246 research outputs found

    Leaving no one behind: Supporting women, poor people, and indigenous people in wheat-maize innovations in Bangladesh

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    This guidance note for scientists and research teams acknowledges the complexity of marginalization processes and provides recommendations for making sure no one is left behind. It draws on GENNOVATE findings from a community in Bangladesh where the indigenous Santals, Bengali Muslims, and Hindus live and work together

    Optimization and enhancement of soil bioremediation by composting using the experimental design technique

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    The objective of this study was the application of the experimental design technique to optimize the conditions for the bioremediation of contaminated soil by means of composting. A low-cost material such as compost from the Organic Fraction of Municipal Solid Waste as amendment and pyrene as model pollutant were used. The effect of three factors was considered: pollutant concentration (0.1-2 g/kg), soil:compost mixing ratio (1:0.5-1:2 w/w) and compost stability measured as respiration index (0.78, 2.69 and 4.52 mg O2 g⁻¹ Organic Matter h⁻¹). Stable compost permitted to achieve an almost complete degradation of pyrene in a short time (10 days). Results indicated that compost stability is a key parameter to optimize PAHs biodegradation. A factor analysis indicated that the optimal conditions for bioremediation after 10, 20 and 30 days of process were (1.4, 0.78, 1:1.4), (1.4, 2.18. 1:1.3) and (1.3, 2.18, 1:1.3) for concentration (g/kg), compost stability (mg O₂ g−1 Organic Matter h−1) and soil:compost mixing ratio, respectively

    Preliminary screening of co-substrates for bioremediation of pyrene-contaminated soil through composting

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    The feasibility of using different organic amendments of different origin and properties in the bioremediation of pyrene-contaminated soil by means of composting has been tested. The selected pyrene concentration was 1 g of pyrene per kg of dry soil. The organic amendments used include: raw organic fraction of municipal solid wastes (OFMSW), industrial compost from OFMSW composting (COFMSW), compost derived from home composting of OFMSW (HCOFMSW), anaerobically digested sludge (ADS), non-digested activated sludge (NDS) and centrifuged non-digested activated sludge (CNDS). The degradation rate was related to the amendment properties that directly affected the composting process. Raw OFMSW was not capable to enhance pyrene degradation in comparison to control, but stable HCOFMSW exhibited the highest removal rate (69%). The amendments stability and the temperatures reached as a consequence influenced the process, and thermophilic temperatures showed an inhibition effect on the microbial activity related to pyrene degradation. Some of the tested wastes need to be further investigated to find inexpensive organic amendments for soil bioremediation

    Circle grid fractal plate as a turbulent generator for premixed flame: an overview

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    This review paper focuses to ascertain a new approach in turbulence generation on the structure of premixed flames and external combustion using a fractal grid pattern. This review paper discusses the relationship between fractal pattern and turbulence flow. Many researchers have explored the fractal pattern as a new concept of turbulence generators, but researchers rarely study fractal turbulence generators on the structure premixed flame. The turbulent flow field characteristics have been studied tand investigated in a premixed combustion application. In terms of turbulence intensity, most researchers used fractal grid that can be tailored so that they can design the characteristic needed in premixed flame. This approach makes it extremely difficult to determine the exact turbulent burning velocity on the velocity fluctuation of the flow. The decision to carry out additional research on the effect circle grid fractal plate as a turbulent generator for premixed flame should depends on the blockage ratio and fractal pattern of the grid. 1

    Developing Scaling Laws to Predict Compressive Mechanical Properties and Determine Geometrical Parameters of Modified BCC Lattice Structures

