Dissecting variation in biomass conversion factors across China's forests: implications for biomass and carbon accounting.

Science.gov (United States)

Luo, Yunjian; Zhang, Xiaoquan; Wang, Xiaoke; Ren, Yin

2014-01-01

Biomass conversion factors (BCFs, defined as the ratios of tree components (i.e. stem, branch, foliage and root), as well as aboveground and whole biomass of trees to growing stock volume, Mg m-3) are considered as important parameters in large-scale forest biomass carbon estimation. To date, knowledge of possible sources of the variation in BCFs is still limited at large scales. Using our compiled forest biomass dataset of China, we presented forest type-specific values of BCFs, and examined the variation in BCFs in relation to forest type, stand development and environmental factors (climate and soil fertility). BCFs exhibited remarkable variation across forest types, and also were significantly related to stand development (especially growing stock volume). BCFs (except Stem BCF) had significant relationships with mean annual temperature (MAT) and mean annual precipitation (MAP) (Pforest carbon estimates, we should apply values of BCFs for a specified forest type, and also consider climatic and edaphic effects, especially climatic effect, in developing predictive models of BCFs (except Stem BCF).

Abiotic factors affect the recruitment and biomass of perennial grass and evergreen shrub seedlings in denuded areas of Patagonian Monte rangelands.

Science.gov (United States)

Bosco, Tomás; Bertiller, Mónica Beatriz; Carrera, Analía Lorena

2018-07-15

Assessing the ability of key species to cope with environmental stresses in disturbed areas is an important issue for recovery of degraded arid ecosystem. Our objective was to evaluate the effect of soil moisture, exposure to UV radiation, and presence/absence of litter with different chemistry on soil N, recruitment and biomass of seedlings of perennial grass (Poa ligularis and Nassella tenuis) and evergreen shrub species (Atriplex lampa and Larrea divaricata) in denuded areas. We carried out a microcosm experiment with soil blocks (28 cm depth) sowed with seeds of the target species, subjected to different levels of litter type (perennial grass-evergreen shrub mixture, evergreen shrub mixture, and no litter), UV radiation (near ambient and reduced UV), and soil water (high: 15-25% and low 5-15%). Periodically, during 6 months, we assessed soil-N (total and inorganic) at two depths and species seedling recruitment at microcosms. Additionally, emerged seedlings of each species were transplanted to individual pots containing soil and subjected to the same previous factors during 12 months. Then, all plants were harvested and biomass assessed. Only inorganic soil-N at the upper soil varied among treatments increasing with the presence of evergreen shrub litter, exposure to ambient UV, and high soil water. Inorganic soil-N, promoted by near ambient UV and high soil water, had a positive effect on recruitment of perennial grasses and A. lampa. Both litter types promoted the recruitment of perennial grasses. Evergreen shrub litter and high soil water promoted the recruitment of L. divaricata. Seedling biomass of perennial grasses increased with high soil water and reduced UV. Ambient UV had positive or null effects on biomass of evergreen shrub seedlings. High soil water increased biomass of L. divaricata seedlings. We concluded that soil water appeared as the most limiting factor for seedling recruitment of all species whereas inorganic soil N limited the

Root biomass in cereals, catch crops and weeds can be reliably estimated without considering aboveground biomass

DEFF Research Database (Denmark)

Hu, Teng; Sørensen, Peter; Wahlström, Ellen Margrethe

2018-01-01

and management factors may affect this allometric relationship making such estimates uncertain and biased. Therefore, we aimed to explore how root biomass for typical cereal crops, catch crops and weeds could most reliably be estimated. Published and unpublished data on aboveground and root biomass (corrected...

Anthropogenic disturbances affect population size and biomass allocation of two alpine species from the headwater area of the Urumqi River, China

International Nuclear Information System (INIS)

Zhao, R.; Zhang, H.; An, L.

2018-01-01

The survival of alpine plants are seriously threatened by increasing anthropogenic activity. Saussurea involucrata and Rhodiola quadrifida are particularly affected because of their high medicinal value. To assess the impact of anthropogenic disturbance on the two species, their population size and biomass allocation were examined at three levels of disturbance at low and high altitudes. Anthropogenic disturbance was the most serious threat to the populations and changed the population density, biomass, and biomass allocation of both species significantly (p<0.05). The changes differed with the species and the altitude, and were also affected by the interaction between these two factors. Population density and biomass of the two species decreased with an increase in the level of anthropogenic disturbance. These results imply that the decrease in population size and in biomass allocation to reproductive organs due to anthropogenic disturbances may make the plant populations even smaller and scarce. Meanwhile, change of making their survival dependent on the extent of anthropogenic disturbance: unless such disturbance is checked and the species are protected, they will probably disappear from the headwater area of the Urumqi River. This influence of anthropogenic disturbances may be potential threats to population ability of survival and reproduction. (author)

Allometric biomass and carbon factors database

Energy Technology Data Exchange (ETDEWEB)

Somogyi, Z. [European Commission Joint Research Centre, Ispra (Italy). Institute for Environment and Sustainability]|[Hungarian Forest Research Institute, Budapest (Hungary); Teobaldelli, M.; Federici, S.; Pagliari, V.; Grassi, G.; Seufert, G. [European Commission Joint Research Centre, Ispra (Italy). Institute for Environment and Sustainability; Matteucci, G. [Consiglio Nazionale delle Ricerche, Rende (Italy). Istituto per i Sistemi Agricoli e Forestali del Mediterraneo

2008-09-30

DATA clearinghouse. The 'Allometric, Biomass and Carbon factors' database (ABC factors database) was designed to facilitate the estimation of the biomass carbon stocks of forests in order to support the development and the verification of greenhouse gas inventories in the LULUCF sector. The database contains several types of expansion, conversion and combined factors, by various tree species or species groups that can be used to calculate biomass or carbon of forests of Eurasian region from proxy variables (e.g., tree volume) that may come from forest inventories. In addition to the factors, and depending on the information that was available in the cited source, the database indicates: (1) the biomass compartments involved when the factor was developed; and (2) the possible applicability of the factor, e.g. by country or by ecological regions. The applicability of the factors is either suggested by the source itself, or the type of source (e.g. National Greenhouse Gas Inventory Report), or was based on the expert judgement by the compilers of the database. Finally, in order to facilitate the selection of the most appropriate of the data, the web-based interface provides the possibility to compare several factors that may come from different sources.

Factors Contributing to Use of Biomass as Domestic Fuel and ...

African Journals Online (AJOL)

Biomass energy dominates household cooking energy in developing countries and Nigeria is not exceptional. However, a number of implications such as indoor air pollution, environmental degradation and social burden have been associated with the use of biomass energy. The paper discusses factors that determine the ...

Exploration of factors limiting biomass estimation by polarimetric radar in tropical forests

NARCIS (Netherlands)

Quiñones Fernández, M.J.; Hoekman, D.H.

2004-01-01

Direct inversion of radar return signals for forest biomass estimation is limited by signal saturation at medium biomass levels (roughly 150 ton/ha for P-band). Disturbing factors such as forest structural differences-and, notably, at low biomass levels, terrain roughness, and soil moisture

Biomass burning in Africa: As assessment of annually burned biomass

International Nuclear Information System (INIS)

Delmas, R.A.; Loudjani, P.; Podaire, A.; Menaut, J.C.

1991-01-01

It is now established that biomass burning is the dominant phenomenon that controls the atmospheric chemistry in the tropics. Africa is certainly the continent where biomass burning under various aspects and processes is the greatest. Three different types of burnings have to be considered-bush fires in savanna zones which mainly affect herbaceous flora, forest fires due to forestation for shifting agriculture or colonization of new lands, and the use of wood as fuel. The net release of carbon resulting from deforestation is assumed to be responsible for about 20% of the CO 2 increase in the atmosphere because the burning of forests corresponds to a destorage of carbon from the biospheric reservoir. The amount of reactive of greenhouse gases emitted by biomass burning is directly proportional, through individual emission factors, to the biomass actually burned. This chapter evaluates the biomass annually burned on the African continent as a result of the three main burning processes previously mentioned

Emission factors from residential combustion appliances burning Portuguese biomass fuels.

Science.gov (United States)

Fernandes, A P; Alves, C A; Gonçalves, C; Tarelho, L; Pio, C; Schimdl, C; Bauer, H

2011-11-01

Smoke from residential wood burning has been identified as a major contributor to air pollution, motivating detailed emission measurements under controlled conditions. A series of experiments were performed to compare the emission levels from two types of wood-stoves to those of fireplaces. Eight types of biomass were burned in the laboratory: wood from seven species of trees grown in the Portuguese forest (Pinus pinaster, Eucalyptus globulus, Quercus suber, Acacia longifolia, Quercus faginea, Olea europaea and Quercus ilex rotundifolia) and briquettes produced from forest biomass waste. Average emission factors were in the ranges 27.5-99.2 g CO kg(-1), 552-1660 g CO(2) kg(-1), 0.66-1.34 g NO kg(-1), and 0.82-4.94 g hydrocarbons kg(-1) of biomass burned (dry basis). Average particle emission factors varied between 1.12 and 20.06 g kg(-1) biomass burned (dry basis), with higher burn rates producing significantly less particle mass per kg wood burned than the low burn rates. Particle mass emission factors from wood-stoves were lower than those from the fireplace. The average emission factors for organic and elemental carbon were in the intervals 0.24-10.1 and 0.18-0.68 g kg(-1) biomass burned (dry basis), respectively. The elemental carbon content of particles emitted from the energy-efficient "chimney type" logwood stove was substantially higher than in the conventional cast iron stove and fireplace, whereas the opposite was observed for the organic carbon fraction. Pinus pinaster, the only softwood species among all, was the biofuel with the lowest emissions of particles, CO, NO and hydrocarbons.

Public beliefs that may affect biomass development

International Nuclear Information System (INIS)

Draper, H.M.

1993-01-01

The Tennessee River chip mill controversy involves the expansion of the pulp and paper industry rather than the biomass energy industry; however, the concerns expressed by environmentalists are likely to be the same for biomass projects that propose use of privately-owned land. It may be incorrect to assume that private landowners will have more flexibility in forest management techniques than public agencies. In fact, when faced with a potentially large new demand source for wood, environmentalists will try to stop the project while pushing for stringent regulation of harvesting. This paper describes and analyzes beliefs about forest management (related to biomass energy) taken from the 1,200 letters and 200 public hearing statements received by TVA on the chip mill environmental impact statement. The chip mill controversy suggests that there is a potential for strong coalitions to form to stop new biomass demand sources. As much as possible, the biomass industry will need to anticipate and address land management issues. New concepts such as landscape ecology and ecosystem management should be considered. Even so, increased use of non-dedicated biomass resources will require more public acceptance of the concept that ecosystems and their biomass resources can tolerate increased levels of management

Thermal characteristics of various biomass fuels in a small-scale biomass combustor

International Nuclear Information System (INIS)

Al-Shemmeri, T.T.; Yedla, R.; Wardle, D.

2015-01-01

Biomass combustion is a mature and reliable technology, which has been used for heating and cooking. In the UK, biomass currently qualifies for financial incentives such as the Renewable Heat Incentive (RHI). Therefore, it is vital to select the right type of fuel for a small-scale combustor to address different types of heat energy needs. In this paper, the authors attempt to investigate the performance of a small-scale biomass combustor for heating, and the impact of burning different biomass fuels on useful output energy from the combustor. The test results of moisture content, calorific value and combustion products of various biomass samples were presented. Results from this study are in general agreement with published data as far as the calorific values and moisture contents are concerned. Six commonly available biomass fuels were tested in a small-scale combustion system, and the factors that affect the performance of the system were analysed. In addition, the study has extended to examine the magnitude and proportion of useful heat, dissipated by convection and radiation while burning different biomass fuels in the small-scale combustor. It is concluded that some crucial factors have to be carefully considered before selecting biomass fuels for any particular heating application. - Highlights: • Six biomass materials combustion performance in a small combustor was examined. • Fuel combustion rate and amount of heat release has varied between materials. • Heat release by radiation, convection and flue gasses varied between materials. • Study helps engineers and users of biomass systems to select right materials

Biomass equations and biomass expansion factors (BEFs) for pine (pinus spp.), spruce (picea spp.) and broadleaved dominated stands in Norway

OpenAIRE

Viken, Knut Ole

2012-01-01

Abstract The objectives of this study were (1) to develop models for estimation of stand-level tree biomass for spruce (picea spp.)- pine (pinus spp.)- and broadleaved-dominated forest in Norway and, (2) develop biomass expansion factors (BEFs; ratio of stem volume to biomass) which convert stem volume to whole tree biomass for Norwegian forest conditions. A dataset from a 5 year period (2006 – 2010) from the Norwegian National Forest Inventory (NFI) were used to develop the...

Allometric relationship and biomass expansion factors (BEFs) for above- and below-ground biomass prediction and stem volume estimation for ash (Fraxinus excelsior L.) and oak (Quercus robur L.)

Czech Academy of Sciences Publication Activity Database

Krejza, Jan; Světlík, J.; Bednář, P.

2017-01-01

Roč. 31, č. 4 (2017), s. 1303-1316 ISSN 0931-1890 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : floodplain forest * root biomass * leaf biomass * branch biomass * shoot biomass * Allometry * stem volume * biomass expansion factor Subject RIV: GK - Forestry OBOR OECD: Forestry Impact factor: 1.842, year: 2016

Investigating commercial cellulase performances toward specific biomass recalcitrance factors using reference substrates.

Science.gov (United States)

Ju, Xiaohui; Bowden, Mark; Engelhard, Mark; Zhang, Xiao

2014-05-01

Three commercial cellulase preparations, Novozymes Cellic(®) Ctec2, Dupont Accellerase(®) 1500, and DSM Cytolase CL, were evaluated for their hydrolytic activity using a set of reference biomass substrates with controlled substrate characteristics. It was found that lignin remains a significant recalcitrance factor to all the preparations, although different enzyme preparations respond to the inhibitory effect of lignin differently. Also, different types of biomass lignin can inhibit cellulase enzymes in different manners. Enhancing enzyme activity toward biomass fiber swelling is an area significantly contributing to potential improvement in cellulase performance. While the degree of polymerization of cellulose in the reference substrates did not present a major recalcitrance factor to Novozymes Cellic(®) Ctec2, cellulose crystallite has been shown to have a significant lower reactivity toward all enzyme mixtures. The presence of polysaccharide monooxygenases (PMOs) in Novozymes Ctec2 appears to enhance enzyme activity toward decrystallization of cellulose. This study demonstrated that reference substrates with controlled chemical and physical characteristics of structural features can be applied as an effective and practical strategy to identify cellulosic enzyme activities toward specific biomass recalcitrance factor(s) and provide specific targets for enzyme improvement.

Factors affecting seawater-based pretreatment of lignocellulosic date palm residues

DEFF Research Database (Denmark)

Fang, Chuanji; Thomsen, Mette Hedegaard; Frankaer, Christian Grundahl

2017-01-01

Seawater-based pretreatment of lignocellulosic biomass is an innovative process at research stage. With respect to process optimization, factors affecting seawater-based pretreatment of lignocellulosic date palm residues were studied for the first time in this paper. Pretreatment temperature (180...... °C–210 °C), salinity of seawater (0 ppt–50 ppt), and catalysts (H2SO4, Na2CO3, and NaOH) were investigated. The results showed that pretreatment temperature exerted the largest influence on seawater-based pretreatment in terms of the enzymatic digestibility and fermentability of pretreated solids...

Biomass Assessment. Assessment of global biomass potentials and their links to food, water, biodiversity, energy demand and economy. Inventory and analysis of existing studies. Supporting document

International Nuclear Information System (INIS)

Dornburg, V.; Faaij, A.; Verweij, P.; Banse, M.; Van Diepen, K.; Van Keulen, H.; Langeveld, H.; Meeusen, M.; Van de Ven, G.; Wester, F.; Alkemade, R.; Ten Brink, B.; Van den Born, G.J.; Van Oorschot, M.; Ros, J.; Smout, F.; Van Vuuren, D.; Van den Wijngaart, R.; Aiking, H.; Londo, M.; Mozaffarian, H.; Smekens, K.; Lysen, E.

2008-01-01

This supporting document contains the result from the inventory phase of the biomass assessment of global biomass potentials and their links to food, water, biodiversity, energy demand and economy. This study provides a comprehensive assessment of global biomass potential estimates, focusing on the various factors affecting these potentials, such as food supplies, water use, biodiversity, energy demands and agro-economics

The minor wall-networks between monolignols and interlinked-phenolics predominantly affect biomass enzymatic digestibility in Miscanthus.

Science.gov (United States)

Li, Zhengru; Zhao, Chunqiao; Zha, Yi; Wan, Can; Si, Shengli; Liu, Fei; Zhang, Rui; Li, Fengcheng; Yu, Bin; Yi, Zili; Xu, Ning; Peng, Liangcai; Li, Qing

2014-01-01

Plant lignin is one of the major wall components that greatly contribute to biomass recalcitrance for biofuel production. In this study, total 79 representative Miscanthus germplasms were determined with wide biomass digestibility and diverse monolignol composition. Integrative analyses indicated that three major monolignols (S, G, H) and S/G ratio could account for lignin negative influence on biomass digestibility upon NaOH and H2SO4 pretreatments. Notably, the biomass enzymatic digestions were predominately affected by the non-KOH-extractable lignin and interlinked-phenolics, other than the KOH-extractable ones that cover 80% of total lignin. Furthermore, a positive correlation was found between the monolignols and phenolics at pnetworks against cellulases accessibility. The results indicated that the non-KOH-extractable lignin-complex should be the target either for cost-effective biomass pretreatments or for relatively simply genetic modification of plant cell walls in Miscanthus.

Preprocessing Moist Lignocellulosic Biomass for Biorefinery Feedstocks

Energy Technology Data Exchange (ETDEWEB)

Neal Yancey; Christopher T. Wright; Craig Conner; J. Richard Hess

2009-06-01

Biomass preprocessing is one of the primary operations in the feedstock assembly system of a lignocellulosic biorefinery. Preprocessing is generally accomplished using industrial grinders to format biomass materials into a suitable biorefinery feedstock for conversion to ethanol and other bioproducts. Many factors affect machine efficiency and the physical characteristics of preprocessed biomass. For example, moisture content of the biomass as received from the point of production has a significant impact on overall system efficiency and can significantly affect the characteristics (particle size distribution, flowability, storability, etc.) of the size-reduced biomass. Many different grinder configurations are available on the market, each with advantages under specific conditions. Ultimately, the capacity and/or efficiency of the grinding process can be enhanced by selecting the grinder configuration that optimizes grinder performance based on moisture content and screen size. This paper discusses the relationships of biomass moisture with respect to preprocessing system performance and product physical characteristics and compares data obtained on corn stover, switchgrass, and wheat straw as model feedstocks during Vermeer HG 200 grinder testing. During the tests, grinder screen configuration and biomass moisture content were varied and tested to provide a better understanding of their relative impact on machine performance and the resulting feedstock physical characteristics and uniformity relative to each crop tested.

Future challenges for woody biomass projections

NARCIS (Netherlands)

Schadauer, K.; Barreiro, Susana; Schelhaas, M.; McRoberts, Ronald E.

2017-01-01

Many drivers affect woody biomass projections including forest available for wood supply, market behavior, forest ownership, distributions by age and yield classes, forest typologies resulting from different edaphic, climatic conditions, and last but not least, how these factors are incorporated

The minor wall-networks between monolignols and interlinked-phenolics predominantly affect biomass enzymatic digestibility in Miscanthus.

Directory of Open Access Journals (Sweden)

Zhengru Li

Full Text Available Plant lignin is one of the major wall components that greatly contribute to biomass recalcitrance for biofuel production. In this study, total 79 representative Miscanthus germplasms were determined with wide biomass digestibility and diverse monolignol composition. Integrative analyses indicated that three major monolignols (S, G, H and S/G ratio could account for lignin negative influence on biomass digestibility upon NaOH and H2SO4 pretreatments. Notably, the biomass enzymatic digestions were predominately affected by the non-KOH-extractable lignin and interlinked-phenolics, other than the KOH-extractable ones that cover 80% of total lignin. Furthermore, a positive correlation was found between the monolignols and phenolics at p<0.05 level in the non-KOH-extractable only, suggesting their tight association to form the minor wall-networks against cellulases accessibility. The results indicated that the non-KOH-extractable lignin-complex should be the target either for cost-effective biomass pretreatments or for relatively simply genetic modification of plant cell walls in Miscanthus.

Potential transgenic routes to increase tree biomass.

Science.gov (United States)

Dubouzet, Joseph G; Strabala, Timothy J; Wagner, Armin

2013-11-01

Biomass is a prime target for genetic engineering in forestry because increased biomass yield will benefit most downstream applications such as timber, fiber, pulp, paper, and bioenergy production. Transgenesis can increase biomass by improving resource acquisition and product utilization and by enhancing competitive ability for solar energy, water, and mineral nutrients. Transgenes that affect juvenility, winter dormancy, and flowering have been shown to influence biomass as well. Transgenic approaches have increased yield potential by mitigating the adverse effects of prevailing stress factors in the environment. Simultaneous introduction of multiple genes for resistance to various stress factors into trees may help forest trees cope with multiple or changing environments. We propose multi-trait engineering for tree crops, simultaneously deploying multiple independent genes to address a set of genetically uncorrelated traits that are important for crop improvement. This strategy increases the probability of unpredictable (synergistic or detrimental) interactions that may substantially affect the overall phenotype and its long-term performance. The very limited ability to predict the physiological processes that may be impacted by such a strategy requires vigilance and care during implementation. Hence, we recommend close monitoring of the resultant transgenic genotypes in multi-year, multi-location field trials. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Factors affecting polyhydroxybutyrate accumulation in mesophyll cells of sugarcane and switchgrass

Science.gov (United States)

2014-01-01

Background Polyhydroxyalkanoates are linear biodegradable polyesters produced by bacteria as a carbon store and used to produce a range of bioplastics. Widespread polyhydroxyalkanoate production in C4 crops would decrease petroleum dependency by producing a renewable supply of biodegradable plastics along with residual biomass that could be converted into biofuels or energy. Increasing yields to commercial levels in biomass crops however remains a challenge. Previously, lower accumulation levels of the short side chain polyhydroxyalkanoate, polyhydroxybutyrate (PHB), were observed in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells in transgenic maize (Zea mays), sugarcane (Saccharum sp.), and switchgrass (Panicum virgatum L.) leading to a significant decrease in the theoretical yield potential. Here we explore various factors which might affect polymer accumulation in mesophyll cells, including targeting of the PHB pathway enzymes to the mesophyll plastid and their access to substrate. Results The small subunit of Rubisco from pea effectively targeted the PHB biosynthesis enzymes to both M and BS chloroplasts of sugarcane and switchgrass. PHB enzyme activity was retained following targeting to M plastids and was equivalent to that found in the BS plastids. Leaf total fatty acid content was not affected by PHB production. However, when fatty acid synthesis was chemically inhibited, polymer accumulated in M cells. Conclusions In this study, we provide evidence that access to substrate and neither poor targeting nor insufficient activity of the PHB biosynthetic enzymes may be the limiting factor for polymer production in mesophyll chloroplasts of C4 plants. PMID:25209261

Initial density affects biomass – density and allometric relationships in self-thinning populations of Fagopyrum esculentum

DEFF Research Database (Denmark)

Li, Lei; Weiner, Jacob; Zhou, Daowei

2013-01-01

and the biomass–density trajectory, we grew Fagopyrum esculentum populations at three high densities and measured shoot biomass, density and the height and diameter of individual plants at six harvests. * Initial density did not affect the slope of the log biomass–log density relationship, but there was a clear...... by the biomass density: the relationship between mass and volume. Initial density could affect this by altering allometric growth in a way that influences architectural compactness. An alternative hypothesis is that competition at higher initial density is more size symmetric, which has been shown to reduce...

Biomass recalcitrance: a multi-scale, multi-factor, and conversion-specific property.

Science.gov (United States)

McCann, Maureen C; Carpita, Nicholas C

2015-07-01

Recalcitrance of plant biomass to enzymatic hydrolysis for biofuel production is thought to be a property conferred by lignin or lignin-carbohydrate complexes. However, chemical catalytic and thermochemical conversion pathways, either alone or in combination with biochemical and fermentative pathways, now provide avenues to utilize lignin and to expand the product range beyond ethanol or butanol. To capture all of the carbon in renewable biomass, both lignin-derived aromatics and polysaccharide-derived sugars need to be transformed by catalysts to liquid hydrocarbons and high-value co-products. We offer a new definition of recalcitrance as those features of biomass which disproportionately increase energy requirements in conversion processes, increase the cost and complexity of operations in the biorefinery, and/or reduce the recovery of biomass carbon into desired products. The application of novel processing technologies applied to biomass reveal new determinants of recalcitrance that comprise a broad range of molecular, nanoscale, and macroscale factors. Sampling natural genetic diversity within a species, transgenic approaches, and synthetic biology approaches are all strategies that can be used to select biomass for reduced recalcitrance in various pretreatments and conversion pathways. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Functional Gene Discovery and Characterization of Genes and Alleles Affecting Wood Biomass Yield and Quality in Populus

Energy Technology Data Exchange (ETDEWEB)

Busov, Victor [Michigan Technological Univ., Houghton, MI (United States)

2017-02-12

Adoption of biofuels as economically and environmentally viable alternative to fossil fuels would require development of specialized bioenergy varieties. A major goal in the breeding of such varieties is the improvement of lignocellulosic biomass yield and quality. These are complex traits and understanding the underpinning molecular mechanism can assist and accelerate their improvement. This is particularly important for tree bioenergy crops like poplars (species and hybrids from the genus Populus), for which breeding progress is extremely slow due to long generation cycles. A variety of approaches have been already undertaken to better understand the molecular bases of biomass yield and quality in poplar. An obvious void in these undertakings has been the application of mutagenesis. Mutagenesis has been instrumental in the discovery and characterization of many plant traits including such that affect biomass yield and quality. In this proposal we use activation tagging to discover genes that can significantly affect biomass associated traits directly in poplar, a premier bioenergy crop. We screened a population of 5,000 independent poplar activation tagging lines under greenhouse conditions for a battery of biomass yield traits. These same plants were then analyzed for changes in wood chemistry using pyMBMS. As a result of these screens we have identified nearly 800 mutants, which are significantly (P<0.05) different when compared to wild type. Of these majority (~700) are affected in one of ten different biomass yield traits and 100 in biomass quality traits (e.g., lignin, S/G ration and C6/C5 sugars). We successfully recovered the position of the tag in approximately 130 lines, showed activation in nearly half of them and performed recapitulation experiments with 20 genes prioritized by the significance of the phenotype. Recapitulation experiments are still ongoing for many of the genes but the results are encouraging. For example, we have shown successful

Factors affecting fall down rates of dead aspen (Populus tremuloides) biomass following severe drought in west-central Canada.

Science.gov (United States)

Ted Hogg, Edward H; Michaelian, Michael

2015-05-01

Increases in mortality of trembling aspen (Populus tremuloides Michx.) have been recorded across large areas of western North America following recent periods of exceptionally severe drought. The resultant increase in standing, dead tree biomass represents a significant potential source of carbon emissions to the atmosphere, but the timing of emissions is partially driven by dead-wood dynamics which include the fall down and breakage of dead aspen stems. The rate at which dead trees fall to the ground also strongly influences the period over which forest dieback episodes can be detected by aerial surveys or satellite remote sensing observations. Over a 12-year period (2000-2012), we monitored the annual status of 1010 aspen trees that died during and following a severe regional drought within 25 study areas across west-central Canada. Observations of stem fall down and breakage (snapping) were used to estimate woody biomass transfer from standing to downed dead wood as a function of years since tree death. For the region as a whole, we estimated that >80% of standing dead aspen biomass had fallen after 10 years. Overall, the rate of fall down was minimal during the year following stem death, but thereafter fall rates followed a negative exponential equation with k = 0.20 per year. However, there was high between-site variation in the rate of fall down (k = 0.08-0.37 per year). The analysis showed that fall down rates were positively correlated with stand age, site windiness, and the incidence of decay fungi (Phellinus tremulae (Bond.) Bond. and Boris.) and wood-boring insects. These factors are thus likely to influence the rate of carbon emissions from dead trees following periods of climate-related forest die-off episodes. © 2014 Her Majesty the Queen in Right of Canada Global Change Biology © 2014 John Wiley & Sons Ltd Reproduced with the permission of the Minister of Natural Resources Canada.

Fruit production and branching density affect shoot and whole-tree wood to leaf biomass ratio in olive.

Science.gov (United States)

Rosati, Adolfo; Paoletti, Andrea; Al Hariri, Raeed; Famiani, Franco

2018-02-14

biomass ratio is likely to affect the canopy's ability to export carbon (i.e., towards fruits), as shoot wood to leaf biomass ratio affects the carbon export ability of the shoot. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Above-ground biomass of mangrove species. I. Analysis of models

Science.gov (United States)

Soares, Mário Luiz Gomes; Schaeffer-Novelli, Yara

2005-10-01

This study analyzes the above-ground biomass of Rhizophora mangle and Laguncularia racemosa located in the mangroves of Bertioga (SP) and Guaratiba (RJ), Southeast Brazil. Its purpose is to determine the best regression model to estimate the total above-ground biomass and compartment (leaves, reproductive parts, twigs, branches, trunk and prop roots) biomass, indirectly. To do this, we used structural measurements such as height, diameter at breast-height (DBH), and crown area. A combination of regression types with several compositions of independent variables generated 2.272 models that were later tested. Subsequent analysis of the models indicated that the biomass of reproductive parts, branches, and prop roots yielded great variability, probably because of environmental factors and seasonality (in the case of reproductive parts). It also indicated the superiority of multiple regression to estimate above-ground biomass as it allows researchers to consider several aspects that affect above-ground biomass, specially the influence of environmental factors. This fact has been attested to the models that estimated the biomass of crown compartments.

Exposure to biomass smoke as a risk factor for oesophageal and ...

African Journals Online (AJOL)

Exposure to biomass smoke as a risk factor for oesophageal and gastric cancer in low-income populations: A systematic review. Violet Kayamba, Douglas C. Heimburger, Douglas R. Morgan, Masharip Atadzhanov, Paul Kelly ...

Economic and policy factors driving adoption of institutional woody biomass heating systems in the United States

Science.gov (United States)

Jesse D. Young; Nathaniel M. Anderson; Helen T. Naughton; Katrina Mullan

2018-01-01

Abundant stocks of woody biomass that are associated with active forest management can be used as fuel for bioenergy in many applications. Though factors driving large-scale biomass use in industrial settings have been studied extensively, small-scale biomass combustion systems commonly used by institutions for heating have received less attention. A zero inflated...

Genetic loci simultaneously controlling lignin monomers and biomass digestibility of rice straw.

Science.gov (United States)

Hu, Zhen; Zhang, Guifen; Muhammad, Ali; Samad, Rana Abdul; Wang, Youmei; Walton, Jonathan D; He, Yuqing; Peng, Liangcai; Wang, Lingqiang

2018-02-26

Lignin content and composition are crucial factors affecting biomass digestibility. Exploring the genetic loci simultaneously affecting lignin-relevant traits and biomass digestibility is a precondition for lignin genetic manipulation towards energy crop breeding. In this study, a high-throughput platform was employed to assay the lignin content, lignin composition and biomass enzymatic digestibility of a rice recombinant inbred line population. Correlation analysis indicated that the absolute content of lignin monomers rather than lignin content had negative effects on biomass saccharification, whereas the relative content of p-hydroxyphenyl unit and the molar ratio of p-hydroxyphenyl unit to guaiacyl unit exhibited positive roles. Eight QTL clusters were identified and four of them affecting both lignin composition and biomass digestibility. The additive effects of clustered QTL revealed consistent relationships between lignin-relevant traits and biomass digestibility. Pyramiding rice lines containing the above four positive alleles for increasing biomass digestibility were selected and showed comparable lignin content, decreased syringyl or guaiacyl unit and increased molar percentage of p-hydroxyphenyl unit, the molar ratio of p-hydroxyphenyl unit to guaiacyl unit and sugar releases. More importantly, the lodging resistance and eating/cooking quality of pyramiding lines were not sacrificed, indicating the QTL information could be applied to select desirable energy rice lines.

Factors Influencing the Ignition and Burnout of a Single Biomass Particle

DEFF Research Database (Denmark)

Momenikouchaksaraei, Maryam; Kær, Søren Knudsen; Yin, Chungen

2011-01-01

Ignition and burnout of a single biomass particle were studied numerically. A one-dimensional particle combustion model was developed which is capable to simulate all the intraparticle conversion processes (drying, recondensation, devolatilization, char gasification/oxidation and heat/mass/moment......Ignition and burnout of a single biomass particle were studied numerically. A one-dimensional particle combustion model was developed which is capable to simulate all the intraparticle conversion processes (drying, recondensation, devolatilization, char gasification/oxidation and heat...... concentration were not very significant. The influences of these factors on particle burnout were much more remarkable than ignition behaviour....

Winter climate change affects growing-season soil microbial biomass and activity in northern hardwood forests

Science.gov (United States)

Jorge Durán; Jennifer L. Morse; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany C. Fisk; Myron J. Mitchell; Pamela H. Templer

2014-01-01

Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity...

Sugar-rich sweet sorghum is distinctively affected by wall polymer features for biomass digestibility and ethanol fermentation in bagasse.

Science.gov (United States)

Li, Meng; Feng, Shengqiu; Wu, Leiming; Li, Ying; Fan, Chunfen; Zhang, Rui; Zou, Weihua; Tu, Yuanyuan; Jing, Hai-Chun; Li, Shizhong; Peng, Liangcai

2014-09-01

Sweet sorghum has been regarded as a typical species for rich soluble-sugar and high lignocellulose residues, but their effects on biomass digestibility remain unclear. In this study, we examined total 63 representative sweet sorghum accessions that displayed a varied sugar level at stalk and diverse cell wall composition at bagasse. Correlative analysis showed that both soluble-sugar and dry-bagasse could not significantly affect lignocellulose saccharification under chemical pretreatments. Comparative analyses of five typical pairs of samples indicated that DP of crystalline cellulose and arabinose substitution degree of non-KOH-extractable hemicelluloses distinctively affected lignocellulose crystallinity for high biomass digestibility. By comparison, lignin could not alter lignocellulose crystallinity, but the KOH-extractable G-monomer predominately determined lignin negative impacts on biomass digestions, and the G-levels released from pretreatments significantly inhibited yeast fermentation. The results also suggested potential genetic approaches for enhancing soluble-sugar level and lignocellulose digestibility and reducing ethanol conversion inhibition in sweet sorghum. Copyright © 2014. Published by Elsevier Ltd.

Ranking of biomass pellets by integration of economic, environmental and technical factors

International Nuclear Information System (INIS)

Sultana, Arifa; Kumar, Amit

2012-01-01

Interest in biomass as a renewable energy source has increased recently in response to a need to reduce greenhouse gas (GHG) emissions. The objective of this study is to develop a multi-criteria assessment model and rank different biomass feedstock-based pellets, in terms of their suitability for use in large heat and power generation plants and show the importance of environmental, economical and technical factors in making decision about different pellets. Five pellet alternatives, each produced from a different sustainable biomass feedstock i.e., wood, straw, switchgrass, alfalfa and poultry litter, are ranked according to eleven criteria, using the Preference Ranking Organization Method for Enrichment and Evaluation (PROMETHEE). Both quantitative and qualitative criteria are considered, including environmental, technical and economic factors. Three scenarios, namely base case, environmental and economic, are developed by changing the weight assigned to different criteria. In the base case scenario, equal weights are assigned to each criterion. In the economic and environmental scenarios, more weight is given to the economic and environmental factors, respectively. Based on the PROMETHEE rankings, wood pellets are the best source of energy for all scenarios followed by switchgrass, straw, poultry litter and alfalfa pellets except economic scenario, where straw pellets held higher position than switchgrass pellets. Sensitivity analysis on weights, threshold values, preference function and production cost indicate that the ranking was stable. The ranking in all scenarios remained same when qualitative criteria were omitted from the model; this indicates the stronger influence of quantitative criteria. -- Highlights: ► This study ranks the pellets produced from different biomass feedstocks. ► The ranking of the pellets is based on technical, economical and environmental factors. ► This study uses PROMETHEE method for ranking pellets based on a range of

Factors Affecting Temporal and Spatial Variations of Microcystins in Gonghu Bay of Lake Taihu, with Potential Risk of Microcystin Contamination to Human Health

Directory of Open Access Journals (Sweden)

Qing Wang

2010-01-01

Full Text Available A field survey of the seasonal variation of microcystin (MC concentration was performed in Gonghu Bay (a total of 15 sampling sites of Lake Taihu from January to December 2008. Microcystis spp. biomass and intra-/extracellular MCs were significantly correlated with water temperature, suggesting the importance of temperature in cyanobacterial blooming in the lake. Higher MC concentration was found in summer and autumn, and peaks of Microcystis biomass and intra-/extracellular MC concentrations were all present in October. Spatially, risk of MCs was higher in littoral zones than in the pelagic area. There were significant correlations between N or P concentrations, and Microcystis biomass or MC content, suggesting that N and P levels affected MC production through influencing Microcystis biomass. Intra-/extracellular MCs and Microcystis biomass had negative exponential relationships with TN:TP, and the maximum values all occurred when TN:TP was <25. Multivariate analyses by pcca indicated that intra- and extracellular MC concentrations had better correlations with biological factors (such as Microcystis biomass and chl-a than physicochemical factors. The maximum concentration reached up to 17 µg/L MC-Lreq, considerably higher drinking water safety standard (1 µg/L recommended who. So it is necessary take measures reduce exposure risk of cyanobacterial toxins human beings.

Biomass pretreatment affects Ustilago maydis in producing itaconic acid

Directory of Open Access Journals (Sweden)

Klement Tobias

2012-04-01

Full Text Available Abstract Background In the last years, the biotechnological production of platform chemicals for fuel components has become a major focus of interest. Although ligno-cellulosic material is considered as suitable feedstock, the almost inevitable pretreatment of this recalcitrant material may interfere with the subsequent fermentation steps. In this study, the fungus Ustilago maydis was used to produce itaconic acid as platform chemical for the synthesis of potential biofuels such as 3-methyltetrahydrofuran. No studies, however, have investigated how pretreatment of ligno-cellulosic biomass precisely influences the subsequent fermentation by U. maydis. Thus, this current study aims to first characterize U. maydis in shake flasks and then to evaluate the influence of three exemplary pretreatment methods on the cultivation and itaconic acid production of this fungus. Cellulose enzymatically hydrolysed in seawater and salt-assisted organic-acid catalysed cellulose were investigated as substrates. Lastly, hydrolysed hemicellulose from fractionated beech wood was applied as substrate. Results U. maydis was characterized on shake flask level regarding its itaconic acid production on glucose. Nitrogen limitation was shown to be a crucial condition for the production of itaconic acid. For itaconic acid concentrations above 25 g/L, a significant product inhibition was observed. Performing experiments that simulated influences of possible pretreatment methods, U. maydis was only slightly affected by high osmolarities up to 3.5 osmol/L as well as of 0.1 M oxalic acid. The production of itaconic acid was achieved on pretreated cellulose in seawater and on the hydrolysed hemicellulosic fraction of pretreated beech wood. Conclusion The fungus U. maydis is a promising producer of itaconic acid, since it grows as single cells (yeast-like in submerged cultivations and it is extremely robust in high osmotic media and real seawater. Moreover, U. maydis can grow on

Steam-exploded biomass saccharification is predominately affected by lignocellulose porosity and largely enhanced by Tween-80 in Miscanthus.

Science.gov (United States)

Sun, Dan; Alam, Aftab; Tu, Yuanyuan; Zhou, Shiguang; Wang, Yanting; Xia, Tao; Huang, Jiangfeng; Li, Ying; Zahoor; Wei, Xiaoyang; Hao, Bo; Peng, Liangcai

2017-09-01

In this study, total ten Miscanthus accessions exhibited diverse cell wall compositions, leading to largely varied hexoses yields at 17%-40% (% cellulose) released from direct enzymatic hydrolysis of steam-exploded (SE) residues. Further supplied with 2% Tween-80 into the enzymatic digestion, the Mis7 accession showed the higher hexose yield by 14.8-fold than that of raw material, whereas the Mis10 had the highest hexoses yield at 77% among ten Miscanthus accessions. Significantly, this study identified four wall polymer features that negatively affect biomass saccharification as pbiomass enzymatic digestion. Hence, this study provides the potential strategy to enhance biomass saccharification using optimal biomass process technology and related genetic breeding in Miscanthus and beyond. Copyright © 2017 Elsevier Ltd. All rights reserved.

Plant biomass briquetting : a review

Energy Technology Data Exchange (ETDEWEB)

Song, Y. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Agricultural and Bioresource Engineering; Shenyang Agricultural Univ., Shenyang (China). College of Engineering; Tumuluru, J.S.; Tabil, L.; Meda, V. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Agricultural and Bioresource Engineering

2009-07-01

The technology of converting straws into briquettes for biofuel or energy applications was discussed with particular reference to the factors that affect the quality of briquette, such as the loading pressure, particle size of the chopped material, the preheating temperature, the moisture content and residence time of the die. The study results of briquetting materials such as corn stover, switch grass, alfalfa, cotton stalks and reed canary grass were also presented. The main briquetting related technologies, systems and equipment were also reviewed. The study showed that in order to produce an economically competitive feedstock, further research should be extended to other biomass materials as well as developing technologies to obtain a high quality briquette with better efficiencies from a wide range of biomass materials.

Exposure to biomass smoke as a risk factor for oesophageal and gastric cancer in low-income populations: A systematic review.

Science.gov (United States)

Kayamba, Violet; Heimburger, Douglas C; Morgan, Douglas R; Atadzhanov, Masharip; Kelly, Paul

2017-06-01

Upper gastrointestinal cancers contribute significantly to cancer-related morbidity and mortality in sub-Saharan Africa, but they continue to receive limited attention. The high incidence in young adults remains unexplained, and the risk factors have not been fully described. A literature search was conducted using the electronic database PubMed. Beginning from January 1980 to February 2016, all articles evaluating biomass smoke exposure with oesophageal and gastric cancer were reviewed. Over 70% of the African population relies on biomass fuel, meaning most Africans are exposed to biomass smoke throughout their lives. Cigarette smoke is an established risk factor for upper gastrointestinal cancers, and some of its carcinogenic constituents are also present in biomass smoke. We found eight case-control studies reporting associations between exposure to biomass smoke and oesophageal cancer, and two linking biomass smoke to gastric cancer. All of these papers reported significant positive associations between exposure and cancer risk. Further research is needed in order to fully define the constituents of biomass smoke, which could each have varying specific and synergistic or independent contributions to the development of upper gastrointestinal cancers. Exposure to biomass smoke is an environmental factor influencing the development of upper gastrointestinal cancers, especially in low-resource settings.

Emission factors from biomass burning in three types of appliances: fireplace, woodstove and pellet stove

Science.gov (United States)

Duarte, Márcio; Vicente, Estela; Calvo, Ana; Nunes, Teresa; Tarelho, Luis; Alves, Célia

2014-05-01

In the last years, the importance of biomass fuels has increased mainly for two reasons. One of them is the effort to control the emissions of greenhouse gases, and on the other hand, the increasing costs associated with fossil fuels. Besides that, biomass burning is now recognised as one of the major sources contributing to high concentrations of particulate matter, especially during winter time. Southern European countries have a lack of information regarding emission profiles from biomass burning. Because of that, in most source apportionment studies, the information used comes from northern and alpine countries, whose combustion appliances, fuels and habits are different from those in Mediterranean countries. Due to this lack of information, series of tests using different types of equipment, as well as fuels, were carried out in order to obtain emission profiles and emission factors that correspond to the reality in southern European countries. Tests involved three types of biomass appliances used in Portugal, a fireplace, a woodstove and a modern pellet stove. Emission factors (mg.kg-1 fuel, dry basis) for CO, THC and PM10 were obtained. CO emission factors ranged from 38, for pine on the woodstove, to 84 for eucalyptus in the fireplace. THC emissions were between 4 and 24, for pine in the woodstove and eucalyptus in the fireplace, respectively. PM10 emission factors were in the range from 3.99, for pine in the woodstove, to 17.3 for eucalyptus in the fireplace. On average, the emission factors obtained for the fireplace are 1.5 (CO) to 4 (THC) times higher than those of the woodstove. The fireplace has emission factors for CO, THC and PM10 10, 35 and 32 times, respectively, higher than the pellet stove.

Pathogenic mechanisms in chronic obstructive pulmonary disease due to biomass smoke exposure.

Science.gov (United States)

Silva, Rafael; Oyarzún, Manuel; Olloquequi, Jordi

2015-06-01

Chronic obstructive pulmonary disease (COPD) mortality and morbidity have increased significantly worldwide in recent decades. Although cigarette smoke is still considered the main risk factor for the development of the disease, estimates suggest that between 25% and 33% of COPD patients are non-smokers. Among the factors that may increase the risk of developing COPD, biomass smoke has been proposed as one of the most important, affecting especially women and children in developing countries. Despite the epidemiological evidence linking exposure to biomass smoke with adverse health effects, the specific cellular and molecular mechanisms by which this pollutant can be harmful for the respiratory and cardiovascular systems remain unclear. In this article we review the main pathogenic mechanisms proposed to date that make biomass smoke one of the major risk factors for COPD. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

Urban vs. rural factors that affect adult asthma.

Science.gov (United States)

Jie, Yu; Isa, Zaleha Md; Jie, Xu; Ju, Zhang Long; Ismail, Noor Hassim

2013-01-01

In this review, our aim was to examine the influence of geographic variations on asthma prevalence and morbidity among adults, which is important for improving our understanding, identifying the burden, and for developing and implementing interventions aimed at reducing asthma morbidity. Asthma is a complex inflammatory disease of multifactorial origin, and is influenced by both environmental and genetic factors. The disparities in asthma prevalence and morbidity among the world's geographic locations are more likely to be associated with environmental exposures than genetic differences. In writing this article, we found that the indoor factors most consistently associated with asthma and asthma-related symptoms in adults included fuel combustion, mold growth, and environmental tobacco smoke in both urban and rural areas. Asthma and asthma-related symptoms occurred more frequently in urban than in rural areas, and that difference correlated with environmental risk exposures, SES, and healthcare access. Environmental risk factors to which urban adults were more frequently exposed than rural adults were dust mites,high levels of vehicle emissions, and a westernized lifestyle.Exposure to indoor biological contaminants in the urban environment is common.The main risk factors for developing asthma in urban areas are atopy and allergy to house dust mites, followed by allergens from animal dander. House dust mite exposure may potentially explain differences in diagnosis of asthma prevalence and morbidity among adults in urban vs. rural areas. In addition, the prevalence of asthma morbidity increases with urbanization. High levels of vehicle emissions,Western lifestyles and degree of urbanization itself, may affect outdoor and thereby indoor air quality. In urban areas, biomass fuels have been widely replaced by cleaner energy sources at home, such as gas and electricity, but in most developing countries, coal is still a major source of fuel for cooking and heating

Factors Affecting University Library Website Design

OpenAIRE

Kim, Yongi-Mi; University of Oklahoma

2011-01-01

Existing studies have extensively explored factors that affect users’ intentions to use university library website resources (ULWR); yet little attention has been given to factors affecting university library website design. This paper investigates factors that affect university library website design and assesses the success of the university library website from both designers’ and users’ perspectives. The findings show that when planning a website, university web designers consider univers...

Biomass yield potential of short-rotation hardwoods in the Great Plains

Energy Technology Data Exchange (ETDEWEB)

Geyer, W A [Kansas State Univ., Manhattan, KS (USA). Dept. of Forestry

1989-01-01

Wood for fuel has increased in importance. Its primary use in the world is for energy, increasingly coming from wood wastes and new biomass sources. One solution to the potential problem of using high-quality trees for fuel could be woody biomass grown under a short-rotation intensive culture system. Species, size, age and spacing are factors that affect biomass production of broadleafed trees. Trials of several species grown at close spacing (0.3 m x 0.3 m) and cut at various ages are described and related to the growth and yield of more conventionally spaced plantings on an alluvial site in eastern Kansas. (author).

