Compression Index Research Articles

Compressibility characteristics of municipal solid waste considering multiple factors.

Borehole samples were collected from a municipal solid waste (MSW) landfill in Xi'an, China, and subjected to a series of basic geotechnical and compression tests. This study aims to investigate the influence of composition, dry unit weight, moisture content, organic content, and landfill age on the compressibility of MSW. The results show that with increasing landfill age, the compressible components and organic content exhibit a decreasing trend while the dry unit weight increases. The moisture content does not vary significantly. There is also a linear trend between the logarithm of the primary compression strain and vertical stress. In addition, with an increase in compressible components content, moisture content, and organic content, the modified primary compression index (Cc') shows an increasing trend, whereas with an increase in dry unit weight and landfill age, Cc' shows a decreasing trend. Furthermore, regarding the 34 sets of data, authors only selected five data points for a detailed comparative analysis, this decision was made on the basis that these data points are representative. A modified primary compression index prediction model that considers the dry unit weight, moisture content, and landfill age of the MSW as influencing factors results in a fitting coefficient of 0.797. The Cc' values in this study are within the range of 0.12 to 0.36. These findings provide a reference for the vertical expansion design of existing landfills.

Sigmoni: classification of nanopore signal with a compressed pangenome index.

Improvements in nanopore sequencing necessitate efficient classification methods, including pre-filtering and adaptive sampling algorithms that enrich for reads of interest. Signal-based approaches circumvent the computational bottleneck of basecalling. But past methods for signal-based classification do not scale efficiently to large, repetitive references like pangenomes, limiting their utility to partial references or individual genomes. We introduce Sigmoni: a rapid, multiclass classification method based on the r-index that scales to references of hundreds of Gbps. Sigmoni quantizes nanopore signal into a discrete alphabet of picoamp ranges. It performs rapid, approximate matching using matching statistics, classifying reads based on distributions of picoamp matching statistics and co-linearity statistics, all in linear query time without the need for seed-chain-extend. Sigmoni is 10-100× faster than previous methods for adaptive sampling in host depletion experiments with improved accuracy, and can query reads against large microbial or human pangenomes. Sigmoni is the first signal-based tool to scale to a complete human genome and pangenome while remaining fast enough for adaptive sampling applications. Sigmoni is implemented in Python, and is available open-source at https://github.com/vshiv18/sigmoni.

Estimation of Consolidation and Settlement Characteristics of Madhupur Clay Formation from Dhaka City and Adjacent Area (Savar), Bangladesh

Pleistocene Madhupur Clay covers mostly the investigated region including Dhaka and the surrounding area (Savar). Without knowing the consolidation characteristics and settlement of this Clay, it is difficult for any construction sites to build infrastructure. In Bangladesh, the research on this parameter is limited hence for better understanding the consolidation and settlement behavior of Madhupur Clay samples in this area, a detail investigation is carried out by conducting one dimensional consolidation test. The undisturbed samples, Pleistocene Madhupur Clay and the fill materials which are also partly composed of the Madhupur Clay, are collected from 2.4 m to 4.11 m depths of many distinct points. The compression index Cc and coefficient of compressibility, av of the samples are range from 0.073 to 0.23 and from 0.059 to 0.14m2/mn respectively. The values recommend that both types of specimens are medium plastic clay. The Madhupur Clay are stiff consolidated clay and slightly compressible in nature whereas the Madhupur Clay fill samples are less stiff over consolidated and moderately compressible in nature. Fill samples are settled more with time and are not suitable for Shallow foundation of light or heavy infrastructure. However, the Madhupur Clay samples are only appropriate for light infrastructure foundation. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 12(2), 2023, P 27-39

Target reliability-based design optimization studies on cohesive soil amended with chitosan and casein for liner applications

