Swelling Research Articles

Development of eco-friendly cellulose acetate films incorporated with Burdock (Arctium lappa L.) root extract

In the present work, a new active film based on cellulose acetate (CA) and Burdock (Arctium lappa L.) root extract (BE) was developed and the effect of different BE concentrations (0, 0.3, 0.6 and 0.9 wt%) on the mechanical, physic-chemical, thermal, antimicrobial and optical properties of CA film were investigated. Results indicated that the antimicrobial activity of CA against Aspergillus niger, Candida albicans, Staphylococcus aureus and Escherichia coli improved with increasing BE concentration. Also, there was an increase in free radical scavenger activity (DPPH), total phenol content (TPC), elongation to break (EB), contact angle (COA), color difference and water vapor transmission rate (WVTR) with BE concentration increasing. While, Young's modulus, tensile strength (TS), solubility (Sol), Water content (WC), and swelling (SW) decreased compared to control film (0 % BE). The porous and non-uniform surface in the films was observed with increasing BE concentration by a scanning electron microscope (SEM). Fourier transform infrared spectroscopic analysis (FTIR) showed that by BE adding to CA film, insignificant changes occurred compared to control film. Differential Scanning Calorimetry (DSC) results indicated that melting temperature and the glass transition temperature of CA films were decreased with BE increase. CA Film with 0.9 % BE had a 99 % weight loss after 60 days. The current research concludes that CA film containing BE can be used as an active, biodegradable and environmentally friendly edible film for food packaging.

Aggregate-Breaking Mechanism Response to Polyacrylamide Application of Purple Soils in Southwestern China Using Le Bissonnais Method

Polyacrylamide (PAM) is a water-soluble polymer with strong cohesiveness and a strong water absorption capacity, and it has been widely used to modify soil structural stability. However, little information is available on the impact of PAM application on the aggregate-breaking process of purple soils in hilly areas of southwestern China. Therefore, the current study aimed to examine the influence of PAM application on the aggregate stability of purple soil in terms of different breakdown mechanisms at different hillslope locations. Three disruptive tests employing the Le Bissonnais method (FW, fast-wetting sieving; SW, slow-wetting sieving; and WS, wet-stirring sieving) were used to determine the mean weight diameter (MWD), geometric mean diameter (GMD), and mass fractal dimension (D) of the soil aggregates, and soil erodibility factor (K) was calculated as an index of soil anti-erodibility. Overall, the major aggregate-breaking mechanism for purple soils was the following: SW (differential swelling) > WS (mechanical breakdown) > FW (slaking). The content of water-stable aggregates (>0.25 mm) obviously rose after PAM application, with the most significant influences shown under FW. A significant difference in MWD was observed between PAM application and without polyacrylamide application (CK) under WS (p < 0.05). However, there was a significant difference in GMD between PAM and CK (p < 0.05) under FW and SW. In comparison with CK, D value in PAM under FW and SW was significantly reduced, mainly at the slope locations of 0 and 20 m. A descending order of FW, WS, and SW was found on the basis of K value at different slope locations. These findings contribute to improved understanding of proper application of soil amendments to control soil and water loss in purple soils.

Preparation and Characterization of Hydrogel Beads for Controlled Release of Amoxicillin

Amoxicillin trihydrate-loaded hydrogel beads were prepared and characterized as a controlled drug delivery system to improve patient compliance. An ionotropic gelation process was used to prepare the hydrogel beads using calcium chloride (CaCl2) as a crosslinking agent. The effects of CaCl2, sodium alginate, poloxamer 407 (PL) concentration, and preparation temperature were investigated. Spherical hydrogel beads were obtained with high encapsulation efficiency (85.74±1.09) %. FTIR analyses confirmed the compatibility of amoxicillin with the used excipients. In vitro swelling and cumulative drug release studies were performed over 24 hours in HCl medium, pH 1.2. Prepara-tion temperature was found to influence both the index of beads swelling (SI) and the cumulative release of amoxicil-lin. The study demonstrated the capability of PL to enhance the cumulative release of amoxicillin, correlating with swelling behavior. The proposed hydrogel beads have the potential as a promising drug delivery system for controlled release of amoxicillin, over 24 hours, and thus reduced dosing frequency.

