• Title/Summary/Keyword: Permeability Factors

Search Result 308, Processing Time 0.028 seconds

Effect of water temperature and soil type on infiltration

  • Mina Torabi;Hamed Sarkardeh;S. Mohamad Mirhosseini;Mehrshad Samadi
    • Geomechanics and Engineering
    • /
    • v.32 no.4
    • /
    • pp.445-452
    • /
    • 2023
  • Temperature is one of the important factors affecting the permeability of water in the soil. In the present study, the impact of water temperature on hydraulic conductivity (k) with and without coarse aggregations by considering six types of soils was analyzed. Moreover, the effect of sand and gravel presence in the soil was investigated through the infiltration based on constant and inconstant water head experiments. Results indicated that by increasing the water temperature, adding gravel to sandy soil caused the hydraulic conductivity to raise. It is supposed that the gravel decreased the contact surface between the water and the soil aggregates. It is deduced that due to decreasing kinetic energy, k tends to have lower values. Furthermore, adding the sand to sandy silt-clay soil showed that the sand did not have a marginal effect on the variation of k since the added sand cannot increase the contact surface like gravel. Finally, increasing the main diameter of the soil will increase the effect of the water temperature on hydraulic conductivity.

Facile Synthesis of Bio-Composite Films Obtained from Sugarcane Bagasse and Cardboard Waste

  • Satish Kumar Singh;Sweety Verma;Himanshu Gupta;Avneesh Kumar Gehlaut;Suantak Kamsonlian;Surya Narain Lal;Ankur Gaur;Sanjeev Maken
    • Korean Chemical Engineering Research
    • /
    • v.61 no.4
    • /
    • pp.584-590
    • /
    • 2023
  • In this study, we focus on the recycling of cardboard waste and sugarcane bagasse (SCB) for the preparation of carboxymethyl cellulose (CMC) and its conversion into a biodegradable film. Sodium alginate (SA) was added to form a biodegradable composite film. SA was used to increase film permeability. Glycerol, which is a plasticizer, was used to increase the tensile strength (TS) and film expansion. To characterize the CMC, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were used. The addition of olive oil to the CMC-SA matrix highlighted its antimicrobial property against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). A slight decrease in tensile strength was observed with the addition of olive oil (OO), which improved the functional properties of the control films as well as lowered moisture content and water solubility. But considering all other factors, the composite films obtained from sugarcane bagasse and cardboard waste incorporated with olive oil are suitable for applications in the field of food packaging.

Methods on improvements of the poor oral bioavailability of ginsenosides: Pre-processing, structural modification, drug combination, and micro- or nano- delivery system

  • Qi-rui Hu;Huan Hong;Zhi-hong Zhang;Hua Feng;Ting Luo;Jing Li;Ze-yuan Deng;Fang Chen
    • Journal of Ginseng Research
    • /
    • v.47 no.6
    • /
    • pp.694-705
    • /
    • 2023
  • Panax ginseng Meyer is a traditional Chinese medicine that is widely used as tonic in Asia. The main pharmacologically active components of ginseng are the dammarane-type ginsenosides, which have been shown to have anti-cancer, anti-inflammatory, immunoregulatory, neuroprotective, and metabolic regulatory activities. Moreover, some of ginsenosides (eg, Rh2 and Rg3) have been developed into nutraceuticals. However, the utilization of ginsenosides in clinic is restrictive due to poor permeability in cells and low bioavailability in human body. Obviously, the dammarane skeleton and glycosyls of ginsenosides are responsible for these limitations. Therefore, improving the oral bioavailability of ginsenosides has become a pressing issue. Here, based on the structures of ginsenosides, we summarized the understanding of the factors affecting the oral bioavailability of ginsenosides, introduced the methods to enhance the oral bioavailability and proposed the future perspectives on improving the oral bioavailability of ginsenosides.