Emissions of fine particulate nitrated phenols from the burning of five common types of biomass

International Nuclear Information System (INIS)

Wang, Xinfeng; Gu, Rongrong; Wang, Liwei; Xu, Wenxue; Zhang, Yating; Chen, Bing; Li, Weijun; Xue, Likun; Chen, Jianmin; Wang, Wenxing

2017-01-01

Nitrated phenols are among the major constituents of brown carbon and affect both climates and ecosystems. However, emissions from biomass burning, which comprise one of the most important primary sources of atmospheric nitrated phenols, are not well understood. In this study, the concentrations and proportions of 10 nitrated phenols, including nitrophenols, nitrocatechols, nitrosalicylic acids, and dinitrophenol, in fine particles from biomass smoke were determined under three different burning conditions (flaming, weakly flaming, and smoldering) with five common types of biomass (leaves, branches, corncob, corn stalk, and wheat straw). The total abundances of fine nitrated phenols produced by biomass burning ranged from 2.0 to 99.5 μg m −3 . The compositions of nitrated phenols varied with biomass types and burning conditions. 4-nitrocatechol and methyl nitrocatechols were generally most abundant, accounting for up to 88–95% of total nitrated phenols in flaming burning condition. The emission ratios of nitrated phenols to PM 2.5 increased with the completeness of combustion and ranged from 7 to 45 ppmm and from 239 to 1081 ppmm for smoldering and flaming burning, respectively. The ratios of fine nitrated phenols to organic matter in biomass burning aerosols were comparable to or lower than those in ambient aerosols affected by biomass burning, indicating that secondary formation contributed to ambient levels of fine nitrated phenols. The emission factors of fine nitrated phenols from flaming biomass burning were estimated based on the measured mass fractions and the PM 2.5 emission factors from literature and were approximately 0.75–11.1 mg kg −1 . According to calculations based on corn and wheat production in 31 Chinese provinces in 2013, the total estimated emission of fine nitrated phenols from the burning of corncobs, corn stalks, and wheat straw was 670 t. This work highlights the apparent emission of methyl nitrocatechols from biomass burning

Effect of small-scale biomass gasification at the state of refractory lining the fixed bed reactor

Energy Technology Data Exchange (ETDEWEB)

Janša, Jan, E-mail: jan.jansa@vsb.cz; Peer, Vaclav, E-mail: vaclav.peer@vsb.cz; Pavloková, Petra, E-mail: petra.pavlokova@vsb.cz [VŠB – Technical University of Ostrava, Energy Research Center, 708 33 Ostrava (Czech Republic)

2016-06-30

The article deals with the influence of biomass gasification on the condition of the refractory lining of a fixed bed reactor. The refractory lining of the gasifier is one part of the device, which significantly affects the operational reliability and durability. After removing the refractory lining of the gasifier from the experimental reactor, there was done an assessment how gasification of different kinds of biomass reflected on its condition in terms of the main factors affecting its life. Gasification of biomass is reflected on the lining, especially through sticking at the bottom of the reactor. Measures for prolonging the life of lining consist in the reduction of temperature in the reactor, in this case, in order to avoid ash fusion biomass which it is difficult for this type of gasifier.

Analysis on biomass and productivity of epilithic algae and their relations to environmental factors in the Gufu River basin, Three Gorges Reservoir area, China.

Science.gov (United States)

Ge, Jiwen; Wu, Shuyuan; Touré, Dado; Cheng, Lamei; Miao, Wenjie; Cao, Huafen; Pan, Xiaoying; Li, Jianfeng; Yao, Minmin; Feng, Liang

2017-12-01

The main purpose of this study conducted from August 2010 was to find biomass and productivity of epilithic algae and their relations to environmental factors and try to explore the restrictive factors affecting the growth of algae in the Gufu River, the one of the branches of Xiangxi River located in the Three Gorges Reservoir of the Yangtze River, Hubei Province, Central China. An improved method of in situ primary productivity measurement was utilized to estimate the primary production of the epilithic algae. It was shown that in rivers, lakes, and reservoirs, algae are the main primary producers and have a central role in the ecosystem. Chlorophyll a concentration and ash-free dry mass (AFDM) were estimated for epilithic algae of the Gufu River basin in Three Gorges Reservoir area. Environmental factors in the Gufu River ecosystem highlighted differences in periphyton chlorophyll a ranging from 1.49 mg m -2 (origin) to 69.58 mg m -2 (terminal point). The minimum and maximum gross primary productivity of epilithic algae were 96.12 and 1439.89 mg C m -2  day -1 , respectively. The mean net primary productivity was 290.24 mg C m -2  day -1 . The mean autotrophic index (AFDM:chlorophyll a) was 407.40. The net primary productivity, community respiration ratio (P/R ratio) ranged from 0.98 to 9.25 with a mean of 2.76, showed that autotrophic productivity was dominant in the river. Relationship between physicochemical characteristics and biomass was discussed through cluster and stepwise regression analysis which indicated that altitude, total nitrogen (TN), NO 3 - -N, and NH 4 + -N were significant environmental factors affecting the biomass of epilithic algae. However, a negative logarithmic relationship between altitude and the chlorophyll a of epilithic algae was high. The results also highlighted the importance of epilithic algae in maintaining the Gufu River basin ecosystems health.

Combining woody biomass for combustion with green waste composting: Effect of removal of woody biomass on compost quality.

Science.gov (United States)

Vandecasteele, Bart; Boogaerts, Christophe; Vandaele, Elke

2016-12-01

The question was tackled on how the green waste compost industry can optimally apply the available biomass resources for producing both bioenergy by combustion of the woody fraction, and high quality soil improvers as renewable sources of carbon and nutrients. Compost trials with removal of woody biomass before or after composting were run at 9 compost facilities during 3 seasons to include seasonal variability of feedstock. The project focused on the changes in feedstock and the effect on the end product characteristics (both compost and recovered woody biomass) of this woody biomass removal. The season of collection during the year clearly affected the biochemical and chemical characteristics of feedstock, woody biomass and compost. On one hand the effect of removal of the woody fraction before composting did not significantly affect compost quality when compared to the scenario where the woody biomass was sieved from the compost at the end of the composting process. On the other hand, quality of the woody biomass was not strongly affected by extraction before or after composting. The holocellulose:lignin ratio was used in this study as an indicator for (a) the decomposition potential of the feedstock mixture and (b) to assess the stability of the composts at the end of the process. Higher microbial activity in green waste composts (indicated by higher oxygen consumption) and thus a lower compost stability resulted in higher N immobilization in the compost. Removal of woody biomass from the green waste before composting did not negatively affect the compost quality when more intensive composting was applied. The effect of removal of the woody fraction on the characteristics of the green waste feedstock and the extracted woody biomass is depending on the season of collection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Yield and grain quality of spring barley as affected by biomass formation at early growth stages

Czech Academy of Sciences Publication Activity Database

Křen, J.; Klem, Karel; Svobodová, I.; Míša, P.; Neudert, L.

2014-01-01

Roč. 60, č. 5 (2014), s. 221-227 ISSN 1214-1178 R&D Projects: GA MZe QI111A133 Keywords : Hordeum vulgare L * above-ground biomass * tillering * grain yield formation * grain protein content Subject RIV: EH - Ecology, Behaviour Impact factor: 1.226, year: 2014

Biomass and biomass water use efficiency in oilseed crop (Brassica juncea L.) under semi-arid microenvironments

International Nuclear Information System (INIS)

Adak, Tarun; Kumar, Gopal; Chakravarty, N.V.K.; Katiyar, R.K.; Deshmukh, P.S.; Joshi, H.C.

2013-01-01

Biomass production in arid and semi-arid regions requires a special attention owing to spatiotemporal scarcity of irrigation water wherein improved water use efficiency (WUE) of the crop is targeted. Under field conditions, the crop undergoes dynamic changes in near ground or within-canopy microenvironments. This changed microclimatic condition may have an impact on phenological response of the oilseed crop which in turn would affect biomass productivity, economic seed yield and water use efficiency of the crop. Henceforth, quantification of biomass production and its WUE of oilseed Brassica crop is essentially required owing to have better understanding of the crop water requirement under the era of climate change. Following a 2 years field experiment, it was revealed that the changes in leaf area index were explained by about 68–74%. The best fit polynomial third order regression analysis indicated >93% prediction in biomass production as a function of time factor. Improved biomass partitioning into economic sinks was also observed. Small scale change in near ground microenvironment may reduce the prediction of biomass variability to the extent of 3%. The mean ET variations were observed as 2.4, 1.5 and 3.2 mm day −1 during the critical phenological stages. Mean seed yield, biomass WUE and seed yield WUE ranged between 2.71 and 2.87 Mg ha −1 , 11.4 and 13.1 g m −2 mm −1 and 19.3 and 22.9 kg ha −1 mm −1 respectively. Variations in both biomass and seed yield water use efficiencies due to small scale change in near ground microclimates were revealed. -- Highlights: ► Assessing biomass productivity and its water use efficiency under arid and semi-arid regions is important. ► Under field conditions, the crop undergoes dynamic changes in near ground or within-canopy microenvironments. ► We have estimated changes in seasonal ET, within-canopy micrometeorological dynamics. ► Biomass productivity, partitioning and water use efficiencies were

Does chronic nitrogen deposition during biomass growth affect atmospheric emissions from biomass burning?

Science.gov (United States)

Michael R Giordano; Joey Chong; David R Weise; Akua A Asa-Awuku

2016-01-01

Chronic nitrogen deposition has measureable impacts on soil and plant health.We investigate burning emissions from biomass grown in areas of high and low NOx deposition. Gas and aerosolphase emissions were measured as a function of photochemical aging in an environmental chamber at UC-Riverside. Though aerosol chemical speciation was not...

Structural evolution of biomass char and its effect on the gasification rate

International Nuclear Information System (INIS)

Fatehi, Hesameddin; Bai, Xue-Song

2017-01-01

Highlights: • A comprehensive model was developed to describe the evolution of biomass char structure. • An effectiveness factor was used to account for the intra-particle chemical and physical processes. • The effect of the structural evolution of the multi-pore structure on biomass char reactivity was analyzed. • The multi-pore model yields results in satisfactory agreement with experiments. - Abstract: The evolution of char porous structure can affect the conversion rate of the char by affecting the intra-particle transport, especially in the zone II conversion regime. A multi-pore model based on the capillary pore theory is developed to take into account different conversion rates for pores with different radii. The model is valid for biomass chars produced under relatively low heating rates, when the original beehive structure of the biomass is not destroyed during the pyrolysis stage. The contribution of different pores with different radius is taken into account using an effectiveness factor presented for each pore radius with respect to different reactions. As the char conversion proceeds, the pore enlargement increases the contribution of micro-pores; consequently the effective surface area will increase. The increase in the effective surface area leads to an increased reactivity of char during the entire conversion process. This model is used to analyze the steam gasification process of biomass char of centimeter sizes. The results from the present multi-pore model are in better agreement with experimental data than those from a corresponding single pore model. Since the multi-pore model accommodates the detailed intra-particle transport, it is a useful basis toward developing a more predictive model for biomass char gasification.

Solar Program Assessment: Environmental Factors - Fuels from Biomass.

Science.gov (United States)

Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

The purpose of this report is to present and prioritize the major environmental issues associated with the further development of biomass production and biomass conversion systems. To provide a background for this environmental analysis, the basic concepts of the technology are reviewed, as are resource requirements. The potential effects of this…

Factors affecting nuclear development

International Nuclear Information System (INIS)

Stevens, G.H.; Girouard, P.

1995-01-01

Among the factors affecting nuclear development, some depend more or less on public authorities, but many are out of public authorities control (foreign policies, market and deregulation, socials and environmental impacts, public opinion). As far as possible, the following study tries to identify those factors. (D.L.). 2 photos

Factors affecting construction performance: exploratory factor analysis

Science.gov (United States)

Soewin, E.; Chinda, T.

2018-04-01

The present work attempts to develop a multidimensional performance evaluation framework for a construction company by considering all relevant measures of performance. Based on the previous studies, this study hypothesizes nine key factors, with a total of 57 associated items. The hypothesized factors, with their associated items, are then used to develop questionnaire survey to gather data. The exploratory factor analysis (EFA) was applied to the collected data which gave rise 10 factors with 57 items affecting construction performance. The findings further reveal that the items constituting ten key performance factors (KPIs) namely; 1) Time, 2) Cost, 3) Quality, 4) Safety & Health, 5) Internal Stakeholder, 6) External Stakeholder, 7) Client Satisfaction, 8) Financial Performance, 9) Environment, and 10) Information, Technology & Innovation. The analysis helps to develop multi-dimensional performance evaluation framework for an effective measurement of the construction performance. The 10 key performance factors can be broadly categorized into economic aspect, social aspect, environmental aspect, and technology aspects. It is important to understand a multi-dimension performance evaluation framework by including all key factors affecting the construction performance of a company, so that the management level can effectively plan to implement an effective performance development plan to match with the mission and vision of the company.

Biomass for biorefining: Resources, allocation, utilization, and policies

Science.gov (United States)

The importance of biomass in the development of renewable energy, the availability and allocation of biomass, its preparation for use in biorefineries, and the policies affecting biomass are discussed in this chapter. Bioenergy development will depend on maximizing the amount of biomass obtained fro...

Factors Affecting Medical Service Quality.

Science.gov (United States)

Mosadeghrad, Ali Mohammad

2014-02-01

A better understanding of factors influencing quality of medical service can pinpoint better strategies for quality assurance in medical services. This study aimed to identify factors affecting the quality of medical services provided by Iranian physicians. Exploratory in-depth individual interviews were conducted with sixty-four physicians working in various medical institutions in Iran. Individual, organizational and environmental factors enhance or inhibit the quality of medical services. Quality of medical services depends on the personal factors of the physician and patient, and factors pertaining to the healthcare setting and the broader environment. Differences in internal and external factors such as availability of resources, patient cooperation and collaboration among providers affect the quality of medical services and patient outcomes. Supportive leadership, proper planning, education and training and effective management of resources and processes improve the quality of medical services. This article contributes to healthcare theory and practice by developing a conceptual framework for understanding factors that influence medical services quality.

Examining the Factors Affecting Student Dropout

Directory of Open Access Journals (Sweden)

Fethi Ahmet INAN

2006-07-01

Full Text Available This study examined the factors affecting student dropouts in an online certificate program. In this research, a combination of quantitative and qualitative methods was used. Online Course Dropout Survey was developed and used to determine which factors affect student attrition from the program. The dropout survey was sent by e-mail to 98 students who had dropped the program. Twenty-six students returned the survey. The findings show that the most important factor affecting student retention is finding sufficient time to study. Having personal problems and affordability of the program took second and third place.

Impact of environmental conditions on biomass yield, quality, and bio-mitigation capacity of Saccharina latissima

DEFF Research Database (Denmark)

Bruhn, Annette; Tørring, Ditte Bruunshøj; Thomsen, Marianne

2016-01-01

of the EU Marine Strategy Framework Directive. Environmental factors determine the yield and quality of the cultivated seaweed biomass and, in return, the seaweed aquaculture affects the marine environment by nutrient assimilation. Consequently, site selection is critical for obtaining optimal biomass yield...... environmental conditions and cultivation success. The biomass yields fluctuated 10-fold between sites due to local variations in light and nutrient availability.Yields were generally low, i.e. up to 510 g fresh weight (FW) per meter seeded line; however, the dry matter contents of protein and high...

Factors Controlling Changes in Epilithic Algal Biomass in the Mountain Streams of Subtropical Taiwan.

Directory of Open Access Journals (Sweden)

Yi-Ming Kuo

Full Text Available In upstream reaches, epilithic algae are one of the major primary producers and their biomass may alter the energy flow of food webs in stream ecosystems. However, the overgrowth of epilithic algae may deteriorate water quality. In this study, the effects of environmental variables on epilithic algal biomass were examined at 5 monitoring sites in mountain streams of the Wuling basin of subtropical Taiwan over a 5-year period (2006-2011 by using a generalized additive model (GAM. Epilithic algal biomass and some variables observed at pristine sites obviously differed from those at the channelized stream with intensive agricultural activity. The results of the optimal GAM showed that water temperature, turbidity, current velocity, dissolved oxygen (DO, pH, and ammonium-N (NH4-N were the main factors explaining seasonal variations of epilithic algal biomass in the streams. The change points of smoothing curves for velocity, DO, NH4-N, pH, turbidity, and water temperature were approximately 0.40 m s-1, 8.0 mg L-1, 0.01 mg L-1, 8.5, 0.60 NTU, and 15°C, respectively. When aforementioned variables were greater than relevant change points, epilithic algal biomass was increased with pH and water temperature, and decreased with water velocity, DO, turbidity, and NH4-N. These change points may serve as a framework for managing the growth of epilithic algae. Understanding the relationship between environmental variables and epilithic algal biomass can provide a useful approach for maintaining the functioning in stream ecosystems.

Factors affecting surf zone phytoplankton production in Southeastern North Carolina, USA

KAUST Repository

Cahoon, Lawrence B.

2017-07-15

Abstract: The biomass and productivity of primary producers in the surf zone of the ocean beach at Wrightsville Beach, North Carolina, USA, were measured during all seasons, along with environmental parameters and nutrient levels. Variation in biomass (chlorophyll a) was associated with temperature. Primary production (PP), measured by in situ 14-C incubations, was a function of chlorophyll a, tide height at the start of incubations, and rainfall in the preceding 24-hr period. Biomass-normalized production (PB) was also a function of tide height and rainfall in the preceding 24-hr period. We interpreted these results as evidence of surf production 1) as combined contributions of phytoplankton and suspended benthic microalgae, which may confound application of simple P-E models to surf zone production, and 2) being regulated by nutrient source/supply fluctuations independently from other factors. Surf zone biomass and production levels are intermediate between relatively high estuarine values and much lower coastal ocean values. Surf zone production may represent an important trophic connection between these two important ecosystems.

Factors affecting surf zone phytoplankton production in Southeastern North Carolina, USA

KAUST Repository

Cahoon, Lawrence B.; Bugica, Kalman; Wooster, Michael K.; Dickens, Amanda Kahn

2017-01-01

Abstract: The biomass and productivity of primary producers in the surf zone of the ocean beach at Wrightsville Beach, North Carolina, USA, were measured during all seasons, along with environmental parameters and nutrient levels. Variation in biomass (chlorophyll a) was associated with temperature. Primary production (PP), measured by in situ 14-C incubations, was a function of chlorophyll a, tide height at the start of incubations, and rainfall in the preceding 24-hr period. Biomass-normalized production (PB) was also a function of tide height and rainfall in the preceding 24-hr period. We interpreted these results as evidence of surf production 1) as combined contributions of phytoplankton and suspended benthic microalgae, which may confound application of simple P-E models to surf zone production, and 2) being regulated by nutrient source/supply fluctuations independently from other factors. Surf zone biomass and production levels are intermediate between relatively high estuarine values and much lower coastal ocean values. Surf zone production may represent an important trophic connection between these two important ecosystems.

Factors affecting surf zone phytoplankton production in Southeastern North Carolina, USA

Science.gov (United States)

Cahoon, Lawrence B.; Bugica, Kalman; Wooster, Michael K.; Dickens, Amanda Kahn

2017-09-01

The biomass and productivity of primary producers in the surf zone of the ocean beach at Wrightsville Beach, North Carolina, USA, were measured during all seasons, along with environmental parameters and nutrient levels. Variation in biomass (chlorophyll a) was associated with temperature. Primary production (PP), measured by in situ 14-C incubations, was a function of chlorophyll a, tide height at the start of incubations, and rainfall in the preceding 24-hr period. Biomass-normalized production (PB) was also a function of tide height and rainfall in the preceding 24-hr period. We interpreted these results as evidence of surf production 1) as combined contributions of phytoplankton and suspended benthic microalgae, which may confound application of simple P-E models to surf zone production, and 2) being regulated by nutrient source/supply fluctuations independently from other factors. Surf zone biomass and production levels are intermediate between relatively high estuarine values and much lower coastal ocean values. Surf zone production may represent an important trophic connection between these two important ecosystems.

Biomass estimates of freshwater zooplankton from length-carbon regression equations

Directory of Open Access Journals (Sweden)

Patrizia COMOLI

2000-02-01

Full Text Available We present length/carbon regression equations of zooplankton species collected from Lake Maggiore (N. Italy during 1992. The results are discussed in terms of the environmental factors, e.g. food availability, predation, controlling biomass production of particle- feeders and predators in the pelagic system of lakes. The marked seasonality in the length-standardized carbon content of Daphnia, and its time-specific trend suggest that from spring onward food availability for Daphnia population may be regarded as a simple decay function. Seasonality does not affect the carbon content/unit length of the two predator Cladocera Leptodora kindtii and Bythotrephes longimanus. Predation is probably the most important regulating factor for the seasonal dynamics of their carbon biomass. The existence of a constant factor to convert the diameter of Conochilus colonies into carbon seems reasonable for an organism whose population comes on quickly and just as quickly disappears.

Does species richness affect fine root biomass and production in young forest plantations?

Science.gov (United States)

Domisch, Timo; Finér, Leena; Dawud, Seid Muhie; Vesterdal, Lars; Raulund-Rasmussen, Karsten

2015-02-01

Tree species diversity has been reported to increase forest ecosystem above-ground biomass and productivity, but little is known about below-ground biomass and production in diverse mixed forests compared to single-species forests. For testing whether species richness increases below-ground biomass and production and thus complementarity between forest tree species in young stands, we determined fine root biomass and production of trees and ground vegetation in two experimental plantations representing gradients in tree species richness. Additionally, we measured tree fine root length and determined species composition from fine root biomass samples with the near-infrared reflectance spectroscopy method. We did not observe higher biomass or production in mixed stands compared to monocultures. Neither did we observe any differences in tree root length or fine root turnover. One reason for this could be that these stands were still young, and canopy closure had not always taken place, i.e. a situation where above- or below-ground competition did not yet exist. Another reason could be that the rooting traits of the tree species did not differ sufficiently to support niche differentiation. Our results suggested that functional group identity (i.e. conifers vs. broadleaved species) can be more important for below-ground biomass and production than the species richness itself, as conifers seemed to be more competitive in colonising the soil volume, compared to broadleaved species.

Low Calorie Diet Affects Aging-Related Factors

Science.gov (United States)

... Current Issue Past Issues Research News From NIH Low Calorie Diet Affects Aging-Related Factors Past Issues / ... to learn more about the effects of sustained low-calorie diets in humans on factors affecting aging. ...

Electricity from biomass

International Nuclear Information System (INIS)

Price, B.

1998-11-01

Electricity from biomass assesses the potential of biomass electricity for displacing other more polluting power sources and providing a relatively clean and ecologically friendly source of energy; discusses its environmental and economic effects, while analysing political and institutional initiatives and constraints; evaluates key factors, such as energy efficiency, economics, decentralisation and political repurcussions; considers the processes and technologies employed to produce electricity from biomass; and discusses the full range of incentives offered to producers and potential producers and the far-reaching implications it could have for industry, society and the environment. (author)

Forest biomass variation in Southernmost Brazil: the impact of Araucaria trees.

Science.gov (United States)

Rosenfield, Milena Fermina; Souza, Alexandre F

2014-03-01

A variety of environmental and biotic factors determine vegetation growth and affect plant biomass accumulation. From temperature to species composition, aboveground biomass storage in forest ecosystems is influenced by a number of variables and usually presents a high spatial variability. With this focus, the aim of the study was to evaluate the variables affecting live aboveground forest biomass (AGB) in Subtropical Moist Forests of Southern Brazil, and to analyze the spatial distribution of biomass estimates. Data from a forest inventory performed in the State of Rio Grande do Sul, Southern Brazil, was used in the present study. Thirty-eight 1-ha plots were sampled and all trees with DBH > or = 9.5cm were included for biomass estimation. Values for aboveground biomass were obtained using published allometric equations. Environmental and biotic variables (elevation, rainfall, temperature, soils, stem density and species diversity) were obtained from the literature or calculated from the dataset. For the total dataset, mean AGB was 195.2 Mg/ha. Estimates differed between Broadleaf and Mixed Coniferous-Broadleaf forests: mean AGB was lower in Broadleaf Forests (AGB(BF)=118.9 Mg/ha) when compared to Mixed Forests (AGB(MF)=250.3 Mg/ha). There was a high spatial and local variability in our dataset, even within forest types. This condition is normal in tropical forests and is usually attributed to the presence of large trees. The explanatory multiple regressions were influenced mainly by elevation and explained 50.7% of the variation in AGB. Stem density, diversity and organic matter also influenced biomass variation. The results from our study showed a positive relationship between aboveground biomass and elevation. Therefore, higher values of AGB are located at higher elevations and subjected to cooler temperatures and wetter climate. There seems to be an important contribution of the coniferous species Araucaria angustifolia in Mixed Forest plots, as it presented

Seasonal variability of microbial biomass phosphorus in urban soils.

Science.gov (United States)

Halecki, W; Gąsiorek, M

2015-01-01

Urban soils have been formed through human activities. Seasonal evaluation with time-control procedure are essential for plant, and activity of microorganisms. Therefore, these processes are crucial in the urban area due to geochemical changes in the past years. The purpose of this study was to investigate the changes of content of microbial biomass phosphorus (P) in the top layer of soils throughout the season. In this research, the concentration of microbial biomass P ranged from 0.01 to 6.29 mg·kg(-1). We used single-factor repeated-measure analysis of variance to test the effect of season on microbial biomass P content of selected urban soils. We found no statistically significant differences between the concentration of microbial biomass P in the investigated urban and sub-urban soils during the growing season. This analysis explicitly recognised that environmental urban conditions are steady. Specifically, we have studied how vegetation seasonality and ability of microbial biomass P are useful for detecting quality deviations, which affect the equilibrium of urban soil. In conclusion, seasonal variability of the stringency of assurance across the different compounds of soil reveals, as expected, the stable condition of the urban soils. Seasonal responses in microbial biomass P under urban soil use should establish a framework as a reference to the activity of the microorganisms. Copyright © 2014 Elsevier B.V. All rights reserved.

Emissions of fine particulate nitrated phenols from the burning of five common types of biomass.

Science.gov (United States)

Wang, Xinfeng; Gu, Rongrong; Wang, Liwei; Xu, Wenxue; Zhang, Yating; Chen, Bing; Li, Weijun; Xue, Likun; Chen, Jianmin; Wang, Wenxing

2017-11-01

Nitrated phenols are among the major constituents of brown carbon and affect both climates and ecosystems. However, emissions from biomass burning, which comprise one of the most important primary sources of atmospheric nitrated phenols, are not well understood. In this study, the concentrations and proportions of 10 nitrated phenols, including nitrophenols, nitrocatechols, nitrosalicylic acids, and dinitrophenol, in fine particles from biomass smoke were determined under three different burning conditions (flaming, weakly flaming, and smoldering) with five common types of biomass (leaves, branches, corncob, corn stalk, and wheat straw). The total abundances of fine nitrated phenols produced by biomass burning ranged from 2.0 to 99.5 μg m -3 . The compositions of nitrated phenols varied with biomass types and burning conditions. 4-nitrocatechol and methyl nitrocatechols were generally most abundant, accounting for up to 88-95% of total nitrated phenols in flaming burning condition. The emission ratios of nitrated phenols to PM 2.5 increased with the completeness of combustion and ranged from 7 to 45 ppmm and from 239 to 1081 ppmm for smoldering and flaming burning, respectively. The ratios of fine nitrated phenols to organic matter in biomass burning aerosols were comparable to or lower than those in ambient aerosols affected by biomass burning, indicating that secondary formation contributed to ambient levels of fine nitrated phenols. The emission factors of fine nitrated phenols from flaming biomass burning were estimated based on the measured mass fractions and the PM 2.5 emission factors from literature and were approximately 0.75-11.1 mg kg -1 . According to calculations based on corn and wheat production in 31 Chinese provinces in 2013, the total estimated emission of fine nitrated phenols from the burning of corncobs, corn stalks, and wheat straw was 670 t. This work highlights the apparent emission of methyl nitrocatechols from biomass burning and

Factors Affecting University Library Website Design

Directory of Open Access Journals (Sweden)

Yongi-Mi Kim

2011-09-01

Full Text Available Existing studies have extensively explored factors that affect users’ intentions to use university library website resources (ULWR; yet little attention has been given to factors affecting university library website design. This paper investigates factors that affect university library website design and assesses the success of the university library website from both designers’ and users’ perspectives. The findings show that when planning a website, university web designers consider university guidelines, review other websites, and consult with experts and other divisions within the library; however, resources and training for the design process are lacking. While website designers assess their websites as highly successful, user evaluations are somewhat lower. Accordingly, use is low, and users rely heavily on commercial websites. Suggestions for enhancing the usage of ULWR are provided.

Total Protein Content Determination of Microalgal Biomass by Elemental Nitrogen Analysis and a Dedicated Nitrogen-to-Protein Conversion Factor

Energy Technology Data Exchange (ETDEWEB)

Laurens, Lieve M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Olstad-Thompson, Jessica L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Templeton, David W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-02

Accurately determining protein content is important in the valorization of algal biomass in food, feed, and fuel markets, where these values are used for component balance calculations. Conversion of elemental nitrogen to protein is a well-accepted and widely practiced method, but depends on developing an applicable nitrogen-to-protein conversion factor. The methodology reported here covers the quantitative assessment of the total nitrogen content of algal biomass and a description of the methodology that underpins the accurate de novo calculation of a dedicated nitrogen-to-protein conversion factor.

Environmental and biotic controls over aboveground biomass throughout a tropical rainforest

Science.gov (United States)

G.P. Asner; R.F. Hughes; T.A. Varga; D.E. Knapp; T. Kennedy-Bowdoin

2009-01-01

The environmental and biotic factors affecting spatial variation in canopy three-dimensional (3-D) structure and aboveground tree biomass (AGB) are poorly understood in tropical rain forests. We combined field measurements and airborne light detection and ranging (lidar) to quantify 3-D structure and AGB across a 5,016 ha rain forest reserve on the...

Woody biomass policies and location decisions of the woody bioenergy industry in the southern United States

International Nuclear Information System (INIS)

Guo, Zhimei; Hodges, Donald G.; Young, Timothy M.

2013-01-01

Woody biomass for bioenergy production has been included in relatively few renewable energy policies since the 1970s. Recently, however, several states have implemented a variety of new woody biomass policies to spur the establishment of new bioenergy industry. Establishing new woody biomass-based facilities in a specific state is affected by a number of factors such as the strength of these new policy incentives, resource availability, business tax climate, and the available labor force. This study employs a conditional logit model (CLM) to explore the effects of woody biomass policies on the siting decisions of new bioenergy projects relative to some of these other state attributes. The CLM results suggest that state government incentives are significantly related to state success in attracting new plants. The results have substantial implications regarding woody biomass policies and the creation of a new bioenergy industry. -- Highlights: •This study explores the effects of state attributes on the siting decisions of new woody bioenergy projects. •Results suggest that state woody biomass policies are significantly related to state success in attracting new plants. •Other factors related to the siting of woody bioenergy facilities include resource availability, taxes, and wage rate

Measured and modeled humidification factors of fresh smoke particles from biomass burning: role of inorganic constituents

Directory of Open Access Journals (Sweden)

J. L. Hand

2010-07-01

Full Text Available During the 2006 FLAME study (Fire Laboratory at Missoula Experiment, laboratory burns of biomass fuels were performed to investigate the physico-chemical, optical, and hygroscopic properties of fresh biomass smoke. As part of the experiment, two nephelometers simultaneously measured dry and humidified light scattering coefficients (b_sp(dry and b_sp(RH, respectively in order to explore the role of relative humidity (RH on the optical properties of biomass smoke aerosols. Results from burns of several biomass fuels from the west and southeast United States showed large variability in the humidification factor (f(RH=b_sp(RH/b_sp(dry. Values of f(RH at RH=80–85% ranged from 0.99 to 1.81 depending on fuel type. We incorporated measured chemical composition and size distribution data to model the smoke hygroscopic growth to investigate the role of inorganic compounds on water uptake for these aerosols. By assuming only inorganic constituents were hygroscopic, we were able to model the water uptake within experimental uncertainty, suggesting that inorganic species were responsible for most of the hygroscopic growth. In addition, humidification factors at 80–85% RH increased for smoke with increasing inorganic salt to carbon ratios. Particle morphology as observed from scanning electron microscopy revealed that samples of hygroscopic particles contained soot chains either internally or externally mixed with inorganic potassium salts, while samples of weak to non-hygroscopic particles were dominated by soot and organic constituents. This study provides further understanding of the compounds responsible for water uptake by young biomass smoke, and is important for accurately assessing the role of smoke in climate change studies and visibility regulatory efforts.

Forestland owners’ willingness to consider multiple ways of supplying biomass simultaneously: Implications for biofuel incentive policies

International Nuclear Information System (INIS)

Wolde, Bernabas; Lal, Pankaj; Burli, Pralhad

2017-01-01

Because socioeconomic based approaches account for relevant limiting and motivating factors, they provide a more realistic measurement of forestland owners’ willingness to supply biomass for bioenergy production- information useful to policy makers in setting production targets and in designing relevant incentive programs. Although forestland owners can supply biomass using different means, including supplying biomass from existing stands and changing land use to establish feedstock plantation, among others, previous studies mostly focus only on a given way of supplying biomass at a time. This produces incomplete information that adversely affects its use. By presenting survey takers in Virginia and Texas three different ways of supplying biomass at the same time, we determine forestland owners’ willingness to consider multiple ways of supplying biomass simultaneously and identify the factors that predict such behavior, assess overlap in forestland owners across the different ways of supplying biomass, and assess if and how respondents’ forest management plans and sustainability concerns correspond with their supply decision. Our results show a higher and more articulated rate of willingness to supply biomass than reported in previous studies. The results also suggest that opportunities exist for synergizing programs that incentivize disparate ways of supplying biomass. - Highlights: • Forestland owners are more willing to supply biomass than previous estimated. • Forestland owners will consider multiple ways of supplying biomass simultaneously. • Socioeconomics, sustainability concerns, and management plans predict this behavior. • Incentive programs can target multiple means of supplying biomass simultaneously. • Considerable mismatches exist between the suppliers’ preferences and existing policies.

Factors Affecting Tocopherol Concentrations in Soybean Seeds.

Science.gov (United States)

Carrera, Constanza S; Seguin, Philippe

2016-12-21

Soybean seeds contain several health-beneficial compounds, including tocopherols, which are used by the nutraceutical and functional food industries. Soybean tocopherol concentrations are, however, highly variable. Large differences observed in tocopherol concentrations among soybean genotypes together with the relatively simple biosynthetic pathway involving few genes support the feasibility of selecting for high-tocopherol soybean. Tocopherol concentrations are also highly influenced by environmental factors and field management. Temperature during seed filling and soil moisture appear to be the main factors affecting tocopherol concentrations; other factors such as soil fertility and solar radiation also affect concentrations and composition. Field management decisions including seeding date, row spacing, irrigation, and fertilization also affect tocopherols. Knowledge of factors affecting soybean tocopherols is essential to develop management strategies that will lead to the production of seeds with consistent target concentrations that will meet the needs of the nutraceutical and functional food industries.

Factors Affecting Wound Healing

OpenAIRE

Guo, S.; DiPietro, L.A.

2010-01-01

Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutane...

Web-based Factors Affecting Online Purchasing Behaviour

Science.gov (United States)

Ariff, Mohd Shoki Md; Sze Yan, Ng; Zakuan, Norhayati; Zaidi Bahari, Ahamad; Jusoh, Ahmad

2013-06-01

The growing use of internet and online purchasing among young consumers in Malaysia provides a huge prospect in e-commerce market, specifically for B2C segment. In this market, if E-marketers know the web-based factors affecting online buyers' behaviour, and the effect of these factors on behaviour of online consumers, then they can develop their marketing strategies to convert potential customers into active one, while retaining existing online customers. Review of previous studies related to the online purchasing behaviour in B2C market has point out that the conceptualization and empirical validation of the online purchasing behaviour of Information and Communication Technology (ICT) literate users, or ICT professional, in Malaysia has not been clearly addressed. This paper focuses on (i) web-based factors which online buyers (ICT professional) keep in mind while shopping online; and (ii) the effect of web-based factors on online purchasing behaviour. Based on the extensive literature review, a conceptual framework of 24 items of five factors was constructed to determine web-based factors affecting online purchasing behaviour of ICT professional. Analysis of data was performed based on the 310 questionnaires, which were collected using a stratified random sampling method, from ICT undergraduate students in a public university in Malaysia. The Exploratory factor analysis performed showed that five factors affecting online purchase behaviour are Information Quality, Fulfilment/Reliability/Customer Service, Website Design, Quick and Details, and Privacy/Security. The result of Multiple Regression Analysis indicated that Information Quality, Quick and Details, and Privacy/Security affect positively online purchase behaviour. The results provide a usable model for measuring web-based factors affecting buyers' online purchase behaviour in B2C market, as well as for online shopping companies to focus on the factors that will increase customers' online purchase.

Web-based Factors Affecting Online Purchasing Behaviour

International Nuclear Information System (INIS)

Ariff, Mohd Shoki Md; Yan, Ng Sze; Zakuan, Norhayati; Bahari, Ahamad Zaidi; Jusoh, Ahmad

2013-01-01

The growing use of internet and online purchasing among young consumers in Malaysia provides a huge prospect in e-commerce market, specifically for B2C segment. In this market, if E-marketers know the web-based factors affecting online buyers' behaviour, and the effect of these factors on behaviour of online consumers, then they can develop their marketing strategies to convert potential customers into active one, while retaining existing online customers. Review of previous studies related to the online purchasing behaviour in B2C market has point out that the conceptualization and empirical validation of the online purchasing behaviour of Information and Communication Technology (ICT) literate users, or ICT professional, in Malaysia has not been clearly addressed. This paper focuses on (i) web-based factors which online buyers (ICT professional) keep in mind while shopping online; and (ii) the effect of web-based factors on online purchasing behaviour. Based on the extensive literature review, a conceptual framework of 24 items of five factors was constructed to determine web-based factors affecting online purchasing behaviour of ICT professional. Analysis of data was performed based on the 310 questionnaires, which were collected using a stratified random sampling method, from ICT undergraduate students in a public university in Malaysia. The Exploratory factor analysis performed showed that five factors affecting online purchase behaviour are Information Quality, Fulfilment/Reliability/Customer Service, Website Design, Quick and Details, and Privacy/Security. The result of Multiple Regression Analysis indicated that Information Quality, Quick and Details, and Privacy/Security affect positively online purchase behaviour. The results provide a usable model for measuring web-based factors affecting buyers' online purchase behaviour in B2C market, as well as for online shopping companies to focus on the factors that will increase customers' online purchase.

Determining the Factors Affecting Labor Productivity of Nurses

Directory of Open Access Journals (Sweden)

Yurdanur Dikmen

2016-12-01

Results: It was found that the 45.5% of nurses participated in the study were in the 23-53 age group, 79.5% were women, 76.9% married, 41.1% associate degree graduates. 42.3% of nurses' durations of professional experience were 0-5 years, 22.4% of nurses were clinical chief, 69.2% were working as shifts. Participants believe that the factors affecting the labor productivity were respectively organizational factors, ergonomic factors and personal factors. When organizational factors was examined; nurses stated that the lack of working personnel in the section, the low wages and unequal wages for the same work, the long working hours and the system which based on personal relations instead of merit were affecting productivity. The factors affecting labor productivity of nurses were not different according to age, gender, education level and marital status (p>0.05, but different according to mode of operation and years of experience (p<0.05. Conclusion: According to this study, it was found that there are many factors that affect the efficiency of the nurses. The most important factors affecting nurses' efficiency were determined as wage and working conditions. [J Contemp Med 2016; 6(4.000: 334-342

Study on thermochemical liquefaction of biomass feedstocks; Biomass genryo no yuka hanno tokusei ni kansuru kisoteki kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-02-10

Liquefaction is applied to various biomass wastes and unused biomass to study characteristics of the liquefaction in each case. The paper described the system of the conversion and use of biomass into energy, conducted the positioning of the liquefaction, and outlined a history of the liquefaction chemistry and the study. To obtain basic data of characteristics of the liquefaction of various biomass raw materials, the liquefaction was conducted changing operational factors for the purpose of clarifying the product distribution of oil and by-products and oil properties. A comprehensive consideration was made of the liquefaction based on basic data and literature reports on the liquefaction of various biomass. From the above-mentioned studies, it was concluded that the energy can be recovered in a form of oil by applying the liquefaction to various biomass materials. A series of the study clarified effects of various operational factors on characteristics of the liquefaction as well as effects of classification of biomass materials and composition of the materials on characteristics of the liquefaction. 141 refs., 78 figs., 56 tabs.

Environmental Factors Affecting the Whale Shark Aggregation site in the South Central Red Sea

KAUST Repository

Hozumi, Aya

2015-01-01

to questions about the cause of the prey density. A bottom-up process fueled by nutrient input or accumulation from physical advection could create a peak in prey biomass. Wastewater discharged from an aquaculture facility could affect productivity or provide a

[Spatial pattern of forest biomass and its influencing factors in the Great Xing'an Mountains, Heilongjiang Province, China].

Science.gov (United States)

Wang, Xiao-Li; Chang, Yu; Chen, Hong-Wei; Hu, Yuan-Man; Jiao, Lin-Lin; Feng, Yu-Ting; Wu, Wen; Wu, Hai-Feng

2014-04-01

Based on field inventory data and vegetation index EVI (enhanced vegetation index), the spatial pattern of the forest biomass in the Great Xing'an Mountains, Heilongjiang Province was quantitatively analyzed. Using the spatial analysis and statistics tools in ArcGIS software, the impacts of climatic zone, elevation, slope, aspect and vegetation type on the spatial pattern of forest biomass were explored. The results showed that the forest biomass in the Great Xing'an Mountains was 350 Tg and spatially aggregated with great increasing potentials. Forest biomass density in the cold temperate humid zone (64.02 t x hm(-2)) was higher than that in the temperate humid zone (60.26 t x hm(-2)). The biomass density of each vegetation type was in the order of mixed coniferous forest (65.13 t x hm(-2)) > spruce-fir forest (63.92 t x hm(-2)) > Pinus pumila-Larix gmelinii forest (63.79 t x hm(-2)) > Pinus sylvestris var. mongolica forest (61.97 t x hm(-2)) > Larix gmelinii forest (61.40 t x hm(-2)) > deciduous broadleaf forest (58.96 t x hm(-2)). With the increasing elevation and slope, the forest biomass density first decreased and then increased. The forest biomass density in the shady slopes was greater than that in the sunny slopes. The spatial pattern of forest biomass in the Great Xing' an Mountains exhibited a heterogeneous pattern due to the variation of climatic zone, vegetation type and topographical factor. This spatial heterogeneity needs to be accounted when evaluating forest biomass at regional scales.

Root diseases, climate change and biomass productivity

International Nuclear Information System (INIS)

Warren, G.R.; Cruickshank, M.

2004-01-01

Tree growth and yield in eastern boreal spruce fir forests are both greatly affected by root and butt rots. These pests are also prevalent in western coniferous species and boreal-sub-boreal forests. Infections are difficult to detect, but reduced growth, tree mortality, wind throw and scaled butt cull contribute to considerable forest gaps. Harvesting and stand tending practices in second growth stands are creating conditions for increased incidence. Tree stress is one of the major factors affecting the spread of root disease. It is expected that climate change will create abnormal stress conditions that will further compound the incidence of root disease. A comparison was made between natural and managed stands, including harvesting and stand practices such as commercial thinning. Studies of Douglas-fir forests in British Columbia were presented, with results indicating that managed forests contain one third to one half less carbon biomass than unmanaged forests. It was concluded that root diseases must be recognized and taken into account in order to refine and improve biomass estimates, prevent overestimation of wood supply models and avoid potential wood fibre losses. 40 refs., 2 figs.

Estimating Swedish biomass energy supply

International Nuclear Information System (INIS)

Johansson, J.; Lundqvist, U.

1999-01-01

Biomass is suggested to supply an increasing amount of energy in Sweden. There have been several studies estimating the potential supply of biomass energy, including that of the Swedish Energy Commission in 1995. The Energy Commission based its estimates of biomass supply on five other analyses which presented a wide variation in estimated future supply, in large part due to differing assumptions regarding important factors. In this paper, these studies are assessed, and the estimated potential biomass energy supplies are discusses regarding prices, technical progress and energy policy. The supply of logging residues depends on the demand for wood products and is limited by ecological, technological, and economic restrictions. The supply of stemwood from early thinning for energy and of straw from cereal and oil seed production is mainly dependent upon economic considerations. One major factor for the supply of willow and reed canary grass is the size of arable land projected to be not needed for food and fodder production. Future supply of biomass energy depends on energy prices and technical progress, both of which are driven by energy policy priorities. Biomass energy has to compete with other energy sources as well as with alternative uses of biomass such as forest products and food production. Technical progress may decrease the costs of biomass energy and thus increase the competitiveness. Economic instruments, including carbon taxes and subsidies, and allocation of research and development resources, are driven by energy policy goals and can change the competitiveness of biomass energy

Factors affecting endoglucanase production by Trichoderma reesei ...

African Journals Online (AJOL)

Jane

2011-08-22

Aug 22, 2011 ... from the ANOVA analysis have a significant value of Pmodel>F= 0.0008 and R2 .... there are various environmental and nutritional factors ... reported to affect cellulase production from wheat straw ... many factors affecting simultaneously the fermentation ..... and control its stability (Kalra and Sandhu, 1986).

Does species richness affect fine root biomass and production in young forest plantations?

DEFF Research Database (Denmark)

Domisch, Timo; Finér, Leena; Dawud, Seid Muhie

2015-01-01

Tree species diversity has been reported to increase forest ecosystem above-ground biomass and productivity, but little is known about below-ground biomass and production in diverse mixed forests compared to single-species forests. For testing whether species richness increases below-ground biomass...... and production and thus complementarity between forest tree species in young stands, we determined fine root biomass and production of trees and ground vegetation in two experimental plantations representing gradients in tree species richness. Additionally, we measured tree fine root length and determined...... be that these stands were still young, and canopy closure had not always taken place, i.e. a situation where above- or below-ground competition did not yet exist. Another reason could be that the rooting traits of the tree species did not differ sufficiently to support niche differentiation. Our results suggested...

Advanced system demonstration for utilization of biomass as an energy source. Volume I. Scope and design criteria and project summary

Energy Technology Data Exchange (ETDEWEB)

None

1980-10-01

The information in this document is the result of an intensive engineering effort to demonstrate the feasibility of biomass-fueled boilers in cogeneration applications. This design package is based upon a specific site in the State of Maine. However, the design is generic in nature and could serve as a model for other biomass conversion facilities located anywhere biomass is abundant. The project's purpose and summary information are presented: the plant, its concept of operation; and other overall information are described. The capital cost estimate for the plant, and the basis upon which it was obtained are given; a schedule of key milestones and activities required to construct the plant and put it into operation is presented; and the general findings in areas that affect the viability of the project are discussed. The technical design, biomass study, environmental impact, commercialization, and economic factors are addressed. Each major plant area and the equipment and facilities that each includes are discussed in depth. Some overall plant requirements, including noise control, reliability, maintainability, and safety, are detailed. The results of each study relating to alternatives considered for optimizing plant operation parameters and specific system process schemes are briefly presented. All economic factors that affect the feasibility and viability of the biomass project are defined and evaluated.

Working group report: methane emissions from biomass burning

International Nuclear Information System (INIS)

Delmas, R.A.; Ahuja, D.

1993-01-01

Biomass burning is a significant source of atmospheric methane. Like most other sources of methane, it has both natural and anthropogenic causes, although anthropogenic causes now predominate. Most of the estimates of methane emissions from biomass burning in the past have relied on a uniform emission factor for all types of burning. This results in the share of trace gas emissions for different types of burning being the same as the amounts of biomass burned in those types. The Working Group endorsed the extension of an approach followed for Africa by Delmas et al. (1991) to use different emission factors for different types of biomass burning to estimate national emissions of methane. This is really critical as emission factors present important variations. While the focus of discussions of the Working Group was on methane emissions from biomass burning, the Group endorsed the IPCC-OECD methodology of estimating all greenhouse related trace gases from biomass burning. Neither the IPCC-OECD nor the methodology suggested here applies to estimation of trace gas emissions from the processing of biomass to upgraded fuels. They must be estimated separately. The Group also discussed technical options for controlling methane emissions from biomass. 12 refs

Carbon-to-nitrogen ratio affects the biomass composition and the fatty acid profile of heterotrophically grown Chlorella sp. TISTR 8990 for biodiesel production.

Science.gov (United States)

Singhasuwan, Somruethai; Choorit, Wanna; Sirisansaneeyakul, Sarote; Kokkaew, Nakhon; Chisti, Yusuf

2015-12-20

Chlorella sp. TISTR 8990 was cultivated heterotrophically in media with various initial carbon-to-nitrogen ratios (C/N ratio) and at different agitation speeds. The production of the biomass, its total fatty acid content and the composition of the fatty acids were affected by the C/N ratio, but not by agitation speed in the range examined. The biomass production was maximized at a C/N mass ratio of 29:1. At this C/N ratio, the biomass productivity was 0.68gL(-1)d(-1), or nearly 1.6-fold the best attainable productivity in photoautotrophic growth. The biomass yield coefficient on glucose was 0.62gg(-1) during exponential growth. The total fatty acids (TFAs) in the freeze-dried biomass were maximum (459mgg(-1)) at a C/N ratio of 95:1. Lower values of the C/N ratio reduced the fatty acid content of the biomass. The maximum productivity of TFAs (186mgL(-1)d(-1)) occurred at C/N ratios of 63:1 and higher. At these conditions, the fatty acids were mostly of the polyunsaturated type. Allowing the alga to remain in the stationary phase for a prolonged period after N-depletion, reduced the level of monounsaturated fatty acids and the level of polyunsaturated fatty acids increased. Biotin supplementation of the culture medium reduced the biomass productivity relative to biotin-free control, but had no effect on the total fatty acid content of the biomass. Copyright © 2015 Elsevier B.V. All rights reserved.