The current study investigated the primary and secondary compressibility characteristics of organic clay with two biopolymers, Chitosan (Dch) and Casein (Dca) at dosages of 0.5%, 1%, 2%, and 4%. The primary compression index (Cc) values were reduced by 18% and 59% at dosage (Dch and Dca) of 4% at a consolidation pressure of 800 kPa. The secondary compression indices of chitosan and casein-treated soils fell below the normal range specified for organic soils and lay in the range of 0.01–0.017. The biopolymers also accelerated the consolidation process at all dosages (Dch) and 2% Dca. The hydraulic conductivity increased for all dosages of chitosan whereas it declined for all dosages of casein compared to untreated soil. The reliability analysis was conducted for biopolymer-treated soils and presented a rational approach toward the selection of a suitable liner. Chitosan failed to achieve a target reliability index of 3 whereas casein-amended samples attained values equal to and greater than 3 at all dosages and consolidation pressures at COV of Kmax = 20%. At all dosages, the casein-treated soils exhibited reliability index values greater than 3 up to COV of Kmax = 40% indicating the higher stability of casein mixes as a liner material.

Comparison of two self-nanoemulsifying drug delivery systems using different solidification techniques for enhanced solubility and oral bioavailability of poorly water-soluble celecoxib

In this study, we aimed to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) and a solid self-nanoemulsifying granule system (S-SNEGS) to enhance the solubility and oral bioavailability of celecoxib. This process involved the preparation of a liquid SNEDDS (L-SNEDDS) and its subsequent solidification into a S-SNEDDS and a S-SNEGS. The L-SNEDDS consisted of celecoxib (drug), Captex® 355 (Captex; oil), Tween® 80 (Tween 80; surfactant) and D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS; cosurfactant) in a weight ratio of 3.5:25:60:15 to produce the smallest nanoemulsion droplet size. The S-SNEDDS and S-SNEGS were prepared with L-SNEDDS/Ca-silicate/Avicel PH 101 in a weight ratio of 103.5:50:0 using a spray dryer and 103.5:50:100 using a fluid bed granulator, respectively. We compared the two novel developed systems and celecoxib powder based on their solubility, dissolution rate, physicochemical properties, flow properties and oral bioavailability in rats. S-SNEGS showed a significant improvement in solubility and dissolution rate compared to S-SNEDDS and celecoxib powder. Both systems had been converted from crystalline drug to amorphous form. Furthermore, S-SNEGS exhibited a significantly reduced angle of repose, compressibility index and Hausner ratio than S-SNEDDS, suggesting that S-SNEGS was significantly superior in flow properties. Compared to S-SNEDDS and celecoxib powder, S-SNEGS increased the oral bioavailability (AUC value) in rats by 1.3 and 4.5-fold, respectively. Therefore, S-SNEGS wolud be recommended as a solid self-nanoemulsifying system suitable for poorly water-soluble celecoxib.

Physicochemical properties of tablet dosage form based on pre-gelatinized- and phosphorylated-modified starches from white-water yam (Dioscorea alata L.)

Abstract Background White-water yam (Dioscorea alata L.) is one of the potential sources of starch; however, it is not yet available for commercial purposes. Besides, native white-water yam starch (WS) presents limited functionality due to poor flowability, mechanical properties and instability at high temperature and acidic conditions. Therefore, this study aims to modify the starch to improve its characteristics and make it useful as an excipient for the preparation of the tablets. Materials and methods The modification of WS was achieved by physical and chemical treatments, specifically pre-gelatinization and phosphorylation, respectively. Pre-gelatinization WS involves heating, meanwhile phosphorylation WS is obtained by treating WS with sodium tripolyphosphate. Results The results showed that the powder of the modified WS has good characteristics which improved the flowability of the powder mixture as a granule based on density, porosity, compressibility index and swelling power determination. The WS granules were found to display the oval or irregular (polygonal) shape with the amylose content 11.92±0.61% for unmodified WS, 10.41±0.90% for pre-gelatinized WS and 12.61±1.75% for phosphorylated WS. Furthermore, the granule was formulated as an excipient in tablet preparations, and the formulas were compressed after wet granulation. The mechanical properties of the tablets were assessed using uniformity of mass and size, hardness, friability and disintegration time. WS modification affects the hardness of tablets when used as a binder. Phosphorylated WS is recommended to be used as a binder in wet granulation formulations because it produces tablets with a longer disintegration time, which means better binding ability. However, the utilization of modified WS with both pre-gelatinization and phosphorylation leads to tablets with low brittleness compared to others with unmodified binder with the disintegration time still met the requirement of fast disintegrating tablet (<15 minutes). Conclusion All the physical properties studied indicated that the modified WS is a promising pharmaceutical excipient in tablets.

