite the rot development. This is the first record of A. mangium heartrot in Brazil. The disease can restrict its commercial exploration.

  2. Proceedings of the Canadian dam safety conference

    International Nuclear Information System (INIS)

    1993-01-01

    A conference was held to discuss dam safety. Papers were presented concerning public policy and legislative issues, standards, guidelines and criteria, dam safety reviews, operations and maintenance, technical issues, and case histories. Separate abstracts have been prepared for 18 papers from the conference

  3. The environmental and social acceptability of dams

    OpenAIRE

    Boyé, Henri; Vivo, Michel de

    2016-01-01

    Dams are an ever more vital tool for addressing our growing water needs and the emergence of new challenges such as sustainable development and climate change. However, these infrastructures are still highly controversial around the world. Citing numerous examples, this paper goes over the main points of debate around dams, and the necessary conditions for securing their acceptability.

  4. Descriptive characteristics of the large Italian dams

    International Nuclear Information System (INIS)

    Dello Vicario, E.; Petaccia, A.; Savanella, V.

    1999-01-01

    In the present note the characteristics of the Italian dams are examined, underlining, in a statistical view, story, geographical location, types and use of the most important works. Such a review can be useful for a more detailed analysis, both for the dams characterization and for further studies relevant to water resources utilization [it

  5. Proceedings of the CDSA/CANCOLD Joint Dam Safety Conference

    International Nuclear Information System (INIS)

    1997-01-01

    The 1997 conference on large dams was co-sponsored by the Canadian Dam Safety Association and the Canadian National Committee of the International Commission on Large Dams. The conference was held in Montreal in September. A total of 31 papers were presented in seven sessions. Session One was devoted to the 1996 Saguenay Floods, while other sessions dealt with risk management in relation to dams, dam safety programs, embankment dams, and monitoring of dams. A two-part session dealt with issues related to the construction and repair of concrete dams. refs., figs

  6. The Impact of Dam-Reservoir-Foundation Interaction on Nonlinear Response of Concrete Gravity Dams

    Science.gov (United States)

    Amini, AliReza; Motamedi, Mohammad Hossein; Ghaemian, Mohsen

    2008-07-01

    To study the impact of dam-reservoir-foundation interaction on nonlinear response of concrete gravity dams, a two-dimensional finite element model of a concrete gravity dam including the dam body, a part of its foundation and a part of the reservoir was made. In addition, the proper boundary conditions were used in both reservoir and foundation in order to absorb the energy of outgoing waves at the far end boundaries. Using the finite element method and smeared crack approach, some different seismic nonlinear analyses were done and finally, we came to a conclusion that the consideration of dam-reservoir-foundation interaction in nonlinear analysis of concrete dams is of great importance, because from the performance point of view, this interaction significantly improves the nonlinear response of concrete dams.

  7. The Impact of Dam-Reservoir-Foundation Interaction on Nonlinear Response of Concrete Gravity Dams

    International Nuclear Information System (INIS)

    Amini, Ali Reza; Motamedi, Mohammad Hossein; Ghaemian, Mohsen

    2008-01-01

    To study the impact of dam-reservoir-foundation interaction on nonlinear response of concrete gravity dams, a two-dimensional finite element model of a concrete gravity dam including the dam body, a part of its foundation and a part of the reservoir was made. In addition, the proper boundary conditions were used in both reservoir and foundation in order to absorb the energy of outgoing waves at the far end boundaries. Using the finite element method and smeared crack approach, some different seismic nonlinear analyses were done and finally, we came to a conclusion that the consideration of dam-reservoir-foundation interaction in nonlinear analysis of concrete dams is of great importance, because from the performance point of view, this interaction significantly improves the nonlinear response of concrete dams

  8. Restoring Environmental Flows by Modifying Dam Operations

    Directory of Open Access Journals (Sweden)

    Brian D. Richter

    2007-06-01

    Full Text Available The construction of new dams has become one of the most controversial issues in global efforts to alleviate poverty, improve human health, and strengthen regional economies. Unfortunately, this controversy has overshadowed the tremendous opportunity that exists for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. This paper describes an assessment framework that can be used to evaluate the benefits that might be restored through dam re-operation. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. The paper highlights a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the

  9. Groundwater Forecasting Optimization Pertain to Dam Removal

    Science.gov (United States)

    Brown, L.; Berthelote, A. R.

    2011-12-01

    There is increasing interest in removing dams due to changing ecological and societal values. Groundwater recharge rate is closely connected to reservoir presence or absence. With the removal of dams and their associated reservoirs, reductions in groundwater levels are likely to impact water supplies for domestic, industrial and agricultural use. Therefore accessible economic and time effective tools to forecast groundwater level declines with acceptable uncertainty following dam removals are critical for public welfare and healthy regional economies. These tools are also vital to project planning and provide beneficial information for restoration and remediation managements. The standard tool for groundwater forecasting is 3D Numerical modeling. Artificial Neural Networks (ANNs) may be an alternative tool for groundwater forecasting pertain to dam removal. This project compared these two tools throughout the Milltown Dam removal in Western Montana over a five year period. It was determined that ANN modeling had equal or greater accuracy for groundwater forecasting with far less effort and cost involved.

  10. Research progress on dam-break floods

    KAUST Repository

    Wu, Jiansong

    2011-08-01

    Because of the catastrophic effects downstream of dam-break failure, more and more researchers around the world have been working on the study of dam-break flows to accurately forecast the downstream inundation mapping. With the rapid development of computer hardware and computing techniques, numerical study on dam-break flows has been a popular research subject. In the paper, the numerical methodologies used to solve the governing partial differential equations of dam-break flows are classified and summarized, and their characteristics and applications are discussed respectively. Furthermore, the fully-developed mathematical models developed in recent decades are reviewed, and also introduced the authors\\' on-going work. Finally, some possible future developments on modeling the dam-break flows and some solutions are presented and discussed. © 2011 IEEE.

  11. 'Dam it - it's easy!' - or is it?

    Science.gov (United States)

    Marshall, K

    2017-06-09

    Dentists the world over seem to still have issues in making rubber dam application a routine part of practice, even in situations where patients are obviously at risk. In this article, the author - who has delivered hundreds of seminars and hands on tuition in a quick and easy method of dam application (the 'Dam it - it's Easy!' series) to dentists in the UK, Europe, North America and Asia - highlights the similarity of the misconceptions existing in regard to its use by dentists the world over. The valuable advantages to the environment in the dental treatment room by dental dam application are considered underused. The protection offered by routine rubber dam application is second to none in situations that are potentially physically hazardous to patients.

  12. Knowledge and understanding of dissolved solids in the Rio Grande–San Acacia, New Mexico, to Fort Quitman, Texas, and plan for future studies and monitoring

    Science.gov (United States)

    Moyer, Douglas; Anderholm, Scott K.; Hogan, James F.; Phillips, Fred M.; Hibbs, Barry J.; Witcher, James C.; Matherne, Anne Marie; Falk, Sarah E.

    2013-01-01

    Availability of water in the Rio Grande Basin has long been a primary concern for water-resource managers. The transport and delivery of water in the basin have been engineered by using reservoirs, irrigation canals and drains, and transmountain-water diversions to meet the agricultural, residential, and industrial demand. In contrast, despite the widespread recognition of critical water-quality problems, there have been minimal management efforts to improve water quality in the Rio Grande. Of greatest concern is salinization (concentration of dissolved solids approaching 1,000 mg/L), a water-quality problem that has been recognized and researched for more than 100 years because of the potential to limit both agricultural and municipal use. To address the issue of salinization, water-resource managers need to have a clear conceptual understanding of the sources of salinity and the factors that control storage and transport, identify critical knowledge gaps in this conceptual understanding, and develop a research plan to address these gaps and develop a salinity management program. In 2009, the U.S. Geological Survey (USGS) in cooperation with the U.S. Army Corps of Engineers (USACE), New Mexico Interstate Stream Commission (NMISC), and New Mexico Environment Department (NMED) initiated a project to summarize the current state of knowledge regarding the transport of dissolved solids in the Rio Grande between San Acacia, New Mexico, and Fort Quitman, Texas. The primary objective is to provide hydrologic information pertaining to the spatial and temporal variability present in the concentrations and loads of dissolved solids in the Rio Grande, the source-specific budget for the mass of dissolved solids transported along the Rio Grande, and the locations at which dissolved solids enter the Rio Grande. Dissolved-solids concentration data provide a good indicator of the general quality of surface water and provide information on the factors governing salinization within

  13. Risk assessment, eradication, and biological control: global efforts to limit Australian acacia invasions

    Science.gov (United States)

    Wilson, John R.U.; Gairifo, Carla; Gibson, Michelle R.; Arianoutsou, Margarita; Bakar, Baki B.; Baret, Stephane; Celesti-Grapow, Laura; DiTomaso, Joseph M.; Dufour-Dror, Jean-Marc; Kueffer, Christoph; Kull, Christian A.; Hoffman, John H.; Impson, Fiona A.C.; Loope, Lloyd L.; Marchante, Elizabete; Harchante, Helia; Moore, Joslin L.; Murphy, Daniel J.; Tassin, Jacques; Witt, Arne; Zenni, Rafael D.; Richardson, David M.

    2011-01-01

    Aim Many Australian Acacia species have been planted around the world, some are highly valued, some are invasive, and some are both highly valued and invasive. We review global efforts to minimize the risk and limit the impact of invasions in this widely used plant group. Location Global. Methods Using information from literature sources, knowledge and experience of the authors, and the responses from a questionnaire sent to experts around the world, we reviewed: (1) a generalized life cycle of Australian acacias and how to control each life stage, (2) different management approaches and (3) what is required to help limit or prevent invasions. Results Relatively few Australian acacias have been introduced in large numbers, but all species with a long and extensive history of planting have become invasive somewhere. Australian acacias, as a group, have a high risk of becoming invasive and causing significant impacts as determined by existing assessment schemes. Moreover, in most situations, long-lived seed banks mean it is very difficult to control established infestations. Control has focused almost exclusively on widespread invaders, and eradication has rarely been attempted. Classical biological control is being used in South Africa with increasing success. Main conclusions A greater emphasis on pro-active rather than reactive management is required given the difficulties managing established invasions of Australian acacias. Adverse effects of proposed new introductions can be minimized by conducting detailed risk assessments in advance, planning for on-going monitoring and management, and ensuring resources are in place for long-term mitigation. Benign alternatives (e.g. sterile hybrids) could be developed to replace existing utilized taxa. Eradication should be set as a management goal more often to reduce the invasion debt. Introducing classical biological control agents that have a successful track-record in South Africa to other regions and identifying new

  14. Do we need construct more dams?

    Science.gov (United States)

    Chen, J.; Shi, H.

    2013-12-01

    This paper reviews global dam development in association with the growths of global population, economy, and energy consumption in the past several decades, and also evaluates contributions of dam development to future world sustainable development. Eventually, this paper answers whether we need more dams in the future or not. The world population has rapidly increased from 1.6 billion in 1900, 2.5 billion in 1950, 6.1 billion in 2000, to 7.0 billion in 2011, and is projected to reach 9.5 billion in 2050; similarly, the world economy has dramatically expanded. To maintain socioeconomic development, the consumption of water, food and energy has increased rapidly as well. However, the total volume of available water resource over the world is limited, the food production largely depends on water supply, and the main energy sources are still oil, coal and gas at present, which are regarded as non-renewable resources. Accordingly, it is expected that we will face serious problems to deal with the challenges of water crisis, food security and energy shortage in the near future. In order to enhance the capability of regulating water resource, a great number of global dams (and related reservoirs) have been constructed in the last one hundred years; currently, almost all large rivers over the world have been regulated by dams. The reservoirs can supply sufficient water for irrigated land to ensure food production, and the associated hydropower stations can generate electricity. This article collects the dam data from the ICOLD (International Commission on Large Dams) and GRanD (Global Reservoir and Dam) databases, and some socioeconomic data, including population, economy, and consumptions of water, food and energy over the world. Analysis of these data reveals that global dam development has a great impact on the world sustainable development. Further, it is concluded that we need further dam development to maintain our future development.

  15. Fluvial wood function downstream of beaver versus man-made dams in headwater streams in Massachusetts, USA

    Science.gov (United States)

    David, G. C.; DeVito, L. F.; Munz, K. T.; Lisius, G.

    2014-12-01

    Fluvial wood is an essential component of stream ecosystems by providing habitat, increasing accumulation of organic matter, and increasing the processing of nutrients and other materials. However, years of channel alterations in Massachusetts have resulted in low wood loads despite the afforestation that has occurred since the early 1900s. Streams have also been impacted by a large density of dams, built during industrialization, and reduction of the beaver population. Beavers were reintroduced to Massachusetts in the 1940s and they have since migrated throughout the state. Beaver dams impound water, which traps sediment and results in the development of complex channel patterns and more ecologically productive and diverse habitats than those found adjacent to man-made dams. To develop better management practices for dam removal it is essential that we understand the geomorphic and ecologic function of wood in these channels and the interconnections with floodplain dynamics and stream water chemistry. We investigate the connections among fluvial wood, channel morphology, floodplain soil moisture dynamics, and stream water chemistry in six watersheds in Massachusetts that have been impacted by either beaver or man-made dams. We hypothesize that wood load will be significantly higher below beaver dams, subsequently altering channel morphology, water chemistry, and floodplain soil moisture. Reaches are surveyed up- and downstream of each type of dam to better understand the impact dams have on the fluvial system. Surveys include a longitudinal profile, paired with dissolved oxygen and ammonium measurements, cross-section and fluvial wood surveys, hydraulic measurements, and floodplain soil moisture mapping. We found that dissolved oxygen mirrored the channel morphology, but did not vary significantly between reaches. Wood loads were significantly larger downstream of beaver dams, which resulted in significant changes to the ammonium levels. Floodplain soil moisture

  16. The role of dams in development

    International Nuclear Information System (INIS)

    Cakmak, C.

    2001-01-01

    Although the amounts of water resources are enough for the entire world, the distribution of them in time and space shows uneven pattern. The water need is increasing with heavy industrial and agricultural requirements, while available water in the world remains as a fixed source. Economic growth, socio-cultural, and environmental developments are being realized following these changes. In order to achieve sustainable management of water resources, these changes have to be taken into consideration in water-related development projects. Demand for water is steadily increasing through out the world, even though the fresh water resources are limited and unevenly distributed, during the past three centuries, the amount of water withdrawn from fresh water resources has increased by a factor of 35, whereas world population by a factor 8. The engineering of dams, which provides regular water from reservoirs of dams to be used in case of demand pattern, is a vital part of the civilization. Dams have played a key rote in the development since the third millennium B C when the first great civilizations evolved on major rivers, such as Tigris-Euphrates, the Nile and the Indus. From these early times dams were built for flood control, water supply, irrigation and navigation. Dams also had been built to produce motive power and electricity since the industrial revolution. Development priorities changed, experience accumulated with the construction and operation of dams. Although the importance of water is well known in the human life and civilization around the world, still various groups argue that expected economic benefits are not being produced and that major environmental, economic and social costs are not being taken into account. By the end of 20th century, there were 45000 large dams in over 150 countries. According to the same classification there are 625 large dams in Turkey. All over the world, 50 % of the large dams were built mainly for irrigation. It is estimated

  17. Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

    Science.gov (United States)

    Kalkan, Y.; Bilgi, S.

    2014-12-01

    Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the

  18. The Effect of Sonic Bloom Fertilizing Technology on The Seed Germination and Growth of Acacia mangium Willd Seedling

    Directory of Open Access Journals (Sweden)

    Mulyadi A T

    2012-11-01

    Full Text Available Acacia mangium Willd is one of the promising wood species, it is a fast growing species and can be used as raw materials for pulp, furniture and wood working. Musi Hutan Persada Company has planted Acacia mangium Willd in large scale for pulp processing raw materials and for wood working industry. The faculty of forestry of the Nusa Bangsa University in collaboration with the Musi Hutan Persada have examined  the effect of “Sonic Bloom” to the Acacia mangium Willd germination and seedling growth. The results of the research are the following : (1 The seed germination with “Sonic Bloom” provided percented of germination of 82%, better than those without “Sonic Bloom”, i.e. only 34%; (2 With Sonic Bloom,  the height of 80-days old seedling is 129.6 cm higher than those without “Sonic Bloom”of only 90.7 cm  ; (3 the diameter of 80-days old seedling with “Sonic Bloom” is 0,24 cm higher than those without “Sonic Bloom” harving diameters of only 0.19 cm.The study concludes that sonic bloom treatment is very useful for the seed germination and the growth of Acacia mangium Willd seedling Key Words : Sonic Bloom, persemaian, Acacia mangium, perkecambahan, bibit   Normal 0 false false false IN X-NONE X-NONE

  19. The Manantali dam. Synthesis report

    International Nuclear Information System (INIS)

    Dickmann, M.; Sieburger, Dr; Ficatier, M.; Naudet, M.; Schmidt, M.; Seve, M.

    2009-01-01

    This report proposes an ex-post assessment of the Manantali dam on the Senegal river and of the related investments in Senegal, in Mauritania and in Mali. After a presentation of the methodology adopted for this assessment study performed by several organisms, the report describes the context and the concerned sectors: project costs and funding, framework for irrigated agriculture, and framework for energy. It discusses the relevance of the project with respect to irrigated agriculture and to energy. It assesses the project performance in terms of efficiency and of viability, and with respect to environmental aspects. It presents an overview of the different direct and indirect sector-based partners which are involved in energy or rural development. The next part proposes an assessment of the global impact of the project on development as far as irrigated agriculture, the energy sector, and regional cooperation and integration are concerned. A set of lessons learned and recommendations are then formulated

  20. Dam construction in salt rock

    International Nuclear Information System (INIS)

    Stockmann, N.; Beinlich, A.; Flach, D.; Jockwer, N.; Klarr, K.; Krogmann, P.; Miehe, R.; Schmidt, M.W.; Schwaegermann, H.F.; Walter, F.; Yaramanci, U.

    1991-11-01

    Barriers are a major component of the satefy concept for the Gorleben repository. The construction and performance of dams are currently tested within the framework of a project carried out in the Asse salt mine. A measuring programme has been established to give evidence of the sealing capacities of a barrier consisting of an abatement, long-term sealing material, and a hydraulic sealing system. Tests are to be made to verify the barrier's performance for shorter of long time periods (up to about 500 years). The tests are assisted by computed models established for the project. The long-term safety aspects to be studied include such conditions as permeability changes due to mechanical impacts, circulation conditions at the roadside, and the serviceable life and efficiency of the sealing components. (DG) [de

  1. Wind-Driven Ecological Flow Regimes Downstream from Hydropower Dams

    Science.gov (United States)

    Kern, J.; Characklis, G. W.

    2012-12-01

    challenge, the following study was designed to investigate the potential for wind power integration to alter riparian flow regimes below hydroelectric dams. A hydrological model of a three-dam cascade in the Roanoke River basin (Virginia, USA) is interfaced with a simulated electricity market (i.e. a unit commitment problem) representing the Dominion Zone of PJM Interconnection. Incorporating forecasts of electricity demand, hydro capacity and wind availability, a mixed-integer optimization program minimizes the system cost of meeting hourly demand and reserve requirements by means of a diverse generation portfolio (e.g. nuclear, fossil, hydro, and biomass). A secondary 'balancing' energy market is executed if real-time wind generation is less than the day-ahead forecast, calling upon reserved generation resources to meet the supply shortfall. Hydropower release schedules are determined across a range of wind development scenarios (varying wind's fraction of total installed generating capacity, as well as its geographical source region). Flow regimes for each wind development scenario are compared against both historical and simulated flows under current operations (negligible wind power), as well as simulated natural flows (dam removal), in terms of ecologically relevant flow metrics. Results quantify the ability of wind power development to alter within-week stream flows downstream from hydropower dams.

  2. TYPOLOGY OF LARGE DAMS. A REVIEW

    Directory of Open Access Journals (Sweden)

    Gheorghe ROMANESCU

    2015-06-01

    Full Text Available The dams represent hydrotechnical constructions meant to ensure a judicious use of water resources. The international literature is extremely rich in data regarding the large dams on Earth. In this context, a hierarchy of the main dams is attempted and the role they play in the economic development of the regions they were built in is underlined. The largest dams are built on the big rivers in Asia, North America, South America and Africa. The reservoirs have multiple roles: electricity production, drinking or industrial water supply, irrigations, recreation, etc. High costs and land fragility do not allow the construction of dams in the places most affected by drought or flood. This is why they are usually built in mountainous areas, at great distance from the populated centres. On the Romanian territory, there are 246 large dams, built in the hydrographical basins of Siret, Olt, Arges, Somes, etc. The largest rivers on Earth, by discharge, (Amazon and Zair do not also include the largest dams because the landform and the type of flow have not allowed such constructions.

  3. The effects of passage through the gut of goats and cattle, and the application of dung as a fertiliser on seedling establishment of Dichrostachys cinerea and Acacia nilotica

    CSIR Research Space (South Africa)

    Tjelele, TJ

    2015-02-01

    Full Text Available Seed pods of Dichrostachys cinerea and Acacia nilotica have higher nutritive value than grasses and other browse plants during the dry season and form an important part of the diet of livestock. Seeds of Acacia may be destroyed during passage...

  4. In vitro antioxidant and antimalarial activities of leaves, pods and bark extracts of Acacia nilotica (L.) Del.

    Science.gov (United States)

    Sadiq, Muhammad Bilal; Tharaphan, Pattamon; Chotivanich, Kesinee; Tarning, Joel; Anal, Anil Kumar

    2017-07-18

    The emergence of drug resistant malaria is threatening our ability to treat and control malaria in the Southeast Asian region. There is an urgent need to develop novel and chemically diverse antimalarial drugs. This study aimed at evaluating the antimalarial and antioxidant potentials of Acacia nilotica plant extracts. The antioxidant activities of leaves, pods and bark extracts were determined by standard antioxidant assays; reducing power capacity, % lipid peroxidation inhibition and ferric reducing antioxidant power assay. The antimalarial activities of plant extracts against Plasmodium falciparum parasites were determined by the 48 h schizont maturation inhibition assay. Further confirmation of schizonticide activity of extracts was made by extending the incubation period up to 96 h after removing the plant extract residues from parasites culture. Inhibition assays were analyzed by dose-response modelling. In all antioxidant assays, leaves of A. nilotica showed higher antioxidant activity than pods and bark. Antimalarial IC 50 values of leaves, pods and bark extracts were 1.29, 4.16 and 4.28 μg/ml respectively, in the 48 h maturation assay. The IC 50 values determined for leaves, pods and bark extracts were 3.72, 5.41 and 5.32 μg/ml respectively, after 96 h of incubation. All extracts inhibited the development of mature schizont, indicating schizonticide activity against P. falciparum. A. nilotica extracts showed promising antimalarial and antioxidant effects. However, further investigation is needed to isolate and identify the active components responsible for the antimalarial and antioxidant effects.

  5. The Dams and Monitoring Systems and Case Study: Ataturk and Karakaya Dams

    Science.gov (United States)

    Kalkan, Y.; Bilgi, S.; Gülnerman, A. G.

    2017-12-01

    Dams are among the most important engineering structures used for flood controls, agricultural purposes as well as drinking and hydroelectric power. Especially after the Second World War, developments on the construction technology, increase the construction of larger capacity dams. There are more than 150.000 dams in the world and almost 1000 dams in Turkey, according to international criteria. Although dams provide benefits to humans, they possess structural risks too. To determine the performance of dams on structural safety, assessing the spatial data is very important. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some general information on dams and their different monitoring systems by taking into account two different dams and their structural specifications with the required information. The case study in this paper depends on a comparison of the monitoring surveys on Atatürk Dam and Karakaya Dam, which are constructed on Firat River with two different structural

  6. Wood ash treatment, a cost-effective way to deactivate tannins in Acacia cyanophylla Lindl. foliage and to improve digestion by Barbarine sheep

    International Nuclear Information System (INIS)

    Ben Salem, H.; Abidi, S.; Makkar, H.P.S.; Nefzaoui, A.

    2005-01-01

    Three in vitro experiments and one in vivo experiment were carried out to study the effect of wood ash sources (6 L wood ash solution/kg fresh plant leaves) and levels and treatment duration on the nutritive value of acacia leaves. In Experiment 1, samples of fresh (F), dried (D), or dried and ground (DG) acacia were soaked for 6 h in water or acacia wood ash solution (120 g of wood ash dry matter/L of water). Soaking acacia in water decreased total extractable phenols (TP), total extractable tannins (TT) and extractable condensed tannins (CT). Wood ash treatment led to a further decrease of these phenolic compounds and was highest with DG acacia. Experiment 2 investigated different levels of acacia wood ash (0, 120, 180 and 240 g wood ash dry matter/L of water) and treatment duration (1, 2 and 3 days). The higher the level of wood ash, the lower proportion of TP and CT in acacia was noted. In Experiment 3, two sources of wood ash (i.e., acacia and Aleppo pine) and the same solution of each source of wood ash were used eight times. The two sources of wood ash had similar deactivating effect on TP and CT. The rate of decrease of TP and CT was highest when the same wood ash solution was used four consecutive times and decreased progressively thereafter. In these three experiments, water and wood ash treatment reduced organic matter and crude protein content but substantially increased the neutral detergent fibre (NDFom) content of treated acacia. In the fourth experiment, we treated acacia with acacia wood ash (180 g/L of water for 2 days) and the same solution was used five times. Treated and untreated acacia were air-dried and fed ad libitum to two groups, each of four Barbarine rams together with 300 g of concentrate. Wood ash treatment did not affect intake and OM digestibility of the diet but increased crude protein and NDFom digestibility (P < 0.05). Feeding untreated acacia resulted in negative N balances but with wood ash treatment, N balance was positive

  7. Wood ash treatment, a cost-effective way to deactivate tannins in Acacia cyanophylla Lindl. foliage and to improve digestion by Barbarine sheep

    Energy Technology Data Exchange (ETDEWEB)

    Ben Salem, H. [Institut National de la Recherche Agronomique de Tunisie (INRAT), Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia)]. E-mail: bensalem.hichem@iresa.agrinet.tn; Abidi, S. [Institut National de la Recherche Agronomique de Tunisie (INRAT), Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia); Ecole Superieure d' Agriculture de Mateur, Mateur (Tunisia); Makkar, H.P.S. [Animal Production and Health Section, Joint FAO/IAEA Division, International Atomic Energy Agency, Vienna (Austria); Nefzaoui, A. [Institut National de la Recherche Agronomique de Tunisie (INRAT), Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia)

    2005-08-19

    Three in vitro experiments and one in vivo experiment were carried out to study the effect of wood ash sources (6 L wood ash solution/kg fresh plant leaves) and levels and treatment duration on the nutritive value of acacia leaves. In Experiment 1, samples of fresh (F), dried (D), or dried and ground (DG) acacia were soaked for 6 h in water or acacia wood ash solution (120 g of wood ash dry matter/L of water). Soaking acacia in water decreased total extractable phenols (TP), total extractable tannins (TT) and extractable condensed tannins (CT). Wood ash treatment led to a further decrease of these phenolic compounds and was highest with DG acacia. Experiment 2 investigated different levels of acacia wood ash (0, 120, 180 and 240 g wood ash dry matter/L of water) and treatment duration (1, 2 and 3 days). The higher the level of wood ash, the lower proportion of TP and CT in acacia was noted. In Experiment 3, two sources of wood ash (i.e., acacia and Aleppo pine) and the same solution of each source of wood ash were used eight times. The two sources of wood ash had similar deactivating effect on TP and CT. The rate of decrease of TP and CT was highest when the same wood ash solution was used four consecutive times and decreased progressively thereafter. In these three experiments, water and wood ash treatment reduced organic matter and crude protein content but substantially increased the neutral detergent fibre (NDFom) content of treated acacia. In the fourth experiment, we treated acacia with acacia wood ash (180 g/L of water for 2 days) and the same solution was used five times. Treated and untreated acacia were air-dried and fed ad libitum to two groups, each of four Barbarine rams together with 300 g of concentrate. Wood ash treatment did not affect intake and OM digestibility of the diet but increased crude protein and NDFom digestibility (P < 0.05). Feeding untreated acacia resulted in negative N balances but with wood ash treatment, N balance was positive

  8. Developing an integrated dam safety program

    International Nuclear Information System (INIS)

    Nielsen, N. M.; Lampa, J.

