Search results for: swelling

Authors: Juliana A. Knocikova, Yann Bouret, Médéric Argentina, Laurent Counillon

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Cell volume, together with membrane potential and intracellular hydrogen ion concentration, is an essential biophysical parameter for normal cellular activity. Cell volumes can be altered by osmotically active compounds and extracellular tonicity. In this study, a simple mathematical model of osmotically induced cell swelling and shrinking is presented. Emphasis is given to water diffusion across the membrane. The mathematical description of the cellular behavior consists in a system of coupled ordinary differential equations. We compare experimental data of cell volume alterations driven by differences in osmotic pressure with mathematical simulations under hypotonic and hypertonic conditions. Implications for a future model are also discussed.

Keywords: Eukaryotic cell, mathematical modeling, osmosis, volume alterations.

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Authors: E. Moroydor Derun, Z. Eslek, S. Piskin

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Hypericum perforatum L. is a member of the Hypericaceae (Guttiferae) family and commonly known as St. John’s wort. There is a growing interest in this medicinal plant because of the constituents of this genus. A number of species have been shown to possess various biological activities such as antiviral, wound healing, analgesic, hepatoprotective, antimicrobial and antioxidant activities and also have therapeutic effects on burns, bruises, swelling, anxiety and mild to moderate depression. In this study, the aerial parts of Hypericum perforatum L. are extracted and the main and effective constituents are determined. The analysis of the extracts was performed by GC-MS and LC-MS. As a next step, it is aimed to investigate the usage of the main constituents of the medicinal plant.

Keywords: Hypericaceae, Hypericum perforatum L., GC-MS, Guttiferae, LC-MS, Medicinal plant, St. John’s wort.

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Authors: H. Ahmed, A. Persson, L. Sundqvist, B. Biorkman

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Numerous amounts of metallurgical dusts and sludge containing iron as well as some other valuable elements such as Zn, Pb and C are annually produced in the steelmaking industry. These alternative iron ore resources (fines) with unsatisfying physical and metallurgical properties are difficult to recycle. However, agglomerating these fines to be further used as a feed stock for existing iron and steelmaking processes is practiced successfully at several plants but for limited extent.

In the present study, briquettes of integrated steelmaking industry waste materials (namely, BF-dust and sludge, BOF-dust and sludge) were used as feed stock to produce direct reduced iron (DRI). Physical and metallurgical properties of produced briquettes were investigated by means of TGA/DTA/QMS in combination with XRD. Swelling, softening and melting behavior were also studied using heating microscope.

Keywords: Iron and Steel Wastes, Recycling, Self-Reducing Briquettes, Thermogravimetry.

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Authors: Parizad Sheikhi, Mohammad Talaeipour

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the effects of refining and alkaline chemicals on potential of recycling bleached chemical pulp of bagasse were investigated in this study. Recycling was done until three times. Handsheet properties such as, apparent density, light scattering coefficient, tear index, burst index, breaking length, and fold number according to TAPPI standard were measured. Water retention value also was used to considering the treatments during recycling. Refining enhanced the strength of recycled pulp by increasing fiber flexibility and swelling ability, whereas by applying chemical treatment didn't observe any improvement. The morphology of recycled fiber was considered with scanning electron microscopy (SEM).

Keywords: Bagasse pulp, chemical treatment, recycling, refining, scanning electron microscopy, water retention value.

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Authors: Shatirah Akib, Teuku K. Syamsura, S.M. Shirazi, Moatasem M. Fayyadh, Budhi Primasari

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The purpose of this paper is to summarize the following protection of scouring countermeasures by using Bentonite-Enhanced Sand (BES) mixtures. The concept of underground improvement is being used in this study to reduce the void of the sand. The sand bentonite mixture was used to bond the ground soil conditions surrounding the pile of integral bridge. The right composition of sand bentonite mixture was proposed based on previous findings. The swelling effect of bentonite also was investigated to ensure there is no adverse impact to the structure of the integral bridge. ScourScour, another name for severe erosion, occurs when the erosive capacity of water resulting from natural and manmade events exceeds the ability of earth materials to resist its effects. According to AASHTO LRFD Specifications (Section C3.7.5), scour is the most common reason for the collapse of highway bridges in the United States