The relationship between species richness and aboveground biomass in a primary Pinus kesiya forest of Yunnan, southwestern China.

Science.gov (United States)

Li, Shuaifeng; Lang, Xuedong; Liu, Wande; Ou, Guanglong; Xu, Hui; Su, Jianrong

2018-01-01

The relationship between biodiversity and biomass is an essential element of the natural ecosystem functioning. Our research aims at assessing the effects of species richness on the aboveground biomass and the ecological driver of this relationship in a primary Pinus kesiya forest. We sampled 112 plots of the primary P. kesiya forests in Yunnan Province. The general linear model and the structural equation model were used to estimate relative effects of multivariate factors among aboveground biomass, species richness and the other explanatory variables, including climate moisture index, soil nutrient regime and stand age. We found a positive linear regression relationship between the species richness and aboveground biomass using ordinary least squares regressions. The species richness and soil nutrient regime had no direct significant effect on aboveground biomass. However, the climate moisture index and stand age had direct effects on aboveground biomass. The climate moisture index could be a better link to mediate the relationship between species richness and aboveground biomass. The species richness affected aboveground biomass which was mediated by the climate moisture index. Stand age had direct and indirect effects on aboveground biomass through the climate moisture index. Our results revealed that climate moisture index had a positive feedback in the relationship between species richness and aboveground biomass, which played an important role in a link between biodiversity maintenance and ecosystem functioning. Meanwhile, climate moisture index not only affected positively on aboveground biomass, but also indirectly through species richness. The information would be helpful in understanding the biodiversity-aboveground biomass relationship of a primary P. kesiya forest and for forest management.

Experimental measurement of the biomass of Olea europaea L ...

African Journals Online (AJOL)

The C stock evaluation methodology made in this research and the calculation of biomass expansion factor can be considered as the first scientific contribution in estimating productivity, CO2 sequestration, carbon stocks and yield of olive groves. Key words: Biomass, biomass expansion factor, Intergovernmental Panel on ...

Contextual investigation of factors affecting sludge accumulation ...

African Journals Online (AJOL)

Pit latrines in slums areas of Uganda fill up faster than might be expected from some estimates owing to inappropriate use and failure to consider critical factors affecting sludge accumulation rates at the planning, design and construction stages. This study sought to investigate factors affecting filling rates of lined pit latrines ...

Factors Affecting Wound Healing

Science.gov (United States)

Guo, S.; DiPietro, L.A.

2010-01-01

Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds. PMID:20139336

Coupled nutrient removal and biomass production with mixed algal culture: impact of biotic and abiotic factors.

Science.gov (United States)

Su, Yanyan; Mennerich, Artur; Urban, Brigitte

2012-08-01

The influence of biotic (algal inoculum concentration) and abiotic factors (illumination cycle, mixing velocity and nutrient strength) on the treatment efficiency, biomass generation and settleability were investigated with selected mixed algal culture. Dark condition led to poor nutrient removal efficiency. No significant difference in the N, P removal and biomass settleability between continuous and alternating illumination was observed, but a higher biomass generation capability for the continuous illumination was obtained. Different mixing velocity led to similar phosphorus removal efficiencies (above 98%) with different retention times. The reactor with 300 rpm mixing velocity had the best N removal capability. For the low strength wastewater, the N rates were 5.4±0.2, 9.1±0.3 and 10.8±0.3 mg/l/d and P removal rates were 0.57±0.03, 0.56±0.03 and 0.72±0.05 mg/l/d for reactors with the algal inoculum concentration of 0.2, 0.5 and 0.8 g/l, respectively. Low nutrient removal efficiency and poor biomass settleability were obtained for high strength wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

IMPROVING BIOMASS LOGISTICS COST WITHIN AGRONOMIC SUSTAINABILITY CONSTRAINTS AND BIOMASS QUALITY TARGETS

Energy Technology Data Exchange (ETDEWEB)

J. Richard Hess; Kevin L. Kenney; Christopher T. Wright; David J. Muth; William Smith

2012-10-01

Equipment manufacturers have made rapid improvements in biomass harvesting and handling equipment. These improvements have increased transportation and handling efficiencies due to higher biomass densities and reduced losses. Improvements in grinder efficiencies and capacity have reduced biomass grinding costs. Biomass collection efficiencies (the ratio of biomass collected to the amount available in the field) as high as 75% for crop residues and greater than 90% for perennial energy crops have also been demonstrated. However, as collection rates increase, the fraction of entrained soil in the biomass increases, and high biomass residue removal rates can violate agronomic sustainability limits. Advancements in quantifying multi-factor sustainability limits to increase removal rate as guided by sustainable residue removal plans, and mitigating soil contamination through targeted removal rates based on soil type and residue type/fraction is allowing the use of new high efficiency harvesting equipment and methods. As another consideration, single pass harvesting and other technologies that improve harvesting costs cause biomass storage moisture management challenges, which challenges are further perturbed by annual variability in biomass moisture content. Monitoring, sampling, simulation, and analysis provide basis for moisture, time, and quality relationships in storage, which has allowed the development of moisture tolerant storage systems and best management processes that combine moisture content and time to accommodate baled storage of wet material based upon “shelf-life.” The key to improving biomass supply logistics costs has been developing the associated agronomic sustainability and biomass quality technologies and processes that allow the implementation of equipment engineering solutions.

Biomass energy, forests and global warming

International Nuclear Information System (INIS)

Rosillo-Calle, Frank; Hall, D.O.

1992-01-01

Biomass in all its forms currently provides about 14% of the world's energy, equivalent to 25 million bbl oil/day; in developing countries where it is the major energy source, biomass supplies 35% of total energy use. Although biomass energy use affects the flux of carbon to the atmosphere, the main carbon emission problem is caused by fossil fuels and land clearance for agriculture. Biomass fuels make no net contribution to atmospheric CO 2 if used sustainably. A major global revegetation and reforestation effort is a possible strategy to reduce CO 2 emissions and to slow the pace of climatic change. However, a more attractive alternative strategy might be to substitute fossil fuels, especially coal, with biomass grown specifically for this purpose producing modern fuels such as electricity, liquids and gases. This paper examines biomass energy use, devegetation, biomass burning, the implications for global warming and the ability of biomass to sequester CO 2 and substitute for fossil fuels. It also discusses some socioeconomic and political issues. (author)

Biomass as a fuel: Advantages, limitations and possibilities

International Nuclear Information System (INIS)

McBurney, B.

1997-01-01

This presentation briefly outlines major issues related to the use of biomass fuels. Advantages and disadvantages of biomass fuels are identified, as well as major factors that may facilitate greater use of biomass fuels. Highlights of the US DOE Biomass Power Program, program activities, and demonstration projects are presented. Some statistical and economic data are provided, including biomass fueled electric capacity, biomass energy consumption by sector, and fuel cost savings and greenhouse gas emissions reductions for four biomass co-fired units

Identification of factors affecting individual industries

Directory of Open Access Journals (Sweden)

Maryam Sadat Mirzadeh

2017-10-01

Full Text Available High knowledge and technology are rapidly becoming a competitive advantage in today’s world. Individual industries are considered one of the key sectors in the country’s industry. Ranking the factors that affect these industries makes us more familiar with their effectiveness and helps us take actions to improve such factors in knowledge-based companies. Consequently, based on previous research studies on Individual Industries, field observations, and a questionnaire prepared by the researchers, the current study explores and classifies the factors affecting the establishment of these industries. Regarding its purpose, this is an applied research, and regarding data collection, it is a descriptive survey. Using purposive sampling, 60 questionnaires were collected and effective factors were classified applying the SPSS software and the TOPSIS technique. This study suggests that content factors are ranked first place, while contextual and structural factors are ranked second and third, respectively. Therefore, executives and managers in single industries are recommended to strengthen joint enterprise norms and dominant values and beliefs in knowledge-based companies in order to help the growth and development of single industries.

Factors affecting farm diversification in rice-wheat

International Nuclear Information System (INIS)

Ashfaq, M.; Hassan, S.; Naseer, M.Z.; Baig, I.A.; Asma, J.

2008-01-01

The risk in agriculture sector is due to various factors like weather and market conditions, particularly the demand of the commodities. This uncertainty can result in variable returns (farm income) to the decisions that farmers make in a particular season. Diversification is a frequently used risk management strategy that involves participation in more than one activity. It has the added advantage of mitigating price risk as well as fluctuations in outputs. The main purpose of this paper was to determine the factors affecting crop diversification. For determining the effect of different factors on diversification a multiple regression model was used. The values of Entropy index computed for measuring horizontal diversification were taken as dependent variable and different factors affecting diversification were taken as independent variables. The results showed that the main factors affecting diversification were size of land holding, age of respondent, education level of respondent, farming experience of respondent, off farm income of respondent, distance of farm from main road, distance of farm from main market and farm machinery. (author)

Recycling slaughterhouse waste into fertilizer: how do pyrolysis temperature and biomass additions affect phosphorus availability and chemistry?

Science.gov (United States)

Zwetsloot, Marie J; Lehmann, Johannes; Solomon, Dawit

2015-01-01

Pyrolysis of slaughterhouse waste could promote more sustainable phosphorus (P) usage through the development of alternative P fertilizers. This study investigated how pyrolysis temperature (220, 350, 550 and 750 °C), rendering before pyrolysis, and wood or corn biomass additions affect P chemistry in bone char, plant availability, and its potential as P fertilizer. Linear combination fitting of synchrotron-based X-ray absorption near edge structure spectra demonstrated that higher pyrolysis temperatures decreased the fit with organic P references, but increased the fit with a hydroxyapatite (HA) reference, used as an indicator of high calcium phosphate (CaP) crystallinity. The fit to the HA reference increased from 0% to 69% in bone with meat residue and from 20% to 95% in rendered bone. Biomass additions to the bone with meat residue reduced the fit to the HA reference by 83% for wood and 95% for corn, and additions to rendered bone by 37% for wood. No detectable aromatic P forms were generated by pyrolysis. High CaP crystallinity was correlated with low water-extractable P, but high formic acid-extractable P indicative of high plant availability. Bone char supplied available P which was only 24% lower than Triple Superphosphate fertilizer and two- to five-fold higher than rock phosphate. Pyrolysis temperature and biomass additions can be used to design P fertilizer characteristics of bone char through changing CaP crystallinity that optimize P availability to plants. © 2014 Society of Chemical Industry.

Potential impact of mangrove clearance on biomass and biomass size spectra of nematode along the Sudanese Red Sea coast.

Science.gov (United States)

Sabeel, Rasha Adam Osman; Vanreusel, Ann

2015-02-01

The potential effect of mangrove clearance on nematode assemblage biomass, biomass size spectra (NBSS) and abundance/biomass curves (ABC) was investigated in three sites representing a varying degree of mangrove clearance as well as in three stations established at each sites representing high-, mid- and low-water levels. Results revealed significant differences in sediment and nematode characteristics between the three sites. Although both the cleared and the intact mangrove had comparable biomass values, clear differences in biomass size spectra and abundance biomass curves were observed. The results suggested that the variation in the silt fraction and the food quality positively affected the total biomass. Mangrove clearance has caused a shift from a unimodal to a bimodal biomass size spectrum at all water levels, owing to an increase in smaller-bodied opportunistic non-selective deposit feeding nematodes. The ABC further confirmed the effect of clearance by classifying the cleared mangrove as moderately to grossly disturbed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Romania biomass energy. Country study

Energy Technology Data Exchange (ETDEWEB)

Burnham, M; Easterly, J L; Mark, P E; Keller, A [DynCorp, Alexandria, VA (United States)

1995-12-01

The present report was prepared under contract to UNIDO to conduct a case study of biomass energy use and potential in Romania. The purpose of the case study is to provide a specific example of biomass energy issues and potential in the context of the economic transition under way in eastern Europe. The transition of Romania to a market economy is proceeding at a somewhat slower pace than in other countries of eastern Europe. Unfortunately, the former regime forced the use of biomass energy with inadequate technology and infrastructure, particularly in rural areas. The resulting poor performance thus severely damaged the reputation of biomass energy in Romania as a viable, reliable resource. Today, efforts to rejuvenate biomass energy and tap into its multiple benefits are proving challenging. Several sound biomass energy development strategies were identified through the case study, on the basis of estimates of availability and current use of biomass resources; suggestions for enhancing potential biomass energy resources; an overview of appropriate conversion technologies and markets for biomass in Romania; and estimates of the economic and environmental impacts of the utilization of biomass energy. Finally, optimal strategies for near-, medium- and long-term biomass energy development, as well as observations and recommendations concerning policy, legislative and institutional issues affecting the development of biomass energy in Romania are presented. The most promising near-term biomass energy options include the use of biomass in district heating systems; cofiring of biomass in existing coal-fired power plants or combined heat and power plants; and using co-generation systems in thriving industries to optimize the efficient use of biomass resources. Mid-term and long-term opportunities include improving the efficiency of wood stoves used for cooking and heating in rural areas; repairing the reputation of biogasification to take advantage of livestock wastes

Romania biomass energy. Country study

International Nuclear Information System (INIS)

Burnham, M.; Easterly, J.L.; Mark, P.E.; Keller, A.

1995-01-01

The present report was prepared under contract to UNIDO to conduct a case study of biomass energy use and potential in Romania. The purpose of the case study is to provide a specific example of biomass energy issues and potential in the context of the economic transition under way in eastern Europe. The transition of Romania to a market economy is proceeding at a somewhat slower pace than in other countries of eastern Europe. Unfortunately, the former regime forced the use of biomass energy with inadequate technology and infrastructure, particularly in rural areas. The resulting poor performance thus severely damaged the reputation of biomass energy in Romania as a viable, reliable resource. Today, efforts to rejuvenate biomass energy and tap into its multiple benefits are proving challenging. Several sound biomass energy development strategies were identified through the case study, on the basis of estimates of availability and current use of biomass resources; suggestions for enhancing potential biomass energy resources; an overview of appropriate conversion technologies and markets for biomass in Romania; and estimates of the economic and environmental impacts of the utilization of biomass energy. Finally, optimal strategies for near-, medium- and long-term biomass energy development, as well as observations and recommendations concerning policy, legislative and institutional issues affecting the development of biomass energy in Romania are presented. The most promising near-term biomass energy options include the use of biomass in district heating systems; cofiring of biomass in existing coal-fired power plants or combined heat and power plants; and using co-generation systems in thriving industries to optimize the efficient use of biomass resources. Mid-term and long-term opportunities include improving the efficiency of wood stoves used for cooking and heating in rural areas; repairing the reputation of biogasification to take advantage of livestock wastes

Emission of Metals from Pelletized and Uncompressed Biomass Fuels Combustion in Rural Household Stoves in China

Science.gov (United States)

Zhang, Wei; Tong, Yindong; Wang, Huanhuan; Chen, Long; Ou, Langbo; Wang, Xuejun; Liu, Guohua; Zhu, Yan

2014-07-01

Effort of reducing CO2 emissions in developing countries may require an increasing utilization of biomass fuels. Biomass pellets seem well-suited for residential biomass markets. However, there is limited quantitative information on pollutant emissions from biomass pellets burning, especially those measured in real applications. In this study, biomass pellets and raw biomass fuels were burned in a pellet burner and a conventional stove respectively, in rural households, and metal emissions were determined. Results showed that the emission factors (EFs) ranged 3.20-5.57 (Pb), 5.20-7.58 (Cu), 0.11-0.23 (Cd), 12.67-39.00 (As), 0.59-1.31 mg/kg (Ni) for pellets, and 0.73-1.34 (Pb), 0.92-4.48 (Cu), 0.08-0.14 (Cd), 7.29-13.22 (As), 0.28-0.62 (Ni) mg/kg for raw biomass. For unit energy delivered to cooking vessels, the EFs ranged 0.42-0.77 (Pb), 0.79-1.16 (Cu), 0.01-0.03 (Cd), 1.93-5.09 (As), 0.08-0.19 mg/MJ (Ni) for pellets, and 0.30-0.56 (Pb), 0.41-1.86 (Cu), 0.04-0.06 (Cd), 3.25-5.49 (As), 0.12-0.26 (Ni) mg/MJ for raw biomass. This study found that moisture, volatile matter and modified combustion efficiency were the important factors affecting metal emissions. Comparisons of the mass-based and task-based EFs found that biomass pellets produced higher metal emissions than the same amount of raw biomass. However, metal emissions from pellets were not higher in terms of unit energy delivered.

Corn Stover Availability for Biomass Conversion: Situation Analysis

International Nuclear Information System (INIS)

Hess, J. Richard; Kenney, Kevin L.; Wright, Christopher T.; Perlack, Robert; Turhollow, Anthony

2009-01-01

As biorefining conversion technologies become commercial, feedstock availability, supply system logistics, and biomass material attributes are emerging as major barriers to the availability of corn stover for biorefining. While systems do exist to supply corn stover as feedstock to biorefining facilities, stover material attributes affecting physical deconstruction, such as densification and post-harvest material stability, challenge the cost-effectiveness of present-day feedstock logistics systems. In addition, the material characteristics of corn stover create barriers with any supply system design in terms of equipment capacity/efficiency, dry matter loss, and capital use efficiency. However, this study of a large, square-bale corn stover feedstock supply system concludes that (1) where other agronomic factors are not limiting, corn stover can be accessed and supplied to a biorefinery using existing bale-based technologies, (2) technologies and new supply system designs are necessary to overcome biomass bulk density and moisture material property challenges, and (3) major opportunities to improve conventional-bale biomass feedstock supply systems include improvements in equipment efficiency and capacity and reducing biomass losses in harvesting and collection and storage. Finally, the backbone of an effective stover supply system design is the optimization of intended and minimization of unintended material property changes as the corn stover passes through the individual supply system processes from the field to the biorefinery conversion processes

Simulation and assessment of agricultural biomass supply chain systems

Directory of Open Access Journals (Sweden)

D. Pavlou

2017-05-01

Full Text Available Agricultural biomass supply chain consists of a number of interacted sequential operations affected by various variables, such as weather conditions, machinery systems, and biomass features. These facts make the process of biomass supply chain as a complex system that requires computational tools, e.g. simulation and mathematical models, for their assessment and analysis. A biomass supply chain simulation model developed on the ExtendSim 8 simulation environment is presented in this paper. A number of sequential operations are applied in order biomass to be mowed, harvested, and transported to a biorefinery facility. Different operational scenarios regarding the travel distance between field and biorefinery facility, number of machines, and capacity of machines are analyzed showing how different parameters affect the processes within biomass supply chain in terms of time and cost. The results shown that parameters such as area of the field, travel distance, number of available machines, capacity of the machines, etc. should be taken into account in order a less time and/ or cost consuming machinery combination to be selected.

Review Article Exposure to biomass smoke as a risk factor for ...

African Journals Online (AJOL)

Biomass smoke exposure and upper GI cancers. © 2017 The College of .... with age- and sex-matched controls, revealed a significant association with biomass ..... Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2016 Mar ...

Age Learning Factors Affecting Pilot Education.

Science.gov (United States)

Torbert, Brison

This document, intended for pilot education and flight safety specialists, consists chiefly of a review of the literature on physiological factors that affect pilot education and an examination of environmental factors that should be scrutinized in order to improve the effectiveness of aviation learning facilities. The physiological factors…

Perceived Factors Affecting Performance Of Extension Workers In ...

African Journals Online (AJOL)

The study focused on perceived factors affecting performance of extension workers in Imo State, Nigeria. Data for the study was collected from 83 Extension agents from the Imo State Agricultural Development Programme (ADP). Results of the study revealed that the organizational factors that affect performance are ...

Sustainable Development Strategies of Biomass Energy in Beijing

Science.gov (United States)

Zhang, H. Z.; Huang, B. R.

2017-10-01

The development of biomass energy industry can effectively improve the rural environment and alleviate the shortage of living energy in rural areas, especially in mountain areas. In order to make clear the current situation of biomass energy industry development in Beijing, this paper analyzed the status of biomass resources and biomass energy utilization and discussed the factors hindering the development of biomass energy industry in Beijing. Based on the analysis, suggestions for promoting sustainable development of Biomass Energy Industry in Beijing are put forward.

Sustainability of biomass for cofiring

Energy Technology Data Exchange (ETDEWEB)

NONE

2014-02-01

There are many items to include when considering the sustainability of biomass for cofiring, and some of them are hard to quantify. The focus of this report is on the greenhouse gas emission aspects of sustainability. The reduction of greenhouse gas emissions achieved by substituting biomass for coal depends on a number of factors such as the nature of the fossil fuel reference system, the source of the biomass, and how it is produced. Relevant issues in biomass production include the energy balance, the greenhouse gas balance, land use change, non-CO2 greenhouse gas emission from soils, changes to soil organic carbon, and the timing of emissions and removal of CO2 which relates to the scale of biomass production. Certification of sustainable biomass is slow to emerge at the national and international level, so various organisations are developing and using their own standards for sustainable production. The EU does not yet have sustainability standards for solid biomass, but the UK and Belgium have developed their own.

ANALYSIS OF THE FACTORS AFFECTING THE AVERAGE

Directory of Open Access Journals (Sweden)

Carmen BOGHEAN

2013-12-01

Full Text Available Productivity in agriculture most relevantly and concisely expresses the economic efficiency of using the factors of production. Labour productivity is affected by a considerable number of variables (including the relationship system and interdependence between factors, which differ in each economic sector and influence it, giving rise to a series of technical, economic and organizational idiosyncrasies. The purpose of this paper is to analyse the underlying factors of the average work productivity in agriculture, forestry and fishing. The analysis will take into account the data concerning the economically active population and the gross added value in agriculture, forestry and fishing in Romania during 2008-2011. The distribution of the average work productivity per factors affecting it is conducted by means of the u-substitution method.

Environmental Factors Affecting Preschoolers' Motor Development

Science.gov (United States)

Venetsanou, Fotini; Kambas, Antonis

2010-01-01

The process of development occurs according to the pattern established by the genetic potential and also by the influence of environmental factors. The aim of the present study was to focus on the main environmental factors affecting motor development. The review of the literature revealed that family features, such as socioeconomic status,…

Electricity from biomass in the European Union - with or without biomass import

DEFF Research Database (Denmark)

Skytte, K.; Meibom, P.; Henriksen, T.C.

2006-01-01

The European Union has set up indicative targets for its 15 Member States to supply 22.1% of their total electricity consumption using renewable energy resources by 2010. This paper compares two ways to achieve target compliance-either with import of biomass from countries outside the EU or without...... is that increased imports of low-cost biomass will significantly reduce the cost of target compliance, but would hamper the use of energy crops and further development of wind power within the EU. Despite this, increased importation of biomass can be the cost-reducing factor making the target realisable, which...... would justify promotion of such trade. (c) 2005 Elsevier Ltd. All rights reserved....

Analysing biomass torrefaction supply chain costs.

Science.gov (United States)

Svanberg, Martin; Olofsson, Ingemar; Flodén, Jonas; Nordin, Anders

2013-08-01

The objective of the present work was to develop a techno-economic system model to evaluate how logistics and production parameters affect the torrefaction supply chain costs under Swedish conditions. The model consists of four sub-models: (1) supply system, (2) a complete energy and mass balance of drying, torrefaction and densification, (3) investment and operating costs of a green field, stand-alone torrefaction pellet plant, and (4) distribution system to the gate of an end user. The results show that the torrefaction supply chain reaps significant economies of scale up to a plant size of about 150-200 kiloton dry substance per year (ktonDS/year), for which the total supply chain costs accounts to 31.8 euro per megawatt hour based on lower heating value (€/MWhLHV). Important parameters affecting total cost are amount of available biomass, biomass premium, logistics equipment, biomass moisture content, drying technology, torrefaction mass yield and torrefaction plant capital expenditures (CAPEX). Copyright © 2013 Elsevier Ltd. All rights reserved.

Household biomass energy choice and its policy implications on improving rural livelihoods in Sichuan, China

International Nuclear Information System (INIS)

Chen, Qiu; Yang, Haoran; Liu, Tianbiao; Zhang, Lin

2016-01-01

It is widely known that a switch from traditional biomass energy to modern clean, safe and efficient energy could improve local rural livelihoods by enhancing the access to ‘high quality’ energy and reducing the negative impacts of traditional biomass energy on health, environment and living standards. Hence, in this paper, we used alternative-specific conditional logit model (ASCLM) to examine the rural household energy choice behaviors in Sichuan Province of China from the perspective of revealed and stated preferences. The results show that the fuel switching in our study region is not a simple unidirectional process from traditional biomass energy to modern fuels as incomes improve. Household energy choice behaviors could be not only affected by energy-specific characteristics such as fuel price, smoky level and safety risk, but also influenced by household-specific factors such as income level, age and educational level of the decision maker, household demographic structure, number of people frequently eating at home, distance to the nearest biomass collecting spot and household location, suggesting that government should attach more importance to simultaneously improve energy quality, control energy price and enhance household socio-economic status. - Highlights: •McFadden's choice model was applied to analyze household energy choice in Sichuan. •We examined household revealed and stated preferences for different fuels. •Household fuel switching is not a simple or unidirectional process. •Households prefer to use fuel with lower cost, higher safety and lower indoor pollution. •Household fuel choice is affected by interactions among multiple factors.

Fouling control in biomass boilers

Energy Technology Data Exchange (ETDEWEB)

Romeo, Luis M.; Gareta, Raquel [Centro de Investigacion de Recursos y Consumos Energeticos (CIRCE), Universidad de Zaragoza, Centro Politecnico Superior, Maria de Luna, 3, 50018 Zaragoza (Spain)

2009-05-15

One of the important challenges for biomass combustion in industrial applications is the fouling tendency and how it affects to the boiler performance. The classical approach for this question is to activate sootblowing cycles with different strategies to clean the boiler (one per shift, one each six hours..). Nevertheless, it has been often reported no effect on boiler fouling or an excessive steam consumption for sootblowing. This paper illustrates the methodology and the application to select the adequate time for activating sootblowing in an industrial biomass boiler. The outcome is a control strategy developed with artificial intelligence (Neural Network and Fuzzy Logic Expert System) for optimizing the biomass boiler cleaning and maximizing heat transfer along the time. Results from an optimize sootblowing schedule show savings up to 12 GWh/year in the case-study biomass boiler. Extra steam generation produces an average increase of turbine power output of 3.5%. (author)

Biomass Burning Observation Project (BBOP) Final Campaign Report

Energy Technology Data Exchange (ETDEWEB)

Kleinman, LI [Brookhaven National Lab. (BNL), Upton, NY (United States); Sedlacek, A. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2016-01-01

The Biomass Burning Observation Project (BBOP) was conducted to obtain a better understanding of how aerosols generated from biomass fires affect the atmosphere and climate. It is estimated that 40% of carbonaceous aerosol produced originates from biomass burning—enough to affect regional and global climate. Several biomass-burning studies have focused on tropical climates; however, few campaigns have been conducted within the United States, where millions of acres are burned each year, trending to higher values and greater climate impacts because of droughts in the West. Using the Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF), the BBOP deployed the Gulfstream-1 (G-1) aircraft over smoke plumes from active wildfire and agricultural burns to help identify the impact of these events and how impacts evolve with time. BBOP was one of very few studies that targeted the near-field time evolution of aerosols and aimed to obtain a process-level understanding of the large changes that occur within a few hours of atmospheric processing.

The relationship between affective factors and the academic ...

African Journals Online (AJOL)

The purpose of this study is to investigate the relationship between affective factors and the academic achievement of students at the University of Venda. To this end, self-concept, motivation and attitude are the affective factors selected for the study. The general aim of the study is to determine the role of self-concept, ...

Explaining biomass growth of tropical canopy trees: the importance of sapwood

OpenAIRE

Sande, van der, M.T.; Zuidema, P.A.; Sterck, F.J.

2015-01-01

Tropical forests are important in worldwide carbon (C) storage and sequestration. C sequestration of these forests may especially be determined by the growth of canopy trees. However, the factors driving variation in growth among such large individuals remain largely unclear. We evaluate how crown traits [total leaf area, specific leaf area and leaf nitrogen (N) concentration] and stem traits [sapwood area (SA) and sapwood N concentration] measured for individual trees affect absolute biomass...

Explaining biomass growth of tropical canopy trees: the importance of sapwood.

Science.gov (United States)

van der Sande, Masha T; Zuidema, Pieter A; Sterck, Frank

2015-04-01

Tropical forests are important in worldwide carbon (C) storage and sequestration. C sequestration of these forests may especially be determined by the growth of canopy trees. However, the factors driving variation in growth among such large individuals remain largely unclear. We evaluate how crown traits [total leaf area, specific leaf area and leaf nitrogen (N) concentration] and stem traits [sapwood area (SA) and sapwood N concentration] measured for individual trees affect absolute biomass growth for 43 tropical canopy trees belonging to four species, in a moist forest in Bolivia. Biomass growth varied strongly among trees, between 17.3 and 367.3 kg year(-1), with an average of 105.4 kg year(-1). We found that variation in biomass growth was chiefly explained by a positive effect of SA, and not by tree size or other traits examined. SA itself was positively associated with sapwood growth, sapwood lifespan and basal area. We speculate that SA positively affects the growth of individual trees mainly by increasing water storage, thus securing water supply to the crown. These positive roles of sapwood on growth apparently offset the increased respiration costs incurred by more sapwood. This is one of the first individual-based studies to show that variation in sapwood traits-and not crown traits-explains variation in growth among tropical canopy trees. Accurate predictions of C dynamics in tropical forests require similar studies on biomass growth of individual trees as well as studies evaluating the dual effect of sapwood (water provision vs. respiratory costs) on tropical tree growth.

High-throughput microplate technique for enzymatic hydrolysis of lignocellulosic biomass.

Science.gov (United States)

Chundawat, Shishir P S; Balan, Venkatesh; Dale, Bruce E

2008-04-15

Several factors will influence the viability of a biochemical platform for manufacturing lignocellulosic based fuels and chemicals, for example, genetically engineering energy crops, reducing pre-treatment severity, and minimizing enzyme loading. Past research on biomass conversion has focused largely on acid based pre-treatment technologies that fractionate lignin and hemicellulose from cellulose. However, for alkaline based (e.g., AFEX) and other lower severity pre-treatments it becomes critical to co-hydrolyze cellulose and hemicellulose using an optimized enzyme cocktail. Lignocellulosics are appropriate substrates to assess hydrolytic activity of enzyme mixtures compared to conventional unrealistic substrates (e.g., filter paper, chromogenic, and fluorigenic compounds) for studying synergistic hydrolysis. However, there are few, if any, high-throughput lignocellulosic digestibility analytical platforms for optimizing biomass conversion. The 96-well Biomass Conversion Research Lab (BCRL) microplate method is a high-throughput assay to study digestibility of lignocellulosic biomass as a function of biomass composition, pre-treatment severity, and enzyme composition. The most suitable method for delivering milled biomass to the microplate was through multi-pipetting slurry suspensions. A rapid bio-enzymatic, spectrophotometric assay was used to determine fermentable sugars. The entire procedure was automated using a robotic pipetting workstation. Several parameters that affect hydrolysis in the microplate were studied and optimized (i.e., particle size reduction, slurry solids concentration, glucan loading, mass transfer issues, and time period for hydrolysis). The microplate method was optimized for crystalline cellulose (Avicel) and ammonia fiber expansion (AFEX) pre-treated corn stover. Copyright 2008 Wiley Periodicals, Inc.

Improving satellite retrievals of NO2 in biomass burning regions

Science.gov (United States)

Bousserez, N.; Martin, R. V.; Lamsal, L. N.; Mao, J.; Cohen, R. C.; Anderson, B. E.

2010-12-01

The quality of space-based nitrogen dioxide (NO2) retrievals from solar backscatter depends on a priori knowledge of the NO2 profile shape as well as the effects of atmospheric scattering. These effects are characterized by the air mass factor (AMF) calculation. Calculation of the AMF combines a radiative transfer calculation together with a priori information about aerosols and about NO2 profiles (shape factors), which are usually taken from a chemical transport model. In this work we assess the impact of biomass burning emissions on the AMF using the LIDORT radiative transfer model and a GEOS-Chem simulation based on a daily fire emissions inventory (FLAMBE). We evaluate the GEOS-Chem aerosol optical properties and NO2 shape factors using in situ data from the ARCTAS summer 2008 (North America) and DABEX winter 2006 (western Africa) experiments. Sensitivity studies are conducted to assess the impact of biomass burning on the aerosols and the NO2 shape factors used in the AMF calculation. The mean aerosol correction over boreal fires is negligible (+3%), in contrast with a large reduction (-18%) over African savanna fires. The change in sign and magnitude over boreal forest and savanna fires appears to be driven by the shielding effects that arise from the greater biomass burning aerosol optical thickness (AOT) above the African biomass burning NO2. In agreement with previous work, the single scattering albedo (SSA) also affects the aerosol correction. We further investigated the effect of clouds on the aerosol correction. For a fixed AOT, the aerosol correction can increase from 20% to 50% when cloud fraction increases from 0 to 30%. Over both boreal and savanna fires, the greatest impact on the AMF is from the fire-induced change in the NO2 profile (shape factor correction), that decreases the AMF by 38% over the boreal fires and by 62% of the savanna fires. Combining the aerosol and shape factor corrections together results in small differences compared to the

Numerical simulation of a biomass fired grate boiler

DEFF Research Database (Denmark)

Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

2006-01-01

Computational fluid dynamic (CFD) analysis of the thermal flow in the combustion furnace of a biomass-fired grate boiler provides crucial insight into the boiler's performance. Quite a few factors play important roles in a general CFD analysis, such as grid, models, discretization scheme and so on....... For a grate boiler, the modeling the interaction of the fuel bed and the gas phase above the bed is also essential. Much effort can be found in literature on developing bed models whose results are introduced into CFD simulations of freeboard as inlet conditions. This paper presents a CFD analysis...... of the largest biomass-fired grate boiler in Denmark. The focus of this paper is to study how significantly an accurate bed model can affect overall CFD results, i.e., how necessarily it is to develop an accurate bed model in terms of the reliability of CFD results. The ultimate purpose of the study is to obtain...

Nutritional Factors Affecting Adult Neurogenesis and Cognitive Function.

Science.gov (United States)

Poulose, Shibu M; Miller, Marshall G; Scott, Tammy; Shukitt-Hale, Barbara

2017-11-01

Adult neurogenesis, a complex process by which stem cells in the hippocampal brain region differentiate and proliferate into new neurons and other resident brain cells, is known to be affected by many intrinsic and extrinsic factors, including diet. Neurogenesis plays a critical role in neural plasticity, brain homeostasis, and maintenance in the central nervous system and is a crucial factor in preserving the cognitive function and repair of damaged brain cells affected by aging and brain disorders. Intrinsic factors such as aging, neuroinflammation, oxidative stress, and brain injury, as well as lifestyle factors such as high-fat and high-sugar diets and alcohol and opioid addiction, negatively affect adult neurogenesis. Conversely, many dietary components such as curcumin, resveratrol, blueberry polyphenols, sulforaphane, salvionic acid, polyunsaturated fatty acids (PUFAs), and diets enriched with polyphenols and PUFAs, as well as caloric restriction, physical exercise, and learning, have been shown to induce neurogenesis in adult brains. Although many of the underlying mechanisms by which nutrients and dietary factors affect adult neurogenesis have yet to be determined, nutritional approaches provide promising prospects to stimulate adult neurogenesis and combat neurodegenerative diseases and cognitive decline. In this review, we summarize the evidence supporting the role of nutritional factors in modifying adult neurogenesis and their potential to preserve cognitive function during aging. © 2017 American Society for Nutrition.

Energy from biomass: An overview

International Nuclear Information System (INIS)

Van der Toorn, L.J.; Elliott, T.P.

1992-01-01

Attention is paid to the effect of the use of energy from biomass on the greenhouse effect. An overview is given of the aspects of forest plantation, carbon dioxide fixation and energy from biomass, in particular with regard to the potential impact of the use of biomass energy on the speed of accumulation of carbon in the atmosphere. A simple model of the carbon cycle to illustrate the geochemical, biological and antropogenic characteristics of the cycle is presented and briefly discussed. Biomass, which is appropriate for energy applications, can be subdivided into three categories: polysaccharides, vegetable oils, and lignocellulosis. The costs for the latter are discussed. Three important options to use biomass as a commercial energy source are solid fuels, liquid fuels, and power generation. For each option the value of energy (on a large-scale level) is compared to the costs of several types of biomass. Recent evaluation of new techniques show that small biomass conversion plants can realize an electricity efficiency of 40%, with capitalized costs far below comparable conventional biomass conversion plants. One of the policy instruments to stimulate the use of biomass as an energy source is the carbon levy, in which the assumed external costs to reduce carbon dioxide emission are expressed. Political and administrative feasibility are important factors in the decision making with regard to carbon storage and energy plantations. 6 figs

Factors Affecting Green Residential Building Development: Social Network Analysis

Directory of Open Access Journals (Sweden)

Xiaodong Yang

2018-05-01

Full Text Available Green residential buildings (GRBs are one of the effective practices of energy saving and emission reduction in the construction industry. However, many real estate developers in China are less willing to develop GRBs, because of the factors affecting green residential building development (GRBD. In order to promote the sustainable development of GRBs in China, this paper, based on the perspective of real estate developers, identifies the influential and critical factors affecting GRBD, using the method of social network analysis (SNA. Firstly, 14 factors affecting GRBD are determined from 64 preliminary factors of three main elements, and the framework is established. Secondly, the relationships between the 14 factors are analyzed by SNA. Finally, four critical factors for GRBD, which are on the local economy development level, development strategy and innovation orientation, developer’s acknowledgement and positioning for GRBD, and experience and ability for GRBD, are identified by the social network centrality test. The findings illustrate the key issues that affect the development of GRBs, and provide references for policy making by the government and strategy formulation by real estate developers.

Regulation of bacterioplankton density and biomass in tropical shallow coastal lagoons

Directory of Open Access Journals (Sweden)

Fabiana MacCord

Full Text Available AIM: Estimating bacterioplankton density and biomass and their regulating factors is important in order to evaluate aquatic systems' carrying capacity, regarding bacterial growth and the stock of matter in the bacterial community, which can be consumed by higher trophic levels. We aim to evaluate the limnological factors which regulate - in space and time - the bacterioplankton dynamics (abundance and biomass in five tropical coastal lagoons in the state of Rio de Janeiro, Brazil. METHOD: The current study was carried out at the following lagoons: Imboassica, Cabiúnas, Comprida, Carapebus and Garças. They differ in morphology and in their main limnological factors. The limnological variables as well as bacterioplankton abundance and biomass were monthly sampled for 14 months. Model selection analyses were performed in order to evaluate the main variables regulating the bacterioplankton's dynamics in these lagoons. RESULT: The salt concentration and the "space" factor (i.e. different lagoons explained great part of the bacterial density and biomass variance in the studied tropical coastal lagoons. When the lagoons were analyzed separately, salinity still explained great part of the variation of bacterial density and biomass in the Imboassica and Garças lagoons. On the other hand, phosphorus concentration was the main factor explaining the variance of bacterial density and biomass in the distrophic Cabiúnas, Comprida and Carapebus lagoons. There was a strong correlation between bacterial density and biomass (r² = 0.70, p < 0.05, indicating that bacterial biomass variations are highly dependent on bacterial density variations. CONCLUSION: (i Different limnological variables regulate the bacterial density and biomass in the studied coastal lagoons, (ii salt and phosphorus concentrations greatly explained the variation of bacterial density and biomass in the saline and distrophic lagoons, respectively, and (iii N-nitrate and chlorophyll

Factors affecting dignity of patients with multiple sclerosis.

Science.gov (United States)

Sharifi, Simin; Borhani, Fariba; Abbaszadeh, Abbas

2016-12-01

MS is one of the most common chronic diseases of the nervous system. Apart from disease progression, other complications such as unemployment, separation and divorce could potentially threat patients' dignity. Most of the previous studies have been done of maintaining patients' dignity in interaction with healthcare team, but studies on affecting factors of dignity in chronic patients in the society and in interaction with usual people are scarce. We aimed to investigate factors affecting dignity of Iranian patients with MS in daily living and in interaction of them with the society. In this qualitative study, 13 patients with multiple sclerosis were chosen by purposive sampling and semi-structured interviews were conducted until data saturation. The study was done in Tehran, the capital city of Iran. Factors affecting dignity were classified as 'personal factors' and 'social factors'. Personal factors consist of the following subcategories: patients' communication with self, patients' knowledge, patients' values and beliefs and patients' resources. Social factors include others' communication with patients, social knowledge, social values and beliefs and social resources. Multiple personal and social factors interfere in perceived patient dignity. In fact, interaction between personal and social factors can be influential in final perceived dignity. By focusing on whole aspects of the patients' lives, we can identify dignity-promoting or dignity-threatening factors and help patients maintain their dignity by taking appropriate measures for moderating threatening factors and improving dignity enhancing ones. © 2016 Nordic College of Caring Science.

Shorea robusta: A sustainable biomass feedstock

Directory of Open Access Journals (Sweden)

Vishal Kumar Singh

2016-09-01

Full Text Available The biomass feedstock needs to be available in a manner that is sustainable as well as renewable. However, obtaining reliable and cost effective supplies of biomass feedstock produced in a sustainable manner can prove to be difficult. Traditional biomass, mainly in the form of fallen leaves, fuel wood or dried dung, has long been the renewable and sustainable energy source for cooking and heating. Present study accounts for the biomass of fallen leaves of Shorea robusta, also known as sal, sakhua or shala tree, in the campus of BIT Mesra (Ranchi. These leaves are being gathered and burnt rather than being sold commercially. They contain water to varying degrees which affects their energy content. Hence, measurement of moisture content is critical for its biomass assessment. The leaves were collected, weighed, oven dried at 100oC until constant weight, then dry sample was reweighed to calculate the moisture content that has been driven off. By subtraction of moisture content from the initial weight of leaves, biomass was calculated. Using Differential Scanning Calorimeter (DSC the heat content of the leaves was calculated and the elemental analysis of leaf was done by CHNSO elemental analyser. Further, total biomass and carbon content of Sal tree was calculated using allometric equations so as to make a comparison to the biomass stored in dried fallen leaves

High yielding biomass genotypes of willow (Salix spp.) show differences in below ground biomass allocation

International Nuclear Information System (INIS)

Cunniff, Jennifer; Purdy, Sarah J.; Barraclough, Tim J.P.; Castle, March; Maddison, Anne L.; Jones, Laurence E.; Shield, Ian F.; Gregory, Andrew S.; Karp, Angela

2015-01-01

speed and soil characteristics affected biomass allocation

'Biomass lung': primitive biomass combustion and lung disease

International Nuclear Information System (INIS)

Baris, Y. I.; Seyfikli, Z.; Demir, A.; Hoskins, J. A.

2002-01-01

Domestic burning of biomass fuel is one of the most important risk factors for the development of respiratory diseases and infant mortality. The fuel which causes the highest level of disease is dung. In the rural areas of developing countries some 80% of households rely on biomass fuels for cooking and often heating as well and so suffer high indoor air pollution. Even when the fire or stove is outside the home those near it are still exposed to the smoke. In areas where the winters are long and cold the problem is aggravated since the fire or stove is indoors for many months of the year. The consequence of biomass burning is a level of morbidity in those exposed to the smoke as well as mortality. The rural areas of Turkey are among many in the world where biomass is the major fuel source. In this case report 8 patients from rural areas, particularly Anatolia, who used biomass are presented. Many of these are non-smoking, female patients who have respiratory complaints and a clinical picture of the chronic lung diseases which would have been expected if they had been heavy smokers. Typically patients cook on the traditional 'tandir' stove using dung and crop residues as the fuel. Ventilation systems are poor and they are exposed to a high level of smoke pollution leading to cough and dyspnoea. Anthracosis is a common outcome of this level of exposure and several of the patients developed lung tumours. The findings from clinical examination of 8 of these patients (2 M, 6 F) are presented together with their outcome where known. (author)

Genetic architecture and temporal patterns of biomass accumulation in spring barley revealed by image analysis.

Science.gov (United States)

Neumann, Kerstin; Zhao, Yusheng; Chu, Jianting; Keilwagen, Jens; Reif, Jochen C; Kilian, Benjamin; Graner, Andreas

2017-08-10

Genetic mapping of phenotypic traits generally focuses on a single time point, but biomass accumulates continuously during plant development. Resolution of the temporal dynamics that affect biomass recently became feasible using non-destructive imaging. With the aim to identify key genetic factors for vegetative biomass formation from the seedling stage to flowering, we explored growth over time in a diverse collection of two-rowed spring barley accessions. High heritabilities facilitated the temporal analysis of trait relationships and identification of quantitative trait loci (QTL). Biomass QTL tended to persist only a short period during early growth. More persistent QTL were detected around the booting stage. We identified seven major biomass QTL, which together explain 55% of the genetic variance at the seedling stage, and 43% at the booting stage. Three biomass QTL co-located with genes or QTL involved in phenology. The most important locus for biomass was independent from phenology and is located on chromosome 7HL at 141 cM. This locus explained ~20% of the genetic variance, was significant over a long period of time and co-located with HvDIM, a gene involved in brassinosteroid synthesis. Biomass is a dynamic trait and is therefore orchestrated by different QTL during early and late growth stages. Marker-assisted selection for high biomass at booting stage is most effective by also including favorable alleles from seedling biomass QTL. Selection for dynamic QTL may enhance genetic gain for complex traits such as biomass or, in the future, even grain yield.

Factor affecting Agrobacterium -mediated transformation of rice ...

African Journals Online (AJOL)

Potato is a very important food crop and is adversely affected by fungus. Agrobacterium-mediated transformation can play an important role in the improvement of potato. The present study was conducted to optimize the different factors affecting Agrobacterium-mediated transformation of chitinase gene. Nodes were used as ...

Transporter engineering in biomass utilization by yeast.

Science.gov (United States)

Hara, Kiyotaka Y; Kobayashi, Jyumpei; Yamada, Ryosuke; Sasaki, Daisuke; Kuriya, Yuki; Hirono-Hara, Yoko; Ishii, Jun; Araki, Michihiro; Kondo, Akihiko

2017-11-01

Biomass resources are attractive carbon sources for bioproduction because of their sustainability. Many studies have been performed using biomass resources to produce sugars as carbon sources for cell factories. Expression of biomass hydrolyzing enzymes in cell factories is an important approach for constructing biomass-utilizing bioprocesses because external addition of these enzymes is expensive. In particular, yeasts have been extensively engineered to be cell factories that directly utilize biomass because of their manageable responses to many genetic engineering tools, such as gene expression, deletion and editing. Biomass utilizing bioprocesses have also been developed using these genetic engineering tools to construct metabolic pathways. However, sugar input and product output from these cells are critical factors for improving bioproduction along with biomass utilization and metabolic pathways. Transporters are key components for efficient input and output activities. In this review, we focus on transporter engineering in yeast to enhance bioproduction from biomass resources. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences.

Science.gov (United States)

Kurm, Viola; van der Putten, Wim H; Pineda, Ana; Hol, W H Gera

2018-02-12

Plant growth-promoting rhizobacteria (PGPR) strains can influence plant-insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence of rare soil microbe reduction on induced systemic resistance (ISR) in a wild ecotype of Arabidopsis thaliana against the aphid Myzus persicae was investigated. To create a gradient of microbial abundances, soil was inoculated with a serial dilution of a microbial community and responses of Arabidopsis plants that originated from the same site as the soil microbes were tested. Plant biomass, transcription of genes involved in plant defences, and insect performance were measured. In addition, the effects of the PGPR strain Pseudomonas fluorescens SS101 on plant and insect performance were tested under the influence of the various soil dilution treatments. Plant biomass showed a hump-shaped relationship with soil microbial community dilution, independent of aphid or Pseudomonas treatments. Both aphid infestation and inoculation with Pseudomonas reduced plant biomass, and led to downregulation of PR1 (salicylic acid-responsive gene) and CYP79B3 (involved in synthesis of glucosinolates). Aphid performance and gene transcription were unaffected by soil dilution. Neither the loss of rare microbial species, as caused by soil dilution, nor Pseudomonas affect the resistance of A. thaliana against M. persicae. However, both Pseudomonas survival and plant biomass respond to rare species loss. Thus, loss of rare soil microbial species can have a significant impact on both above- and below-ground organisms. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Factors affecting patient dose in diagnostic radiology

International Nuclear Information System (INIS)

Poletti, J.L.

1994-03-01

The report, Factors Affecting Patient Dose in Diagnostic Radiology is divided into three main sections. Part one is introductory and covers the basic principles of x-ray production and image formation. It includes discussion of x-ray generators and x-ray tubes, radiation properties and units, specification and measurement of x-ray beams, methods of patient dose measurement, radiation effects, radiation protection philosophy and finally the essentials of imaging systems. Part two examines factors affecting the x-ray output of x-ray machines and the characteristics of x-ray beams. These include the influence of heat ratings, kVp, waveform, exposure timer, filtration, focus-film distance, beam intensity distribution, x-ray tube age and focal spot size. Part three examines x-ray machine, equipment and patient factors which affect the dose received by individual patients. The factors considered include justification of examinations, choice of examination method, film/screen combinations, kVp, mAs, focus-film distance, collimation and field size, exposure time, projection, scatter, generator calibration errors, waveform, filtration, film processing and patient size. The patient dose implications of fluoroscopy systems, CT scanners, special procedures and mammography are also discussed. The report concludes with a brief discussion of patient dose levels in New Zealand and dose optimisation. 104 refs., 32 figs., 27 tabs

Overview of factors affecting the leachability of nuclear waste forms

International Nuclear Information System (INIS)

Stone, J.A.

