Nanoparticle (NP) catalysts are widely used for removal of dyes for single use, but there is an acute need for developing catalysts with high efficiency and reusability for mixed dyes. Here we first optimized the process (reactant proportion, temperature, time, and pH) for biosynthesis of monometallic Ag, Au and bimetallic Au-Ag alloy NP catalysts using Polyalthia longifolia leaf extract. The biosynthesized NP catalysts were characterized by UV-vis, DLS, Zeta potential, TEM and EDX study while the probable biomolecules responsible for biosynthesis were identified by FTIR and GC-MS/MS analysis. The NPs are found to be mostly spherical in shape (size 5-20 nm) with prolonged stability. We evaluated their chemo-catalytic performance through degradation of dyes (methyl orange, methyl violet, methylene blue) in individual and ternary mixture in presence of NaBH 4. The degradation percentage (80.06-96.59% within 5 min), degradation kinetics (k = 0.361-1.518 min-1), half-life (T 50 = 0.457-1.920 min) and 80% degradation (T 80 = 1.060-4.458 min) of dyes indicated highest catalytic activity of alloy in ternary mixture. Here we report a unique vacuum filtration system using alloy coated beads with excellent catalytic activity which could be reused thrice for removal of hazardous ternary mixed dyes with great promise for environmental remediation.
The environmental, economic, and operational limits associated with the physical, chemical, and microbiological techniques for the production of nanoparticles (NPs) are the principal obstructions to their rapid commercial applications in various fields including food packaging and sensing to ensure food quality and safety. Over the years, many reports revealed that the nanotechnological (metal-based NPs) application facilitates an alternate, interactive, reliable, as well as simple technology in the food industries and packaging sector. In this review, we summarized the usage of plant extract for the biosynthesis of bimetallic (Au–Ag) and monometallic counterpart NPs. Further, the impact of reaction conditions and identification of reactive phytochemicals with the reaction mechanism of these nanoparticles was reviewed. The recent progress on the applications of Ag, Au, or Au–Ag NPs in food quality analysis and food packaging was comprehensively discussed. The safety aspect of the nanoparticles for food sector use was also briefly stated.
Data center energy costs are growing concern. Many datacenters use direct-attached-storage architecture where data is distributed across disks attached to several servers. In this organization even if a server is not utilized it can not be turned off since each server carries a fraction of the permanent state needed to complete a request. Operating servers at low utilization is very inefficient due to the lack of energy proportionality. In this research we propose to use outof-band management processor, typically used for remotely managing a server, to satisfy I/O requests from a remote server. By handling requests with limited processing needs, the management processor takes the load off the primary server thereby allowing the primary server to sleep when not actively being used; we call this approach KnightShift. We describe how existing management processors can be modified to handle KnightShift responsibility. We use several production datacenter traces to evaluate the energy impact of KnightShift and show that energy consumption can be reduced by 2.6X by allowing management processors to handle only those requests that demand less than 5
Fipronil -a broad spectrum phenylpyrazole insecticide has high level of toxicity towards environment. Therefore, an easy and reliable analytical method was developed for residue estimation of fipronil to ensure food and environmental safety. A modified QuEChERS technique was followed for estimation of fipronil (5% SC) in paddy ecosystem using GC-ECD and confirmation by GC-MS/MS. The initial residues (0.168–0.794 μg g
−1
) of total fipronil
i.e.,
sum of fipronil and its metabolites (
viz.,
desulfinyl and sulfone) in leaf and soil were dissipated following first order kinetics. About 92–96% of fipronil residues were degraded after 15 days with half-life of 3.4–4.1 days and pre-harvest interval of 19.4–25.7 days in plant. Residues were below level of quantification (<0.005 μg g
−1
) in plant and soil at harvest. The fipronil residues in rice grain present low dietary risk (RQ
d
< 1) to human health. However, high risk (RQ
d
> 1) was predicted for cattle health due to fipronil residues in paddy leaf up to 10 days. The residual level in soil was also at highrisk (RQ
s
> 1) for soil ecological health.
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