Cation hydration by confined water and framework-atoms have crucial role on thermodynamics of clay swelling

The swelling capacity and stability of clay play a crucial role in various areas ranging from cosmetics to oil extraction; hence change in their swelling behaviour after cation exchange with the surrounding medium is important for their efficient utilisation. Here we focus on understanding the role of different hydration properties of cation on the thermodynamics of clay swelling by water adsorption. We have used mica as the reference clay, Na^+, Li^+, and H^+ ions as the interstitial cations, and performed grand canonical Monte Carlo simulations of water adsorption in mica pores (of widths d = 4-40 Å). The disjoining pressure (Pi), swelling free energy (Delta Omega ^{ex}), and several structural properties of confined water and ions were calculated to perform a thermodynamic analysis of the system. We expected higher water density in H-mica pores (rho_{ hbox{H}}) due to the smaller size of hbox {H}^+ ions having higher hydration energy. However, the counter-intuitive trend of rho _{hbox{Li}}> rho _{hbox{Na}} > rho_b (bulk density) > rho_{hbox{H}} was observed due to adsorption energy, where the interaction of water with mica framework atoms was also found to be significant. All three mica systems exhibited oscillatory behaviour in the Pi and Delta Omega ^{ex} profiles, diminishing to zero for d ge 11 Å. The Delta Omega ^{ex} for Na-mica is characterised by global minima at d=6 {hbox {AA}} corresponding to crystalline swelling with significant and multiple barriers for crystalline swelling to osmotic swelling (d > 12 Å). A shift in the location of global minima of Delta Omega ^{ex} towards the higher d values and Delta Omega ^{ex} becoming more repulsive is observed in the increasing order of hydration energy of hbox {Na}^+, hbox {Li}^+, and hbox {H}^+ ions. The Delta Omega ^{ex} > 0 for all d in the H-mica system thus favours osmotic swelling. We found that the Na^+ ions hydrate more surface oxygens, act as anchors, and hold the mica pore together (at smaller d), by sharing hydrating water with ions of the opposite side, forming an electrostatically connected mica-Na-water-Na-mica bridge. The Li^+ ions do hydrate surface oxygen atoms, albeit in lesser numbers, and sharing of hydration shell with nearby Li^+ ions is also minimum. Hydration by surface atoms and water sharing, both, are minimum in the H^+ ion case, as they are mostly present in the center of the pore as diffusive ions, thus exerting a consistent osmotic pressure on the mica frameworks, favouring swelling.

Effect of bamboo species and pre-treatment method on physical and mechanical properties of bamboo processed by flattening-densification

In this study, Dendrocalamus asper and Phyllostachys edulis (Moso) bamboo were subjected to a two-phase process of flattening and densification using a non-confined thermo-hydro mechanical (THM) system (composed of two hot plates without lateral limit) to redesign bamboo's microstructure and improve its performance for applications in panel manufacturing. Different softening procedures using pre-treatments with water under vacuum/pressure conditions using a vacuum of −650 mmHg and a pressure of approximately 3100 mmHg (V/P) and boiling treatment for 1 h at 100 °C (B) before flattening were studied. All groups were flattened, dried at room temperature, and densified at the same processing parameters. The microstructural, physical, and bending properties of the obtained flattened-densified bamboo using these two pretreatments were examined and compared with untreated-undensified (UN) bamboo and samples flattened-densified in an equilibrium moisture content (EQ). The results of bending tests, comparing to the un-processed bamboo, revealed that the flattening process combined with densification promote an average increase in the Modulus of Rupture (MOR), (56% and 66%), Modulus of Elasticity (MOE) (48% and 78%), Limit of Proportionality (41% and 86%), and Specific Energy (126% and −12%) in the case of D. asper, and Moso respectively. However, the applied process increased the thickness swelling (SW) and water absorption (WA). This negative effect was more pronounced in the case of Moso compared to D. asper. The flattened-densified Moso using any type of applied pretreatments presented an average of 64% of WA and 35% of SW, while these values for D. asper bamboo were 28% and 19% of WA and SW respectively. In addition, boiling the bamboo in water as a pre-treatment prior to densification reduces the cracks number compared to the other pre-treatments, resulting in higher MOR, MOE, and dimensional stability.