1980-01-01

An overview of various factors that affect the leachability of nuclear waste forms is presented. The factors affect primarily the leaching system (temperature, for example), the leachant (pH, for example), or the solid being leached (surface condition, for example). A qualitative understanding exists of the major factors affecting leaching, but further studies are needed to establish leaching mechanisms and develop predictive models. 67 refs

Proceedings of the fifth International Slovak Biomass Forum (ISBF)

International Nuclear Information System (INIS)

2005-02-01

The publication has been set up as a proceedings of the conference dealing with use of biomass for energy production. The main conference topics are focused on the following scopes: Session 1: RES Policies, strategies, political background; Session 2: Bioenergy markets, tools and influence factors; Session 3: Biomass fuels production and trading; Parallel Session 4: Biomass firing technologies; Parallel Session 5: Municipal projects uptake; Parallel Session 6: Biomass large and small CHP; Parallel Session 7: Environmental biomass technologies; Session 8: Biomass projects financing roundtable; In this proceedings 54 contributions is included

Pipelines : moving biomass and energy

Energy Technology Data Exchange (ETDEWEB)

Kumar, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering

2006-07-01

Moving biomass and energy through pipelines was presented. Field sourced biomass utilization for fuel was discussed in terms of competing cost factors; economies of scale; and differing fuel plant sizes. The cost versus scale in a bioenergy facility was illustrated in chart format. The transportation cost of biomass was presented as it is a major component of total biomass processing cost and is in the typical range of 25-45 per cent of total processing costs for truck transport of biomass. Issues in large scale biomass utilization, scale effects in transportation, and components of transport cost were identified. Other topics related to transportation issues included approaches to pipeline transport; cost of wood chips in pipeline transport; and distance variable cost of transporting wood chips by pipeline. Practical applications were also offered. In addition, the presentation provided and illustrated a model for an ethanol plant supplied by truck transport as well as a sample configuration for 19 truck based ethanol plants versus one large facility supplied by truck plus 18 pipelines. Last, pipeline transport of bio-oil and pipeline transport of syngas was discussed. It was concluded that pipeline transport can help in reducing congestion issues in large scale biomass utilization and that it can offer a means to achieve large plant size. Some current research at the University of Alberta on pipeline transport of raw biomass, bio-oil and hydrogen production from biomass for oil sands and pipeline transport was also presented. tabs., figs.

Effects of biomass on dynamics of combustion in circulating fluidized beds

Directory of Open Access Journals (Sweden)

Tourunen Antti

2004-01-01

Full Text Available Fluidized bed technology is very suitable for the combustion of biomass Nevertheless substitution of coal with biomass affects boiler operation and especially dynamics and controllability. Non-homogeneity of biomass and fuel feeding disturbances cause process instability, such as variations in temperatures and pressures, which reduce lifetime of equipment and structures. Because of process instability higher air coefficient must be used in order to avoid CO emissions, which is not economical. Combustion profiles for coal, wood and peat, measured at the VTT Processes Pilot circulating fluidized bed reactor, have been compared. Process stability and char inventories have been studied by the measurements and the model. Biofuel are usually very reactive and their combustion profiles are quite different compared to coals. Because of high reactivity and low char content combustion process with biofuel is very sensitive for fuel feeding. Also low char inventory effect on load changes combined with combustion profile that differs from coals. Because of different combustion profile heat transfer can be a limiting factor in load changes despite the high reactivity and fast oxygen response.

Biomass and oil production by Chlorella vulgaris and four other microalgae - Effects of salinity and other factors.

Science.gov (United States)

Luangpipat, Tiyaporn; Chisti, Yusuf

2017-09-10

Five nominally freshwater microalgae (Chlorella vulgaris, Choricystis minor, Neochloris sp., Pseudococcomyxa simplex, Scenedesmus sp.) with a known ability to produce high-levels of lipids for possible use as fuel oils were evaluated for their ability to thrive and produce lipids in seawater and brackish water. Only C. vulgaris was found to thrive and produce lipids in full strength seawater. Seawater tolerant strains of C. vulgaris are unusual. Lipid productivity in nutrient sufficient seawater exceeded 37mgL -1 d -1 and was nearly 2-fold greater than in freshwater. Although other microalgae such as C. minor had higher lipid productivities (e.g. 45mgL -1 d -1 ), they did not thrive in seawater. The lipid content of the C. vulgaris biomass was nearly 16% by dry weight. The calorific value of the seawater-grown C. vulgaris biomass exceeded 25kJg -1 . Compared to continuously illuminated cultures, a 12/12h light-dark cycle reduced lipid productivity of C. vulgaris by ∼30%, but did not affect the lipid content of the biomass. Biomass yield on phosphate was nearly 27% higher in seawater compared to in freshwater. While C. vulgaris has been extensively studied in freshwater, it has not been examined to any detail in full strength seawater. Studies in seawater are essential for any future large scale production of algal oils for biofuels: seawater is available cheaply and in large amounts whereas there is a global shortage of freshwater. Copyright © 2016 Elsevier B.V. All rights reserved.

SOCIO-ECONOMIC FACTORS AFFECTING APPLE PRODUCTION ...

African Journals Online (AJOL)

ACSS

Research Organisation scientists working directly with apple farmers ... be productive up to 40 years, it was more realistic to consider .... to determine the factors that affect apple production. ..... profit maximising model using flexible production ...

Biomass markets. Growth strategy and challenges for French actors

International Nuclear Information System (INIS)

2015-01-01

This study comprises three reports. The first one is an executive summary which focuses on the main aspects of the evolution of the activity in the biomass sector, and highlights factors of change and their strategic consequences. The second one proposes an overview of the situation of biomass French markets, analyses growth strategies adopted by actors of the biomass sector (development of new production capacities, international growth, development of strategies based on several energies, diversification of prospects, innovation and improvement of installation efficiency), and discusses the main strategic challenges on the medium term. The third report proposes a presentation of the context of French biomass markets (political, regulatory and energetic framework, energetic assessment and assessment of the waste-based sector, economic context, housing stock, and other contextual factors), a presentation of the biomass French market (data for 2005-2013, dynamics of three specific segments: solid biomass, renewable urban wastes, and biogas), and a description of the competitive landscape (economic structure, actors) and of the 15 main actors

Factors Affecting Entrepreneurship and Business Sustainability

Directory of Open Access Journals (Sweden)

Ana Tur-Porcar

2018-02-01

Full Text Available Sustainability is becoming increasingly important for society, and the creation of business ventures is one area where sustainability is critical. We examined the factors affecting actions that are designed to foster business sustainability. These factors are related to the environment, behavior, human relations, and business activity. Based on questionnaire responses from experts, the Analytic Hierarchy Process (AHP method was used to rank sustainable business criteria according to their importance for entrepreneurs starting sustainable businesses. The results indicate that the most important drivers of sustainable entrepreneurship are behavioral factors and business factors. Ethical principles and values, together with competitive intelligence, are crucial for undertaking actions that lead to sustainability.

Biomass Energy Data Book: Edition 4

Energy Technology Data Exchange (ETDEWEB)

Boundy, Robert Gary [ORNL; Diegel, Susan W [ORNL; Wright, Lynn L [ORNL; Davis, Stacy Cagle [ORNL

2011-12-01

The Biomass Energy Data Book is a statistical compendium prepared and published by Oak Ridge National Laboratory (ORNL) under contract with the Biomass Program in the Energy Efficiency and Renewable Energy (EERE) program of the Department of Energy (DOE). Designed for use as a convenient reference, the book represents an assembly and display of statistics and information that characterize the biomass industry, from the production of biomass feedstocks to their end use, including discussions on sustainability. This is the fourth edition of the Biomass Energy Data Book which is only available online in electronic format. There are five main sections to this book. The first section is an introduction which provides an overview of biomass resources and consumption. Following the introduction to biomass, is a section on biofuels which covers ethanol, biodiesel and bio-oil. The biopower section focuses on the use of biomass for electrical power generation and heating. The fourth section is on the developing area of biorefineries, and the fifth section covers feedstocks that are produced and used in the biomass industry. The sources used represent the latest available data. There are also two appendices which include frequently needed conversion factors, a table of selected biomass feedstock characteristics, and discussions on sustainability. A glossary of terms and a list of acronyms are also included for the reader's convenience.

Biomass Energy Data Book: Edition 2

Energy Technology Data Exchange (ETDEWEB)

Wright, Lynn L [ORNL; Boundy, Robert Gary [ORNL; Badger, Philip C [ORNL; Perlack, Robert D [ORNL; Davis, Stacy Cagle [ORNL

2009-12-01

The Biomass Energy Data Book is a statistical compendium prepared and published by Oak Ridge National Laboratory (ORNL) under contract with the Biomass Program in the Energy Efficiency and Renewable Energy (EERE) program of the Department of Energy (DOE). Designed for use as a convenient reference, the book represents an assembly and display of statistics and information that characterize the biomass industry, from the production of biomass feedstocks to their end use, including discussions on sustainability. This is the second edition of the Biomass Energy Data Book which is only available online in electronic format. There are five main sections to this book. The first section is an introduction which provides an overview of biomass resources and consumption. Following the introduction to biomass, is a section on biofuels which covers ethanol, biodiesel and bio-oil. The biopower section focuses on the use of biomass for electrical power generation and heating. The fourth section is on the developing area of biorefineries, and the fifth section covers feedstocks that are produced and used in the biomass industry. The sources used represent the latest available data. There are also four appendices which include frequently needed conversion factors, a table of selected biomass feedstock characteristics, assumptions for selected tables and figures, and discussions on sustainability. A glossary of terms and a list of acronyms are also included for the reader's convenience.

Biomass Energy Data Book: Edition 3

Energy Technology Data Exchange (ETDEWEB)

Boundy, Robert Gary [ORNL; Davis, Stacy Cagle [ORNL

2010-12-01

The Biomass Energy Data Book is a statistical compendium prepared and published by Oak Ridge National Laboratory (ORNL) under contract with the Biomass Program in the Energy Efficiency and Renewable Energy (EERE) program of the Department of Energy (DOE). Designed for use as a convenient reference, the book represents an assembly and display of statistics and information that characterize the biomass industry, from the production of biomass feedstocks to their end use, including discussions on sustainability. This is the third edition of the Biomass Energy Data Book which is only available online in electronic format. There are five main sections to this book. The first section is an introduction which provides an overview of biomass resources and consumption. Following the introduction to biomass, is a section on biofuels which covers ethanol, biodiesel and bio-oil. The biopower section focuses on the use of biomass for electrical power generation and heating. The fourth section is on the developing area of biorefineries, and the fifth section covers feedstocks that are produced and used in the biomass industry. The sources used represent the latest available data. There are also four appendices which include frequently needed conversion factors, a table of selected biomass feedstock characteristics, and discussions on sustainability. A glossary of terms and a list of acronyms are also included for the reader's convenience.

Monitoring coniferous forest biomass change using a Landsat trajectory-based approach

Science.gov (United States)

Magdalena Main-Knorn; Warren B. Cohen; Robert E. Kennedy; Wojciech Grodzki; Dirk Pflugmacher; Patrick Griffiths; Patrick Hostert

2013-01-01

Forest biomass is a major store of carbon and thus plays an important role in the regional and global carbon cycle. Accurate forest carbon sequestration assessment requires estimation of both forest biomass and forest biomass dynamics over time. Forest dynamics are characterized by disturbances and recovery, key processes affecting site productivity and the forest...

Factors Affecting the Productivity of Government Workers

Directory of Open Access Journals (Sweden)

Jerry P. Haenisch

2012-01-01

Full Text Available While there have been a variety of studies concerning government worker motivation and productivity, few, if any, studies have focused specifically on state government workers’ perceptions about what factors affect their productivity. With more than 5 million workers employed by state governments in the United States, any improvement in state workplace productivity could have significant financial and service impact for society. In this study, state government workers identified those factors perceived as most affecting their workplace productivity. Data were collected through a survey offered to state government workers in the state of Wyoming. Factor analysis was used to derive key productivity factors from survey responses. The results indicate that state government workers appreciate having freedom and autonomy, like their jobs and the sense of achievement, and welcome teamwork, but feel limited by poor supervision and management, poor communications, and insufficient budgets and staffing. To improve productivity, the workers would eliminate bureaucracy, supervise better, and improve communication.

Importance of biomass energy sources for Turkey

International Nuclear Information System (INIS)

Demirbas, Ayhan

2008-01-01

Various agricultural residues such as grain dust, crop residues and fruit tree residues are available in Turkey as the sources of biomass energy. Among the biomass energy sources, fuelwood seems to be one of the most interesting because its share of the total energy production of Turkey is high at 21% and the techniques for converting it to useful energy are not necessarily sophisticated. Selection of a particular biomass for energy requirements is influenced by its availability, source and transportation cost, competing uses and prevalent fossil fuel prices. Utilization of biomass is a very attractive energy resource, particularly for developing countries since biomass uses local feedstocks and labor. Like many developing countries, Turkey relies on biomass to provide much of its energy requirement. More efficient use of biomass in producing energy, both electrical and thermal, may allow Turkey to reduce petroleum imports, thus affecting its balance of payments dramatically. Turkey has always been one of the major agricultural countries in the world. The importance of agriculture is increasing due to biomass energy being one of the major resources in Turkey. Biomass waste materials can be used in Turkey to provide centralized, medium- and large-scale production of process heat for electricity production. Turkey's first biomass power project is under development in Adana province, at an installed capacity of 45 MW. Two others, at a total capacity of 30 MW, are at the feasibility study stage in Mersin and Tarsus provinces. Electricity production from biomass has been found to be a promising method in the nearest future in Turkey

Fuel pellets from biomass: The importance of the pelletizing pressure and its dependency on the processing conditions

DEFF Research Database (Denmark)

Stelte, Wolfgang; Holm, Jens K.; Sanadi, Anand R.

2011-01-01

The aim of the present study was to identify the key factors affecting the pelletizing pressure in biomass pelletization processes. The impact of raw material type, pellet length, temperature, moisture content and particle size on the pressure build up in the press channel of a pellet mill...... act as lubricants, lowering the friction between the biomass and the press channel walls. The effect of moisture content on the pelletizing pressure was dependent on the raw material species. Different particle size fractions, from below 0.5 mm up to 2.8 mm diameter, were tested, and it was shown...

Biomass assessment and small scale biomass fired electricity generation in the Green Triangle, Australia

International Nuclear Information System (INIS)

Rodriguez, Luis C.; May, Barrie; Herr, Alexander; O'Connell, Deborah

2011-01-01

Coal fired electricity is a major factor in Australia's greenhouse gas emissions (GHG) emissions. The country has adopted a mandatory renewable energy target (MRET) to ensure that 20% of electricity comes from renewable sources by 2020. In order to support the MRET, a market scheme of tradable Renewable Energy Certificates (RECs) has been implemented since 2001. Generators using biomass from eligible sources are able to contribute to GHG emission reduction through the substitution of coal for electricity production and are eligible to create and trade RECs. This paper quantifies the potential biomass resources available for energy generation from forestry and agriculture in the Green Triangle, one of the most promising Australian Regions for biomass production. We analyse the cost of electricity generation using direct firing of biomass, and estimate the required REC prices to make it competitive with coal fired electricity generation. Major findings suggest that more than 2.6 million tonnes of biomass are produced every year within 200 km of the regional hub of Mount Gambier and biomass fired electricity is viable using feedstock with a plant gate cost of 46 Australian Dollars (AUD) per tonne under the current REC price of 34 AUD per MWh. These findings are then discussed in the context of regional energy security and existing targets and incentives for renewable energies. -- Highlights: → We assessed the biomass production in the Green Triangle. → 2.6 million tonnes of biomass per year are produced within 200 km from Mt Gambier. → Renewable Energy Certificates makes bioenergy competitive with coal electricity. → At a REC price of 34 AUD, biomass of up to 46 AUD/tonne might be used for bionergy

Review: Factors affecting fouling in conventional pens for slaughter pigs

DEFF Research Database (Denmark)

Larsen, Mona Lilian Vestbjerg; Bertelsen, Maja; Pedersen, Lene Juul

2018-01-01

and pigs’ earlier experience. Further, these primary factors are affected by secondary factors such as the shape of the pen, the weight of the pigs and especially the heat balance of the pigs, which is affected by several tertiary factors including, for example, temperature, humidity and draught. Results...

Factors Affecting Prenatal Care Utilization in East Wollega Zone ...

African Journals Online (AJOL)

The objective of the study was to identify factors affecting utilization of prenatal care and skilled birth attendant in East Wollega zone. Prenatal care and skilled birth attendant are crucial factor which affects the health and wellbeing of the mother and newborn and help the women to access skilled assistance, drugs, ...

The quantum walk search algorithm: Factors affecting efficiency

OpenAIRE

Lovett, Neil B.; Everitt, Matthew; Heath, Robert M.; Kendon, Viv

2011-01-01

We numerically study the quantum walk search algorithm of Shenvi, Kempe and Whaley [PRA \\textbf{67} 052307] and the factors which affect its efficiency in finding an individual state from an unsorted set. Previous work has focused purely on the effects of the dimensionality of the dataset to be searched. Here, we consider the effects of interpolating between dimensions, connectivity of the dataset, and the possibility of disorder in the underlying substrate: all these factors affect the effic...

Determining the Factors Affecting Labor Productivity of Nurses

OpenAIRE

Yurdanur Dikmen; Dilek Kara Yilmaz; Handenur Basaran; Nasibe Yagmur Filiz

2016-01-01

Aim: This study was conducted to determine the factors affecting the labor productivity of nurses. Material and Methods: The study which was planned as descriptive and analytical was carried out with 156 nurses who volunteered to participate in the study in a public hospital in the northwest of Turkey. Data was collected with the and ldquo;Participant Presentation Form and rdquo; and the questionnaire including the factors affecting labor productivity which was developed by Ozkoc (2005). ...

[Emission factors and PM chemical composition study of biomass burning in the Yangtze River Delta region].

Science.gov (United States)

Tang, Xi-Bin; Huang, Cheng; Lou, Sheng-Rong; Qiao, Li-Ping; Wang, Hong-Li; Zhou, Min; Chen, Ming-hua; Chen, Chang-Hong; Wang, Qian; Li, Gui-Ling; Li, Li; Huang, Hai-Ying; Zhang, Gang-Feng

2014-05-01

The emission characteristics of five typical crops, including wheat straw, rice straw, oil rape straw, soybean straw and fuel wood, were investigated to explore the gas and particulates emission of typical biomass burning in Yangzi-River-Delta area. The straws were tested both by burning in stove and by burning in the farm with a self-developed measurement system as open burning sources. Both gas and fine particle pollutants were measured in this study as well as the chemical composition of fine particles. The results showed that the average emission factors of CO, NO, and PM2,5 in open farm burning were 28.7 g.kg -1, 1.2 g.kg-1 and 2.65 g kg-1 , respectively. Due to insufficient burning in the low oxygen level environment, the emission factors of stove burning were higher than those of open farm burning, which were 81.9 g kg-1, 2. 1 g.kg -1 and 8.5 gkg -1 , respectively. Oil rape straw had the highest emission factors in all tested straws samples. Carbonaceous matter, including organic carbon(OC) and element carbon(EC) , was the foremost component of PM2, 5from biomass burning. The average mass fractions of OC and EC were (38.92 +/- 13.93)% and (5.66 +/-1.54)% by open farm burning and (26.37 +/- 10. 14)% and (18.97 +/- 10.76)% by stove burning. Water soluble ions such as Cl-and K+ had a large contribution. The average mass fractions of CI- and K+ were (13.27 +/-6. 82)% and (12.41 +/- 3.02)% by open farm burning, and were (16.25 +/- 9.34)% and (13.62 +/- 7.91)% by stove burning. The K +/OC values of particles from wheat straw, rice straw, oil rape straw and soybean straw by open farm burning were 0. 30, 0. 52, 0. 49 and 0. 15, respectively, which can be used to evaluate the influence on the regional air quality in YRD area from biomass burning and provide direct evidence for source apportionment.

Identifying factors affecting optimal management of agricultural water

Directory of Open Access Journals (Sweden)

Masoud Samian

2015-01-01

In addition to quantitative methodology such as descriptive statistics and factor analysis a qualitative methodology was employed for dynamic simulation among variables through Vensim software. In this study, the factor analysis technique was used through the Kaiser-Meyer-Olkin (KMO and Bartlett tests. From the results, four key elements were identified as factors affecting the optimal management of agricultural water in Hamedan area. These factors were institutional and legal factors, technical and knowledge factors, economic factors and social factors.

Factors affecting the runoff response of watersheds to precipitation

OpenAIRE

DROZDOVÁ, Martina

2013-01-01

This bachelor thesis is focused on the factors that affect the drainage basin of the response. It contains a literature review, which deals with the hydrological cycle characteristics of precipitation, surface runoff and flood and erosion protection. The aim of the work is to evaluate the factors that adversely affect the runoff from the catchment.

Economic and Cultural Factors Affecting University Excellence

Science.gov (United States)

Jabnoun, Naceur

2009-01-01

Purpose: The ranking of top universities in the world has generated increased interest in the factors that enhance university performance. The purpose of this paper is to identify economic and cultural factors that affect the number of top ranking universities in each country. Design/methodology/approach: This paper first identifies the number of…

Factors affecting the organization and management of emergency ...

African Journals Online (AJOL)

Factors affecting the organization and management of emergency mass casualty ... service all under a unified command of leadership with a specified job description. Factors identified were: Political will, human resource planning, appropriate ...

Socioeconomic Constraints to Biomass Removal from Forest Lands for Fire Risk Reduction in the Western U.S.

Directory of Open Access Journals (Sweden)

David L. Nicholls

2018-05-01

Full Text Available Many socioeconomic constraints exist for biomass removals from federal lands in the western U.S. We examine several issues of importance, including biomass supply chains and harvesting costs, innovative new uses for bioenergy products, and the policy framework in place to provide incentives for biomass use. Western states vary greatly in the extent and utilization of forest resources, the proportion of land under federal ownership, and community and stakeholder structure and dynamics. Our research—which focused on the socioeconomic factors associated with biomass removal, production, and use—identified several important trends. Long-term stewardship projects could play a role in influencing project economics while being conducive to private investment. State policies are likely to help guide the growth of biomass utilization for energy products. New markets and technologies, such as biofuels, for use in the aviation industry, torrefied wood, mobile pyrolysis, and wood coal cofiring could greatly change the landscape of biomass use. Social needs of residents in wildland urban interfaces will play an important role, especially in an era of megafires. All of these trends—including significant unknowns, like the volatile prices of fossil energy—are likely to affect the economics of biomass removal and use in western forests.

Factors affecting IUCD discontinuation in Nepal

DEFF Research Database (Denmark)

Thapa, Subash; Paudel, Ishwari Sharma; Bhattarai, Sailesh

2015-01-01

Information related to contraception discontinuation, especially in the context of Nepal is very limited. A nested case-control study was carried out to determine the factors affecting discontinuation of intrauterine contraceptive devices (IUCDs). A total of 115 cases (IUCD discontinuers) and 115...

Zooming in and out: Scale dependence of extrinsic and intrinsic factors affecting salt marsh erosion

Science.gov (United States)

Wang, Heng; van der Wal, Daphne; Li, Xiangyu; van Belzen, Jim; Herman, Peter M. J.; Hu, Zhan; Ge, Zhenming; Zhang, Liquan; Bouma, Tjeerd J.

2017-07-01

Salt marshes are valuable ecosystems that provide important ecosystem services. Given the global scale of marsh loss due to climate change and coastal squeeze, there is a pressing need to identify the critical extrinsic (wind exposure and foreshore morphology) and intrinsic factors (soil and vegetation properties) affecting the erosion of salt marsh edges. In this study, we quantified rates of cliff lateral retreat (i.e., the eroding edge of a salt marsh plateau) using a time series of aerial photographs taken over four salt marsh sites in the Westerschelde estuary, the Netherlands. In addition, we experimentally quantified the erodibility of sediment cores collected from the marsh edge of these four marshes using wave tanks. Our results revealed the following: (i) at the large scale, wind exposure and the presence of pioneer vegetation in front of the cliff were the key factors governing cliff retreat rates; (ii) at the intermediate scale, foreshore morphology was partially related to cliff retreat; (iii) at the local scale, the erodibility of the sediment itself at the marsh edge played a large role in determining the cliff retreat rate; and (iv) at the mesocosm scale, cliff erodibility was determined by soil properties and belowground root biomass. Thus, both extrinsic and intrinsic factors determined the fate of the salt marsh but at different scales. Our study highlights the importance of understanding the scale dependence of the factors driving the evolution of salt marsh landscapes.

Pretreatments to enhance the digestibility of lignocellulosic biomass

NARCIS (Netherlands)

Hendriks, A.T.W.M.; Zeeman, G.

2009-01-01

Lignocellulosic biomass represents a rather unused source for biogas and ethanol production. Many factors, like lignin content, crystallinity of cellulose, and particle size, limit the digestibility of the hemicellulose and cellulose present in the lignocellulosic biomass. Pretreatments have as a

Thermal Pretreatment of Wood for Co-gasification/co-firing of Biomass and Coal

Energy Technology Data Exchange (ETDEWEB)

Wang, Ping [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Howard, Bret [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Hedges, Sheila [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Morreale, Bryan [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Van Essendelft, Dirk [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Berry, David [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

2013-10-29

Utilization of biomass as a co-feed in coal and biomass co-firing and co-gasification requires size reduction of the biomass. Reducing biomass to below 0.2 mm without pretreatment is difficult and costly because biomass is fibrous and compressible. Torrefaction is a promising thermal pretreatment process and has the advantages of increasing energy density, improving grindability, producing fuels with more homogenous compositions and hydrophobic behavior. Temperature is the most important factor for the torrefaction process. Biomass grindability is related to cell wall structure, thickness and composition. Thermal treatment such as torrefaction can cause chemical changes that significantly affect the strength of biomass. The objectives of this study are to understand the mechanism by which torrefaction improves the grindability of biomass and discuss suitable temperatures for thermal pretreatment for co-gasification/co-firing of biomass and coal. Wild cherry wood was selected as the model for this study. Samples were prepared by sawing a single tangential section from the heartwood and cutting it into eleven pieces. The samples were consecutively heated at 220, 260, 300, 350, 450 and 550⁰C for 0.5 hr under flowing nitrogen in a tube furnace. Untreated and treated samples were characterized for physical properties (color, dimensions and weight), microstructural changes by SEM, and cell wall composition changes and thermal behaviors by TGA and DSC. The morphology of the wood remained intact through the treatment range but the cell walls were thinner. Thermal treatments were observed to decompose the cell wall components. Hemicellulose decomposed over the range of ~200 to 300⁰C and resulted in weakening of the cell walls and subsequently improved grindability. Furthermore, wood samples treated above 300⁰C lost more than 39% in mass. Therefore, thermal pretreatment above the hemicelluloses decomposition temperature but below 300⁰C is probably sufficient to

Effect of single and mixed polycyclic aromatic hydrocarbon contamination on plant biomass yield and PAH dissipation during phytoremediation.

Science.gov (United States)

Afegbua, Seniyat Larai; Batty, Lesley Claire

2018-04-27

Polycyclic aromatic hydrocarbon (PAH)-contaminated sites have a mixture of PAH of varying concentration which may affect PAH dissipation differently to contamination with a single PAH. In this study, pot experiments investigated the impact of PAH contamination on Medicago sativa, Lolium perenne, and Festuca arundinacea biomass and PAH dissipation from soils spiked with phenanthrene (Phe), fluoranthene (Flu), and benzo[a]pyrene (B[a]P) in single and mixed treatments. Stimulatory or inhibitory effects of PAH contamination on plant biomass yields were not different for the single and mixed PAH treatments. Results showed significant effect of PAH treatments on plant growth with an increased root biomass yield for F. arundinacea in the Phe (175%) and Flu (86%) treatments and a root biomass decrease in the mixed treatment (4%). The mean residual PAHs in the planted treatments and unplanted control for the single treatments were not significantly different. B[a]P dissipation was enhanced for single and mixed treatments (71-72%) with F. arundinacea compared to the unplanted control (24-50%). On the other hand, B[a]P dissipation was inhibited with L. perenne (6%) in the single treatment and M. sativa (11%) and L. perenne (29%) in the mixed treatment. Abiotic processes had greater contribution to PAH dissipation compared to rhizodegradation in both treatments. In most cases, a stimulatory effect of PAH contamination on plant biomass yield without an enhancement of PAH dissipation was observed. Plant species among other factors affect the relative contribution of PAH dissipation mechanisms during phytoremediation. These factors determine the effectiveness and suitability of phytoremediation as a remedial strategy for PAH-contaminated sites. Further studies on impact of PAH contamination, plant selection, and rhizosphere activities on soil microbial community structure and remediation outcome are required.

Factors affecting the design of instrument flight procedures

Directory of Open Access Journals (Sweden)

Ivan FERENCZ

2008-01-01

Full Text Available The article highlights factors, which might affect the design of instrument flight procedures. Ishikawa diagram is used to distribute individual factors into classes, as are People, Methods, Regulations, Tools, Data and Environment.

Factors Affecting Rural Facilitators’ Role: Iran

OpenAIRE

Azimi, Farideh; Kamali, Mohammad Bagher

2011-01-01

This study aimed to examine key factors affecting rural female facilitators’ role in participatory rural development in Tehran Province. Since the researchers intended to have a better insight into the facilitators’ role and employ inquiry as a learning forum for bringing about changes for all participants, they preferred to use a case study based upon an appreciative inquiry method. The study divided the factors affecting the facilitators’ role into two main categories: driving factors...

Psychological factors affecting equine performance

Directory of Open Access Journals (Sweden)

McBride Sebastian D

2012-09-01

Full Text Available Abstract For optimal individual performance within any equestrian discipline horses must be in peak physical condition and have the correct psychological state. This review discusses the psychological factors that affect the performance of the horse and, in turn, identifies areas within the competition horse industry where current behavioral research and established behavioral modification techniques could be applied to further enhance the performance of animals. In particular, the role of affective processes underpinning temperament, mood and emotional reaction in determining discipline-specific performance is discussed. A comparison is then made between the training and the competition environment and the review completes with a discussion on how behavioral modification techniques and general husbandry can be used advantageously from a performance perspective.

Workplace, Biographical and Motivation Factors Affecting ...

African Journals Online (AJOL)

This paper presents the findings of a survey on how workplace, biographical and motivational factors affect the organisational commitment of records officers in federal universities in Nigeria. Single stage random sampling, with equal allocation method, was used to administer questionnaire on 300 sampled participants from ...

Psychological factors affecting equine performance

OpenAIRE

McBride, Sebastian D; Mills, Daniel S

2012-01-01

Abstract For optimal individual performance within any equestrian discipline horses must be in peak physical condition and have the correct psychological state. This review discusses the psychological factors that affect the performance of the horse and, in turn, identifies areas within the competition horse industry where current behavioral research and established behavioral modification techniques could be applied to further enhance the performance of animals. In particular, the role of af...

Physical factors affecting the electrically assisted thermal bitumen recovery

Energy Technology Data Exchange (ETDEWEB)

Bogdanov, I.I.; Torres, J.-A.; Kamp, A.M. [CHLOE, University of Pau (France); Corre, B. [CSTJF, Total (France)

2011-07-01

In the heavy oil industry, thermal processes are used to enhance oil recovery by increasing the reservoir temperature which results in better oil mobility. Low frequency heating (LFH) is a technology using electrical conductivity of connate water to propagate current between electrodes, thus generating heat in the reservoir through the Joule effect. During the preheating and production periods, many physical factors may affect the LFH process and the aim of this study was to determine which factors affect the process and how, using a particular pattern of electrodes. Simulations were conducted using the CMG Stars reservoir simulator under different configurations, conditions and parameters. Important physical properties and operational conditions affecting the LFH process were determined and results showed that convection heat, bulk electrical conductivity and power distribution can be improved by salt water circulation. This paper highlighted the physical factors affecting LFH efficiency and these findings will be useful for future process design.

Development of low cost systems for co-utilisation of biomass in large power plant. Mid term review report

Energy Technology Data Exchange (ETDEWEB)

Livingston, W.R.

2003-07-01

Interest in the cofiring of biomass materials with coal in large coal-fired power stations in the UK has increased significantly in recent years in response to the potential additional income from Renewables Obligation Certificates (ROCs). It is anticipated that most coal-fired power stations in the UK will have the capability to cofire biomass materials by the end of 2003. This mid-term review report examines the various stages in the route to fully commercial operation of biomass cofiring at coal-fired power stations, the availability of suitable biomass materials in the UK and the technical options for cofiring. The factors affecting the economics of biomass cofiring in large coal-fired boilers are discussed including the delivered price of biofuels, the future value of ROCs, the development costs of cofiring projects, the 25% ceiling on cofiring imposed by the Renewables Obligation Order 2002 and the use of preblending. An overview of the current status of cofiring in the UK is presented, which includes a summary of the results of trials already carried out by operators of coal-fired power stations and a discussion of the future prospects for biomass cofiring in the UK.

Estimation and mapping of above ground biomass and carbon of ...

African Journals Online (AJOL)

USER

1Department of Geomatics and Land Management, Makerere University, P.O. Box 7062 ... Biomass is an important parameter for bioenergy modelling, food security, ... –Kyoto climate change agreement on reducing emissions from deforestation and ... the nature of terrain can also affect the amounts of biomass and carbon ...

Spatial modeling of potential woody biomass flow

Science.gov (United States)

Woodam Chung; Nathaniel Anderson

2012-01-01

The flow of woody biomass to end users is determined by economic factors, especially the amount available across a landscape and delivery costs of bioenergy facilities. The objective of this study develop methodology to quantify landscape-level stocks and potential biomass flows using the currently available spatial database road network analysis tool. We applied this...

Investigation of Factors Affecting Microdialysis Probe Delivery and ...

African Journals Online (AJOL)

HP

Purpose: To investigate in vitro the factors affecting microdialysis probe delivery and recovery of puerarin . Methods: ... methods. Factors such as drug concentration, stirring speed, additives and length of membrane were ... The high performance liquid chromatography ..... Pharmacokinetic Modeling to Investigate Regional.

Personality factors and adult attachment affecting job mobility

NARCIS (Netherlands)

van Vianen, A.E.M.; Feij, J.A.; Krausz, M.; Taris, R.

2003-01-01

Past research has revealed that individuals' job mobility is affected by factors such as job satisfaction, specific career enhancing attributes and job availability. This study examined personality factors predicting voluntary internal and external job mobility. Three types of voluntary job mobility

Parallel factor analysis PARAFAC of process affected water

Energy Technology Data Exchange (ETDEWEB)

Ewanchuk, A.M.; Ulrich, A.C.; Sego, D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering; Alostaz, M. [Thurber Engineering Ltd., Calgary, AB (Canada)

2010-07-01

A parallel factor analysis (PARAFAC) of oil sands process-affected water was presented. Naphthenic acids (NA) are traditionally described as monobasic carboxylic acids. Research has indicated that oil sands NA do not fit classical definitions of NA. Oil sands organic acids have toxic and corrosive properties. When analyzed by fluorescence technology, oil sands process-affected water displays a characteristic peak at 290 nm excitation and approximately 346 nm emission. In this study, a parallel factor analysis (PARAFAC) was used to decompose process-affected water multi-way data into components representing analytes, chemical compounds, and groups of compounds. Water samples from various oil sands operations were analyzed in order to obtain EEMs. The EEMs were then arranged into a large matrix in decreasing process-affected water content for PARAFAC. Data were divided into 5 components. A comparison with commercially prepared NA samples suggested that oil sands NA is fundamentally different. Further research is needed to determine what each of the 5 components represent. tabs., figs.

Economic and Technical Efficiency of the Biomass Industry in China: A Network Data Envelopment Analysis Model Involving Externalities

Directory of Open Access Journals (Sweden)

Qingyou Yan

2017-09-01

Full Text Available This paper proposes the network data envelopment analysis (DEA model accounting for negative externalities and applies it for decomposition of profit inefficiency in the biomass-agriculture circular system (Bio-AG system. A circular structure of the Bio-AG system which is different from the previously applied network structures is assumed. Since the negative externalities (i.e., pollutant emissions from the biomass industry occur in the Bio-AG system, the property rights are taken into consideration to model the externalities-adjusted profits. Therefore, the changes in profits due to changes in the property rights (assuming no property rights, allocating property rights to agricultural sector, and allocating property rights to biomass power generation sector are quantified. Further, the decomposition shows that the biomass power generation sector is less affected by technical inefficiency if contrasted to allocative inefficiency in terms of the profit loss. The findings suggest that the biomass power generation technology influences the profits of the biomass industry. What is more, the inefficient allocation of resources is now the key factor undermining performance of the biomass industry. Therefore, the government should adopt measures to improve the allocation of resources and prevent excessive investments or development of less efficient technologies.

Soil, biomass, and management of semi-natural vegetation. II. Factors controlling species diversity

NARCIS (Netherlands)

Schaffers, A.P.

2002-01-01

Using a wide range of conditions and plant community types, species diversity was investigated in relation to edaphic and non-edaphic site conditions, management, and biomass characteristics. Both standing biomass and aboveground production were investigated, and their effects compared. Three

Factors affecting the performance of professional nurses in Namibia

Directory of Open Access Journals (Sweden)

Magdalene H. Awases

2013-04-01

Objectives: The aim of the present study was to identify factors affecting the performance of professional nurses in Namibia. Method: A quantitative, descriptive survey was used to collect data by means of a questionnaire. A random sample of 180 professional nurses was selected from six hospitals in three regions of Namibia. Results: Factors affecting the performance of nurses negatively were identified such as: lack of recognition of employees who are performing well, quality performance outcomes and an absence of a formal performance appraisal system and poor working conditions. Various factors contribute to both the positive and negative performance of professional nurses in Namibia. Strategies were developed for addressing the negative factors that could positively affect the performance of professional nurses in Namibia. Conclusions: This study emphasises the importance of developing strategies to promote the performance of nurses; build knowledge and expertise; develop mechanisms for improving the performance of nurses; expand leadership and management capacity; and generate information and knowledge through research.

A spatial evaluation of forest biomass usage using GIS

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, Tsuguki; Yamagata, Yoshiki [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba-shi, Ibaraki-ken 305-8506 (Japan); Inoue, Keisuke; Kagemoto, Hiroshi [The University of Tokyo (Japan); Iwao, Koki [National Institute of Advanced Industrial Science and Technology (Japan)

2009-01-15

We conducted a spatial evaluation of forest biomass usage using a geographic information system (GIS) for the Japanese town of Yusuhara. In Japan, over 60% of the land is covered with forest, of which at least 40% is artificial forest. However, because of high labor costs, the profitability of forestry is decreasing, so timber cultivation is not done to the extent that it could be, and thinning has to be subsidized. Under these circumstances, much of the forest is deteriorating. Most of the thinning is accounted for by throwaway thinning, in which the resulting wood is not used. However, with the steep rise in oil prices and the intensification of global warming concerns, expectations are rising for the use of biomass energy from thinned timber that has previously been discarded. If thinned timber, logging residues, and offcuts are utilized for biomass energy and their economic value becomes apparent, profitability will improve for both final cutting and thinning. And in addition to forestry activities being invigorated, it will be possible for some of the deteriorating forests (which have associated dangers such as landslides) to recover. However, using thinned timber and logging residues is problematic in that profitability is affected by harvesting costs. Harvesting costs are largely determined by geographic factors and are higher for more distant stands. Accordingly, in this article, operational costs for different stands are calculated using GIS and matched with total demand in the subject region. In addition, stands with lower operational costs are identified and an investigation of a highly feasible use of forest biomass is carried out. (author)

Agricultural factors affecting Fusarium communities in wheat kernels.

Science.gov (United States)

Karlsson, Ida; Friberg, Hanna; Kolseth, Anna-Karin; Steinberg, Christian; Persson, Paula

2017-07-03

Fusarium head blight (FHB) is a devastating disease of cereals caused by Fusarium fungi. The disease is of great economic importance especially owing to reduced grain quality due to contamination by a range of mycotoxins produced by Fusarium. Disease control and prediction is difficult because of the many Fusarium species associated with FHB. Different species may respond differently to control methods and can have both competitive and synergistic interactions. Therefore, it is important to understand how agricultural practices affect Fusarium at the community level. Lower levels of Fusarium mycotoxin contamination of organically produced cereals compared with conventionally produced have been reported, but the causes of these differences are not well understood. The aim of our study was to investigate the effect of agricultural factors on Fusarium abundance and community composition in different cropping systems. Winter wheat kernels were collected from 18 organically and conventionally cultivated fields in Sweden, paired based on their geographical distance and the wheat cultivar grown. We characterised the Fusarium community in harvested wheat kernels using 454 sequencing of translation elongation factor 1-α amplicons. In addition, we quantified Fusarium spp. using real-time PCR to reveal differences in biomass between fields. We identified 12 Fusarium operational taxonomic units (OTUs) with a median of 4.5 OTUs per field. Fusarium graminearum was the most abundant species, while F. avenaceum had the highest occurrence. The abundance of Fusarium spp. ranged two orders of magnitude between fields. Two pairs of Fusarium species co-occurred between fields: F. poae with F. tricinctum and F. culmorum with F. sporotrichoides. We could not detect any difference in Fusarium communities between the organic and conventional systems. However, agricultural intensity, measured as the number of pesticide applications and the amount of nitrogen fertiliser applied, had an

Hydration properties of briquetted wheat straw biomass feedstock

DEFF Research Database (Denmark)

Zhang, Heng; Fredriksson, Maria; Mravec, Jozef

2017-01-01

Biomass densification elevates the bulk density of the biomass, providing assistance in biomass handling, transportation, and storage. However, the density and the chemical/physical properties of the lignocellulosic biomass are affected. This study examined the changes introduced by a briquetting...... process with the aim of subsequent processing for 2nd generation bioethanol production. The hydration properties of the unprocessed and briquetted wheat straw were characterized for water absorption via low field nuclear magnetic resonance and sorption balance measurements. The water was absorbed more...... rapidly and was more constrained in the briquetted straw compared to the unprocessed straw, potentially due to the smaller fiber size and less intracellular air of the briquetted straw. However, for the unprocessed and briquetted wheat straw there was no difference between the hygroscopic sorption...

Application of Molecular Sieves in Transformations of Biomass and Biomass- Derived Feedstocks

Czech Academy of Sciences Publication Activity Database

Kubička, D.; Kubičková, I.; Čejka, Jiří

2013-01-01

Roč. 55, č. 1 (2013), s. 1-78 ISSN 0161-4940 R&D Projects: GA ČR GBP106/12/G015 Institutional support: RVO:61388955 Keywords : biomass * molecular sieves * zeolites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.111, year: 2013

Analyses of biomass burning contribution to aerosol in Zhengzhou during wheat harvest season in 2015

Science.gov (United States)

Chen, Hongyang; Yin, Shasha; Li, Xiao; Wang, Jia; Zhang, Ruiqin

2018-07-01

Ambient PM2.5 samples were collected in suburban area of Zhengzhou, China to investigate the impact of straw open burning on local aerosol during wheat harvest season in 2015. Secondary formation and accumulation processes were found under unfavorable meteorological conditions through the chemical composition analysis in PM2.5. And spatial and temporal variation of the agricultural activities were observed through MODIS fire spots data combined with back trajectory analysis. Results showed elevated levoglucosan was affected directly during biomass burning episodes and transportation periods. In order to estimate the contribution, levoglucosan/K+ combined with levoglucosan/mannosan were analyzed to identify biomass burning sources. And the results showed that levoglucosan were emitted from straw burning mixing with softwood combustion during the study period, emphasizing that wood combustion for households was non-negligible which consists part of the levoglucosan background in Zhengzhou aerosol. Based on emission factors (levoglucosan/OC or levoglucosan/PM2.5) summarized by laboratory simulation experiments, the study period was divided into 7 depending on the former characteristics to estimate the contribution of biomass burning to aerosol, and the average contributions of biomass burning emission to OC and PM2.5 were 46% and 13% relatively, indicating biomass burning have a significant impact on ambient aerosol levels during harvest season.

Biomass Resource Assessment and Existing Biomass Use in the Madhya Pradesh, Maharashtra, and Tamil Nadu States of India

Directory of Open Access Journals (Sweden)

Karthikeyan Natarajan

2015-05-01

Full Text Available India is experiencing energy crisis and a widening gap between energy supply and demand. The country is, however, endowed with considerable, commercially and technically available renewable resources, from which surplus agro-biomass is of great importance and a relatively untapped resource. In the policy making process, knowledge of existing biomass use, degree of social reliance, and degree of biomass availability for energy production is unequivocal and pre-conditional. Field observations, documentation, and fill-in sheet tools were used to investigate the potential of biomass resources and the existing domestic, commercial, and industrial uses of biomass in selected Indian states. To do so, a team of field observers/supervisors visited three Indian states namely: Maharashtra (MH, Madhya Pradesh (MP, and Tamil Nadu (TN. Two districts from each state were selected to collect data regarding the use of biomass and the extent of biomass availability for energy production. In total, 471 farmers were interviewed, and approximately 75 farmers with various land holdings have been interviewed in each district. The existing uses of biomass have been documented in this survey study and the results show that the majority of biomass is used as fodder for domestic livestock followed by in-site ploughing, leaving trivial surplus quantities for other productive uses. Biomass for cooking appeared to be insignificant due to the availability and access to Liquefied Petroleum Gas (LPG cylinders in the surveyed districts. Opportunities exist to utilize roadside-dumped biomass, in-site burnt biomass, and a share of biomass used for ploughing. The GIS-based maps show that biomass availability varies considerably across the Taluks of the surveyed districts, and is highly dependent on a number of enviromental and socio-cultural factors. Developing competitive bioenergy market and enhancing and promoting access to more LPG fuel connections seem an appropriate socio

Bottom-up and top-down human impacts interact to affect a protected coastal Chilean marsh.

Science.gov (United States)

Fariña, José M; He, Qiang; Silliman, Brian R; Bertness, Mark D

2016-03-01

Many ecosystems, even in protected areas, experience multiple anthropogenic impacts. While anthropogenic modification of bottom-up (e.g., eutrophication) and top-down (e.g., livestock grazing) forcing often co-occurs, whether these factors counteract or have additive or synergistic effects on ecosystems is poorly understood. In a Chilean bio-reserve, we examined the interactive impacts of eutrophication and illegal livestock grazing on plant growth with a 4-yr fertilization by cattle exclusion experiment. Cattle grazing generally decreased plant biomass, but had synergistic, additive, and antagonistic interactions with fertilization in the low, middle, and high marsh zones, respectively. In the low marsh, fertilization increased plant biomass by 112%, cattle grazing decreased it by 96%, and together they decreased plant biomass by 77%. In the middle marsh, fertilization increased plant biomass by 47%, cattle grazing decreased it by 37%, and together they did not affect plant biomass. In the high marsh, fertilization and cattle grazing decreased plant biomass by 81% and 92%, respectively, but together they increased plant biomass by 42%. These interactions were also found to be species specific. Different responses of plants to fertilization and cattle grazing were likely responsible for these variable interactions. Thus, common bottom-up and top-down human impacts can interact in different ways to affect communities even within a single ecosystem. Incorporating this knowledge into conservation actions will improve ecosystem management in a time when ecosystems are increasingly challenged by multiple interacting human impacts.

Reliable Biomass Supply Chain Design under Feedstock Seasonality and Probabilistic Facility Disruptions

Directory of Open Access Journals (Sweden)

Zhixue Liu

2017-11-01

Full Text Available While biomass has been recognized as an important renewable energy source which has a range of positive impacts on the economy, environment, and society, the existence of feedstock seasonality and risk of service disruptions at collection facilities potentially compromises the efficiency and reliability of the energy supply system. In this paper, we consider reliable supply chain design for biomass collection against feedstock seasonality and time-varying disruption risks. We optimize facility location, inventory, biomass quantity, and shipment decisions in a multi-period planning horizon setting. A real-world case in Hubei, China is studied to offer managerial insights. Our computational results show that: (1 the disruption risk significantly affects both the optimal facility locations and the supply chain cost; (2 no matter how the failure probability changes, setting backup facilities can significantly decrease the total cost; and (3 the feedstock seasonality does not affect locations of the collection facilities, but it affects the allocations of collection facilities and brings higher inventory cost for the biomass supply chain.

A Study of Factors Affecting the Renewal of Health Insurance Policy

OpenAIRE

Bhat Ramesh; Jain Nishant

2007-01-01

Health insurance policies are generally one-year policies and to remain part of the insurance poll, policyholders are required to renew their policies each year. Understanding the factors that affect the demand and renewal decisions to continue in health insurance programme is imperative for future growth and development of the insurance sector. We extend our previous work on factors affecting the decision to purchase health insurance to understand the factors affecting the renewal of insuran...

Factors Affecting Faculty Web Portal Usability

Science.gov (United States)

Bringula, Rex P.; Basa, Roselle S.