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    The objective of this study is to develop generalized empirical closed-form equations to predict the compressive mechanical properties and determine geometrical parameters. To achieve that, 117 models are built and analyzed using ABAQUS/CAE 2016 to provide two types of reliable data: one for lattice mechanical properties based on finite element method and the other for geometrical parameters using the measurements of ABAQUS diagnostic tool. All the models are created by modifying the basic feature of body-centered cubic lattice structure based on a range of strut angles, a set of relative densities, and two design sets. Also, the influence of lattice cell tessellations and material distribution at strut intersections are considered within these models to provide accurate results. The first data set is fitted with the scaling laws, relating relative elastic modulus and stress with the relative density, to determine Gibson and Ashby\u27s coefficients. The second type of data regarding lattice geometries is correlated with the relative density to estimate actual lattice volume, strut radius, aspect ratio, and overall lattice volume. By this way, these equations can be used to predict directly the lattice characteristics and geometrical parameters without the need for ABAQUS. The results show that the generalized empirical closed-form equations can predict well both the lattice characteristics and geometries. In addition, the relative stresses and elastic modulus increase with increasing the strut angles since the main deformation mechanisms move toward stretch-dominated rather than bending. Besides, Gibson and Ashby\u27s coefficients along with the geometrical factors of aspect ratios are found to be approximately similar for both generations. This study contributes to developing efficient equations to provide the researchers with a preliminary insight about the best lattice design and its compatibility in a certain application before starting the fabrication process

    Investigating the intracellular bactericidal effects of rifampicin loaded S-protected thiomeric chitosan nanocargoes against Mycobacterium tuberculosis

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    The antibiotic drug resistance in Mycobacterium tuberculosis (M.tb) is typically associated with immune evasion shared by pathogenic bacterium and intrinsic antimycobacterial drug resistance. These factors significantly contribute to the limited delivery of drugs intracelullary thereby posing an ever-growing threat to mankind. A promising approach to tackle this multi-drug resistance is to use nanocargoes (NCs) based drug delivery approach. The aim of the present study was to develop mannose coated S-protected thiomeric site-specific nanocargoes (MPTCh-NCs) of Rifampicin (Rif) in order to deliver drug locally inside the macrophages. This NCs-based delivery system modifies the macrophage activation states via mannose receptors and endocytosis to alter the macrophage activation state thus providing synergistic antimycobacterial effects. MPTCh-NCs were synthesized by ionic gelation method and assessed for particle size and encapsulation efficiency Moreover, MPTCh-NCs were also investigated in in vitro for drug release, macrophage uptake, buffering potential, Mycothione reductase (MTR) inhibition ability, minimum inhibitory concentration (MIC), phagolysosomal fusion, reactive oxygen species (ROS) production apoptosis and RV 1258 inhibition. The in vivo bioavailability study of MPTCh-NCs was also evaluated in male BALB/c models over a period of 72 h. The optimized MPTCh-NC formulation was nanosized (390 ± 20 nm) with better EE of Rif i.e. 73.68 ± 5.99%. The MPTCh-NCs showed better buffering capacity at different pH ranges, 35.69 folds higher macrophage uptake than Rif with P-gp inhibition potential and pronounced MTR inhibition potential. The MPTCh-NCs exhibited MIC of 16 μg/ml by drug susceptibility testing. Flow cytometric analysis of MPTCh-NCs exhibited, increased apoptosis (33.29%). Real time PCR data suggested enhanced RV 1258 inhibition potential (0.387 fold expression) of the MPTCh-NCs. In vivo results indicated increased bioavailability of MPTCh-NCs (AUC 12.31 folds higher) in comparison to conventional drug Rif. In summary, the observed capacity of the mannose coated S-protected NCs-based approach to deliver therapeutic levels of Rif selectively has potential to improve the therapeutic management against drug resistant tuberculosis

    Effects of compost stability and contaminant concentration on the bioremediation of PAHs contaminated soil through composting