Keywords: bentonite, integral bridge, possible protection, scouring

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Authors: Vanchai Laemlaksakul

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This research was to evaluate a technical feasibility of making single-layer experimental particleboard panels from bamboo waste (Dendrocalamus asper Backer) by converting bamboo into strips, which are used to make laminated bamboo furniture. Variable factors were density (600, 700 and 800 kg/m3) and temperature of condition (25, 40 and 55 °C). The experimental panels were tested for their physical and mechanical properties including modulus of elasticity (MOE), modulus of rupture (MOR), internal bonding strength (IB), screw holding strength (SH) and thickness swelling values according to the procedures defined by Japanese Industrial Standard (JIS). The test result of mechanical properties showed that the MOR, MOE and IB values were not in the set criteria, except the MOR values at the density of 700 kg/m3 at 25 °C and at the density of 800 kg/m3 at 25 and 40 °C, the IB values at the density of 600 kg/m3, at 40 °C, and at the density of 800 kg/m3 at 55 °C. The SH values had the test result according to the set standard, except with the density of 600 kg/m3, at 40 and 55 °C. Conclusively, a valuable renewable biomass, bamboo waste could be used to manufacture boards.

Keywords: Particleboard, Urea Formaldehyde Resin, BambooWaste

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Authors: Ogunsina Babatunde, Aregbesola Omotayo, Adebayo Adewale, Odunlami Johnson

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The physical properties of nine Nigerian staple food flours related to bulk handling and processing were investigated following standard procedures. The results showed that the moisture content, bulk density, angle of repose, water absorption capacity, swelling index, dispersability, pH and wettability of the flours ranged from 9.95 to 11.98%, 0.44 to 0.66 g/cm³, 31.43 to 39.65^o, 198.3 to 291.7 g of water/100 g of sample, 5.53 to 7.63, 60.3 to 73.8%, 4.43 to 6.70, and 11 to 150 s. The particle size analysis of the flour samples indicated significant differences (p<0.05). The least gelation concentration of the flour samples ranged from 6 to 14%. The colour of the flours fell between light and saturated, with the exception of cassava, millet and maize flours which appear dark and dull. The properties of food flours depend largely on the inherent property of the food material and may influence their functional behaviour as food materials.

Keywords: Properties, staple food flours, Nigeria, cereals, tuber, root crops, fruits.

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Authors: Tahir Majeed, Michael Handschuh, René Meier

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Rheumatoid Arthritis patients have swelling and pain in joints of the hand. The regions where the patient feels pain also show increased body temperature. Thermal cameras can be used to detect the rise in temperature of the affected regions. To monitor the progression of Rheumatoid Arthritis, patients must visit the clinic regularly for scanning and examination. After scanning and evaluation, the dosage of the medicine is regulated accordingly. To monitor the disease progression over time, the correlation of the images between different visits must be established. It has been observed that the thermal measurements do not remain the same over time, even within a single scanning, when low-cost thermal cameras are used. In some situations, temperatures can vary as much as 2◦C within the same scanning sequence. In this paper, it has been shown that although the absolute temperature varies over time, the relative difference between different regions remains similar. Results have been computed over four scanning sequences and are presented.

Keywords: Relative thermal difference, rheumatoid arthritis, thermal imaging, thermal sensors.

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Authors: Hamid. Gholami, Mohammad. Chamani, Armin. Towhidi, Mohammad. H. Fazeli

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The aim of current study was to investigate the changes in the quality parameters of Holstein bull semen during the heat stress and the effect of feeding a source of omega-3 fatty acids in this period. Samples were obtained from 19 Holstein bulls during the expected time of heat stress in Iran (June to September 2009). Control group (n=10) were fed a standard concentrate feed while treatment group (n=9) had this feed top dressed with 100 g of an omega-3 enriched nutriceutical. Semen quality was assessed on ejaculates collected after 1, 5, 9 and 12 weeks of supplementation. Computer-assisted assessment of sperm motility, viability (eosinnigrosin) and hypo-osmotic swelling test (HOST) were conducted. Heat stress affected sperm quality parameters by week 5 and 9 (p<0.05). Supplementation has significantly increased total motility, progressive motility, HOST and average path velocity in the fresh semen of bulls (P<0.05).

Keywords: Bull, heat stress, omega-3 fatty acids, spermatozoa.