2011-01-01

The study investigated the factors that might significantly affect web portal usability. Results of the study were intended to serve as inputs for faculty web portal development of the University of the East-Manila. Descriptive statistics utilized questionnaire data from 82 faculty members. The data showed that most of the respondents were…

Integration of biomass into urban energy systems for heat and power. Part II: Sensitivity assessment of main techno-economic factors

International Nuclear Information System (INIS)

Pantaleo, Antonio M.; Giarola, Sara; Bauen, Ausilio; Shah, Nilay

2014-01-01

Highlights: • Application of a MILP tool for optimal sizing and location of heating and CHP plants to serve residential energy demand. • Trade-offs between local vs centralized heat generation, district heating vs natural gas distribution systems. • Assessment of the key factors influencing the use of biomass and district heating in residential areas. - Abstract: The paper presents the application of a mixed integer linear programming (MILP) methodology to optimize multi-biomass and natural gas supply chain strategic design for heat and power generation in urban areas. The focus is on spatial and temporal allocation of biomass supply, storage, processing, transport and energy conversion (heat and CHP) to match the heat demand of residential end users. The main aim lies on the assessment of the trade-offs between centralized district heating plants and local heat generation systems, and on the decoupling of the biomass processing and biofuel energy conversion steps. After a brief description of the methodology, which is presented in detail in Part I of the research, an application to a generic urban area is proposed. Moreover, the influence of energy demand typologies (urban areas energy density, heat consumption patterns, buildings energy efficiency levels, baseline energy costs and available infrastructures) and specific constraints of urban areas (transport logistics, air emission levels, space availability) on the selection of optimal bioenergy pathways for heat and power is assessed, by means of sensitivity analysis. On the basis of these results, broad considerations about the key factors influencing the use of bioenergy into urban energy systems are proposed. Potential further applications of this model are also described, together with main barriers for development of bioenergy routes for urban areas

Evidence of Biomass Smoke Exposure as a Causative Factor for the Development of COPD

Directory of Open Access Journals (Sweden)

Sarah J. Capistrano

2017-12-01

Full Text Available Chronic obstructive pulmonary disease (COPD is a progressive disease of the lungs characterised by chronic inflammation, obstruction of airways, and destruction of the parenchyma (emphysema. These changes gradually impair lung function and prevent normal breathing. In 2002, COPD was the fifth leading cause of death, and is estimated by the World Health Organisation (WHO to become the third by 2020. Cigarette smokers are thought to be the most at risk of developing COPD. However, recent studies have shown that people with life-long exposure to biomass smoke are also at high risk of developing COPD. Most common in developing countries, biomass fuels such as wood and coal are used for cooking and heating indoors on a daily basis. Women and children have the highest amounts of exposures and are therefore more likely to develop the disease. Despite epidemiological studies providing evidence of the causative relationship between biomass smoke and COPD, there are still limited mechanistic studies on how biomass smoke causes, and contributes to the progression of COPD. This review will focus upon why biomass fuels are used, and their relationship to COPD. It will also suggest methodological approaches to model biomass exposure in vitro and in vivo.

Influence of biomass burning from South Asia at a high-altitude mountain receptor site in China

Directory of Open Access Journals (Sweden)

J. Zheng

2017-06-01

Full Text Available Highly time-resolved in situ measurements of airborne particles were conducted at Mt. Yulong (3410 m above sea level on the southeastern edge of the Tibetan Plateau in China from 22 March to 14 April 2015. The detailed chemical composition was measured by a high-resolution time-of-flight aerosol mass spectrometer together with other online instruments. The average mass concentration of the submicron particles (PM1 was 5.7 ± 5.4 µg m−3 during the field campaign, ranging from 0.1 up to 33.3 µg m−3. Organic aerosol (OA was the dominant component in PM1, with a fraction of 68 %. Three OA factors, i.e., biomass burning organic aerosol (BBOA, biomass-burning-influenced oxygenated organic aerosol (OOA-BB and oxygenated organic aerosol (OOA, were resolved using positive matrix factorization analysis. The two oxygenated OA factors accounted for 87 % of the total OA mass. Three biomass burning events were identified by examining the enhancement of black carbon concentrations and the f60 (the ratio of the signal at m∕z 60 from the mass spectrum to the total signal of OA. Back trajectories of air masses and satellite fire map data were integrated to identify the biomass burning locations and pollutant transport. The western air masses from South Asia with active biomass burning activities transported large amounts of air pollutants, resulting in elevated organic concentrations up to 4-fold higher than those of the background conditions. This study at Mt. Yulong characterizes the tropospheric background aerosols of the Tibetan Plateau during pre-monsoon season and provides clear evidence that the southeastern edge of the Tibetan Plateau was affected by the transport of anthropogenic aerosols from South Asia.

Influence of biomass burning from South Asia at a high-altitude mountain receptor site in China

Science.gov (United States)

Zheng, Jing; Hu, Min; Du, Zhuofei; Shang, Dongjie; Gong, Zhaoheng; Qin, Yanhong; Fang, Jingyao; Gu, Fangting; Li, Mengren; Peng, Jianfei; Li, Jie; Zhang, Yuqia; Huang, Xiaofeng; He, Lingyan; Wu, Yusheng; Guo, Song

2017-06-01

Highly time-resolved in situ measurements of airborne particles were conducted at Mt. Yulong (3410 m above sea level) on the southeastern edge of the Tibetan Plateau in China from 22 March to 14 April 2015. The detailed chemical composition was measured by a high-resolution time-of-flight aerosol mass spectrometer together with other online instruments. The average mass concentration of the submicron particles (PM1) was 5.7 ± 5.4 µg m-3 during the field campaign, ranging from 0.1 up to 33.3 µg m-3. Organic aerosol (OA) was the dominant component in PM1, with a fraction of 68 %. Three OA factors, i.e., biomass burning organic aerosol (BBOA), biomass-burning-influenced oxygenated organic aerosol (OOA-BB) and oxygenated organic aerosol (OOA), were resolved using positive matrix factorization analysis. The two oxygenated OA factors accounted for 87 % of the total OA mass. Three biomass burning events were identified by examining the enhancement of black carbon concentrations and the f60 (the ratio of the signal at m/z 60 from the mass spectrum to the total signal of OA). Back trajectories of air masses and satellite fire map data were integrated to identify the biomass burning locations and pollutant transport. The western air masses from South Asia with active biomass burning activities transported large amounts of air pollutants, resulting in elevated organic concentrations up to 4-fold higher than those of the background conditions. This study at Mt. Yulong characterizes the tropospheric background aerosols of the Tibetan Plateau during pre-monsoon season and provides clear evidence that the southeastern edge of the Tibetan Plateau was affected by the transport of anthropogenic aerosols from South Asia.

A mathematical model for the effects of volume fraction and fiber aspect ratio of biomass mixture during enzymatic hydrolysis

Science.gov (United States)

Jamil, Norazaliza Mohd; Wang, Qi

2017-09-01

Renewable energy or biofuel from lignocellulosic biomass is an alternative way to replace the depleting fossil fuels. The production cost can be reduced by increasing the concentration of biomass particles. However, lignocellulosic biomass is a suspension of natural fibres, and processing at high solid concentration is a challenging task. Thus, understanding the factors that affect the rheology of biomass suspension is crucial in order to maximize the production at a minimum cost. Our aim was to develop a mathematical model for enzymatic hydrolysis of cellulose by combining three scales: the macroscopic flow field, the mesoscopic particle orientation, and the microscopic reactive kinetics. The governing equations for the flow field, particle stress, kinetic equations, and particle orientation were coupled and were simultaneously solved using a finite element method based software, COMSOL. One of the main results was the changes in rheology of biomass suspension were not only due to the decrease in volume fraction of particles, but also due the types of fibres. The results from the simulation model agreed qualitatively with the experimental findings. This approach has enables us to obtain better predictive capabilities, hence increasing our understanding on the behaviour of biomass suspension.

Gender factors affecting female labour input in the Nigerian ...

African Journals Online (AJOL)

Gender factors affecting female labour input in the Nigerian University system. ... which mostly affect women‟s job performance in the Nigerian university system. ... are essential in building a gender-friendly university work environment.

Material and operating variables affecting the physical quality of biomass briquettes

Energy Technology Data Exchange (ETDEWEB)

Song, Y.; Xin, M. [Shenyang Agricultural Univ., Shenyang (China). College of Engineering; Tumuluru, J.S.; Iroba, K.L.; Tabil, L.G.; Meda, V. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Agricultural and Bioresource Engineering

2010-07-01

Although biomass is an environmentally sound substitute for fossil fuels, its low bulk density makes it very difficult and costly to transport and handle. This challenge can be addressed by densifying the biomass to a high density product like briquettes. Briquetting is influenced by several material properties such as moisture content, particle size distribution, and some operating variables such as temperature and densification pressure. This paper reported on a study in which briquettes were produced with barley straw, canola straw, oat straw, and wheat straw. The chopped samples were densified using a laboratory hydraulic press briquetting machine at pressure levels of 7.5, 10, and 12.5 MPa and at temperatures of 90, 110 and 130 degrees C. Three moisture content levels and 3 levels of particle size were used. Ten briquettes were manufactured for each treatment combination. The dimensions of all the samples were measured after compression. The samples were then stored in sealed plastic bags in a controlled environment. Durability, dimensional stability, and moisture content tests were conducted after 2 weeks of storage. The study showed that moisture content plays a key role in briquetting.

Health impacts of anthropogenic biomass burning in the developed world.

Science.gov (United States)

Sigsgaard, Torben; Forsberg, Bertil; Annesi-Maesano, Isabella; Blomberg, Anders; Bølling, Anette; Boman, Christoffer; Bønløkke, Jakob; Brauer, Michael; Bruce, Nigel; Héroux, Marie-Eve; Hirvonen, Maija-Riitta; Kelly, Frank; Künzli, Nino; Lundbäck, Bo; Moshammer, Hanns; Noonan, Curtis; Pagels, Joachim; Sallsten, Gerd; Sculier, Jean-Paul; Brunekreef, Bert

2015-12-01

Climate change policies have stimulated a shift towards renewable energy sources such as biomass. The economic crisis of 2008 has also increased the practice of household biomass burning as it is often cheaper than using oil, gas or electricity for heating. As a result, household biomass combustion is becoming an important source of air pollutants in the European Union.This position paper discusses the contribution of biomass combustion to pollution levels in Europe, and the emerging evidence on the adverse health effects of biomass combustion products.Epidemiological studies in the developed world have documented associations between indoor and outdoor exposure to biomass combustion products and a range of adverse health effects. A conservative estimate of the current contribution of biomass smoke to premature mortality in Europe amounts to at least 40 000 deaths per year.We conclude that emissions from current biomass combustion products negatively affect respiratory and, possibly, cardiovascular health in Europe. Biomass combustion emissions, in contrast to emissions from most other sources of air pollution, are increasing. More needs to be done to further document the health effects of biomass combustion in Europe, and to reduce emissions of harmful biomass combustion products to protect public health. Copyright ©ERS 2015.

Investigation of Factors Affecting Microdialysis Probe Delivery and ...

African Journals Online (AJOL)

Purpose: To investigate in vitro the factors affecting microdialysis probe delivery and recovery of puerarin. Methods: The recovery and delivery of puerarin were tested for extraction efficiency and retro-dialysis methods. Factors such as drug concentration, stirring speed, additives and length of membrane were studied to ...

Investigation of Factors Affecting Microdialysis Probe Delivery and ...

African Journals Online (AJOL)

Purpose: To investigate in vitro the factors affecting microdialysis probe delivery and recovery of puerarin . Methods: The recovery and delivery of puerarin were tested for extraction efficiency and retro-dialysis methods. Factors such as drug concentration, stirring speed, additives and length of membrane were studied to ...

7339 BASELINE SURVEY ON FACTORS AFFECTING SORGHUM ...

African Journals Online (AJOL)

muuicathy

2013-01-01

Jan 1, 2013 ... factors affecting sorghum production and the sorghum farming ... The informal seed system includes methods such as retaining seed on-farm from ..... Jaetzold R and H Schmidt Farm Management Handbook of Kenya, Ministry.

The co-integration analysis of factors affecting electricity consumption : a case study of Thailand

Energy Technology Data Exchange (ETDEWEB)

Kongruang, C. [Thaksin Univ., Songkhla (Thailand). Faculty of Economics and Business; Waewsak, J. [Thaksin Univ., Phatthalung (Thailand). Dept. of Physics, Solar and Wind Energy Research Lab

2008-07-01

A study was conducted in which the main determinants of electricity demand in Thailand were investigated. Time-series analysis methods were used, notably the unit root test, the Johansen co-integration test and an error correction model (ECM). The objective was to determine the factors affecting short and long-run electricity consumption. This paper presented annual time series data from 1971 to 2006. The unit root test revealed that all series are non-stationary. The Johansen co-integration test revealed the co-integration between variables and the existence of the long-term relationship between them. Electricity consumption accelerated with the increase in gross domestic product (GDP) and population. In contrast, an increase in commodity price would reduce electricity consumption. The coefficient of population indicated that an increase of 1 million in total population would result in an increase in electricity consumption of 0.099 per cent. Last, the results of ECM revealed that nearly 21 per cent of long-term disequilibrium is adjusted to the current period. The factors that affect electricity consumption include GDP growth, inflation rate and population growth. It was concluded that Thailand should prepare for additional power generation from clean energy sources such as solar, biomass and wind energy. Thailand's Energy Policy and Planning Office revealed that electricity consumption in 2008 would be over 130,000 GWh with per capita consumption at nearly 2,000 kWh. The power peak demand will be nearly 24,000 MW in 2008. This result was based on the forecasting model that considered only GDP growth. However, electricity consumption depends not only on the GDP growth, but also upon the other key variables such as population, electricity selling price, consumer price index and temperature. 17 refs., 5 tabs., 4 figs.

Analysis of Economic Factors Affecting Stock Market

OpenAIRE

Xie, Linyin

2010-01-01

This dissertation concentrates on analysis of economic factors affecting Chinese stock market through examining relationship between stock market index and economic factors. Six economic variables are examined: industrial production, money supply 1, money supply 2, exchange rate, long-term government bond yield and real estate total value. Stock market comprises fixed interest stocks and equities shares. In this dissertation, stock market is restricted to equity market. The stock price in thi...

Woody biomass availability for bioethanol conversion in Mississippi

International Nuclear Information System (INIS)

Perez-Verdin, Gustavo; Grebner, Donald L.; Sun, Changyou; Munn, Ian A.; Schultz, Emily B.; Matney, Thomas G.

2009-01-01

This study evaluated woody biomass from logging residues, small-diameter trees, mill residues, and urban waste as a feedstock for cellulosic ethanol conversion in Mississippi. The focus on Mississippi was to assess in-state regional variations and provide specific information of biomass estimates for those facilities interested in locating in Mississippi. Supply and cost of four woody biomass sources were derived from Forest Inventory Analysis (FIA) information, a recent forest inventory conducted by the Mississippi Institute for Forest Inventory, and primary production costs. According to our analysis, about 4.0 million dry tons of woody biomass are available for production of up to 1.2 billion liters of ethanol each year in Mississippi. The feedstock consists of 69% logging residues, 21% small-diameter trees, 7% urban waste, and 3% mill residues. Of the total, 3.1 million dry tons (930 million liters of ethanol) can be produced for $34 dry ton -1 or less. Woody biomass from small-diameter trees is more expensive than other sources of biomass. Transportation costs accounted for the majority of total production costs. A sensitivity analysis indicates that the largest impacts in production costs of ethanol come from stumpage price of woody biomass and technological efficiency. These results provide a valuable decision support tool for resource managers and industries in identifying parameters that affect resource magnitude, type, and location of woody biomass feedstocks in Mississippi. (author)

Factors Affecting Learning Among Undergraduate Nursing Students: Cross-Sectional Survey

Directory of Open Access Journals (Sweden)

Linu Sara George

2017-11-01

Full Text Available Introduction: Nursing education expects the students to be competent enough to render quality care for their patients in hospital as well as community setting. To reach the level of expected competency, the students must undergo vigorous training during their undergraduate education. The learning experience of the students is influenced by many factors. Aim: To identify the factors, affecting learning as perceived by the students. Materials and Methods: This descriptive survey was conducted among 414 undergraduate nursing students enrolled in selected Nursing Colleges. Background information was collected using Demographic Proforma and the factors affecting learning were identified using Likert Scale. Factors were identified by exploratory factor analysis using extraction method of principal component analysis with varimax rotation. Results: Majority (73.7% of the samples were between 22-25 years of age, 93.2% were females, most (38.9% were studying in the fourth year of nursing, 50% of the students enrolled in the study had chosen nursing as a career due to job security in future, 58.7% students did not spent time every day for their studies and majority (89.1% had English as their medium of instruction in Pre-university college. Factor analysis identified five factors (Learning environment, Supportive services, Teacher characteristics, Learner challenges and Personal factors that affect the student learning. Conclusion: From the present study it can be concluded that perception of students do have an influence on factors affecting learning. The study findings will help the faculty members to bring in changes for the best learning outcome.

Biomass saccharification is largely enhanced by altering wall polymer features and reducing silicon accumulation in rice cultivars harvested from nitrogen fertilizer supply.

Science.gov (United States)

Zahoor; Sun, Dan; Li, Ying; Wang, Jing; Tu, Yuanyuan; Wang, Yanting; Hu, Zhen; Zhou, Shiguang; Wang, Lingqiang; Xie, Guosheng; Huang, Jianliang; Alam, Aftab; Peng, Liangcai

2017-11-01

In this study, two rice cultivars were collected from experimental fields with seven nitrogen fertilizer treatments. All biomass samples contained significantly increased cellulose contents and reduced silica levels, with variable amounts of hemicellulose and lignin from different nitrogen treatments. Under chemical (NaOH, CaO, H 2 SO 4 ) and physical (hot water) pretreatments, biomass samples exhibited much enhanced hexoses yields from enzymatic hydrolysis, with high bioethanol production from yeast fermentation. Notably, both degree of polymerization (DP) of cellulose and xylose/arabinose (Xyl/Ara) ratio of hemicellulose were reduced in biomass residues, whereas other wall polymer features (cellulose crystallinity and monolignol proportion) were variable. Integrative analysis indicated that cellulose DP, hemicellulosic Xyl/Ara and silica are the major factors that significantly affect cellulose crystallinity and biomass saccharification. Hence, this study has demonstrated that nitrogen fertilizer supply could largely enhance biomass saccharification in rice cultivars, mainly by reducing cellulose DP, hemicellulosic Xyl/Ara and silica in cell walls. Copyright © 2017 Elsevier Ltd. All rights reserved.

Methyl halide emission estimates from domestic biomass burning in Africa

Science.gov (United States)

Mead, M. I.; Khan, M. A. H.; White, I. R.; Nickless, G.; Shallcross, D. E.

Inventories of methyl halide emissions from domestic burning of biomass in Africa, from 1950 to the present day and projected to 2030, have been constructed. By combining emission factors from Andreae and Merlet [2001. Emission of trace gases and aerosols from biomass burning. Global Biogeochemical Cycles 15, 955-966], the biomass burning estimates from Yevich and Logan [2003. An assessment of biofuel use and burning of agricultural waste in the developing world. Global Biogeochemical Cycles 17(4), 1095, doi:10.1029/2002GB001952] and the population data from the UN population division, the emission of methyl halides from domestic biomass usage in Africa has been estimated. Data from this study suggest that methyl halide emissions from domestic biomass burning have increased by a factor of 4-5 from 1950 to 2005 and based on the expected population growth could double over the next 25 years. This estimated change has a non-negligible impact on the atmospheric budgets of methyl halides.

Factors affecting the rural domestic waste generation

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A.R. Darban Astane

2017-12-01

Full Text Available The current study was carried out to evaluate the quantity and quality of rural domestic waste generation and to identify the factors affecting it in rural areas of Khodabandeh county in Zanjan Province, Iran. Waste samplings consisted of 318 rural households in 11 villages. In order to evaluate the quality and quantity of the rural domestic waste, waste production was classified into 12 groups and 2 main groups of organic waste and solid waste. Moreover, kriging interpolation technique in ARC-GIS software was used to evaluate the spatial distribution of the generated domestic waste and ultimately multiple regression analysis was used to evaluate the factors affecting the generation of domestic waste. The results of this study showed that the average waste generated by each person was 0.588 kilograms per day. with the share of organic waste generated by each person being 0.409 kilograms per day and the share of solid waste generated by each person being 0.179 kilograms per day. The results from spatial distribution of waste generation showed a certain pattern in three groups and a higher rate of waste generation in the northern and northwestern parts, especially in the subdistrict. The results of multiple regression analysis showed that the households’ income, assets, age, and personal attitude are respectively the most important variables affecting waste generation. The housholds’ attitude and indigenous knowledge on efficient use of materials are also the key factors which can help reducing waste generation.

An Optimization-Based System Model of Disturbance-Generated Forest Biomass Utilization

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Curry, Guy L.; Coulson, Robert N.; Gan, Jianbang; Tchakerian, Maria D.; Smith, C. Tattersall

2008-01-01

Disturbance-generated biomass results from endogenous and exogenous natural and cultural disturbances that affect the health and productivity of forest ecosystems. These disturbances can create large quantities of plant biomass on predictable cycles. A systems analysis model has been developed to quantify aspects of system capacities (harvest,…

Biomass shock pretreatment

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Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

2014-07-01

Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

Volume and biomass for curlleaf cercocarpus in Nevada

Science.gov (United States)

David C. Chojnacky

1984-01-01

Volume and biomass equations were developed for curlleaf cercocarpus (Cercocarpus ledifolius Nutt.) in the Egan and Schell Mountains near Ely, NV. The equations predict cubic foot volume of wood and bark for variable minimum branch diameters. Wood density factors are given to convert volume predictions to pounds of fiber biomass. The reliability of...

Ranking and evaluating the factors affecting the success of ...

African Journals Online (AJOL)

Ranking and evaluating the factors affecting the success of management team in construction projects. ... Journal of Fundamental and Applied Sciences. Journal Home ... The project management team is one of these important factors.

Trophic diversity, size and biomass spectrum of Bay of Bengal nematodes: A study case on depth and latitudinal patterns

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Ansari, Kapuli Gani Mohamed Thameemul; Lyla, Somasundharanair; Khan, Syed Ajmal; Bhadury, Punyasloke

2017-09-01

Depth and latitudinal patterns of nematode functional attributes were investigated from 35 stations of Bay of Bengal (BoB) continental shelf. We aim to address whether depth and latitudinal variations can modify nematode community structure and their functional attributes (trophic diversity, size and biomass spectra). Global trend of depth and latitudinal related variations have also been noticed from BoB shelf in terms of nematode abundance and species richness, albeit heterogeneity patterns were encountered in functional attributes. Index of trophic diversity values revealed higher trophic diversity across the BoB shelf and suggested variety of food resource availability. However, downstream analysis of trophic status showed depth and latitude specific patterns but not reflected in terms of size and biomass spectrum. The peaks at different positions clearly visualized heterogeneity in distribution patterns for both size and biomass spectrum and also there was evidence of availability of diversified food resources. Nematode biomass spectra (NBS) constructed for nematode communities showed shift in peak biomass values towards lower to moderate size classes particularly in shallower depth but did not get reflected in latitudes. However, Chennai and Parangipettai transects demonstrated shift in peak biomass values towards higher biomass classes explaining the representation of higher nematode abundance. Our findings concluded that depth and latitudes are physical variables; they may not directly affect nematode community structure and functional attributes but they might influence the other factors such as food availability, sediment deposition and settlement rate. Our observations suggest that the local factors (seasonal character) of phytodetrital food flux can be very important for shaping the nematode community structure and success of nematode functional heterogeneity patterns across the Bay of Bengal shelf.

Factors Affecting the Pharmacology of Antibody–Drug Conjugates

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Andrew T. Lucas

2018-02-01

Full Text Available Major advances in therapeutic proteins, including antibody–drug conjugates (ADCs, have created revolutionary drug delivery systems in cancer over the past decade. While these immunoconjugate agents provide several advantages compared to their small-molecule counterparts, their clinical use is still in its infancy. The considerations in their development and clinical use are complex, and consist of multiple components and variables that can affect the pharmacologic characteristics. It is critical to understand the mechanisms employed by ADCs in navigating biological barriers and how these factors affect their biodistribution, delivery to tumors, efficacy, and toxicity. Thus, future studies are warranted to better understand the complex pharmacology and interaction between ADC carriers and biological systems, such as the mononuclear phagocyte system (MPS and tumor microenvironment. This review provides an overview of factors that affect the pharmacologic profiles of ADC therapies that are currently in clinical use and development.

Optimization of Preparation Program for Biomass Based Porous Active Carbon by Response Surface Methodology Based on Adsorptive Property

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ZHANG Hao

2017-06-01

Full Text Available With waste walnut shell as raw material, biomass based porous active carbon was made by microwave oven method. The effects of microwave power, activation time and mass fraction of phosphoric acid on adsorptive property of biomass based porous active carbon in the process of physical activation of active carbon precursor were studied by response surface method and numerical simulation method, the preparation plan of biomass based porous active carbon was optimized, and the optimal biomass based porous active carbon property was characterized. The results show that three factors affect the adsorptive property of biomass based porous active carbon, but the effect of microwave power is obviously more significant than that of mass fraction of phosphoric acid, and the effect of mass fraction of phosphoric acid is more significant than that of activation time. The optimized preparation conditions are:microwave power is 746W, activation time is 11.2min and mass fraction of phosphoric acid is 85.9% in the process of physical activation of activated carbon precursor by microwave heating method. For the optimal biomass based porous active carbon, the adsorption value of iodine is 1074.57mg/g, adsorption value of methylene blue is 294.4mL/g and gain rate is 52.1%.

Factors affecting strategic plan implementation using interpretive structural modeling (ISM).

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Bahadori, Mohammadkarim; Teymourzadeh, Ehsan; Tajik, Hamidreza; Ravangard, Ramin; Raadabadi, Mehdi; Hosseini, Seyed Mojtaba

2018-06-11

Purpose Strategic planning is the best tool for managers seeking an informed presence and participation in the market without surrendering to changes. Strategic planning enables managers to achieve their organizational goals and objectives. Hospital goals, such as improving service quality and increasing patient satisfaction cannot be achieved if agreed strategies are not implemented. The purpose of this paper is to investigate the factors affecting strategic plan implementation in one teaching hospital using interpretive structural modeling (ISM). Design/methodology/approach The authors used a descriptive study involving experts and senior managers; 16 were selected as the study sample using a purposive sampling method. Data were collected using a questionnaire designed and prepared based on previous studies. Data were analyzed using ISM. Findings Five main factors affected strategic plan implementation. Although all five variables and factors are top level, "senior manager awareness and participation in the strategic planning process" and "creating and maintaining team participation in the strategic planning process" had maximum drive power. "Organizational structure effects on the strategic planning process" and "Organizational culture effects on the strategic planning process" had maximum dependence power. Practical implications Identifying factors affecting strategic plan implementation is a basis for healthcare quality improvement by analyzing the relationship among factors and overcoming the barriers. Originality/value The authors used ISM to analyze the relationship between factors affecting strategic plan implementation.

Cofiring versus biomass-fired power plants: GHG (Greenhouse Gases) emissions savings comparison by means of LCA (Life Cycle Assessment) methodology

International Nuclear Information System (INIS)

Sebastian, F.; Royo, J.; Gomez, M.

2011-01-01

One way of producing nearly CO 2 free electricity is by using biomass as a combustible. In many cases, removal of CO 2 in biomass grown is almost the same as the emissions for the bioelectricity production at the power plant. For this reason, bioelectricity is generally considered CO 2 neutral. For large-scale biomass electricity generation two alternatives can be considered: biomass-only fired power plants, or cofiring in an existing coal power plant. Among other factors, two important aspects should be analyzed in order to choose between the two options. Firstly, which is the most appealing alternative if their Greenhouse Gases (GHG) Emissions savings are taken into account. Secondly, which biomass resource is the best, if the highest impact reduction is sought. In order to quantify all the GHG emissions related to each system, a Life Cycle Assessment (LCA) methodology has been performed and all the processes involved in each alternative have been assessed in a cradle-to-grave manner. Sensitivity analyses of the most dominant parameters affecting GHG emissions, and comparisons between the obtained results, have also been carried out.

Factors governing dissolution process of lignocellulosic biomass in ionic liquid: current status, overview and challenges.

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Badgujar, Kirtikumar C; Bhanage, Bhalchandra M

2015-02-01

The utilisation of non-feed lignocellulosic biomass as a source of renewable bio-energy and synthesis of fine chemical products is necessary for the sustainable development. The methods for the dissolution of lignocellulosic biomass in conventional solvents are complex and tedious due to the complex chemical ultra-structure of biomass. In view of this, recent developments for the use of ionic liquid solvent (IL) has received great attention, as ILs can solubilise such complex biomass and thus provides industrial scale-up potential. In this review, we have discussed the state-of-art for the dissolution of lignocellulosic material in representative ILs. Furthermore, various process parameters and their influence for biomass dissolution were reviewed. In addition to this, overview of challenges and opportunities related to this interesting area is presented. Copyright © 2014 Elsevier Ltd. All rights reserved.

Carbon use efficiency (CUE) and biomass turnover of soil microbial communities as affected by bedrock, land management and soil temperature and moisture

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Zheng, Qing; Hu, Yuntao; Richter, Andreas; Wanek, Wolfgang

2017-04-01

Soil microbial carbon use efficiency (CUE), defined as the proportion of organic C taken up that is allocated to microbial growth, represents an important synthetic representation of microbial community C metabolism that describes the flux partitioning between microbial respiration and growth. Therefore, studying microbial CUE is critical for the understanding of soil C cycling. Microbial CUE is thought to vary with environmental conditions (e.g. temperature and soil moisture). Microbial CUE is thought to decrease with increasing temperature and declining soil moisture, as the latter may trigger stress responses (e.g. the synthesis of stress metabolites), which may consequently lower microbial community CUE. However, these effects on microbial CUE have not been adequately measured so far due to methodological restrictions. The most widely used methods for microbial CUE estimation are based on tracing 13C-labeled substrates into microbial biomass and respiratory CO2, approaches that are known to overestimate microbial CUE of native organic matter in soil. Recently, a novel substrate-independent approach based on the measurement of (i) respiration rates and (ii) the incorporation rates of 18O from labelled water into newly formed microbial DNA has been developed in our laboratory for measuring microbial CUE. This approach overcomes the shortcomings of previously used methods and has already been shown to yield realistic estimations of soil microbial CUE. This approach can also be applied to concurrently measure microbial biomass turnover rates, which also influence the sequestration of soil organic C. Microbial turnover rates are also thought to be impacted by environmental factors, but rarely have been directly measured so far. Here, we aimed at determining the short-term effects of environmental factors (soil temperature and soil moisture) on microbial CUE and microbial biomass turnover rates based on the novel 18O approach. Soils from three land-use types (arable

Exploring paraprofessional and classroom factors affecting teacher supervision.

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Irvin, Dwight W; Ingram, Paul; Huffman, Jonathan; Mason, Rose; Wills, Howard

2018-02-01

Paraprofessionals serve a primary role in supporting students with disabilities in the classroom, which necessitates teachers' supervision as a means to improve their practice. Yet, little is known regarding what factors affect teacher supervision. We sought to identify how paraprofessional competence and classroom type affected the levels of teacher direction. We administered an adapted version of the Paraprofessional Needs, Knowledge & Tasks Survey and the Survey for Teachers Supervising Paraprofessionals to teachers supervising paraprofessionals in elementary schools. Structural Equation Modeling was used to examine the link between paraprofessional competence and classroom factors affecting the level of teacher supervision. Our results indicated that when teachers perceived paraprofessionals as being more skilled, they provided more supervision, and when more supervision was provided the less they thought paraprofessionals should be doing their assigned tasks. Additionally, paraprofessionals working in classrooms with more students with mild disabilities received less supervision than paraprofessionals working in classrooms with more students with moderate-to-severe disabilities. Those paraprofessionals in classrooms serving mostly children with mild disabilities were also perceived as having lower levels of skill competence than those serving in classrooms with students with more moderate-to-severe disabilities. By understanding the factors that affect teacher supervision, policy and professional development opportunities can be refined/developed to better support both supervising teachers and paraprofessionals and, in turn, improve the outcomes of children with disabilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Review: Assessing the climate mitigation potential of biomass

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Patrick Moriarty

2016-12-01

Full Text Available For many millennia, humans have used biomass for three broad purposes: food for humans and fodder for farm animals; energy; and materials. Food has always been exclusively produced from biomass, and in the year 1800, biomass still accounted for about 95% of all energy. Biomass has also been a major source of materials for construction, implements, clothing, bedding and other uses, but some researchers think that total human uses of biomass will soon reach limits of sustainability. It is thus important to select those biomass uses that will maximise global climate change benefits. With a ‘food first’ policy, it is increasingly recognised that projections of food needs are important for estimating future global bioenergy potential, and that non-food uses of biomass can be increased by both food crop yield improvements and dietary changes. However, few researchers have explicitly included future biomaterials production as a factor in bioenergy potential. Although biomaterials’ share of the materials market has roughly halved over the past quarter-century, we show that per tonne of biomass, biomaterials will usually allow greater greenhouse gas reductions than directly using biomass for bioenergy. particularly since in many cases, biomaterials can be later burnt for energy after their useful life.

Factors Affecting Customer Retention in the Airline Industry

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Raghda Climis

2017-01-01

Full Text Available Purpose: This study empirically investigated the factors that affect customer retention in the airline industry in North Cyprus. These factors were service quality attributes, perceived safety, customer satisfaction, loyalty reward program, relationship commitment and customer loyalty. The study also investigated four different groups for purposes of travel (business, education, vacation and family visit in the empirical model. Methodology: A descriptive approach was chosen to conduct this research. A quanhip between customer retention and the related study factors; however, not all of these relations are signifcant. The results also showed that the different purposes of travel had different influences on the variables regarding the positive and signifcant relations between them. Some independent variables had a negative effect on the dependent variables. Conclusions: This research was limited to one group and place: the students of Eastern Mediterranean University in North Cyprus. Originality: This study connected the retention, loyalty, satisfaction and service quality factors as attributes. In addition, this research was the frst to include other independent factors affecting satisfaction and loyalty in a comparison between four different groups regarding the purpose of travel in the airline industry.

Factors affecting the effects of diuresis renography

International Nuclear Information System (INIS)

Zhao Deshan

2006-01-01

Diuresis renography is one of the classic methods for diagnosing upper urinary tract obstruction in both children and adults. However, in clinical practice, the results of diuresis renography were often influenced by many factors including diuretics, timing of diuretics injection, the status of renal function and hydration, the volume and compliance of collecting system, bladder fullness and so on. It is important to consider all the factors affecting diuresis renography during performing and interpreting diuresis renography. (authors)

Dynamics of Understory Shrub Biomass in Six Young Plantations of Southern Subtropical China

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Yuanqi Chen

2017-11-01

Full Text Available Understory shrubs are an important component of forest ecosystems and drive ecosystem processes, such as ecosystem carbon cycling. However, shrub biomass carbon stocks have rarely been reported, which limits our understanding of ecosystem C stock and cycling. In this study, we evaluated carbon accumulation of shrub species using allometric equations based on height and basal diameter in six subtropical plantations at the age of 1, 3, 4 and 6 years. The results showed that plantation type did not significantly affect the total biomass of shrubs, but it significantly affected the biomass of Rhodomyrtus tomentosa, Ilex asprella, Clerodendrum fortunatum and Baeckea frutescens. The biomass of dominant shrub species R. tomentosa, I. asprella, Gardenia jasminoides and Melastoma candidum increased with stand age, while the biomass of C. fortunatum and B. frutescens decreased. The inconsistent biomass-time patterns of different shrub species may be the primary reason for the altered total shrub biomass in each plantation. Consequently, we proposed that R. tomentosa, I. asprella, G. jasminoides and M. candidum could be preferable for understory carbon accumulation and should be maintained or planted because of their important functions in carbon accumulation and high economic values in the young plantations of southern subtropical China.

A novel approach of utilization of the fungal conidia biomass to remove heavy metals from the aqueous solution through immobilization

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Cai, Chun-Xiang; Xu, Jian; Deng, Nian-Fang; Dong, Xue-Wei; Tang, Hao; Liang, Yu; Fan, Xian-Wei; Li, You-Zhi

2016-11-01

The biomass of filamentous fungi is an important cost-effective biomass for heavy metal biosorption. However, use of free fungal cells can cause difficulties in the separation of biomass from the effluent. In this study, we immobilized the living conidia of the heavy metal-resistant Penicillium janthinillum strain GXCR by polyvinyl alcohol (PVA)-sodium alginate (SA) beads to remove heavy metals from an aqueous solution containing a low concentration (70 mg/L) of Cu, Pb, and Cd. The PVA-SA-conidia beads showed perfect characters of appropriate mechanical strength suitable for metal removal from the dynamic wastewater environment, an ideal settleability, easy separation from the solution, and a high metal biosorption and removal rate even after four cycles of successive sorption-desorption of the beads, overcoming disadvantages when fungal biomasses alone are used for heavy metal removal from wastewater. We also discuss the major biosorption-affecting factors, biosorption models, and biosorption mechanisms.

Impact of Precipitation Patterns on Biomass and Species Richness of Annuals in a Dry Steppe

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Yan, Hong; Liang, Cunzhu; Li, Zhiyong; Liu, Zhongling; Miao, Bailing; He, Chunguang; Sheng, Lianxi

2015-01-01

Annuals are an important component part of plant communities in arid and semiarid grassland ecosystems. Although it is well known that precipitation has a significant impact on productivity and species richness of community or perennials, nevertheless, due to lack of measurements, especially long-term experiment data, there is little information on how quantity and patterns of precipitation affect similar attributes of annuals. This study addresses this knowledge gap by analyzing how quantity and temporal patterns of precipitation affect aboveground biomass, interannual variation aboveground biomass, relative aboveground biomass, and species richness of annuals using a 29-year dataset from a dry steppe site at the Inner Mongolia Grassland Ecosystem Research Station. Results showed that aboveground biomass and relative aboveground biomass of annuals increased with increasing precipitation. The coefficient of variation in aboveground biomass of annuals decreased significantly with increasing annual and growing-season precipitation. Species richness of annuals increased significantly with increasing annual precipitation and growing-season precipitation. Overall, this study highlights the importance of precipitation for aboveground biomass and species richness of annuals. PMID:25906187

Personal factors affecting organizational commitment of records ...

African Journals Online (AJOL)

This study investigated personal factors affecting organizational commitment among records management personnel in the state universities in Nigeria. Simple cluster sampling with equal allocation method was used to select 180 records management personnel from the study population. A five item organizational ...

Relevant Affect Factors of Smartphone Mobile Data Traffic

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Siniša Husnjak

2016-08-01

Full Text Available Smartphones are used to access a wide range of different information and communication services and perform functions based on data transfer. A number of subscription contracts for smartphones is rapidly increasing, and the development of mobile communications network provides higher speed of data transfer. The continuous increase in the average amount of data traffic per one subscriber contract leads to an increase in the total Mobile Data Traffic (MDT, globally. This research represents a summary of factors that affect the amount of smartphone MDT. Previous literature shows only a few of the factors individually that affect the realization of smartphone MDT. The results of the research clarify the ways which influence the amount of MDT generated by a smartphone. This paper increases the awareness of the users of the methods of generating smartphone MDT. The research also allows users to specify parameters that affect the prediction of generated MDT of a smartphone.

Microbial biomass in faeces of dairy cows affected by a nitrogen deficient diet.

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Jost, Daphne Isabel; Aschemann, Martina; Lebzien, Peter; Joergensen, Rainer Georg; Sundrum, Albert

2013-04-01

Since more than half of the faecal nitrogen (N) originates from microbial N, the objective of the study was to develop a method for quantitatively detecting microbial biomass and portion of living microorganisms in dairy cattle faeces, including bacteria, fungi and archaea. Three techniques were tested: (1) the chloroform fumigation extraction (CFE) method, (2) detection of the fungal cell-membrane component ergosterol and (3) analysis of the cell wall components fungal glucosamine and bacterial muramic acid. In a second step, an N deficient (ND) and an N balanced (NB) diets were compared with respect to the impacts on faecal C and N fractions, microbial indices and digestibility. The mean values of microbial biomass C and N concentrations averaged around 37 and 4.9 mg g(-1) DM, respectively. Ergosterol, together with fungal glucosamine and bacterial muramic acid, revealed a 25% fungal C in relation to the total microbial C content in dairy cattle faeces. Changes in ruminal N supply showed significant effects on faecal composition. Faecal concentrations of NDF, hemicelluloses and undigested dietary N and the total C/N ratio were significantly higher in ND treatment compared to the NB treatment. N deficiency was reflected also by a higher microbial biomass C/N ratio. It was concluded that the assessment of microbial indices provides valuable information with respect to diet effects on faecal composition and the successive decomposition. Further studies should be conducted to explore the potentials for minimising nutrient losses from faeces.

Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland.

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Yufang Shen

Full Text Available Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L. field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer, GMC (gravel mulching with inorganic N fertilizer, FMC (plastic-film mulching with inorganic N fertilizer and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition. The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological

Biomass and nutrient allocation strategies in a desert ecosystem in the Hexi Corridor, northwest China.

Science.gov (United States)

Zhang, Ke; Su, YongZhong; Yang, Rong

2017-07-01

The allocation of biomass and nutrients in plants is a crucial factor in understanding the process of plant structures and dynamics to different environmental conditions. In this study, we present a comprehensive scaling analysis of data from a desert ecosystem to determine biomass and nutrient (carbon (C), nitrogen (N), and phosphorus (P)) allocation strategies of desert plants from 40 sites in the Hexi Corridor. We found that the biomass and levels of C, N, and P storage were higher in shoots than in roots. Roots biomass and nutrient storage were concentrated at a soil depth of 0-30 cm. Scaling relationships of biomass, C storage, and P storage between shoots and roots were isometric, but that of N storage was allometric. Results of a redundancy analysis (RDA) showed that soil nutrient densities were the primary factors influencing biomass and nutrient allocation, accounting for 94.5% of the explained proportion. However, mean annual precipitation was the primary factor influencing the roots biomass/shoots biomass (R/S) ratio. Furthermore, Pearson's correlations and regression analyses demonstrated that although the biomass and nutrients that associated with functional traits primarily depended on soil conditions, mean annual precipitation and mean annual temperature had greater effects on roots biomass and nutrient storage.

The Prospects of Rubberwood Biomass Energy Production in Malaysia

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Jegatheswaran Ratnasingam

2015-03-01

Full Text Available Rubber has been shown to be one of the most important plantation crops in Malaysia, and rubber tree biomass has widespread applications in almost all sectors of the wood products manufacturing sector. Despite its abundance, the exploitation of rubberwood biomass for energy generation is limited when compared to other available biomass such as oil palm, rice husk, cocoa, sugarcane, coconut, and other wood residues. Furthermore, the use of biomass for energy generation is still in its early stages in Malaysia, a nation still highly dependent on fossil fuels for energy production. The constraints for large scale biomass energy production in Malaysia are the lack of financing for such projects, the need for large investments, and the limited research and development activities in the sector of efficient biomass energy production. The relatively low cost of energy in Malaysia, through the provision of subsidy, also restricts the potential utilization of biomass for energy production. In order to fully realize the potential of biomass energy in Malaysia, the environmental cost must be factored into the cost of energy production.

Single-tooth replacement: factors affecting different prosthetic treatment modalities

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Al-Quran Firas A

2011-12-01

Full Text Available Abstract Background The choice between several treatment options for replacing a single missing tooth is influenced by clinical, dentist- and patient-immanent factors. This study aimed to determine the patient factors that would affect the treatment decision to replace a single missing tooth and to assess the satisfaction with several options. Method 200 volunteers involved (121 females and 79 males divided into four groups, Group A: consisted of patients with conventional fixed partial dentures or patients with resin bonded fixed partial dentures. Group B: consisted of patients who received removable partial dentures while Group C: consisted of patients who received a single implant supported crown, and a control group D: consisted of patients who received no treatment. Data were collected using a questionnaire. Results The highest percentage of males within groups (58% was within the removable prostheses category. The majority of the subjects in the study reported that the main reason for replacing a missing tooth was for esthetic and function. Most important factor affecting the choice between treatment modalities was damaging the neighboring teeth. Pain, post operative sensitivity and dental phobia were important factors in choosing the prosthesis type and affected the control group patients not to have any treatment. The highest satisfaction percentage among groups studied was recorded for dental implants then FPD groups, while the least percentage were in both the control and RPD groups, for all aspects of function, esthetic and speech efficiency. Conclusions The final choice between FPD, RPD and implant depended on several factors which affected the decision making; among these is cost and patients' awareness of the different treatment options.

Socio-demographic and clinical factors affecting adherence to ...

African Journals Online (AJOL)

Socio-demographic and clinical factors affecting adherence to antihypertensive medications and blood pressure control among patients attending the family practice clinic in a tertiary hospital in northern Nigeria.

Availability of Dutch biomass for electricity and heat in 2020

International Nuclear Information System (INIS)

Koppejan, J.; Elbersen, W.; Meeusen, M.; Bindraban, P.

2009-11-01

Availability of biomass is an important factor in realizing the Dutch targets for renewable energy. This study maps the availability of Dutch biomass in the framework of alternative applications and sustainability requirements, today and in the future. The conclusion is drawn that there is approximately 13 to 16 million tons of dry biomass available for energy generation in the Netherlands in 2020. This is 30 to 40% of the amount of biomass that is annually used in the Netherlands, generating 53 to 94 PJ of final energy, avoiding 101 to 157 PJ of fossil energy. This availability of biomass and the energy that is generated from the biomass can increase further after 2020. In addition, biomass will also be imported, especially for combustion and co-firing in coal-fired power plants and for the production of transport fuels. [nl

Light intensity as major factor to maximize biomass and lipid productivity of Ettlia sp. in CO2-controlled photoautotrophic chemostat.

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Seo, Seong-Hyun; Ha, Ji-San; Yoo, Chan; Srivastava, Ankita; Ahn, Chi-Yong; Cho, Dae-Hyun; La, Hyun-Joon; Han, Myung-Soo; Oh, Hee-Mock

2017-11-01

The optimal culture conditions are critical factors for high microalgal biomass and lipid productivity. To optimize the photoautotrophic culture conditions, combination of the pH (regulated by CO 2 supply), dilution rate, and light intensity was systematically investigated for Ettlia sp. YC001 cultivation in a chemostat during 143days. The biomass productivity increased with the increase in dilution rate and light intensity, but decreased with increasing pH. The average lipid content was 19.8% and statistically non-variable among the tested conditions. The highest biomass and lipid productivities were 1.48gL -1 d -1 and 291.4mgL -1 d -1 with a pH of 6.5, dilution rate of 0.78d -1 , and light intensity of 1500μmolphotonsm -2 s -1 . With a sufficient supply of CO 2 and nutrients, the light intensity was the main determinant of the photosynthetic rate. Therefore, the surface-to-volume ratio of a photobioreactor should enable efficient light distribution to enhance microalgal growth. Copyright © 2017 Elsevier Ltd. All rights reserved.

Economic Analysis of Factors Affecting Technical Efficiency of ...

African Journals Online (AJOL)

Economic Analysis of Factors Affecting Technical Efficiency of Smallholders ... socio-economic characteristics which influence technical efficiency in maize production. ... Ministry of Agriculture and livestock, records, books, reports and internet.

Biomass torrefaction: A promising pretreatment technology for biomass utilization

Science.gov (United States)

Chen, ZhiWen; Wang, Mingfeng; Ren, Yongzhi; Jiang, Enchen; Jiang, Yang; Li, Weizhen

2018-02-01

Torrefaction is an emerging technology also called mild pyrolysis, which has been explored for the pretreatment of biomass to make the biomass more favorable for further utilization. Dry torrefaction (DT) is a pretreatment of biomass in the absence of oxygen under atmospheric pressure and in a temperature range of 200-300 degrees C, while wet torrrefaction (WT) is a method in hydrothermal or hot and high pressure water at the tempertures within 180-260 degrees C. Torrrefied biomass is hydrophobic, with lower moisture contents, increased energy density and higher heating value, which are more comparable to the characteristics of coal. With the improvement in the properties, torrefied biomass mainly has three potential applications: combustion or co-firing, pelletization and gasification. Generally, the torrefaction technology can accelerate the development of biomass utilization technology and finally realize the maximum applications of biomass energy.

Influential Factors Affecting Materials Management in Construction Projects

Directory of Open Access Journals (Sweden)

Jusoh Zairra Mat

2017-12-01

Full Text Available Construction projects are more often than not plagued by poor performances such as delays, cost overrun, low productivity, construction wastes and compromised quality. Amongst the critical contributory factors of poor project performances, is the ineffectiveness of materials management occurring in the construction sites. Indeed, materials management is a very important component for construction projects. However, there are only limited numbers of research available regarding this topic. Thus, this research focuses its study on materials management, specifically in identifying the influential factors that affect materials management in the construction project activities. Literatures from books, journal articles and conference papers related to poor project performances and materials management have been reviewed. Consequently, this study sorted the salient influential factors and categorized them based on their specific group. Out of 47 factors identified, they are classified into 8 groups. They are (1 site condition; (2 planning and handling on site; (3 management; (4 materials; (5 supplier and manufacturer default; (6 transportation; (7 contractual; and (8 governmental interferences. In conclusion, this study contends that by identifying the influential factors affecting materials management, it will help construction players to avoid the occurrence of those factors and will minimize the negative impacts on the overall performance of construction projects. Hence, the handling-over of project will be according to schedule and not delayed by materials mismanagement.

