Subsequent Absorption Research Articles

Acoustic black hole combined with microperforated plate for a rectangular waveguide

The concept of an acoustic black hole (ABH) for anechoic termination of waveguides has been well-established and extensively studied. The fundamental principle underlying an ABH is the deceleration of acoustic waves, leading to the accumulation and subsequent absorption of acoustic energy within the thermoviscous boundary layer formed along the ribs forming its internal structure. The primary advantage of ABHs, in contrast to classical solutions, lies in their avoidance of porous or fibrous materials, rendering them suitable for deployment in challenging environments. While the majority of published works have focused on ABHs with circular cross-sections, recent advancements have demonstrated the effectiveness of the ABH effect also in waveguides with rectangular cross-sections. However, it has been revealed that these ABHs require very fine internal structure for optimal performance, posing challenges in manufacturing. This study addresses this issue by utilizing a microperforated plate to provide the necessary resistance. To model these ABHs, a simple mathematical model is proposed, enabling the optimization of their parameters. Subsequently, their performance is investigated through numerical experiments. The validity of the results is confirmed by comparing them with a detailed mathematical model, ensuring the accuracy and reliability of the proposed approach.

Stretchable MWCNTs-OH/PDMS composite elastomer with hierarchical porous structure for wideband THz absorption

It is important to develop a wideband THz absorber for the prevention of terahertz electromagnetic pollution and information leakage. Some commonly used methods, such as metamaterials or dynamic modulation technology, have played important roles in the study of wideband THz absorbers. However, most of these absorbers are rigid or non-stretchable, which limits the practical applications in large mechanical deformation and non-plane scenarios. In the paper, we proposed a stretchable MWCNTs-OH/PDMS composite elastomer using the sugar template method. A series of characterization methods were carried out to verify the excellent compatibility of PDMS and MWCNTs-OH. Benefiting from its hierarchical porous structure, the draw-length ratio of sample and tensile strength reaches ∼ 190% and ∼ 0.4 MPa, respectively. More THz waves could be trapped inside the sample for conductive loss because of better impedance matching and conductivity loss (the smallest square value is ∼0.4 kΩ/□), which leads to wideband and high absorptivity (over 98% in 0.2∼2.0 THz range). Furthermore, the tested value of EMI SE was over 10 dB in 0.22∼1.82 THz frequency range at transmission mode. Combined with inherent hydrophobicity characteristics, the material also could be used in humid and rainy environments. The systemic study of stretchable MWCNTs-OH/PDMS composite elastomer will provide theoretical and technical support for subsequent THz absorption in practical scenarios.

Pivotal Role of Mixed‐Layer Depth in Tropical Atlantic Multidecadal Variability

AbstractThe tropical arm of Atlantic Multidecadal Variability (AMV) influences climate worldwide, yet the mechanisms generating it remain unclear. Here, we examine experiments with sea surface temperature (SST)‐restoring in the extratropical North Atlantic in multiple models and use mixed‐layer heat budgets to elucidate the important mechanisms. Our results demonstrate that the tropical AMV is driven by wind‐mixed‐layer‐SST feedback. The evolution has two phases with tropical AMV SST anomalies growing from April to October and decaying from November to March. The amplitude of the growth phase surpasses that of the decay phase, resulting in overall tropical Atlantic warming during positive AMV phases. During summer, positive SST anomalies in the extratropics weaken the trade winds, resulting in a shallower mixed‐layer with reduced heat capacity. Subsequent absorption of climatological shortwave radiation in this shallower mixed‐layer then causes SSTs to warm, generating the tropical AMV. Importantly, anomalous surface heat‐fluxes make modest contributions to tropical AMV in these experiments.