Karakterisasi sifat fungsional pati sagu (Metroxylon sagu Rottb) dengan modifikasi taut silang sebagai bahan cangkang kapsul [Characterization of sago starch (Metroxylon sagu Rottb) functional properties with cross linking modification ascapsule shell

This study aims to determine the functional properties of natural and modified sago starch as a substitute for raw material for capsule shells from animal gelatin. Rumbia starch (Metroxylon sagu Rottb) or sago starch has good biodegradability, edibility, b iocompatibility, attractive appearance, and able to withstand oxygen and physical disturbances. In this study, the optimization of the functional properties of gelatin was carried out, including viscosity, gel fraction, water vapor transmission, and swelli ng degree test. The stages of this research were modification of sago starch, film printing and viscosity testing, gel fraction, water vapor transmission, and swelling degree test. The results showed that the gel fraction content was 51.8% (sago starch (PS ) + Poly Vinyl Alcohol (PVA)) - 81.6% (modified sago starch (PSM) + kaolin), the swelling degree was 1.41% (PS). +kaolin) – 2.32% (PSM+kaolin), viscosity of 2 cp (PS+PVA/kaolin) – 3220 cp (PSM+kaolin)), and water vapor transmission of 58.33 g/m2h – 566.25 g/m2h. The best result from cross linking was the application of modified sago starch (PSM) plus kaolin which gave the highest value for the gel fraction, degree of swelling and viscosity parameters.

Adipose-Derived Stem Cells Growth and Proliferation Enhancement Using Poly(Lactic-co-Glycolic Acid) (PLGA)/Fibrin Nanofiber Mats

Introduction: A synthetic biomaterial, such as poly(lactic-co-glycolic acid) (PLGA) with superior mechanical properties, along with a natural polymer such as fibrin, which facilitates cell attachment and enhances biocompatibility, can be used in the production of novel composite tissue engineering scaffolds. In this study, we fabricated a PLGA/Fibrin scaffold which was evaluated to the enhancement of adipose-derived stem cells' growth and proliferation. Materials and Methods: 10% polymer solutions with different ratios of PLGA:Fibrin, including 10:0, 9:1, 8:2, and 7:3, were prepared and used in the production of aligned and unaligned electrospun nanofiber scaffolds. Human adipose-derived stem cells (h-ADSCs) were cultured on the scaffolds and they were characterized using FTIR, EDX, SEM, mechanical, hydrophilic, degradation, water absorption, and biocompatibility tests. Results: The obtained scaffolds consisted of homogeneous fibers, without any beads and water droplets. The percentage of porosities and internal correlation of the cavities are not significantly different between aligned and unaligned electrospun scaffolds (P>0.05) and by adding fibrin, these properties are improved, while tensile strength and elasticity are decreased. All the scaffolds are hydrophobic and the highest and lowest swelling rates belong to PLGA/30%Fibrin scaffolds and pure PLGA scaffolds (more than 90% and less than 45%, respectively). There is a significant difference in degradation rates between fibrin-contained scaffolds and pure PLGA scaffolds. Moreover, compared with aligned electrospun scaffolds, a higher degradation rate of unaligned ones was observed. Conclusions: Considering the results of SEM and bio-compatibility experiments, the aligned electrospun PLGA/10%Fibrin scaffold with numerous spindle shape h-ADSCs and unaligned electrospun PLGA/20%Fibrin scaffold with lots of spindle shape cells together with sort of round shape cells are introduced as the optimal options.