Empirical Analysis on Factors Affecting User Behavior in Social Commerce

Directory of Open Access Journals (Sweden)

Xu Jiayi

2017-02-01

Full Text Available [Purpose/significance] This paper aims to discover the factors affecting user behavior in the derivative situation of e-commerce, social commerce, and explore the sustainable development and related marketing advice of it. [Method/process］This paper put forward a theoretical model of factors affecting user behavior in social commerce by integrating emotional state impact into the Stimulus-Organism-Response (S-O-R framework. 277 valid samples were collected by questionnaires and PLS. [Result/conclusion］The results show that information quality and tie strength significantly affect user emotional states, while emotional states positively affect user behavior. In addition, graphic features of business information have indirect effects on user emotional states, while it has direct effect on purchase intention.

Short review on the origin and countermeasure of biomass slagging in grate furnace

Directory of Open Access Journals (Sweden)

Yiming eZhu

2014-02-01

Full Text Available Given the increasing demand for energy consumption, biomass has been more and more important as a new type of clean renewable energy source. Biomass direct firing is the most mature and promising utilization method to date, while it allows a timely solution to slagging problems. Alkali metal elements in the biomass fuel and the ash fusion behavior, as the two major origins contributing to slagging during biomass combustion, are analyzed in this paper. The slag presents various layered structures affected by the different compositions of ash particles. Besides, the high-temperature molten material which provides a supporting effect on the skeletal structure in biomass ash was proposed to evaluate the ash fusion characteristics. In addition, numerous solutions to biomass slagging, such as additives, fuel pretreatment and biomass co-firing, were also discussed.

Factors affecting academic leadership in dermatology.

Science.gov (United States)

Martires, Kathryn J; Aquino, Lisa L; Wu, Jashin J

2015-02-01

Although prior studies have examined methods by which to recruit and retain academic dermatologists, few have examined factors that are important for developing academic leaders in dermatology. This study sought to examine characteristics of dermatology residency programs that affect the odds of producing department or division chairs/chiefs and program directors (PDs). Data regarding program size, faculty, grants, alumni residency program attended, lectures, and publications for all accredited US dermatology residency programs were collected. Of the 103 programs examined, 46% had graduated at least 1 chair/chief, and 53% had graduated at least 1 PD. Results emphasize that faculty guidance and research may represent modifiable factors by which a dermatology residency program can increase its graduation of academic leaders.

Potential use of vegetal Biomass as insulation in extreme climates of Ecuador

Directory of Open Access Journals (Sweden)

Luis Velasco Roldan

2015-12-01

Full Text Available In Ecuador, a factor of great ecological wealth is linked to its tradition in the use of fibers and other organic waste composite character as filler element, reinforcement or insulation in the field of housing construction, which carries great potential under the most viable architecture. The climate variability in Ecuador and the low purchasing power of their inhabitants forced to use local available building materials inexpensive or at no cost, in order to achieve economic and comfortable housing. That is why we have analyzed the presence of natural resources and waste biomass confronting regional building tradition, later superimpose geographically with major climatic variables affecting energy efficiency. This makes it possible to determine what, where and how to use the different biomass resources to allow a response to build that has a strong social, economic, environmental and energy argument in order to facilitate the conditions for access to economic habitat efficient, safe and dignified.

How Fencing Affects the Soil Quality and Plant Biomass in the Grassland of the Loess Plateau.

Science.gov (United States)

Zeng, Quanchao; Liu, Yang; Xiao, Li; Huang, Yimei

2017-09-25

Overgrazing is a severe problem in several regions in Northwestern China and has caused serious land degradation. Secondary natural succession plays an important role in the accumulation of soil carbon and nitrogen contents. Estimating the effects of grazing exclusion on soil quality and plant diversity will improve our understanding of the succession process after overgrazing and promote judicious management of degraded pastures. This experiment was designed to measure soil properties and plant diversity following an age chronosequence of grasslands (ages ranged from one year, 12 years, 20 years, and 30 years) in Northwestern China. The results showed that continuous fencing resulted in a considerable increase in plant coverage, plant biomass (above- and below-ground biomass), and plant diversity, which can directly or indirectly improve the accumulation of soil organic carbon and total nitrogen content. The plant coverage and the above- and below-ground biomass linearly increased along the succession time, whereas soil organic C and N contents showed a significant decline in the first 12 years and, subsequently, a significant increase. The increased plant biomass caused an increase in soil organic carbon and soil total nitrogen. These results suggested that soil restoration and plant cover were an incongruous process. Generally, soil restoration is a slow process and falls behind vegetation recovery after grazing exclusion. Although the accumulation of soil C and N stocks needed a long term, vegetation restoration was a considerable option for the degraded grassland due to the significant increase of plant biomass, diversity, and soil C and N stocks. Therefore, fencing with natural succession should be considered in the design of future degraded pastures.

A study of affecting factors on the degree of university students ...

African Journals Online (AJOL)

There are different factors which affect the way people select and continue their attitudes towards products of certain brands. The main objective of the present study was investigating factors affecting the degree of University students' loyalty to Nike brand. This research is functional in regard with objective and ...

78 FR 46418 - Proposed Information Collection (Obligation To Report Factors Affecting Entitlement) Activity...

Science.gov (United States)

2013-07-31

... (Obligation To Report Factors Affecting Entitlement) Activity; Comment Request AGENCY: Veterans Benefits... use of other forms of information technology. Title: Obligation to Report Factors Affecting... entitlement factors. Individual factors such as income, marital status, and the beneficiary's number of...

Analysis of factors affecting employee satisfaction: A case study from Pakistan.

Science.gov (United States)

Rukh, Lala; Choudhary, Muhammad Abbas; Abbasi, Saddam Akber

2015-01-01

Employee job satisfaction has been a research focal point throughout the world. It is a key factor when measuring the performance of an organization and individuals. A leading engineering goods manufacturing enterprise in Pakistan, has been used in this case study. In Pakistan, very limited research has been done with respect to factors affecting job satisfaction. Some research has been done in medical institutions, banks, universities and the information technology sector but large public sector organizations in Pakistan have not been studied. A theoretical foundation for researching factors affecting job satisfaction in large organizations is outlined. The objective of this research is to analyze various demographic, financial and non-financial factors affecting the satisfaction level of employees and to study the effects across different employee groups. This study is based on quantitative data analysis. The employees of the organization under study have been divided into 10 homogeneous groups based on their departments. Information on job related factors (affecting the satisfaction level) have been collected from subsamples of each group using a self-administered questionnaire. An overall sample of 250 (out of total 1100) employees has been selected. Before conducting the survey, reliability of the questionnaire was measured using Cronbach's alpha. The normality of data was also examined using the Kolmogorov Smirnov test. Hypotheses devised to address the research questions were tested by using non-parametric Spearman correlation and Kruskal-Wallis tests. The response rate was 73.2%. Research findings indicated the significant factors that affect the satisfaction level of employees. Median group differences existed between responses based on age, work experience, salary and designation (i.e. job position/rank) of employees. Job satisfaction was also positively and significantly associated with job related factors such as pay, promotion, relation with employees

Factors Affecting Successful Implementation of Hospital Information Systems.

Science.gov (United States)

Farzandipur, Mehrdad; Jeddi, Fatemeh Rangraz; Azimi, Esmaeil

2016-02-01

Today, the use of information systems in health environments, like any other fields, is necessary and organizational managers are convinced to use these systems. However, managers' satisfaction is not the only factor in successfully implementing these systems and failed information technology projects (IT) are reported despite the consent of the directors. Therefore, this study aims to determine the factors affecting the successful implementation of a hospital information system. The study was carried out as a descriptive method in 20 clinical hospitals that the hospital information system (HIS) was conducted in them. The clinical and paraclinical users of mentioned hospitals are the study group. 400 people were chosen as samples in scientific method and the data was collected using a questionnaire consisted of three main human, managerial and organizational, and technological factors, by questionnaire and interview. Then the data was scored in Likert scale (score of 1 to 5) and were analyzed using the SPSS software. About 75 percent of the population were female, with average work experience of 10 years and the mean age was 30 years. The human factors affecting the success of hospital information system implementation achieved the mean score of 3.5, both organizational and managerial factors 2.9 and technological factors the mean of 3. Human factors including computer skills, perceiving usefulness and perceiving the ease of a hospital information system use are more effective on the acceptance and successful implementation of hospital information systems; then the technological factors play a greater role. It is recommended that for the successful implementation of hospital information systems, most of these factors to be considered.

Factors affecting self-regulated learning in medical students: a qualitative study.

Science.gov (United States)

Jouhari, Zahra; Haghani, Fariba; Changiz, Tahereh

2015-01-01

Clinical courses are required of all medical students and means that they must develop the key skill of self-regulation during learning. The ability to self-regulate learning strategies is affected by different factors. This study determined the views of medical students on the factors affecting self-regulated learning (SRL). This study uses a qualitative approach and the content analysis method. Nineteen medical students in their fourth, fifth, and sixth years of study at Isfahan University of Medical Science participated in semi-structured, in-depth interviews. The students were selected using purposive sampling based on their overall grade point average (GPA). Five main themes were found to affect SRL. These themes included family with the two subthemes of family supervisory and supportive roles; peers with the two subthemes of facilitating and inhibiting roles; instructors with the two subthemes of personal and educational instructor's characteristics; educational environment with the two subthemes of facilitator and inhibitor roles; and student with the two subthemes of facilitating and inhibiting personal factors. The outcomes of student understanding of the factors affecting self-regulation indicate that facilitating factors should be used on an individual basis to reduce the effect of inhibiting factors to improve self-regulation in students.

Renewable energy--traditional biomass vs. modern biomass

International Nuclear Information System (INIS)

Goldemberg, Jose; Teixeira Coelho, Suani

2004-01-01

Renewable energy is basic to reduce poverty and to allow sustainable development. However, the concept of renewable energy must be carefully established, particularly in the case of biomass. This paper analyses the sustainability of biomass, comparing the so-called 'traditional' and 'modern' biomass, and discusses the need for statistical information, which will allow the elaboration of scenarios relevant to renewable energy targets in the world

Smoke, Biomass Exposure, and COPD Risk in the Primary Care Setting: The PUMA Study.

Science.gov (United States)

Montes de Oca, Maria; Zabert, Gustavo; Moreno, Dolores; Laucho-Contreras, Maria E; Lopez Varela, Maria Victorina; Surmont, Filip

2017-08-01

The evidence indicates that risk factors other than smoking are important in the development of COPD. It has been postulated that less traditional risk factors (eg, exposure to coal and/or biomass smoke) may interact with smoking to further increase COPD risk. This analysis evaluated the effect of exposure to biomass and smoking on COPD risk in a primary care setting in Latin America. Subjects attending routine primary care visits, ≥40 y old, who were current or former smokers or were exposed to biomass smoke, completed a questionnaire and performed spirometry. COPD was defined as post-bronchodilator FEV 1 /FVC 30), and biomass exposure was defined as an exposure to coal or wood (for heating, cooking, or both) for ≥ 10 y. One thousand seven hundred forty-three individuals completed the questionnaire, and 1,540 performed spirometry. Irrespective of COPD definition, approximately 40% of COPD subjects reported exposure to biomass versus 30% of those without COPD. A higher proportion of COPD subjects (post-bronchodilator FEV 1 /FVC 30 pack-years (66% vs 39%); similar results were found with the lower limit of normal definition. Analysis of exposure to biomass > 10 y plus smoking > 20 pack-years (reference was no exposure) found that tobacco smoking (crude odds ratio [OR] 4.50, 95% CI 2.73-7.41; adjusted OR 3.30, 95% CI 1.93-5.63) and biomass exposure (crude OR 3.66, 95% CI 2.00-6.73; adjusted OR 2.28, 95% CI 1.18-4.41) were risk factors for COPD, with smoking a possible confounder for the association between biomass and COPD (post-bronchodilator FEV 1 /FVC biomass and smoking compared with non-COPD subjects. Smoking and biomass are both risk factors for COPD, but they do not appear to have an additive effect. Copyright © 2017 by Daedalus Enterprises.

Activated carbon from biomass

Science.gov (United States)

Manocha, S.; Manocha, L. M.; Joshi, Parth; Patel, Bhavesh; Dangi, Gaurav; Verma, Narendra

2013-06-01

Activated carbon are unique and versatile adsorbents having extended surface area, micro porous structure, universal adsorption effect, high adsorption capacity and high degree of surface reactivity. Activated carbons are synthesized from variety of materials. Most commonly used on a commercial scale are cellulosic based precursors such as peat, coal, lignite wood and coconut shell. Variation occurs in precursors in terms of structure and carbon content. Coir having very low bulk density and porous structure is found to be one of the valuable raw materials for the production of highly porous activated carbon and other important factor is its high carbon content. Exploration of good low cost and non conventional adsorbent may contribute to the sustainability of the environment and offer promising benefits for the commercial purpose in future. Carbonization of biomass was carried out in a horizontal muffle furnace. Both carbonization and activation were performed in inert nitrogen atmosphere in one step to enhance the surface area and to develop interconnecting porosity. The types of biomass as well as the activation conditions determine the properties and the yield of activated carbon. Activated carbon produced from biomass is cost effective as it is easily available as a waste biomass. Activated carbon produced by combination of chemical and physical activation has higher surface area of 2442 m2/gm compared to that produced by physical activation (1365 m2/gm).

Functional Characterization of NAC and MYB Transcription Factors Involved in Regulation of Biomass Production in Switchgrass (Panicum virgatum.

Directory of Open Access Journals (Sweden)

Ruiqin Zhong

Full Text Available Switchgrass is a promising biofuel feedstock due to its high biomass production and low agronomic input requirements. Because the bulk of switchgrass biomass used for biofuel production is lignocellulosic secondary walls, studies on secondary wall biosynthesis and its transcriptional regulation are imperative for designing strategies for genetic improvement of biomass production in switchgrass. Here, we report the identification and functional characterization of a group of switchgrass transcription factors, including several NACs (PvSWNs and a MYB (PvMYB46A, for their involvement in regulating secondary wall biosynthesis. PvSWNs and PvMYB46A were found to be highly expressed in stems and their expression was closely associated with sclerenchyma cells. Overexpression of PvSWNs and PvMYB46A in Arabidopsis was shown to result in activation of the biosynthetic genes for cellulose, xylan and lignin and ectopic deposition of secondary walls in normally parenchymatous cells. Transactivation and complementation studies demonstrated that PvSWNs were able to activate the SNBE-driven GUS reporter gene and effectively rescue the secondary wall defects in the Arabidopsis snd1 nst1 double mutant, indicating that they are functional orthologs of Arabidopsis SWNs. Furthermore, we showed that PvMYB46A could activate the SMRE-driven GUS reporter gene and complement the Arabidopsis myb46 myb83 double mutant, suggesting that it is a functional ortholog of Arabidopsis MYB46/MYB83. Together, these results indicate that PvSWNs and PvMYB46A are transcriptional switches involved in regulating secondary wall biosynthesis, which provides molecular tools for genetic manipulation of biomass production in switchgrass.

Factors Affecting Furfural as a Nematicide on Turf

OpenAIRE

Luc, J. E.; Crow, W. T.

2013-01-01

Recently a furfural nematicide Multiguard Protect EC was launched for use on turfgrasses in the United States. A series of greenhouse experiments were conducted to determine the concentration and exposure time required for this formulation to irreversibly affect Belonolaimus longicaudatus, and to study factors that might affect the practicality of furfural use in turfgrass systems. One experiment exposed B. longicaudatus to increasing concentrations of furfural (0 to 990 ppm) in vitro for eit...

Emission of toxic air pollutants from biomass combustion

International Nuclear Information System (INIS)

Houck, J.E.; Barnett, S.G.; Roholt, R.B.; Rock, M.E.

1991-01-01

Combustion of biomass for power generation, home heating, process steam generation, and waste disposal constitutes a major source of air pollutants nationwide. Emissions from hog-fueled boilers, demolition wood-fired power plants, municipal waste incinerators, woodstoves, fireplaces, pellet stoves, agricultural burning, and forestry burning have been characterized for a variety of purposes. These have included risk assessment, permitting, emission inventory development, source profiling for receptor modeling, and control technology evaluations. From the results of the source characterization studies a compilation of emission factors for criteria and non-criteria pollutants are presented here. Key among these pollutants are polycyclic aromatic hydrocarbons, priority pollutant metals, carbon monoxide, sulfur dioxide, nitrous oxides, and PM 10 particles. The emission factors from the biomass combustion processes are compared and contrasted with other pollutant sources. In addition, sampling and analysis procedures most appropriate for characterizing emissions from the biomass combustion sources are also discussed

Functional Group Analysis of Biomass Burning Particles Using Infrared Spectroscopy

Science.gov (United States)

Horrell, K.; Lau, A.; Bond, T.; Iraci, L. T.

2008-12-01

Biomass burning is a significant source of particulate organic carbon in the atmosphere. These particles affect the energy balance of the atmosphere directly by absorbing and scattering solar radiation, and indirectly through their ability to act as cloud condensation nuclei (CCN). The chemical composition of biomass burning particles influences their ability to act as CCN, thus understanding the chemistry of these particles is required for understanding their effects on climate and air quality. As climate change influences the frequency and severity of boreal forest fires, the influence of biomass burning aerosols on the atmosphere may become significantly greater. Only a small portion of the organic carbon (OC) fraction of these particles has been identified at the molecular level, although several studies have explored the general chemical classes found in biomass burning smoke. To complement those studies and provide additional information about the reactive functional groups present, we are developing a method for polarity-based separation of compound classes found in the OC fraction, followed by infrared (IR) spectroscopic analysis of each polarity fraction. It is our goal to find a simple, relatively low-tech method which will provide a moderate chemical understanding of the entire suite of compounds present in the OC fraction of biomass burning particles. Here we present preliminary results from pine and oak samples representative of Midwestern United States forests burned at several different temperatures. Wood type and combustion temperature are both seen to affect the composition of the particles. The latter seems to affect relative contributions of certain functional groups, while oak demonstrates at least one additional chemical class of compounds, particularly at lower burning temperatures, where gradual solid-gas phase reactions can produce relatively large amounts of incompletely oxidized products.

Identification and characterisation of factors affecting losses in the large-scale, non-ventilated bulk storage of wood chips and development of best storage practices

Energy Technology Data Exchange (ETDEWEB)

Garstang, J.; Weekes, A.; Poulter, R.; Bartlett, D.

2002-07-01

The report describes the findings of a study to determine the factors affecting the commercial storage of wood chips for biomass power generation in the UK. The UK's first such plant in North Yorkshire uses a mixture of forestry residues and short rotation coppice (SRC) willow, where problems with the stored fuel highlighted the need to determine best storage practices. Two wood chip piles were built (one with willow chip and the other with wood chips from board leaf forestry residues) and monitored (moisture, temperature, chemical composition, spore numbers and species, heat and air flows, bulk density, etc). Local weather data was also obtained. Recommendations for future storage practices are made.

A Study of Some Parameters Affecting the Bio sorption of "1"3"7 Cs Radionuclide by Non Living Biomass

International Nuclear Information System (INIS)

Abu-Khadra, S.A.; Abdelmalik, W.E.Y.; Elrafie, M.; Killa, H.M.

2016-01-01

In this paper, the bio sorption process of "1"3"7 Cs using three types of non living biomass namely; ( waste tea leaves, peanut shell and waste sugarcane bagasse) was investigated in a batch technique. The effect of some parameters e .g. heating, biomass weight, contact time, carrier concentration and solution ph on the bio sorption of "1"3"7Cs by the three chosen bio masses was studied. Heating the biomass samples to 250 degree C showed the highest uptake percentage of Cs. The uptake percentage increased as the biomass weight increased. Increasing the carrier concentration from 10-7-10-4 M/L, increased the bio sorbed amount of Cs (mg/g). Increasing the solution ph, from 3 to 9 showed an insignificant effect on the uptake percentage. The sorption data have been interpreted in terms of Langmuir and Freundlich isotherms. The results of the present study suggest that these kinds of non living biomass can be used beneficially for cesium removal from aqueous solution

Nitrogen-to-Protein Conversion Factors for Crop Residues and Animal Manure Common in China.

Science.gov (United States)

Chen, Xueli; Zhao, Guanglu; Zhang, Yang; Han, Lujia; Xiao, Weihua

2017-10-25

Accurately determining protein content is essential in exploiting biomass as feed and fuel. A survey of biomass samples in China indicated protein contents from 2.65 to 3.98% for crop residues and from 6.07 to 10.24% for animal manure of dry basis. Conversion factors based on amino acid nitrogen (k A ) ranged from 5.42 to 6.00 for the former and from 4.78 to 5.36 for the latter, indicating that the traditional factor of 6.25 is not suitable for biomass samples. On the other hand, conversion factors from Kjeldahl nitrogen (k P ) ranged from 3.97 to 4.57 and from 2.76 to 4.31 for crop residues and animal manure, respectively. Of note, conversion factors were strongly affected by amino acid composition and levels of nonprotein nitrogen. Thus, k P values of 4.23 for crop residues, 4.11 for livestock manure, and 3.11 for poultry manure are recommended to better estimate protein content from total nitrogen.

Differences in Cellulosic Supramolecular Structure of Compositionally Similar Rice Straw Affect Biomass Metabolism by Paddy Soil Microbiota.

Directory of Open Access Journals (Sweden)

Tatsuki Ogura

Full Text Available Because they are strong and stable, lignocellulosic supramolecular structures in plant cell walls are resistant to decomposition. However, they can be degraded and recycled by soil microbiota. Little is known about the biomass degradation profiles of complex microbiota based on differences in cellulosic supramolecular structures without compositional variations. Here, we characterized and evaluated the cellulosic supramolecular structures and composition of rice straw biomass processed under different milling conditions. We used a range of techniques including solid- and solution-state nuclear magnetic resonance (NMR and Fourier transform infrared spectroscopy followed by thermodynamic and microbial degradability characterization using thermogravimetric analysis, solution-state NMR, and denaturing gradient gel electrophoresis. These measured data were further analyzed using an "ECOMICS" web-based toolkit. From the results, we found that physical pretreatment of rice straw alters the lignocellulosic supramolecular structure by cleaving significant molecular lignocellulose bonds. The transformation from crystalline to amorphous cellulose shifted the thermal degradation profiles to lower temperatures. In addition, pretreated rice straw samples developed different microbiota profiles with different metabolic dynamics during the biomass degradation process. This is the first report to comprehensively characterize the structure, composition, and thermal degradation and microbiota profiles using the ECOMICS toolkit. By revealing differences between lignocellulosic supramolecular structures of biomass processed under different milling conditions, our analysis revealed how the characteristic compositions of microbiota profiles develop in addition to their metabolic profiles and dynamics during biomass degradation.

Factors that affect South African Reading Literacy Achievement ...

African Journals Online (AJOL)

Factors that affect South African Reading Literacy Achievement: evidence from prePIRLS 2011. ... achievement among Grade 4 learners in South Africa by utilising aspects of Carroll's model of school learning. ... AJOL African Journals Online.

Field emissions of N2O during biomass production may affect the sustainability of agro-biofuels

DEFF Research Database (Denmark)

Carter, Mette Sustmann; Hauggaard-Nielsen, Henrik; Heiske, Stefan

relate measured field emissions of N2O to the reduction in fossil fuel‐derived CO2, which is obtained when agricultural biomasses are used for biofuel production. The analysis includes five organically managed crops (viz. maize, rye, rye‐vetch, vetch and grass‐clover) and three scenarios for conversion...... of biomass to biofuel. The scenarios are 1) bioethanol, 2) biogas and 3) co‐production of bioethanol and biogas. In scenarios 3, the biomass is first used for bioethanol fermentation and subsequently the residue from this process is utilized for biogas production. The net reduction in greenhouse gas...... emissions is calculated as the avoided fossil fuel‐derived CO2, where the N2O emission has been subtracted. This value does not account for CO2 emissions from farm machinery and during biofuel production. We obtained the greatest net reduction in greenhouse gas emissions by co‐production of bioethanol...

Biomass, new markets ! How to mobilize the resource? Seminar proceedings

International Nuclear Information System (INIS)

2005-10-01

The various papers of this seminar addressed the following questions: how to valorize the biomass potential to respond to challenges of greenhouse gas emission reduction? What are the conditions to mobilize biomass considering the existing concurrence between its different usages? How to use experiences of biomass mobilization to cope with the demand increase? How to consider the key factors of success all together? More particularly, the interveners addressed the different resources (agricultural by-products, forestry, and wood waste), actors, technical approaches, and economical and logistical aspects, the role of biomass in the commitments for the struggle against climate change, the issue of supply

Effect of diverse ecological conditions on biomass production of ...

African Journals Online (AJOL)

Kangaroo grass native to Australia is known as the best grass to grow on different environmental and soil conditions. Biomass production of any grass is the key factor to estimate that if the grass could fulfill the animal requirements. Biomass production of kangaroo grass was estimated in this study at three growth stages on ...

Demographic controls of aboveground forest biomass across North America.

Science.gov (United States)

Vanderwel, Mark C; Zeng, Hongcheng; Caspersen, John P; Kunstler, Georges; Lichstein, Jeremy W

2016-04-01

Ecologists have limited understanding of how geographic variation in forest biomass arises from differences in growth and mortality at continental to global scales. Using forest inventories from across North America, we partitioned continental-scale variation in biomass growth and mortality rates of 49 tree species groups into (1) species-independent spatial effects and (2) inherent differences in demographic performance among species. Spatial factors that were separable from species composition explained 83% and 51% of the respective variation in growth and mortality. Moderate additional variation in mortality (26%) was attributable to differences in species composition. Age-dependent biomass models showed that variation in forest biomass can be explained primarily by spatial gradients in growth that were unrelated to species composition. Species-dependent patterns of mortality explained additional variation in biomass, with forests supporting less biomass when dominated by species that are highly susceptible to competition (e.g. Populus spp.) or to biotic disturbances (e.g. Abies balsamea). © 2016 John Wiley & Sons Ltd/CNRS.

Feedstock quality : an important consideration in forest biomass supply

Energy Technology Data Exchange (ETDEWEB)

Ryans, M. [FP Innovations, Vancouver, BC (Canada). FERIC

2009-07-01

The move to forest-based sources of biomass requires an emphasis on the quality of forest residues. Customers set the feedstock requirements, and demand homogeneous and predictable quality. The top quality factors are appropriate moisture content, consistent particle size, chlorine content, and clean material. The seasonal variability of the resource means that suppliers must determine how to deliver a year-round supply with appropriate moisture content. Methods such as pre-piling and covering with a tarp are being tested. Although mills tailored for biomass deliveries have modernized boilers capable of burning a variety of biomass feedstocks at varying moisture contents, a 10 per cent reduction in moisture content can offer a good return on investment because suppliers could transports more energy content and less water per tonne of biomass. This presentation also discussed the range of equipment choices available for delivering the right-sized biomass, and outlined the right and wrong practices that influence biomass quality along the supply chain. figs.

Economics of multifunctional biomass systems

International Nuclear Information System (INIS)

Ignaciuk, A.

2006-01-01

Chapter 2 focuses on the competition between traditional agricultural production and growing demand for biomass plantations. The aim of this chapter is to investigate the effects of various energy policies, aimed at both reducing the emissions of greenhouse gases (GHG) and increasing the share of bioelectricity, on the production of biomass and agricultural commodities. A partial equilibrium model is developed to illustrate some of the potential impacts of these policies on greenhouse gas emissions, land reallocation and prices of food and electricity. A partial framework is used, because it provides a transparent and consistent structure and enables to concentrate on only the relevant economic sectors (agriculture, biomass, conventional electricity, and bioelectricity). In the model, GHG emissions depend on land use patterns and fossil fuel use. The innovative element of this model is that it integrates two distinct analyses, namely an analysis of substitution mechanisms between energy from biomass and from fossil fuels, and an analysis of the effects of changes in demand for biomass on land use and GHG emissions. Chapter 3 deals with the impact of climate policies on land use and land cover change and possible impacts on reestablishment of semi-natural areas, mainly forestry and willow plantations. The aim of this chapter is to investigate the impact of climate policies to reduce greenhouse gas emissions by means of promoting biomass and bioelectricity. In this context, the analysis is performed on how these policies might affect production of agricultural commodities and trade patterns of biomass and bioelectricity. To this purpose, an applied general equilibrium model (AGE) is developed with special attention to biomass and agricultural crops for a small open economy, with an Armington specification for international trade. Chapter 4 focuses on the multiproductivity issues of agriculture, biomass, and forestry sectors resulting in additional production inputs

Motivation factors affecting employees job performance in selected ...

African Journals Online (AJOL)

Motivation can be intrinsic, such as satisfaction and feelings of achievement; or extrinsic, such as rewards, punishment, and goal obtainment. The study assessed the motivating factors affecting the job performance of two oil palm companies' ...

Bio energy: Production of Biomass; Produksjon av biomasse

Energy Technology Data Exchange (ETDEWEB)

Noreng, Katrina; Indergaard, Mentz; Liodden, Ole Joergen; Hohle, Erik Eid; Sandberg, Eiliv

2001-07-01

This is Chapter 2 of the book ''Bio energy - Environment, technique and market''. Its main sections are: (1) Biomass resources in Norway, (2) The foundation - photosynthesis, (3) Biomass from forestry, (4) Biomass from peat lands, (5) Biomass from agriculture and (6) Biomass from lakes and sea. The exposition largely describes the conditions in Norway, where the use of bio energy can be increased from 15 TWh to 35 TWh using available technology. At present, water-borne heating systems are not extensively used in Norway and 30% of the biomass that is cut in the forests remains there as waste. Using this waste for energy generation would not only contribute to reduce the emission of greenhouse gases, but would often lead to improved forest rejuvenation. Use of a few per thousand of the Norwegian peat lands would produce 2 - 3 TWh. According to calculations, along the coast of Norway, there are at least 15 mill tonnes of kelp and sea tangle and these resources can be utilized in a sustainable way.

INTERNATIONAL DIFFERENCES IN FACTORS AFFECTING LABOUR MOBILITY.

Science.gov (United States)

SELLIER, F.; ZARKA, C.

THE GEOGRAPHICAL, OCCUPATIONAL, AND INTERFIRM MOBILITY, AND THE FACTORS AFFECTING THESE MOVEMENTS FOR WORKERS IN FRANCE, ITALY, GERMANY, AND SWEDEN IN THE PERIOD SINCE THE SECOND WORLD WAR ARE STUDIED. DATA OBTAINED FROM INDUSTRIAL SURVEYS AND GENERAL CENSUSES WERE USED TO COMPARE THE FOUR COUNTRIES WITH EACH OTHER AND WITH THE UNITED STATES.…

Biomass energy conversion: conventional and advanced technologies

Energy Technology Data Exchange (ETDEWEB)

Young, B C; Hauserman, W B [Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND (United States)

1995-12-01

planned projects worldwide. The main incentives, such as greenhouse gas reduction, the expanded use of various biomass sources and improved efficiency, are often insufficient to overcome barriers to the development and commercialization of advanced conversion systems and even to the introduction of conventional biomass-fired combustors for heat and power. Site characteristics, handling and transport costs and the availability and reliability of fuel feedstocks are major considerations in selecting system designs. In transferring biomass conversion technology to developing countries, these factors and others, such as sufficient data on the composition of the indigenous biomass, economics and training, are important. Successful transfer, however, will depend on a facilitator from the developing country and a technology champion from the developed country. (author) 36 refs, 4 figs, 2 tabs

Biomass energy conversion: conventional and advanced technologies

International Nuclear Information System (INIS)

Young, B.C.; Hauserman, W.B.

1995-01-01

planned projects worldwide. The main incentives, such as greenhouse gas reduction, the expanded use of various biomass sources and improved efficiency, are often insufficient to overcome barriers to the development and commercialization of advanced conversion systems and even to the introduction of conventional biomass-fired combustors for heat and power. Site characteristics, handling and transport costs and the availability and reliability of fuel feedstocks are major considerations in selecting system designs. In transferring biomass conversion technology to developing countries, these factors and others, such as sufficient data on the composition of the indigenous biomass, economics and training, are important. Successful transfer, however, will depend on a facilitator from the developing country and a technology champion from the developed country. (author)

Thermogravimetric study on the influence of structural, textural and chemical properties of biomass chars on CO2 gasification reactivity

International Nuclear Information System (INIS)

Bouraoui, Zeineb; Jeguirim, Mejdi; Guizani, Chamseddine; Limousy, Lionel; Dupont, Capucine; Gadiou, Roger

2015-01-01

The present investigation aims to examine the influence of textural, structural and chemical properties of biomass chars on the CO 2 gasification rate. Various lignocellulosic biomass chars were prepared under the same conditions. Different analytical techniques were used to determine the char properties such as Scanning Electronic Microscopy, nitrogen adsorption manometry, Raman spectroscopy and X Ray Fluorescence. Gasification tests were carried out in a thermobalance under 20% CO 2 in nitrogen at 800 °C. Significant differences of the total average reactivity were observed with a factor of 2 between the prepared chars. Moreover, different behaviors of gasification rate profiles versus conversion were obtained. This difference of behavior appeared to be correlated with the biomass char properties. Hence, up to 70% of conversion, the gasification rate was shown to depend on the char external surface and the potassium content. At higher conversion ratio, a satisfactory correlation between the Catalytic Index and the average gasification rate was identified. The results highlight the importance of knowing both textural and structural properties and mineral contents of biomass chars to predict fuel reactivity during CO 2 gasification processes. Such behavior prediction is highly important in the gasifiers design for char conversion. - Highlights: • CO 2 gasification reactivity of various lignocellulosic chars were examined. • Chars properties affect strongly samples gasification behavior. • Initial gasification rate is affected by external surface, K content and D3/G ratio. • Gasification rate behavior depends on the Alkali index at high conversion

Factors Which Affect Academic Achievement of University Students

OpenAIRE

RENÇBER, Bahman Alp

2012-01-01

The purpose of this study is to investigate by analysing factors affecting academic achievement of university students. Also effects of these factors are studied. For this purpose, the students attending “Statistics and Transport Technology” course at Gazi University, Industrial Arts Education and Arts Faculty, Industrial Technology Education Department, in the 2008-2009 academic year have been identified as the study universe. Analysis has been done by taking examples for this universe. The ...

Biomass recalcitrance

DEFF Research Database (Denmark)

Felby, Claus

2009-01-01

Alternative and renewable fuels derived from lignocellulosic biomass offer a promising alternative to conventional energy sources, and provide energy security, economic growth, and environmental benefits. However, plant cell walls naturally resist decomposition from microbes and enzymes - this co......Alternative and renewable fuels derived from lignocellulosic biomass offer a promising alternative to conventional energy sources, and provide energy security, economic growth, and environmental benefits. However, plant cell walls naturally resist decomposition from microbes and enzymes...... - this collective resistance is known as "biomass recalcitrance." Breakthrough technologies are needed to overcome barriers to developing cost-effective processes for converting biomass to fuels and chemicals. This book examines the connection between biomass structure, ultrastructure, and composition......, to resistance to enzymatic deconstruction, with the aim of discovering new cost-effective technologies for biorefineries. It contains chapters on topics extending from the highest levels of biorefinery design and biomass life-cycle analysis, to detailed aspects of plant cell wall structure, chemical treatments...

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

Science.gov (United States)

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

2017-01-01

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

Biomass expansion factors of Olea ferruginea (Royle) in sub tropical ...

African Journals Online (AJOL)

Wood biomass gives information about total productivity of the forest as well as individual tree. Olea ferruginea (Royle) which is small and evergreen is widely distributed in native sub tropical forests of Pakistan and extensively used as fuelwood domestically. This study was carried out in the sub tropical forests of Pakistan at ...

Major Biomass Conference

Science.gov (United States)

Top Scientists, Industry and Government Leaders to Gather for Major Biomass Conference America, South America and Europe will focus on building a sustainable, profitable biomass business at the Third Biomass Conference of the Americas in Montreal. Scheduled presentations will cover all biomass

Biomass power. Exploring the diffusion challenges in Spain

International Nuclear Information System (INIS)

Dinica, Valentina

2009-01-01

The use of biomass resources for power generation offers numerous benefits of interest for political decision-makers: fuel security, rural and industrial development, ecological benefits. In Spain, policy instruments have been used since 1980 to stimulate biomass power generation. However, the diffusion outcome by 2007 was very disappointing: only 525 MW. This paper argues that two factors lie at the core of this: the conceptualization of biomass resources by political decision-makers in the instruments used, and the desire that policy instruments be in line with market liberalization principles. These generated a persistent economic obstacle for biomass power generation, and impeded the development of markets for the supply of biomass resources. The policy learning regarding the heterogeneity of biomass resources, and the investors' expectations on risks, profitability and resource markets was very slow among political decision-makers. The paper contributes to the understanding of diffusion outcomes by proposing to analyse diffusion by means of five indicators: types of resources, technologies, developers, motivations to invest and project sizes. Besides, the paper shows the usefulness of investigating policy instruments in terms of their risk and profitability characteristics. This enables a better understanding of the diffusion patterns and outcomes. (author)

Characterization and comparison of biomass produced from various sources: Suggestions for selection of pretreatment technologies in biomass-to-energy

International Nuclear Information System (INIS)

Chiang, Kung-Yuh; Chien, Kuang-Li; Lu, Cheng-Han

2012-01-01

Highlights: ► Biomass with higher volatile matter content has a higher carbon conversion rate. ► Applying the suitable pretreatment techniques that will enhance the bioenergy yield. ► The ratio of H 2 O/fixed carbon is a critical factor for enhancing the energy conversion. -- Abstract: This study investigated the characteristics of 26 varieties of biomass produced from forestry, agriculture, municipality, and industry in Taiwan to test their applicability in thermal conversion technologies and evaluation of enhanced energy efficiency. Understanding the reactivity of the tested biomass, the cluster analysis was also used in this research to classify into characteristics groups of biomass. This research also evaluated the feasibility of energy application of tested biomass by comparing it to the physicochemical properties of various coals used in Taiwan’s power plants. The experimental results indicated that the volatile matter content of the all tested biomass was 60% and above. It can be concluded that the higher carbon conversion rate will occur in the thermal conversion process of all tested biomass. Based on the results of lower heating value (LHV) of MSW and non-hazardous industrial sludge, the LHV was lower than other tested biomass that was between 1000 and 1800 kcal/kg. This is due to the higher moisture content of MSW and sludge that resulted in the lower LHV. Besides, the LHV of other tested biomass and their derived fuels was similar to the tested coal. However, the energy densities of woody and agricultural waste were smaller than that of the coal because the bulky densities of woody and agricultural wastes were low. That is, the energy utilization efficiency of woody and agricultural waste was relatively low. To improve the energy density of tested biomass, appropriate pre-treatment technologies, such as shredding, pelletizing or torrefied technologies can be applied, that will enhance the energy utilization efficiency of all tested biomass.

The seeding and cultivation of a tropical species of filamentous Ulva for algal biomass production.

Directory of Open Access Journals (Sweden)

Christina Carl

Full Text Available Filamentous species of Ulva are ideal for cultivation because they are robust with high growth rates and maintained across a broad range of environments. Temperate species of filamentous Ulva are commercially cultivated on nets which can be artificially 'seeded' under controlled conditions allowing for a high level of control over seeding density and consequently biomass production. This study quantified for the first time the seeding and culture cycle of a tropical species of filamentous Ulva (Ulva sp. 3 and identified seeding density and nursery period as key factors affecting growth and biomass yield. A seeding density of 621,000 swarmers m(-1 rope in combination with a nursery period of five days resulted in the highest growth rate and correspondingly the highest biomass yield. A nursery period of five days was optimal with up to six times the biomass yield compared to ropes under either shorter or longer nursery periods. These combined parameters of seeding density and nursery period resulted in a specific growth rate of more than 65% day(-1 between 7 and 10 days of outdoor cultivation post-nursery. This was followed by a decrease in growth through to 25 days. This study also demonstrated that the timing of harvest is critical as the maximum biomass yield of 23.0 ± 8.8 g dry weight m(-1 (228.7 ± 115.4 g fresh weight m(-1 was achieved after 13 days of outdoor cultivation whereas biomass degraded to 15.5 ± 7.3 g dry weight m(-1 (120.2 ± 71.8 g fresh weight m(-1 over a longer outdoor cultivation period of 25 days. Artificially seeded ropes of Ulva with high biomass yields over short culture cycles may therefore be an alternative to unattached cultivation in integrated pond-based aquaculture systems.

Relationships between biomass composition and liquid products formed via pyrolysis

Directory of Open Access Journals (Sweden)

Fan eLin

2015-10-01

Full Text Available Thermal conversion of biomass is a rapid, low-cost way to produce a dense liquid product, known as bio-oil, that can be refined to transportation fuels. However, utilization of bio-oil is challenging due to its chemical complexity, acidity, and instability—all results of the intricate nature of biomass. A clear understanding of how biomass properties impact yield and composition of thermal products will provide guidance to optimize both biomass and conditions for thermal conversion. To aid elucidation of these associations, we first describe biomass polymers, including phenolics, polysaccharides, acetyl groups, and inorganic ions, and the chemical interactions among them. We then discuss evidence for three roles (i.e., models for biomass components in formation of liquid pyrolysis products: (1 as direct sources, (2 as catalysts, and (3 as indirect factors whereby chemical interactions among components and/or cell wall structural features impact thermal conversion products. We highlight associations that might be utilized to optimize biomass content prior to pyrolysis, though a more detailed characterization is required to understand indirect effects. In combination with high-throughput biomass characterization techniques this knowledge will enable identification of biomass particularly suited for biofuel production and can also guide genetic engineering of bioenergy crops to improve biomass features.

Relationships between Biomass Composition and Liquid Products Formed via Pyrolysis

International Nuclear Information System (INIS)

Lin, Fan; Waters, Christopher L.; Mallinson, Richard G.; Lobban, Lance L.; Bartley, Laura E.

2015-01-01

Thermal conversion of biomass is a rapid, low-cost way to produce a dense liquid product, known as bio-oil, that can be refined to transportation fuels. However, utilization of bio-oil is challenging due to its chemical complexity, acidity, and instability – all results of the intricate nature of biomass. A clear understanding of how biomass properties impact yield and composition of thermal products will provide guidance to optimize both biomass and conditions for thermal conversion. To aid elucidation of these associations, we first describe biomass polymers, including phenolics, polysaccharides, acetyl groups, and inorganic ions, and the chemical interactions among them. We then discuss evidence for three roles (i.e., models) for biomass components in the formation of liquid pyrolysis products: (1) as direct sources, (2) as catalysts, and (3) as indirect factors whereby chemical interactions among components and/or cell wall structural features impact thermal conversion products. We highlight associations that might be utilized to optimize biomass content prior to pyrolysis, though a more detailed characterization is required to understand indirect effects. In combination with high-throughput biomass characterization techniques, this knowledge will enable identification of biomass particularly suited for biofuel production and can also guide genetic engineering of bioenergy crops to improve biomass features.

Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter.

Science.gov (United States)

Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Hammelehle, Andreas; Mayer, Jochen

2017-01-01

Root biomass is one of the most relevant root parameters for studies of plant response to environmental change, soil carbon modeling or estimations of soil carbon sequestration. A major source of error in root biomass quantification of agricultural crops in the field is the presence of extraneous organic matter in soil: dead roots from previous crops, weed roots, incorporated above ground plant residues and organic soil amendments, or remnants of soil fauna. Using the isotopic difference between recent maize root biomass and predominantly C3-derived extraneous organic matter, we determined the proportions of maize root biomass carbon of total carbon in root samples from the Swiss long-term field trial "DOK." We additionally evaluated the effects of agricultural management (bio-organic and conventional), sampling depth (0-0.25, 0.25-0.5, 0.5-0.75 m) and position (within and between maize rows), and root size class (coarse and fine roots) as defined by sieve mesh size (2 and 0.5 mm) on those proportions, and quantified the success rate of manual exclusion of extraneous organic matter from root samples. Only 60% of the root mass that we retrieved from field soil cores was actual maize root biomass from the current season. While the proportions of maize root biomass carbon were not affected by agricultural management, they increased consistently with soil depth, were higher within than between maize rows, and were higher in coarse (>2 mm) than in fine (≤2 and >0.5) root samples. The success rate of manual exclusion of extraneous organic matter from root samples was related to agricultural management and, at best, about 60%. We assume that the composition of extraneous organic matter is strongly influenced by agricultural management and soil depth and governs the effect size of the investigated factors. Extraneous organic matter may result in severe overestimation of recovered root biomass and has, therefore, large implications for soil carbon modeling and estimations

Biomass treatment method

Science.gov (United States)

Friend, Julie; Elander, Richard T.; Tucker, III; Melvin P.; Lyons, Robert C.

2010-10-26

A method for treating biomass was developed that uses an apparatus which moves a biomass and dilute aqueous ammonia mixture through reaction chambers without compaction. The apparatus moves the biomass using a non-compressing piston. The resulting treated biomass is saccharified to produce fermentable sugars.

Biodiversity enhances reef fish biomass and resistance to climate change.

Science.gov (United States)

Duffy, J Emmett; Lefcheck, Jonathan S; Stuart-Smith, Rick D; Navarrete, Sergio A; Edgar, Graham J

2016-05-31

Fishes are the most diverse group of vertebrates, play key functional roles in aquatic ecosystems, and provide protein for a billion people, especially in the developing world. Those functions are compromised by mounting pressures on marine biodiversity and ecosystems. Because of its economic and food value, fish biomass production provides an unusually direct link from biodiversity to critical ecosystem services. We used the Reef Life Survey's global database of 4,556 standardized fish surveys to test the importance of biodiversity to fish production relative to 25 environmental drivers. Temperature, biodiversity, and human influence together explained 47% of the global variation in reef fish biomass among sites. Fish species richness and functional diversity were among the strongest predictors of fish biomass, particularly for the large-bodied species and carnivores preferred by fishers, and these biodiversity effects were robust to potentially confounding influences of sample abundance, scale, and environmental correlations. Warmer temperatures increased biomass directly, presumably by raising metabolism, and indirectly by increasing diversity, whereas temperature variability reduced biomass. Importantly, diversity and climate interact, with biomass of diverse communities less affected by rising and variable temperatures than species-poor communities. Biodiversity thus buffers global fish biomass from climate change, and conservation of marine biodiversity can stabilize fish production in a changing ocean.

Analysis of the factors that affect photon counts in Compton scattering

International Nuclear Information System (INIS)

Luo, Guang; Xiao, Guangyu

2015-01-01

Compton scattering has been applied in a variety of fields. The factors that affect Compton scattering have been studied extensively in the literature. However, the factors that affect the measured photon counts in Compton scattering are rarely considered. In this paper, we make a detailed discussion on those factors. First, Compton scattering experiments of some alloy series and powder mixture series are explored. Second, the electron density is researched in terms of atom and lattice constants. Third, the factor of attenuation coefficient is discussed. And then, the active degree of electrons is discussed based on the DFT theory. Lastly, the conclusions are made, that the factors affecting Compton scattering photon counts include mainly electron number density, attenuation coefficient and active degree of electrons. - Highlights: • Compton scattering experiments of some alloy series and powder mixture series are explored. • The influence of electron density is researched in terms of atom and lattice constants. • The influence of attenuation coefficient is discussed. • The active degree of electrons is discussed detailedly based on DFT theory

How important is biomass burning in Canada to mercury contamination?

Science.gov (United States)

Fraser, Annemarie; Dastoor, Ashu; Ryjkov, Andrei

2018-05-01

Wildfire frequency has increased in past four decades in Canada and is expected to increase in future as a result of climate change (Wotton et al., 2010). Mercury (Hg) emissions from biomass burning are known to be significant; however, the impact of biomass burning on air concentration and deposition fluxes in Canada has not been previously quantified. We use estimates of burned biomass from FINN (Fire INventory from NCAR) and vegetation-specific emission factors (EFs) of mercury to investigate the spatiotemporal variability of Hg emissions in Canada. We use Environment and Climate Change Canada's GEM-MACH-Hg (Global Environmental Multi-scale, Modelling Air quality and Chemistry model, mercury version) to quantify the impact of biomass burning in Canada on spatiotemporal variability of air concentrations and deposition fluxes of mercury in Canada. We use North American gaseous elemental mercury (GEM) observations (2010-2015), GEM-MACH-Hg, and an inversion technique to optimize the EFs for GEM for five vegetation types represented in North American fires to constrain the biomass burning impacts of mercury. The inversion results suggest that EFs representing more vegetation types - specifically peatland - are required. This is currently limited by the sparseness of measurements of Hg from biomass burning plumes. More measurements of Hg concentration in the air, specifically downwind of fires, would improve the inversions. We use three biomass burning Hg emissions scenarios in Canada to conduct three sets of model simulations for 2010-2015: two scenarios where Hg is emitted only as GEM using literature or optimized EFs and a third scenario where Hg is emitted as GEM using literature EFs and particle bound mercury (PBM) emitted using the average GEM/PBM ratio from lab measurements. The three biomass burning emission scenarios represent a range of possible values for the impacts of Hg emissions from biomass burning in Canada on Hg concentration and deposition. We find

Critical success factors for biomass. Identification/specification of critical success factors in the development and market introduction of biomass conversion systems for the production of electricity and/or heat and/or gaseous/liquid secondary energy carriers

International Nuclear Information System (INIS)

Van Ree, R.; Dinkelbach, L.; Van Doorn, J.; Hemmes, K.; Gerlagh, T.; Groenendaal, B.