Functionality of wet-granulated disintegrant in comparison to directly incorporated disintegrant in a poorly water-soluble tablet matrix

Tablet disintegration is crucial for drug release and subsequent systemic absorption. Although factors affecting the disintegrant’s functionality have been extensively studied, the impact of wet granulation on the performance of disintegrants in a poorly water-soluble matrix has received much less attention. In this study, the disintegrants, crospovidone (XPVP), croscarmellose sodium (CCS) and sodium starch glycolate (SSG), were wet-granulated with dibasic calcium phosphate dihydrate as the poorly water-soluble matrix and polyvinylpyrrolidone as the binder. The effect of wet granulation was studied by evaluating tablet tensile strength and disintegratability. Comparison between tablets with granulated or ungranulated disintegrants as well those without disintegrants were also made. Different formulations showed different degrees of sensitivity to changes in tablet tensile strength and disintegratability post-wet granulation. Tablet tensile strength decreased for tablets with granulated disintegrant XPVP or CCS, but to a smaller extent for SSG. While tablets with granulated XPVP or CCS had increased disintegration time, the increment was lesser than for SSG, suggesting that wet granulation impacted a swelling disintegrant more. The findings showed that tablets with wet-granulated disintegrant had altered the disintegrant’s functionality. These findings could provide better insights into changes in the disintegrant’s functionality after wet granulation.

Designing Plastrons for Underwater Bubble Capture: From Model Microstructures to Stochastic Nanostructures.

Bubbles and foams are often removed via chemical defoamers and/or mechanical agitation. Designing surfaces that promote chemical-free and energy-passive bubble capture is desirable for numerous industrial processes, including mineral flotation, wastewater treatment, and electrolysis. When immersed, super-liquid-repellent surfaces form plastrons, which are textured solid topographies with interconnected gas domains. Plastrons exhibit the remarkable ability of capturing bubbles through coalescence. However, the two-step mechanics of plastron-induced bubble coalescence, namely, rupture (initiation and location) and subsequent absorption (propagation and drainage) are not well understood. Here, the influence of 1) topographical feature size and 2) gas fraction on bubble capture dynamics is investigated. Smaller feature sizes accelerate rupture while larger gas fractions markedly improve absorption. Rupture is initiated solely on solid domains and is more probable near the edges of solid features. Yet, rupture time becomes longer as solid fraction increases. This counterintuitive behavior represents unexpected complexities. Upon rupture, the bubble's moving liquid-solid contact line influences its absorption rate and equilibrium state. These findings show the importance of rationally minimizing surface feature sizes and contact line interactions for rapid bubble rupture and absorption. This work provides key design principles for plastron-induced bubble coalescence, inspiring future development of industrially-relevant surfaces for underwater bubble capture.

Direct observation of electron transfer in solids through X-ray crystallography

Nanoscale electron transfer (ET) in solids is fundamental to the design of multifunctional nanomaterials, yet its process is not fully understood. Herein, through X-ray crystallography, we directly observe solid-state ET via a crystal-to-crystal process. We first demonstrate the creation of a robust and flexible electron acceptor/acceptor (A/A) double-wall nanotube crystal ([(Zn2+)4(LA)4(LA=O)4]n) with a large window (0.90 nm × 0.92 nm) through the one-dimensional porous crystallization of heteroleptic Zn4 metallocycles ((Zn2+)4(LA)4(LA=O)4) with two different acceptor ligands (2,7-bis((1-ethyl-1H-imidazol-2-yl)ethynyl)acridine (LA) and 2,7-bis((1-ethyl-1H-imidazol-2-yl)ethynyl)acridin-9(10H)-one (LA=O)) in a slow-oxidation-associated crystallization procedure. We then achieve the bottom-up construction of the electron donor incorporated-A/A nanotube crystal ([(D)2⊂(Zn2+)4(LA)4(LA=O)4]n) through the subsequent absorption of electron donor guests (D = tetrathiafulvalene (TTF) and ferrocene (Fc)). Finally, we remove electrons from the electron donor guests inside the nanotube crystal through facile ET in the solid state to accumulate holes inside the nanotube crystal ([(D•+)2⊂(Zn2+)4(LA)4(LA=O)4]n), where the solid-state ET process (D – e– → D•+) is thus observed directly by X-ray crystallography.