    1996-01-01

    An effort has been made to demonstrate that dam safety is an integral part of asset management which, when properly done, ensures that all objectives relating to safety and compliance, profitability, stakeholders' expectations and customer satisfaction, are achieved. The means to achieving this integration of the dam safety program and the level of effort required for each core function have been identified using the risk management approach to pinpoint vulnerabilities, and subsequently to focus priorities. The process is considered appropriate for any combination of numbers, sizes and uses of dams, and is designed to prevent exposure to unacceptable risks. 5 refs., 1 tab

  9. Predictions of total deformations in Jebba main dam by finite ...

    African Journals Online (AJOL)

    This paper examined the deformations of the Jebba Main Dam, Jebba Nigeria using the finite element method. The study also evaluated the predicted deformations and compared them with the actual deformations in the dam to identify possible causes of the observed longitudinal crack at the dam crest. The Jebba dam is a ...

  10. The geomorphic legacy of small dams — An Austrian study

    NARCIS (Netherlands)

    Poeppl, R.E.; Keesstra, S.D.; Hein, T.

    2015-01-01

    Dams represent one of the most dominant forms of human impact upon fluvial systems during the Anthropocene, as they disrupt the downstream transfer of water and sediments. Removing dams restores river continuity and channel morphology. Both dam construction and dam removal induce geomorphic channel

  11. Evaluating safety of concrete gravity dam on weak rock: Scott Dam

    International Nuclear Information System (INIS)

    Goodman, R.E.; Ahlgren, C.S.

    2000-01-01

    Scott Dam is owned and operated by Pacific Gas and Electric Co. (PG and E) as part of the Potter Valley Project. Although it is an unimpressive concrete gravity dam [233 m (765 ft) long with maximum water surface 33.4 m (110 ft) above tail water], the dam has unusually complex and weak foundation rocks; thick condition caused design changes during construction, numerous subsequent special investigations, and several corrections and additions. A main stumbling block to clarification of the dam safety issue for Scott Dam has always been difficulty in characterizing the foundation material. This paper discusses an approach to this problem as well s how the safety of the dam was subsequently confirmed. Following a comprehensive program of research, investigations, and analysis from 1991 to 1997

  12. A novel underwater dam crack detection and classification approach based on sonar images

    Science.gov (United States)

    Shi, Pengfei; Fan, Xinnan; Ni, Jianjun; Khan, Zubair; Li, Min

    2017-01-01

    Underwater dam crack detection and classification based on sonar images is a challenging task because underwater environments are complex and because cracks are quite random and diverse in nature. Furthermore, obtainable sonar images are of low resolution. To address these problems, a novel underwater dam crack detection and classification approach based on sonar imagery is proposed. First, the sonar images are divided into image blocks. Second, a clustering analysis of a 3-D feature space is used to obtain the crack fragments. Third, the crack fragments are connected using an improved tensor voting method. Fourth, a minimum spanning tree is used to obtain the crack curve. Finally, an improved evidence theory combined with fuzzy rule reasoning is proposed to classify the cracks. Experimental results show that the proposed approach is able to detect underwater dam cracks and classify them accurately and effectively under complex underwater environments. PMID:28640925

  13. Efeito de diferentes substratos sobre o desenvolvimento de mudas de Acacia sp. Effect of different substrates on the development of Acacia sp. seedlings

    Directory of Open Access Journals (Sweden)

    Alexson de Mello Cunha

    2006-04-01

    Full Text Available Os biossólidos têm sido estudados como fonte de matéria orgânica na agricultura. Objetivou-se avaliar o desenvolvimento de mudas de Acacia mangium e Acacia auriculiformis em diferentes substratos: a horizonte Bw com areia lavada (1:1, v:v e adubação mineral de 160, 640 e 160 g m-3de N, P2O5 e K2O, respectivamente (HB; b horizonte Bw com areia lavada e esterco bovino (1:1:1, v:v (HBE; c horizonte Bw com areia lavada e lodo de esgoto (1:1:1, v:v (HBL; e d 100% de lodo de esgoto (LE. Aplicou-se 1 kg de CaCO3 p.a. por m³ de substrato. Foram utilizadas sementes inoculadas com rizóbio e não-inoculadas, determinando-se, aos 90 dias após a semeadura, a altura das plantas, o diâmetro do colo e o peso da matéria seca da raiz e da parte aérea, na qual se determinaram N, P, K, Ca e Mg. O delineamento estatístico foi inteiramente casualizado, no esquema fatorial 2 x 4 (com ou sem inoculação x 4 substratos. No LE com inoculação, obteve-se melhor crescimento das mudas. O HBE produziu efeito superior no desenvolvimento das mudas em relação àquele com a mesma proporção de material orgânico na forma de lodo (HBL. Na maioria dos parâmetros avaliados não houve diferença devido à inoculação dos substratos HBE, HBL e HB, provavelmente devido à existência de bactérias nativas nesses substratos. As mudas desenvolvidas no substrato LE foram as que acumularam mais N e Ca, principalmente quando inoculadas. Houve tendência de maior acúmulo de P, K e Mg na parte aérea das mudas desenvolvidas no substrato HBE.Sewage sludge has been studied as source of organic matter on seedling production. Thus, this study aimed to evaluate the development of Acacia mangium and Acacia auriculiformis seedlings in the following substrates: a oxic horizon + sand (1:1, v:v + 160, 640 e 160 g m-3 of N, P2O5 and K2O respectively (HB; b oxic horizon + sand + cattle manure (1:1:1, v:v (HBE; c oxic horizon + sand + sewage sludge (1:1:1, v:v (HBL and; d 100% sewage

  14. Biologia reprodutiva de Acacia mearnsii de wild. (Fabaceae IV: visitantes florais Reproductive biology of Acacia mearnsii de wild. (Fabaceae IV: flower visitors

    Directory of Open Access Journals (Sweden)

    Eudes Maria Stiehl Alves

    2009-06-01

    Full Text Available Para que as estratégias de melhoramento genético em espécies arbóreas tenham sucesso, o conhecimento da biologia reprodutiva da espécie envolvida é indispensável. Um dos fatores críticos ao sucesso reprodutivo das espécies do gênero Acacia é a presença de vetores para a polinização. Os objetivos deste trabalho foram identificar os visitantes florais em um plantio comercial de Acacia mearnsii De Wild. e quantificar as políades aderidas à superfície corporal dos insetos. As observações foram realizadas em uma torre localizada no plantio comercial durante o período de floração de 2002 e 2003. Os visitantes florais foram capturados no período diurno com o auxílio de rede entomológica e de um cesto aéreo instalado em um trator. No período noturno, os insetos foram capturados com o auxílio de armadilhas luminosas instaladas entre as copas florescidas. Foram observados insetos pertencentes às ordens Coleoptera, Hymenoptera, Diptera, Hemiptera e Lepidoptera. Os besouros da espécie Macrodactylus suturalis foram considerados como dispersores do pólen de acácia-negra, pela alta frequência de indivíduos presentes no povoamento estudado e pela grande quantidade de políades aderidas no corpo dos insetos capturados (X=229,36 políades/inseto. As abelhas da espécie Apis mellifera, embora tenha sido quantificada uma grande quantidade de políades nos indivíduos capturados (X=448,50 políades/inseto, não foram observadas com frequência na área analisada. Uma das formas recomendadas para aumentar a frequência de abelhas e vespas nos plantios comerciais de acácia-negra é a manutenção de fontes de néctar e a introdução de caixas com abelhas A. mellifera.To ensure the success of the strategies of genetic improvement in tree species, knowledge of the reproductive biology of the species involved is essential. One of these critical factors in reproductive success of the genus Acacia is the presence of vectors to

  15. Establishment and implementation of a dam safety program

    International Nuclear Information System (INIS)

    Rogers, R.

    1993-01-01

    The reasons for implementing dam safety programs are discussed, and a model for a dam safety program is outlined. A dam safety program should consist of regular inspections, reservoir monitoring, an emergency action plan, remedial work, registration permit reports, routine maintenance, and careful water supply management. Recommendations on initiating and implementing a dam safety program include: communication with the appropriate regulatory authority; communication with maintenance crews; communication with management; a well-rounded dam inspection team; the inclusion of maintenance items in dam modification projects; visual inspection of the dam; monitoring key indicators such as monuments and piezometer readings; and keeping current with the literature. 4 refs

  16. Dam regulation and riverine food-web structure in a Mediterranean river.

    Science.gov (United States)

    Mor, Jordi-René; Ruhí, Albert; Tornés, Elisabet; Valcárcel, Héctor; Muñoz, Isabel; Sabater, Sergi

    2018-06-01

    Flow regimes are a major driver of community composition and structure in riverine ecosystems, and flow regulation by dams often induces artificially-stable flow regimes downstream. This represents a major source of hydrological alteration, particularly in regions where biota is adapted to strong seasonal and interannual flow variability. We hypothesized that dam-induced hydrological stability should increase the availability of autochthonous resources at the base of the food web. This, in turn, should favour herbivorous over detritivorous strategies, increasing the diversity of primary consumers, and the food-web width and length. We tested this hypothesis by studying the longitudinal variation in food-web structure in a highly-seasonal Mediterranean river affected by an irrigation dam. We compared an unregulated reach to several reaches downstream of the dam. Hydrological and sedimentological stability increased downstream of the dam, and altered the type and quantity of available resources downstream, prompting a change from a detritus-based to an algae-based food web. The fraction of links between top and intermediate species also increased, and the food web became longer and wider at the intermediate trophic levels. Food-web structure did not recover 14km downstream of the dam, despite a partial restitution of the flow regime. Our results advance the notion that hydrologic alteration affects riverine food webs via additions/deletions of taxa and variation in the strength and distribution of food-web interactions. Thus, flow regulation by dams may not only impact individual facets of biodiversity, but also food-web level properties across river networks. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Mystery of Mosul Dam the Most Dangerous Dam in the World:Karstification and Sinkholes

    OpenAIRE

    Al-Ansari, Nadhir; Adamo, Nasrat; Issa, Issa; Sissakian, Varoujan; Knutsson, Sven

    2015-01-01

    The Fatha (ex-Lower Fars) Formation (Middle Miocene) is the predominant stratigraphic unit in the Mosul Dam area. It is about 250 meters thick near Mosul. Marls, chalky limestone, gypsum, anhydrite, and limestone form a layered sequence of rocks under the foundation of the dam. The foundation of the dam is mainly resting on the Fatha Formation (Middle Miocene) which is highly karstified. Karstic limestone and the development of solution cavities within the gypsum and anhydrite layers are the ...

  18. Tannins from Acacia mearnsii De Wild. Bark: Tannin Determination and Biological Activities

    Directory of Open Access Journals (Sweden)

    Sosuke Ogawa

    2018-04-01

    Full Text Available The bark of Acacia mearnsii De Wild. (black wattle contains significant amounts of water-soluble components acalled “wattle tannin”. Following the discovery of its strong antioxidant activity, a wattle tannin dietary supplement has been developed and as part of developing new dietary supplements, a literature search was conducted using the SciFinder data base for “Acacia species and their biological activities”. An analysis of the references found indicated that the name of Acacia nilotica had been changed to Vachellia nilotica, even though the name of the genus Acacia originated from its original name. This review briefly describes why and how the name of A. nilotica changed. Tannin has been analyzed using the Stiasny method when the tannin is used to make adhesives and the hide-powder method is used when the tannin is to be used for leather tanning. A simple UV method is also able to be used to estimate the values for both adhesives and leather tanning applications. The tannin content in bark can also be estimated using NIR and NMR. Tannin content estimations using pyrolysis/GC, electrospray mass spectrometry and quantitative 31P-NMR analyses have also been described. Tannins consists mostly of polyflavanoids and all the compounds isolated have been updated. Antioxidant activities of the tannin relating to anti-tumor properties, the viability of human neuroblastoma SH-SY5Y cells and also anti-hypertensive effects have been studied. The antioxidant activity of proanthocyanidins was found to be higher than that of flavan-3-ol monomers. A total of fourteen papers and two patents reported the antimicrobial activities of wattle tannin. Bacteria were more susceptible to the tannins than the fungal strains tested. Several bacteria were inhibited by the extract from A. mearnsii bark. The growth inhibition mechanisms of E. coli were investigated. An interaction between extracts from A. mearnsii bark and antibiotics has also been studied. The

  19. Tannins from Acacia mearnsii De Wild. Bark: Tannin Determination and Biological Activities.

    Science.gov (United States)

    Ogawa, Sosuke; Yazaki, Yoshikazu

    2018-04-05

    The bark of Acacia mearnsii De Wild. (black wattle) contains significant amounts of water-soluble components acalled "wattle tannin". Following the discovery of its strong antioxidant activity, a wattle tannin dietary supplement has been developed and as part of developing new dietary supplements, a literature search was conducted using the SciFinder data base for " Acacia species and their biological activities". An analysis of the references found indicated that the name of Acacia nilotica had been changed to Vachellia nilotica , even though the name of the genus Acacia originated from its original name. This review briefly describes why and how the name of A. nilotica changed. Tannin has been analyzed using the Stiasny method when the tannin is used to make adhesives and the hide-powder method is used when the tannin is to be used for leather tanning. A simple UV method is also able to be used to estimate the values for both adhesives and leather tanning applications. The tannin content in bark can also be estimated using NIR and NMR. Tannin content estimations using pyrolysis/GC, electrospray mass spectrometry and quantitative 31 P-NMR analyses have also been described. Tannins consists mostly of polyflavanoids and all the compounds isolated have been updated. Antioxidant activities of the tannin relating to anti-tumor properties, the viability of human neuroblastoma SH-SY5Y cells and also anti-hypertensive effects have been studied. The antioxidant activity of proanthocyanidins was found to be higher than that of flavan-3-ol monomers. A total of fourteen papers and two patents reported the antimicrobial activities of wattle tannin. Bacteria were more susceptible to the tannins than the fungal strains tested. Several bacteria were inhibited by the extract from A. mearnsii bark. The growth inhibition mechanisms of E. coli were investigated. An interaction between extracts from A. mearnsii bark and antibiotics has also been studied. The extracts from A. mearnsii

  20. Dam break analysis and flood inundation map of Krisak dam for emergency action plan

    Science.gov (United States)

    Juliastuti, Setyandito, Oki

    2017-11-01

    The Indonesian Regulation which refers to the ICOLD Regulation (International Committee on Large Dam required have the Emergency Action Plan (EAP) guidelines because of the dams have potential failure. In EAP guidelines there is a management of evacuation where the determination of the inundation map based on flood modeling. The purpose of the EAP is to minimize the risk of loss of life and property in downstream which caused by dam failure. This paper will describe about develop flood modeling and inundation map in Krisak dam using numerical methods through dam break analysis (DBA) using hydraulic model Zhong Xing HY-21. The approaches of dam failure simulation are overtopping and piping. Overtopping simulation based on quadrangular, triangular and trapezium fracture. Piping simulation based on cracks of orifice. Using results of DBA, hazard classification of Krisak dam is very high. The nearest village affected dam failure is Singodutan village (distance is 1.45 kilometer from dam) with inundation depth is 1.85 meter. This result can be used by stakeholders such as emergency responders and the community at risk in formulating evacuation procedure.

  1. 76 FR 34799 - Permanent Dam Safety Modification at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams, TN

    Science.gov (United States)

    2011-06-14

    ... TENNESSEE VALLEY AUTHORITY Permanent Dam Safety Modification at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams, TN AGENCY: Tennessee Valley Authority. ACTION: Notice of intent. SUMMARY: This... existing dam facilities at Cherokee, Fort Loudoun, Tellico, and Watts Bar dams in Tennessee. The level of...

  2. 33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. 208.19 Section 208.19 Navigation and Navigable Waters... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. The Secretary of the...

  3. Industrial design of an earth overflow dam

    Energy Technology Data Exchange (ETDEWEB)

    Pravdivets, Yu.P.

    1988-06-01

    As a result of theoretical and experimental investigations of earth overflow dams of various types and purpose conducted by the author in the past ten years, methods of calculating the stability of protective structures of riprap, reinforcement meshes, gabions, and in situ and precast reinforced concrete were substantiated; the limits of economic applicability of various types of revetments and structures were determined; and new efficient designs of dams and revetments allowing the overflow of water with large discharge intensities were proposed. An earth overflow dam with the downstream slope protected by a precast reinforced-concrete revetment was determined to be the most effective design-technological solution. Both the entire dam or a part of it can be made overflow. The design has been realized on a number of experimental water-management objects which are reviewed.

  4. Dams life; La vie des barrages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This paper summarizes the conclusions of the annual inspections of French dams in operation (fissures, water oozing, concrete swelling etc..). Only the observations which require a special attention are reported. (J.S.)

  5. Biological - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  6. Physical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  7. Seismic risks at Elsie Lake Main Dam

    International Nuclear Information System (INIS)

    McCammon, N.R.; Momenzadeh, M.; Hawson, H.H.; Nielsen, N.M.

    1991-01-01

    The Elsie Lake dams are located on Vancouver Island in an area of high seismic risk. A safety review in 1986 indicated potential deficiencies in the earthfill main dam with respect to modern earthquake design standards. A detailed field investigation program comprising drilling and penetration tests was carried out and the results used in an assessment of seismic stability. A 0.8 m thick less dense layer in the granular shell of the dam, possibly caused by wet construction conditions, would likely liquefy in a major earthquake but sufficient residual strength would likely remain to prevent catastrophic failure. The dam shell might undergo some distortion, and an assessment was initiated to determine the requirements for reservoir drawdown following an extreme earthquake to ensure the timely lowering of the reservoir for inspection and repair. It was suggested that an adequate evacuation capability would be 25% and 50% drawdown in not more than 30 and 50 days, respectively. 9 refs., 11 figs., 1 tab

  8. COMPARATIVE STUDY REGARDING THE QUANTITY OF ACACIA AND LIME HONEY HARVESTED IN 2008 IN VARIOUS TYPES OF BEEHIVES

    Directory of Open Access Journals (Sweden)

    SILVIA PĂTRUICĂ

    2009-10-01

    Full Text Available The paperwork present the results of a comparative study regarding the production of acacia (Robinia pseudacacia and lime honey harvested in 2008 in flat, vertical and multi-frame hives. A total of 45 bee families (Apis mellifica carpatica, Banatica ecotipe, divided in three experimental groups, with 15 families on each hive, were examined for every type of hive. During the experiment there were tracked the number of honeycombs with larvae starting from 7th to 10th of April and from 1st to 5th of May, the acacia and lime honey yield.

  9. Silage Quality of King Grass (Pennisetum purpureophoides Treated with Epiphytic Lactic Acid Bacteria and Tannin of Acacia

    Directory of Open Access Journals (Sweden)

    B. Santoso

    2011-08-01

    Full Text Available The aim of this study was to evaluate the silage quality of king grass (Pennisetum purpureophoides treated with addition of epiphytic lactic acid bacteria (LAB prepared from fermented grass extract (FGE or combined with tannin of acacia. Experiment was arranged to a completely randomized design with six treatments and three replications. Treatments were (A king grass without additive as a control; (B king grass + 3% (v/w of FGE; (C king grass + 3% (v/w of FGE + 10 ml of acacia extract (50 g/100 ml; (D king grass + 3% of FGE (v/w + 10 ml of acacia extract (50 g/75 ml; (E king grass + 3% of FGE (v/w + 10 ml of acacia extract (50 g/50 ml, and (F king grass + 3% of FGE (v/w + 10 ml of acacia extract (50 g/25 ml. About 250 g of silage materials were ensiled in 400 ml bottle silos at room temperatures (approximately 28 °C for 30 days. Variables measured were characteristics of FGE, fermentation characteristics and chemical composition of silage. Data were analyzed by analysis of variance and the significance differences among means were tested by the Duncan’s multiple range test. Results showed that the number of lactic acid bacteria in FGE increased from 0.8 × 107 cfu/ml to 2.9 × 107 cfu/ml after 2 days anaerobic incubation. Concentration of lactic acid in silages with addition of FGE or combined with tannin of acacia (B, C, D, E, and F were higher (P<0.01 than that of silage A (control. Silages with addition of FGE combined with tannin of acacia (C, D, E, and F had lower pH value than that of silages A and B. Concentrations of NH3-N decreased with increasing concentration of tannin. Butyric acid concentration decreased in silages B, C, D, E, and F as compared to that in silage A. Addition of FGE combined with tannin prepared from acacia leaf improved fermentation quality of king grass silage.

  10. PERBANDINGAN VIGORITAS BENIH Acacia mangium HASIL PEMULIAAN DAN YANG BELUM DIMULIAKAN

    Directory of Open Access Journals (Sweden)

    Naning Yuniarti

    2014-04-01

    Full Text Available Seeds with high vigour are seeds that can germinate normally in sub-optimum conditions and above normal in optimum condition. To predict the performance of seedlings after planting and the storability of seeds, it is necessary to test the seed vigour. This study aims to investigate the growth and storage vigour of Acacia mangium breeding and unbreeding seeds. The experiment design was arranged in completely randomized design with each treatment being replicated four times with 100 seeds. Results obtained showed that breeding seeds had better growth and storage vigour. 

  11. Karakteristik Spektra Absorbansi NIR (Near Infra Red Spektroskopi Kayu Acacia mangium WILLD pada 3 Umur Berbeda

    Directory of Open Access Journals (Sweden)

    Lina Karlinasari

    2014-01-01

    Full Text Available Penelitian mengenai pengujian nondestruktif metode near infrared (NIR spektroskopi di Indonesia masih sangat terbatas. Penelitian ini bertujuan untuk menentukan karakteristik spektra NIR spektroskopi (panjang gelombang 700 nm – 2500 nm kayu Acacia mangium dari 3 umur yaitu 5, 6, dan, 7 tahun. Kayu mangium diperoleh dari daerah Maribaya, Parung Panjang, Bogor. Sampel contoh uji spektra terdiri dari bentuk solid atau padatan dan bentuk serbuk kayu. Hasil penelitian menunjukkan spektra absorban NIR sampel padatan kayu lebih tinggi dibandingkan bentuk sampel serbuk. Umur pohon untuk jenis kayu yang sama tidak memberikan informasi perbedaan pola spektra absorbansi NIR yang nyata untuk setiap lokasi panjang gelombangnya. Penelitian lebih lanjut dapat dilakukan untuk menentukan model pendugaan sifat kimia, fisis dan mekanis kayu menggunakan analisis statistik metode analisis multivariasi. Kata kunci: NIR spektroskopi, Acacia mangium, kayu solid, serbuk kayu    Characteristics of Absorbency Spectra of NIR (Near Infra Red Spectroscopy of Acacia mangium Willd Wood from Three Different Age Abstract Research on non-destructive test of near infrared (NIR spectroscopy method was still limited in Indonesia. The aim of this study was to determine near infrared (NIR spectroscopy (wavelength range within 780 nm -2500 nm characteristic of wood species of Acacia mangium. The samples were selected from three different ages e.g. 5 year, 6 years, and 7 years grown in Maribaya area of Parung Panjang Distric. The NIR testing samples used were solid wood and ground wood. This study resulted that there was visually no significant difference of absorbance spectra NIR patterns based on wood ages. NIR absorbance spectra had same trend for both solid and ground wood samples in a range of wavelength, although those were in different values. The NIR absorbance spectra values of solid wood samples seemed higher than ground wood samples. Further research is needed to

  12. Incidences and severity of vascular wilt in Acacia mangium plantations in Sabah, Malaysia

    Science.gov (United States)

    Maid, Mandy; Ratnam, Wickneswari

    2014-09-01

    This study aimed to evaluate the incidences and severity of vascular wilt disease associated with dieback in stands of commercial Acacia mangium plantations. The study revealed that the prevalence of the symptoms is high between 50 to 60% in two plantations, where it is found scattered in the plots that were surveyed. The incidence of the disease in each plot is low between 0 to 6%. The disease symptoms were more often found where the symptom syndrome in a chronic (level 3) or critical state (level 4). This suggests that the causal pathogen has the ability to penetrate into the tissues of the plants and only display symptoms at the latest stage.

  13. Analisa Parameter Genetik Sifat Kayu Kombinasi Uji Provenans Dan Uji Keturunan Acacia Mangium Di Kalimantan Selatan

    OpenAIRE

    Susanto, Mudji; Na'iem, Muhammad; Hardiyanto, Eko Bhakti; Prayitno, T.A

    2012-01-01

    Combination of provenance progeny trial of Acacia mangium from Claudie River-Queensland- Australia was established in Pelaihari, South Kalimantan. The objective of this research is to find variation on diameter, wood specific gravity and fiber lenght between provenance seedlot and family within provenance seedlot in provenance progeny trial of A. mangium on 22 months old.The results showed that the mean of wood specific gravity and was 0.40 and mean of fiber length was 0.89 mm. Variation of d...

