Mismatched filter for transmit waveform with frequency notches

In order to reduce radar interference on communication systems within shared bands, the radar transmit waveform forms frequency notches in the shared bands. However, because of the notches, the auto-correlation of the transmit waveform with frequency notches leads to high-range sidelobes. In order to achieve low-range sidelobes, the authors propose a mismatched filter. The mismatched filter for the transmit waveform with frequency notches has the same range sidelobes as the auto-correlation of the transmit waveform without frequency notches at the expense of a signal-to-noise ratio (SNR) loss. Simulation and analysis results demonstrate that the proposed mismatched filter always has low sidelobes at the cost of a SNR loss. In addition, simulation results show that the SNR loss is acceptable even for the deep notches (i.e. 20 dB), when the ratio of the waveform energy in the shared bands to the total waveform energy is moderate (i.e. <;8%). However, the SNR loss increases rapidly with the depth of notches, when the ratio is large.Published versio

reductiveleachingoflowgrademanganeseorewithpreprocessedcornstalk

Cornstalk is usually directly used as a reductant in reductive leaching manganese. However, low utilization of cornstalk makes low manganese dissolution ratio. In the research, pretreatment for cornstalk was proposed to improve manganese dissolution ratio. Cornstalk was preprocessed by a heated sulfuric acid solution (1.2 M of sulfuric acid concentration) for 10 min at 80℃. Thereafter, both the pretreated solution and the residue were used as a reductant for manganese leaching. This method not only exhibited superior activity for hydrolyzing cornstalk but also enhanced manganese dissolution. These effects were attributed to an increase in the amount of reductive sugars resulting from lignin hydrolysis. Through acid pretreatment for cornstalk, the manganese dissolution ratio was improved from 50.14% to 83.46%. The present work demonstrates for the first time the effective acid pretreatment of cornstalk to provide a cost-effective reductant for manganese leaching

Eigensubspace method for space–time adaptive processing in the presence of non-i.i.d. clutter and array errors

This study examines space-time adaptive processing in the presence of non-independent and identically distributed (i.i.d.) clutter and array errors. The authors propose a clutter rank estimation method by exploring the spatial-temporal steering vectors of clutter. The proposed method is independent of clutter statistics and direction-independent array errors. They prove that when the proposed clutter rank estimation is used, the estimate of the clutter subspace is asymptotically independent of clutter statistics. This enables an eigensubspace method to acquire the asymptotic independence on clutter statistics. In addition, they prove that the eigensubspace method can suppress the clutter regardless of direction-independent array errors. They also suggest a geometrical non-homogeneity detector for the eigensubspace method. Simulation and experimental results with multi-channel airborne radar measurement (MCARM) data confirm that the eigensubspace method can suppress non-i.i.d. clutter such as discrete clutter as well as correlated clutter regardless of array gain-phase errors. The ability to suppress clutter regardless of clutter statistics and direction-independent array errors makes the eigensubspace method unique and feasible to the practical scenario when clutter is non-i.i.d. and the direction-independent array errors are present.Published versio

Recovery of nickel and molybdate from ammoniacal leach liquor of spent hydrodesulfurization catalyst using LIX84 extraction

Ammonia leaching can achieve selective recovery of nickel and molybdenum without aluminum extraction from spent hydrodesulfurization catalyst. In this study, a method for selective nickel extraction by LIX84 from ammoniacal leach liquor is proposed. After a two-stage countercurrent extraction, 99.977% Ni was extracted, while 0.096% Mo, 0.431% Al and 2.812% P were co-extracted under LIX84 concentration of 5%, initial pH value of 11.5, and phase ratio (O/A) of 2/1.1. Then a 0.1 mol/L oxalic acid (initial pH 1.36) was used to strip Ni-loaded organic phase under the phase ratio (O/A) of 0.5. 99.91% nickel in organic phase can be stripped into aqueous phase, while 91.16% nickel in aqueous phase can be precipitated as pure nickel oxalate dihydrate, and the oxalic acid solution containing dissolved nickel can be returned to the next stripping process to achieve nickel recovery. Subsequently, ammonium molybdate product can be obtained from molybdenum-containing raffinate by evaporation and crystallization after impurity removal. In addition, thermodynamic calculations show that the nickel extraction process by LIX84 from ammoniacal solution is an endothermic reaction. The present approach may efficiently be applied to recovery of molybdenum and nickel from spent hydrodesulfurization catalyst as per the proposed schematic flow-sheet

Facile Synthesis of Highly Emissive All-Inorganic Manganese Bromide Compounds with Perovskite-Related Structures for White LEDs

Lead-free all-inorganic halide materials with different Mn2+-based crystal structures (Cs3MnBr5 and CsMnBr3) were obtained using a convenient synthetic method. Cs3MnBr5 had a bright green emission (522 nm), with a unique single-exponential lifetime (&tau;avg = 236 &micro;s) and a high photoluminescence quantum yield (82 &plusmn; 5%). A red emission was observed in the case of the CsMnBr3 structure with a two-exponential fluorescence decay curve, and the lifetime was 1.418 &micro;s (93%) and 18.328 &micro;s (7%), respectively. By a judicious tuning of the synthetic conditions, a mixed phase of Cs3MnBr5/CsMnBr3 was also produced that emitted white light, covering almost the entire visible spectrum. White-light-emitting diodes (WLEDs) with color coordinates (0.4269, 0.4955), a color temperature of (3773 K), and a color rendering index (68) were then fabricated using the as-prepared powder of mixed phases of Cs3MnBr5/CsMnBr3 with a commercial UV LED chip (365 nm)

Synthesis of Oxidant Prone Nanosilver To Develop H₂O₂ Responsive Drug Delivery System

Our immune system uses toxicity of hydrogen peroxide to kill off bacterial invaders. In this contribution, we intended to integrate ROS producing capability of immune system with oxidant-sensitive nature of antibacterial silver nanoparticles (Ag NPs) to develop an oxidant drug delivery system. Prior to execute this strategy, we have developed an efficient one-pot synthetic protocol to produce ultrasmall (5 nm), water-stable, and oxidant-prone Ag NPs. Notably, the yield of as-synthesized Ag NPs is 10-fold higher than standard citrate reduction route. The resulting therapeutically active and well-dispersed Ag NPs are used as nanolids to cap the drug loaded nanochannels of porous silica. Upon exposing to H₂O₂, dissolution-accompanied aggregation of Ag nanolids unleashes the encapsulated therapeutic entities from channels of nanocarrier. Combination of antibacterial and anti-inflammatory drugs in single nanocarriers can potentially augment the effectiveness of various therapies