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Authors: Sri Sumartiningsih

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In elevating performance in competetive sports, an athlete must continously train in achieving maximum performance,but needs to pay attention to recovery therapy, that is to recover from fatigue as well as injury.The correct recovery therapy will assist in process of recovery and helps in the training in achieving better performace. Binahong (Anredera cordifolia) was proven empirically by the locals in assisting speedy recovery from an injury.Clinical research with lab animals receiving blunt trauma injury, microscopically shown signs of: 1) redness, 2) heatiness, 3) swelling and, 4) lack of activity. There is also microscopic indication of: 1) infiltration of inflame cells (migration of cells to the trauma area), 2) Cells necrosis, 3) Congestion (as a result of dead red blood cells), 4) uedema. On administration of Binahong for 3 days, there is a significant drop of 5% in cell inflammation, 2% increase of fibroblast (cell membrance) count.Conclutin: Binahong do assist in reducing cell inflammation and increase counts of cells fibroblast. Suggestion: In helping athlete's to recover from force injury, we need study about Binahong's roots to inflammation cell and healing of injuried cell.

Keywords: Binahong, sport injury, hematoma

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Authors: Magdi M. E. Zumrawi, Khalid A. Eltayeb

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Chemical stabilization is a technique commonly used to improve the expansive soil properties. In this regard, an attempt has been made to evaluate the influence of Calcium Chloride (CaCl2) stabilizer on the engineering properties of expansive soil. A series of laboratory experiments including consistency limits, free swell, compaction, and shear strength tests were performed to investigate the effect of CaCl2 additive with various percentages 0%, 2%, 5%, 10% and 15% for improving expansive soil. The results obtained shows that the increase in the percentage of CaCl2decreased the liquid limit and plasticity index leading to significant reduction in the free swell index. This, in turn, increased the maximum dry density and decreased the optimum moisture content which results in greater strength. The unconfined compressive strength of soil stabilized with 5% CaCl2 increased approximately by 50% as compared to virgin soil. It can be concluded that CaCl2 had shown promising influence on the strength and swelling properties of expansive soil, thereby giving an advantage in improving problematic expansive soil.

Keywords: Calcium chloride, chemical stabilization, expansive soil, improving.

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Authors: N. Phattanakulkaewmorie, T. Paseephol, A.Moongngarm

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This study investigated the effect of germination on chemical compositions, physio-chemical properties of malted (germinated) red sorghum flours and evaluated characteristics of gluten free breads from sorghum flour. Results showed that germinated sorghum flour had higher amylase activity, swelling power and solubility at 95°C, but lower in the peak, break down, final and set back viscosities than ungerminated sample (p≤0.05). Five gluten free breads made from sorghum flour blends, with different ratios of ungerminated and germinated sorghum flour, were compared for the physical properties with those made from wheat flour. Crumb hardness, cohesiveness, gumminess and chewiness of sorghum breads were found significantly higher than those of wheat bread. With increasing of ungerminated flour proportion, the bread hardness increased while the cohesiveness declined. Sorghum breads appeared red to human eyes with a*values of 10.41-15.77.Their crust and crumb colors differed significantly from those of wheat bread.

Keywords: Flour, germination, gluten free bread, sorghum.

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Authors: Ahmet E. Osmanlioglu

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In this study, natural bentonite was used as natural clay material and samples were taken from the Kalecik district in Ankara. In this research, bentonite is the subject of an analysis from standpoint of assessing the basic properties of engineered barriers with respect to the buffer material. Bentonite and sand mixtures were prepared for tests. Some of clay minerals give relatively higher hydraulic conductivity and lower swelling pressure. Generally, hydraulic conductivity of these type clays is lower than <10-12 m/s. The hydraulic properties of clay-sand mixtures are evaluated to design engineered barrier specifications. Hydraulic conductivities of bentonite-sand mixture were found in the range of 1.2x10-10 to 9.3x10-10 m/s. Optimum B/S mixture ratio was determined as 35% in terms of hydraulic conductivity and mechanical stability. At the second stage of this study, all samples were compacted into cylindrical shape molds (diameter: 50 mm and length: 120 mm). The strength properties of compacted mixtures were better than the compacted bentonite. In addition, the larger content of the quartz sand in the mixture has the greater thermal conductivity.