Factors affecting hydraulic anisotropy of soil

  • Nurly Gofar;Alfrendo Satyanaga;Gerarldo D. Aventian;Gulnur Pernebekova;Zhanat Argimbayeva;Sung-Woo Moon;Jong Kim
    • Geomechanics and Engineering
    • /
    • v.36 no.4
    • /
    • pp.343-353
    • /
    • 2024
  • The hydraulic anisotropic behavior of unsaturated soil has not been fully explored in relation to the grain-size distribution. The present study conducted laboratory assessments to examine the hydraulic anisotropy condition of statically compacted specimens in various initial states. The investigation incorporated the concept of hydraulic anisotropy by employing two discrete forms of soil stratification: horizontal-layering (HL) and vertical-layering (VL). The examined soils comprised sandy silt and silty sand, exhibiting either unimodal or bimodal soil-water characteristic curve (SWCC). This study aimed to investigate the potential correlation between the hydraulic anisotropy ratio and soil properties. The present study established a correlation between the hydraulic anisotropy ratio and several soil parameters, including fine content, dry density, plastic limit, and liquid limit. The study results indicate a non-linear relationship between the percentage of fine and dry density in soils with unimodal and bimodal soil-water characteristic curve (SWCC) and hydraulic anisotropy ratio.

Prediction of pharmacokinetics and drug-drug interaction potential using physiologically based pharmacokinetic (PBPK) modeling approach: A case study of caffeine and ciprofloxacin

  • Park, Min-Ho;Shin, Seok-Ho;Byeon, Jin-Ju;Lee, Gwan-Ho;Yu, Byung-Yong;Shin, Young G.
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.21 no.1
    • /
    • pp.107-115
    • /
    • 2017
  • Over the last decade, physiologically based pharmacokinetics (PBPK) application has been extended significantly not only to predicting preclinical/human PK but also to evaluating the drug-drug interaction (DDI) liability at the drug discovery or development stage. Herein, we describe a case study to illustrate the use of PBPK approach in predicting human PK as well as DDI using in silico, in vivo and in vitro derived parameters. This case was composed of five steps such as: simulation, verification, understanding of parameter sensitivity, optimization of the parameter and final evaluation. Caffeine and ciprofloxacin were used as tool compounds to demonstrate the "fit for purpose" application of PBPK modeling and simulation for this study. Compared to caffeine, the PBPK modeling for ciprofloxacin was challenging due to several factors including solubility, permeability, clearance and tissue distribution etc. Therefore, intensive parameter sensitivity analysis (PSA) was conducted to optimize the PBPK model for ciprofloxacin. Overall, the increase in $C_{max}$ of caffeine by ciprofloxacin was not significant. However, the increase in AUC was observed and was proportional to the administered dose of ciprofloxacin. The predicted DDI and PK results were comparable to observed clinical data published in the literatures. This approach would be helpful in identifying potential key factors that could lead to significant impact on PBPK modeling and simulation for challenging compounds.

Study on the Fabric Trend in Hi-Tech Functional Active Sportswear (하이테크 기능성 액티브 스포츠웨어의 소재경향에 관한 연구)

  • Baik Cheon-Eui;Kim So-Young
    • Journal of the Korea Fashion and Costume Design Association
    • /
    • v.7 no.1
    • /
    • pp.55-63
    • /
    • 2005
  • The outcome of modem sports events are reliant on not only the athletic ability and technology of individual players but their sportswear proterties. State-of-the-Hitech sportswear has started to be introduced in the 1950s, and in addition to the athletic capability of players, sportswear is one of the primary factors to affect the results of sports games, as a wide variety of Hi-Tech functional materials have come out since the 1990s. The purpose of this study was to development into the concept of active sportswear, to sort out hitech functional product lines in this field, to look into sports stars and Hi-Tech functional sports brands, and finally to identify the major characteristics of recent active sportswear. The result of this study were as follows: 1. There were largely four characteristics in recent functional sportswear materials: fast-drying cooling, minimized resistance, ultralight comfortableness, and water vapor permeable/waterproof function. 2. Besides the athletic capability and technology of players, Hi-Tech functional products are one of the major factors to determine the outcome of modem sports events. Functional synthetic fiber is preferred, instead of cotton, since the former is easier to manage and retains humidity better. 3. The major features of recent trend in active sportswear products are, functional, diversity and value. That is, those products are functional, since they are easy to manage and retain proper humidity, and they are for multipurpose, since they are fashionable and practical at the same time. And they are valuable, being expensive but appropriate for the movement of the body and having a high quality.

