3,395 research outputs found
Anaerobic Digester Bioaugmentation Influences Quasi Steady State Performance and Microbial Community
Nine anaerobic digesters, each seeded with biomass from a different source, were operated identically and their quasi steady state function was compared. Subsequently, digesters were bioaugmented with a methanogenic culture previously shown to increase specific methanogenic activity. Before bioaugmentation, different seed biomass resulted in different quasi steady state function, with digesters clustering into three groups distinguished by methane (CH4) production. Digesters with similar functional performance contained similar archaeal communities based on clustering of Illumina sequence data of the V4V5 region of the 16S rRNA gene. High CH4 production correlated with neutral pH and high Methanosarcina abundance, whereas low CH4production correlated to low pH as well as high Methanobacterium and DHVEG 6 family abundance. After bioaugmentation, CH4 production from the high CH4 producing digesters transiently increased by 11 ± 3% relative to non-bioaugmented controls (p \u3c 0.05, n = 3), whereas no functional changes were observed for medium and low CH4producing digesters that all had pH higher than 6.7. The CH4 production increase after bioaugmentation was correlated to increased relative abundance of Methanosaeta and Methaospirillum originating from the bioaugment culture. In conclusion, different anaerobic digester seed biomass can result in different quasi steady state CH4production, SCOD removal, pH and effluent VFA concentration in the timeframe studied. The bioaugmentation employed can result in a period of increased methane production. Future research should address extending the period of increased CH4 production by employing pH and VFA control concomitant with bioaugmentation, developing improved bioaugments, or employing a membrane bioreactor to retain the bioaugment
Meta-Analysis of Non-Reactive Phosphorus in Water, Wastewater, and Sludge, and Strategies to Convert it for Enhanced Phosphorus Removal and Recovery
Current and future trends indicate that mining of natural phosphorus (P) reserves is occurring faster than natural geologic replenishment. This mobilization has not only led to P supply concerns, but has also polluted many of the world\u27s freshwater bodies and oceans. Recovery and reuse of this nuisance P offers a long-term solution simultaneously addressing mineral P accessibility and P-based pollution. Available physical, chemical, and biological P removal/recovery processes can achieve low total P (TP) concentrations (≤100 μg/L) and some processes can also recover P for direct reuse as fertilizers (e.g., struvite). However, as shown by our meta-analysis of over 20,000 data points on P quantity and P form, the P in water matrices is not always present in the reactive P (RP) form that is most amenable to recovery for direct reuse. Thus, strategies for removing and recovering other P fractions in water/wastewater are essential to provide environmental protection via P removal and also advance the circular P economy via P recovery. Specifically, conversion of non-reactive P (NRP) to the more readily removable/recoverable RP form may offer a feasible approach; however, extremely limited data on such applications currently exist. This review investigates the role of NRP in various water matrices; identifies NRP conversion mechanisms; and evaluates biological, physical, thermal, and chemical processes with potential to enhance P removal and recovery by converting the NRP to RP. This information provides critical insights into future research needs and technology advancements to enhance P removal and recovery
Halo phenomenon in finite many-fermion systems. Atom-positron complexes and large-scale study of atomic nuclei
The analysis method proposed in Ref. \cite{rotival07a} is applied to
characterize halo properties in finite many-fermion systems. First, the
versatility of the method is highlighted by applying it to light and
medium-mass nuclei as well as to atom-positron and ion-positronium complexes.