Keywords: Bentonite, hydraulic conductivity, clay, nuclear waste disposal.

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Authors: Su-Ling Li, Qun-Yu Gao

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Mung bean starches were subjected to heat-moisture treatment (HMT) by different moisture contents (15%, 20%, 25%, 30% and 35%) at 120Ôäâ for 12h. The impact on the yields of resistant starch (RS), microstructure, physicochemical and functional properties was investigated. Compared to native starch, the RS content of heat-moisture treated starches increased significantly. The RS level of HMT-20 was the highest of all the starches. Birefringence was displayed clear at the center of native starch. For HMT starches, pronounced birefringence was exhibited on the periphery of starch granules; however, birefringence disappeared at the centre of some starch granules. The shape of HMT starches hadn-t been changed and the integrity of starch granules was preserved for all the conditions. Concavity could be observed on HMT starches under scanning electronic microscopy. After HMT, apparent amylose contents were increased and starch macromolecule was degraded in comparison with those of native starch. There was a reduction in swelling power on HMT starches, but the solubility of HMT starches was higher than that of native starch. Both of native and HMT starches showed A-type X-ray diffraction pattern. Furthermore, there is a higher intensity at the peak of 15.0 and 22.9 Å than those of native starch.

Keywords: Resistant starch, mung bean (Phaseolus radiatus) starch, heat-moisture treatment, physicochemical properties.

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Authors: Nagasamy Venkatesh Dhandapani

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The objective of the present study was to develop sustained release oral matrix tablets of anti epileptic drug levetiracetam. The sustained release matrix tablets of levetiracetam were prepared using hydrophilic matrix hydroxypropyl methylcellulose (HPMC) as a release retarding polymer by wet granulation method. Prior to compression, FTIR studies were performed to understand the compatibility between the drug and excipients. The study revealed that there was no chemical interaction between drug and excipients used in the study. The tablets were characterized by physical and chemical parameters and results were found in acceptable limits. In vitro release study was carried out for the tablets using 0.1 N HCl for 2 hours and in phosphate buffer pH 7.4 for remaining time up to 12 hours. The effect of polymer concentration was studied. Different dissolution models were applied to drug release data in order to evaluate release mechanisms and kinetics. The drug release data fit well to zero order kinetics. Drug release mechanism was found as a complex mixture of diffusion, swelling and erosion.

Keywords: Levetiracetam, sustained-release, hydrophilic matrix tablet, HPMC grade K 100 MCR, wet granulation, zero order release kinetics.

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Authors: Yulu Zhang, Atushi Teramoto, Taka-Aki Ohkubo

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In this study, the effect of expansive additives on autogenous shrinkage and delayed expansion of ultra-high strength mortar was explored. The specimens made for the study were composed of ultra-high strength mortar, which was mixed with ettringite-lime composite type expansive additive. Two series of experiments were conducted with the specimens. The experimental results confirmed that the autogenous shrinkage of specimens was effectively decreased by increasing the proportion of the expansive additive. On the other hand, for the specimens, which had 7% expansive additive, and were cured for seven days at a constant temperature of 20°C, and then cured for a long time in either in an underwater, moist (Relative humidity: 100%) or dry air (Relative humidity: 60%) environment, excessively large expansion strain occurred. Specifically, typical turtle shell-like swelling expansion cracks were confirmed in the specimens that underwent long-term curing in an underwater and moist environment. According to the result of hydration analysis, the formation of expansive substances, calcium hydroxide and alumina, ferric oxide, tri-sulfate contribute to the occurrence of delayed expansion.

Keywords: Ultra-high strength mortar, expansive additive, autogenous shrinkage, delayed expansion.

