Application of symmetric orthogonal multiwavelets and prefilter technique for image compression

Multiwavelets are new addition to the body of wavelet theory. There are many types of symmetric multiwavelets such as Geronimo-Hardin-Massopust (GHM) and Chui-Lian (CL) multiwavelets. However, the matrix filter generating the GHM system multiwavelets does not satisfy the symmetric property. For this reason, this paper presents a new method to construct the symmetric orthogonal matrix filter, which leads to the symmetric orthogonal multiwavelets (SOM). Moreover, we analyze the prefilter technique, corresponding to the symmetric orthogonal matrix filter, to get a good combining frequency response. To prove the good property of SOM in image compression application, we compared the compression effect with other writers' work, which was in published literature.Facultad de Informátic

Compendium of 5810 genomes of sheep and goat gut microbiomes provides new insights into the glycan and mucin utilization

Background: Ruminant gut microbiota are critical in ecological adaptation, evolution, and nutrition utilization because it regulates energy metabolism, promotes nutrient absorption, and improves immune function. To study the functional roles of key gut microbiota in sheep and goats, it is essential to construct reference microbial gene catalogs and high-quality microbial genomes database. Results A total of 320 fecal samples were collected from 21 different sheep and goat breeds, originating from 32 distinct farms. Metagenomic deep sequencing and binning assembly were utilized to construct a comprehensive microbial genome information database for the gut microbiota. We successfully generated the largest reference gene catalogs for gut microbiota in sheep and goats, containing over 162 million and 82 million nonredundant predicted genes, respectively, with 49 million shared nonredundant predicted genes and 1138 shared species. We found that the rearing environment has a greater impact on microbial composition and function than the host’s species effect. Through subsequent assembly, we obtained 5810 medium- and high-quality metagenome-assembled genomes (MAGs), out of which 2661 were yet unidentified species. Among these MAGs, we identified 91 bacterial taxa that specifically colonize the sheep gut, which encode polysaccharide utilization loci for glycan and mucin degradation. Conclusions By shedding light on the co-symbiotic microbial communities in the gut of small ruminants, our study significantly enhances the understanding of their nutrient degradation and disease susceptibility. Our findings emphasize the vast potential of untapped resources in functional bacterial species within ruminants, further expanding our knowledge of how the ruminant gut microbiota recognizes and processes glycan and mucins

Relationship between water injection volume and liquid injection pressure under the condition of pipeline deformation

Water injection in a closed pipe at one end causes force deformation of the pipe. The expansion changes of the pipeline under different liquid injection pressures are studied combined with theoretical and experimental results. A new relationship between liquid injection pressure and water injection volume of the pipeline is proposed based on elastic mechanics, which is analyzed and verified. The experimental results show that at the early stage, the variation of water injection amount and pipeline deformation show nonlinear change, and the change rate liquid injection volume is constantly decreasing after the liquid injection pressure is increased to some value. Subsequently, there is a linear relationship between water injection and water injection pressure. The inner diameter and length of pipeline have significance influences on the deformation of the pipeline. With the increase of inner diameter and length of the pipeline, the rising rate of water injection volume is accelerated. The proposed equation can well express the relationship between the water injection change volume and the pipeline deformation under water injection pressures. The theory could provide useful theoretical reference for the study of pipeline blockage in the future

Effect of Contact Area on Deflection Flow Behavior in a Bifurcated Fracture

The factors affecting the deflection flow in a bifurcated fracture under the effect of the fracture contact area are discussed. The effects of the contact area and cross-section on the deflection flow are determined using a combination of experiments and numerical simulations. The contact and seepage changes in bifurcated fractures under a confining pressure are monitored using a pressure film. A parallel plate bifurcated fracture model with a single contact area is established, which is in good agreement with the results of the laboratory experiments. Based on numerical simulation experiments, under the effects of the contact area and cross-section, the change in the effective flow path is the main reason for the change in the deflection flow behavior. The proportion of the flow path of the entire fracture is used to reflect the deflection flow characteristics under different contact areas and cross-sectional areas. For a given contact area, the larger the cross-section of the contact area, the larger the difference in the outlet flow of the bifurcated fracture and the more obvious the deflection flow behavior. As the contact area increases and the cross-section is constant, the effective path of the fluid does not change, and the deflection flow behavior does not change. This explanation of the cause of fracture deflection flow is of great significance for studying fracture seepage