Host rock peculiarities and influence of major structures on gold and base metal sulfide mineralization in northern Pakistan

For decades, the streams and rivers in northern areas of Pakistan are being explored for gold but the source rock for primary gold is yet to be located. Recent geological surveys have identified several areas for follow-up study for Cu-Au mineralization in Chitral and Gilgit-Baltistan regions. The rocks exposed at various localities are variably altered and/ or mineralized and intensely deformed, which mostly include diorite, granodiorite, greenschists, limestones and undeformed volcanic rocks and granitoids of the Kohistan island arc. The results of petrographic and X-ray diffraction (XRD) analyses of a variety of representative rock samples from a number sites have revealed that mineralization in the Chitral and Gilgit-Baltistan regions is dominantly in the form of pyrite, tetrahedrite, chalcopyrite and galena with subordinate amounts of magnetite, malachite and azurite. The associated/ gangue minerals include albite, quartz, actinolite, biotite, chlorite, epidote, calcite, garnet, illite and titanite (sphene). Diffraction patterns of glycolated samples did not show the existence of swelling clay (e.g., smectite). Sericitic, chloritic and carbonatic alterations have been observed in the studied altered rocks. Mass balance calculations indicate that most of the sulfide-bearing samples are enriched in Cu, Au, Sb, As and Pb and depleted in the rest of the metals reflecting differences in elements mobility during the ore-forming processes. Some of the mineralized rocks especially limestone have experienced a significant volume change due to mobilization of some of the major element oxides e.g. CaO, Fe2O3, SiO2 and ore-forming components e.g. Cu and Pb. The mineralization is of epithermal type in most of the investigated sites, however a few areas show ore formation though orogenic processes and very rarely the ore deposit displays features of the volcanogenic massive sulfide type. Some of the areas are quite promising with respect to their ore element contents and the highly mineralized zones lie in close proximity to major structures in the region. Besides, results from the current study indicate that the mineralization shows close spatial association and hence a strong genetic link with strike slip faults especially where they bend and merge together.

Mechanical properties and microstructures of stabilised dredged expansive soil from coal mine

Expansive soil is the most predominant geologic hazard which shows a large amount of shrinkage and swelling with changes in their moisture content. This study investigates the macro-mechanical and micro-structural behaviours of dredged natural expansive clay from coal mining treated with ordinary Portland cement or hydrated lime addition. The stabilised expansive soil aims for possible reuse as pavement materials. Mechanical testing determined geotechnical engineering properties, including free swelling potential, California bearing ratio, unconfined compressive strength, resilient modulus, and shear wave velocity. The microstructures of treated soils are observed by scanning electron microscopy, x-ray diffraction, and energy dispersive spectroscopy to understand the behaviour of the expansive clay blended with cement and lime. Test results confirmed that cement and lime are effective agents for improving the swelling behaviour and other engineering properties of natural expansive clay. In general, chemical treatments reduce the swelling and increase the strength and modulus of expansive clay, subjected to chemical content and curing time. Scanning electron microscopy analysis can observe the increase in formation of particle clusters with curing period, and x-ray diffraction patterns display hydration and pozzolanic products from chemical particles. The correlations of mechanical properties and microstructures for chemical stabilised expansive clay are recommended.

Three dimensional seismic deformation-shear strain-swelling performance of America-California Oroville Earth-Fill Dam

Structural design of the vertical displacements and shear strains in the earth fill (EF) dams has great importance in the structural engineering problems. Moreover, far fault earthquakes have significant seismic effects on seismic damage performance of EF dams like the near fault earthquakes. For this reason, three dimensional (3D) earthquake damage performance of Oroville dam is assessed considering different far-fault ground motions in this study. Oroville Dam was built in United States of America-California and its height is 234.7 m (770 ft.). 3D model of Oroville dam is modelled using FLAC3D software based on finite difference approach. In order to represent interaction condition between discrete surfaces, special interface elements are used between dam body and foundation. Non-reflecting seismic boundary conditions (free field and quiet) are defined to the main surfaces of the dam for the nonlinear seismic analyses. 6 different far-fault ground motions are taken into account for the full reservoir condition of Oroville dam. According to nonlinear seismic analysis results, the effects of far-fault ground motions on the nonlinear seismic settlement and shear strain behaviour of Oroville EF dam are determined and evaluated in detail. It is clearly seen that far-fault earthquakes have very significant seismic effects on the settlement-shear strain behaviour of EF dams and these earthquakes create vital important seismic damages on the swelling behaviour of dam body surface. Moreover, it is proposed that far-fault ground motions should not be ignored while modelling EF dams.