2000-06-01

The Dutch government has set the policy target that in 2020 10% of the total energy consumption has to be provided by means of renewable energy sources. Biomass is expected to play a major role (25-30%) in this future renewable energy based energy supply system. However, it is still unclear if this biomass-based target will be reached. Although studies showed that success or failure of innovations and projects depend on a multitude of scientific, technical, economic and societal variables, a number of questions still remained unanswered. This information often concentrated exclusively on the cost price aspects. This study is conducted to identify the internal and external barriers or constraints other than cost aspects, which are of vital importance to a successful penetration of biomass in the Dutch energy market. Barriers with a decreasing influence on the market introduction of bioenergy in the Netherlands are: short-term contractability of biomass (organic waste streams) for energy purposes, applicable emission and waste policies, and unfamiliarity of bioenergy by the public and government. Barriers that potentially could play an important role on the market introduction of bioenergy in the Netherlands in the near future are: long-term contractability of biomass (organic waste streams and energy crops) for energy purposes, the 'new' emission constraints and their potential negative influence on the implementation of small-scale biomass-based combined-cycle plants, the rivalry of bioenergy with other renewable energy based technologies in a liberalising energy market, the social acceptance of bioenergy, the future European agriculture policy (energy crops), and the current status and development perspectives of biomass-based energy conversion technologies. 66 refs

Feasibility of Biomass Biodrying for Gasification Process

Science.gov (United States)

Hamidian, Arash

An important challenge of biomass gasification is the limitation of feedstock quality especially the moisture content, which plays a significant role on the performance of gasification process. Gasification requires low moisture levels (20% and less) and several reports have emphasized on the moisture as a typical problem while gasifying biomass. Moisture affects overall reaction rates in the gasifiers as a result of temperature drop and ultimately increases tar content, decreases gas yield, changes the composition of produced gas and affects the efficiency. Therefore, it is mandatory to pre-treat the biomass before gasification and reduce the moisture content to the suitable and economic level. The well-known solutions are either natural drying (not practical for commercial plants) or conventional drying technologies (have high operating costs). Biodrying is an alternative process, which uses both convective air and heat of biological reactions as a source of energy, to reduce the moisture. In the biodrying reactor heat is generated from exothermic decomposition of organic fraction of biomass and that is why the process is called "self-heating process". Employing such technology for drying biomass at pre-treatment units of gasification process returns several economic and environmental advantages to mills. In Europe, municipal waste treatment (MSW) plants use the biodrying at commercial scale to degrade a part of the biodegradable fraction of waste to generate heat and reduce the moisture content for high quality SRF (Solid Recovered Fuel) production. In Italy, wine industry is seeking to develop biodrying for energy recovery of grape wastes after fermentation and distillation, which returns economic benefits to the industry. In Canada, the development of biodrying technology for pulp and paper industry was started at Ecole polytechnique de Montreal as an option for sludge management solution. Therefore, batch biodrying reactor was successfully developed in 2004

Nitrogen cycling in an integrated biomass for energy system

International Nuclear Information System (INIS)

Moorhead, K.K.

1986-01-01

A series of experiments was conducted to evaluate N cycling in three components of an integrated biomass for energy system, i.e. water hyacinth production, anaerobic digestion in hyacinth biomass, and recycling of digester effluent and sludge. Plants assimilated 50 to 90% of added N in hyacinth production systems. Up to 28% of the total plant N was contained in hyacinth detritus. Nitrogen loading as plant detritus into hyacinth ponds was 92 to 148 kg N ha -1 yr -1 . Net mineralization of plant organic 15 N during anaerobic digestion was 35 and 70% for water hyacinth plants with low and high N content, respectively. Approximately 20% of the 15 N was recovered in the digested sludge while the remaining 15 N was recovered in the effluent. Water hyacinth growth in digester effluents was affected by electrical conductivity and 15 NH 4 + -N concentration. Addition of water hyacinth biomass to soil resulted in decomposition of 39 to 50% of added C for fresh plant biomass and 19 to 23% of added C for digested biomass sludge. Only 8% of added 15 N in digested sludges was mineralized to 15 NO 3 - -N despite differences in initial N content. In contrast, 3 and 33% of added 15 N in fresh biomass with low and high N content, respectively, was recovered as 15 NO 3 - -N. Total 15 N recovery after anaerobic digestion ranged from 70 to 100% of the initial plant biomass 15 N. Total N recovery by sludge and effluent recycling in the integrated biomass for energy system was 48 to 60% of the initial plant biomass 15 N

Hydrothermal Liquefaction of Enzymatic Hydrolysis Lignin: Biomass Pretreatment Severity Affects Lignin Valorization

DEFF Research Database (Denmark)

Jensen, Mads M.; Djajadi, Demi T.; Torri, Cristian

2018-01-01

Alkalinehydrothermal liquefaction (HTL) of lignin-rich enzymatichydrolysis residues (EnzHR) from wheat straw and Miscanthusx giganteus was performed at 255, 300, and 345 °C to investigate valorization of this side-stream from second-generation bioethanol production. The EnzHR were from biomass...... contributed with additional chemical information as well as confirming trends seen from quantified monomers. This work is relevant for future lignin valorization in biorefineries based on current second-generation bioethanol production....

Factors Affecting Microbial Contamination of Market Eggs: A Review

Directory of Open Access Journals (Sweden)

Svobodová J.

2015-01-01

Full Text Available The aim of the review was to analyze the ways of microbial contamination, the protective mechanism of egg, and factors that affect the quantity of contamination and microbial penetration. Eggs can be contaminated during their formation in the infected reproductive organs of hens or after laying, when eggs are exposed to contaminated environment. The eggs are equipped against microbial contamination by several protective mechanisms comprising the presence of cuticle, eggshell, eggshell membranes, occurrence of some antibacterial proteins, and high pH value of albumen. There are several factors that affect the quantity of microbial contamination and penetration such as species of bacteria, the amount of microorganisms, storage conditions, quality of eggshell or number of pores.

Biomass Energy Basics | NREL

Science.gov (United States)

Biomass Energy Basics Biomass Energy Basics We have used biomass energy, or "bioenergy" keep warm. Wood is still the largest biomass energy resource today, but other sources of biomass can landfills (which are methane, the main component in natural gas) can be used as a biomass energy source. A

ORIGINAL ARTICLES Factors affecting career preferences of ...

African Journals Online (AJOL)

College of Medicine prefer to work as doctors, and (ii) what factors may affect their long-term retention in their home country? Methods. We designed ... from rural areas and small towns, and whose parents were 'non- professionals', were .... needs – 5; city life can be difficult – 3; one is closer to family – 2; there is a sense of ...

Karoo-fynbos biomass along an elevational gradient in the western Cape.

Directory of Open Access Journals (Sweden)

M. C. Rutherford

1978-12-01

Full Text Available A short characterization of the vegetational gradient from two basic physiognomic forms of fynbos, through Renosterbosveld to arid Karoo vegetation of the south-western Cape, is given with reference to possible vegetational analogues within similar gradients in winter-rainfall areas elsewhere. Description is limited to some aspects affecting biomass and its measurement, as well as to consideration of community stability needed for valid comparison of community biomass. Live individuals, including single dominant species, all other shrubs, graminoids and other herbaceous species as well as dead individuals were harvested separately in each major community type within an elevational gradient corresponding to the vegetational gradient described. Greatest biomass (14311 kg ha-1 was found in a summit restionaceous community, while lowest biomass (7564 kg ha-1 was found in a low-lying succulent Karoo community. There was an inverse relationship between elevation and percentage dead material mass and a strongly positive relationship between elevation and percentage biomass of the graminoid group. Total biomass values appear to be in keeping with available data for analogue communities in different Mediterranean climate areas, although distinct differences sometimes occur in the relative biomass contributions of component groups.

Evaluation on the Efficiency of Biomass Power Generation Industry in China

Directory of Open Access Journals (Sweden)

Jingqi Sun

2014-01-01

Full Text Available As a developing country with large population, China is facing the problems of energy resource shortage and growing environmental pollution arising from the coal-dominated energy structure. Biomass energy, as a kind of renewable energy with the characteristics of being easy to store and friendly to environment, has become the focus of China’s energy development in the future. Affected by the advanced power generation technology and diversified geography environment, the biomass power generation projects show new features in recent years. Hence, it is necessary to evaluate the efficiency of biomass power generation industry by employing proper method with the consideration of new features. In this paper, the regional difference as a new feature of biomass power generation industry is taken into consideration, and the AR model is employed to modify the zero-weight issue when using data envelopment analysis (DEA method to evaluate the efficiency of biomass power generation industry. 30 biomass power generation enterprises in China are selected as the sample, and the efficiency evaluation is performed. The result can provide some insights into the sustainable development of biomass power generation industry in China.

Factors affecting compliance to treatment among children with ...

African Journals Online (AJOL)

BACKGROUND:This study aimed to determine the factors affecting compliance to treatment among children with epilepsy in Enugu,Nigeria. METHODS: Children with diagnosis of epilepsy were consecutively recruited.Their 6 months retrospective and 1 month prospective data were collected;and analyzed using SPSS ...

Siting Evaluation for Biomass-Ethanol Production in Hawaii

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, C.M.; Zhou, J.

2000-10-15

This report examines four Hawaiian islands, Oahu, Hawaii, Maui, and Kauai, to identify three best combinations of potential sites and crops for producing dedicated supplies of biomass for conversion to ethanol. Key technical and economic factors considered in the siting evaluation include land availability (zoning and use), land suitability (agronomic conditions), potential quantities and costs of producing biomass feedstocks, infrastructure (including water and power supplies), transportation, and potential bioresidues to supplement dedicated energy crops.

Emission factors and chemical characterisation of fine particulate emissions from modern and old residential biomass heating systems determined for typical load cycles; Emissionsfaktoren und chemische Charakterisierung von Feinstaubemissionen moderner und alter Biomasse-Kleinfeuerungen ueber typische Tageslastverlaeufe

Energy Technology Data Exchange (ETDEWEB)

Kelz, Joachim [BIOENERGY 2020+ GmbH, Graz (Austria); Brunner, Thomas; Obernberger, Ingwald [BIOENERGY 2020+ GmbH, Graz (Austria); Technische Universitaet Graz, Institut fuer Prozess- und Partikeltechnik, Graz (Austria); BIOS BIOENERGIESYSTEME GmbH, Graz (Austria)

2012-12-15

It is already well known that there are significant differences regarding the emissions, especially particulate matter (PM) emissions, of old and modern as well as automatically and not automatically controlled biomass based residential heating systems. This concerns their magnitude as well as their chemical composition. In order to investigate emission factors for particulate emissions and the chemical compositions of the PM emissions over typical whole day operation cycles, a project on the determination and characterisation of PM emissions from the most relevant small-scale biomass combustion systems was performed at the BIOENERGY 2020+ GmbH, Graz, Austria, in cooperation with the Institute for Process and Particle Engineering, Graz University of Technology. The project was based on test stand measurements, during which relevant operation parameters (gaseous emissions, boiler load, flue gas temperature, combustion chamber temperature etc.) as well as PM emissions have been measured and PM samples have been taken and forwarded to chemical analyses. Firstly, typical whole day operation cycles for residential biomass combustion systems were specified for the test runs. Thereby automatically fed and automatically controlled boilers, manually fed and automatically controlled boilers as well as manually fed stoves were distinguished. The results show a clear correlation between the gaseous emissions (CO and OGC) and the PM{sub 1} emissions. It is indicated that modern biomass combustion systems emit significantly less gaseous and PM emissions than older technologies (up to a factor of 100). Moreover, automatically fed systems emit much less gaseous and PM emissions than manually fed batch-combustion systems. PM emissions from modern and automatically controlled systems mainly consist of alkaline metal salts, while organic aerosols and soot dominate the composition of aerosols from old and not automatically controlled systems. As an important result comprehensive data

Factors affecting the tissues composition of pork belly.

Science.gov (United States)

Duziński, K; Knecht, D; Lisiak, D; Janiszewski, P

2015-11-01

Bellies derived from the commercial population of pig carcasses are diverse in terms of tissue composition. Knowledge of the factors influencing it and the expected results, permits quick and easy evaluation of raw material. The study was designed to determine the factors affecting the tissues composition of pork bellies and to estimate their lean meat content. The research population (n=140 pig carcasses) was divided into groups according to sex (gilts, barrows), half-carcass mass (meat content class: S (⩾60%), E (55% to 60%), U (50% to 55%), R (meat content affected the growth of the fat and skin mass in a linear way. No differences were observed between class S and E in terms of belly muscle mass. A 0.37% higher share of belly in the half-carcass was found for barrows (Pmeat content in bellies, suggesting they may be used directly in the production line.

Cognitive Factors Affecting Freeze-like Behavior in Humans.

Science.gov (United States)

Alban, Michael W; Pocknell, Victoria

2017-01-01

Contemporary research on survival-related defensive behaviors has identified physiological markers of freeze/flight/fight. Our research focused on cognitive factors associated with freeze-like behavior in humans. Study 1 tested if an explicit decision to freeze is associated with the psychophysiological state of freezing. Heart rate deceleration occurred when participants chose to freeze. Study 2 varied the efficacy of freezing relative to other defense options and found "freeze" was responsive to variations in the perceived effectiveness of alternative actions. Study 3 tested if individual differences in motivational orientation affect preference for a "freeze" option when the efficacy of options is held constant. A trend in the predicted direction suggested that naturally occurring cognitions led loss-avoiders to select "freeze" more often than reward-seekers. In combination, our attention to the cognitive factors affecting freeze-like behavior in humans represents a preliminary step in addressing an important but neglected research area.

Decoupling factors affecting plant diversity and cover on extensive green roofs.

Science.gov (United States)

MacIvor, J Scott; Margolis, Liat; Puncher, Curtis L; Carver Matthews, Benjamin J

2013-11-30

Supplemental irrigation systems are often specified on green roofs to ensure plant cover and growth, both important components of green roof performance and aesthetics. Properties of the growing media environment too can alter the assemblage of plant species able to thrive. In this study we determine how plant cover, above ground biomass and species diversity are influenced by irrigation and growing media. Grass and forb vegetative cover and biomass were significantly greater in organic based growing media but there was no effect of supplemental irrigation, with two warm season grasses dominating in those treatments receiving no supplemental irrigation. On the other hand, plant diversity declined without irrigation in organic media, and having no irrigation in inorganic growing media resulted in almost a complete loss of cover. Sedum biomass was less in inorganic growing media treatments and species dominance shifted when growing media organic content increased. Our results demonstrate that supplemental irrigation is required to maintain plant diversity on an extensive green roof, but not necessarily plant cover or biomass. These results provide evidence that planting extensive green roofs with a mix of plant species can ensure the survival of some species; maintaining cover and biomass when supplemental irrigation is turned off to conserve water, or during extreme drought. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Factors affecting cardiac rehabilitation referral by physician specialty.

Science.gov (United States)

Grace, Sherry L; Grewal, Keerat; Stewart, Donna E

2008-01-01

Cardiac rehabilitation (CR) is widely underutilized because of multiple factors including physician referral practices. Previous research has shown CR referral varies by type of provider, with cardiologists more likely to refer than primary care physicians. The objective of this study was to compare factors affecting CR referral in primary care physicians versus cardiac specialists. A cross-sectional survey of a stratified random sample of 510 primary care physicians and cardiac specialists (cardiologists or cardiovascular surgeons) in Ontario identified through the Canadian Medical Directory Online was administered. One hundred four primary care physicians and 81 cardiac specialists responded to the 26-item investigator-generated survey examining medical, demographic, attitudinal, and health system factors affecting CR referral. Primary care physicians were more likely to endorse lack of familiarity with CR site locations (P negatively impacting CR referral practices than cardiac specialists. Cardiac specialists were significantly more likely to perceive that their colleagues and department would regularly refer patients to CR than primary care physicians (P Marketing CR site locations, provision of standardized referral forms, and ensuring discharge summaries are communicated to primary care physicians may improve their willingness to refer to CR.

Anthropogenic Land-use Change and the Dynamics of Amazon Forest Biomass

Science.gov (United States)

Laurance, William F.

2004-01-01

This project was focused on assessing the effects of prevailing land uses, such as habitat fragmentation, selective logging, and fire, on biomass and carbon storage in Amazonian forests, and on the dynamics of carbon sequestration in regenerating forests. Ancillary goals included developing GIs models to help predict the future condition of Amazonian forests, and assessing the effects of anthropogenic climate change and ENS0 droughts on intact and fragmented forests. Ground-based studies using networks of permanent plots were linked with remote-sensing data (including Landsat TM and AVHRR) at regional scales, and higher-resolution techniques (IKONOS imagery, videography, LIDAR, aerial photographs) at landscape and local scales. The project s specific goals were quite eclectic and included: Determining the effects of habitat fragmentation on forest dynamics, floristic composition, and the various components of above- and below-ground biomass. Assessing historical and physical factors that affect trajectories of forest regeneration and carbon sequestration on abandoned lands. Extrapolating results from local studies of biomass dynamics in fragmented and regenerating forests to landscape and regional scales in Amazonia, using remote sensing and GIS. Testing the hypothesis that intact Amazonian forests are functioning as a significant carbon sink. Examining destructive synergisms between forest fragmentation and fire. Assessing the short-term impacts of selective logging on aboveground biomass. Developing GIS models that integrate current spatial data on forest cover, deforestation, logging, mining, highway and roads, navigable rivers, vulnerability to wild fires, protected areas, and existing and planned infrastructure projects, in an effort to predict the future condition of Brazilian Amazonian forests over the next 20-25 years. Devising predictive spatial models to assess the influence of varied biophysical and anthropogenic predictors on Amazonian deforestation.

Changes in forest biomass and linkage to climate and forest disturbances over Northeastern China.

Science.gov (United States)

Zhang, Yuzhen; Liang, Shunlin

2014-08-01

The forests of northeastern China store nearly half of the country's total biomass carbon stocks. In this study, we investigated the changes in forest biomass by using satellite observations and found that a significant increase in forest biomass took place between 2001 and 2010. To determine the possible reasons for this change, several statistical methods were used to analyze the correlations between forest biomass dynamics and forest disturbances (i.e. fires, insect damage, logging, and afforestation and reforestation), climatic factors, and forest development. Results showed that forest development was the most important contributor to the increasing trend of forest biomass from 2001 to 2010, and climate controls were the secondary important factor. Among the four types of forest disturbance considered in this study, forest recovery from fires, and afforestation and reforestation during the past few decades played an important role in short-term biomass dynamics. This study provided observational evidence and valuable information for the relationships between forest biomass and climate as well as forest disturbances. © 2014 John Wiley & Sons Ltd.

A dataset of forest biomass structure for Eurasia.

Science.gov (United States)

Schepaschenko, Dmitry; Shvidenko, Anatoly; Usoltsev, Vladimir; Lakyda, Petro; Luo, Yunjian; Vasylyshyn, Roman; Lakyda, Ivan; Myklush, Yuriy; See, Linda; McCallum, Ian; Fritz, Steffen; Kraxner, Florian; Obersteiner, Michael

2017-05-16

The most comprehensive dataset of in situ destructive sampling measurements of forest biomass in Eurasia have been compiled from a combination of experiments undertaken by the authors and from scientific publications. Biomass is reported as four components: live trees (stem, bark, branches, foliage, roots); understory (above- and below ground); green forest floor (above- and below ground); and coarse woody debris (snags, logs, dead branches of living trees and dead roots), consisting of 10,351 unique records of sample plots and 9,613 sample trees from ca 1,200 experiments for the period 1930-2014 where there is overlap between these two datasets. The dataset also contains other forest stand parameters such as tree species composition, average age, tree height, growing stock volume, etc., when available. Such a dataset can be used for the development of models of biomass structure, biomass extension factors, change detection in biomass structure, investigations into biodiversity and species distribution and the biodiversity-productivity relationship, as well as the assessment of the carbon pool and its dynamics, among many others.

Biomass and Swedish energy policy

International Nuclear Information System (INIS)

Johansson, Bengt

2001-01-01

The use of biomass in Sweden has increased by 44% between 1990 and 1999. In 1999 it was 85 TWh, equivalent to 14% of the total Swedish energy supply. The existence of large forest industry and district heating systems has been an essential condition for this expansion. The tax reform in 1991 seems, however, to have been the most important factor responsible for the rapid bioenergy expansion. Through this reform, the taxation of fossil fuels in district heating systems increased by approximately 30-160%, depending on fuel, whereas bioenergy remained untaxed. Industry is exempted from the energy tax and pays reduced carbon tax. No tax is levied on fossil fuels used for electricity production. Investment grants have existed for biomass-based electricity production but these grants have not been large enough to make biomass-based electricity production economically competitive in a period of falling electricity prices. Despite this, the biomass-based electricity production has increased slightly between 1990 and 1999. A new taxation system aiming at a removal of the tax difference between the industry, district heating and electricity sectors has recently been analysed by the Swedish government. One risk with such a system is that it reduces the competitiveness for biomass in district heating systems as it seems unlikely that the taxes on fossil fuels in the industry and electricity sectors will increase to a level much higher than in other countries. A new system, based on green certificates, for supporting electricity from renewable energy sources has also been proposed by the government.

Solid biomass barometer - EurObserv'ER - December 2016

International Nuclear Information System (INIS)

2016-12-01

Solid biomass consumption, primarily wood energy, is still largely governed by heating requirements which are climate-dependent. The main factor for the European rebound in solid biomass consumption as primary energy during the winter of 2015 is that it was not as mild across the continent as the previous winter. Leaving aside climatic variations, the use of solid biomass for producing heat or electricity has tended to increase in the European Union, spurred on by European support policies. A new consumption record of 93.8 Mtoe was posted in 2015... a rise of 3.8 Mtoe over 2014

Biomass Supply Chain and Conversion Economics of Cellulosic Ethanol

Science.gov (United States)

Gonzalez, Ronalds W.

2011-12-01

Cellulosic biomass is a potential and competitive source for bioenergy production, reasons for such acclamation include: biomass is one the few energy sources that can actually be utilized to produce several types of energy (motor fuel, electricity, heat) and cellulosic biomass is renewable and relatively found everywhere. Despite these positive advantages, issues regarding cellulosic biomass availability, supply chain, conversion process and economics need a more comprehensive understanding in order to identify the near short term routes in biomass to bioenergy production. Cellulosic biomass accounts for around 35% to 45% of cost share in cellulosic ethanol production, in addition, different feedstock have very different production rate, (dry ton/acre/year), availability across the year, and chemical composition that affect process yield and conversion costs as well. In the other hand, existing and brand new conversion technologies for cellulosic ethanol production offer different advantages, risks and financial returns. Ethanol yield, financial returns, delivered cost and supply chain logistic for combinations of feedstock and conversion technology are investigated in six studies. In the first study, biomass productivity, supply chain and delivered cost of fast growing Eucalyptus is simulated in economic and supply chain models to supply a hypothetic ethanol biorefinery. Finding suggests that Eucalyptus can be a potential hardwood grown specifically for energy. Delivered cost is highly sensitive to biomass productivity, percentage of covered area. Evaluated at different financial expectations, delivered cost can be competitive compared to current forest feedstock supply. In the second study, Eucalyptus biomass conversion into cellulosic ethanol is simulated in the dilute acid pretreatment, analysis of conversion costs, cost share, CAPEX and ethanol yield are examined. In the third study, biomass supply and delivered cost of loblolly pine is simulated in economic

Key factors for achieving profitable biogas production from agricultural waste and sustainable biomass

DEFF Research Database (Denmark)

Molinuevo-Salces, Beatriz; Larsen, Søren U.; Biswas, Rajib

2013-01-01

Based on numerous investigations on increasing the biogas yield of manure, a new concept was developed to increase the economical operation of manure based biogas plants by combining up concentration of manure with a more specific treatment of the recalcitrant lignocellulosic fiber fraction...... by implementing the treatment on the digested solid fraction. Catch crops have been identified as a sustainable co-substrate for biogas production with a high biogas potential. For exploiting this biomass for profitable biogas production, the biomass yield per hectare, harvest costs, TS concentration and specific...

Biomass models to estimate carbon stocks for hardwood tree species

Energy Technology Data Exchange (ETDEWEB)

Ruiz-Peinado, R.; Montero, G.; Rio, M. del

2012-11-01

To estimate forest carbon pools from forest inventories it is necessary to have biomass models or biomass expansion factors. In this study, tree biomass models were developed for the main hardwood forest species in Spain: Alnus glutinosa, Castanea sativa, Ceratonia siliqua, Eucalyptus globulus, Fagus sylvatica, Fraxinus angustifolia, Olea europaea var. sylvestris, Populus x euramericana, Quercus canariensis, Quercus faginea, Quercus ilex, Quercus pyrenaica and Quercus suber. Different tree biomass components were considered: stem with bark, branches of different sizes, above and belowground biomass. For each species, a system of equations was fitted using seemingly unrelated regression, fulfilling the additivity property between biomass components. Diameter and total height were explored as independent variables. All models included tree diameter whereas for the majority of species, total height was only considered in the stem biomass models and in some of the branch models. The comparison of the new biomass models with previous models fitted separately for each tree component indicated an improvement in the accuracy of the models. A mean reduction of 20% in the root mean square error and a mean increase in the model efficiency of 7% in comparison with recently published models. So, the fitted models allow estimating more accurately the biomass stock in hardwood species from the Spanish National Forest Inventory data. (Author) 45 refs.

Structure of Caribbean coral reef communities across a large gradient of fish biomass.

Science.gov (United States)

Newman, Marah J H; Paredes, Gustavo A; Sala, Enric; Jackson, Jeremy B C

2006-11-01

The collapse of Caribbean coral reefs has been attributed in part to historic overfishing, but whether fish assemblages can recover and how such recovery might affect the benthic reef community has not been tested across appropriate scales. We surveyed the biomass of reef communities across a range in fish abundance from 14 to 593 g m(-2), a gradient exceeding that of any previously reported for coral reefs. Increased fish biomass was correlated with an increased proportion of apex predators, which were abundant only inside large marine reserves. Increased herbivorous fish biomass was correlated with a decrease in fleshy algal biomass but corals have not yet recovered.

Biomass production efficiency controlled by management in temperate and boreal ecosystems

Science.gov (United States)

Campioli, M.; Vicca, S.; Luyssaert, S.; Bilcke, J.; Ceschia, E.; Chapin, F. S., III; Ciais, P.; Fernández-Martínez, M.; Malhi, Y.; Obersteiner, M.; Olefeldt, D.; Papale, D.; Piao, S. L.; Peñuelas, J.; Sullivan, P. F.; Wang, X.; Zenone, T.; Janssens, I. A.

2015-11-01

Plants acquire carbon through photosynthesis to sustain biomass production, autotrophic respiration and production of non-structural compounds for multiple purposes. The fraction of photosynthetic production used for biomass production, the biomass production efficiency, is a key determinant of the conversion of solar energy to biomass. In forest ecosystems, biomass production efficiency was suggested to be related to site fertility. Here we present a database of biomass production efficiency from 131 sites compiled from individual studies using harvest, biometric, eddy covariance, or process-based model estimates of production. The database is global, but dominated by data from Europe and North America. We show that instead of site fertility, ecosystem management is the key factor that controls biomass production efficiency in terrestrial ecosystems. In addition, in natural forests, grasslands, tundra, boreal peatlands and marshes, biomass production efficiency is independent of vegetation, environmental and climatic drivers. This similarity of biomass production efficiency across natural ecosystem types suggests that the ratio of biomass production to gross primary productivity is constant across natural ecosystems. We suggest that plant adaptation results in similar growth efficiency in high- and low-fertility natural systems, but that nutrient influxes under managed conditions favour a shift to carbon investment from the belowground flux of non-structural compounds to aboveground biomass.

Systems Level Regulation of Rhythmic Growth Rate and Biomass Accumulation in Grasses

Energy Technology Data Exchange (ETDEWEB)

Kay, Steve A. [Scripps Research Inst., La Jolla, CA (United States); Hazen, Samuel [Scripps Research Inst., San Diego, CA (United States); Mullet, John [Texas A & M Univ., College Station, TX (United States)

2017-11-22

Critical to the development of renewable energy sources from biofuels is the improvement of biomass from energy feedstocks, such as sorghum and maize. The specific goals of this project include 1) characterize the growth and gene expression patterns under diurnal and circadian conditions, 2) select transcription factors associated with growth and build a cis-regulatory network in yeast, and 3) perturb these transcription factors in planta using transgenic Brachypodium and sorghum, and characterize the phenotypic outcomes as they relate to biomass accumulation. A better understanding of diurnally regulated growth behavior in grasses may lead to species-specific mechanisms highly relevant to future strategies to optimize energy crop biomass yield.

Biomass CCS study

Energy Technology Data Exchange (ETDEWEB)

Cavezzali, S.

2009-11-15

The use of biomass in power generation is one of the important ways in reducing greenhouse gas emissions. Specifically, the cofiring of biomass with coal could be regarded as a common feature to any new build power plant if a sustainable supply of biomass fuel is readily accessible. IEA GHG has undertaken a techno-economic evaluation of the use of biomass in biomass fired and co-fired power generation, using post-combustion capture technology. This report is the result of the study undertaken by Foster Wheeler Italiana.

Soil microbial biomass in an agroforestry system of Northeast Brazil

Directory of Open Access Journals (Sweden)

Rosane C. Rodrigues

2015-01-01

Full Text Available Agroforestry systems (AFS are considered alternative land use options to help prevent soil degradation and improve soil microbial biomass and organic C status. However, it is unclear how different densities of babassu palm [Attalea speciosa (syn. Orbignya phalerata], which is an important tree in Northeast Brazil, affect the soil microbial biomass. We investigated the soil microbial biomass C and activity under AFS with different densities of babassu palm associated with Brachiaria brizantha grass. Soil microbial biomass C (MBC, soil microbial biomass N (MBN, MBC:total organic C ratio, fluorescein diacetate hydrolysis and dehydrogenase activity showed highest values in plots with high density of babassu palm. On the other hand, the respiratory quotient (qCO2 was significantly greater in plots without babassu palm. Brachiaria brizantha in monoculture may promote C losses from the soil, but AFS with high density of babassu palm may increase the potential of soils to accumulate C.Keywords: Enzyme activity, tropical soil, babassu palm, silvopastoral system, soil quality.DOI: 10.17138/TGFT(341-48

Policy factors affecting broadband development in Poland

DEFF Research Database (Denmark)

Henten, Anders; Windekilde, Iwona Maria

2014-01-01

of telecommunications network development in Poland than other countries in the European Union is the reason that the circumstances and also the effects of the implementation of some solutions of the EU regulation model are different in Poland than in the most developed EU countries. The aim of the paper is to examine...... and discuss broadband access development in Poland and the policy factors influencing this development as well as to examine national strategies used to stimulate service and infrastructure competition in Poland. There are, indeed, many other factors affecting broadband development such as the income level....../distribution in the country and the infrastructural point of departure. The paper, therefore, analyses the implications of the policy initiatives in light of these basic conditions and the broader context of factors influencing broadband development. In the paper, different kinds of policy initiatives are examined...

Projecting demand and supply of forest biomass for heating in Norway

International Nuclear Information System (INIS)

Tromborg, Erik; Havskjold, Monica; Lislebo, Ole; Rorstad, Per Kristian

2011-01-01

This paper assesses the increase in demand and supply for forest biomass for heating in Norway in 2020. By then there is a political aim to double the national production of bioenergy from the level in 2008. The competitiveness of woody biomass in central and district heating is analyzed in a model selecting the least-cost heating technology and scale in municipalities given a set of constraints and under different fuels price scenarios. The supply of forest biomass from roundwood is estimated based on data of forest inventories combined with elasticities regarding price and standing volumes. The supply of biomass from harvesting residues is estimated in an engineering approach based on data from the national forest inventories and roundwood harvest. The results show how the production of bioenergy is affected by changes in energy prices and support schemes for bioenergy. One conclusion from the analyses is that the government target of 14 TWh more bioenergy by 2020 is not likely to be met by current technologies and policy incentives. The contribution of the analysis is the detailed presentation of the heat market potentials and technology choices combined with supply functions for both roundwood and harvesting residues. - Highlights: → This paper accesses the demand and supply for forest biomass for heating in Norway in 2020. → Market share for wood in central and new district heating is analyzed in a cost-minimizing model. → The supply of forest biomass includes wood chips from import, roundwood and harvesting residues. → The production of bioenergy is affected by changes in energy prices and support schemes. → The government target for bioenergy is not met by current technologies and policy incentives.

An Improved Reinforcement Learning System Using Affective Factors

Directory of Open Access Journals (Sweden)

Takashi Kuremoto

2013-07-01

Full Text Available As a powerful and intelligent machine learning method, reinforcement learning (RL has been widely used in many fields such as game theory, adaptive control, multi-agent system, nonlinear forecasting, and so on. The main contribution of this technique is its exploration and exploitation approaches to find the optimal solution or semi-optimal solution of goal-directed problems. However, when RL is applied to multi-agent systems (MASs, problems such as “curse of dimension”, “perceptual aliasing problem”, and uncertainty of the environment constitute high hurdles to RL. Meanwhile, although RL is inspired by behavioral psychology and reward/punishment from the environment is used, higher mental factors such as affects, emotions, and motivations are rarely adopted in the learning procedure of RL. In this paper, to challenge agents learning in MASs, we propose a computational motivation function, which adopts two principle affective factors “Arousal” and “Pleasure” of Russell’s circumplex model of affects, to improve the learning performance of a conventional RL algorithm named Q-learning (QL. Compared with the conventional QL, computer simulations of pursuit problems with static and dynamic preys were carried out, and the results showed that the proposed method results in agents having a faster and more stable learning performance.

Nurse aide decision making in nursing homes: factors affecting empowerment.

Science.gov (United States)

Chaudhuri, Tanni; Yeatts, Dale E; Cready, Cynthia M

2013-09-01

To evaluate factors affecting structural empowerment among nurse aides in nursing homes. Structural empowerment can be defined as the actual rather than perceived ability to make autonomous decisions within an organisation. Given the paucity of research on the subject, this study helps to close the gap by identifying factors that affect nurse aide empowerment, that is, decision-making among nurse aides. The data for the study come from self-administered questionnaires distributed to direct-care workers (nurse aides) in 11 nursing homes in a southern state in the USA. Ordinary least square regression models were estimated to analyse the effects of demographic predictors, personal factors (competency, emotional exhaustion and positive attitude) and structural characteristics (coworker and supervisor support, information availability and shared governance) on nurse aide decision-making. Findings suggest race among demographic predictors, emotional exhaustion among personal characteristics, and supervisor support, and shared governance among structural factors, significantly affect nurse aide decision-making. It is important to explore race as one of the central determinants of structural empowerment among nurse aides. In addition, the nature and type of emotional exhaustion that propels decision-making needs to be further examined. The study shows the importance of shared governance and supervisor support for fostering nurse aide empowerment. © 2013 Blackwell Publishing Ltd.

Silvicultural manipulation and site effect on above and belowground biomass equations for young Pinus radiata

International Nuclear Information System (INIS)

Rubilar, Rafael A.; Allen, H. Lee; Alvarez, Jose S.; Albaugh, Timothy J.; Fox, Thomas R.; Stape, Jose L.

2010-01-01

There is little understanding of how silvicultural treatments, during the early stages of tree development, affect allometric relationships. We developed and compared stem, branch, foliage, coarse and fine root biomass, and leaf area estimation equations, for four-year-old genetically improved radiata pine trees grown on three contrasting soil-site conditions. At each site, selected trees were destructively sampled from a control (shovel planted, no weed control, fertilized with 2 g of boron), a shovel planted + weed control (2 first years) + complete fertilization (nitrogen + phosphorus + boron 2 first years + potassium 2nd year), and a soil tillage (subsoil at 60 cm) + weed control (first 2 years) + complete fertilization treatment. Tissues were separated into foliage, branch, stem, fine and coarse roots (>2 mm). Regression equations for each tree biomass tissue versus leaf area were fit for each site and compared among treatments and sites with the same genetic material. Our results indicated that individual tree biomasses for young plantations are affected by silvicultural treatment and site growing conditions. Higher variability in estimates was found for foliage and branches due to the ephemeral nature of these components. Stem biomass equations vary less, but differences in biomass equations were found among sites and treatments. Coarse root biomass estimates were variable but less than expected, considering the gradient among sites. Similar to stem biomass, a simple positive general linear relationship between root collar diameter, or diameter at breast height with coarse roots biomass was developed across sites and treatments.

Biomass pretreatment

Science.gov (United States)

Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

2013-05-21

A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

Field determination of biomass burning emission ratios and factors via open-path FTIR spectroscopy and fire radiative power assessment: headfire, backfire and residual smouldering combustion in African savannahs

CSIR Research Space (South Africa)

Wooster, MJ

2011-01-01

Full Text Available Biomass burning emissions factors are vital to quantifying trace gases releases from vegetation fires. Here the authors evaluate emissions factors for a series of savannah fires in Kruger National Park (KNP), South Africa using ground-based open...

Structural stability, microbial biomass and community composition of sediments affected by the hydric dynamics of an urban stormwater infiltration basin. Dynamics of physical and microbial characteristics of stormwater sediment.

Science.gov (United States)

Badin, Anne Laure; Monier, Armelle; Volatier, Laurence; Geremia, Roberto A; Delolme, Cécile; Bedell, Jean-Philippe

2011-05-01

The sedimentary layer deposited at the surface of stormwater infiltration basins is highly organic and multicontaminated. It undergoes considerable moisture content fluctuations due to the drying and inundation cycles (called hydric dynamics) of these basins. Little is known about the microflora of the sediments and its dynamics; hence, the purpose of this study is to describe the physicochemical and biological characteristics of the sediments at different hydric statuses of the infiltration basin. Sediments were sampled at five time points following rain events and dry periods. They were characterized by physical (aggregation), chemical (nutrients and heavy metals), and biological (total, bacterial and fungal biomasses, and genotypic fingerprints of total bacterial and fungal communities) parameters. Data were processed using statistical analyses which indicated that heavy metal (1,841 μg/g dry weight (DW)) and organic matter (11%) remained stable through time. By contrast, aggregation, nutrient content (NH₄⁺, 53-717 μg/g DW), pH (6.9-7.4), and biological parameters were shown to vary with sediment water content and sediment biomass, and were higher consecutive to stormwater flows into the basin (up to 7 mg C/g DW) than during dry periods (0.6 mg C/g DW). Coinertia analysis revealed that the structure of the bacterial communities is driven by the hydric dynamics of the infiltration basin, although no such trend was found for fungal communities. Hydric dynamics more than rain events appear to be more relevant for explaining variations of aggregation, microbial biomass, and shift in the microbial community composition. We concluded that the hydric dynamics of stormwater infiltration basins greatly affects the structural stability of the sedimentary layer, the biomass of the microbial community living in it and its dynamics. The decrease in aggregation consecutive to rewetting probably enhances access to organic matter (OM), explaining the consecutive release

High Pressure Biomass Gasification

Energy Technology Data Exchange (ETDEWEB)

Agrawal, Pradeep K [Georgia Tech Research Corporation, Atlanta, GA (United States)

2016-07-29

According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO₂ emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDO hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H₂). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However

Factors Affecting Utilization of Cooking Banana among Households ...

African Journals Online (AJOL)

The study investigated factors affecting utilization of cooking banana among households in Oguta area of Imo State, Nigeria. Data were collected from 84 randomly selected respondents from six communities in the study area who were administered with structured questionnaire. Data analysis was by use of descriptive ...

Factors Affecting Academic Achievement of Students in Senior ...

African Journals Online (AJOL)

The study investigated the factors affecting academic achievement ofstudents in Senior School Certificate Examination (SSCE) in ChristianReligious Knowledge. A total of three hundred students in SS III from five secondary schools were randomly selected and used as sample for the study. Five hypotheses were tested, ...

Nutritional Factors Affecting Adult Neurogenesis and Cognitive Function

Science.gov (United States)

Adult neurogenesis, a complex process by which stem cells in the hippocampal brain region differentiate and proliferate into new neurons and other resident brain cells, is known to be affected by many intrinsic and extrinsic factors, including diet. Neurogenesis plays a critical role in neural plas...

Dynamics of global vegetation biomass simulated by the integrated Earth System Model

Science.gov (United States)

Mao, J.; Shi, X.; Di Vittorio, A. V.; Thornton, P. E.; Piao, S.; Yang, X.; Truesdale, J. E.; Bond-Lamberty, B. P.; Chini, L. P.; Thomson, A. M.; Hurtt, G. C.; Collins, W.; Edmonds, J.

2014-12-01

The global vegetation biomass stores huge amounts of carbon and is thus important to the global carbon budget (Pan et al., 2010). For the past few decades, different observation-based estimates and modeling of biomass in the above- and below-ground vegetation compartments have been comprehensively conducted (Saatchi et al., 2011; Baccini et al., 2012). However, uncertainties still exist, in particular for the simulation of biomass magnitude, tendency, and the response of biomass to climatic conditions and natural and human disturbances. The recently successful coupling of the integrated Earth System Model (iESM) (Di Vittorio et al., 2014; Bond-Lamberty et al., 2014), which links the Global Change Assessment Model (GCAM), Global Land-use Model (GLM), and Community Earth System Model (CESM), offers a great opportunity to understand the biomass-related dynamics in a fully-coupled natural and human modeling system. In this study, we focus on the systematic analysis and evaluation of the iESM simulated historical (1850-2005) and future (2006-2100) biomass changes and the response of the biomass dynamics to various impact factors, in particular the human-induced Land Use/Land Cover Change (LULCC). By analyzing the iESM simulations with and without the interactive LULCC feedbacks, we further study how and where the climate feedbacks affect socioeconomic decisions and LULCC, such as to alter vegetation carbon storage. References Pan Y et. al: A large and persistent carbon sink in the World's forests. Science 2011, 333:988-993. Saatchi SS et al: Benchmark map of forest carbon stocks in tropical regions across three continents. Proc Natl Acad Sci 2011, 108:9899-9904. Baccini A et al: Estimated carbon dioxide emissions from tropical deforestation improved by carbon-density maps. Nature Clim Change 2012, 2:182-185. Di Vittorio AV et al: From land use to land cover: restoring the afforestation signal in a coupled integrated assessment-earth system model and the implications for

Internal, external and location factors influencing cofiring of biomass with coal in the U.S. northern region

Science.gov (United States)

Francisco X. Aguilar; Michael E. Goerndt; Nianfu Song; Stephen R. Shifley

2012-01-01

The use of biomass as a source of energy has been identified as a viable option to diminish reliance on fossil fuels. We parameterized the effect of selected internal (e.g. coal-fire presence), external (e.g. price and renewable energy mandates) and location (e.g. biomass availability, infrastructure) variables on the likelihood of using biomass in cofiring with coal...

Biosorption of heavy metals and radionuclide from aqueous solutions by pre-treated arca shell biomass

International Nuclear Information System (INIS)

Dahiya, Sudhir; Tripathi, R.M.; Hegde, A.G.

2008-01-01

In this study biosorption potential of pre-treated arca shell biomass for lead, copper, nickel, cobalt and cesium was explored from the artificially prepared solution containing known amount of metals. The effects of pH, initial concentration, biosorbent dosage and contact time were studied in batch experiments. Effects of common ions like sodium, potassium, calcium and magnesium on the sorption capacity of pre-treated arca biomasses were also studied. To analyse the homogeneity of the biomaterial, experiments were performed for eight lots arca shell biomass for all the studies elements and it was observed that relative standard deviation in uptake capacity was within 10% for all elements. At equilibrium, the maximum total uptake by shell biomaterial was 18.33 ± 0.44, 17.64 ± 0.31, 9.86 ± 0.17, 3.93 ± 0.11 and 7.82 ± 0.36 mg/g for lead, copper, nickel, cesium and cobalt, respectively, under the optimised condition of pH, initial concentration, biosorbent dose and contact time. Effect of all the common ions jointly up to concentration of 50 ppm was negligible for all the elements but at higher levels the cations affects the uptake capacity. Sorption isotherms were studied to explain the removal mechanism of both elements by fitting isotherms data into Lagergren, Freundlich and Langmuir equations. Halls separation factor estimated under optimised condition also favours the sorption potential of these elements using arca shell biomass. Arca shell biomass can be effectively and efficiently employed for removal of studied elements after optimisation of parameters

An Initial Investigation of Factors Affecting Multi-Task Performance

National Research Council Canada - National Science Library

Branscome, Tersa A; Swoboda, Jennifer C; Fatkin, Linda T

2007-01-01

This report presents the results of the first in a series of investigations designed to increase fundamental knowledge and understanding of the factors affecting multi-task performance in a military environment...

Availability of biomass for energy production. GRAIN: Global Restrictions on biomass Availability for Import to the Netherlands

International Nuclear Information System (INIS)

Lysen, E.H.

2000-08-01

The report includes reports of activities that were carried out within the GRAIN project. This evaluation shows that the (technical) potential contribution of bio-energy to the future world's energy supply could be very large. In theory, energy farming on current agricultural land could contribute over 800 EJ, without jeopardising the world's food supply. Use of degraded lands may add another 150 EJ, although this contribution will largely come from crops with a low productivity. The growing demand for bio-materials may require a biomass input equivalent to 20-50 EJ, which must be grown on plantations when existing forests are not able to supply this growing demand. Organic wastes and residues could possibly supply another 40-170 EJ, with uncertain contributions from forest residues and potentially a very significant role for organic waste, especially when bio-materials are used on a larger scale. In total, the upper limit of the bio-energy potential could be over 1000 EJ per year. This is considerably more than the current global energy use of 400 EJ. However, this contribution is by no means guaranteed: crucial factors determining biomass availability for energy are: (1) Population growth and economic development; (2) The efficiency and productivity of food production systems that must be adopted worldwide and the rate of their deployment in particular in developing countries; (3) Feasibility of the use of marginal/degraded lands; (4) Productivity of forests and sustainable harvest levels; (5) The (increased) utilisation of bio-materials. Major transitions are required to exploit this bio-energy potential. It is uncertain to what extent such transitions are feasible. Depending on the factors mentioned above, the bio-energy potential could be very low as well. At regional/local level the possibilities and potential consequences of biomass production and use can vary strongly, but the insights in possible consequences are fairly limited up to now. Bio-energy offers

Factors That Affect Suicidal Attempt Risk Among Korean Elderly Adults: A Path Analysis

Directory of Open Access Journals (Sweden)

Junsoo Ro

2015-01-01

Full Text Available Objectives: Among the Korean elderly (those 65 years of age and older, the suicide rate is 80.3/100 000 people, which is ten times higher than the Organization for Economic Cooperation and Development average. Because South Korea is rapidly becoming an aging population, this high elderly suicidal rate will only get worse. Although the size of the elderly suicide problem is quite large, previous research in South Korea has surveyed restricted areas and not the entire country. Even though the factors that affect elderly suicide are complicated, there has been little research into these influencing factors. Thus, this research uses the national survey data (Community Health Survey that was obtained in 2009. Additionally, we analyze factors affecting elderly suicidal ideation and attempts as well as the paths of these effects. Methods: Community Health Survey data obtained by the Korea Centers for Disease Control and Prevention in 2009 was used for this study. We additionally examined the factors that affect suicide with chi-squared tests, t-tests, Pearson’s correlation test, and path analysis. Results: Depressive symptoms and suicidal ideation are the only factors that directly affect suicidal attempts. Demographic, behavioral, and physical activity factors have indirect effects on suicidal attempts. Conclusions: Depression has the strongest influence on suicidal ideation and attempts. Demographic, behavioral, and physical activity factors affect suicidal attempts mostly through depressive symptoms. In addition, there is a path that suggests that demographic, behavioral, and physical activity factors affect suicidal attempts not through depression symptoms but only through suicidal ideation. This means that the elderly who do not have depression symptoms attempt suicide according to their own situations and characteristics.

Effects of climate and lifeform on dry matter yield (epsilon) from simulations using BIOME BGC. [ecosystem process model for vegetation biomass production using daily absorbed photosynthetically active radiation

Science.gov (United States)

Hunt, E. R., Jr.; Running, Steven W.

1992-01-01

An ecosystem process simulation model, BIOME-BGC, is used in a sensitivity analysis to determine the factors that may cause the dry matter yield (epsilon) and annual net primary production to vary for different ecosystems. At continental scales, epsilon is strongly correlated with annual precipitation. At a single location, year-to-year variation in net primary production (NPP) and epsilon is correlated with either annual precipitation or minimum air temperatures. Simulations indicate that forests have lower epsilon than grasslands. The most sensitive parameter affecting forest epsilon is the total amount of living woody biomass, which affects NPP by increasing carbon loss by maintenance respiration. A global map of woody biomass should significantly improve estimates of global NPP using remote sensing.