Non-Fickian Solute Transport in a Single Fracture of Marble Parallel Plate

Accurate prediction of solute transport processes in a fracture aquifer is an important task not only for proper management of the groundwater but also for pollution control. A key issue of this task is how to accurately obtain the experimental data and to analyze the solute transport in fracture in subsurface hydrology, which would greatly help us to understand the releasing mechanism and transport of the solute in a fracture. In this study, a fracture experiment is conducted in a laboratory based on previous studies. The fracture used with a length of 60 cm and a width of 10 cm is sealed with glass glue to avoid leakage of tracer due to uneven fracture walls. The sodium chloride (NaCl) solute is injected from the left of the fracture. And an electrical conductivity monitoring system is installed on the right of the fracture. Then breakthrough curves (BTCs) of solute transport are fitted using the classical advection-dispersion equation (ADE) and the truncation power-law function (TPL) model in the package of the continuous time random walk (CTRW). The results show that the flow satisfies non-Darcian law in the experimental conditions, which can be better fitted using the Forchheimer equation and Izbash equation. The solute transport presents non-Fickian phenomena and shows a long tailing. The fitting results of the TPL model are far better than ADE in fitting the long tailing at three different flow velocities. Furthermore, electrical conductivity monitoring method not only is effective but also has an advantage of no disturbance to water and concentration fields in a fracture

Groundwater Hydrogeochemical Processes and Potential Threats to Human Health in Fengfeng Coal Mining Area, China

The Fengfeng mining area is in the transition zone between the North China Plain and the Taihang Mountains, and groundwater is the main source of water supply in the district. Under the combined influence of human activities and natural geological conditions, the quality of different types of groundwater varies greatly, posing a potential threat to the safety of drinking water. In this study, hydrogeochemical processes in different types of groundwater were analyzed using multivariate statistical analysis methods with ion–ratio relationships, and a groundwater quality and health risk assessment model was developed. The research findings show that the main chemical components and TDS in the groundwater have obvious spatial distribution characteristics, i.e., the content of deep karst water (DKW) in the west is significantly lower than that of shallow pore water (SPW) in the east, and the hydrochemical type has changed from HCO3–Ca to SO4–Ca. The chemical components of SPW and DKW are mainly derived from silicates and carbonates, accompanied by weathering dissolution of sulphidic minerals, especially SPW. The chemical components of the groundwater was also influenced by the cation exchange reaction and human activities. The quality of the SPW was significantly worse than that of the DKW, and the nitrates in SPW carry a high non-carcinogenic risk, especially to children. The shallow pore water is not suitable for drinking water. This study can provide guidance on the safety of drinking water in the Fengfeng coal mining area and other areas with intensive industrial, mining, and agricultural activities

GEOGRAPHIC INFORMATION SYSTEM BASED APPROACH FOR THE INVESTIGATION OF GROUNDWATER NITROGEN POLLUTION NEAR A CLOSED OLD LANDFILL SITE IN BEIJING, CHINA

Groundwater pollution investigation near old and closed landfill sites is increasingly attracting more attention. Nitrogen compounds, especially those leached from the landfill area, are often regarded as a main pollution source for the groundwater. This study investigated the nitrogen pollution in the groundwater near a closed old landfill area of Beijing, China. The field investigation showed that the nitrate-polluted groundwater was determined as Class VI (refers to bad quality) at the detection rate of over 70% in three out of seven wells. The detection rates of nitrate-polluted groundwater of Class V (refers to bad quality) were more than 50% in four out of seven wells. Geographic information system (GIS) was employed to evaluate the groundwater contamination and investigate the spatial-temporal distributions of the nitrogen pollutants in the shallow groundwater. Elevated concentration of ammonium was observed during May and September when the weather was fairly warm and precipitation was plenty. Extreme concentrations of ammonium were only observed in the area near the well W26, which is adjacent to an old landfill. Nitrate pollution was determined to be severe in the study area based on the detected nitrate concentrations. During winter (November 2007 to January 2008), the nitrate contamination became more severe

A new approach for describing the solute exchange between macropores/fractures and matrix in dual-permeability system

<p>出口 1 至 5 的浓度值和出口处的总浓度记录在"实验数据"中。图 8 至 10 中的仿真结果数据记录在"仿真结果"中。构建数值模型的方法记录在"数值模拟"中,需要 COMSOL Multiphysics 将其打开。</p&gt