Effects of exogenous chloride ions on the migration and transformation of Cd in a soil-rice system

Soil cadmium (Cd) contamination has emerged as a significant global environmental concern, posing numerous risks to individual organisms and entire ecosystems. Concurrently, the global increase in pesticide usage has elevated the influx of chloride ions (Cl−) into the soil. Given Cl−’s robust ability to coordinate and complex with various heavy metal ions, understanding its influence on the migration and transformation of Cd in soil-rice systems is essential for the rational application of pesticides and the effective mitigation of soil heavy metal pollution. In this paper, we explained the effect of Cl− on the environmental behavior of Cd in the soil-rice system in terms of growth traits, Cd uptake and accumulation by rice, and Cd solid-solution phase interface behavior through pot experiments and sand culture experiments. The results showed that Cd concentrations in all parts of the rice treated with CaCl2 during the filling period were lower than those in the Ca(NO3)2-treated group, with Cd accumulation diminishing as Cl− concentration increased. This suggests that the filling period is critical for Cd uptake and accumulation in rice. Unlike the accompanying anion NO3−, exogenous Cl− reduced Cd concentrations in the soil solution but increased them in rice. Notably, when the Cd/Cl ratio ranged from 0.625 to 2.5, Cl− formed predominantly CdCl+-complexes with free Cd2+ in the soil solution, enhancing the mobilization of Cd bound to soil particles and its subsequent absorption by rice. This study aims to assess Cl−’s effect on Cd migration and transformation in soil-rice systems, providing insights for safe rice production on Cd-contaminated soils and rational use of chlorine-containing pesticides.

How Microbubble-Enhanced Shock Waves Promote the Delivery of Lipid-siRNA across Neuronal Plasma Membrane: A Computational Study.

In this computational study, we examine the potential of microbubble-enhanced shock waves to improve the delivery of lipid-siRNA nanoparticles across neuronal plasma membranes with the ultimate aim of enhancing brain tumor treatment. We critically evaluate several variables related to experiments, including the bubble size, the shock speed and action time, and the amount of siRNA encapsulated in the liposome. Our findings reveal that microbubble-enhanced shock waves are essential for the high delivery of small lipid vesicles (under 30 nm diameter); its corresponding variables significantly impact drug penetration and absorption rates and influence the overall efficacy of the drug delivery system. Long-time recovery simulations further provide valuable insights into the self-healing ability of the plasma membrane following shock wave exposure and the subsequent absorption dynamics of siRNA. This work provides the dynamic process of siRNA released from lipid vesicles with shock wave and nanobubbles, thereby serving as a molecular mechanism support for developing tunable delivery systems for RNA-based therapy in brain tumors.

Efficient operation of earth–air heat exchanger system for air cooling in a hot climate based on a new control strategy

The present research contributes to filling a gap not covered in the previous studies on shallow geothermal applications using earth-to-air heat exchanger (EAHE) systems. The authors think that operating the EAHE continuously for long periods, as presented in many of the previous studies, is not efficient, and this is due to the following reasons:- At specific periods, especially during the night and early morning, the difference between the ambient air temperature (Tamb) and the undisturbed ground temperature (UGT) is small and even negative, meaning the ambient air is colder than the ground.- The continuous operation of the EAHE for a long time leads to the ground saturation with heat, which means that the ground cannot absorb more heat from the EAHE inlet air.So, the present study investigates performance improvement by applying a control strategy to the EAHE system according to two different modes: mode 1 and mode 2. These two operational modes depend on the difference between the ambient air temperature and the UGT value. In mode 1, the ambient air flows inside the EAHE and supplies fresh air to the building. This mode is applied when the temperature difference (Tamb-UGT) exceeds 1.5 οC. When the condition of mode 1 is not satisfied, mode 2 is used, where the ambient air bypasses the EAHE and is supplied directly to the ventilated space. To carry out the present investigation, a numerical model of the EAHE system is developed, and its results are validated against published data from the literature.The simulation of EAHE in Madinah City, KSA, presenting a hot climate region, has been carried out. The study's results confirmed that the control strategy is an efficient solution for the continuous operation of the EAHE. The applied control strategy guarantees that the air supplied to the building is the coldest among the ambient air and the EAHE outlet air. Also, it has been shown that when the control is applied (mode 2), the temperature of the air supplied to the building is 1.5 °C lower than that of the case related to mode 1. Finally, the results showed that the ground can be recovered thermally when the air bypasses the EAHE (mode 2). The ground temperature recovers almost to its undisturbed value during specific periods, which enhances the potential for subsequent heat absorption.