B-move: faster bidirectional character extensions in a run-length compressed index.

Due to the increasing availability of high-quality genome sequences, pan-genomes are gradually replacing single consensus reference genomes in many bioinformatics pipelines to better capture genetic diversity. Traditional bioinformatics tools using the FM-index face memory limitations with such large genome collections. Recent advancements in run-length compressed indices like Gagie et al.'s r-index and Nishimoto and Tabei's move structure, alleviate memory constraints but focus primarily on backward search for MEM-finding. Arakawa et al.'s br-index initiates complete approximate pattern matching using bidirectional search in run-length compressed space, but with significant computational overhead due to complex memory access patterns. We introduce b-move, a novel bidirectional extension of the move structure, enabling fast, cache-efficient bidirectional character extensions in run-length compressed space. It achieves bidirectional character extensions up to 8 times faster than the br-index, closing the performance gap with FM-index-based alternatives, while maintaining the br-index's favorable memory characteristics. For example, all available complete E. coli genomes on NCBI's RefSeq collection can be compiled into a b-move index that fits into the RAM of a typical laptop. Thus, b-move proves practical and scalable for pan-genome indexing and querying. We provide a C++ implementation of b-move, supporting efficient lossless approximate pattern matching including locate functionality, available at https://github.com/biointec/b-move under the AGPL-3.0 license.

Deformation of peat soil reinforcement settlement using single-layer bamboo dendrocalamus asper

Abstract As a unique soil, peat soil has extreme characteristics such as very high compressibility when any load applies to it. It has the condition of partially decomposed plant and animal make it unsuitable used as a foundation for construction. Due to this, the reinforcement of peat must be improved or stable. The stability of peat was more stable when the reinforcement is held or tied with a strong material that can be used for the long term. Therefore, this study to identify the deformation settlement of single-layer bamboo Dendrocalamus asper that using as reinforcement for the peat. The testing at the laboratory and physical model were conducted to fulfill the objective of the study which is to identify the physical properties (water content, specific gravity, organic content, fiber content, degree of decomposition), mechanical properties (consolidation test), and displacement of settlement through physical modeling at the laboratory. The result shows that the soil collected at Kampung Parit Puteri Menangis, Benut, Johor has a moisture content of 672%, specific gravityof 1.23, organic content of 88.34 - 96.19%, fiber content of 38.1%, and categories H4 to H6 (Hemic). The compression index (Cc) was determined in the range of 0.13 to 1.54, the consolidation coefficient (Cv) was determined in the range of 0.62 to 4.925, while the coefficient of compression (Cα) was determined in the range of 0.02 to 0.048. For the displacement of the settlement of peat show the bamboo reinforcement reduce the settlement under different load. The settlement decreased by 59% of the final load 4 kg/m2 during 2 hours in the displacement 9.543 mm to 3.867 mm. It is shown that the properties of peat react with the soil and began to settle down slowly until the reading remained constant.

Estimation of Compression Index of Cohesive-Frictional Soil in Southwest Delhi District Using Statistical Correlations

Estimation of Compression Index of Cohesive-Frictional Soil in Southwest Delhi District Using Statistical Correlations

Prediction of Soil Compression Index using SVM and kNN

Prediction of Soil Compression Index using SVM and kNN

Preparation and Evaluation of Metronidazole Tablets Produced with Different Binders Using Wet Granulation Method