Painless lip swelling in a child.

Painless lip swelling in a child.

Paget-Schroetter Syndrome with Asymptomatic Pulmonary Embolism in a Collegiate Baseball Pitcher

Introduction: An 18-year old baseball player with a history of chronic right arm swelling presented with a 1-day history of right arm soreness, swelling, and discoloration. The patient was found to have right upper extremity deep venous thrombosis (DVT) and bilateral lower lobe pulmonary emboli. The patient was diagnosed with Paget-Schroetter Syndrome (PSS), also known as effort thrombosis, which is a rare subset of thoracic outlet syndrome in which DVT of the upper extremity occurs resulting from repetitive microtrauma and compression of the subclavian vein. The patient was treated with …

Assessment of the swelling potential of Baghmisheh marls in Tabriz, Iran

Tabriz is a large Iranian city and the capital of the East Azerbaijan province. The bed rock of this city is mainly consisted of marl layers. Marl layers have some outcrops in the northern and eastern parts of city that mainly belong to the Baghmisheh formation. Based on their colors, these marls are classified into three types: yellow, green, and gray marls. The city is developing toward its eastern side wherein various civil projects are under construction including tunnels, underground excavation, and high-rise building. In this regard, the swelling behavior assessment of these marls is of critical importance. Also, in lightweight structures with foundation pressure less than swelling pressure, several problems such as walls cracking and jamming of door and windows may occur. In the present study, physical properties and swelling behavior of Baghmisheh marls are investigated. According to the X-ray diffractometer (XRD) results, the marls are mainly composed of Illite, Kaolinite, Montmorillonite, and Chloride minerals. Type and content of clay minerals and initial void ratio have a decisive role in swelling behavior of these marls. The swelling potential of these marls was investigated using one-dimensional odometer apparatus under stress level up to 10 kPa. The results showed that yellow marls have high swelling potential and expansibility compared to the other marls. In addition, green and gray marls showed intermediate and low swelling potential and swelling pressure, respectively.

Alkali-activated GGBS and enzyme on the swelling properties of sulfate bearing soil

Use of cement in stabilizing the sulfate-bearing clay soils forms ettringite/ thaumasite in the presence of moisture leads to excessive swelling and causes damages to structures built on them. The development and use of non-traditional stabilisers such as alkali activated ground granulated blast-furnace slag (AGGBS) and enzyme for soil stabilisation is recommended because of its lower cost and the non detrimental effects on the environment. The objective of the study is to investigate the effectiveness of AGGBS and enzyme on improving the volume change properties of sulfate bearing soil as compared to ordinary Portland cement (OPC). The soil for present study has been collected from Tilda, Chhattisgarh, India and 5000 ppm of sodium sulfate has been added. Various dosages of the selected stabilizers have been used and the effect on plasticity index, differential swell index and swelling pressure has been evaluated. XRD, SEM and EDX were also done on the untreated and treated soil for identifying the mineralogical and microstructural changes. The tests results show that the AGGBS and enzyme treated soil reduces swelling and plasticity characteristics whereas OPC treated soil shows an increase in swelling behaviour. It is observed that the swell pressure of the OPC-treated sulfate bearing soil became 1.5 times higher than that of the OPC treated non-sulfate soil.