Metabolic Water As a Route for Water Acquisition in Vertebrates Inhabiting Dehydrating Environments.

Vertebrates have expanded their habitats during evolution, which accompanies diversified routes for water acquisition. Water is acquired by oral intake and subsequent absorption by the intestine in terrestrial and marine animals which are subjected to constant dehydration, whereas most water is gained osmotically across body surfaces in freshwater animals. In addition, a significant amount of water, called metabolic water, is produced within the body by the oxidation of hydrogen in organic substrates. The importance of metabolic water production as a strategy for water acquisition has been well documented in desert animals, but its role has attracted little attention in marine animals which also live in a dehydrating environment. In this article, the author has attempted to reevaluate the role of metabolic water production in body fluid regulation in animals inhabiting desiccating environments. Because of the exceptional ability of their kidney, marine mammals are thought to typically gain water by drinking environmental seawater and excreting excess NaCl in the urine. On the other hand, it is established that marine teleosts drink seawater to enable intestinal water and ion absorption, and the excess NaCl is excreted by branchial ionocytes. In addition to the oral route, we suggest through experiments using eels that water production by lipid metabolism is an additional route for water acquisition when they encounter seawater. It seems that metabolic water production contributes to counteract dehydration before mechanisms for water regulation are reversed from excretion in freshwater to acquisition in seawater.

Tuning of magnetosplamon coupling between graphene scatterers for the optimal design of adjustable metasurfaces

The resonance characteristics of magnetically-biased graphene micro-scatterers are thoroughly investigated in the present work using both eigenvalue and full-wave solvers. Initially, the graphene surface conductivity is presented in a tensor form due to the application of a magnetostatic bias field, which is perpendicular to the material’s surface. Then, the simple case of a graphene disk scatterer is examined, and a properly modified eigenvalue formulation is utilized to extract the plasmonic fundamental frequencies. The validity of the modal analysis is verified via a full-wave analysis that involves a plane-wave propagation and the extraction of the subsequent absorption cross-section utilizing the Finite-Difference Time-Domain method. Additionally, the dependence of a single disk scatterer resonances with the magnetostatic bias is evaluated, highlighting that as the bias field is increased, every edge mode degenerates into two sub-modes with an augmented difference between the resonant frequencies. Finally, the plasmonic coupling between adjacent scatterers is studied considering a periodic arrangement, similar to a metasurface, indicating the additional coupling modes as well as the adjustability of the properties with multiple degrees of freedom.

Effect of beta glucan coating on controlled release, bioaccessibility, and absorption of β-carotene from loaded liposomes.

Recently, the use of biopolymers as coating material to stabilise phospholipid-based nanocarriers has increased. One such class of biopolymers is the dietary fibre beta-glucan (βG). In this study, we developed and characterized beta-carotene (βC) loaded βG coated nanoliposomes (GNLs) to investigate the effect of βG coating on the stability, controlled release, bioaccessibility, diffusion and subsequent absorption of the lipophilic active agent. The size, charge (Z-potential), and FTIR spectra were measured to determine the physicochemical stability of GNLs. βG coating reduced the bioaccessibility, provided prolonged release and improved the antioxidant activity of the nanoliposomes. Multiple particle tracking (MPT) data suggested that βC-GNLs were less diffusive in porcine intestinal mucus (PIM). Additionally, the microviscosity of the PIM treated with GNLs was observed to be higher (0.04744 ± 0.00865 Pa s) than the PIM incubated with uncoated NLs (0.015 ± 0.0004 Pa s). An Ex vivo experiment was performed on mouse jejunum to measure the absorption of beta-carotene from coated (βC-GNLs) and uncoated nanoliposomes (βC-NLs). Data showed that after 2 hours, 27.7 ± 1.3 ng mL-1 of βC encapsulated in GNLs and 61.54 ± 3 ng mL-1 of the βC encapsulated in uncoated NLs was absorbed by mouse intestinal mucosa. These results highlight that coating with βG stabilise NLs during gastrointestinal digestion and provides more sustained release of βC from nanoliposomes.