In tablet formulation, binders are essential for ensuring proper powder mix, granulation and overall tablet quality. Variations in binder quality and concentration can impact drug bioavailability, strength and manufacturing processes. The inconsistency in bioavailability and therapeutic response of metronidazole from different manufacturers highlights the importance of binder selection in tablet formulation. This study evaluates the impact of different binding agents on tablet quality. The optimum binder concentration for each of the binders was assessed to obtain suitable concentration that was used to prepare metronidazole tablets. Metronidazole tablets were formulated with four different binder vis, acacia, gelatine, PVP, maize starch at 3% concentration using wet granulation method after which the tablet properties were evaluated. Metronidazole powder exhibited poor flow indices, as indicated by angle of repose: 39.92 ± 1.85, Carr’s compressibility index (CI): 20.13 ± 0.28 and Hausner’s ratio (Hr): 1.26 ± 0.01, whereas its granules exhibited good flow properties. The crushing strength (CS), friability (FR), disintegration time (DT) (CSFR/DT) ratio for batches showed values in 3% binder concentration, indicating higher strength as compared to other concentrations. There was a significant increase (P < 0.05) in the CSFR/DT ratio for gelatine (2.22) in formulation F2 compared to maize starch in Formulation F4. The formulated tablets with the various binders have met with the British Pharmacopeial criteria of 80% drug release from uncoated immediate-release tablets. Amongst the four binders, gelatine was found to be the best in the formulation of robust metronidazole tablets by wet granulation method at an optimised concentration of 3% w/w. Tablets produced with gelatin exhibited greater mechanical strength than those produced with other binders, while also demonstrating a slightly longer DT. Metronidazole tablets produced with gelatine have met the British Pharmacopeial requirements including an acceptable in-vitro drug release profile.

Design Formulation and Evaluation of Anti Migraine Mouth Dissolving Tablets Using Different Super Disintegrants

The main objective of this research was to create and evaluate the efficacy of orally disintegrating tablets containing sumatriptan succinate at a dosage of 25 milligrammes, a medicine commonly prescribed for the treatment of migraines. The tablets are made using the direct compression method. In order to achieve best results, the formulations were enriched with microcrystalline cellulose of varying composition (Avicel PH 102), mannitol as a diluent, crospovidone, croscaramellose, and sodium starch glycollate as superdisintegrants. Carbomer (carbopol 940), Sodium CMC, and Sodium Alginate were among the other excipients that were used. When used at varying doses, these excipients act as disintegrants. In addition, magnesium stearate was used as a substance to reduce friction, while talc was used as a substance to improve flow. We assessed each of the excipients to ascertain their compatibility with the model drug. The findings revealed no occurrence of any physical or chemical interaction. Before compression, the preformulation features of the tablet blend were examined. The criteria considered were bulk density, tapped density, compressibility index, and hausner ratio. An assessment was carried out on central tablets to ascertain their dimensions, firmness, tendency to crumble, variability in weight, rate of disintegration, and uniformity of drug content properties. Furthermore, an investigation was conducted to examine the impact of these variables on the release of the drug. The drug release studies were performed in vitro using the USP dissolving apparatus-II (paddle type) with a phosphate buffer solution at a pH of 6.8. The experiments were conducted at a speed of 50 revolutions per minute at a temperature of 37 degrees Celsius, with a standard deviation of 5 degrees Celsius. The sampling was conducted at consistent intervals of 2, 4, 6, 8, and 10 minutes. After each withdrawal, an equivalent volume of dissolving medium was replaced with the sample. The ultraviolet (UV) method is employed to evaluate the cumulative quantity of medications that have been discharged at different time intervals. Based on the evaluation results, the F-3 trial formulation, which included 6% crospovidone, was selected as the superior formulation among the superdisintegrants. Conversely, the F-10 trial formulation, which included 2% carbopol 940p, was selected as the superior formulation compared to other basic disintegrants.

Multifidelity-based Gaussian process for quasi-site-specific probabilistic prediction of soil properties

Conventional empirical equations for soil properties prediction tend to be site-specific, exhibiting poor reliability and accuracy. Meanwhile, alternative data-driven methods require large datasets for training. To address these issues, this study proposed a novel multifidelity residual neural-network-based Gaussian process (MR-NNGP) modelling framework. A soil property low-fidelity (LF) prediction model is first trained using abundant LF data collected from worldwide sites for generating preliminary estimation. A high-fidelity (HF) model is subsequently trained on sparse HF data from the specific site of interest for calibrating the LF model to make quasi-site-specific predictions. An infinitely wide NN-inspired NNGP is adopted as the baseline algorithm for training LF and HF models. The compression index of clays is selected as an example to examine the capability of the proposed MR-NNGP. The results indicate that the compression index of clays can be well captured by MR-NNGP, exhibiting superior accuracy and reliability compared with one-shot training without using MR modelling and other baseline algorithms such as GP. The MR-NNGP framework alleviates data dependency and improves model performance through hierarchical modelling on relatively simple correlations using a superior algorithm. Unified LF data and efficient hyper-parameter optimization indicate the flexibility for broader applications in various sites worldwide.