  14. Keawetan Kayu Tusam (Pinus Merkusii Jungh. Et De Vr.) dan Mangium (Acacia Mangium Willd.) Setelah Furfurilasi

    OpenAIRE

    Balfas, Jamal; Sumarni, Ginuk

    1995-01-01

    Two regrowth wood species, i.e. tusam (Pinus merkusii Jungh. et de Vr.) and mangium (Acacia mangium Wild.) were used in this study. Specimens measuring 25 mm x 25 mm x 50 mm and 5 mm x 25 mm x 25 mm were prepared for testing against dry-wood termite (Cryptotermes) and subteranean termite (Coptotermes) respectively. All specimens were air-dried to approxi mately 16-18% moisture content. One group of the specimens was further oven - dried to reach moisture content of 6-8%. Furfurylation ...

  15. Avaliação de mutualismo entre acacia mangium wild (Mimosaceae) e formigas (Hymenoptera: Formicidae).

    OpenAIRE

    Bertuol, Tiago José; Galbiati, Carla; Pereira, Mônica Josene Barbosa; Amaral, Anderson Marques do

    2008-01-01

    O mutualismo entre formigas e plantas consiste na proteção da árvore pela formigas contra herbívoros, que recebem em troca alimento ou local para nidificação. O objetivo desta pesquisa foi verificar a relação entre Acacia mangium Willd e formigas visitantes. O estudo foi realizado em Cáceres, MT, em 14 plantas de A. mangium escolhidas ao acaso em um sistema agroflorestal. Em cada planta foi mensurada a área foliar consumida por herbívoros através de um gabarito, em quatro folhas/planta. A agr...

  16. RESEARCHES CONCERNING OF THE MINERAL CONTENT OF ACACIA HONEY DERIVED ON DIFFERENTS COUNTRY

    Directory of Open Access Journals (Sweden)

    SILVIA PĂTRUICĂ

    2008-10-01

    Full Text Available The paper presents the results of the research concerning chemical composition of acacia honey from the differents region. Analisys concerning the mineral content were made in 14-19 march 2008 in the molecular and atomical spectroscopy laboratoriy of the Faculty of Agro-Food Tehnology and Processing from USABMV Timisoara, through spectroscopy with atomic absorbability in flame with the spectrometer. Contr AA 300 with continous surce. There were anailzted 3 honey samples made in 2007 from Domasnea and Farliug (Caras-Severin and Bala (Mehedinti. The ash contain in Na, K, Ca, Mg, Cu, Zn, Mn, Fe, Pb, Co, Cr was determined.

  17. Expectations of immortality: dam safety management into the next millennium

    International Nuclear Information System (INIS)

    Palmer, M.D.

    1999-01-01

    Topics concerning the problems associated with older and aging dams are considered including: what can be done to extent the lifetime of an old dam, the decision to decommission a dam based on a value judgment that the risk of maintaining the dam is too great for society's acceptance, the possibility of change in the level of risk tolerance with time in a technological environment, traditional surveillance methods used by dam owners in the Y2K situation, and the unreality of dam immortality. Trends and means for preserving older dams for their owner's purposes are outlined, as well as their lifetime compared to that of the downstream systems they serve. Despite the fact that we live in a throwaway society, dam owners cannot just leave their dam asset when they are through with using it. Someone has to maintain the dam, or ensure that it is safely decommissioned when the owner is finished with it. On a worldwide scale the available pool of experienced dam engineers is shrinking. This problem needs to be addressed by a shift towards operating and dam safety management skills based on a firm awareness of dam design principles. A shift in society's expectations has occurred such that dam designers and owners must now recognize the impact a dam can have both on its natural and social environments. Because of the increasing emphasis on paying attention to the impacts of people's activities on the planet, engineers more than anyone else must have a significant influence in that direction. 9 refs

  18. Walter Bouldin Dam failure and reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-09-01

    Walter Bouldin is one of several hydroelectric developments of Alabama Power Company. On February 10, 1975, an earth embankment section of Walter Bouldin Dam was breached, causing total evacuation of the forebay reservoir and rendering the 225-MW power plant inoperable. The Federal Power Commission instituted an investigation of the dam failure, and a report on the investigation was published in February 1976. Subsequently, an evidentiary hearing was held before an administrative law judge who issued his initial decision on August 19, 1976. The Commission, on April 21, 1977, issued its Opinion No. 795 in which it adopted the initial decision with modifications and terminated the investigation of failure of Walter Bouldin Dam. Opinion No. 795 directs the staff of the Bureau of Power to prepare, for the future guidance of the Commission, a report on the deficiencies which were found in its investigation, together with advice as to how such deficiencies have been and should be remedied. Also, it directs the staff of the Bureau of Power to address certain general recommendations included in the initial decision. This report was prepared in response to that directive and summaries information on the dam failure and its investigation; the evidentiary hearing; the judge's recommendations, the reconstruction of the Bouldin Dam; and the evalution and status of the Federal Energy Regulatory Commission Dam safety program. (LCL)

  19. Application of a hierarchical framework for assessing environmental impacts of dam operation: changes in hydrology, channel hydraulics, bed mobility and recruitment of riparian trees in a western North American river

    Science.gov (United States)

    Michael Burke; Klaus Jorde; John M. Buffington

    2009-01-01

    River systems have been altered worldwide by dams and diversions, resulting in a broad array of environmental impacts. The use of a process-based, hierarchical framework for assessing environmental impacts of dams is explored here in terms of a case study of the Kootenai River, western North America. The goal of the case study is to isolate and quantify the relative...

  20. Digging, Damming or Diverting? Small-Scale Irrigation in the Blue Nile Basin, Ethiopia

    Directory of Open Access Journals (Sweden)

    Irit Eguavoen

    2012-10-01

    Full Text Available The diversity of small-scale irrigation in the Ethiopian Blue Nile basin comprises small dams, wells, ponds and river diversion. The diversity of irrigation infrastructure is partly a consequence of the topographic heterogeneity of the Fogera plains. Despite similar social-political conditions and the same administrative framework, irrigation facilities are established, used and managed differently, ranging from informal arrangements of households and 'water fathers' to water user associations, as well as from open access to irrigation schedules. Fogera belongs to Ethiopian landscapes that will soon transform as a consequence of large dams and huge irrigation schemes. Property rights to land and water are negotiated among a variety of old and new actors. This study, based on ethnographic, hydrological and survey data, synthesises four case studies to analyse the current state of small-scale irrigation. It argues that all water storage options have not only certain comparative advantages but also social constraints, and supports a policy of extending water storage 'systems' that combine and build on complementarities of different storage types instead of fully replacing diversity by large dams.

  1. Simulating dam - breach flood scenarios of the Tangjiashan landslide dam induced by the Wenchuan earthquake

    NARCIS (Netherlands)

    Fan, Xuanmei; Tang, C.; van Westen, C.J.; Alkema, D.

    2012-01-01

    Floods from failures of landslide dams can pose a hazard to people and property downstream, which have to be rapidly assessed and mitigated in order to reduce the potential risk. The Tangjiashan landslide dam induced by the Mw=7.9 2008 Wenchuan earthquake had impounded the largest lake in the

  2. the effect of age of dam on weaning mass for ftve dam breed types

    African Journals Online (AJOL)

    SUMMARY: The effect of age of dam on adjusted 210 day calf weaning mass was estimated by the Least Squares method for 5 dam types on 2 farms. ... the later maturing breeds would have a low level of productivity because these cows would be eliminated in their potentially prime .... time at 28 (2A) or 3l (28) months old.

  3. The remains of the dam: what have we learned from 15 years of US dam removals?

    Science.gov (United States)

    Gordon E. Grant; Sarah L. Lewis

    2015-01-01

    Important goals for studying dam removal are to learn how rivers respond to large and rapid introductions of sediment, and to develop predictive models to guide future dam removals. Achieving these goals requires organizing case histories systematically so that underlying physical mechanisms determining rates and styles of sediment erosion, transport, and deposition...

  4. The interplay of activists and dam developers : the case of Myanmar’s mega-dams

    NARCIS (Netherlands)

    Kirchherr, Julian; J. Charles, Katrina; Walton, Matthew J.

    2017-01-01

    Scholars investigating activism against large dam developments in Asia usually focus on those campaigning, but not on those the campaigns are aimed at–the dam developers. Yet the developers’ perspective is crucial to comprehensively understand the dynamics of social and environmental activism in

  5. Dam that social networking: connecting South Africa's major dams to social media

    CSIR Research Space (South Africa)

    Butgereit, L

    2011-10-01

    Full Text Available where four major South African dams are connected to Twitter and Facebook (and other social media such as MXit and Google Chat) in a mechanism which would be easy to replicate for additional dams or rivers. Data is supplied by the South African...

  6. Host-driven diversification of gall-inducing Acacia thrips and the aridification of Australia

    Directory of Open Access Journals (Sweden)

    Chapman Thomas W

    2007-01-01

    Full Text Available Abstract Background Insects that feed on plants contribute greatly to the generation of biodiversity. Hypotheses explaining rate increases in phytophagous insect diversification and mechanisms driving speciation in such specialists remain vexing despite considerable attention. The proliferation of plant-feeding insects and their hosts are expected to broadly parallel one another where climate change over geological timescales imposes consequences for the diversification of flora and fauna via habitat modification. This work uses a phylogenetic approach to investigate the premise that the aridification of Australia, and subsequent expansion and modification of arid-adapted host flora, has implications for the diversification of insects that specialise on them. Results Likelihood ratio tests indicated the possibility of hard molecular polytomies within two co-radiating gall-inducing species complexes specialising on the same set of host species. Significant tree asymmetry is indicated at a branch adjacent to an inferred transition to a Plurinerves ancestral host species. Lineage by time diversification plots indicate gall-thrips that specialise on Plurinerves hosts differentially experienced an explosive period of speciation contemporaneous with climatic cycling during the Quaternary period. Chronological analyses indicated that the approximate age of origin of gall-inducing thrips on Acacia might be as recent as 10 million years ago during the Miocene, as truly arid landscapes first developed in Australia. Conclusion Host-plant diversification and spatial heterogeneity of hosts have increased the potential for specialisation, resource partitioning, and unoccupied ecological niche availability for gall-thrips on Australian Acacia.

  7. Growth and nitrogen acquisition strategies of Acacia senegal seedlings under exponential phosphorus additions.

    Science.gov (United States)

    Isaac, M E; Harmand, J M; Drevon, J J

    2011-05-15

    There remains conflicting evidence on the relationship between P supply and biological N(2)-fixation rates, particularly N(2)-fixing plant adaptive strategies under P limitation. This is important, as edaphic conditions inherent to many economically and ecologically important semi-arid leguminous tree species, such as Acacia senegal, are P deficient. Our research objective was to verify N acquisition strategies under phosphorus limitations using isotopic techniques. Acacia senegal var. senegal was cultivated in sand culture with three levels of exponentially supplied phosphorus [low (200 μmol of P seedling(-1) over 12 weeks), mid (400 μmol) and high (600 μmol)] to achieve steady-state nutrition over the growth period. Uniform additions of N were also supplied. Plant growth and nutrition were evaluated. Seedlings exhibited significantly greater total biomass under high P supply compared to low P supply. Both P and N content significantly increased with increasing P supply. Similarly, N derived from solution increased with elevated P availability. However, both the number of nodules and the N derived from atmosphere, determined by the (15)N natural abundance method, did not increase along the P gradient. Phosphorus stimulated growth and increased mineral N uptake from solution without affecting the amount of N derived from the atmosphere. We conclude that, under non-limiting N conditions, A. senegal N acquisition strategies change with P supply, with less reliance on N(2)-fixation when the rhizosphere achieves a sufficient N uptake zone. Copyright © 2010 Elsevier GmbH. All rights reserved.

  8. Anatomical characters of the phyllode and stem of Acacia podalyriifolia A. Cunn. ex G. Don (Fabaceae

    Directory of Open Access Journals (Sweden)

    M.R. Duarte

    Full Text Available The Acacia genus has presented various secondary metabolites, such as tannins, flavonoids, alkaloids and gums. Preparations from different species have been applied for diabetes, gastrointestinal disorders and inflammatory diseases in the traditional medicine and have demonstrated cytotoxic, antimicrobial and antiparasitic activities. Acacia podalyriifolia A. Cunn. ex G. Don (Fabaceae is a small wood, indigenous to Australia and cultivated worldwide for its ornamental feature. This work aimed to characterize the anatomy of the phyllode and stem, in order to contribute to the species identification. The botanical material was fixed, sectioned and prepared according to usual light and scanning microtechniques. The epidermal cells, in surface view, are polygonal and coated with striate and thick cuticle, and filaments of epicuticular wax. Paracytic stomata and unicellular non-glandular trichomes are seen. Palisade and ground parenchymas, and minor collateral bundles with xylem directed alternately to upper and lower sides occur in the blade. The midrib shows two collateral bundles facing each other. The stem, in incipient secondary growth, exhibits epidermis, annular collenchyma, sclerenchymatic sheath and collateral vascular organization. Cells containing phenolic compounds and prisms of calcium oxalate are observed.

  9. Gibberellin mediates the development of gelatinous fibres in the tension wood of inclined Acacia mangium seedlings.

    Science.gov (United States)

    Nugroho, Widyanto Dwi; Nakaba, Satoshi; Yamagishi, Yusuke; Begum, Shahanara; Marsoem, Sri Nugroho; Ko, Jae-Heung; Jin, Hyun-O; Funada, Ryo

    2013-11-01

    Gibberellin stimulates negative gravitropism and the formation of tension wood in tilted Acacia mangium seedlings, while inhibitors of gibberellin synthesis strongly inhibit the return to vertical growth and suppress the formation of tension wood. To characterize the role of gibberellin in tension wood formation and gravitropism, this study investigated the role of gibberellin in the development of gelatinous fibres and in the changes in anatomical characteristics of woody elements in Acacia mangium seedlings exposed to a gravitational stimulus. Gibberellin, paclobutrazol and uniconazole-P were applied to the soil in which seedlings were growing, using distilled water as the control. Three days after the start of treatment, seedlings were inclined at 45 ° to the vertical and samples were harvested 2 months later. The effects of the treatments on wood fibres, vessel elements and ray parenchyma cells were analysed in tension wood in the upper part of inclined stems and in the opposite wood on the lower side of inclined stems. Application of paclobutrazol or uniconazole-P inhibited the increase in the thickness of gelatinous layers and prevented the elongation of gelatinous fibres in the tension wood of inclined stems. By contrast, gibberellin stimulated the elongation of these fibres. Application of gibberellin and inhibitors of gibberellin biosynthesis had only minor effects on the anatomical characteristics of vessel and ray parenchyma cells. The results suggest that gibberellin is important for the development of gelatinous fibres in the tension wood of A. mangium seedlings and therefore in gravitropism.

  10. Physico-mechanical properties of plywood bonded with ecological adhesives from Acacia mollissima tannins and lignosulfonates

    Science.gov (United States)

    Rhazi, Naima; Oumam, Mina; Sesbou, Abdessadek; Hannache, Hassan; Charrier-El Bouhtoury, Fatima

    2017-06-01

    The objective of this research was to develop ecological adhesives for bonding plywood panels using lignosulfonates, a common waste product of the wood pulp industry, and natural tannin extracted from Moroccan bark of Acacia mollissima using different process. Natural tannin and lignin were used in wood adhesives formulation to substitute resins based on phenol and formaldehyde. To achieve this, the lignosulfonates were glyoxalated to enhance their reactivity and the used tannins obtained by three different extraction methods were compared with commercial mimosa tannin. The proportion of Acacia mollissima tannins and lignosulfonates, the pressing time, the pressing temperature, and the pressure used were studied to improve mechanical properties, and bonding quality of plywood panel. The properties of plywood panels produced with these adhesives were tested in accordance with normative tests. Thus, the tensile strength, and the shear strength were measured. The results showed that the performance of the plywood panels made using biobased tannin adhesives was influenced by physical conditions such as pressure, press temperature as well as by chemical conditions, such as the tannin-lignin ratio. It exhibited excellent mechanical properties comparable to commercially available phenol-formaldehyde plywood adhesives. This study showed that biobased adhesives formulations presented good and higher mechanical performance and no formaldehyde emission. Contribution to the topical issue "Materials for Energy harvesting, conversion and storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  11. Economic assessment and comparison of acacia energy crop with annual traditional crops in Southern Europe

    International Nuclear Information System (INIS)

    Gasol, Carles M.; Rieradevall, Joan; Gabarrell, Xavier; Brun, Filippo; Mosso, Angela

    2010-01-01

    In several policy documents bioenergy is recognized as an important renewable energy source in Italy. The increase in energy prices represents an opportunity for lignocellulosic energy crops such as acacia and poplar. However, for Short Rotation Coppice (SRC) and Short Rotation Forestry (SRF) to be adopted by farmers, these crops must be perceived to be at least as profitable as crops that normally compete with these plantations for land use. The purpose of this paper is to evaluate the economic feasibility of acacia (Robinia pseudoacacia) as an energy crop in a low input production regime in Italy and, in particular, to consider its competitiveness with wheat. Our results show that neither SRC and SRF techniques using assumed production costs (EUR3820 and EUR5285 ha -1 yr -1 ) nor biomass productions are able to obtain a positive profit (-EUR184 and -EUR172 ha -1 yr -1 ) that can convince farmers to invest in biomass plantations on their land. The results demonstrate that wheat is a more economically secure option than SRC or SRF. The viability of local biomass production in Italy and Southern Europe depends on the active support of the governments; without them, biomass is not economically competitive for the farmers when compared to crops such as wheat. (author)

  12. Arsenic toxicity in Acacia mangium willd. and mimosa Caesalpiniaefolia benth. seedlings

    Directory of Open Access Journals (Sweden)

    Henrique Nery Cipriani

    2013-10-01

    Full Text Available Acacia mangium and Mimosa caesalpiniaefolia are fast-growing woody fabaceous species that might be suitable for phytoremediation of arsenic (As-contaminated sites. To date, few studies on their tolerance to As toxicity have been published. Therefore, this study assessed As toxicity symptoms in A. mangium and M. caesalpiniaefolia seedlings under As stress in a greenhouse. Seedlings of Acacia mangium and M. caesalpiniaefolia were grown for 120 d in an Oxisol-sand mixture with 0, 50, 100, 200, and 400 mg kg-1 As, in four replications in four randomized blocks. The plants were assessed for visible toxicity symptoms, dry matter production, shoot/root ratio, root anatomy and As uptake. Analyses of variance and regression showed that the growth of A. mangium and M. caesalpiniaefolia was severely hindered by As, with a reduction in dry matter production of more than 80 % at the highest As rate. The root/shoot ratio increased with increasing As rates. At a rate of 400 mg kg-1 As, whitish chlorosis appeared on Mimosa caesalpiniaefolia seedlings. The root anatomy of both species was altered, resulting in cell collapse, death of root buds and accumulation of phenolic compounds. Arsenic concentration was several times greater in roots than in shoots, with more than 150 and 350 mg kg-1 in M. caesalpiniaefolia and A. mangium roots, respectively. These species could be suitable for phytostabilization of As-contaminated sites, but growth-stimulating measures should be used.

  13. The Total Risk Analysis of Large Dams under Flood Hazards

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2018-02-01

    Full Text Available Dams and reservoirs are useful systems in water conservancy projects; however, they also pose a high-risk potential for large downstream areas. Flood, as the driving force of dam overtopping, is the main cause of dam failure. Dam floods and their risks are of interest to researchers and managers. In hydraulic engineering, there is a growing tendency to evaluate dam flood risk based on statistical and probabilistic methods that are unsuitable for the situations with rare historical data or low flood probability, so a more reasonable dam flood risk analysis method with fewer application restrictions is needed. Therefore, different from previous studies, this study develops a flood risk analysis method for large dams based on the concept of total risk factor (TRF used initially in dam seismic risk analysis. The proposed method is not affected by the adequacy of historical data or the low probability of flood and is capable of analyzing the dam structure influence, the flood vulnerability of the dam site, and downstream risk as well as estimating the TRF of each dam and assigning corresponding risk classes to each dam. Application to large dams in the Dadu River Basin, Southwestern China, demonstrates that the proposed method provides quick risk estimation and comparison, which can help local management officials perform more detailed dam safety evaluations for useful risk management information.

  14. Evolution of a Dammed River: Trajectories of Geomorphic Change on the Trinity River, CA

    Science.gov (United States)

    Curtis, J. A.; Guerrero, T. M.

    2012-12-01

    Historic landuse, dam construction (ca. 1964), water storage and flow diversion within the Trinity River watershed resulted in simplification of the river planform and dramatic losses in riparian habitat. The pre-dam Trinity River included a series of deep pools, active bar sequences, minor amounts of riparian vegetation, and an extensive floodplain. Dam construction and the export of ~ 75 to 90% of the average annual inflow at the top of the study reach lead to riparian encroachment, channel narrowing, stabilization of alluvial features, and a decline in coarse bed material. Following dam closure channel complexity decreased as bars were stabilized and coalesced into a system-wide post-dam topographic bench with an extensive riparian berm. Flow diversions further resulted in the abandonment of the pre-dam geomorphic floodplain and aggradation of tributary confluences due to dramatic reductions in flow competency and capacity. Beginning in 2001, the Trinity River Restoration Program (TRRP) implemented a combination of flow releases, gravel augmentation, bank rehabilitation, and watershed restoration to promote dynamic channel processes. The TRRP functions under an adaptive management framework which includes external peer review. In this regard the TRRP requested a geomorphic assessment of a 65-km restoration reach during pre- and post-restoration time periods which will be used to inform future restoration work. Building upon previous work at the site and reach scale we digitized a series of geomorphic maps and quantified the nature, extent and rates of geomorphic change during five post-dam time periods. Terrestrial and aquatic features were mapped using rectified orthophotography (1980, 1997, 2001, 2006, 2009, 2011) and the resultant data were used to determine trajectories of geomorphic change related to natural river processes and restoration actions. The series of geomorphic maps illustrate a system-wide perspective of evolving geomorphic features and

  15. Hydrogeophysical investigations at Hidden Dam, Raymond, California

    Science.gov (United States)

    Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

    2011-01-01

    Self-potential and direct current resistivity surveys are carried out at the Hidden Dam site in Raymond, California to assess present-day seepage patterns and better understand the hydrogeologic mechanisms that likely influence seepage. Numerical modeling is utilized in conjunction with the geophysical measurements to predict variably-saturated flow through typical two-dimensional dam cross-sections as a function of reservoir elevation. Several different flow scenarios are investigated based on the known hydrogeology, as well as information about typical subsurface structures gained from the resistivity survey. The flow models are also used to simulate the bulk electrical resistivity in the subsurface under varying saturation conditions, as well as the self-potential response using petrophysical relationships and electrokinetic coupling equations.The self-potential survey consists of 512 measurements on the downstream area of the dam, and corroborates known seepage areas on the northwest side of the dam. Two direct-current resistivity profiles, each approximately 2,500 ft (762 m) long, indicate a broad sediment channel under the northwest side of the dam, which may be a significant seepage pathway through the foundation. A focusing of seepage in low-topography areas downstream of the dam is confirmed from the numerical flow simulations, which is also consistent with past observations. Little evidence of seepage is identified from the self-potential data on the southeast side of the dam, also consistent with historical records, though one possible area of focused seepage is identified near the outlet works. Integration of the geophysical surveys, numerical modeling, and observation well data provides a framework for better understanding seepage at the site through a combined hydrogeophysical approach.

  16. The impact of damming on riverine fluxes to the ocean: A case study from Eastern Iceland.

    Science.gov (United States)

    Eiriksdottir, Eydis Salome; Oelkers, Eric H; Hardardottir, Jorunn; Gislason, Sigurdur Reynir

    2017-04-15

    Anthropogenic water management has extensively altered the world's river systems through impoundments and channel diversions to meet the human's need for water, energy and transportation. To illuminate the effect of such activities on the environment, this study describes the impact of the installation of the Kárahnjúkar Dam in Eastern Iceland on the transport of riverine dissolved- and particulate material to the ocean by the Jökulsá á Dal and the Lagarfljót rivers. This dam, completed in 2007, collects water into the 2.2 km 3 Hálslón reservoir and diverts water from the glacial Jökulsá á Dal river into the partially glaciated Lagarfljót lagoon via a headrace tunnel. The impact of the damming was evaluated by sampling water from both the Jökulsá á Dal and the Lagarfljót rivers over a 15 year period spanning from 1998 to 2013. The annual flux of most dissolved elements increased substantially due to the damming. The fluxes of dissolved Zn, Al, Co, Ti and Fe increased most by damming; these fluxes increased by 46-391%. These differences can be attributed to changed saturation states of common secondary minerals in the Jökulsá á Dal due to reduced discharge, increased residence time and dissolution of suspended material, and, to a lesser degree, reduced photosynthesis due to less transparency in the Lagarfljót lagoon. The removal of particulate material and thus decreasing adsorption potential in the Jökulsá á Dal is the likely reason for the Fe flux increase. In contrast, approximately 85% of the original riverine transported mass of particulate material is trapped by the dam; that which passes tends to be relatively fine grained, increasing the average specific surface area of that which continues to flow towards the ocean. Consequently, the particulate geometric surface area flux is decreased by only 50% due to the damming. The blooming of silica diatoms during the spring consumes dissolved silica from the coastal waters until it becomes

  17. A flavanone: 6, 7-dihydroxy-3, 5-dimethy I-4, methoxyflavone from the pods of acacia nilotica var astringens (sunt)

    International Nuclear Information System (INIS)

    Mohamed, A. A.; Abdel Karim, M.; Abdalla, A. A.

    2009-01-01

    A flavanone 6,7-dihydroxy-3, 5-dimethyl-4-methoxyflavone was isolated from the alcoholic extractives of the pods of acacia nilotica var astringens and structure was deduced on the basis of its IR, UV, NMR and mass spectra.(Author)

  18. Parent tree effects on reestablishment of Acacia koa in abandoned pasture and the influence of initial density on stand development

    Science.gov (United States)

    Paul G. Scowcroft

    2012-01-01

    Increasingly private landholders in Hawaii are considering native forest restoration for their lands, and some public agencies have already started such work. Initial efforts have focused on reestablishing Acacia koa to recover alien-grass-dominated sites. This study was done in Hakalau Forest National Wildlife Refuge, Island of Hawaii, to...