Model Informed-Development of Amorphous Systems (MI-DAS) - an in-silico polymer selection tool for ASD development

Forming amorphous solid dispersions (ASDs) is one method for improving the solubility and subsequent absorption of poorly-water soluble drugs. An ASD is a matrix of a poorly water-soluble compound with a hydrophilic polymer carrier, which stabilises the drug in its amorphous form. The choice of polymer is often made based on previous success and precedence in other ASD products, and not on the suitability for the drug in development. A bespoke in-silico polymer selection tool (PST) has been developed which selects polymers based on their structural complementarity with the drug. Here, we demonstrate how use of the PST in early development of the Tacrolimus ASD would have identified a more optimal polymer with better API miscibility.

Increased ENaC-mediated liquid absorption across vitamin-D deficient human airway epithelia.

Vitamin D deficiency is a risk factor for exacerbation of obstructive airway disease, a hallmark of which is mucus dehydration and plugging. Calcitriol (the active form of vitamin D) deficiency in cultured human airway epithelia resulted in increased SCNN1G and ATP1B1 mRNAs encoding subunits of ENaC and the Na-K pump compared with supplemented epithelia. These drive the absorption of airway surface liquid. Consistently, calcitriol-deficient epithelia absorbed liquid faster than supplemented epithelia. Calcitriol deficiency also increased amiloride-sensitive Isc and Gt without altering Na-K pump activity, indicating the changes in amiloride-sensitivity arose from ENaC. ENaC activity can be regulated by trafficking, proteases, and channel abundance. We found the effect was likely not induced by changes to endocytosis of ENaC given that calcitriol did not affect the half-lives of amiloride-sensitive Isc and Gt. Furthermore, trypsin nominally increased Isc produced by epithelia ± calcitriol, suggesting calcitriol did not affect proteolytic activation of ENaC. Consistent with mRNA and functional data, calcitriol deficiency resulted in increased γENaC protein. These data indicate that the vitamin D receptor response controls ENaC function and subsequent liquid absorption, providing insight into the relationship between vitamin D deficiency and respiratory disease.NEW & NOTEWORTHY It is unknown why calcitriol (active vitamin D) deficiency worsens pulmonary disease outcomes. Results from mRNA, immunoblot, Ussing chamber, and absorption experiments indicate that calcitriol deficiency increases ENaC activity in human airway epithelia, decreasing apical hydration. Given that epithelial hydration is required for mucociliary transport and airway innate immune function, the increased ENaC activity observed in calcitriol-deficient epithelia may contribute to respiratory pathology observed in vitamin D deficiency.

Development of famotidine-loaded lecithin-chitosan nanoparticles for prolonged and efficient anti-gastric ulcer activity

Lecithin-chitosan nanoparticles (LCNPs) represent an appealing nanocarrier for the oral delivery of hydrophobic drugs. Negatively charged lecithin and positively charged chitosan were permitted to interact to create LCNPs. Their distinctive features enable drugs to be encapsulated into the lipophilic lecithin core while improving their retention in gastric mucosa by the chitosan coat. Famotidine (FMD), a hydrophobic H2-receptor antagonist drug with a short half-life (2.5–4 h), was loaded into LCNPs to enhance its therapeutic efficacy in gastric ulcers through achieving good mucoadhesion and subsequent absorption. The optimal formula with a lecithin to chitosan ratio of 10:1 was selected and exhibited a particle size of 178.5 ± 9.5 nm, a zeta potential of 43.7 ± 2 mV, and an entrapment efficiency of 75.81 ± 2.5 %. It displayed a prolonged in vitro release profile (75.72 % over 24 h) and considerable mucoadhesive properties. FMD-LCNPs were also characterized by differential scanning calorimetry, Fourier transform-infrared (FTIR) spectroscopy, transmission electron microscopy, and stability studies. The in vivo study was performed on ethanol-induced gastric ulcer in a rat model, and the anti-gastric ulcer effects of FMD-free, FMD-marketed product, and FMD-LCNPs were determined by assessing the ulcer severity, antioxidant biomarkers, eNOS levels in addition to histopathological examination. FMD-LCNPs administration resulted in a percentage of protection from gastric severity of 96.25 % and an exceptional ameliorative effect on oxidative stress biomarkers (GSH; 162.36 % increase and MDA; 71.91 % decrease) as compared to other FMD forms. Additionally, FMD-LCNPs showed the strongest eNOS level improvement (130.34 %), which indicated the best healing impact and was confirmed by restoring the gastric mucosa to normal architecture.