Experimental evaluation of stress history effect on compressibility characteristics of lime-stabilized expansive soils

ABSTRACT Lime stabilization has long been identified as an effective method for reducing the swelling potential of expansive soils. Despite numerous studies evaluating the volumetric behaviour of lime-stabilized expansive soils, the influence of stress history variations on deformation characteristics of these soils has not been adequately explored. This study specifically evaluates the impact of stress history conditions on compressibility characteristics of lime-stabilized expansive soils, with special attention to the rebound index at different loading stages. In this regard, one-dimensional consolidation-swell tests were conducted on samples containing different lime percentages (3% to 12%) under various stress history conditions. To include different stress history conditions, overconsolidation ratio (OCR), seating pressure, and loading step were varied during the induction of stress history in the samples. Results showed that OCR and seating pressure significantly influenced both the rebound (increased up to 118%) and compression indices (decreased up to 53%), while the loading step had a negligible impact on the compressibility properties of stabilized soils. Additionally, when comparing the relative importance of investigated parameters, it was revealed that, OCR had the highest influence on the rebound index (up to 118.0% increase), while the compression index was most significantly affected by lime percentage (up to 61.4% decrease).

Ecomorphology of yellowtail lambari (Characiformes: Characidae) in the neotropical semi-arid region, Brazil

The ecomorphological patterns of the Astyanax lacustris in different environments (lotic and lentic) of the semiarid region of Pernambuco were analyzed using 25 linear morphometric measurements on 240 specimens (120 males and 120 females), with standard lengths ranging from 24.25 to 91.50 mm. These data were converted into 16 ecomorphological attributes and correlated with environmental characteristics. The principal component analysis (PCA) explained 81.64% (first and second components) of the data variation, highlighting sexual dimorphism in specimen size and noticeable variation among individuals of the same sex in different environments. Specimens from lotic environments showed higher caudal peduncle compression index (CPCI) values, while the pectoral fin aspect ration (PFAR) was more pronounced in lentic environments. Overall, females exhibited a wide morphometric variation. Analysis of linear morphometry in different water bodies indicated an intrinsic variation related to hydrodynamics linked to sexual dimorphism and water flow speed. Further studies are suggested to investigate whether factors such as macrophytes and different levels of water depth and flow contribute to this morphometric variation of species in the semi-arid region.

Ground Tire Rubber as a Sustainable Additive: Transforming Desert Sand Behavior

Managing waste tires presents a significant challenge globally, particularly in regions experiencing high temperatures and shortage of landfill sites. This issue is affecting countries like Kuwait, where the abundance of waste tires is a major source of environmental and safety risks, particularly during the intensely hot summer months. This extreme heat has sparked numerous fires, leading to substantial air pollution due to thick black smoke. Given the limited disposal options, recycling waste tires and finding practical applications for ground tire rubber (GTR) is essential. To address the challenge, a comprehensive laboratory testing program was conducted, using locally produced rubber aggregates as an additive to Kuwait's local surface sands. Two new variables were examined namely the size and gradation of the GTR, and the density of the compacted mixes. For this purpose, two different sizes of rubber aggregates, fine and coarse produced locally, were utilized, and the impact of relative compaction on the strength and compressibility of the mixtures was investigated by testing samples compacted to the maximum density and to 95% of the maximum density. The results suggest that combining local surface sands with rubber tire additives results in a lighter, more permeable, and compressible material, contributing significantly to sustainable waste management. With 20% rubber additive the maximum dry density decreased by nearly 20%, and the permeability increased by 1.74–3.11 times and the compression index increased by 6.15 and 3.8 times with fine and coarse rubber respectively. The angle of friction remained unchanged at 36° with the addition of coarse rubber and decreased by 3°–4° with fine rubber. The change in behavior although not an increase in the strength and stiffness, offers a range of suitable practical applications in civil engineering and environmental management, including use as a drainage layer, embankment construction on soft ground, earth fill around retaining walls, an additive in asphalt mixes, and in manufacturing compressible tiles for sports facilities.