  19. Mixing of acacia bark and palm shells to increase caloric value of palm shells white charcoal briquette

    Science.gov (United States)

    Kurniawan, Edy Wibowo; Amirta, Rudianto; Budiarso, Edy; Arung, Enos Tangke

    2017-06-01

    Indonesia is greatly rich in biomass resources. Acacia bark waste utilization as a source of biomass is still very low, where as 10-20% of the potential of the wood. On the other hand waste palm shells have been partly utilized as boiler fuel oil plant as much as 62.4%, but the rest is still a waste pile or to the hardening of the estate path. This study aims to determine the effect of mixing an acacia bark with palm shells to increase the calorific value of palm shell white charcoal briquettes. The study was conducted by making white charcoal briquettes mixing 7% the acacia bark against of palm shells. As well as white charcoal briquettes control without any acacia bark. Then molds the briquettes in pyrolysis temperature at 600 ° C, 700 ° C and 800 ° C for pyrolysis time within 2 hours, 4 hours, and 6 hours. And the results of briquettes analysis in calorific value. The results showed that the caloric value of palm shell white charcoal briquettes increased from 29691.14 Kcal / kg to 31941.50 Kcal / kg.

  20. 78 FR 73434 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Acacia (Gum Arabic)

    Science.gov (United States)

    2013-12-06

    .... FDA-2011-F-0765] Food Additives Permitted for Direct Addition to Food for Human Consumption; Acacia...-based bars (e.g., 35 Same as above. breakfast and snack bars, granola, rice cereal bars). Soups and soup...--FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION 0 1. The authority citation...

  1. The Tracing of VOC Composition of Acacia Honey During Ripening Stages by Comprehensive Two-Dimensional Gas Chromatography.

    Science.gov (United States)

    Vyviurska, Olga; Chlebo, Róbert; Pysarevska, Solomiya; Špánik, Ivan

    2016-10-01

    In this study, VOC profiles of acacia flowers and honey samples at different processing stages and related comb wax samples were studied using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. It was found that some monoterpene compounds like α-pinene, myrcene, cis-β-ocimene, and 4-terpineol were common for acacia flower and all acacia honey samples, and the presence of verbenone and ocimene was first established in acacia honey. The most enriched VOC profile was obtained for raw honey before cell capping, where the final composition of lactones was achieved. On the contrary, number of alcohols, esters, and variety of terpenes, as well as their concentration in the honey samples decrease through ripening processes. Strained honey was characterized by the absence of camphor, α-bisabolol, and 3-carene, while isophorone and hexanoic acid were identified only in this type of honey. The composition of final VOC profile of honey was also influenced by the age of comb wax. The additional aromatic and lactone compounds, e.g., phenol, 1-phenylethanol, δ-hexalactone, and γ-heptalactone were observed for honey maturated in old dark comb wax. © 2016 Wiley-VHCA AG, Zürich.

  2. Passive restoration augments active restoration in deforested landscapes: the role of root suckering adjacent to planted stands of Acacia koa

    Science.gov (United States)

    Paul G. Scowcroft; Justin T. Yeh

    2013-01-01

    Active forest restoration in Hawaii’s Hakalau Forest National Wildlife Refuge has produced a network of Acacia koa tree corridors and islands in deforested grasslands. Passive restoration by root suckering has potential to expand tree cover and close gaps between planted stands. This study documents rates of encroachment into grassland, clonal...

  3. Influence of xanthan, guar, CMC and gum acacia on functional properties of water chestnut (Trapa bispinosa) starch.

    Science.gov (United States)

    Lutfi, Zubala; Nawab, Anjum; Alam, Feroz; Hasnain, Abid; Haider, Syed Zia

    2017-10-01

    This study was performed to determine the effect of xanthan, guar, CMC and gum acacia on functional and pasting properties of starch isolated from water chestnut (Trapa bispinosa). Morphological properties of water chestnut starch with CMC were studied by scanning electron microscopy (SEM). The addition of hydrocolloids significantly enhanced the solubility of water chestnut starch (WCS) while reduced swelling power and freeze-thaw stability. The hydrophilic tendency of WCS was increased by xanthan gum; however, with addition of gum acacia it decreased significantly. Starch was modified with guar and gum acacia exhibited highest% syneresis. Guar gum was found to be effective in increasing the clarity of water chestnut starch paste. The addition of CMC significantly reduced the pasting temperature of WCS indicating ease of gelatinization. The setback was accelerated in the presence of xanthan gum but gum acacia delayed this effect during the cooling of the starch paste. Only xanthan gum was found to be effective in increasing breakdown showing good paste stability of WCS. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. The Victoria Project, Sri Lanka. Hydrological analysis for Victoria Dam

    Energy Technology Data Exchange (ETDEWEB)

    Piper, B.S. [GU Projects (United Kingdom); Sutcliffe, J.V. [Gibb (Sir Alexander) and Partners (United Kingdom); Parks, Y.P. [Institute of Hydrology (United Kingdom)

    1994-03-01

    The hydrological analyses described in this paper formed an important part of the studies for the Victoria Project of which the Victoria Dam is the major component. The purpose of the hydrological studies was to provide consistent sets of river flow and climate data at the sites of the major components of the project, and to provide flood estimates for sizing the spillway and river diversion works. This paper outlines the approach used in the overall study, and then concentrates on aspects of specific relevance to the Victoria Dam. The main hydrological characteristics of the upper Mahaweli basin are presented as an introduction to the overall water balance; the humid climate made the appraisal of flow records relatively simple. Time series modelling was used to fill gaps in the observed flow records used for reservoir operation studies. The spillway design flood was based on the probable maximum precipitation (PMP) derived by maximizing a historic storm in which rainfall approaching the PMP covered most of the basin. Construction floods of moderate return period were estimated from a dimensionless analysis of regional flood records. The main lessons to be drawn are that water balance methods are of particular value in these humid monsoon conditions, while the ratio of the PMP to the maximum recorded storm is lower than would be the case in more arid regions. (author)

  5. Desrama, crescimento e predisposição à podridão-do-lenho em Acacia mangium Pruning on growth and heartrot predisposing in Acacia mangium

    Directory of Open Access Journals (Sweden)

    Helio Tonini

    2006-07-01

    Full Text Available A desrama é um procedimento que aumenta o valor e a qualidade da madeira. Entretanto, se realizada de forma inadequada pode reduzir o crescimento e constituir fator de predisposição à podridão-do-lenho. O objetivo deste trabalho foi estudar o efeito da intensidade e época da desrama sobre o crescimento inicial e incidência de árvores com ferimentos não cicatrizados de Acacia mangium. Foi instalado um experimento em delineamento de blocos ao acaso, com três repetições e cinco tratamentos: testemunha (sem desrama; desrama de troncos múltiplos e galhos a 50 e 70% da altura, em época de baixa e alta pluviosidade. As avaliações de crescimento e presença de ferimentos não cicatrizados foram feitas seis meses depois da aplicação dos tratamentos. A época e a intensidade de desrama, quando efetuadas aos 8 e 13 meses, não afetaram o crescimento em diâmetro e altura. Houve boa cicatrização de ferimentos em árvores desramadas oito meses depois do plantio, em época de baixa pluviosidade, independentemente da intensidade. Árvores desramadas aos 13 meses depois do plantio, em época de alta pluviosidade, demonstraram predisposição à podridão-do-lenho.Pruning increases quality and economic value of the wood. Inadequate pruning procedures, however, interfere negatively on growth and consist on a predisposing factor to heartrot. The objective of this work was to investigate the effect of intensity and season of pruning on initial growth and on incidence of Acacia mangium trees with non-occluded wounds. The experimental design was in randomized blocks with three replicates and five treatments: control (without pruning; pruning and singling at 50 and 70% of total height, in low and high precipitation season. Growth evaluations and the presence of non-occluded wounds were performed six months after treatments application. The season and intensity of pruning operations did not influence height and diameter growth. Efficient wound

  6. Diversity and localization of bacterial endosymbionts from whitefly species collected in Brazil.

    Science.gov (United States)

    Marubayashi, Julio Massaharu; Kliot, Adi; Yuki, Valdir Atsushi; Rezende, Jorge Alberto Marques; Krause-Sakate, Renate; Pavan, Marcelo Agenor; Ghanim, Murad

    2014-01-01

    Whiteflies (Hemiptera: Aleyrodidae) are sap-sucking insect pests, and some cause serious damage in agricultural crops by direct feeding and by transmitting plant viruses. Whiteflies maintain close associations with bacterial endosymbionts that can significantly influence their biology. All whitefly species harbor a primary endosymbiont, and a diverse array of secondary endosymbionts. In this study, we surveyed 34 whitefly populations collected from the states of Sao Paulo, Bahia, Minas Gerais and Parana in Brazil, for species identification and for infection with secondary endosymbionts. Sequencing the mitochondrial Cytochrome Oxidase I gene revealed the existence of five whitefly species: The sweetpotato whitefly Bemisia tabaci B biotype (recently termed Middle East-Asia Minor 1 or MEAM1), the greenhouse whitefly Trialeurodes vaporariorum, B. tabaci A biotype (recently termed New World 2 or NW2) collected only from Euphorbia, the Acacia whitefly Tetraleurodes acaciae and Bemisia tuberculata both were detected only on cassava. Sequencing rRNA genes showed that Hamiltonella and Rickettsia were highly prevalent in all MEAM1 populations, while Cardinium was close to fixation in only three populations. Surprisingly, some MEAM1 individuals and one NW2 population were infected with Fritschea. Arsenopnohus was the only endosymbiont detected in T. vaporariorum. In T. acaciae and B. tuberculata populations collected from cassava, Wolbachia was fixed in B. tuberculata and was highly prevalent in T. acaciae. Interestingly, while B. tuberculata was additionally infected with Arsenophonus, T. acaciae was infected with Cardinium and Fritschea. Fluorescence in situ hybridization analysis on representative individuals showed that Hamiltonella, Arsenopnohus and Fritschea were localized inside the bacteriome, Cardinium and Wolbachia exhibited dual localization patterns inside and outside the bacteriome, and Rickettsia showed strict localization outside the bacteriome. This study is

  7. Coastal habitat and biological community response to dam removal on the Elwha River

    Science.gov (United States)

    Foley, Melissa M.; Warrick, Jonathan A.; Ritchie, Andrew C.; Stevens, Andrew; Shafroth, Patrick B.; Duda, Jeff; Beirne, Matthew M.; Paradis, Rebecca; Gelfenbaum, Guy R.; McCoy, Randall; Cubley, Erin S.

    2017-01-01

    Habitat diversity and heterogeneity play a fundamental role in structuring ecological communities. Dam emplacement and removal can fundamentally alter habitat characteristics, which in turn can affect associated biological communities. Beginning in the early 1900s, the Elwha and Glines Canyon dams in Washington, USA, withheld an estimated 30 million tonnes of sediment from river, coastal, and nearshore habitats. During the staged removal of these dams—the largest dam removal project in history—over 14 million tonnes of sediment were released from the former reservoirs. Our interdisciplinary study in coastal habitats—the first of its kind—shows how the physical changes to the river delta and estuary habitats during dam removal were linked to responses in biological communities. Sediment released during dam removal resulted in over a meter of sedimentation in the estuary and over 400 m of expansion of the river mouth delta landform. These changes increased the amount of supratidal and intertidal habitat, but also reduced the influx of seawater into the pre-removal estuary complex. The effects of these geomorphic and hydrologic changes cascaded to biological systems, reducing the abundance of macroinvertebrates and fish in the estuary and shifting community composition from brackish to freshwater-dominated species. Vegetation did not significantly change on the delta, but pioneer vegetation increased during dam removal, coinciding with the addition of newly available habitat. Understanding how coastal habitats respond to large-scale human stressors—and in some cases the removal of those stressors—is increasingly important as human uses and restoration activities increase in these habitats.

  8. Mapping invasive alien Acacia dealbata Link using ASTER multispectral imagery: a case study in central-eastern of Portugal

    Directory of Open Access Journals (Sweden)

    Filipe Martins

    2016-12-01

    Full Text Available Aim of the study: Acacia dealbata is an alien invasive species that is widely spread in Portugal. The main goal of this study was to produce an accurate and detailed map for this invasive species using ASTER multispectral imagery. Area of study: The central-eastern zone of Portugal was used as study area. This whole area is represented in an ASTER scene covering about 321.1 x 103 ha. Material and methods: ASTER imagery of two dates (flowering season and dry season were classified by applying three supervised classifiers (Maximum Likelihood, Support Vector Machine and Artificial Neural Networks to five different land cover classifications (from most generic to most detailed land cover categories. The spectral separability of the land cover categories was analyzed and the accuracy of the 30 produced maps compared. Main results: The highest classification accuracy for acacia mapping was obtained using the flowering season imagery, the Maximum Likelihood classifier and the most detailed land cover classification (overall accuracy of 86%; Kappa statistics of 85%; acacia class Kappa statistics of 100%. As a result, the area occupied by acacia was estimated to be approximated 24,770 ha (i.e. 8% of the study area. Research highlights: The methodology explored proved to be a cost-effective solution for acacia mapping in central-eastern of Portugal. The obtained map enables a more accurate and detailed identification of this species’ invaded areas due to its spatial resolution (minimum mapping unit of 0.02 ha providing a substantial improvement comparably to the existent national land cover maps to support monitoring and control activities. Keywords: remote sensing; invasive alien species; land cover mapping; vegetation mapping.

  9. Mapping invasive alien Acacia dealbata Link using ASTER multispectral imagery: a case study in central-eastern of Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Martins, F.; Alegria, C.; Artur, G.

    2016-07-01

    Aim of the study: Acacia dealbata is an alien invasive species that is widely spread in Portugal. The main goal of this study was to produce an accurate and detailed map for this invasive species using ASTER multispectral imagery. Area of study: The central-eastern zone of Portugal was used as study area. This whole area is represented in an ASTER scene covering about 321.1 x 103 ha. Material and methods: ASTER imagery of two dates (flowering season and dry season) were classified by applying three supervised classifiers (Maximum Likelihood, Support Vector Machine and Artificial Neural Networks) to five different land cover classifications (from most generic to most detailed land cover categories). The spectral separability of the land cover categories was analyzed and the accuracy of the 30 produced maps compared. Main results: The highest classification accuracy for acacia mapping was obtained using the flowering season imagery, the Maximum Likelihood classifier and the most detailed land cover classification (overall accuracy of 86%; Kappa statistics of 85%; acacia class Kappa statistics of 100%). As a result, the area occupied by acacia was estimated to be approximated 24,770 ha (i.e. 8% of the study area). Research highlights: The methodology explored proved to be a cost-effective solution for acacia mapping in central-eastern of Portugal. The obtained map enables a more accurate and detailed identification of this species’ invaded areas due to its spatial resolution (minimum mapping unit of 0.02 ha) providing a substantial improvement comparably to the existent national land cover maps to support monitoring and control activities. (Author)

  10. Experience with embankment dam safety evaluation in Alberta

    International Nuclear Information System (INIS)

    Houston, M.; Morgenstern, N.R.

    1989-01-01

    Following a rash of dam failures in the 1970s, many jurisdictions responded with the implementation of both legislation and regulations mandating dam safety evaluations. Almost all dams in Alberta are embankment dams, of which failures are mainly caused by: overtopping during flood discharge due to inadequate spillway capacity or non-functioning floodgates; internal erosion along the dam foundation interface; non-homogeneity in the foundation or dam, leading to foundation failure or erosion; large settlements in the foundation; cracks following settlement, with resultant piping; and liquefaction. Summaries are presented of a series of case histories of dam safety evaluations conducted in Alberta where the outcome was not routine. The case histories describe evaluations carried out at the following dams. The Bighorn hydroelectric development was completed in 1972, and measured seepage was found to be ten times greater than a recommended alert level. Dam safety evaluations concluded that the performance of the dam and concrete cutoff wall is satisfactory, but the owner reads all monitoring instrumentation on a regular basis and seeks on-going review from consultants. The Three Sisters Dam is a 21 m high homogeneous embankment hydroelectric dam. Very large seepage flows were found, and although remedial measures have been effective, extreme vigilence with an intensive inspection and monitoring program is required. Other case studies detail seepage monitoring at the St. Mary Dam, complex seepage patterns at Waterton Dam and Tavers Dam, and material durability studies at Hartung Dam and Murray Dam. The importance of good records and construction and performance histories is emphasized. 12 figs., 10 refs

  11. Numerical modelling dam break analysis for water supply project

    International Nuclear Information System (INIS)

    Lariyah, M S; Vikneswaran, M; Hidayah, B; Muda, Z C; Thiruchelvam, S; Isham, A K Abd; Rohani, H

    2013-01-01

    Dam provides many benefits to the society, but it can also cause extensive damage to downstream area when it fails. Dam failure can cause extensive damage to properties and loss of human life due to short warning time available. In general, dam spillway was designed to drain the maximum discharge from the dam during the Probable Maximum Flood (PMF). The spillway is functioned to prevent the dam from failure due to overtopping, which can lead to the dam failure. Dam failure will result in large volume of water travelling at very high velocity to the downstream area of the dam. It can cause extensive property damage, destruction of important facilities, and significant loss of human life along the way. Due to the potential of high hazard it poses to the downstream area, a dam break analysis is considered very essential. This paper focuses into the dam failure analysis for Kahang Dam by prediction of breach flow hydrographs and generation of inundation map at downstream area. From the PMF scenario simulation, the maximum inflow is 525.12 m 3 /s and peak discharge from the dam during dam failure is 6188m 3 /s. The results are able to provide information for preparation of Emergency Response Plan (PMF), in which appropriate steps can be taken by relevant authorities to avoid significant loss of human lives.

  12. Seismic response of concrete gravity dam reinforced with FRP sheets on dam surface

    Directory of Open Access Journals (Sweden)

    Hong Zhong

    2013-10-01

    Full Text Available This paper aims at exploring the effects of anti-seismic reinforcement with the fiber-reinforced polymer (FRP material bonded to the dam surface in dam engineering. Time-history analysis was performed to simulate the seismic failure process of a gravity dam that was assumed to be reinforced at the locations of slope discontinuity at the downstream surface, part of the upstream face, and the dam heel. A damage model considering the influence of concrete heterogeneity was used to model the nonlinearity of concrete. A bond-slip model was applied to the interface between FRP and concrete, and the reinforcement mechanism was analyzed through the bond stress and the stress in FRP. The results of the crack pattern, displacement, and acceleration of the reinforced dam were compared with those of the original one. It is shown that FRP, as a reinforcement material, postpones the occurrence of cracks and slows the crack propagation, and that cracks emanating from the upstream surface and downstream surface are not connected, meaning that the reinforced dam can retain water-impounding function when subjected to the earthquake. Anti-seismic reinforcement with FRP is therefore beneficial to improving the seismic resistant capability of concrete dams.

  13. Effect of feeding Neem (Azadirachta indica) and Acacia (Acacia senegal) tree foliage on nutritional and carcass parameters in short-eared Somali goats.

    Science.gov (United States)

    Hailemariam, Samson; Urge, Mengistu; Menkir, Sissay

    2016-02-01

    The study was conducted to determine the effects of dried foliage of Acacia senegal and Neem (Azadirachta indica) tree supplementations on feed intake, nutrient digestibility, growth, and carcass parameters in short-eared Somali goats. Twenty male intact short-eared Somali goat yearlings with an average live weight of 16.2 ± 1.08 (Mean ± SD) were assigned to four treatment groups, which comprised a basal diet of hay alone (T1) and supplementation with the tree foliages. Supplements consisted Neem tree (T2), A. senegal (T3) and the mixture of the two (1:1 ratio; T4) dried foliages. The crude protein (CP) content of Neem tree foliage, A. senegal, and their mixture were 16.92, 17.5 and 17.01 % of dry matter (DM), respectively. Total DM intake and digestibility of DM and organic matter were significantly (P senegal (67 %). The final body weights were higher (P Senegal. An average daily body weight (BW) gain was higher (P senegal (8.3 kg) among the supplemented groups, all of which are higher than the control (4.9 kg). It is concluded that the supplementation with tree foliage, especially with A. senegal tree foliage, on grass hay encouraged a better utilization of nutrients and animal performance as compared to goats fed on a basal diet of grass hay only.

  14. Influence of Acacia trees on soil nutrient levels in arid lands

    Science.gov (United States)

    De Boever, Maarten; Gabriels, Donald; Ouessar, Mohamed; Cornelis, Wim

    2014-05-01

    The potential of scattered trees as keystone structures in restoring degraded environments is gaining importance. Scattered trees have strong influence on their abiotic environment, mainly causing changes in microclimate, water budget and soil properties. They often function as 'nursing trees', facilitating the recruitment of other plants. Acacia raddiana is such a keystone species which persists on the edge of the Sahara desert. The study was conducted in a forest-steppe ecosystem in central Tunisia where several reforestation campaigns with Acacia took place. To indentify the impact of those trees on soil nutrients, changes in nutrient levels under scattered trees of three age stages were examined for the upper soil layer (0-10 cm) at five microsites with increasing distance from the trunk. In addition, changes in soil nutrient levels with depth underneath and outside the canopy were determined for the 0-30 cm soil layer. Higher concentrations of organic matter (OM) were found along the gradient from underneath to outside the canopy for large trees compared to medium and small trees, especially at microsites close to the trunk. Levels of soluble K, electrical conductivity (EC), available P, OM, total C and N decreased whereas pH and levels of soluble Mg increased with increasing distance from tree. Levels of soluble Ca and Na remained unchanged along the gradient. At the microsite closest to the trunk a significant decrease in levels of soluble K, EC, OM, available P, total C and N, while a significant increase in pH was found with increasing depth. The concentration of other nutrients remained unchanged or declined not differently underneath compared to outside the canopy with increasing depth. Differences in nutrient levels were largely driven by greater inputs of organic matter under trees. Hence, Acacia trees can affect the productivity and reproduction of understory species with the latter in term an important source of organic matter. This positive feedback

  15. GANANCIA GENÉTICA ESPERADA EN Acacia mangium EN LOS CHILES, ZONA NORTE DE COSTA RICA

    Directory of Open Access Journals (Sweden)

    Benjam\\u00EDn Pavlotzky-Blank

    2012-01-01

    Full Text Available Ganancia genética esperada en Acacia mangium en Los Chiles, zona norte de Costa Rica. Con el objetivo de seleccionar los materiales de mayor crecimiento y calidad de fuste en Acacia mangium, se evaluó un ensayo de progenie de Acacia mangium Willd. conformado por veinticinco familias. El ensayo fue establecido en Los Chiles, zona norte de Costa Rica, en 2006 con evaluaciones en el 2007 y en 2010. Se utilizó material genético seleccionado por la Cooperativa de Conservación y Mejoramiento Genético Forestal "GENFORES", en Costa Rica y Colombia. Cada familia estuvo representada por 48 progenies, plantadas en cuatro parejas distribuidas en forma aleatoria dentro de cada uno de los seis bloques del ensayo. Se evaluó el diámetro a la altura de pecho "DAP", incremento en DAP, adaptabilidad al sitio, número de trozas comerciales, bifurcación, altura de bifurcación, calidad de las primeras cuatro trozas. Se determinó el volumen de madera comercial por árbol y hectárea. Los datos fueron analizados por medio del software SELEGEN de EMBRAPA para obtener los parámetros genéticos. Todos los caracteres registraron valores de heredabilidad media familiar superiores a 0,68. Si se seleccionaran los dos mejores individuos dentro de las mejores doce familias, se obtendría una ganancia genética del 40,8% en volumen comercial/ha a los cuatro años de edad. Esta ganancia corresponde a un volumen comercial de 91,65 m3/ha, a una tasa de 22,9 m3/ha/año. Las dos procedencias derivadas de Colombia son signifi cativamente superiores a los demás materiales evaluados. El análisis de correlación genética entre caracteres muestra que la tasa de crecimiento diamétrico se expresa desde temprana edad en esta especie, lo que podría ser utilizado a futuro en una selección a menor edad.

  16. Geoecosystem-related dynamics of Acacia populations in the Israeli hyper-arid Arava Valley

    Science.gov (United States)

    Stavi, Ilan; Avni, Yoav; Yizhaq, Hezi; Bel, Golan; Ginat, Hanan

    2017-04-01

    Similar to other Middle-Eastern and North-African drylands, Acacia populations across the hyper-arid Arava Valley of Israel have experienced dramatic phonological changes during the last few decades. These changes have been expressed with high mortality rates and low recruitment rates. Species of the Acacia trees across the region include the A. pachyceras, A. raddiana, and A. tortilis. We studied the recruitment and decay rate of seedlings. Data obtained revealed that during a whole year after germination, overall survival rate of seedlings was 2%. Also, data showed that the main impediment to recruitment and survival of seedlings was insufficient access to soil-water, resulting in their mortality due to drying. Another, secondary impediment was imposed by erosional and depositional processes under heavy floods, resulting in the elimination or burial of seedlings. Modeling of results revealed that the drying of seedlings is defined with a constant mortality rate, which fits an exponential decay function. At the same time, seedling mortality due to fluvial processes is defined with a mortality rate that grows with time, which fits a Gaussian decay function. Also, we investigated the effect of latitude, basin size, and microhabitat on vitality of existing trees. Results showed negative effect of latitude on tree mortality, fitting with the generally greater precipitation rates in the northern- than in the southern- Arava Valley. At the same time, no effect on tree mortality was recorded for basin size, proposing that in such extreme drylands, runoff ratio becomes more non-linear with increasing watershed size because of the greater dominance of ephemeral stream transmission losses, as well as due to the partial storm area coverage. Nor did the location in microhabitat across the valley floor affect tree mortality rate, highlighting the bimodal effect of greater access to flood water, potentially increasing survivability of old trees, but at the same time, imposing

  17. Entomofauna Associada a Galhos de Acacia mangium Willd. Roletados por Oncideres saga (Dalman (Coleoptera: Cerambycidae

    Directory of Open Access Journals (Sweden)

    Gláucia Cordeiro

    2010-04-01

    Full Text Available O estudo da entomofauna associada aos galhos e fustes roletados por Oncideres saga (Dalman é importante para conhecermos seus possíveis inimigos naturais. Portanto, este trabalho teve como objetivo registrar os insetos associados aos galhos e fustes de Acacia mangium Willd. roletados por O. saga, em Coimbra-MG. Galhos e fustes roletados de A. mangium foram coletados de janeiro a abril de 2007. Este material foi vistoriado, armazenados em sacolas, feitas com tela plástica, e mantidos em sala com condições controladas (25,4±0,3°C e 66,7±1,4%. Constatou-se a presença de uma espécie, não determinada, de Scolytidae e a emergência de quatro espécies de Cerambycidae: Engyum quadrinotatum Thomsom; Eburodacrys sexmaculata (Olivier; Achryson surinamum (Linnaeus e Neoclytus pusillus (Laporte & Gory. Isto posto, fica evidenciada a necessidade de estudos com o objetivo de verificar qual o comportamento destes insetos em relação ao serrador O. saga.Insects associated with branches of Acacia mangium Willd. girdled by Oncideres saga (Dalman (Coleoptera: CerambycidaeAbstract. The study of the insects associated with branches and stems girdled by Oncideres saga (Dalman is important to know its possible natural enemies. Therefore, these work had the objective of register the insects associated with branches and stems girdled of Acacia mangium Willd. by this twig girdler beetle, in Coimbra, state of Minas Gerais, Brazil. Stems and branches of A. mangium were collected in January/2007 to April/2007. This material has been inspected, stored in plastic bags, and kept in a room with controlled conditions (25.4 ± 0.3°C and 66.7 ± 1.4%. It was noted the presence of a non-determined species of Scolytidae and the emergence of four species of Cerambycidae: Engyum quadrinotatum Thomsom; Eburodacrys sexmaculata (Olivier; Achryson surinamum (Linnaeus and Neoclytus pusillus (Laporte & Gory. It can be concluded that studies are needed with the objective of

  18. Lac Courte Oreilles Hydro Dam Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Jason [Lac Courte Oreilles, Hayward, WI (United States); Meyers, Amy [Kiser Hydro, LLC, Norway, MI (United States)

    2014-12-31

    The main objective of this project was to investigate upgrading the existing hydro power generating system at the Winter Dam. The tribe would like to produce more energy and receive a fair market power purchase agreement so the dam is no longer a drain on our budget but a contributor to our economy. We contracted Kiser Hydro, LLC Engineering for this project and received an engineering report that includes options for producing more energy with cost effective upgrades to the existing turbines. Included in this project was a negotiation of energy price sales negotiations.