Second, the dependence of nuclear halo properties on the characteristics of the
energy density functional used in self-consistent Hartree-Fock-Bogoliubov
calculations is studied. It is found that (a) the low-density behavior of the
pairing functional and the regularization/renormalization scheme must be chosen
coherently and with care to provide meaningful predictions, (b) the impact of
pairing correlations on halo properties is significant and is the result of two
competing effects, (c) the detailed characteristics of the pairing functional
has however only little importance, (d) halo properties depend significantly on
any ingredient of the energy density functional that influences the location of
single-particle levels; i.e. the effective mass, the tensor terms and the
saturation density of nuclear matter. The latter dependencies give insights to
how experimental data on medium-mass drip-line nuclei can be used in the
distant future to constrain some characteristics of the nuclear energy density
functional. Last but not least, large scale predictions of halos among all
spherical even-even nuclei are performed using specific sets of particle-hole
and particle-particle energy functionals. It is shown that halos in the ground
state of medium-mass nuclei will only be found at the very limit of neutron
stability and for a limited number of elements.Comment: 24 Pages, 32 Figures. Accepted for publication in Phys. Rev. C
back-to back with first part (nucl-th/0702050
A study on the effect of silver nitrate and 8-hydroxyquinoline citrate pulsing solutions on Lilium cut flowers
Lilium is one of the most important cut flowers in commercial markets, giving customers ornamental value. Fresh flowers, a highly perishable item, need more care and proper treatment for their longer post-harvest life and due to this, the end users face the post-harvest losses of cut flowers. Such losses can be minimized by using preservative chemical, which plays an important role in increasing the vase life of flowers. To increase the post-harvest life of lilium cut flowers cv. ‘Pavia’, the present investigation was aimed to study the effect of different combinations and concentrations of silver nitrate at 50, 75 and 100 ppm and 8-hydroquinoline citrate at 100, 150 and 200 ppm pulsing solutions with 20 % sucrose. Three replications were completely randomised with 16 treatments and one control. Silver nitrate showed better results in flower bud opening, flower bud opening to complete flowering, flower size, bloom life, dry weight and dry matter percentage. Among the treatment concentrations, AgNO3 at 50 ppm with 20% sucrose showed the most effective result on enhancing the selected parameters and improved flower quality during post-harvest life. Among the treatment combinations, 8-HQC at 100 ppm + AgNO3 at 75 ppm with 20 % sucrose showed better results. These findings will be useful to researchers, farmers, and end users to retain the ornamental value of lilium cut flowers for longer than usual
Response of preservative chemicals on the shelf life of cut lilium (Lilium spp.) flower cv. ‘Pavia’
Lilium cut flowers have commercial importance and extending their vase life is vital. An increase in the vase life quality and quantity can directly increase the viability and price realization of commercially important flowers like lilium. Shelf life of cut lilium flower is influenced by using different preservative chemicals and sucrose added in vase solution. Such an extension of vase life can be achieved via chemical treatment. The trial was carried out to examine the effect of various concentration of two chemicals, AgNO3 (silver nitrate) and 8-HQC (8-Hydroxyquinoline citrate) along with sucrose on the shelf life of lilium cut flower cv. ‘Pavia’ (cross between Asiatic and Longiflorum lilies). In the experiment, sucrose (20%), 8-HQC at 3 concentrations (100, 150, 200 ppm) and AgNO3 at 3 concentrations (50, 75, 100 ppm) and water (distilled) as control were tested alone and with combinations. Cut flowers of lilium were treated at one bud opening stage. The trial was carried out in a completely randomized design (CRD) having 16 treatments and one control in three (3) replications. The fresh weight and relative fresh weight of the cut flower spike, opening of all flowers on a spike, vase solution uptake on a day, total vase solution uptake and vase life of lilium cut flower spike showed the best outcome with AgNO3 (50 ppm) and 20% sucrose treatment combination. Out of the two chemicals, silver nitrate showed better results than 8-HQC as a preservative in enhancing the shelf life of cut Lilium flower cv. ‘Pavia’. Analysis of this new and exciting method will be useful to research institutes, commercial producers, wholesalers, retailers, consumers or anyone to choose right chemical and concentration of holding solution to maximize the post-harvest life of lilium cut flowers
Water Requirements For Waterfowl Areas Near the Great Salt Lake Parts V-VI
This report reviews activities on this project since the Progress Report, Part IV, June 1961.
The summer of 1961 has been one of the driest on record for Ogden Bay and Howard Slough Refuge. The extreme shortage of irrigation water has resulted in very little flow in the Howard Slough which originates from return flow. The available water from the Weber River for the Ogden Bay Refuge was also the lowest on record. The scarcity of water at these two refuges has resulted in increased salinity.
Most of the routine work on the project during the summer was done by Ming Change Tsai, graduate assistant in civil engineering who resided at the Ogden Bay Refuge. Mr. Tsai has been assisted in the care of the salinity lysimiters at Ogden Bay Refuge, and in the salinity surveys at the other refuges by Daya Kaushik, graduate assistant in wildlife resources
Automated Delineation of Supraglacial Debris Cover Using Deep Learning and Multisource Remote Sensing Data
Funding: S.K. acknowledges funding from the DST-India via INSPIRE fellowship scheme (DST/INSPIRE Fellowship/2017/IF170680). S.K. acknowledges funding from Deutscher Akademischer Austauschdienst (DAAD) funding ID 2021/22 (57552338).Peer reviewedPublisher PD
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