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    The objective of this study was to investigate the effect of two factors: the stability degree (0.37-4.55 mg O₂ g⁻¹ Organic Matter h⁻¹) of different composts derived from the organic fraction of municipal solid wastes and the concentration of a complex mixture of PAHs including flourene, phenanthrene, anthracene, flouranthene, pyrene and benzo(a)anthracene in the bioremediation of soil. The two factors were systematically studied applying central composite design methodology. The obtained results demonstrated that compost stability degree was particularly important during the first stage of the process. Stable composts enhanced the levels of degradation in soil-compost mixture and a degradation rate of 92% was achieved in this period, but only 40% was degraded with the least stable compost. The PAHs concentration was also important during the process, since the degradation rates increased with the increase in the PAHs concentration. Moreover, all the individual PAHs demonstrated a notable decrease in their concentrations after the incubation period, but pyrene was degraded to lower levels in some treatments compared to others PAHs

    Anaerobic degradation of PAHs in soil : impacts of concentration and amendment stability on the PAHs degradation and biogas production

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    In this study, the bioremediation of polycyclic aromatic hydrocarbons (PAHs)-contaminated soil under strict anaerobic-methanogenic conditions was systematically studied applying the central composite design approach. The effect of PAHs concentration and the stability of the compost as an organic amendment for anaerobic digestion were examined. In all assays, the used methanogenic consortium was able to degrade the PAHs although some inhibition effects were observed during the initial stage in some cases. The degradation rates varied between 31.4 and 90.6% during 50 days incubation period. The study demonstrated that the PAHs concentration influences the degradation rate where more degradation was observed by increasing the concentration of PAHs. However, the biogas production as a result of the digestion process was more influenced by the compost stability which also has its effect on the degradation rates as more degradation occurred with more stable compost, but more biogas was produced with less stable compost, which indicates that the biogas is mainly produced by the anaerobic digestion of the amended compost. Finally, it seems that compost addition is required to improve the process in some cases but in other circumstances it does not greatly improve the bioremediation of PAHs

    Performance of different systems for the composting of the source-selected organic fraction of municipal solid waste

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    Performance of three pile composting systems at field-scale were studied and compared in the composting of source-selected organic fraction of municipal solid waste (OFMSW): turned pile (TP), static forced-aerated pile (SAP) and turned forced-aerated pile (TAP). Routine parameters such as temperature, oxygen content, moisture and porosity were monitored. Temperature was found to be higher in turned systems whereas oxygen content was higher in forced-aerated systems. Although the initial air-filled porosity (AFP) for all mixtures was high, around 70%, the material tended to compact in the static system. A high degree of heterogeneity was found in the non-turned system. Extent of biodegradation was measured by respiration techniques (from 5.3 to 1.1 mg [O2] g [organic matter {OM}]−1 h−1 in TP and from 4.7 to 0.7 mg [O2] g [OM]−1 h−1 in turned forced-aerated pile). The non-turned compost showed a low level of stability (3.6 mg [O2] g [OM]−1 h−1) and the lowest maturity grade (I) measured by the self-heating test. In forced-aerated systems a low intermittent aeration rate of 1 l kg [volatile solids {VS}]−1 min−1 (5 min on, 30 min off) proved to be excessive, causing major water losses and hampering moisture control. Comparison of the results obtained for TP and TAP demonstrated that the investment cost in a forced-aeration system is not necessary for this waste. Hence, turned systems are recommended for OFMSW pile composting

    Impact of the nematophagous fungus Pochonia chlamydosporia on nematode and microbial populations

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    The microbial and nematode populations associated with two plants (tomato and cabbage) inoculated with the nematophagous fungus, Pochonia chlamydosporia var. chlamydosporia or root knot nematode (Meloidogyne incognita), or both, were compared with those in unplanted controls. The dominant factor affecting culturable microbial populations was found to be the presence or absence of tomato plants. Generally microbial colony counts were lowest in unplanted soil, small increases were associated with cabbage and significantly greater numbers with tomato plants. Differences in microbial diversity (estimated from community profiles of carbon substrate utlisation, using Biolog) were observed between planted and unplanted soils, however, there were few differences between soils with either of the two plants. The presence of P. chlamydosporia was associated with a reduction in the numbers of plant parasitic nematodes (51%-78%) including the migratory ectoparasites, whereas free-living nematodes, culturable bacteria and bacterial populations assessed by Biolog were unaffected by the application of fungus
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