  19. Hydroelectric dams need billions for rehab

    International Nuclear Information System (INIS)

    Carr, F.H.; Soast, A.

    1993-01-01

    Many of the Corps of Engineers older hydroelectric dams will require major rehabilitation over the next ten years. Preventive maintenance, repair work, and major rehabilitation of the Corp's hydro dams in inadequate because the revenue generated by sales of electricity, by law, is returned to the Treasury. Most multimillion dollar rehabilitation projects require specific approval for funding by Congress and securing it is a long and difficult process. It is hoped the funding problem will soon be addressed by the Clinton administration. Already, nearly one-sixth of the 2,154 Mw of hydro is unavailable because with hydro units are either out of service or operating at less than full capacity

  20. Official opening of the Olympic Dam project

    International Nuclear Information System (INIS)

    Parbo, A.

    1989-01-01

    This is the text of an address given on November 5, 1988 to mark the commencement of production of copper, uranium, gold and silver from the first stage of the Olympic Dam project at Roxby Downs, South Australia. The huge deposit was discovered in 1975 and years of exploration, underground development, metallurgical testing, planning and establishing the infrastructure followed, at a cost of $750 million. 740 people are now employed at Olympic Dam. The first shipment of copper and uranium oxide left for Sweden at the end of November 1988. The deposit is able to support a much higher production rate as the market for the products, particularly uranium, improves

  1. National Inventory of Dams Coastal California Extract 2010

    Data.gov (United States)

    California Department of Resources — The National Inventory of Dams (NID) is a congressionally authorized database, which documents dams in the U.S. and its territories. The NID was most recently...

  2. National Inventory of Dams Coastal California Extract 2010

    Data.gov (United States)

    California Natural Resource Agency — The National Inventory of Dams (NID) is a congressionally authorized database, which documents dams in the U.S. and its territories. The NID was most recently...

  3. Inventory of Dams in the State of Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Permitted dams in Iowa and associated attributes, as recorded by the Floodplain Section of the DNR. The dams regulated are those with the parameters listed below: a....

  4. Macrobenthic Communities of the Dam Neck Disposal Site.

    Science.gov (United States)

    1985-02-01

    catharinensis Muller Byblis aerrata Smith 0 Caprellidae app. Corophium app. Gammarus sp. Listriella barnardi Wigley Protohaustorius spp...TABLE 2 : Hydrographic Measurements at Dam Neck Stations (A) - Dam Neck Extension Stations Station Date Bottom Salinity Bottom Temperature Depth (ppt

  5. Timber box dams - an alternative for small power plants

    International Nuclear Information System (INIS)

    Lia, Leif

    2005-01-01

    The article discusses timber dams as an alternative concrete or stone filling dams for small power plants. Old knowledge, advantages and disadvantages are mentioned as well as some examples and environmental aspects

  6. Dam-Break Flood Analysis Upper Hurricane Reservoir, Hartford, Vermont

    National Research Council Canada - National Science Library

    Acone, Scott

    1995-01-01

    .... Various dam break flood conditions were modeled and inundation maps developed. Based on this analysis the dam is rated a Class 2 or significant hazard category in terms of its potential to cause downstream damage...

  7. Investigation on the Causes of Cracking in Earth Dams (Case study: Mahmood-Abad Earth Dam

    Directory of Open Access Journals (Sweden)

    H. Rahimi

    2016-09-01

    Full Text Available Introduction: Cracking of earth dams is a one of the main threat causes of stability of embankment dams. In this research by modeling of the behavior of an embankment dam and employing conditions of the earthquake, the reasons of cracking were inspected using by modeling of earth dam behavior. Based on the literature, one of the main causes of dam failures is sliding and cracking of the dam structure during earthquake. Localized liquefaction of foundation soils was one of the causes of the observed post-earthquake distress within these dams. Material and Methods: In order to study the causes and the results of crack on earth dams, Mahmoodabad earthen dam with a height of 19 m, is located in Zanjan province, northwest of Iran, which suffered a longitudinal crack on the crest and slight sliding of the upstream slope due to 2001 Avaj earthquake was studied. This dam has faced earthquake two times with an interval of two years. During the first earthquake with the magnitude about 6.6 in Richter scale small longitudinal cracks had created on the crest. The developed cracks had been repaired by injecting the cement and then has been hidden by passing the time. After the second earthquake with the magnitude about 6.5 in Richter scale the hidden cracks had been appeared again and the slight movement of the upper slopes of dam reported. Based on the site investigation and documented information about dam, including maps and parameter data, the behavior of the dam has modeled by using Plaxis as a finite element model. In order to check the accuracy of the design of dam, the stability analysis has been conducted using by Xslope as a limit equilibrium model. The foundation conditions and the Geotechnical properties of the layer beneath the dam has been inspected by open excavation. Results and Discussion: Underground investigation about Geotechnical properties of dam foundation has showed that there is a thin sandy layer confined in alluvium material of the

  8. Dams and transnational advocacy: Political opportunities in transnational collective action

    Science.gov (United States)

    Fu, Teng

    Possible arguments to explain the gradual decline in big dam development and its site transferring from developed to developing countries include technical, economic, and political factors. This study focuses on the political argument---the rise of transnational anti-dam advocacy and its impact on state policy-making. Under what conditions does transnational anti-dam advocacy matter? Under what conditions does transnational advocacy change state dam policies (delay, scale down, or cancel)? It examines the role of transnational anti-dam actors in big dam building in a comparative context in Asia. Applying the social movement theory of political opportunity structure (POS) and using the qualitative case-study method, the study provides both within-case and cross-case analyses. Within-case analysis is utilized to explain the changing dynamics of big dam building in China (Three Gorges Dam and proposed Nu/Salween River dam projects), and to a lesser extent, Sardar Sarovar Project in India and Nam Theun 2 Dam in Laos. Different domestic and international POS (DPOS and IPOS) impact the strategies and outcomes of anti-dam advocacies in these countries. The degree of openness of the POS directly affects the capacity of transnational efforts in influencing state dam policies. The degree of openness or closure is measured by specific laws, institutions, discourse, or elite allies (or the absence of these) for the participation of non-state actors on big dam issues at a particular moment. This degree of openness is relative, varying over time, across countries and regions. This study finds that the impact of transnational anti-dam activism is most effective when both DPOS and IPOS are relatively open. Transnational anti-dam advocacy is least effective in influencing state dam policies when both DPOS and IPOS are relatively closed. Under a relatively open DPOS and closed IPOS, transnational anti-dam advocacy is more likely to successfully change state dam policies and even

  9. Dynamic analysis of Moste concrete gravity dam with CADAM software

    OpenAIRE

    Novak, Matic

    2013-01-01

    In this thesis a short literature overview is given for simplified dynamic analysis of concrete gravity dams. A parametric study using CADAM software was conducted. By this study the Moste concrete gravity dam response was analyzed for different loads and earthquake accelerations. The results showed that safety of Moste dam is comparable to its design safety. Also is shown that the Moste dam would sustain more intense horizontal ground movement than the designed values for sliding and overtur...

  10. Effect of Inoculation of Acacia senegal mature trees with Mycorrhiza and Rhizobia on soil properties and microbial community structure

    Science.gov (United States)

    Assigbetsé, K.; Ciss, I.; Bakhoum, N.; Dieng, L.

    2012-04-01

    Inoculation of legume plants with symbiotic microorganisms is widely used to improve their development and productivity. The objective of this study was to investigate the effect of inoculation of Acacia senegal mature trees with rhizobium (Sinorhizobium) and arbuscular mycorrhizal fungus (G. mosseae, G. fasciculatum, G. intraradices) either singly or in combination, on soil properties, activity and the genetic structure of soil microbial communities. The experiment set up in Southern Senegal consisted of 4 randomized blocks of A. senegal mature trees with 4 treatments including inoculated trees with Rhizobium (R), mycorrhizal fungus (M) and with Rhizobium+mycorhizal fungus (RM) and non-inoculated control (CON). Soil were sampled 2 years after the inoculation. Soil pH, C and N and available P contents were measured. The microbial abundance and activity were measured in terms of microbial biomass C (MBC) and basal soil respiration. The community structure of the total bacterial, diazotrophic and denitrifying communities was assessed by denaturing gradient gel electrophoresis of 16S rDNA, nifH and nirK genes respectively. Inoculations with symbiont under field conditions have increased soil pH. The C and N contents were enhanced in the dual-inoculated treatments (RM). The mycorrhized treatment have displayed the lowest available P contents while RM and R treatments exhibited higher contents rates. The microbial biomass C rates were higher in treatments co-inoculated with AM fungi and Rhizobium than in those inoculated singly with AM fungi or Rhizobium strains. The basal soil respiration were positively correlated to MBC, and the highest rates were found in the co-inoculated treatments. Fingerprints of 16S rDNA gene exhibited similar patterns between inoculated treatments and the control showing that the inoculation of mature trees have not impacted the total bacterial community structure. In contrast, the inoculated treatments have displayed individually different

  11. Mechanistic Insight into Salt Tolerance of Acacia auriculiformis: The Importance of Ion Selectivity, Osmoprotection, Tissue Tolerance, and Na+ Exclusion

    Science.gov (United States)

    Rahman, Md. M.; Rahman, Md. A.; Miah, Md. G.; Saha, Satya R.; Karim, M. A.; Mostofa, Mohammad G.

    2017-01-01

    Salinity, one of the major environmental constraints, threatens soil health and consequently agricultural productivity worldwide. Acacia auriculiformis, being a halophyte, offers diverse benefits against soil salinity; however, the defense mechanisms underlying salt-tolerant capacity in A. auriculiformis are still elusive. In this study, we aimed to elucidate mechanisms regulating the adaptability of the multi-purpose perennial species A. auriculiformis to salt stress. The growth, ion homeostasis, osmoprotection, tissue tolerance and Na+ exclusion, and anatomical adjustments of A. auriculiformis grown in varied doses of seawater for 90 and 150 days were assessed. Results showed that diluted seawater caused notable reductions in the level of growth-related parameters, relative water content, stomatal conductance, photosynthetic pigments, proteins, and carbohydrates in dose- and time-dependent manners. However, the percent reduction of these parameters did not exceed 50% of those of control plants. Na+ contents in phyllodes and roots increased with increasing levels of salinity, whereas K+ contents and K+/Na+ ratio decreased significantly in comparison with control plants. A. auriculiformis retained more Na+ in the roots and maintained higher levels of K+, Ca2+ and Mg2+, and K+/Na+ ratio in phyllodes than roots through ion selective capacity. The contents of proline, total free amino acids, total sugars and reducing sugars significantly accumulated together with the levels of malondialdehyde and electrolyte leakage in the phyllodes, particularly at day 150th of salt treatment. Anatomical investigations revealed various anatomical changes in the tissues of phyllodes, stems and roots by salt stress, such as increase in the size of spongy parenchyma of phyllodes, endodermal thickness of stems and roots, and the diameter of root vascular bundle, relative to control counterparts. Furthermore, the estimated values for Na+ exclusion and tissue tolerance index suggested that

  12. Algunas propiedades físico-mecánicas y de trabajabilidad de la Acacia melanoxylon

    Directory of Open Access Journals (Sweden)

    Elliot Correcha R.

    1984-01-01

    Full Text Available El presente artículo muestra los resultados obtenidos de las propiedades físicas como: gravedad especifica anhidra, seca al aire y en estado verde; densidad verde, seca al aire, anhidra y básica; y contracciones radial, tangencial y volumétrica. Propiedades mecánicas tales como: flexión estática en estado verde y seca al aire, compresión paralela al grano en estado verde y seca al aire. Además ensayos de trabajabilidad de cepillado, moldurado, taladrado y torneado de la Acacia melanoxylon. Se usaron metodologías establecidas por ASTM, ICONTEC y COPANT. Estos ensayos se realizaron en los laboratorios del Instituto de Ensayos e Investigación (IEI de la facultad de Ingenleria, Universidad Nacional de Bogotá.

  13. Anti-free radical activities of kaempferol isolated from Acacia nilotica (L.) Willd. Ex. Del.

    Science.gov (United States)

    Singh, Rajbir; Singh, Bikram; Singh, Sukhpreet; Kumar, Neeraj; Kumar, Subodh; Arora, Saroj

    2008-12-01

    In the present study the polyphenolic compound has been isolated from methanol extract of Acacia nilotica Willd. Ex. Del. which has been identified as kaempferol (AN-5) by NMR and mass spectroscopy. The antioxidant potential of the AN-5 was demonstrated in several in vitro assays: measuring the proton radical scavenging activity (DPPH scavenging assay), hydroxyl radical scavenging activity (deoxyribose degradation assay), metal chelating activity, reducing power and inhibition of lipid peroxidation. It was found that the effect of the compound AN-5 was strongly dose dependent up to the concentrations 1-50 microg/ml in DPPH assay and 1-100 microg/ml in deoxyribose degradation assay but did not show further change above the highest concentrations.

  14. Water use efficiency studies of Acacia senegal (L.) Willd provenances in Sudan

    International Nuclear Information System (INIS)

    Mustafa, A.F.; Elamin, K.H.; Salih, A.A.

    1996-01-01

    An experiment was conducted in 1989 to screen Acacia senegal L. Willd provenances collected from within the natural gum belt for high water use efficiency. Thirteen provenances were tested for water use efficiency and consequently 6 out of them were selected for further screening. The selection was based on their performance in the preliminary screening. Both the preliminary and the detailed study revealed that provenances 7, 3 and 11 combine high dry matter production with high water use efficiency. Water use efficiency and dry matter production appears to be negatively correlated with root length density and root/shoot ratios. Provenances 7 which exhibited the highest water use efficiency and dry matter yield had the lowest root/shoot ratio and also a low root length density. Based on these studies provenance 7 can be considered a suitable candidate for introduction into gum-belt of Sudan through for rehabilitation of this region. (author). 5 refs, 1 fig., 3 tabs

  15. Spatial and molecular aspects of hemiparasites parasitising Acacia spp

    DEFF Research Database (Denmark)

    Dueholm, Bjørn

    shrubs neighbouring the root hemiparasites. The hemiparasites may further impair reproduction of the host and impact other trophic levels associated with the host. Traits of Acacia ligulata were therefore investigated further in terms of seeds per seedpods, seed mass and phyllode C/N ratios. Indications...... not result in differences of larval mass. Finally, to further investigate the belowground-aboveground link, phyllodes from A. acuminata were used for an RNA-sequencing (RNA-Seq) experiment to investigate gene expression in individuals, non-parasitised or parasitised by Santalum spicatum. Two transcriptomes....... The annotated transcriptomes together with identified markers enable further relational and gene expression studies with either shoot or root hemiparasites in either natural communities or plantations....

  16. Biosynthesis, characterization and antibacterial studies of silver nanoparticles using pods extract of Acacia auriculiformis

    Science.gov (United States)

    Nalawade, Pradnya; Mukherjee, Poulomi; Kapoor, Sudhir

    2014-08-01

    The present study reports an environmental friendly method for the synthesis of silver nanoparticles (Ag NPs) using an aqueous extract of Acacia auriculiformis that acts as reducing agent as well as capping agent. The obtained NPs were characterized by UV-vis absorption spectroscopy and showed a sharp surface plasmon absorption band at ∼400 nm. Fourier transform infrared spectroscopy (FTIR) showed nanoparticles were capped with plant compounds. Transmission electron microscopy (TEM) showed that the particles were spherical in nature with diameter ranging from 20 to 150 nm depending on the pH of the solution. The as-synthesized Ag NPs showed antibacterial activity against both Gram negative and Gram positive bacteria with more efficacy against Gram negative bacteria.

  17. Improvement of the mechanical performance of Fergoug dam sediments treated for reuse in road engineering

    Directory of Open Access Journals (Sweden)

    Abdelkader LAROUCI

    2018-01-01

    Full Text Available The phenomenon of siltation is one of the main problems facing many dams throughout the world, and particularly in Algeria. The mud, before and even after extraction, is always harmful. Indeed, mud is a harmful material, first for dams, because it reduces their capacity of water storage, and second, for the environment following the desilting operations that generate large quantities of materials that occupy and sometimes pollute large areas. However, these materials can be exploited differently and used in other fields. The envisaged research work relates to real cases of silted dams, such as the dam of Fergoug (western Algeria whose siltation rate is very high; it is estimated at 97% of its initial capacity which, according to the National Agency for Dams (Agence Nationale des Barrages - ANB, is equal to 18 million m3. The large quantities of silt extracted present an environmental problem, and its use as a local raw material for the manufacture of civil engineering materials can contribute to solve this problem. The vulnerable lands of the sub-catchment of Wadi Fergoug (Fergoug River extend over an area of 122 km2, from a total surface of 8340 km2 for the dam catchment area. There is a great diversity of superficial formations with predominantly clay soils from marly formations. The rate of specific erosion has increased to 160 T/ km2/ year due to irregular annual rainfall resulting from a succession of dry and wet years. Sedimentary materials, which are found in considerable quantities, were collected at the foot of the dam, on its right bank. This study attempts to find a recycling pathway for these sediments. The objective of the present work is to investigate the behavior of silt from the dam of Fergoug (Algeria for the purpose of using it in road construction (foundation and base layers. The method adopted is to reconstitute, in the laboratory, samples of mixtures containing road aggregates with different proportions of silt. These

  18. Seismic performance assessment of latyan concrete buttress dam ...

    African Journals Online (AJOL)

    In order to design earthquake resistant dams and evaluate the safety of existing dams that will be exposed to future earthquakes, it is essential to have accurate and reliable analysis procedures to predict the stresses and deformations in dams subjected to earthquake ground motion. For a damwater- foundation system, the ...

  19. Characterisation of gold tailings dams of the Witwatersrand Basin ...

    African Journals Online (AJOL)

    The oxygen diffusion data reveal that the flow of oxygen in the Witwatersrand tailings dams is controlled by secondary porosity (i.e. cracks caused by roots on the dam surface). The age of the dam does not have a significant bearing on the extent to which the oxidised zone development and subsequently AMD can progress.

  20. Nonlinear analysis of concrete gravity dams under normal fault motion

    Directory of Open Access Journals (Sweden)

    Mehdi Alijani Ardeshir

    2016-09-01

    Full Text Available The importance of the seismic behavior of concrete gravity dams in their safety evaluation and stability is inevitable. Many factors affect the prediction of the behavior of concrete dams such as dam-foundation-reservoir interaction, dam and foundation cracking and also displacement due to fault movement that could causes nonlinear behavior. The aim of this study is nonlinear analysis of concrete gravity dams, including displacement caused by normal fault movement in the dam foundation. For this purpose, dam-foundation-reservoir system is modeled using Lagrangian method and analysis of system is done by finite element method. The coordinate smeared crack model based on the nonlinear fracture mechanics is used for crack modeling in the dam body and foundation. Using two separate method including split node technique and contact element, the fault movement are modeled and the position and angle of fault has been studied. To verify the results, dam crest displacement and crack profile in the body of a concrete gravity dam is presented as an example. The results show that low fault movement causes the cracks in the dam body and could be jeopardizes the stability and safety of concrete dam.

  1. Factors influencing hysteresis characteristics of concrete dam deformation

    Directory of Open Access Journals (Sweden)

    Jia-he Zhang

    2017-04-01

    Full Text Available Thermal deformation of a concrete dam changes periodically, and its variation lags behind the air temperature variation. The lag, known as the hysteresis time, is generally attributed to the low velocity of heat conduction in concrete, but this explanation is not entirely sufficient. In this paper, analytical solutions of displacement hysteresis time for a cantilever beam and an arch ring are derived. The influence of different factors on the displacement hysteresis time was examined. A finite element model was used to verify the reliability of the theoretical analytical solutions. The following conclusions are reached: (1 the hysteresis time of the mean temperature is longer than that of the linearly distributed temperature difference; (2 the dam type has a large impact on the displacement hysteresis time, and the hysteresis time of the horizontal displacement of an arch dam is longer than that of a gravity dam; (3 the reservoir water temperature variation lags behind of the air temperature variation, which intensifies the differences in the horizontal displacement hysteresis time between the gravity dam and the arch dam; (4 with a decrease in elevation, the horizontal displacement hysteresis time of a gravity dam tends to increase, whereas the horizontal displacement hysteresis time of an arch dam is likely to increase initially, and then decrease; and (5 along the width of the dam, the horizontal displacement hysteresis time of a gravity dam decreases as a whole, while the horizontal displacement hysteresis time of an arch dam is shorter near the center and longer near dam surfaces.

  2. SEISMIC RESPONSE OF DAM WITH SOIL-STRUCTURE INTERACTION.

    Science.gov (United States)

    Bycroft, G.N.; Mork, P.N.

    1987-01-01

    An analytical solution to the response of a long trapezoidal-section dam on a foundation consisting of an elastic half-space and subjected to simulated earthquake motion is developed. An optimum seismic design is achieved when the cross section of the dam is triangular. The effect of soil structure interaction is to lower the strain occurring in the dam.

  3. Liberated rivers: lessons from 40 years of dam removal

    Science.gov (United States)

    Marie Oliver; Gordon Grant

    2017-01-01

    In recent decades, dam removal has emerged as a viable national and international strategy for river restoration. According to American Rivers, a river conservation organization, more than 1,100 dams have been removed in the United States in the past 40 years, and more than half of these were demolished in the past decade. This trend is likely to continue as dams age,...

  4. Tenaga Nasional Berhad dam safety and surveillance program

    International Nuclear Information System (INIS)

    Jansen Luis; Zulkhairi Abd Talib

    2006-01-01

    This paper discusses the current practice of dam surveillance, which includes dam monitoring which is a process of visual inspections, measuring, processing, compiling and analyzing dam instrumentation data to determine the performance of a dam. The prime objective of the dam surveillance system is to ensure that any occurrence and development of safety deficiencies and problems are quickly detected, identified, analyzed and the required remedial actions are determined and consequently carried out in due time. In brief, the section is responsible to ensure that the dam monitoring and surveillance works are implemented as per scheduled and in accordance with the requirement and guidelines prepared by the dam designers and in accordance with international commission on large dams, ICOLD. The paper also illustrates and recommends an alternative approach for dam surveillance program using risk management approach, which is currently being actively adopted by some countries like USA, Canada, Australia and etc, towards improving the dam safety management and the decision making process. The approach provides a wider area of opportunity, improvements and benefits particular in the evaluation and modifications to the dam performance and safety. The process provides an effective and efficient tool for the decision makers and engineers through a comprehensive evaluation and a good understanding of the hazards, risks and consequences in relation to dam safety investigations. (Author)

  5. How to manage the cumulative flood safety of catchment dams ...

    African Journals Online (AJOL)

    Dam safety is a significant issue being taken seriously worldwide. However, in Australia, although much attention is being devoted to the medium- to large-scale dams, minimal attention is being paid to the serious potential problems associated with smaller dams, particularly the potential cumulative safety threats they pose ...

  6. 25 CFR 173.16 - Reserved area, Coolidge Dam.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Reserved area, Coolidge Dam. 173.16 Section 173.16... area, Coolidge Dam. No permit for any commercial business or other activity (except boating concessions...-fourths of a mile from the center of the Coolidge Dam, Arizona. ...

  7. Waterbirds at the Theewaterskloof Dam, Western Cape, South Africa ...

    African Journals Online (AJOL)

    With a perimeter of 82km, the Theewaterskloof Dam is the largest dam in the Western Cape. This paper, based on midsummer and mid-winter surveys between 1993 and 2005, assesses the importance of the dam for waterbirds. The median numbers of waterbirds in summer and winter were 3 086 and 1 321, respectively.

  8. Earthquake induced liquefaction analysis of Tendaho earth-fill dam ...

    African Journals Online (AJOL)

    fill dam, which is part of Tendaho Dam and Irrigation Project; the largest irrigation project in Ethiopia to date. The dam is located in the most seismic part of Ethiopia and was originally designed to be founded on potentially liquefiable alluvium ...

  9. Major dams of the United States, Geographic NAD83, USGS (2006) [dams00x020_USGS_2006

    Data.gov (United States)

    Louisiana Geographic Information Center — This map layer portrays major dams of the United States, including Puerto Rico and the U.S. Virgin Islands. The map layer was created by extracting dams 50 feet or...

  10. Microgreffage de quatre espèces ligneuses sahéliennes Acacia senegal, Faidherbia albida, Tamarindus indica et Ziziphus mauritiana) en vue de leur rajeunissement

    OpenAIRE

    Danthu, P.; Hane, B.; Touré, M.; Sagna, P.; Sagna, M.; Bâ, S.; de Troyer, MA.; Soloviev, P.