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Authors: Simon Bambang Widjanarko, Novita Wijayanti, Aji Sutrisno

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There is long history of konjac tubers being used as a cure for certain diseases in China and Japan. Konjac flour is prepared from konjac tubers and it contains high concentration of glucomannan. Konjac Glucomannan (KGM) is dietary fiber and the role of which has been demonstrated in weight reduction, lowering blood cholesterol and sugar level, promoting intestinal activity etc. Konjac glucomanan has a property of swelling by absorbing water, more than a hundred times its own weight. Therefore it helps increasing weight of feces, water content of feces, and promotes satiety feeling. Mode of actions of dietary fibre as laxatives agents includes holding water inside the bowel lumen, inhibition of water absorption in the colon and stimulating colonic motility. Number of fecal pellets did not effected in rats were fed on 300 and 600 mg/kg of konjac flour, as well as constipated control and Dulcolax treatment. Water content, weight of fecal pellets and gastrointestinal transit ratio were higher in rats treated with 600 mg/kg than 300 mg/kg of konjac flour. Rats were administered with Dulcolax showed the highest gastrointestinal transit ratio, followed by 600 mg/kg konjac flour. The lowest feed consumption was noted in 600 mg/kg konjac flour diet group.

Keywords: Laxative, konjac flour, Amorphophallus muelleri Blume, glucomannan, constipation.

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Authors: André C. Silva, Débora N. Sousa, Elenice M. S. Silva, Thales P. Fontes, Raphael S. Tomaz

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Starches are widely used as depressant in froth flotation operations in Brazil due to their efficiency, increasing the selectivity in the inverse flotation of quartz depressing iron ore. Starches market have been growing and improving in recent years, leading to better products attending the requirements of the mineral industry. The major source of starch used for iron ore is corn starch, which needs to be gelatinized with sodium hydroxide (NaOH) prior to use. This stage has a direct impact on industrials costs, once the lowest consumption of NaOH in gelatinization provides better control of the pH in the froth flotation and reduces the amount of electrolytes present in the pulp. In order to evaluate the gelatinization degree of different starches and flour were subjected to the addiction of NaOH and temperature variation experiments. Samples of starch (corn, cassava, HIPIX 100, HIPIX 101 and HIPIX 102 commercialized by Ingredion) and flour (cassava and potato) were tested. The starch samples were characterized through Scanning Electronic Microscopy and the amylose content were determined through spectrometry, swelling and solubility tests. The gelatinization was carried out through titration with NaOH, keeping the solution temperature constant at 40 ^oC. At the end of the tests, the optimal amount of NaOH consumed to gelatinize the starch or flour from different botanical sources was established and a correlation between the content of amylopectin in the starch and the starch/NaOH ratio needed for its gelatinization.

Keywords: Froth flotation, gelatinization, sodium hydroxide, starches and flours.

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Authors: Tamer A. Tabet, Fauziah Abdul Aziz, Shahidan Radiman

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The spiral angle of the elementary cellulose fibril in the wood cell wall, often called microfibril angle, (MFA). Microfibril angle in hardwood is one of the key determinants of solid timber performance due to its strong influence on the stiffness, strength, shrinkage, swelling, thermal-dynamics mechanical properties and dimensional stability of wood. Variation of MFA (degree) in the S2 layer of the cell walls among Acacia mangium trees was determined using small-angle X-ray scattering (SAXS). The length and orientation of the microfibrils of the cell walls in the irradiated volume of the thin samples are measured using SAXS and optical microscope for 3D surface measurement. The undetermined parameters in the analysis are the MFA, (M) and the standard deviation (σФ) of the intensity distribution arising from the wandering of the fibril orientation about the mean value. Nine separate pairs of values are determined for nine different values of the angle of the incidence of the X-ray beam relative to the normal to the radial direction in the sample. The results show good agreement. The curve distribution of scattered intensity for the real cell wall structure is compared with that calculated with that assembly of rectangular cells with the same ratio of transverse to radial cell wall length. It is demonstrated that for β = 45°, the peaks in the curve intensity distribution for the real and the rectangular cells coincide. If this peak position is Ф45, then the MFA can be determined from the relation M = tan-1 (tan Ф45 / cos 45°), which is precise for rectangular cells. It was found that 92.93% of the variation of MFA can be attributed to the distance from pith to bark. Here we shall present our results of the MFA in the cell wall with respect to its shape, structure and the distance from pith to park as an important fast check and yet accurate towards the quality of wood, its uses and application.

Keywords: Small-Angle X-Ray Scattering, Microfibril Angle, MFA, rectangular cell wall and real cell wall, Acacia mangium.

