Investigated in this paper is an extended (3+1)-dimensional Kadomtsev-Petviashvili equation. We determine the
N
-soliton solutions of that equation via an existing bilinear form, and then construct ...the
M
th-order breather and
H
th-order lump solutions from the
N
-soliton solutions using the complex conjugated transformations and long-wave limit method, where
N
,
M
, and
H
are the positive integers. In addition, we develop the hybrid solutions composed of the first-order breather and one soliton, the first-order lump and one soliton, as well as the first-order lump and first-order breather. Through those solutions, we demonstrate the (1) one breather or lump, (2) interaction between the two breathers or lumps, (3) interaction between the one breather and one soliton, (4) interaction between the one lump and one soliton, and (5) interaction between the one lump and one breather. We observe that the amplitude, shape, and velocity of the one breather or lump remain unchanged during the propagation. We also find that the amplitudes, shapes, and velocities of the solitons, breathers, and lumps remain unchanged after the interactions, suggesting that those interactions are elastic.
This paper begins with a review on the current techniques used for the treatment and recovery of waste oil, which is then followed by an extensive review of the recent achievements in the sustainable ...development and utilization of pyrolysis techniques in energy recovery from waste oils. The advantages and limitations shown by the use of pyrolysis technique and other current techniques were discussed along with the future research that can be performed on the pyrolysis of waste oil. It was revealed that the current techniques (transesterification, hydrotreating, gasification, solvent extraction, and membrane technology) are yet to be sustainable or completely feasible for waste oil treatment and recovery. It was established that pyrolysis techniques offer a number of advantages over other existing techniques in recovering both the energetic and chemical value of waste oil by generating potentially useful pyrolysis products suitable for future reuse. In particular, microwave pyrolysis shows a distinct advantage in providing a rapid and energy-efficient heating compared to conventional pyrolysis techniques, and thus facilitating increased production rates. It was found that microwave pyrolysis of waste oil showed good performance with respect to product yield, reaction time, energy consumption, and product quality, and thus showing exceptional promise as a sustainable means for energy recovery from waste oils. Nevertheless, it was revealed that some important characteristics of the pyrolysis process have yet to be fully investigated. It was thus concluded that more studies are needed to extend existing understanding in the optimal reaction and process parameters in order to develop the pyrolysis technology to be a sustainable and commercially viable route for energy recovery from problematic waste oils.
In this paper, a (2+1)-dimensional generalized Konopelchenko-Dubrovsky-Kaup-Kupershmidt system in fluid mechanics and plasma physics is investigated. Bilinear form under certain coefficient ...constraints is given via the Hirota method. The
N
th-order Pfaffian solutions are proved by means of the Pfaffian technique, where
N
is a positive integer.
N
-soliton and the higher-order breather solutions are exported through the
N
th-order Pfaffian solutions. Different two-soliton/breather structures and their dynamics are derived. Elastic/inelastic interactions between the two solitons/breathers are investigated. Graphical representations of the influence of the coefficients in the equation on the velocities and amplitudes of the solitons and breathers are exhibited.
•Rapeseed biodiesel shows extended flame reaction zone with no soot formation.•RME spray flame shows higher droplet number density and volume flux than diesel.•RME droplet size and velocity ...distribution are similar to diesel.•Blending 50% RME with diesel reduces soot formation non-linearly.•RME shows lower NOx and higher CO emissions level compared to diesel.