    2001-01-01

    Micrografting of Four Sahelian Trees (Acacia senegal, Faidherbia albida, Tamarindus indica and Ziziphus mauritiana) with a View to their Rejuvenation. This paper proposes a protocol of rejuvenation of four Sahelian ligneous species : Acacia senegal, Faidherbia albida, Tamarindus indica and Ziziphus mauritian. It consists in aseptically removing a small scion (5-10 mm in length) and in micrografting it on to a seeding grown in vitro used as rootstock. The main elements of success are the age o...

  11. The Spatial Suitable Habitat Model of Acacia decurrens in Mount Merbabu National Park

    Directory of Open Access Journals (Sweden)

    Yoko Untoro

    2017-09-01

    Full Text Available Green wattle (Acacia decurrens is an invasive alien species (IAS found in the Mount Merbabu National Park (TNGMb. This study aim to obtain spatially studies on habitat suitability models of A. decurrens in TNGMb region. In fact, this species became as a high invasive and dominance in the TNGMb and contributes the negative impact to the ecosystem. In addition, the result of this study should be useful for controling activities of A. decurrens. Predictor variables in this research were (altitude, slope, rainfall, air temperature, distance from river, NDVI, NDMI, distance from hiking trail, and distance from burnt area. The survey was conducted with random sampling of presence or absence of A. decurrens by marking the coordinate point of location using GPS. Data analysis in this research was used binary logistic regression enter method. Binary logistic regression involves the data acquisition of the presence and absence of A. decurrens as the y variable, while the predictor variable map as the variable x. The type of spatial distribution of A. decurrens in the TNGMb was identified as clumped. The Nagelkerke R2 values obtained in the model was 39,2%, while 60,8% was explained by other variables were not used in the model. The results of the logistic regression model showed a high percentage of suitability of 64,29%, a medium suitability of 28,57%, and a low suitability of 7.14% then the Implications for controlling activities of A. decurrens in TNGMb could be prioritized in high suitability habitat. Keywords: Acacia decurrens, green wattle, invasive, spatial suitable habitat 

  12. Salt tolerance traits increase the invasive success of Acacia longifolia in Portuguese coastal dunes.

    Science.gov (United States)

    Morais, Maria Cristina; Panuccio, Maria Rosaria; Muscolo, Adele; Freitas, Helena

    2012-06-01

    Salt tolerance of two co-occurring legumes in coastal areas of Portugal, a native species--Ulex europaeus, and an invasive species--Acacia longifolia, was evaluated in relation to plant growth, ion content and antioxidant enzyme activities. Plants were submitted to four concentrations of NaCl (0, 50, 100 and 200 mM) for three months, under controlled conditions. The results showed that NaCl affects the growth of both species in different ways. Salt stress significantly reduced the plant height and the dry weight in Acacia longifolia whereas in U. europaeus the effect was not significant. Under salt stress, the root:shoot ratio (W(R):W(S)) and root mass ratio (W(R):W(RS)) increased as a result of increasing salinity in A. longifolia but the same was not observed in U. europaeus. In addition, salt stress caused a significant accumulation of Na+, especially in U. europaeus, and a decrease in K+ content and K+/Na+ ratio. The activities of antioxidant enzymes were higher in A. longifolia compared to U. europaeus. In A. longifolia, catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2.) activities increased significantly, while ascorbate peroxidase (APX, EC 1.11.1.11) and peroxidase (POX, EC 1.11.1.7) activities remained unchanged in comparison with the control. In U. europaeus, NaCl concentration significantly reduced APX activity but did not significantly affect CAT, GR and POX activities. Our results suggest that the invasive species copes better with salinity stress in part due to a higher rates of CAT and GR activities and a higher K+/Na+ ratio, which may represent an additional advantage when competing with native species in co-occurring salty habitats. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  13. Canker and decline caused by Neofusiccocum parvum on Acacia melanoxylon in Italy

    Directory of Open Access Journals (Sweden)

    Sidoti A

    2016-12-01

    Full Text Available In the spring of 2012, in reforested areas of Peloritani Mountains (Sicily, Italy a severe dieback of Acacia melanoxylon R. Brown was observed. The main symptoms on both young and adults plants consisted of elongated cankers on the trunks and epicormic shoots, wilt of the canopy and dieback interested mostly aged trees. The woody tissues showed browning beyond the cankers. Sapwood and heartwood appeared decayed with a brown to gray-greenish discoloration. One fungal species was consistently isolated from infected woody tissues, which was morphologically attributed to Neofusiccocum sp. The sequencing of the ITS regions of a representative isolate allowed to identify (99% similarity the species Neofusiccocum parvum (Pennycook & Samuels Crous, Slippers and Phillips, teleomorph Botryosphaeria parva Pennycook & Samuels. The pathogenicity tests have reproduced symptoms similar to those observed in the field. N. parvum is the aetiologic agent of mortality of australian blackwood observed in Sicily and to our knowledge this is the first report of this fungus on Acacia melanoxylon. It is a generalist pathogen, cosmopolitan, present in many temperate areas, Mediterranean and subtropical. The older Peloritani Mountains populations of australian blackwood seem particularly susceptible to the pathogen, the latter favored by the lack of silvicultural interventions that generate interspecific and intraspecific competition, as well as the increase and spread of the fungus. To minimize the consequential damage is necessary to adopt sanitation measures that would lower the fungal inoculum and program substitutions of this exotic species with others that have multiple functions suited to environments (e.g., Chestnut or encouraging the establishment and development of native species, such as the holm oak and shrub.

  14. Induction of leafy galls in Acacia mearnsii De Wild seedlings infected by Rhodococcus fascians

    Directory of Open Access Journals (Sweden)

    Marguerite Quoirin

    2004-07-01

    Full Text Available Plantlets of blackwattle (Acacia mearnsii De Wild were inoculated with the bacterium Rhodococcus fascians and cultured in vitro. Leafy galls appeared at the cotyledonary nodes in 75% of the infected plants. The galls were separated from the plants and cultured on a medium containing three-quarters-strength MS salts (Murashige and Skoog, 1962, MS vitamins, 2% sucrose and an antibiotic (cephalothin, supplemented with or without 0.2% activated charcoal. Histological studies conducted from the sixth to the twenty-second day after plant infection revealed the presence of newly formed meristematic centers, first in the axillary region, then on the petioles and lamina of the leaflets around the apical meristem. Approximately 37% of the galls developed one shoot with both concentrations of cephalothin.Plantas recém germinadas de acácia negra (Acacia mearnsii De Wild. foram inoculadas com a bactéria Rhodococcus fascians e cultivadas in vitro. Galhas cobertas por folhas apareceram na altura do nó cotiledonar em 75% das plantas infectadas. As galhas foram separadas das plantas e cultivadas num meio de cultura contendo os sais do meio MS (Murashige e Skoog, 1962 reduzidos a 3/4, as vitaminas do mesmo meio, 2% de sacarose e um antibiótico (cefalotina, adicionado ou não de 0,2% de carvão ativo. Estudos histológicos realizados entre o sexto e o vigésimo segundo dia depois da inoculação, revelaram a presença de centros meristemáticos novos, primeiro nas regiões axilares, em seguida nos pecíolos e limbos dos folíolos ao redor do meristema apical. Aproximadamente 37% das galhas desenvolveram um broto na presença de cefalotina.

  15. Morpho-physiological response of Acacia auriculiformis as influenced by seawater induced salinity stress

    Energy Technology Data Exchange (ETDEWEB)

    Haque, A.; Rahman, M.; Nihad, S.A.I.; Howlader, R.A.; Akand, M.H.

    2016-07-01

    Aim of the study: To evaluate the morpho-physiological changes of Acacia auriculiformis in response to seawater induced salinity stress along with its tolerance limit. Area of study: Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh. Material and methods: Three saline treatments (4, 8, 12 dS m-1) were applied to six-month aged Acacia auriculiformis seedlings from January 2014 to June 2014 and the tap water was used as control treatment. To observe salinity effects, the following parameters were measured by using various established techniques: plant height and leaf number, plant biomass, shoot and root distribution as well as shoot and root density, water uptake capacity (WUC), water saturation deficit (WSD) and water retention capacity (WRC), exudation rate, and cell membrane stability. Main results: Diluted seawater caused a notable reduction in shoot and root distribution in addition to shoot and root density, though plant height, leaf number and plant biomass were found to be decreased to some extent compared to control plants. Water status of the plant also altered when plants were subjected to salinity stress. Nevertheless, membrane stability revealed good findings towards salinity tolerance. Research highlights: Considering the above facts, despite salinity exerts some negative effects on overall plant performance, interestingly the percent reduction value doesn’t exceed 50% as compared to control plants, and the plants were successful to tolerate salinity stress till the end of the experiment (150 days) through adopting some tolerance mechanisms. Abbreviations used: BSMRAU (Bangabandhu Sheikh Mujibur Rahman Agricultural University); RCBD (randomized complete block design); DATI (days after treatment imposition); RWC (relative water content); WUC (water uptake capacity); WSD (water saturation deficit); WRC (water retention capacity); FW (fresh weight); DW (dry weight); TW (turgid weight); ROS (reactive oxygen species). (Author)

  16. Shelterbelt plantations in arid regions. [Acacia tortilis, Prosopis juliflora, Cassia siamea

    Energy Technology Data Exchange (ETDEWEB)

    Muthana, K.D.; Mahander, S.; Mertia, R.S.; Arora, G.D.

    1984-01-01

    Three shelterbelts were planted on sandy soils at the Jodhpur Research Farm in 1973. Belts had 3 rows of trees each and spacing between and within rows was 3 m; they were laid out perpendicular to the wind direction. The length of each belt was 300 m and they were spaced 165 m apart centre to centre. The outside rows were made up of 33 plants each of (a) Acacia tortilis, (b) Prosopis juliflora (Israel variety) and (c) Cassia siamea planted on either side of the belts randomly in the paterns abc, bca and cab. The centre rows were planted with Azadirachta indica, Albizzia (Albizia) lebbek and Eucalyptus camaldulensis respectively in the 1st, 2nd and 3rd shelterbelts. The shelterbelts were easily established and grew well. Grain yield of bajra sown between the belts increased with distance from them reaching a maximum at 25 X belt height and then declining. Average yield between the belts was higher than in control plots. Consumptive water use and water use efficiencies were less near the 1st shelterbelt (leeward side) and increased away from it, again reaching maximum at 25 X belt height. Mean air temperature 1-2m above ground level was 0.1-0.2 degrees C higher on leeward than on windward sides of shelterbelts in the summer months, and 0-0.1 degrees higher in the monsoon months. Pan evaporation on the leeward side was reduced by 8% in the summer and 6% in the monsoon months. Belts of C. siamea and Acacia tortilis were more effective in reducing wind speed than those of P. juliflora (which grew least of all species).

  17. Morpho-physiological response of Acacia auriculiformis as influenced by seawater induced salinity stress

    Directory of Open Access Journals (Sweden)

    Md Anamul Haque

    2016-12-01

    Full Text Available Aim of the study: To evaluate the morpho-physiological changes of Acacia auriculiformis in response to seawater induced salinity stress along with its tolerance limit. Area of study: Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh. Material and methods: Three saline treatments (4, 8, 12 dS m-1 were applied to six-month aged Acacia auriculiformis seedlings from January 2014 to June 2014 and the tap water was used as control treatment. To observe salinity effects, the following parameters were measured by using various established techniques: plant height and leaf number, plant biomass, shoot and root distribution as well as shoot and root density, water uptake capacity (WUC, water saturation deficit (WSD and water retention capacity (WRC, exudation rate, and cell membrane stability. Main results: Diluted seawater caused a notable reduction in shoot and root distribution in addition to shoot and root density, though plant height, leaf number and plant biomass were found to be decreased to some extent compared to control plants. Water status of the plant also altered when plants were subjected to salinity stress. Nevertheless, membrane stability revealed good findings towards salinity tolerance. Research highlights: Considering the above facts, despite salinity exerts some negative effects on overall plant performance, interestingly the percent reduction value doesn’t exceed 50% as compared to control plants, and the plants were successful to tolerate salinity stress till the end of the experiment (150 days through adopting some tolerance mechanisms. Additional key words: Salt stress; halophytes; growth parameters; WUC; exudation rate; membrane stability. Abbreviations used: BSMRAU (Bangabandhu Sheikh Mujibur Rahman Agricultural University; RCBD (randomized complete block design; DATI (days after treatment imposition; RWC (relative water content; WUC (water uptake capacity; WSD (water saturation deficit; WRC (water retention

  18. Acacia tortilis

    African Journals Online (AJOL)

    Gloria

    [18] - S. CISSÉ, Thèse de doctorat en Géologie Appliquée, Université Cheikh Anta Diop, Faculté des. Sciences et Techniques, Dakar, Sénégal, (2000). [19] - F. T. NGARYO, E.L. AKPO, V. GOUDIABY, A. K. BADIATTE, J. LOGBO, M. DIOUF, Annales de l'Université de N'Djaména,Série C N°2, (2007) 27-41. [20] - J. KENGUE ...

  19. Ecological Aspect of Dam Design for Flood Regulation and Sustainable Urban Development

    Directory of Open Access Journals (Sweden)

    Badenko Vladimir

    2016-01-01

    Full Text Available Many floodplains are excluded from urban development because the floods cause considerable damage to people’s lives and properties. This requires the development of new approaches to flood management and mitigation for support sustainable urban development. In present study as the measures for mitigation of flash floods, the regulation of river flow by the system of detention reservoirs for flood diversion with dams, which do not need any operation management, are analyzed concerning of Far East region of Russia. The main objective of this paper is to develop a method for analysis how the dam site selection meets the environmental criterion. The method to justify a selection of self-regulated flood dam parameters, primarily a height of a dam and its location on a water stream, providing minimization of impact on the environment have been developed. The result for Selemdzha river basin in Far East monsoon region of Russian Federation is analyzed. The result shows the robustness of the method.

  20. DAM-LAKEFRONT PLAZA: Revitalization of an Agriculture Reservoir Dam in Kashar-Tirana/Albania

    Directory of Open Access Journals (Sweden)

    Valbona Koçi

    2014-12-01

    Full Text Available The Dam-Lakefront Plaza in Kashar-Tirana/Albania is a research project that proposes not only the re-consideration and reinforcement of the artificial Reservoirs Dams built during Socialism in Albania, but envisions the maintenance of dams and revitalization of the lakeside area promoting the public-private collaboration. In addition, it envisions the generation of qualitative and lively public spaces in sub-urban areas as well. Admitting the artificial lakes as specific nodes of man-made infrastructure in the landscape, and consequently the dams (together with the drainage channels as important hydrotechnic elements of the flood protection infrastructure, this research intends to elaborate on one type of landscape infrastructure - the vertical screens, offering a mediation between the natural and built landscape.

  1. Dam water quality study. Report to Congress

    International Nuclear Information System (INIS)

    1989-05-01

    The objective of the report is to identify water quality effects attributable to the impoundment of water by dams as required by Section 524 of the Water Quality Act of 1987. The document presents a study of water quality effects associated with impoundments in the U.S.A

  2. Geologic Conceptual Model of Mosul Dam

    Science.gov (United States)

    2007-09-01

    geomechanical characteristics or geotechnical properties. As an example, if the locations and depths of zones of high grout-take are known, these zones can...Dam safety Foundation grout Geologic model GIS Gypsum Hydrogeology Iraq geology Karst 3-D modeling 16. SECURITY CLASSIFICATION

  3. living in Kapulukaya Dam Lake (Kirikkale, Turkey)

    African Journals Online (AJOL)

    GREGORY

    2010-08-23

    Aug 23, 2010 ... Key words: Esox lucius, Northern pike, breeding, Kapulukaya Dam Lake, Turkey. INTRODUCTION. Northern pike (Esox lucius) from Esocidae family is a commonly hunted fish due to its tasty meat. It generally lives in lakes but it is frequently seen in rivers and stream. Although it is known as a freshwater ...

  4. Will We. . .? Thai Dam Resource Book.

    Science.gov (United States)

    Murphy, Richard, Ed.; And Others

    This resource book is intended as an aid to persons working with Thai Dam refugees. To help the language teacher, some differences between Lao and English are discussed, specifically tonal inflections, positioning, declension of pronouns, conjugation of verbs, interrogatives, classifiers and predicate adjectives. An outline of cultural differences…

  5. Dam tot damloop : economische en maatschappelijke waarde

    NARCIS (Netherlands)

    de Nooij, Michiel; Horsselenberg, Peter

    2014-01-01

    Ruim 36.757 lopers (op de hoofdafstand!) en 115.000 bezoekers langs het parcours van het centrum van Amsterdam naar het centrum van Zaanstad, maakt de Dam tot damloop een groot evenement (het grootste hardloop evenement van Nederland) met een flinke impact op de (lokale) samenleving en economie. Dit

  6. Rehabilitation of the John Hart dam

    International Nuclear Information System (INIS)

    Cathcart, D.S.

    1989-01-01

    The largest and most recent rehabilitation project undertaken by British Columbia Hydro involves the John Hart Dam on the Campbell River on Vancouver Island. This area has the potential for large earthquake events, with an earthquake with a 7.3 rating on the Richter scale occurring as construction was underway in 1946. Investigation showed that the dam and foundations were liable to liquify under low seismic loading, and the area downstream is now well developed and inhabited. Taking the 120 MW power plant out of operation would jeopardize the power supply to northern Vancouver Island, so it was decided to take immediate steps to stabilize the most sensitive areas and then to rehabilitate the dam to an acceptable level of earthquake resistance while maintaining the reservoir at normal level with the power plant in operation. Using innovative engineering techniques and careful monitoring, the project, which included foundation improvement under existing structures and virtual rebuilding of the earthdam, was completed without lowering the reservoir. In spite of the very restrictive environmental constraints, the work was done without unacceptable environmental impact or adverse public reaction. Costs were $24 million, slightly under budget. All instrumentation has been monitored on a regular basis and the performance of the dam is satisfactory. 7 figs

  7. Resilience scales of a dammed tropical river

    Science.gov (United States)

    Calamita, Elisa; Schmid, Martin; Wehrli, Bernhard

    2017-04-01

    Artificial river impoundments disrupt the seasonality and dynamics of thermal, chemical, morphological and ecological regimes in river systems. These alterations affect the aquatic ecosystems in space and time and specifically modify the seasonality and the longitudinal gradients of important biogeochemical processes. Resilience of river systems to anthropogenic stressors enables their recovery along the flow path; however little is known about the longitudinal distance that rivers need to partially restore their physical, chemical and biological integrity. In this study, the concept of a "resilience scale" will be explored for different water quality parameters downstream of Kariba dam, the largest artificial lake in the Zambezi basin (South-East Africa). The goal of this project is to develop a modelling framework to investigate and quantify the impact of large dams on downstream water quality in tropical context. In particular, we aim to assess the degree of reversibility of the main downstream alterations (temperature, oxygen, nutrients) and consequently the quantification of their longitudinal extent. Coupling in-situ measurements with hydraulic and hydrological parameters such as travel times, will allow us to define a physically-based parametrization of the different resilience scales for tropical rivers. The results will be used for improving future dam management at the local scale and assessing the ecological impact of planned dams at the catchment scale.

  8. Physicochemical characteristics of undrainable water dams utilized ...

    African Journals Online (AJOL)

    pH, electro-conductivity and total dissoved solutes (TDS) were measured in-situ from three reservoirs (Gathathini, Lusoi and Kianda dams) differing in their habitat characteristics. Water samples were collected for determination of the ionic concentartions of the reservoirs. Water quality status differed markedly between sites, ...

  9. Can Dams and Reservoirs Cause Earthquakes?

    Indian Academy of Sciences (India)

    FAULT. Triggering of Earthquakes. Ramesh Chander. No! Not on their own. But, stresses and pore pressure due to natural causes may already have accumulated in crustal rocks at some dam sites to near critical levels for fresh faulting or renewed slip on nearby pre-existing faults. The stresses and pore pressure induced ...

  10. Monitoring the structural integrity of large concrete dams: the case of Cabril dam, Portugal

    OpenAIRE

    Oliveira, S.; Ferreira, I.; Berberan, A. L.; Mendes, P.; Boavida, J.; Baptista, B.

    2010-01-01

    The safety control of large dams under static and dynamic loads, involving observation data and numerical modeling, is now one of the challenges of structural engineering. The complexity of the dam-reservoir-foundation geometry, the presence of different types of discontinuities, the water-structure interaction, the influence of thermal and water level variations, the development of deterioration processes over time and the occurrence of exceptional events such as major floods or earthquakes,...

  11. National Dam Safety Program. Raintree Lake Dam (MO 20388), Missouri - Kansas City Basin, Cass County, Missouri. Phase I Inspection Report.

    Science.gov (United States)

    1979-05-01

    report was pepared under the National Program of Inspection of Non-Federal Dams. This report assesses the general condition of the dam withprespect...raise any serious questions relating to the safety of the dam or iden- tify any serious dangers that would require a Phase II investigation. e. Seismic

  12. Experimental research on the dam-break mechanisms of the Jiadanwan landslide dam triggered by the Wenchuan earthquake in China.

    Science.gov (United States)

    Xu, Fu-gang; Yang, Xing-guo; Zhou, Jia-wen; Hao, Ming-hui

    2013-01-01

    Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation.

  13. 78 FR 60271 - Hollow Dam Power Company; Ampersand Hollow Dam Hydro, LLC; Notice of Application for Transfer of...

    Science.gov (United States)

    2013-10-01

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 6972-032] Hollow Dam Power Company; Ampersand Hollow Dam Hydro, LLC; Notice of Application for Transfer of License, and Soliciting Comments and Motions To Intervene On September 10, 2013, Hollow Dam Power Company (transferor) and...

  14. National Dam Safety Program. Lake Frederick Dam (Inventory Number NY 769), Orange County, New York. Phase 1 Inspection Report

    Science.gov (United States)

    1980-03-11

    COMPUTATIONSF F . OTHER DATA LAL M- PHASE I REPORT - NATIONAL DAM SAFETY PROGRAMA _ Name of Dam: LAKE FREDERICK DAM (I.D. NO. 769) V - State Located: NEW YORK... abc -ut 230 feet to the right of the spiliway. The conduit runs = underground and outfalls about 75 feet downstream frm the toe of the dar; the

  15. Experimental Research on the Dam-Break Mechanisms of the Jiadanwan Landslide Dam Triggered by the Wenchuan Earthquake in China

    Science.gov (United States)

    Xu, Fu-gang; Yang, Xing-guo; Hao, Ming-hui

    2013-01-01

    Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation. PMID:23844387

  16. Phosphate accumulation in farm dam sediments

    International Nuclear Information System (INIS)

    Ruan, H.D.; Gilkes, R.J.

    1998-01-01

    Full text: Large amounts of phosphate are applied to agricultural regions in Australia each year. Phosphate is incorporated into organic materials, sorbed onto the surface of clay minerals, carbonates, iron oxides/hydroxides and other colloids or dissolved in soil solution. Phosphate in soil solution may leach into dam, or absorbed and particulate phosphate may be washed into dams during soil erosion and eventually accumulate in sediments. Variable and sometimes high concentrations of phosphate in water and sediments occur in farm dams in the York area of Western Australia. Phosphate accumulation in farm dam sediments (O to about 2 cm) was investigated using chemical analysis and X-ray diffraction. Concentrations of phosphorus up to 5 ppm in water and 1100 ppm in sediment were observed. The results of this study indicate that the amounts of total, organic and inorganic phosphate in sediment are approximately equal and are linearly related the dissolved phosphate concentration in dam water. High concentrations of nitrogen also exit in sediments and are closely related to the phosphate content of sediment presumably reflecting the high content of organic matter in sediments, ranging from 3 to 7% C. The concentration of phosphate in sediments is closely related to the organic matter concentration measured by LECO CHN analyser. X-ray diffraction patterns show that clay minerals in sediments consist of minor to large amounts of smectite and kaolinite, minor to moderate amounts of illite, mica and feldspars. Minor amounts of calcite and iron oxides were present only in a few samples. Clay minerals and iron oxides have moderate to high phosphate sorption capacities because the reactive sites on crystal surfaces and their high surface area. Thus colloidal minerals, organic materials and organo-mineral complexes may provide reactive sites for phosphate sorption

  17. Measuring Inclinations in Cabril Dam with an Optoelectronic Sensor

    OpenAIRE

    Henriques, M. J.; Lima, J. N.; Oliveira, S.

    2012-01-01

    A high precision inclinometer was placed at the top gallery of Cabril dam, the highest dam in Portugal (132 m). Cabril dam has been presenting, since the first filling of the reservoir (1953), some horizontal cracks in the central upper zone. The dual axis inclinometer, with a recording measuring rate of 1 Hz, was installed for two days; during the same period a digital thermometer, for recording air temperatures, was placed next to the downstream face of the dam. The dam remained under norma...

  18. Dam safety status in New South Wales (NSW), Australia

    International Nuclear Information System (INIS)

    Himsley, N.

    1996-01-01

    The design, operation and safety of some 250 large water supply/irrigation/hydroelectric/mine tailings dams in New South Wales (NSW) rest upon legislation enacted by the NSW Government in 1978. This paper provides a description of the details surrounding the evolution of the Act, problems that the Act was enacted to resolve, and practices and requirements for prescribed dam owners relating to dam design, construction, operation and maintenance, upgrading, decommissioning, and activities around dams. Future concerns, relating to pressures for economic rationalization, environmental concerns, public participation in decision making, dam ageing, and advancement of technology also have been addressed. 3 refs., 1 tab

  19. Proceeding of the public safety around dams conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The Canadian Dam Association hosted the Public Safety Around Dams workshop in which presentations were given in the morning to describe the different measures and methods implemented by the Ontario Ministry of Natural Resources, Ontario Power Generation and others to improve safety around dams. In the afternoon, the participants toured the Auburn and Lakefield dams and facilities to view the infrastructures and equipment. A roundtable discussion concluded the day. Following this workshop, a Public Safety Around Dams group was created on the social network site, LinkedIn. This conference featured 6 presentations, 3 of which have been catalogued separately for inclusion in this database.

  20. Variasi Genetik Sifat-sifat Kayu Uji Keturunan Acacia Mangium Umur 5 Tahun Di Wonogiri, Jawa Tengah (Genetic Variation of Wood Properties in Progeny Trial of Acacia Mangium on 5 Years Old in Wonogiri, Central Java)

    OpenAIRE

    Susanto, Mudji; Naiem, Mohammad; Hardiyanto, Eko Bhakti; Prayitno, T.A

    2013-01-01

    First generation (F-1) of progeny trial of Acacia mangium originated from Papua New Guinea and Queensland-Australia was established in Wonogiri, Central Java on December 1993. The tree selection within family were carried out base on growth characteristic, whereas the wood property traits were not included. The objective of this research is to find the effect of provenance or family in variation of diameter and wood properties of`A. mangium in the trial in 5 years old. The results showed ...