Correlations between physical properties and compression index of fine-grained soils based on a large dataset

A comprehensive statistical analysis of the correlations between the physical properties and compression index Cc of fine-grained soils, based on a large dataset from the soil testing results of a railway project in the eastern coastal area of Malaysia, is presented in this paper. More than 1000 soil samples covering a wide range of soil types, with physical properties, such as natural water content, initial void ratio, dry density, liquid limit, plasticity index, and mechanical property-compression index, were analyzed using linear and nonlinear regressions. A very high correlation was observed between the natural moisture content, initial void ratio, dry density, and compression index. A strong correlation was found between the plasticity, liquid, and compression indices. Lower and upper boundaries, confining most of the previous correlations, were found between the natural water content and compression index. A comparison of all the correlations showed the natural water content and initial void ratio as the two best properties for predicting the compression index of fine-grained soils.

Experimental study on Corn Straw Fiber (CSF) toughening EPS concrete

The natural Corn Straw Fiber (CSF), it has the advantages of light weight, high strength, good toughness and renewable, can delay the cracking and improve the toughness of cement-based materials. The effects of different mass fractions of CSF and Expanded-Polystyrene (EPS) particles on the compressive strength, flexural strength, splitting tensile strength and their failure modes, load-displacement curves and toughness of EPS concrete were analyzed by full factorial experimental design method. The compressive toughness index (I0, I1) and fracture energy (Gf) were defined to evaluate the effect of CSF on toughening EPS concrete. The results show that the addition of CSF can improve the compressive strength, flexural strength and cracking toughness of EPS concrete to a certain extent. The maximum compressive strength occurred in the E1F3 specimen with a CSF content of 3 % in Group I, which was 1.12 MPa, and the improvement rate was also the highest among the four groups, reaching 69.7 %. The compressive toughness index I1 also reached its maximum in the E1F3 specimen; The maximum flexural strength occurred in the E3F4 specimen with a 4 % CSF content in Group III, which was 0.885Mpa, with the highest improvement rate of 127.38 %. The maximum fracture energy Gf reached 0.827 in the E3F4 specimen. However, another additive, EPS particles, did not significantly improve the physical and mechanical properties of concrete. According to the SEM images and toughening mechanism analysis, it was discovered that tight adhesion between EPS particles and CSF with cement matrix, and the failure mode of CSF was tensile fracture, which could maximize the effect of CSF high tensile toughness. On the basis of mechanical properties and toughening effect, the relationship formulas between variable factors and strength, toughness index were fitted, and the optimal content of EPS and CSF were determined to be 1.3 % and 3 %, respectively.

Analysis of the Consolidation Properties of Soil in the Mucherbari Regulator in Sunamganj

Analysis of the Consolidation Properties of Soil in the Mucherbari Regulator in Sunamganj

Non-Linear Multivariate Analysis with Artificial Neural Network in Estimating Compression Index for Cohesive Soils of Northern Jakarta Coast

This study presents a novel application of artificial neural network (ANN) to develop a model for predicting compression index (Cc) of cohesive soils from their index properties. The model was trained using data from 347 undisturbed samples on a variety of cohesive soils from Northern Jakarta. It takes up to three variables as inputs: specific gravity (Gs), liquid limit (LL), and plastic limit (PL). The model was tested on a separate dataset of 117 samples and found to have a strong capability to predict Cc values when compared to some reference correlations. The ANN model has demonstrated good performance for each set by producing overall error of 29.6%, compared to 38.1% and 30.5% for the empirical formulas. This study shows that the application of ANN offers an essential advancement in this area, helping to overcome the limitation of conventional statistical correlation.