The spray combustion characteristics of rapeseed biodiesel/methyl esters (RME) and 50% RME/diesel blend were investigated and compared with conventional diesel fuel, using a model swirl flame burner. The detailed database with well-characterised boundary conditions can be used as validation targets for flame modelling. An airblast, swirl-atomized liquid fuel spray was surrounded by air preheated to 350°C at atmospheric pressure. The reacting droplet distribution within the flame was determined using phase Doppler particle anemometry. For both diesel and RME, peak droplet concentrations are found on the outside of the flame region, with large droplets migrating to the outside via swirl, and smaller droplets located around the centreline region. However, droplet concentrations and sizes are larger for RME, indicating a longer droplet evaporation timescale. This delayed droplet vaporisation leads to a different reaction zone relative to diesel, with an extended core reaction. In spite of the longer reaction zone, RME flames displayed no sign of visible soot radiation, unlike the case of diesel spray flame. Blending 50% RME with diesel results in significant reduction in soot radiation. Finally, RME emits 22% on average lower NOx emissions compared to diesel under lean burning conditions.
Fluids are studied in such disciplines as atmospheric science, oceanography and astrophysics. In this paper, we investigate a (3+1)-dimensional Korteweg–de Vries equation in a fluid. Bilinear form ...and
N
-soliton solutions are obtained, where
N
is a positive integer. Via the
N
-soliton solutions, we derive the higher-order breather solutions. We observe the interaction between the two perpendicular first-order breathers on the
x
-
y
and
x
-
z
planes and the interaction between the periodic line wave and the first-order breather on the
y
-
z
plane, where
x
,
y
and
z
are the independent variables in the equation. We discuss the effects of
α
,
β
,
γ
and
δ
on the amplitude of the second-order breather, where
α
,
β
,
γ
and
δ
are the constant coefficients in the equation: Amplitude of the second-order breather decreases as
α
increases; amplitude of the second-order breather increases as
β
increases; amplitude of the second-order breather keeps invariant as
γ
or
δ
increases. Via the
N
-soliton solutions, hybrid solutions comprising the breathers and solitons are derived. Based on the Riemann theta function, we obtain the periodic-wave solutions, and find that the periodic-wave solutions approach to the one-soliton solutions under a limiting condition.
Fatigue life prediction of transparent submersible manned cabin (TSMC) structure is investigated. Firstly, a simplified mechanical model of a cylindrical shell-hemispherical shell (CS-HS) structure ...is established, and the strength characteristic of the TSMC structure is gained, as well as deflections and displacements are obtained by solving the model with the non-moment theory and moment theory. Secondly, the load history of the TSMC structure is analyzed, and the load spectrum of this structure is got by analyzing and fitting the existing diving data. Finally, a method of nonlinear virtual interval division technique for the load spectrum is first presented. The predicted results have excellent agreement with the experimental data. The results show that the working depth of the large-deep deep manned cabins is within the range of 0 m–500 m, while the load history is composed of the submersible loading-uploading-unloading and payload-uplifting-unloading. In addition, the load spectrum shows that the number of dives is within the range from 299.7 m to 432.9 m. The proposed model can efficiently provide a guideline of the design and manufacturing of the transparent submersible manned cabin structure.
•A novel parameter criterion for fatigue damage calculation is proposed.•Fatigue life is predicted by the values of reliability and crack length.•Submersible manned cabin structure is investigated.
Next‐generation sequencing technology has afforded the discovery of many novel variants that are of significance to inheritable pharmacogenomics (PGx) traits but a large proportion of them have ...unknown consequences. These include missense variants resulting in single amino acid substitutions in cytochrome P450 (CYP) proteins that can impair enzyme function, leading to altered drug efficacy and toxicity. While most unknown variants are rare, an overlooked minority are variants that are collectively rare but enriched in specific populations. Here, we analyzed sequence variation data in 141,456 individuals from across eight study populations in gnomAD for 38 CYP genes to identify such variants in addition to common variants. By further comparison with data from two PGx‐specific databases (PharmVar and PharmGKB) and ClinVar, we identified 234 missense variants in 35 CYP genes, of which 107 were unknown to these databases. Most unknown variants (n = 83) were population‐specific common variants and several (n = 7) were found in important CYP pharmacogenes (CYP2D6, CYP4F2, and CYP2C19). Overall, 29% (n = 31) of 107 unknown variants were predicted to affect CYP enzyme function although further biochemical characterization is necessary. These variants may elucidate part of the unexplained interpopulation differences observed in drug response.