  1. Seed oil composition of Acacia nilotica (L. Delile from Iran / Skład oleju z nasion Acacia nilotica (L. Delile rosnącej w Iranie

    Directory of Open Access Journals (Sweden)

    Abbasian Karim

    2016-03-01

    Full Text Available Wstęp: Acacia nilotica (L. Delile należy do rodziny Fabaceae, podrodziny Mimosoideae; otrzymuje się z niej gumę arabską. W południowym Iranie są spożywane pieczone młode strąki i nasiona tej rośliny Cel: Badano skład oleju z dojrzałych nasion A. nilotica zebranych z naturalnych stanowisk na południu Iranu w celu określenia jego przydatności do spożycia przez ludzi i zwierzęta. Metody: Wyekstrahowany olej analizowano metodą chromatografii gazowej sprzężonej ze spektrometrią mas (GC/MS. Wyniki: Zawartość oleju w jadalnych nasionach wynosiła 3.4% (v/w świeżej masy. Olej zawierał rzadko spotykany fitosterol, sześć kwasów tłuszczowych, dziewięć węgolwodorów i jeden diterpenoid; związki te stanowiły łącznie około 83.5% oleju. Głównymi składnikami oleju były: fitosterol, 26-ethylcholesta-5,25(Z-dien-3.β-ol (20.8% oraz nasycone i nienasycone kwasy tłuszczowe. Zawartość pozostałych składników nie przekroczyła 5%. Wniosek: Olej z nasion omawianego gatunku może być nowym naturalnym środkiem odżywczym dla ludzi.

  2. Effects of flow alteration on Apple-ring Acacia (Faidherbia albida) stands, Middle Zambezi floodplains, Zimbabwe

    NARCIS (Netherlands)

    Gope, E.T.; Sass-Klaassen, U.G.W.; Irvine, K.; Beevers, L.; Hes, E.M.

    2015-01-01

    The impounding of the Zambezi River by Kariba dam has regulated the river discharge of the Middle Zambezi river. This has been implicated in the failure of regeneration of Faidherbia albida in the downstream flood plain. This study aimed (1) to assess the effect of the altered flow regime of the

  3. Dam failure analysis for the Lago El Guineo Dam, Orocovis, Puerto Rico

    Science.gov (United States)

    Gómez-Fragoso, Julieta; Heriberto Torres-Sierra,

    2016-08-09

    The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, completed hydrologic and hydraulic analyses to assess the potential hazard to human life and property associated with the hypothetical failure of the Lago El Guineo Dam. The Lago El Guineo Dam is within the headwaters of the Río Grande de Manatí and impounds a drainage area of about 4.25 square kilometers.The hydrologic assessment was designed to determine the outflow hydrographs and peak discharges for Lago El Guineo and other subbasins in the Río Grande de Manatí hydrographic basin for three extreme rainfall events: (1) a 6-hour probable maximum precipitation event, (2) a 24-hour probable maximum precipitation event, and (3) a 24-hour, 100-year recurrence rainfall event. The hydraulic study simulated a dam failure of Lago El Guineo Dam using flood hydrographs generated from the hydrologic study. The simulated dam failure generated a hydrograph that was routed downstream from Lago El Guineo Dam through the lower reaches of the Río Toro Negro and the Río Grande de Manatí to determine water-surface profiles developed from the event-based hydrologic scenarios and “sunny day” conditions. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC–HMS) and Hydrologic Engineering Center’s River Analysis System (HEC–RAS) computer programs, developed by the U.S. Army Corps of Engineers, were used for the hydrologic and hydraulic modeling, respectively. The flow routing in the hydraulic analyses was completed using the unsteady flow module available in the HEC–RAS model.Above the Lago El Guineo Dam, the simulated inflow peak discharges from HEC–HMS resulted in about 550 and 414 cubic meters per second for the 6- and 24-hour probable maximum precipitation events, respectively. The 24-hour, 100-year recurrence storm simulation resulted in a peak discharge of about 216 cubic meters per second. For the hydrologic analysis, no dam failure conditions are

  4. Rehabilitation of an 80 year old Ambursen dam

    International Nuclear Information System (INIS)

    Matich, M.A.J.; Eddy, W.; Tyler, R.J.; Budgell, W.S.

    1999-01-01

    The Abitibi-Price Inc. hydroelectric facility at Bishop's Falls, NF, as built comprised an earth dam, a hollow concrete Ambursen type dam, and intake works at the powerhouse, as the main retaining structures. On January 13, 1983, an unprecedented flood occurred in the region which completely destroyed the earth dam connecting the powerhouse building to the riverbank of the town of Bishop's Falls. Major items of remedial work included a new earth dam and a new gated spillway. The flood did not result in any serious damage to the Ambursen dam, but exposure of the dam to the elements did result in stress which required rehabilitation. The favourable performance of the dam through a long service life in a northern Canadian climatic setting was a significant factor in the decision that the structure could be used without serious modification for at least 50 years. The evaluation of the dam, together with the distress experienced as a result of the flood and the remedial action applied are described as a case history. On the basis of condition and stability analysis, it was considered that repairs consisting of a new lining on the upstream side, grouting of deformation related cracking in the interior of the dam, and shotcrete treatment to the exterior of the downstream side, would give the dam a long service life. These remedial actions were applied, and the performance of the dam to date has met design expectations. 26 refs., 10 figs

  5. Dynamic response of Masjed-Soleyman rockfill dam

    Energy Technology Data Exchange (ETDEWEB)

    Jafarzadeh, F. [Sharif Univ. of Technology, Tehran (Iran, Islamic Republic of)]|[Moshanir Power Eng. Co., Tehran (Iran, Islamic Republic of)

    2004-07-01

    Earth dams are large three-dimensional non-homogeneous structures constructed from inelastic materials. One of the main mechanical characteristics of earth dams is the nonlinear behaviour of soil materials under large strains such as those induced by earthquakes. In order to determine the seismic safety of earth dams, it is necessary to predict the dynamic response of embankment dams to earthquake motions. This study examined the response of the newly constructed, 177 metre high Masjed-Soleyman rock filled dam located in a seismic region of southwest Iran. This paper described the dam site geology and seismicity, dam instrumentation, response to ground motions, and numerical simulations. Some earthquakes which registered more than 5 on the Richter scale occurred near the dam site just after impounding. Accelerometers at the crest and downstream shell recorded the response of the dam body. This paper presented the time and frequency history of the dam response. Dynamic properties such as fundamental frequencies of the dam were estimated using 2 constitutive models called equivalent linear and elastoplastic nested surface models. Good agreement was noted between recorded characteristics and numerical analysis. 5 refs., 1 tab., 10 figs.

  6. Seismic failure modes and seismic safety of Hardfill dam

    Directory of Open Access Journals (Sweden)

    Kun Xiong

    2013-04-01

    Full Text Available Based on microscopic damage theory and the finite element method, and using the Weibull distribution to characterize the random distribution of the mechanical properties of materials, the seismic response of a typical Hardfill dam was analyzed through numerical simulation during the earthquakes with intensities of 8 degrees and even greater. The seismic failure modes and failure mechanism of the dam were explored as well. Numerical results show that the Hardfill dam remains at a low stress level and undamaged or slightly damaged during an earthquake with an intensity of 8 degrees. During overload earthquakes, tensile cracks occur at the dam surfaces and extend to inside the dam body, and the upstream dam body experiences more serious damage than the downstream dam body. Therefore, under the seismic conditions, the failure pattern of the Hardfill dam is the tensile fracture of the upstream regions and the dam toe. Compared with traditional gravity dams, Hardfill dams have better seismic performance and greater seismic safety.

  7. Scavenging remazol brilliant blue R dye using microwave-assisted activated carbon from acacia sawdust: Equilibrium and kinetics studies

    Science.gov (United States)

    Yusop, M. F. M.; Aziz, H. A.; Ahmad, M. A.

    2017-10-01

    This work explores the feasibility of microwave-assisted acacia wood based activated carbon (AWAC) for remazol brilliant blue R (RBBR) dye removal from synthetic wastewater. Acacia wood (AW) was impregnated with potassium hydroxide (KOH) and heated using microwave, resulting tremendously high fixed carbon content, surface area, total pore volume and adsorption capacity of 81.14%, 1045.56m2/g, 0.535cm3/g and 263.16mg/g respectively. Batch study conducted divulged an increasing trend in RBBR uptake when initial RBBR concentration and contact time were increased. pH study revealed that RBBR adsorption was best at acidic condition. Langmuir isotherm model fitted well the adsorption equilibrium data while the adsorption kinetic was found to follow the pseudo-second-order kinetic model.

  8. Plio-Pleistocene history and phylogeography of Acacia senegal in dry woodlands and savannahs of sub-Saharan tropical Africa: evidence of early colonisation and recent range expansion.

    Science.gov (United States)

    Odee, D W; Telford, A; Wilson, J; Gaye, A; Cavers, S

    2012-12-01

    Drylands are extensive across sub-Saharan Africa, socio-economically and ecologically important yet highly sensitive to environmental changes. Evolutionary history, as revealed by contemporary intraspecific genetic variation, can provide valuable insight into how species have responded to past environmental and population changes and guide strategies to promote resilience to future changes. The gum arabic tree (Acacia senegal) is an arid-adapted, morphologically diverse species native to the sub-Saharan drylands. We used variation in nuclear sequences (internal transcribed spacer (ITS)) and two types of chloroplast DNA (cpDNA) markers (PCR-RFLP, cpSSR) to study the phylogeography of the species with 293 individuals from 66 populations sampled across its natural range. cpDNA data showed high regional and rangewide haplotypic diversity (h(T(cpSSR))=0.903-0.948) and population differentiation (G(ST(RFLP))=0.700-0.782) with a phylogeographic pattern that indicated extensive historical gene flow via seed dispersal. Haplotypes were not restricted to any of the four varieties, but showed significant geographic structure (G(ST(cpSSR))=0.392; R(ST)=0.673; R(ST)>R(ST) (permuted)), with the major division separating East and Southern Africa populations from those in West and Central Africa. Phylogenetic analysis of ITS data indicated a more recent origin for the clade including West and Central African haplotypes, suggesting range expansion in this region, possibly during the Holocene humid period. In conjunction with paleobotanical evidence, our data suggest dispersal to West Africa, and across to the Arabian Peninsula and Indian subcontinent, from source populations located in the East African region during climate oscillations of the Plio-Pleistocene.

  9. Plio-Pleistocene history and phylogeography of Acacia senegal in dry woodlands and savannahs of sub-Saharan tropical Africa: evidence of early colonisation and recent range expansion

    Science.gov (United States)

    Odee, D W; Telford, A; Wilson, J; Gaye, A; Cavers, S

    2012-01-01

    Drylands are extensive across sub-Saharan Africa, socio-economically and ecologically important yet highly sensitive to environmental changes. Evolutionary history, as revealed by contemporary intraspecific genetic variation, can provide valuable insight into how species have responded to past environmental and population changes and guide strategies to promote resilience to future changes. The gum arabic tree (Acacia senegal) is an arid-adapted, morphologically diverse species native to the sub-Saharan drylands. We used variation in nuclear sequences (internal transcribed spacer (ITS)) and two types of chloroplast DNA (cpDNA) markers (PCR-RFLP, cpSSR) to study the phylogeography of the species with 293 individuals from 66 populations sampled across its natural range. cpDNA data showed high regional and rangewide haplotypic diversity (hT(cpSSR)=0.903–0.948) and population differentiation (GST(RFLP)=0.700–0.782) with a phylogeographic pattern that indicated extensive historical gene flow via seed dispersal. Haplotypes were not restricted to any of the four varieties, but showed significant geographic structure (GST(cpSSR)=0.392; RST=0.673; RST>RST (permuted)), with the major division separating East and Southern Africa populations from those in West and Central Africa. Phylogenetic analysis of ITS data indicated a more recent origin for the clade including West and Central African haplotypes, suggesting range expansion in this region, possibly during the Holocene humid period. In conjunction with paleobotanical evidence, our data suggest dispersal to West Africa, and across to the Arabian Peninsula and Indian subcontinent, from source populations located in the East African region during climate oscillations of the Plio-Pleistocene. PMID:22929152

  10. Individual based, long term monitoring of acacia trees in hyper arid zone: Integration of a field survey and a remote sensing approach

    Science.gov (United States)

    Isaacson, Sivan; Blumberg, Dan G.; Ginat, Hanan; Shalmon, Benny

    2013-04-01

    Vegetation in hyper arid zones is very sparse as is. Monitoring vegetation changes in hyper arid zones is important because any reduction in the vegetation cover in these areas can lead to a considerable reduction in the carrying capacity of the ecological system. This study focuses on the impact of climate fluctuations on the acacia population in the southern Arava valley, Israel. The period of this survey includes a sequence of dry years with no flashfloods in most of the plots that ended in two years with vast floods. Arid zone acacia trees play a significant role in the desert ecosystem by moderating the extreme environmental conditions including radiation, temperature, humidity and precipitation. The trees also provide nutrients for the desert dwellers. Therefore, acacia trees in arid zones are considered to be `keystone species', because they have major influence over both plants and animal species, i.e., biodiversity. Long term monitoring of the acacia tree population in this area can provide insights into long term impacts of climate fluctuations on ecosystems in arid zones. Since 2000, a continuous yearly based survey on the three species of acacia population in seven different plots is conducted in the southern Arava (established by Shalmon, ecologist of the Israel nature and parks authority). The seven plots representing different ecosystems and hydrological regimes. A yearly based population monitoring enabled us to determine the mortality and recruitment rate of the acacia populations as well as growing rates of individual trees. This survey provides a unique database of the acacia population dynamics during a sequence of dry years that ended in a vast flood event during the winter of 2010. A lack of quantitative, nondestructive methods to estimate and monitor stress status of the acacia trees, led us to integrate remote sensing tools (ground and air-based) along with conventional field measurements in order to develop a long term monitoring of acacia

  11. Efek Tinggi Muka Air Tanah dan Pemupukan terhadap Emisi Co2 pada Tanah Gambut dengan Serasah Daun Akasia (Acacia Crassicarpa)

    OpenAIRE

    Sianturi, Merry; ', Wawan; ', Wardati

    2014-01-01

    Indonesia has the largest peatland among the tropical countries which are spread in Sumatra mainly in province of Riau, Kalimantan and Papua. This study aims to know the effect of water level and fertilization N, P, K on CO2 emissions in peatland with litter of akasia (Acacia crassicarpa). This research was conducted in the Screen House, Plant Laboratory Faculty of Agriculture, University of Riau, from July to December 2013. This research was conducted experimentally using completely randomiz...

  12. Long-term Monitoring of Ecological and Geomorphic Adjustments to Dam Removal in an Upland Mesic Catchment

    Science.gov (United States)

    Magilligan, F. J.; Nislow, K. H.; Doyle, H.; Kynard, B.; Dietrich, J. T.

    2015-12-01

    Although more than 1,100 dams have been removed nationally, only 10% have any post-removal assessments with Dam in central MA, we sampled geomorphic parameters in Amethyst Brook (23 km2) pre-removal and in each subsequent post-removal year through 2015. We combined these geomorphic assessments with quantitative electrofishing surveys of stream fish richness and abundance above and below the dam and with visual surveys of native anadromous Sea lamprey (Petromyzon marinus) nest sites. Post-removal assessments were complicated by 2 events: upstream knickpoint migration exhumed an older wooden crib dam 120 m upstream of the former dam, and the occurrence of a 20-yr RI flood 6 months after removal. Process-based erosion dominated in the initial post-removal months with significant bed erosion and knickpoint migration occurring through the former reservoir and upstream to the exhumed crib dam that now acts as a grade control. Similar to other removals, the bed aggraded (20 cm) and fined (~50%) downstream in the initial year, with subsequent coarsening (~ 10-20%) in Years 2 and 3, but with D50 still significantly finer than the pre-removal armored bed. The initial fining and subsequent coarsening, unlike previous studies, does not reflect erosion of former reservoir fill but represents the re-connected upstream sediment supply. Ecologically, our monitoring has further underscored the importance of restoring sediment supply and removing barriers to movement to the diversity and abundance of the native fish assemblage. The observed fining has had major implications for Sea lamprey that require fine gravel for spawning, allowing them to spawn in previously unoccupied below-dam sections. Dam removal has also allowed three additional native species to rapidly expand their upstream distribution up to, but not beyond the exhumed dam. Downstream abundances of some species in the first year were markedly reduced in dam-adjacent sections in response to the major geomorphic changes

  13. Hydrobiological aspects of Paraibuna and Paraitinga dams. Sao Paulo, with emphasis on phytoplankton community

    International Nuclear Information System (INIS)

    Matos, Janara de Camargo

    2010-01-01

    The inland waters are less on the Earth's surface and are extremely important for the survival of living things, why the concern for quality increases daily. The dams Paraibuna and Paraitinga, located in Paraibuna city, state of Sao Paulo, totaling 224 km 2 of extension of water surface, with the current function of generating electricity. In order to analyze the water quality of these dams, this paper presents a diagnostic physical, chemical, and biological, which was used in the phytoplankton community and calculation of quality indexes. Four samples were taken at nine sampling points distributed along the dams. The physical and chemical analysis of water showed low concentrations of nutrients such as nitrate (mean 0,42 ± 0,23 mg.L -1 and phosphate ( -1 ). Most metals and trace elements analyzed were within the limit established by federal law. The element phosphorus (mean 0,0293 ± 0,0153 mg.L -1 ) is presented above the values established by CONAMA Resolution 357/05 (0,020 mg.L -1 ) on all sampling points in the month of May, but this fact did not seem to influence the phytoplankton amount. High levels of dissolved oxygen and transparency, low levels of turbidity, conductivity and dissolved solids, pH close to neutrality, together with high diversity and low dominance of phytoplankton, with a predominance of green algae, showed that the dams still retain features of aquatic environment preserved, which suffer little influence of anthropogenic factors. However, the presence, even at low densities, of cyanobacteria and the existence of plantations and livestock activities in the borders of these dams deserve special attention in terms of their correct management to not become harmful factors to the quality of those waters. (author)

  14. Initial Infection of Falcataria moluccana Leaves and Acacia mangium Phyllodes by Uromycladium tepperianum Fungi in a Laboratory Trial

    Directory of Open Access Journals (Sweden)

    Siti Muslimah Widyastuti

    2014-01-01

    Full Text Available Sengon is a fast growing species that is cultivated widely in Indonesia. Lately, sengon is severely attacked by fungus Uromycladium tepperianum that causing gall rust disease. It is also known to attack various types of acacia. This study aims to determine the fungal infection process U. tepperianum on sengon leaves and the possibility of infection on Acacia mangium in the laboratory trial. Leave samples and fungal pathogen teliospores obtained from Cangkringan, Sleman, Yogyakarta. Several approach procedures conducted to achieve these objectives were: (1 identification of diseased trees, (2 collecting samples of diseased leaves, branches, twigs, and stems, and (3 artificial inoculation and investigating the infection process of U. tepperianum teliospores in the laboratory. The results showed that the process of infection in sengon started by teliospores germination and germ tube formation. Successive germ tube forming penetration pegs. In the plant tissue, the penetration peg formed hypha and further developed into intracellular and intercellular hyphae. The artificial inoculation on A. mangium leaf surface showed few spores can germinate. However, none of them managed to penetrate. Keywords: Uromycladium tepperianum, sengon, acacia, gall rust, infection DOI: 10.7226/jtfm.19.3.187

  15. Properties of resorcinol-tannin-formaldehyde copolymer resins prepared from the bark extracts of Taiwan acacia and China fir.

    Science.gov (United States)

    Lee, Wen-Jau; Lan, Wei-Chuan

    2006-01-01

    Resorcinol-tannin-formaldehyde copolymer resins (RTF) were prepared by using the bark extracts of Taiwan acacia (Acacia confusa) and China fir (Cunninghamia lanceolata) to substitute part of the resorcinol. From the results, the content of reactive phenolic materials in Taiwan acacia and China fir bark extracts were 51.6% and 46.5%, respectively. Aromatic compounds were the main components in the bark extracts showed by FT-IR analysis. The conventional synthesis condition used for RF resin was certainly not suitable for the RTF copolymer resin. It should be formed the novolak RF prepolymer by reacting the resorcinol with formaldehyde at the first stage, and then the bark extracts added and underwent the copolymerization reaction under acidic condition at the second-stage. The RTF copolymer resins prepared had cold-setting capability. They had higher viscosity, shorter gel time as compared with the RF resin. The RTF copolymer resins could be carried out the gluing application immediately after the hardener was added and had bonding strength the same as RF resin. But the RTF copolymer resins had worse stability and shorter shelf life than RF resin.

  16. Effect of Dam operation on monthly and annual trends of flow discharge in the Qom Rood Watershed, Iran

    Science.gov (United States)

    Yaghmaei, Hiva; Sadeghi, Seyed Hamidreza; Moradi, Hamidreza; Gholamalifard, Mehdi

    2018-02-01

    Trends in flow discharge, temperature and rainfall from the Qom Rood Watershed, Iran, for a period of 1979-2016 were analyzed at monthly and annual time scales. Trend analyses were conducted using the Mann-Kendall test, the double-mass curve of mean annual discharge versus rainfall, and rainfall-runoff relationship before and after the 15 Khordad Dam operation. Multiple regression of flow discharge against rainfall and temperature was used to determine the residual trend at four meteorological and hydrological stations located upstream and downstream of the Qom Rood Watershed. Results showed that the temperature at the upstream and downstream stations did not have any significant trend, but a significant decreasing trend (P Dam operation. Annual mean discharge at the upstream stations did not show a significant change before and after 15 Khordad Dam operation. However, annual flow magnitude decreased significantly by 87.5 and 81.7% in Shad Abad and KoohSefid, respectively. These results confirmed that natural driving forces did not affect flow discharge changes and the observed decreasing tendency in flow discharge at the downstream stations was due to 15 Khordad Dam, and at the upstream stations due to diversion/storage dams. These findings highlighted the role of human interference in changing the hydrologic regime in the study area based on which appropriate adaptive decisions can be made.

  17. Hydropower generation, flood control and dam cascades: A national assessment for Vietnam

    Science.gov (United States)

    Nguyen-Tien, Viet; Elliott, Robert J. R.; Strobl, Eric A.

    2018-05-01

    Vietnam is a country with diverse terrain and climatic conditions and a dependency on hydropower for a significant proportion of its power needs and as such, is particularly vulnerable to changes in climate. In this paper we apply SWAT (Soil and Water Assessment Tool) derived discharge simulation results coupled with regression analysis to estimate the performance of hydropower plants for Vietnam between 1995 and mid-2014 when both power supply and demand increased rapidly. Our approach is to examine the watershed formed from three large inter-boundary basins: The Red River, the Vietnam Coast and the Lower Mekong River, which have a total area of 977,964 km2. We then divide this area into 7,887 sub-basins with an average area of 131.6 km2 (based on level 12 of HydroSHEDS/HydroBASINS datasets) and 53,024 Hydrological Response Units (HRUs). Next we simulate river flow for the 40 largest hydropower plants across Vietnam. Our validation process demonstrates that the simulated flows are significantly correlated with the gauged inflows into these dams and are able to serve as a good proxy for the inflows into hydropower dams in our baseline energy regression, which captures 87.7% of the variation in monthly power generation. In other results we estimate that large dams sacrifice on average around 18.2% of their contemporaneous production for the purpose of flood control. When we assess Vietnam's current alignment of dams we find that the current cascades of large hydropower dams appear to be reasonably efficient: each MWh/day increase in upstream generation adds 0.146 MWh/day to downstream generation. The study provides evidence for the multiple benefits of a national system of large hydropower dams using a cascade design. Such a system may help overcome future adverse impacts from changes in climate conditions. However, our results show that there is still room for improvement in the harmonization of cascades in some basins. Finally, possible adverse hydro

  18. The effects of fire-breaks on plant diversity and species composition ...

    African Journals Online (AJOL)

    There is a dearth of knowledge on the effects of annual burning of fire-breaks on species composition, plant diversity and soil properties. Whittaker's plant diversity technique was used to gather data on species composition and diversity in four grassland communities on the Loskop Dam Nature Reserve (LDNR). The study ...

  19. Perdas de solo e água em plantio de Acacia mangium wild e savana em Roraima, norte da Amazônia Soil and water losses in Acacia mangium wild plantations and natural savanna in Roraima, northern Amazon

    Directory of Open Access Journals (Sweden)

    Luciana da Silva Barros

    2009-04-01

    Full Text Available Plantios florestais de Acacia mangium constituem uma alternativa cada vez mais adotada em áreas de savanas do norte da Amazônia (Roraima e podem causar alterações significativas de características do solo. Neste sentido, o objetivo deste estudo foi determinar perdas de solo e de água por erosão, que ocorrem em escoamento superficial (run off em savana nativa e plantios de acácia na região Amazônica. Para isso, foram instaladas em duas fazendas, Santa Rita e Araçá, localizadas no município de Bonfim, na região da Serra da Lua, calhas coletoras de sedimentos, acopladas a caixas d'água, em Argissolo Vermelho-Amarelo. Foram determinadas a granulometria, a densidade aparente (Dap, a resistência à penetração (RP e a velocidade de infiltração (VIB, bem como parâmetros físicos relacionados a perdas de solo. O delineamento experimental utilizado foi o de blocos ao acaso, com três tratamentos: cobertura natural de savana (SV, plantio de Acacia mangium com um ano de idade (P1 e plantio de Acacia mangium com quatro anos de idade (P4, em três repetições. O experimento teve a duração de 12 meses (setembro de 2006 a agosto de 2007. Os resultados indicaram maiores perdas de solo e de água no plantio mais recente de acácia (P1, de savana nativa e do plantio com 4 anos (P4. Os resultados foram atribuídos à exposição do solo no período inicial de desenvolvimento da planta, ao selamento superficial e à coesão do solo. O pico de perdas de solo ocorreu nos meses de abril a agosto, sendo o tipo de cobertura vegetal o fator determinante para redução das perdas de solo e de água por erosão, sendo que as práticas de plantio no sentido do declive provavelmente agravaram as perdas de solo nos plantios de Acácia. Neste trabalho, a densidade do solo e o teor de matéria orgânica não representaram bons indicadores do tipo de manejo adotado na área.As an alternative land use of savanna areas in Roraima, commercial forest stands of

  20. Effects of chopping, and soaking in water, hydrochloric acidic and calcium hydroxide solutions on the nutritional value of Acacia villosa for goats

    International Nuclear Information System (INIS)

    Wina, E.; Tangendjaja, B.; Susana, I.W.R.