Bacterial butyrate mediates the anti-atherosclerotic effect of silybin

Silybin (SIL) is a versatile bioactive compound used for improving liver damage and lipid disorders and is also thought to be beneficial for atherosclerosis (AS). The goal of this study was to investigate the efficacy of SIL in the treatment of AS in ApoE−/−mice fed a high-fat diet and explore the mechanism underlying treatment outcomes. We found that SIL significantly alleviated AS-related parameters, including the extent of aortic plaque formation, hyperlipidemia, and adhesion molecule secretion in the vascular endothelium. 16 S rRNA gene sequencing analysis, together with the application of antibiotics, showed that intestinal butyrate-producing bacteria mediated the ameliorative effect of SIL on AS. Further analysis revealed that SIL facilitated butyrate production by increasing the level of butyryl-CoA: acetate CoA-transferase (BUT). The increased expression of monocarboxylic acid transporter-1 (MCT1) induced by butyrate and MCT4 induced by SIL in the apical and basolateral membranes of colonocytes, respectively, resulted in enhanced absorption of intestinal butyrate into the circulation, leading to the alleviation of arterial endothelium dysfunction. Moreover, the SIL-mediated increase in intestinal butyrate levels restored gut integrity by upregulating the expression of tight junction proteins and promoting gut immunity, thus inhibiting the AS-induced inflammatory response. This is the first study to show that SIL can alleviate AS by modulating the production of bacterial butyrate and its subsequent absorption.

Pseudovicarious Renal Contrast Excretion in a Postoperative Tracheo-Esophageal Fistula patient: Contrast in Pleural Space can be the cause. A Case Report

BACKGROUND: Iodinated contrast is normally not introduced into the intrapleural space except for detecting diaphragmatic injury in stable patients on Computerized Tomography scans, and these studies are limited. Thus, the literature on pleural absorption of contrast is non-existent. We report a novel case with images of renal excretion of contrast after pleural absorption. CASE PRESENTATION: In this case there was inadvertent leakage of contrast into pleural space with subsequent systemic absorption of contrast with renal excretion in a child with a remote history of tracheo-esophageal fistula repair and recent esophageal resection and anastomosis for esophageal stenosis. The child developed a right pleural effusion after the second surgery, proven to be due to anastomotic site leakage. An esophagogram was performed using iodinated contrast, showing the leak and communication with the pleural space. Four hours later, a confusing abdominal radiograph showed excretion of contrast in the kidneys confusing the radiologist reader. CONCLUSION: This imaging finding was due to the systemic absorption of iodinated contrast that had leaked from the anastomotic site into the pleural cavity.

Development of Sustained Release System Based on High Water-Absorbable Gel Formation Using Croscarmellose Sodium, Alkaline Excipients and HPMC (ACSH SR System); Novel Application of Croscarmellose Sodium as a Gel Former.

Croscarmellose sodium, generally used as a superdisintegrant in pharmaceutical formulations, is hydrolyzed to form the gel structure under basic pH conditions. Utilizing this property of croscarmellose sodium, we developed a novel sustained release (SR) system. Immediate release (IR) and SR tablets containing croscarmellose sodium, alkaline excipients and/or hydroxypropyl methylcellulose (HPMC) were prepared and examined for wet strength and in vitro drug release behavior. In vivo oral drug absorption was evaluated for IR tablets, HPMC tablets and our novel SR tablets in fasted Beagle dogs. To form the gel structure even under the physiological condition, alkaline excipients were added into the formulation containing croscarmellose sodium. Furthermore, HPMC was used to make the gel structure strong enough against mechanical destructive forces. The novel alkalized croscarmellose sodium-HPMC (ACSH) SR tablet, consisting of croscarmellose sodium, alkaline excipients, and HPMC, successfully sustained the release of acetaminophen, ibuprofen, or nicardipine hydrochloride, compared with the IR tablets. The ACSH SR system provided a better release of acetaminophen than the HPMC tablet without croscarmellose sodium in the release study using a small volume of liquid, suggesting that substantial release and subsequent absorption would be expected in the distal intestinal segments after oral dosing. The in vivo oral absorption study revealed that the ACSH SR system successfully suppressed and prolonged the plasma concentrations of acetaminophen. This novel ACSH SR system prepared with croscarmellose sodium, alkaline excipients, and HPMC, would be a promising SR formulation for enabling substantial drug absorption in the distal intestinal segments.