•Oil palm waste has high carbon content for pyrolysis conversion into biochar.•Microwave pyrolysis produces 38wt% of biochar with high chemical resistance.•Biochar has high surface area, porosity, ...carbon, and low ash and moisture.•Biochar shows potential for use in wastewater treatment, agriculture and energy.
Oil palm waste (OPW), comprising mainly of empty fruit bunch, mesocarp fiber, frond, trunk, and palm kernel shell generated from palm oil industry, was collected, characterized, and then pyrolyzed to evaluate their potential to be converted into biochar with desirable properties for use in multi-applications. The OPW was detected to have considerable amounts of carbon (43–51wt%) and fixed carbon (30–39wt%), showing potential to be converted into carbon-rich biochar. Microwave pyrolysis of palm kernel shell as the selected OPW produced a biochar with zero sulphur content and high heating value (23–26MJ/kg) that is nearly comparable to conventional coal, thus indicating its potential as an eco-friendly solid fuel. The biochar obtained was also showed low moisture (<3wt%) and ash (3wt%), and a highly porous structure with high BET surface area (210m2/g), indicating the presence of many adsorption sites and thus showing desirable characteristics for potential use as pollutant adsorbent in wastewater treatment, or bio-fertilizer to absorb nutrient and promote plant growth. Our results demonstrate that OPW is a biowaste that shows exceptional promise to be transformed into high-grade biochar rather than simply disposed by landfilling or burned as low-grade fuel in boiler.
In this paper, a new class of wideband filtering phase shifters with a pair of controllable out-of-band transmission zeroes is presented for the first time. The proposed wideband filtering ...differential phase shifter consists of two stub-loaded multimode resonators (SLMMR) in the main and reference branches, which can provide a constant phase shift and self-realized generalized Chebyshev filtering function with controllable transmission zeroes by properly setting the impedance ratio <inline-formula> <tex-math notation="LaTeX">R_{\mathrm {z}} </tex-math></inline-formula> of the loaded stub. On the one hand, the prescribed phase shift value, phase deviation, and phase shift bandwidth are deduced that basically dominated by resonant modes of SLMMR together with electrical lengths of the phase-shifting lines. On the other hand, the phase properties of transmission zeroes are systematically investigated to demonstrate that they arouse little effect on the phase shift performance, but highly improve the frequency selectivity in theoretical analysis. Based on the presented synthesis method which simultaneously considers wideband phase shift and bandpass filtering function, the circuit parameters of the entire proposed phase shifter can be synthesized with prescribed phase shift value, phase deviation, bandwidth, return loss, and transmission zero positions. Besides, the phase shift and return loss bandwidth can be determined in the design process. As design examples, two 90° wideband filtering phase shifters with different specifications are synthesized, designed, and fabricated to validate our proposed approach.
In this paper, a new design concept of Schiffman phase shifters under the operation of the second phase period in frequency domain is presented and analyzed. By investigating phase properties of the ...C-section structure, we first find that its second phase period is another independent and distinctive working region for Schiffman phase shifter, in addition to its first phase period. In contrast to traditional counterparts working on the first phase period, which are suitable for small phase shift from 0° to 90°, the Schiffman phase shifters on the second phase period are suitable for the large phase shift from 90° to 180°. It is because of the opposite phase variation property that the electrical length of reference line gets shortened as the phase shift value increases. Compared with the first phase period, the second phase period can achieve wider phase shift bandwidth under the same coupling degree. This feature is believed to be very useful in the limited realizable coupling degree cases. In this context, the closed-form synthesis formulas of Schiffman phase shifter on the second phase period are presented. Meanwhile, detail theoretical analysis of the phase shift bandwidth and phase deviation is carried out. In final, two Schiffman phase shifters on the first and second phase periods are designed and fabricated to validate our proposed concept and approach in the experiment.
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