The key factors affecting students' individual interest in school science lessons

Science.gov (United States)

Cheung, Derek

2018-01-01

Individual interest in school science lessons can be defined as a relatively stable and enduring personal emotion comprising affective and behavioural reactions to events in the regular science lessons at school. Little research has compared the importance of different factors affecting students' individual interest in school science lessons. The present study aimed to address this gap, using a mixed methods design. Qualitative interview data were collected from 60 Hong Kong junior secondary school students, who were asked to describe the nature of their interest in science lessons and the factors to which they attribute this. Teacher interviews, parent interviews, and classroom observations were conducted to triangulate student interview data. Five factors affecting students' individual interest in school science lessons were identified: situational influences in science lessons, individual interest in science, science self-concept, grade level, and gender. Quantitative data were then collected from 591 students using a questionnaire. Structural equation modelling was applied to test a hypothesised model, which provided an acceptable fit to the student data. The strongest factor affecting students' individual interest in school science lessons was science self-concept, followed by individual interest in science and situational influences in science lessons. Grade level and gender were found to be nonsignificant factors. These findings suggest that teachers should pay special attention to the association between academic self-concept and interest if they want to motivate students to learn science at school.

Methods for pretreating biomass

Science.gov (United States)

Balan, Venkatesh; Dale, Bruce E; Chundawat, Shishir; Sousa, Leonardo

2017-05-09

A method for pretreating biomass is provided, which includes, in a reactor, allowing gaseous ammonia to condense on the biomass and react with water present in the biomass to produce pretreated biomass, wherein reactivity of polysaccharides in the biomass is increased during subsequent biological conversion as compared to the reactivity of polysaccharides in biomass which has not been pretreated. A method for pretreating biomass with a liquid ammonia and recovering the liquid ammonia is also provided. Related systems which include a biochemical or biofuel production facility are also disclosed.

Evaluation of total aboveground biomass and total merchantable biomass in Missouri

Science.gov (United States)

Michael E. Goerndt; David R. Larsen; Charles D. Keating

2014-01-01

In recent years, the state of Missouri has been converting to biomass weight rather than volume as the standard measurement of wood for buying and selling sawtimber. Therefore, there is a need to identify accurate and precise methods of estimating whole tree biomass and merchantable biomass of harvested trees as well as total standing biomass of live timber for...

Source apportionment of air pollution exposures of rural Chinese women cooking with biomass fuels

Science.gov (United States)

Huang, Wei; Baumgartner, Jill; Zhang, Yuanxun; Wang, Yuqin; Schauer, James J.

2015-03-01

Particulate matter (PM) from different sources may differentially affect human health. Few studies have assessed the main sources of personal exposure to PM and their contributions among residents of developing countries, where pollution sources differ from those in higher-income settings. 116 daily (24-h) personal PM2.5 exposure samples were collected among 81 women cooking with biomass fuels in two villages in rural Yunnan, China. The PM samples were analyzed for mass and chemical composition, including water-soluble organic carbon (WSOC), black carbon (BC), and molecular markers. We found black carbon, n-alkanes and levoglucosan dominated the most abundant fractions of the total measured species and average personal PM2.5 exposure was higher in winter than that in summer in both villages. The composition data were then analyzed using a positive matrix factorization (PMF) receptor model to identify the main PM emission sources contributing to women's exposures and to assess their spatial (between villages) and seasonal variation in our study setting. The 6-factor solution provided reasonably stable profiles and was selected for further analysis. Our results show that rural Chinese women cooking with biomass fuels are exposed to a variety of sources. The identified factors include wood combustion (41.1%), a cooking source (35.6%), a mobile source (12.6%), plant waxes (6.7%), pyrolysis combustion (3.0%), and secondary organic aerosols (SOA; 1.0%). The mean source contributions of the mobile source, cooking source, and wood combustion factor to PM2.5 exposure were significantly different between women living in the two study villages, whereas the mean SOA, wood combustion, and plant waxes factors differed seasonally. There was no relationship between source contributions and questionnaire-based measurements of source-specific exposures, implying that the impacts of source contributions on exposure are affected by complex spatial, temporal and behavioral patterns

Evaluation of factors affecting adherence to asthma controller ...

African Journals Online (AJOL)

Evaluation of factors affecting adherence to asthma controller therapy in chest clinics in a sub-Saharan African setting: a cross-sectional study. ... Background: Adherence to controller therapy in asthma is a major concern during the management of the disease. Objective: To determine the adherence rate and identify the ...

Factors affecting mortality and epidemiological data in patients ...

African Journals Online (AJOL)

Background. Burns continue to be responsible for significant morbidity and mortality in developing countries. In this study we aimed to determine the factors affecting mortality and epidemiological data by examining the records of burned patients. Method. The hospital records of 980 patients who were hospitalised in the ...

Factors Affecting Students' Grades in Principles of Economics

Science.gov (United States)

Kara, Orhan; Bagheri, Fathollah; Tolin, Thomas

2009-01-01

Factors affecting students' grades in principles of microeconomics and macroeconomics students are analyzed from the data collected in two public universities. Results indicate that gender, number of hours worked, SAT scores, number of missed classes, recommending the course to a friend, instructors, being a junior, number of economics courses…

Factors affecting guidance and counseling programme in primary ...

African Journals Online (AJOL)

The objective of this study was to establish the factors that affect guidance and counseling in primary schools. Guidance and counseling seems not to be adequately helping pupils with physical and psychological problems in Nairobi province of Kenya. Many primary schools are faced with indiscipline and poor performance ...

Source apportionment of organic compounds in Berlin using positive matrix factorization - assessing the impact of biogenic aerosol and biomass burning on urban particulate matter.

Science.gov (United States)

Wagener, Sandra; Langner, Marcel; Hansen, Ute; Moriske, Heinz-Jörn; Endlicher, Wilfried R

2012-10-01

Source apportionment of 13 organic compounds, elemental carbon and organic carbon of ambient PM(10) and PM(1) was performed with positive matrix factorization (PMF). Samples were collected at three sites characterized by different vegetation influences in Berlin, Germany in 2010. The aim was to determine organic, mainly biogenic sources and their impact on urban aerosol collected in a densely populated region. A 6-factor solution provided the best data fit for both PM-fractions, allowing the sources isoprene- and α-pinene-derived secondary organic aerosol (SOA), bio primary, primarily attributable to fungal spores, bio/urban primary including plant fragments in PM(10) and cooking and traffic emissions in PM(1), biomass burning and combustion fossil to be identified. With mean concentrations up to 2.6 μg Cm(-3), biomass burning dominated the organic fraction in cooler months. Concentrations for α-pinene-derived SOA exceeded isoprene-derived concentrations. Estimated secondary organic carbon contributions to total organic carbon (OC) were between 7% and 42% in PM(10) and between 11% and 60% in PM(1), which is slightly lower than observed for US- or Asian cities. Primary biogenic emissions reached up to 33% of OC in the PM(10)-fraction in the late summer and autumn months. Temperature-dependence was found for both SOA-factors, correlations with ozone and mix depth only for the α-pinene-derived SOA-factor. Latter indicated input of α-pinene from the borders, highlighting differences in the origin of the precursors of both factors. Most factors were regionally distributed. High regional distribution was found to be associated with stronger influence of ambient parameters and higher concentrations at the background station. A significant contribution of biogenic emissions and biomass burning to urban organic aerosol could be stated. This indicates a considerable impact on PM concentrations also in cities in a densely populated area, and should draw the attention

DUE GlobBiomass - Estimates of Biomass on a Global Scale

Science.gov (United States)

Eberle, J.; Schmullius, C.

2017-12-01

For the last three years, a new ESA Data User Element (DUE) project had focussed on creating improved knowledge about the Essential Climate Variable Biomass. The main purpose of the DUE GlobBiomass project is to better characterize and to reduce uncertainties of AGB estimates by developing an innovative synergistic mapping approach in five regional sites (Sweden, Poland, Mexico, Kalimantan, South Africa) for the epochs 2005, 2010 and 2015 and for one global map for the year 2010. The project team includes leading Earth Observation experts of Europe and is linked through Partnership Agreements with further national bodies from Brazil, Canada, China, Russia and South Africa. GlobBiomass has demonstrated how EO observation data can be integrated with in situ measurements and ecological understanding to provide improved biomass estimates that can be effectively exploited by users. The target users had mainly be drawn from the climate and carbon cycle modelling communities and included users concerned with carbon emissions and uptake due to biomass changes within initiatives such as REDD+. GlobBiomass provided a harmonised structure that can be exploited to address user needs for biomass information, but will be capable of being progressively refined as new data and methods become available. This presentation will give an overview of the technical prerequisites and final results of the GlobBiomass project.

The role of phytoplankton composition, biomass and cell volume in accumulation and transfer of endocrine disrupting compounds in the Southern Baltic Sea (The Gulf of Gdansk)

International Nuclear Information System (INIS)

Staniszewska, Marta; Nehring, Iga; Zgrundo, Aleksandra

2015-01-01

Endocrine disrupting compounds (EDCs) like bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) are introduced to the trophic webs through among others phytoplankton. This paper describes BPA, OP and NP concentrations in phytoplankton in the Gulf of Gdansk (Southern Baltic Sea) in the years 2011–2012. The assays of BPA, OP and NP in samples were performed using HPLC with fluorescence detection. The concentrations of BPA, the most commonly used of the three compounds, were over ten times higher than OP and NP concentrations. The concentrations of the studied EDCs in phytoplankton from the Gulf of Gdansk depended on anthropogenic factors and on phytoplankton properties (species composition, biomass, volume). An increase in phytoplankton biomass did not always result in an increase of BPA, OP and NP concentrations. However, the load of the studied EDCs accumulated in phytoplankton biomass increase with a rise of biomass. An increase in BPA, OP and NP concentrations was effected by biomass growth and the proportions ofciliates, dinoflagellates, diatoms and green algae. A strong positive correlation between OP and NP concentrations and negative correlation between BPA concentrations and biomass of organisms with cells measuring <1000 μm"3 in volume results from the differing properties of these compounds. - Highlights: • The concentration of BPA was higher than OP, NP in phytoplankton. • The concentration of BPA, OP, NP depended on phytoplankton properties. • The load of BPA, OP, NP accumulated with phytoplankton increase with a rise of the biomass. • Ciliates, dinoflagellates, diatoms, green algae accumulated the most BPA, OP, NP. • Higher biomass of smaller volume organisms more accumulated OP, NP and less BPA. - The study has shown that factors affecting concentration of BPA, NP and OP were: species composition, biomass, volume and location of sampling station.

Factors affecting e-Commerce adoption in Danish and Australian SMEs

DEFF Research Database (Denmark)

Scupola, Ada

2006-01-01

This paper presents the results of a study investigating environmental, organizational and technological factors influencing adoption of electronic commerce in small and medium size enterprises in Denmark and Australia. A total of eight companies have been interviewd, four located in the area....... The main organizational factors affecting e-commerce adoption in the two countries are the CEO and employees' knowledge and attitude. Finally a number of technology related factors affect e-commerce adoption in the two countries as for example the ability to stream information out to the clients...... of Copenhagen, Denamrk and four in Brisbane area, Australia. The results show many interesting similarities and few differences between the two countries. For example, in both countries the external environment has an influence mainly through customer pressure and availability of ICT consulting services...

An overview of particulate emissions from residential biomass combustion

Science.gov (United States)

Vicente, E. D.; Alves, C. A.

2018-01-01

Residential biomass burning has been pointed out as one of the largest sources of fine particles in the global troposphere with serious impacts on air quality, climate and human health. Quantitative estimations of the contribution of this source to the atmospheric particulate matter levels are hard to obtain, because emission factors vary greatly with wood type, combustion equipment and operating conditions. Updated information should improve not only regional and global biomass burning emission inventories, but also the input for atmospheric models. In this work, an extensive tabulation of particulate matter emission factors obtained worldwide is presented and critically evaluated. Existing quantifications and the suitability of specific organic markers to assign the input of residential biomass combustion to the ambient carbonaceous aerosol are also discussed. Based on these organic markers or other tracers, estimates of the contribution of this sector to observed particulate levels by receptor models for different regions around the world are compiled. Key areas requiring future research are highlighted and briefly discussed.

Factors affecting the HIV/AIDS epidemic: An ecological analysis of ...

African Journals Online (AJOL)

Factors affecting the HIV/AIDS epidemic: An ecological analysis of global data. ... Backward multiple linear regression analysis identified the proportion of Muslims, physicians density, and adolescent fertility rate are as the three most prominent factors linked with the national HIV epidemic. Conclusions: The findings support ...

Factors Affecting Adoption of Recommended Cauliflower Production Technology in Nepal

Directory of Open Access Journals (Sweden)

Pankaj Raj Dhital

2016-05-01

Full Text Available Binary logit regression model of econometrics was used to identify the factors affecting adoption of recommended agricultural technology by the commercial farmers of Nepal. A survey was carried out in 2012 in 120 households from Kavre district, Nepal. The objective was to appraise factors affecting adoption of recommended technology of cauliflower, finding out the level of adoption, identifying the constraints of cauliflower cultivation, assessing the perceived level of satisfaction and studying the relationship of certain selected variables on the adoption. Education, Occupation, contact with Personal Localite sources of information, Group membership and Experience were the most influencing factors for adoption of recommended technology. Though, other factors were not strong enough to contribute significantly but indirectly influence the adoption decision of farmers as combined effects. Occupation was found as negatively associated. Landholding size was strongly and positively influencing among the non significant factors. The level of satisfaction and the constraints of cauliflower production were also identified. Transfer of technology will be effective if and only if the client adopts the technology. For an effective transfer of technology, it is better to go for activities for the welfare of the socioeconomic factors of the farmers.

Multiple factors affecting South African anchovy recruitment in the ...

African Journals Online (AJOL)

Multiple factors affecting South African anchovy recruitment in the spawning, transport and nursery. ... and are inversely linked to high rates of gonad atresia in anchovy and reduced subsequent recruitment. ... AJOL African Journals Online.

Biomass torrefaction mill

Science.gov (United States)

Sprouse, Kenneth M.

2016-05-17

A biomass torrefaction system includes a mill which receives a raw biomass feedstock and operates at temperatures above 400 F (204 C) to generate a dusty flue gas which contains a milled biomass product.

Biomass Accumulation, Photosynthetic Traits and Root Development of Cotton as Affected by Irrigation and Nitrogen-Fertilization

Directory of Open Access Journals (Sweden)

Zongkui Chen

2018-02-01

Full Text Available Limitations of soil water and nitrogen (N are factors which cause a substantial reduction in cotton (Gossypium hirsutum L. yield, especially in an arid environment. Suitable management decisions like irrigation method and nitrogen fertilization are the key yield improvement technologies in cotton production systems. Therefore, we hypothesized that optimal water-N supply can increase cotton plant biomass accumulation by maintaining leaf photosynthetic capacity and improving root growth. An outdoor polyvinyl chloride (PVC tube study was conducted to investigate the effects of two water-N application depths, i.e., 20 cm (H20 or 40 cm (H40 from soil surface and four water-N combinations [deficit irrigation (W55 and no N (N0 (W55N0, W55 and moderate N (N1 (W55N1, moderate irrigation (W75 and N0 (W75N0, W75N1] on the roots growth, leaf photosynthetic traits and dry mass accumulation of cotton crops. H20W55N1 combination increased total dry mass production by 29–82% and reproductive organs biomass by 47–101% compared with other counterparts. Root protective enzyme and nitrate reductase (NR activity, potential quantum yield of photosystem (PS II (Fv/Fm, PSII quantum yield in the light [Y(II] and electron transport rate of PSII were significantly higher in H20W55N1 prior to 82 days after emergence. Root NR activity and protective enzyme were significantly correlated with chlorophyll, Fv/Fm, Y(II and stomatal conductance. Hence, shallow irrigation (20 cm with moderate irrigation and N-fertilization application could increase cotton root NR activity and protective enzyme leading to enhance light capture and photochemical energy conversion of PSII before the full flowering stage. This enhanced photoassimilate to reproductive organs.

Genetic factors affecting dental caries risk.

Science.gov (United States)

Opal, S; Garg, S; Jain, J; Walia, I

2015-03-01

This article reviews the literature on genetic aspects of dental caries and provides a framework for the rapidly changing disease model of caries. The scope is genetic aspects of various dental factors affecting dental caries. The PubMed database was searched for articles with keywords 'caries', 'genetics', 'taste', 'diet' and 'twins'. This was followed by extensive handsearching using reference lists from relevant articles. The post-genomic era will present many opportunities for improvement in oral health care but will also present a multitude of challenges. We can conclude from the literature that genes have a role to play in dental caries; however, both environmental and genetic factors have been implicated in the aetiology of caries. Additional studies will have to be conducted to replicate the findings in a different population. Identification of genetic risk factors will help screen and identify susceptible patients to better understand the contribution of genes in caries aetiopathogenesis. Information derived from these diverse studies will provide new tools to target individuals and/or populations for a more efficient and effective implementation of newer preventive measures and diagnostic and novel therapeutic approaches in the management of this disease. © 2015 Australian Dental Association.

Factors affecting scholastic performances of adolescents.

Science.gov (United States)

Shashidhar, Saraswati; Rao, Chandrika; Hegde, Radhakrishna

2009-05-01

The present study aims at recognizing the social influence, study habits and health factors affecting scholastic performances of adolescents and to compare these factors among the adolescents between two categories of school. A total of 1230 adolescents (13-18 yrs) were screened. Data was collected by personal interview, using the teenage screening questionnaire, Trivandrum, between May 2004 and November 2005. A total 615 students from corporation and private schools were studied. 39.76% (489) were high achievers, 13.5% (166) were low achievers with p poor study habits and social factors were increased in low achievers of corporation schools. On multivariate analysis, the predictor variables for poor scholastic performance were adolescent having refractory error, not having help for study at home, not doing home work regularly, not solving question bank papers and reading only before examinations. It is feasible and worthwhile to identify the determinants of scholastic performance and plan intervention strategies at each school. The results of this study highlight the importance of implementing newer strategies, focusing on strict study patterns and creating the conducive school and home environment for study, so as to achieve better scholastic performances.

The Spatial Distribution of Forest Biomass in the Brazilian Amazon: A Comparison of Estimates

Science.gov (United States)

Houghton, R. A.; Lawrence, J. L.; Hackler, J. L.; Brown, S.

2001-01-01

The amount of carbon released to the atmosphere as a result of deforestation is determined, in part, by the amount of carbon held in the biomass of the forests converted to other uses. Uncertainty in forest biomass is responsible for much of the uncertainty in current estimates of the flux of carbon from land-use change. We compared several estimates of forest biomass for the Brazilian Amazon, based on spatial interpolations of direct measurements, relationships to climatic variables, and remote sensing data. We asked three questions. First, do the methods yield similar estimates? Second, do they yield similar spatial patterns of distribution of biomass? And, third, what factors need most attention if we are to predict more accurately the distribution of forest biomass over large areas? Amazonian forests (including dead and below-ground biomass) vary by more than a factor of two, from a low of 39 PgC to a high of 93 PgC. Furthermore, the estimates disagree as to the regions of high and low biomass. The lack of agreement among estimates confirms the need for reliable determination of aboveground biomass over large areas. Potential methods include direct measurement of biomass through forest inventories with improved allometric regression equations, dynamic modeling of forest recovery following observed stand-replacing disturbances (the approach used in this research), and estimation of aboveground biomass from airborne or satellite-based instruments sensitive to the vertical structure plant canopies.

The effects of location, feedstock availability, and supply-chain logistics on the greenhouse gas emissions of forest-biomass energy utilization in Finland

Energy Technology Data Exchange (ETDEWEB)

Jappinen, E,

2013-11-01

Forest biomass represents a geographically distributed feedstock, and geographical location affects the greenhouse gas (GHG) performance of a given forest-bioenergy system in several ways. For example, biomass availability, forest operations, transportation possibilities and the distances involved, biomass end-use possibilities, fossil reference systems, and forest carbon balances all depend to some extent on location. The overall objective of this thesis was to assess the GHG emissions derived from supply and energy-utilization chains of forest biomass in Finland, with a specific focus on the effect of location in relation to forest biomass's availability and the transportation possibilities. Biomass availability and transportation-network assessments were conducted through utilization of geographical information system methods, and the GHG emissions were assessed by means of lifecycle assessment. The thesis is based on four papers in which forest biomass supply on industrial scale was assessed. The feedstocks assessed in this thesis include harvesting residues, smalldiameter energy wood and stumps. The principal implication of the findings in this thesis is that in Finland, the location and availability of biomass in the proximity of a given energyutilization or energy-conversion plant is not a decisive factor in supply-chain GHG emissions or the possible GHG savings to be achieved with forest-biomass energy use. Therefore, for the greatest GHG reductions with limited forest-biomass resources, energy utilization of forest biomass in Finland should be directed to the locations where most GHG savings are achieved through replacement of fossil fuels. Furthermore, one should prioritize the types of forest biomass with the lowest direct supply-chain GHG emissions (e.g., from transport and comminution) and the lowest indirect ones (in particular, soil carbon-stock losses), regardless of location. In this respect, the best combination is to use harvesting residues

Factors affecting sustainability of rural water schemes in Swaziland

Science.gov (United States)

Peter, Graciana; Nkambule, Sizwe E.

The Millennium Development Goal (MDG) target to reduce the proportion of people without sustainable access to safe drinking water by the year 2015 has been met as of 2010, but huge disparities exist. Some regions, particularly Sub-Saharan Africa are lagging behind it is also in this region where up to 30% of the rural schemes are not functional at any given time. There is need for more studies on factors affecting sustainability and necessary measures which when implemented will improve the sustainability of rural water schemes. The main objective of this study was to assess the main factors affecting the sustainability of rural water schemes in Swaziland using a Multi-Criteria Analysis Approach. The main factors considered were: financial, social, technical, environmental and institutional. The study was done in Lubombo region. Fifteen functional water schemes in 11 communities were studied. Data was collected using questionnaires, checklist and focused group discussion guide. A total of 174 heads of households were interviewed. Statistical Package for Social Sciences (SPSS) was used to analyse the data and to calculate sustainability scores for water schemes. SPSS was also used to classify sustainability scores according to sustainability categories: sustainable, partially sustainable and non-sustainable. The averages of the ratings for the different sub-factors studied and the results on the sustainability scores for the sustainable, partially sustainable and non-sustainable schemes were then computed and compared to establish the main factors influencing sustainability of the water schemes. The results indicated technical and social factors as most critical while financial and institutional, although important, played a lesser role. Factors which contributed to the sustainability of water schemes were: functionality; design flow; water fetching time; ability to meet additional demand; use by population; equity; participation in decision making on operation and

Factors Affecting Behaviours that address HIV Risk among Nigerian ...

African Journals Online (AJOL)

Objective: The aim of this study was to identify factors affecting HIV risk reduction ... Main outcome measures: Sexual behavior and condom use, knowledge about ... attitudes, normative beliefs, and subjective norms about condoms, HIV/AIDS ...

Factors Affecting the Efficiency of Maize Marketing in Vandeikya ...

African Journals Online (AJOL)

Factors Affecting the Efficiency of Maize Marketing in Vandeikya Local Government Area of Benue State, Nigeria. ... Two hundred maize marketers were selected from Vandeikya Local Area (LGA) of ... EMAIL FULL TEXT EMAIL FULL TEXT

The potential impact of externalities considerations on the market for biomass power technologies

International Nuclear Information System (INIS)

Swezey, B.G.; Porter, K.L.; Feher, J.S.

1995-01-01

Of all the renewable energy sources used for power generation, biomass energy has experienced the greatest growth over the last decade. Spurred by requirements established in the Public Utility Regulatory Policies Act of 1978 (PURPA), as well as various tax incentives, biomass-based power generation now provides more than 50 billion kWh of electric energy from 10,000 MW of installed capacity. The overwhelming majority of this capacity, primarily wood-based, has been developed by the nonutility sector. However, the biomass industry is currently facing more difficult market conditions due to a reduction in federal incentives and changes in the generation market, such as lower utility avoided costs, slower demand growth, and greater competition among both generators and fuel sources. States are increasingly contemplating the inclusion of market externalities costs and benefits associated with different generation options in electricity resource planning and procurement decisions. Market externalities, as they relate to generation resources and technologies, represent impacts that are not wholly reflected in the market price of electricity derived from these sources. These impacts, which can be either positive or negative, can encompass environmental, economic and other social factors, but state considerations have focused predominantly on environmental externalities costs, especially air emissions. The explicit quantification of externalities could measurably affect the competitive standing of various energy resources and technologies in future generation resource acquisitions. This paper summarizes work undertaken to assess the status the externalities considerations in state and utility electricity resource planning processes and to determine how externalities considerations might help or hinder future development of biomass power plants. (author)

Identifying factors affecting about outsourcing in paraclinical services

African Journals Online (AJOL)

Objective: Outsourcing refers to the transfer of services or functions to an outsider supplier, which controls them through a contract or cooperative. The main problem of senior managers in health organizations is determining the services which should be outsourced. The present study seeks to identify the factors that affect ...

Factors Affecting Online Groupwork Interest: A Multilevel Analysis

Science.gov (United States)

Du, Jianxia; Xu, Jianzhong; Fan, Xitao

2013-01-01

The purpose of the present study is to examine the personal and contextual factors that may affect students' online groupwork interest. Using the data obtained from graduate students in an online course, both student- and group-level predictors for online groupwork interest were analyzed within the framework of hierarchical linear modeling…

Factors affecting sustainable animal trypanosomosis control in parts ...

African Journals Online (AJOL)

This study examined the factors affecting sustainable trypanosomiasis control in parts of Kaduna State within the sub-humid savannah ecological zone of Nigeria. Focus group discussions were ... More awareness and preference for pour-on and aerial spraying were higher than the use of traps, target or screens. Rearing of ...

Energy from biomass: An overview. Energie uit biomassa: Een overzicht

Energy Technology Data Exchange (ETDEWEB)

Van der Toorn, L J; Elliott, T P [Non-Traditional Business Division, Shell International Petroleum Company, London (United Kingdom)

1992-03-01

Attention is paid to the effect of the use of energy from biomass on the greenhouse effect. An overview is given of the aspects of forest plantation, carbon dioxide fixation and energy from biomass, in particular with regard to the potential impact of the use of biomass energy on the speed of accumulation of carbon in the atmosphere. A simple model of the carbon cycle to illustrate the geochemical, biological and antropogenic characteristics of the cycle is presented and briefly discussed. Biomass, which is appropriate for energy applications, can be subdivided into three categories: polysaccharides, vegetable oils, and lignocellulosis. The costs for the latter are discussed. Three important options to use biomass as a commercial energy source are solid fuels, liquid fuels, and power generation. For each option the value of energy (on a large-scale level) is compared to the costs of several types of biomass. Recent evaluation of new techniques show that small biomass conversion plants can realize an electricity efficiency of 40%, with capitalized costs far below comparable conventional biomass conversion plants. One of the policy instruments to stimulate the use of biomass as an energy source is the carbon levy, in which the assumed external costs to reduce carbon dioxide emission are expressed. Political and administrative feasibility are important factors in the decision making with regard to carbon storage and energy plantations. 6 figs.

Does warming affect growth rate and biomass production of shrubs in the High Arctic?

DEFF Research Database (Denmark)

Campioli, Matteo; Schmidt, Niels Martin; Albert, Kristian Rost

2013-01-01

Few studies have assessed directly the impact of warming on plant growth and biomass production in the High Arctic. Here, we aimed to investigate the impact of 7 years of warming (open greenhouses) on the aboveground relative growth rate (RGR) of Cassiope tetragona and Salix arctica in North-East...

Global Factors that Affect the Real Estate Markets in the EU

Directory of Open Access Journals (Sweden)

Povilas Švogžlys

2016-06-01

Full Text Available The place, neighbourhood, infrastructure, and apartment plan are the main factors which have an influence on price for the buyers, sellers, investors, or brokers participating in the buying and selling processes of real estate. Participants of the process forget frequently that there are more crucial factors which can affect not only the prices of property, but the prices of real estate in the whole region as well in the future. The article uses benchmarking and discuss the main external factors which affect the real estate market in the European Union, the current events and the proposals are presented and the specific conclusions are identified.

Socioeconomic Factors Affecting Adoption of Sunflower Varieties in Sindh

Directory of Open Access Journals (Sweden)

Ghulam Ali Jariko (Corresponding Author

2011-09-01

Full Text Available This research study is based on primary data collection from sunflower growers to assess the socioeconomic factors that are affecting the adoption of sunflower varieties in Sindh.Data samples have been selected from two districts; Badin and Thatta, as these districts are considered main sunflower growing areas in Sindh. The results reveal that Sunflower growers are using Hybrid varieties i.e. 43 percent planted Hysun-33, 29 percent Hysun-38 and 28 percent Hysun-37 varieties. The finding of research using multinomial logistic regression suggests that farm size and level of education significantly affected the adoption of sunflower varieties. These factors are statistically significant at p<0.05. Theother variables such as tenancy status and source of income are not statistically significant in the adoption of sunflower varieties in Sindh.

Methods for producing and using densified biomass products containing pretreated biomass fibers

Science.gov (United States)

Dale, Bruce E.; Ritchie, Bryan; Marshall, Derek

2015-05-26

A process is provided comprising subjecting a quantity of plant biomass fibers to a pretreatment to cause at least a portion of lignin contained within each fiber to move to an outer surface of said fiber, wherein a quantity of pretreated tacky plant biomass fibers is produced; and densifying the quantity of pretreated tacky plant biomass fibers to produce one or more densified biomass particulates, wherein said biomass fibers are densified without using added binder.

Bioadsorption of nickel Mining Company by residual biomass Phyllanthus Orbicularis

Directory of Open Access Journals (Sweden)

Ariel Díaz-Puig

2017-01-01

Full Text Available Kinetic parameters for the adsorption of nickel were studied in the waste CalcinationPlant Company Ernesto Che Guevara biomass Phyllanthus orbicularis synthetic and industrial waste Calcination Plant enterprise solutions. The results showed that the major factors influencing the adsorption capacity of the biomass increases with increasing pH and the initial concentration of nickel in the effluent and is reduced by increasing the biomass concentration. Meanwhile, the removal efficiency of residual nickel increases with increasing pH and concentration of biomass and reduced when the initial concentration of nickel in the effluent increases. The adsorption capacity nickel biomass Phyllanthus orbicularis from synthetic solutions and industrial waste Calcination Plant Company Nickel "Comandante Ernesto Che Guevara" was 44,05 and 26,25 mg/g respectively. The adsorption process nickel biomass Phyllanthus orbicularis follows kinetics pseudo-second order and according to the values of free energy of adsorption obtained through model-RadushkevichDubinin was 267,26 kJ/mol, this nature demonstrates that corresponds to a process mediated by chemical adsorption where the formation of stable bonds between the functional groups present in the biomass and the metal ions predominates.

Factors affecting extension workers in their rendering of effective ...

African Journals Online (AJOL)

Factors affecting extension workers in their rendering of effective service to pre and ... Small, micro and medium entrepreneurs play an important role in economic ... such as production, marketing and management to adequately service the ...

Factors affecting virus dynamics and microbial host-virus interactions in marine environments

NARCIS (Netherlands)

Mojica, K.D.A.; Brussaard, C.P.D.

2014-01-01

Marine microorganisms constitute the largest percentage of living biomass and serve as the major driving force behind nutrient and energy cycles. While viruses only comprise a small percentage of this biomass (i.e., 5%), they dominate in numerical abundance and genetic diversity. Through host

Factors affecting the periapical healing process of endodontically treated teeth

Directory of Open Access Journals (Sweden)

Roberto Holland

Full Text Available Abstract Tissue repair is an essential process that reestablishes tissue integrity and regular function. Nevertheless, different therapeutic factors and clinical conditions may interfere in this process of periapical healing. This review aims to discuss the important therapeutic factors associated with the clinical protocol used during root canal treatment and to highlight the systemic conditions associated with the periapical healing process of endodontically treated teeth. The antibacterial strategies indicated in the conventional treatment of an inflamed and infected pulp and the modulation of the host's immune response may assist in tissue repair, if wound healing has been hindered by infection. Systemic conditions, such as diabetes mellitus and hypertension, can also inhibit wound healing. The success of root canal treatment is affected by the correct choice of clinical protocol. These factors are dependent on the sanitization process (instrumentation, irrigant solution, irrigating strategies, and intracanal dressing, the apical limit of the root canal preparation and obturation, and the quality of the sealer. The challenges affecting the healing process of endodontically treated teeth include control of the inflammation of pulp or infectious processes and simultaneous neutralization of unpredictable provocations to the periapical tissue. Along with these factors, one must understand the local and general clinical conditions (systemic health of the patient that affect the outcome of root canal treatment prediction.

The biomass file

International Nuclear Information System (INIS)

2010-01-01

As biomass represents the main source of renewable energy to reach the 23 per cent objective in terms of energy consumption by 2020, a first article gives a synthetic overview of its definition, its origins, its possible uses, its share in the French energy mix, its role by 2020, strengths and weaknesses for its development, the growth potential of its market, and its implications in terms of employment. A second article outlines the assets of biomass, indicates the share of some crops in biomass energy production, and discusses the development of new resources and the possible energy valorisation of various by-products. Interviews about biomass market and development perspectives are proposed with representatives of institutions, energy industries and professional bodies concerned with biomass development and production. Other articles comments the slow development of biomass-based cogeneration, the coming into operation of a demonstration biomass roasting installation in Pau (France), the development potential of biogas in France, the project of bio natural gas vehicles in Lille, and the large development of biogas in Germany

A Thermogravimetric Study of the Behaviour of Biomass Blends During Combustion

Directory of Open Access Journals (Sweden)

Ivo Jiříček

2012-01-01

Full Text Available The ignition and combustion behavior of biomass and biomass blends under typical heating conditions were investigated. Thermogravimetric analyses were performed on stalk and woody biomass, alone and blended with various additive weight ratios. The combustion process was enhanced by adding oxygen to the primary air. This led to shorter devolatilization/pyrolysis and char burnout stages, which both took place at lower temperatures than in air alone. The results of the ignition study of stalk biomass show a decrease in ignition temperature as the particle size decreases. This indicates homogeneous ignition, where the volatiles burn in the gas phase, preventing oxygen from reaching the particle surface.The behavior of biomass fuels in the burning process was analyzed, and the effects of heat production and additive type were investigated. Mixing with additives is a method for modifying biofuel and obtaining a more continuous heat release process. Differential scanning calorimetric-thermogravimetric (DSC-TGA analysis revealed that when the additive is added to biomass, the volatilization rate is modified, the heat release is affected, and the combustion residue is reduced at the same final combustion temperature.

Emergency Nurses' Perspectives: Factors Affecting Caring.

Science.gov (United States)

Enns, Carol L; Sawatzky, Jo-Ann V

2016-05-01

Caring is a universal phenomenon. However, as a result of higher patient acuity and staff shortages within the chaotic ED environment, caring behaviors may be in peril. The purpose of this study was to gain insight into the meaning of caring from the perspective of emergency nurses. Exploring nurses' perspectives of caring is central to improving staffing and retention issues in this unique work environment. As part of a larger study, a subsample of emergency nurses who work in public hospitals in Manitoba, Canada (n = 17) were interviewed. A qualitative descriptive design was used to gain insight into the caring perspectives of nurses by asking them, "What does caring meaning to you?" and "What affects caring in your practice in the emergency department?" Emerging themes were extracted through analysis of audio tapes and transcripts. Advocacy and holistic care emerged as major themes in the meaning of caring for emergency nurses. Caring was affected by a number of factors, including workload, lack of time, staffing issues, shift work, and lack of self-care. However, lack of management support was the most consistent hindrance to caring identified by study participants. Caring continues to be a unifying concept in nursing; however, influencing factors continue to undermine caring for emergency nurses. Caring is not subsidiary to nursing; it is the central core of nursing. Therefore, fostering a caring working environment is essential for nurses to practice holistic nursing care. It is also imperative to job satisfaction and the retention of emergency nurses. Copyright © 2016 Emergency Nurses Association. Published by Elsevier Inc. All rights reserved.

Some factors that will affect the next generation of forest growth models

International Nuclear Information System (INIS)

Leary, R.A.

1988-01-01

This paper discusses several types of factors that affect the form and referents of future growth models. These include philosophical, scientific, technological, educational, and organizational factors. Each factor is presented individually

Biomass and pigments production in photosynthetic bacteria wastewater treatment: effects of light sources.

Science.gov (United States)

Zhou, Qin; Zhang, Panyue; Zhang, Guangming

2015-03-01

This study is aimed at enhancing biomass and pigments production together with pollution removal in photosynthetic bacteria (PSB) wastewater treatment via different light sources. Red, yellow, blue, white LED and incandescent lamp were used. Results showed different light sources had great effects on the PSB. PSB had the highest biomass production, COD removal and biomass yield with red LED. The corresponding biomass, COD removal and biomass yield reached 2580 mg/L, 88.6% and 0.49 mg-biomass/mg-COD-removal, respectively. The hydraulic retention time of wastewater treatment could be shortened to 72 h with red LED. Mechanism analysis showed higher ATP was produced with red LED than others. Light sources could significantly affect the pigments production. The pigments productions were greatly higher with LED than incandescent lamp. Yellow LED had the highest pigments production while red LED produced the highest carotenoid/bacteriochlorophyll ratio. Considering both efficiency and energy cost, red LED was the optimal light source. Copyright © 2014 Elsevier Ltd. All rights reserved.

Factors affecting outcome in ocular myasthenia gravis.

Science.gov (United States)

Mazzoli, Marco; Ariatti, Alessandra; Valzania, Franco; Kaleci, Shaniko; Tondelli, Manuela; Nichelli, Paolo F; Galassi, Giuliana

2018-01-01

50%-60% of patients with ocular myasthenia gravis (OMG) progress to generalized myasthenia gravis (GMG) within two years. The aim of our study was to explore factors affecting prognosis of OMG and to test the predictive role of several independent clinical variables. We reviewed a cohort of 168 Caucasian patients followed from September 2000 to January 2016. Several independent variables were considered as prognostic factors: gender, age of onset, results on electrophysiological tests, presence and level of antibodies against acetylcholine receptors (AChR Abs), treatments, thymic abnormalities. The primary outcome was the progression to GMG and/or the presence of bulbar symptoms. Secondary outcomes were either achievement of sustained minimal manifestation status or worsening in ocular quantitative MG subscore (O-QMGS) or worsening in total QMG score (T-QMGS), assessed by Myasthenia Gravis Foundation of America (MGFA) quantitative scores. Changes in mental and physical subscores of health-related quality of life (HRQoL) were assessed with SF-36 questionnaire. Variance analysis was used to interpret the differences between AChR Ab titers at different times of follow up among the generalized and non-generalized patients. Conversion to GMG occurred in 18.4% of patients; it was significantly associated with sex, later onset of disease and anti-AChR Ab positivity. Antibody titer above the mean value of 25.8 pmol/mL showed no significant effect on generalization. Sex and late onset of disease significantly affected T-QMGS worsening. None of the other independent variables significantly affected O-QMGS and HRQoL. Sex, later onset and anti-AChR Ab positivity were significantly associated with clinical worsening.

Environmental Factors Affecting the Whale Shark Aggregation site in the South Central Red Sea

KAUST Repository

Hozumi, Aya

2015-12-01

Motivation behind the spring whale shark (Rhincodon typus) aggregation in Al-Lith, on the Saudi Arabian coast of the South Central Red Sea, is uncertain. A plausible hypothesis is that whale sharks gather to feed on high prey density, leading to questions about the cause of the prey density. A bottom-up process fueled by nutrient input or accumulation from physical advection could create a peak in prey biomass. Wastewater discharged from an aquaculture facility could affect productivity or provide a chemosensory cue for whale sharks. Yet, basic physico-biological oceanography of this region is unresolved. Monthly profiles, long-term moorings, and spatial surveys were used to describe the temporal variability of potential prey biomass and water masses in this region for the first time. Plankton abundance of individuals larger than ~0.7 cm did not peak during whale shark season. Rather, a decrease coinciding the trailing end of whale shark detections was observed. Sites 180 m apart had differences in acoustic backscatter, suggesting small-scale biomass patchiness, supporting the small-scale variability in whale shark habitat selectivity. Red Sea Deep Water, a nutrient-rich water mass formed in the northern Red Sea, appeared in July at the same time the Tokar wind jet from the Sudanese mountain gap is the highest. Gulf of Aden Water, a nutrient-rich water mass from the Indian Ocean, arrived as episodes from May to September, contrary to previous expectations that the water arrives continuously. It is unlikely that these natural nutrient sources are directly responsible for the high prey density attracting the whale sharks. The aquaculture plume, observed at the aggregation site, had a distinct seasonality from the ambient waters. The plume’s highest salinity (>48) approached the extreme limits of coral tolerances. Nutrient concentrations (nitrate, nitrite, phosphate, silica), suspended particulate matter, phytoplankton biomass, bacteria and cyanobacteria cell counts

Energy production from biomass

International Nuclear Information System (INIS)

Bestebroer, S.I.

1995-01-01

The aim of the task group 'Energy Production from Biomass', initiated by the Dutch Ministry of Economic Affairs, was to identify bottlenecks in the development of biomass for energy production. The bottlenecks were identified by means of a process analysis of clean biomass fuels to the production of electricity and/or heat. The subjects in the process analysis are the potential availability of biomass, logistics, processing techniques, energy use, environmental effects, economic impact, and stimulation measures. Three categories of biomass are distinguished: organic residual matter, imported biomass, and energy crops, cultivated in the Netherlands. With regard to the processing techniques attention is paid to co-firing of clean biomass in existing electric power plants (co-firing in a coal-fired power plant or co-firing of fuel gas from biomass in a coal-fired or natural gas-fired power plant), and the combustion or gasification of clean biomass in special stand-alone installations. 5 figs., 13 tabs., 28 refs

Biomass Characterization | Bioenergy | NREL

Science.gov (United States)

Characterization Biomass Characterization NREL provides high-quality analytical characterization of biomass feedstocks, intermediates, and products, a critical step in optimizing biomass conversion clear, amber liquid Standard Biomass Laboratory Analytical Procedures We maintain a library of

Factors that affect the accuracy in the precise radiotherapy for abdomen tumors

International Nuclear Information System (INIS)

Yang Tieming; Ju Yongjian

2008-01-01

The precise radiotherapy has been widely used in the clinics. But there are many factors that affect the accuracy in the course of implementation. Finally the effect of radiotherapy is affected. These factors are reviewed. And the previous research data about the abdomen tumors is summed up. Also how the accuracy was affected by the respiratory movement, positioning, position fixed technology, weight, retraction and motion of the tumor and the situation of surrounding organs will be analyzed. At last, how to avoid these errors in clinics will be discussed. (authors)

Unemployment in Kenya: Some economic factors affecting wage ...

African Journals Online (AJOL)

This article analyses the economic factors affecting wage employment in Kenya, where open unemployment fell from 15 per cent in 1998/1999 to 13 per cent in 2005/2006. As of 2005/2006, wage employment constituted 13 per cent of the total working population, which implies that doubling wage employment will absorb ...

Factors affecting sports participation among female students at ...

African Journals Online (AJOL)

The primary aim of this study was to examine factors affecting sport participation among resident and non- resident female students at Tshwane University of Technology (TUT), Pretoria, South Africa. The study targeted all students participating in 12 registered sports but due to the fact that only a limited number of the total ...

Factors affecting sexual function in menopause: A review article

Directory of Open Access Journals (Sweden)

Soheila Nazarpour

2016-08-01

Full Text Available This study aimed to systematically review the articles on factors affecting sexual function during menopause. Searching articles indexed in Pubmed, Science Direct, Iranmedex, EMBASE, Scopus, and Scientific Information Database databases, a total number of 42 studies published between 2003 and 2013 were selected. Age, estrogen deficiency, type of menopause, chronic medical problems, partner's sex problems, severity of menopause symptoms, dystocia history, and health status were the physical factors influencing sexual function of menopausal women. There were conflicting results regarding the amount of androgens, hormonal therapy, exercise/physical activity, and obstetric history. In the mental–emotional area, all studies confirmed the impact of depression and anxiety. Social factors, including smoking, alcohol consumption, the quality of relationship with husband, partner's loyalty, sexual knowledge, access to health care, a history of divorce or the death of a husband, living apart from a spouse, and a negative understanding of women's health were found to affect sexual function; however, there were conflicting results regarding the effects of education, occupation, socioeconomic status, marital duration, and frequency of sexual intercourse.

Factors affecting sexual function in menopause: A review article.

Science.gov (United States)

Nazarpour, Soheila; Simbar, Masoumeh; Tehrani, Fahimeh Ramezani

2016-08-01

This study aimed to systematically review the articles on factors affecting sexual function during menopause. Searching articles indexed in Pubmed, Science Direct, Iranmedex, EMBASE, Scopus, and Scientific Information Database databases, a total number of 42 studies published between 2003 and 2013 were selected. Age, estrogen deficiency, type of menopause, chronic medical problems, partner's sex problems, severity of menopause symptoms, dystocia history, and health status were the physical factors influencing sexual function of menopausal women. There were conflicting results regarding the amount of androgens, hormonal therapy, exercise/physical activity, and obstetric history. In the mental-emotional area, all studies confirmed the impact of depression and anxiety. Social factors, including smoking, alcohol consumption, the quality of relationship with husband, partner's loyalty, sexual knowledge, access to health care, a history of divorce or the death of a husband, living apart from a spouse, and a negative understanding of women's health were found to affect sexual function; however, there were conflicting results regarding the effects of education, occupation, socioeconomic status, marital duration, and frequency of sexual intercourse. Copyright © 2016. Published by Elsevier B.V.

factors affecting antenatal care service utilization in yem special ...

African Journals Online (AJOL)

jhon

assess antenatal care utilization and factors that affect it in Yem Special Woreda, South Western Ethiopia. METHODS: A ... A pre-tested structured questionnaire consisting of information on socio- ..... model and access to medical care: does it.

Towards predicting basin-wide invertebrate organic biomass and production in marine sediments from a coastal sea.

Directory of Open Access Journals (Sweden)

Brenda J Burd

Full Text Available Detailed knowledge of environmental conditions is required to understand faunal production in coastal seas with topographic and hydrographic complexity. We test the hypothesis that organic biomass and production of subtidal sediment invertebrates throughout the Strait of Georgia, west coast of Canada, can be predicted by depth, substrate type and organic flux modified to reflect lability and age of material. A basin-wide database of biological, geochemical and flux data was analysed using an empirical production/biomass (P/B model to test this hypothesis. This analysis is unique in the spatial extent and detail of P/B and concurrent environmental measurements over a temperate coastal region. Modified organic flux was the most important predictor of organic biomass and production. Depth and substrate type were secondary modifiers. Between 69-74% of variability in biomass and production could be explained by the combined environmental factors. Organisms <1 mm were important contributors to biomass and production primarily in shallow, sandy sediments, where high P/B values were found despite low organic flux. Low biomass, production, and P/B values were found in the deep, northern basin and mainland fjords, which had silty sediments, low organic flux, low biomass of organisms <1 mm, and dominance by large, slow-growing macrofauna. In the highest organic flux and biomass areas near the Fraser River discharge, production did not increase beyond moderate flux levels. Although highly productive, this area had low P/B. Clearly, food input is insufficient to explain the complex patterns in faunal production revealed here. Additional environmental factors (depth, substrate type and unmeasured factors are important modifiers of these patterns. Potential reasons for the above patterns are explored, along with a discussion of unmeasured factors possibly responsible for unexplained (30% variance in biomass and production. We now have the tools for basin

Environmental Factors Affecting Where People Geocache

Directory of Open Access Journals (Sweden)

Jennifer Golbeck

2016-04-01

Full Text Available Outdoor leisure activities are important for public health as well as family cohesiveness, yet environmental factors may easily affect someone’s ability to participate in such activities. We explored this with a focus on the social web-based treasure hunt game called Geocaching. We collected data on all US and Canadian geocaches from OpenCaching.com and conducted an online survey with twenty geocachers as a follow-up to our data analysis. Data analysis showed that geocaches were more often found in areas that were wealthier, better educated, younger, and more urban, and had higher population density and better weather. Survey results showed similar trends: Most people actively thought about where they would cache and tried to minimize risks, despite cache hiders thinking less about these concerns. These results further emphasize the importance of environmental factors when it comes to participation in outdoor activities and leads to Human–Computer Interaction design implications for location-based online social activities.

MODIS Based Estimation of Forest Aboveground Biomass in China.

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Guodong Yin

Full Text Available Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS dataset in a machine learning algorithm (the model tree ensemble, MTE. We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.

MODIS Based Estimation of Forest Aboveground Biomass in China

Science.gov (United States)

Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

2015-01-01

Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha−1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y−1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y−1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y−1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests. PMID:26115195

MODIS Based Estimation of Forest Aboveground Biomass in China.

Science.gov (United States)

Yin, Guodong; Zhang, Yuan; Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

2015-01-01

Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.