Modelling of AAm-co-alginate hydrogels swelling kinetics

Modelling of AAm-co-alginate hydrogels swelling kinetics

Effects of denaturisation of rice bran and route of synthesis of RB-modified UF adhesive system on eco-performance of agro-based composites

Purpose The purpose of this paper is to examine the effects of denaturised rice bran (RB) and route of its incorporation during synthesis of urea-formaldehyde adhesive, on the performance of the resulting adhesive, especially viscosity, free-formaldehyde (HCHO) and quality of the produced bagasse-based composites, in comparison with those produced from commercial urea formaldehyde (UF) and RB-added UF. Design/methodology/approach The experiments were carried out using different denaturised RB at different percentages (1-5 per cent) and pH’s (9-11 per cent). These denaturised RB were incorporated at the last synthesis stage of UF synthesis process. The assessment was carried out on both the viscosity and environmental safety of the adhesive system, as well as the quality of the manufactured bagasse-based composites, of the particleboards (static bending, internal bond (IB) strength and water resistance properties), in comparison to commercial UF and RB added to UF. The performance of the adhesive system was evidenced by the thermogravimetric analysis and differential scanning calorimetry analyses. Findings The results showed that maximum static bending [modulus of rupture (MOR) and modulus of elasticity (MOE)], IB strength and water resistance properties of the resulted wood product accompanied the incorporating 5 per cent of the denaturised RB (pH = 9.0), at the last synthesised stage of UF synthesis process. Where, this synthesis process provided adhesive with viscosity nearly approaching to commercial UF adhesive, and reduced the free-HCHO of adhesive and board by approximately 56 and 49 per cent, respectively. For mechanical and water resistance properties, it provided board with 24.5 MPa MOR, 3,029 MPa MOE, 0.64 MPa IB, 11 per cent swelling (SW) and 20.5 per cent absorption. These properties fulfil the requirements of high grade particleboards American National Standard Institute (ANSI) A208.1, especially with respect to static bending values and water swelling property. Research limitations/implications Incorporating 5 per cent of pre-denaturised RB, at pH 9.0, in wet form, and in the last stage of synthesis UF, provided adhesive system with convenient viscosity together with lower free-HCHO and acceptable board properties, compared with that produced from commercial UF, or adding denaturised RB to already synthesised UF. For the mechanical (MOR, MOE and IB) and water resistance properties (SW per cent and absorption per cent) of the produced composite are complied the standard values of H-3 grade of particleboard. Practical implications Promising adhesive system is resulted from incorporating 5 per cent of pre-denaturised RB at pH 9.0, in wet form, during last stage of UF synthesis process. Social implications Incorporating the RB by-product of oil production to commercial UF or during synthesis of UF will be benefit for saving the healthy of wood co-workers, and motivating the wood mill to export its wood products. Originality/value The article provides a potential simple way to solve the drawback of increasing the viscosity of UF, as a result of adding RB, via incorporating the RB during synthesis process. The viscosity of the synthesised RB-modified UF approaches RB-free UF, and consequently the adhesive system easily penetrates through agro-fibres, and provides good bonding behaviour and high performance wood product (both quality and environmental by minimising formaldehyde emission or toxic gasses during board formation).

Suppurative boggy swelling over scalp

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Suppurative boggy swelling over scalp.

Suppurative boggy swelling over scalp.

Metal adsorption of gamma-irradiated carboxymethyl cellulose/polyethylene oxide blend films

ABSTRACTBlend films of different ratios of carboxymethyl cellulose (CMC)/polyethylene oxide (PEO) were prepared by the solution casting method. To investigate the effect of irradiation on all properties of prepared blend, it was exposed to different gamma irradiation doses (10, 20, and 30 kGy). Physical properties such as gel fraction (GF) (%) and swelling (SW) (%) were investigated. It was found that the GF (%) increases with increasing irradiation dose up to 20 kGy, while SW (%) decreases with an increase in the irradiation doses for all blend compositions. Moreover, the structural and mechanical properties of the prepared films were studied. The results of the mechanical properties obtained showed that there is an improvement in these properties with an increase in both CMC and irradiation dose up to 20 kGy. The efficiency of metal ions uptake was measured using a UV spectrophotometer. The prepared films showed good tendency to absorb and release metal ions from aqueous media. Thus, the CMC/PEO film can be used in agricultural domain.

Обзор конструкций набухающих пакеров и возможности их применения на месторождениях Азербайджана

Обзор конструкций набухающих пакеров и возможности их применения на месторождениях Азербайджана