  • PDF

Factors Involved with the Incidence of Black Stain in Pear Fruits During Growing Season (배 과실의 생육기에 발생하는 과피얼룩과 발생 요인)

  • Kim, Jeam-Kuk;Park, Young-Seob;Seo, Hyeong-Ho;Lee, Han-Chan;Lee, Jung-Sup
    • Research in Plant Disease
    • /
    • v.12 no.3
    • /
    • pp.164-167
    • /
    • 2006
  • Potential factors favoring black stains during fruit development in Pyrus serotina was investigated. Black stain occurred from young fruit till harvest. The color of the affected fruits in early stage was black or light reddish brown, but turned to light brown over time. Fruit bags with lower light transmission and inner bags with poor aeration stimulated the symptoms, and high water permeability of the bags increased the black stain. Much rain and/or poor light transmission and aeration within the canopies also favored the occurrence of black stain. Diminution of pathogenic fungi density by lime sulfur was more effective than the canopy spray of fungicide for the prevention of black stain.

Factors Influencing Rooting and Growth in Stem-Cut Planting of Ligusticum chuangxiong Hort (천궁(川芎)의 줄기 삽식시 발근(發根)과 생육(生育)에 영향(影響)하는 요인(要因))

  • Ohk, H.C.;Lee, H.S.;Chae, Y.A.
    • Korean Journal of Medicinal Crop Science
    • /
    • v.5 no.2
    • /
    • pp.119-125
    • /
    • 1997
  • This study was carried out to know the factors affecting rooting and growth in stem cutting of Ligusticum chuangxiong for mass propagation. The results indicated that : (1) Rooting and growth were better in perlite which has higher air permeability. (2) Sub-irrigation with 15min long with 30min interval was more favorable for growth. (3) Proper tempeature for rooting and growth ranged from $25^{\circ}C\;to\;30^{\circ}C$ while photoperiod had no effect on rooting and growth.

  • PDF

A Study of Dewatering and Filtration on Woven Geotextile Tube (직포 지오텍스타일 튜브의 여과와 탈수에 대한 연구)

  • Kim, Tae-Hyung;Jung, Soo-Jung
    • Journal of the Korean Geosynthetics Society
    • /
    • v.5 no.2
    • /
    • pp.31-37
    • /
    • 2006
  • The purposes of this paper are to study the use possibility of geotextile tubes for dewatering of high water content sludges and sediments and to evaluate affecting factors on dewatering. To do this, pressure filtration tests are conducted on four high water content materials with two geotextiles under two filtration pressures. Based on the test results, although woven geotextile tubes are not satisfied the soil retention criteria used in filter design commonly, a great portion of fines are retained by filter cake formation on geotextile tube's upstream side, but also after formation of filter cake, the permeability drops sharply. Higher filtration pressure tends to increase dewatering rate, but has very little effect on filtration efficiency. Dewatering capacity is affected by several factors which are related to the geotextile, but the property of sludge appears to be the dominant control factor for dewatering efficiency.

  • PDF

Injectable hydrogels delivering therapeutic agents for disease treatment and tissue engineering

  • Lee, Jin Hyun
    • Biomaterials Research
    • /
    • v.22 no.4
    • /
    • pp.235-248
    • /
    • 2018
  • Background: Injectable hydrogels have been extensively researched for the use as scaffolds or as carriers of therapeutic agents such as drugs, cells, proteins, and bioactive molecules in the treatment of diseases and cancers and the repair and regeneration of tissues. It is because they have the injectability with minimal invasiveness and usability for irregularly shaped sites, in addition to typical advantages of conventional hydrogels such as biocompatibility, permeability to oxygen and nutrient, properties similar to the characteristics of the native extracellular matrix, and porous structure allowing therapeutic agents to be loaded. Main body: In this article, recent studies of injectable hydrogel systems applicable for therapeutic agent delivery, disease/cancer therapy, and tissue engineering have reviewed in terms of the various factors physically and chemically contributing to sol-gel transition via which gels have been formed. The various factors are as follows: several different non-covalent interactions resulting in physical crosslinking (the electrostatic interactions (e.g., the ionic and hydrogen bonds), hydrophobic interactions, ${\pi}$-interactions, and van der Waals forces), in-situ chemical reactions inducing chemical crosslinking (the Diels Alder click reactions, Michael reactions, Schiff base reactions, or enzyme-or photo-mediated reactions), and external stimuli (temperatures, pHs, lights, electric/magnetic fields, ultrasounds, or biomolecular species (e.g., enzyme)). Finally, their applications with accompanying therapeutic agents and notable properties used were reviewed as well. Conclusion: Injectable hydrogels, of which network morphology and properties could be tuned, have shown to control the load and release of therapeutic agents, consequently producing significant therapeutic efficacy. Accordingly, they are believed to be successful and promising biomaterials as scaffolds and carriers of therapeutic agents for disease and cancer therapy and tissue engineering.