    2005-01-01

    Acacia villosa, a thornless shrub legume, has potential as a feed supplement for ruminants if anti-nutritional factors, especially tannins, can be overcome. The effects of chopping and soaking the leaves on the amounts of tannin in the extracting solution and that left in the recovered leaves were studied. The tannin and non-tannin phenolics were solubilized in the extracting solution and the amount was increased with the soaking time. Soaking in calcium hydroxide solution, hydrochloric acid or water removed 41-76% of tannin and total phenolics removed from the recovered leaves. Soaking of the leaves also removed fermentable materials and reduced the gas production. In the first of two digestibility experiments, three groups of goats received one of these diets, those were: (1) sugar cane tops: unsoaked Acacia leaves (7:3), (2) sugar cane tops: water soaked Acacia leaves (7:3) and (3) sugar cane tops: water soaked Acacia leaves (7:3) + 100 g/day of cassava flour. Live weight of goats was measured every 2 weeks and a large increase in average daily gain was obtained for goats fed diet containing water soaked leaves and cassava flour (71 g/day) compared to those fed diet containing unsoaked leaves and water soaked leaves (38.9 and 44.7 g/day, respectively) (P 0.05) found in intake or digestibility between unsoaked and soaked leaves. In conclusion, soaking reduced tannin in Acacia leaves, improved digestibility and intake of Acacia leaves. In the presence of cassava flour, soaking improved average daily gain. Diets supplemented with water soaked Acacia leaves probably also need an energy supplement and cassava flour is one of the feed ingredients that is satisfactory. (author)

  1. DAM BREACH PARAMETERS AND THEIR INFLUENCE ON FLOOD HYDROGRAPHS FOR MOSUL DAM

    Directory of Open Access Journals (Sweden)

    TALAL A. BASHEER

    2017-11-01

    Full Text Available Dams breach geometry prediction is crucial in dam break studies. The characteristics of flood hydrographs resulting from a dam breach essentially depend on the breach geometry and the required time for breach formation. To investigate the impact of breach parameters on maximum breaching outflows, five breach prediction approaches were implemented to calculate the flood hydrographs using HEC-RAS model, for Mosul dam. Numerous reservoir water levels for each approach were considered. ensitivity analysis was carried out to evaluate the effect of each parameter on the resulting flood hydrographs. The time and value of peak discharge for each scenario were analysed and discussed. Results show that the most suitable method for estimating breach parameters for Mosul dam was the Froehlich approach. Furthermore, the sensitivity analysis shows that the breach side slope does not affect the peak discharge time and has a minor influence on peak outflow values. Meanwhile, the required time for the breach to develop was highly sensitive to both peak discharge and peak discharge time.

  2. Dam Seepage Investigation of an Earthfill Dam in Warren County, Missouri Using Geophysical Methods

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    Stanley C. Nwokebuihe

    2017-01-01

    Full Text Available Electrical resistivity tomography (ERT, induced polarization (IP and spontaneous potential (SP data were acquired across and in proximity to a leaking earth-fill dam (Wolf Creek dam in Warren County, Missouri. The objectives were to identify and map probable seepage pathways through the dam and to determine if the outlet works drainage pipe used in the construction of the dam was leaking. On the basis of the integrated interpretation of the acquired geophysical data two probable seepage pathways through the leaking earth-fill dam were identified and mapped. These two pathways are referred to as the Groin Leak and Water Fall Leak, respectively. The Groin Leak and Water Fall Leak seepage pathways are both characterized by relatively low resistivity and low chargeability. It is also concluded that there is high probability that water is leaking from the downstream end of the outlet works drainage pipe. The interpreted drainage pipe leak (Outlet works Leak is characterized by relatively low resistivity, high chargeability and negative self-potential values.

  3. Sediment Transport Over Run-of-River Dams

    Science.gov (United States)

    O'Brien, M.; Magilligan, F. J.; Renshaw, C. E.

    2016-12-01

    Dams have numerous documented effects that can degrade river habitat downstream. One significant effect of large dams is their ability to trap sediment delivered from upstream. This trapping can alter sediment transport and grain size downstream - effects that often motivate dam removal decisions. However, recent indirect observations and modeling studies indicate that small, run-of-river (ROR) dams, which do not impede discharge, may actually leak sediment downstream. However, there are no direct measurements of sediment flux over ROR dams. This study investigates flow and sediment transport over four to six different New England ROR dams over a summer-fall field season. Sediment flux was measured using turbidity meters and tracer (RFID) cobbles. Sediment transport was also monitored through an undammed control site and through a river where two ROR dams were recently removed. These data were used to predict the conditions that contribute to sediment transport and trapping. Year 1 data show that tracer rocks of up to 61 mm were transported over a 3 m ROR dam in peak flows of 84% of bankfull stage. These tracer rocks were transported over and 10 m beyond the dam and continue to move downstream. During the same event, comparable suspended sediment fluxes of up to 81 g/s were recorded both upstream and downstream of the dam at near-synchronous timestamps. These results demonstrate the potential for sediment transport through dammed rivers, even in discharge events that do not exceed bankfull. This research elucidates the effects of ROR dams and the controls on sediment transport and trapping, contributions that may aid in dam management decisions.

  4. Dam spills and fishes; Eclusees et poissons

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This short paper reports the main topics discussed during the two days of the annual colloquium of the Hydro-ecology Committee of EdF. The first day was devoted to the presentation of the joint works carried out by EdF, the Paul-Sabatier University (Toulouse), the Provence St-Charles University (Marseille), the ENSAT (Toulouse) and the CEMAGREF (Lyon and Aix-en-Provence) about the environmental impact of dam spills on the aquatic flora and fauna downstream. A synthesis and recommendations were presented for the selection and characterization of future sites. The second day was devoted to the hydro-ecology study of the dam reservoir of Petit-Saut (French Guyana): water reoxygenation, quality evolution, organic matter, plankton, invertebrates and fishes. The 134 French dams concerned by water spills have been classified according to the frequency of spills, the variations of flow rates created, and their impacts on fishing, walking, irrigation, industry, drinking water, navigation, bathing. Particular studies on different sites have demonstrated the complexity of the phenomena involved concerning the impact on the ecosystems and the water quality. (J.S.).

  5. Three Sisters Dam: Investigations and monitoring

    International Nuclear Information System (INIS)

    Slopek, R.J.; Courage, L.J.R.; Keys, R.A.

    1990-01-01

    The geotechnical investigations, monitoring and interpretation of data associated with the evaluation of the Three Sisters Dam, which has been suffering from excessive seepage and is in need of enhancement, are outlined. The Three Sisters Dam is located in the continental ranges of the Rocky Mountains in Alberta, impounding the Spray Reservoir, and is founded on 60 m of interbedded sand, gravel, silt and clay layers. The computer code PC-SEEP was used to evaluate seepage. Details are provided of drilling, ground-penetrating radar surveys, seismic surveys, penstock inspection, sinkhole activity, piezometer monitoring, silt wells, settlement monuments, and tailrace monitoring. The intensive investigations of the foundations showed that they consist of a complex formation of interfingered stratified layers and leases of talus and glaciofluvial deposits. Due to the depth and nature of these materials drill hole penetration was limited to the use of the Becker hammer. This equipment successfully delineated the major soil horizons of the foundation. The continued information attained from inspection, drilling, testing, radar surveys, seismic work, monitoring of piezometers, leakage, silt wells and settlement monuments indicated that there are no large voids within the foundation of the dam. 2 refs., 12 figs

  6. How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation.

    Science.gov (United States)

    Fencl, Jane S; Mather, Martha E; Costigan, Katie H; Daniels, Melinda D

    2015-01-01

    Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0-15.3 km) or 287 wetted widths (136-437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach that has been applied to larger dams.

  7. Biosynthesis of silver nanoparticles using Acacia leucophloea extract and their antibacterial activity

    Directory of Open Access Journals (Sweden)

    Murugan K

    2014-05-01

    Full Text Available Kasi Murugan,1 Balakrishnan Senthilkumar,2,3 Duraisamy Senbagam,2 Saleh Al-Sohaibani11Department of Microbiology and Botany, College of Science, King Saud University, Riyadh, Saudi Arabia; 2Department of Biotechnology, Muthayammal College of Arts and Science, Rasipuram, Tamil Nadu, India; 3Department of Medical Microbiology, School of Medicine, Health and Medical Science College, Haramaya University, Harar, EthiopiaAbstract: The immense potential of nanobiotechnology makes it an intensely researched field in modern medicine. Green nanomaterial synthesis techniques for medicinal applications are desired because of their biocompatibility and lack of toxic byproducts. We report the toxic byproducts free phytosynthesis of stable silver nanoparticles (AgNPs using the bark extract of the traditional medicinal plant Acacia leucophloea (Fabaceae. Visual observation, ultraviolet–visible spectroscopy, and transmission electron microscopy (TEM were used to characterize the synthesized AgNPs. The visible yellow-brown color formation and surface plasmon resonance at 440 nm indicates the biosynthesis of AgNP. The TEM images show polydisperse, mostly spherical AgNP particles of 17–29 nm. Fourier transform infrared spectroscopy revealed that primary amines, aldehyde/ketone, aromatic, azo, and nitro compounds of the A. leucophloea extract may participate in the bioreduction and capping of the formed AgNPs. X-ray diffraction confirmed the crystallinity of the AgNPs. The in vitro agar well diffusion method confirmed the potential antibacterial activity of the plant extract and synthesized AgNPs against the common bacterial pathogens Staphylococcus aureus (MTCC 737, Bacillus cereus (MTCC 1272, Listeria monocytogenes (MTCC 657, and Shigella flexneri (MTCC 1475. This research combines the inherent antimicrobial activity of silver metals with the A. leucophloea extract, yielding antibacterial activity-enhanced AgNPs. This new biomimetic approach using

  8. Carbon dioxide emissions from an Acacia plantation on peatland in Sumatra, Indonesia

    Directory of Open Access Journals (Sweden)

    A. Hooijer

    2012-02-01

    Full Text Available Peat surface CO2 emission, groundwater table depth and peat temperature were monitored for two years along transects in an Acacia plantation on thick tropical peat (>4 m in Sumatra, Indonesia. A total of 2300 emission measurements were taken at 144 locations, over a 2 year period. The autotrophic root respiration component of CO2 emission was separated from heterotrophic emission caused by peat oxidation in three ways: (i by comparing CO2 emissions within and beyond the tree rooting zone, (ii by comparing CO2 emissions with and without peat trenching (i.e. cutting any roots remaining in the peat beyond the tree rooting zone, and (iii by comparing CO2 emissions before and after Acacia tree harvesting. On average, the contribution of autotrophic respiration to daytime CO2 emission was 21% along transects in mature tree stands. At locations 0.5 m from trees this was up to 80% of the total emissions, but it was negligible at locations more than 1.3 m away. This means that CO2 emission measurements well away from trees were free of any autotrophic respiration contribution and thus represent only heterotrophic emissions. We found daytime mean annual CO2 emission from peat oxidation alone of 94 t ha−1 y−1 at a mean water table depth of 0.8 m, and a minimum emission value of 80 t ha−1 y−1 after correction for the effect of diurnal temperature fluctuations, which may result in a 14.5% reduction of the daytime emission. There is a positive correlation between mean long-term water table depth and peat oxidation CO2 emission. However, no such relation is found for instantaneous emission/water table depth within transects and it is clear that factors other than water table depth also affect peat oxidation and total CO2 emissions. The increase in the temperature of the surface peat due to plantation establishment may explain over 50% of peat oxidation emissions. Our study sets a standard for greenhouse gas flux studies from tropical peatlands under

  9. Do Hydroelectric Dams Mitigate Global Warming? The Case of Brazil's Curuna Dam

    Energy Technology Data Exchange (ETDEWEB)

    Fearnside, P.M. [National Institute for Research in the Amazon (INPA), C.P. 478, 69011-970 Manaus, Amazonas (Brazil)

    2005-10-15

    Hydroelectric dams in tropical forest areas emit greenhouse gases, as illustrated by the Curuna dam in the Amazonian portion of Brazil. Emissions include carbon dioxide from decay of the above-water portions of trees that are left standing in the reservoir and methane from soft vegetation that decays under anaerobic conditions on the bottom of the reservoir, especially macrophytes (water weeds) and vegetation that grows in the drawdown zone and is flooded when the reservoir water level rises. Some methane is released from the reservoir surface through bubbling and diffusion, but larger amounts are released from water passing through the turbines and spillway. Methane concentration in the water increases with depth, and the turbines and spillway draw water from sufficient depth to have substantial methane content. In 1990 (13 years after filling), the Curuna Dam emitted 3.6 times more greenhouse gases than would have been emitted by generating the same amount of electricity from oil.

  10. Simulating dam-breach flood scenarios of the Tangjiashan landslide dam induced by the Wenchuan Earthquake

    Directory of Open Access Journals (Sweden)

    X. Fan

    2012-10-01

    Full Text Available Floods from failures of landslide dams can pose a hazard to people and property downstream, which have to be rapidly assessed and mitigated in order to reduce the potential risk. The Tangjiashan landslide dam induced by the Mw = 7.9 2008 Wenchuan earthquake had impounded the largest lake in the earthquake affected area with an estimated volume of 3 × 108 m3, and the potential catastrophic dam breach posed a serious threat to more than 2.5 million people in downstream towns and Mianyang city, located 85 km downstream. Chinese authorities had to evacuate parts of the city until the Tangjiashan landslide dam was artificially breached by a spillway, and the lake was drained. We propose an integrated approach to simulate the dam-breach floods for a number of possible scenarios, to evaluate the severity of the threat to Mianyang city. Firstly, the physically-based BREACH model was applied to predict the flood hydrographs at the dam location, which were calibrated with observational data of the flood resulting from the artificial breaching. The output hydrographs from this model were inputted into the 1-D–2-D SOBEK hydrodynamic model to simulate the spatial variations in flood parameters. The simulated flood hydrograph, peak discharge and peak arrival time at the downstream towns fit the observations. Thus this approach is capable of providing reliable predictions for the decision makers to determine the mitigation plans. The sensitivity analysis of the BREACH model input parameters reveals that the average grain size, the unit weight and porosity of the dam materials are the most sensitive parameters. The variability of the dam material properties causes a large uncertainty in the estimation of the peak flood discharge and peak arrival time, but has little influence on the flood inundation area and flood depth downstream. The effect of cascading breaches of smaller dams downstream of the Tangjiashan dam was

  11. Worldwide review of existing standards and procedures for monitoring and analysing dam deformations

    International Nuclear Information System (INIS)

    Chrzanowski, A.; Avella, S.; Frodge, S.L.

    1993-01-01

    A study was carried out of existing standards and procedures for dam monitoring worldwide. The survey covers worldwide distribution of large dams, dam failures and dam safety legislation, required accuracy and frequency of monitoring surveys, and geometrical analysis of dam deformations. Information is tabulated, on a per-country basis, of number of dam types, actual or preferred method of monitoring, dam safety legislation in place, standards and specifications for monitoring, whether automation of monitoring is included, whether geodetic systems have been designed, and sample specifications for monitoring concrete dams as recommended by the Swiss National Committee on Large Dams. 29 refs., 3 tabs

  12. Dams and Rivers: A Primer on the Downstream Effects of Dams

    Science.gov (United States)

    Collier, Michael; Webb, Robert H.; Schmidt, John C.

    1996-01-01

    The U.S. Geological Survey is charged with monitoring the water and mineral resources of the United States. Beginning in 1889, the Survey established a network of water gaging stations across most of the country's rivers; some also measured sediment content of the water. Consequently, we now have valuable long-term data with which to track water supply, sediment transport, and the occurrence of floods. Many variables affect the flow of water from mountain brook to river delta. Some are short-term perturbations like summer thunderstorms. Others occur over a longer period of time, like the El Ninos that might be separated by a decade or more. We think of these variables as natural occurrences, but humans have exerted some of the most important changes -- water withdrawals for agriculture, inter-basin transfers, and especially the construction of an extensive system of dams. Dams have altered the flow of many of the Nation's rivers to meet societal needs. We expect floods to be contained. Irrigation is possible where deserts once existed. And water is released downstream not according to natural cycles but as dictated by a region's hour-by-hour needs for water or electricity. As a result, river channels below dams have changed dramatically. Depending on annual flow, flood peaks, and a river's sediment load, we might see changes such as sand building up in one channel, vegetation crowding into another, and extensive bank erosion in another. This Circular explores the emerging scientific arena of change in rivers below dams. This science tries first to understand and then anticipate changes to river beds and banks, and to riparian habitats and animal communities. To some degree, these downstream changes can be influenced by specific strategies of dam management. Scientists and resource managers have a duty to assemble this information and present it without bias to the rest of society. Society can then more intelligently choose a balance between the benefits and adverse

  13. Resolving the 'time lag' debate in dam stability analysis

    International Nuclear Information System (INIS)

    Grenoble, B.A.; Harris, C.W.; Morris, D.I.

    1993-01-01

    The significance of delays in uplift pressure increases during floods is a subject of ongoing debate among dam owners and regulators. Current regulatory standards do not recognize these delays, known as time lag. One recent study concludes that the regulatory approach, indeed, is reasonable. In the complete study, Stone ampersand Webster researchers evaluated uplift pressures from 17 large concrete gravity dams. Data from eight of the dams were used to study time lag. Uplift was measured as frequently as every 15 minutes at one dam, two times per day at another dam during a flood, and three times per week at six other dams. The study showed that, although there is always a small time lag, the duration of the time lag is generally not sufficient to justify reducing the uplift pressures used in stability calculations

  14. Nitrogen metabolism of sheep and goats consuming Acacia brevispica and Sesbania sesban

    Science.gov (United States)

    Woodward, A.; Reed, J.D.

    1997-01-01

    We described the effects of two East African browses, Acacia brevispica and Sesbania sesban, on nitrogen metabolism of sheep and goats. The A. brevispica had a substantial amount of proanthocyanidins (condensed tannins); S. sesban did not. The browses were fed at three levels in combination with vetch (Vicia dasycarpa) and teff straw (Eragrostis abyssinica). Fecal N, N balance, and plasma urea N (PUN) were estimated with intact animals. Ruminal ammonia (RuA) and VFA concentrations were estimated with ruminally fistulated animals. Urinary N loss, PUN, RuA, and VFA concentrations were higher for S. sesban diets than for A. brevispica diets. Fecal N was highest with diets including A. brevispica due to high levels of fecal neutral-detergent insoluble N. Nitrogen retention was highest for diets including S. sesban. Nitrogen retention was adequate for A. brevispica diets because low urinary N compensated for high fecal N. Four hypotheses describe possible effects of tannins on N metabolism: 1) escape of protein from the rumen to the lower tract; 2) increased microbial yield; 3) increase in N-containing endogenous products; and 4) protein made indigestible in tannin-protein complexes. The effect of tannins in A. brevispica on N metabolism can best be described by the formation of indigestible tannin-protein complexes, although increased production of endogenous products is also possible.

  15. Antiviral activity of Acacia nilotica against Hepatitis C Virus in liver infected cells

    Directory of Open Access Journals (Sweden)

    Javed Tariq

    2011-05-01

    Full Text Available Abstract Hepatitis C virus (HCV belonging to the family Flaviviridae has infected 3% of the population worldwide and 6% of the population in Pakistan. The only recommended standard treatment is pegylated INF-α plus ribavirin. Due to less compatibility of the standard treatment, thirteen medicinal plants were collected from different areas of Pakistan on the basis of undocumented antiviral reports against different viral infections. Medicinal plants were air dried, extracted and screened out against HCV by infecting HCV inoculums of 3a genotype in liver cells. RT-PCR results demonstrate that acetonic and methanolic extract of Acacia nilotica (AN showed more than 50% reduction at non toxic concentration. From the above results, it can be concluded that by selecting different molecular targets, specific structure-activity relationship can be achieved by doing mechanistic analysis. So, additional studies are required for the isolation and recognition of antiviral compound in AN to establish its importance as antiviral drug against HCV. For further research, we will scrutinize the synergistic effect of active antiviral compound in combination with standard PEG INF-α and ribavirin which may be helpful in exploring further gateways for antiviral therapy against HCV.

  16. Ultrasound-assisted extraction of phenolic antioxidants from Acacia confusa flowers and buds.

    Science.gov (United States)

    Tung, Yu Tang; Chang, Wei Chun; Chen, Ping Sheng; Chang, Tzu Cheng; Chang, Shang Tzen

    2011-04-01

    Acacia confusa Merr. (Leguminosae), a species native to Taiwan, is widely distributed on the hills and lowlands of Taiwan, and has been used in traditional medicines. In this study, the application of ultrasound-assisted extraction was used to extract the phenolic compounds from A. confusa flowers and buds for the first time. Among the extraction methods, it can significantly enhance the contents of phenolic compounds and antioxidant activities in A. confusa flower and bud extracts using ultrasound-assisted extraction (10  min×12 times). Considering both the solvent consumption and the time needed for extraction, ultrasound-assisted extraction was found to be the most practical approach for the rapid and efficient extraction of bioactive phenolic constituents. In addition, gallic acid, myricitrin-3-rhamnoside, quercitrin-3-rhamnoside, europetin-3-rhamnoside, kaempferol-3-rhamnoside, rhamnetin-3-glucoside, and rhamnetin-3-rhamnoside were also quantified in different extracts by RP-HPLC. It is clear that ultrasound-assisted extraction is an efficient method for extracting phenolic compounds from A. confusa flowers and buds. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Entomofauna Associada a Galhos de Acacia mangium Willd. Roletados por Oncideres saga (Dalman (Coleoptera: Cerambycidae

    Directory of Open Access Journals (Sweden)

    Gláucia Cordeiro

    2010-04-01

    Abstract. The study of the insects associated with branches and stems girdled by Oncideres saga (Dalman is important to know its possible natural enemies. Therefore, these work had the objective of register the insects associated with branches and stems girdled of Acacia mangium Willd. by this twig girdler beetle, in Coimbra, state of Minas Gerais, Brazil. Stems and branches of A. mangium were collected in January/2007 to April/2007. This material has been inspected, stored in plastic bags, and kept in a room with controlled conditions (25.4 ± 0.3°C and 66.7 ± 1.4%. It was noted the presence of a non-determined species of Scolytidae and the emergence of four species of Cerambycidae: Engyum quadrinotatum Thomsom; Eburodacrys sexmaculata (Olivier; Achryson surinamum (Linnaeus and Neoclytus pusillus (Laporte & Gory. It can be concluded that studies are needed with the objective of verify the behavior of these insects in relation with twig girdler O. saga.

  18. DETECTION OF POLLEN FLOW IN THE SEEDLING SEED ORCHARD OF Acacia mangium USING DNA MARKER

    Directory of Open Access Journals (Sweden)

    Vivi Yuskianti

    2013-06-01

    Full Text Available Pollen pattern dispersal in seedling seed orchard (SSO is an essential part of a tree-improvement program. Two SSOs of Acacia mangium in South Kalimantan and South Sumatra that represent similar resources in different environments were used in this study.  Genotypes of all trees and seeds from a subset of 10 mother trees in each orchard were determined for 12 microsatellite loci, and parentage analysis was carried out. The results shows that the pollen dispersal pattern in both SSOs decrease with distance from mother tree. Patterns of pollen dispersal, dispersal distance and cumulative frequency of pollen dispersal distance were similar in both SSOs. Random pollen dispersal were found in both SSOs. About 80% of all crosses were found within a 40-m distance range with the most frequent pollination distance between mother tree and male male parents was 0-10 m. No self-pollinated seed was detected. Application of all these aspects found in this study such as random pollen dispersal and the effective pollen dispersal distance can be useful for establishing seedling seed orchard, clonal seed orchard and in other tree improvement activities of A. mangium.

  19. Estimation of Acacia melanoxylon unbleached Kraft pulp brightness by NIR spectroscopy

    Directory of Open Access Journals (Sweden)

    António J. A. Santos

    2015-08-01

    Full Text Available Aim of the study: The ability of NIR spectroscopy for predicting the ISO brightness was studied on unbleached Kraft pulps of Acacia melanoxylon R. Br. Area of study: Sites covering littoral north, mid interior north and centre interior of Portugal. Materials and methods: The samples were Kraft pulped in standard identical conditions targeted to a kappa number of 15. A Near Infrared (NIR partial least squares regression (PLSR model was developed for the ISO brightness prediction using 75 pulp samples with a variation range of 18.9 to 47.9 %. Main results: Very good correlations between NIR spectra and ISO brightness were obtained. Ten methods were used for PLS analysis (cross validation with 48 samples, and a test set validation was made with 27 samples. The 1stDer pre-processed spectra coupling two wavenumber ranges from 9404 to 7498 cm-1 and 4605 to 4243 cm-1 allowed the best model with a root mean square error of ISO brightness prediction of 0.5 % (RMSEP, a r2 of 99.5 % with a RPD of 14.7. Research highlights: According to AACC Method 39-00, the present model is sufficiently accurate to be used for process control (RPD ≥ 8

  20. Stable isotope ratios and reforestation potential in Acacia koa populations on Hawai’i

    Directory of Open Access Journals (Sweden)

    Shaneka Lawson

    2017-12-01

    Full Text Available Stable carbon and nitrogen isotopes can be influenced by a multitude of factors including elevation, precipitation rate, season, and temperature. This work examined the variability in foliar stable carbon (δ13C and nitrogen (δ15N isotope ratios of koa (Acacia koa for 17 sites on Hawai’i Island delineated by elevation and precipitation gradients. Sites were identified and grouped with respect to mean annual precipitation (MAP, mean annual temperature (MAT and position along three elevation ranges. Analysis of the resultant δ13C and δ15N isotope ratios from multiple individuals at these sites indicated that certain sites showed a demonstrated correlation between carbon and/or nitrogen content, isotope ratios, precipitation, and elevation however many sites showed no correlation. We used publicly available temperature and moisture data to help eliminate confounding effects by climatic drivers and capture possible points of contention. At sites where the temperature, precipitation, and elevation data were not significantly different we compared stable isotope information to determine if additional variables could have contributed to the lack of more correlative data. Our results note several areas within the Waiakea Forest Reserve and Volcanoes National Park where, based on isotope results, reforestation efforts could be most successfully initiated.