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Authors: H. Ferfera-Harrar, T. Benhalima, D. Lerari

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Contamination of water, due to the discharge of untreated industrial wastewaters into the ecosystem, has become a serious problem for many countries. In this study, bioadsorbents based on chitosan-g-poly(acrylamide) and montmorillonite (MMt) clay (CTS-g-PAAm/MMt) hydrogel nanocomposites were prepared via free‐radical grafting copolymerization and crosslinking of acrylamide monomer (AAm) onto natural polysaccharide chitosan (CTS) as backbone, in presence of various contents of MMt clay as nanofiller. Then, they were hydrolyzed to obtain highly functionalized pH‐sensitive nanomaterials with uppermost swelling properties. Their structure characterization was conducted by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses. The adsorption performances of the developed nanohybrids were examined for removal of methylene blue (MB) cationic dye from aqueous solutions. The factors affecting the removal of MB, such as clay content, pH medium, adsorbent dose, initial dye concentration and temperature were explored. The adsorption process was found to be highly pH dependent. From adsorption kinetic results, the prepared adsorbents showed remarkable adsorption capacity and fast adsorption rate, mainly more than 88% of MB removal efficiency was reached after 50 min in 200 mg L^-1 of dye solution. In addition, the incorporating of various content of clay has enhanced adsorption capacity of CTS-g-PAAm matrix from 1685 to a highest value of 1749 mg g^-1 for the optimized nanocomposite containing 2 wt.% of MMt. The experimental kinetic data were well described by the pseudo-second-order model, while the equilibrium data were represented perfectly by Langmuir isotherm model. The maximum Langmuir equilibrium adsorption capacity (q_m) was found to increase from 2173 mg g⁻¹ until 2221 mg g⁻¹ by adding 2 wt.% of clay nanofiller. Thermodynamic parameters revealed the spontaneous and endothermic nature of the process. In addition, the reusability study revealed that these bioadsorbents could be well regenerated with desorption efficiency overhead 87% and without any obvious decrease of removal efficiency as compared to starting ones even after four consecutive adsorption/desorption cycles, which exceeded 64%. These results suggest that the optimized nanocomposites are promising as low cost bioadsorbents.

Keywords: Chitosan, clay, dye adsorption, hydrogels nanocomposites.

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Authors: W. V. W. H. Wickramaarachchi, S. Walpalage, S. M. Egodage

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Thermoplastic elastomer (TPE) is a multifunctional polymeric material which possesses a combination of excellent properties of parent materials. Basically, TPE has a rubber phase and a thermoplastic phase which gives processability as thermoplastics. When the rubber phase is partially or fully crosslinked in the thermoplastic matrix, TPE is called as thermoplastic elastomer vulcanizate (TPV). If the rubber phase is non-crosslinked, it is called as thermoplastic elastomer olefin (TPO). Nowadays TPEs are introduced into the commercial market with different products. However, the application of TPE as a roofing material is limited. Out of the commercially available roofing products from different materials, only single ply roofing membranes and plastic roofing sheets are produced from rubbers and plastics. Natural rubber (NR) and high density polyethylene (HDPE) are used in various industrial applications individually with some drawbacks. Therefore, this study was focused to develop both TPO and TPV blends from NR and HDPE at different compositions and then to identify the best blend composition to use as a roofing material. A series of blends by varying NR loading from 10 wt% to 50 wt%, at 10 wt% intervals, were prepared using a twin screw extruder. Dicumyl peroxide was used as a crosslinker for TPV. The standard properties for a roofing material like tensile properties tear strength, hardness, impact strength, water absorption, swell/gel analysis and thermal characteristics of the blends were investigated. Change of tensile strength after exposing to UV radiation was also studied. Tensile strength, hardness, tear strength, melting temperature and gel content of TPVs show higher values compared to TPOs at every loading studied, while water absorption and swelling index show lower values, suggesting TPVs are more suitable than TPOs for roofing applications. Most of the optimum properties were shown at 10/90 (NR/HDPE) composition. However, high impact strength and gel content were shown at 20/80 (NR/HDPE) composition. Impact strength, as being an energy absorbing property, is the most important for a roofing material in order to resist impact loads. Therefore, 20/80 (NR/HDPE) is identified as the best blend composition. UV resistance and other properties required for a roofing material could be achieved by incorporating suitable additives to TPVs.

Keywords: Thermoplastic elastomer, natural rubber, high density polyethylene, roofing material.

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