GRAVITATIONAL CAPTURE AS A POSSIBLE SCENARIO ORIGIN OF THE MOON

The article is devoted to the problem of the origin of the Moon. Discussed modern scenarios for the formation of the Earth-Moon system: simultaneous formation of the Earth and the Moon in the circumsolar gas of dust disk; impact partial destruction of the Earth by a massive asteroid; gravitational capture of the Moon by the Earth; destruction of the double moon at the beginning when approaching the Earth with possible subsequent absorption components of smaller mass by the Earth. We offer two-stage scenario of gravitational capture of the Moon by the Earth in the early stages Solar system. In the first stage, using a hybrid numerical model in the formulation of the three-body problem (Sun, Earth and Moon) and N-bodies, the search and selection of temporary orbits of the Moon around the Earth is carried out. Using the backward integration method in the formulation N-body problem, the influence of tidal forces on pumping of orbital moment of the Moon (\(P_{{{\text{orb}}}}^{M}\)) relative to the Earth at its own moment \(P_{s}^{M}\) is estimated. As the simulation shows, actions tidal forces alone are not enough to capture the Moon by the Earth in a short time time scale \( \sim 100\) years (\(\Delta P_{s}^{M} \sim {{10}^{{ - 6}}}P_{{{\text{orb}}}}^{M}\)). At the second stage, the factor is taken into account viscous-dissipative environment leading to additional “slowing down” of the Moon, due, for example, to collisions with asteroids and the transition of tidal energy into heat, which helps the Moon get rid of excess kinetic energy and gain constant orbit around the Earth.

An integrated process of Fe/C micro-electrolysis-anaerobic hydrolyze-microalgae for treatment of high concentration pharmaceutical wastewater

As a high concentration wastewater of high organic matter content, many toxic substances, large amounts of organic solvents and poor biochemistry, pharmaceutical wastewater is challenging to handle with a single water treatment technology. In this study, a combined process of Fe/C micro-electrolysis (Fe/C-ME)-anaerobic hydrolyze-microalgae was developed to treat high-concentration pharmaceutical wastewater (i.e. 100,000 mg/L chemical oxygen demand (COD), 2800 mg/L ammonia nitrogen (NH3-N) and 130 mg/L total phosphorus (TP)). Firstly, in the Fe/C-ME process, under optimal experimental conditions, the removal rates of COD, NH3-N and TP were 55 %, 36 % and 63 %, and it was worth mentioning that the removal of ammonia nitrogen and total phosphorus may be attributed to the complexation and flocculation of hydrated iron ions. Secondly, the outer circulation anaerobic reactor (OCAR) performed biochemical treatment on pretreated pharmaceutical wastewater, 85 % of COD was removed, and it was found that through anaerobic digestion, and further hydrolyzed and acidified macromolecular pollutants into small molecules to reduce the impact load, which was conducive to the subsequent digestion and absorption of microalgae and improved the treatment efficiency of the aerobic section. The microalgae cultivated by heterotrophy using anaerobic effluent, directly used NH3-N and TP in wastewater to synthesize substances needed for self-growth and reproduction, and removed 88 %, 91 % and 83 % of COD, NH3-N and TP, respectively. The final results indicated that the removal rates of COD, NH3-N and TP in the integrated process of Fe/C-ME-anaerobic hydrolysis-microalgae were 99.8 %, 98.6 % and 98.5 %, respectively, demonstrating that the coupling process is an effective method for treating high-concentration pharmaceutical wastewater.