Affect Water Absorption Research Articles

The effect of alkaline–silane treatment of rubberwood flour for water absorption and mechanical properties of plastic composites

Rubberwood flour (RWF) was treated by alkaline, silane, and alkaline–silane, and consequently, reinforced recycled polypropylene (rPP) composites. The wood–plastic composites (WPCs) were prepared with 40 wt% RWF content using a twin-screw extruder, followed by compression molding. Silane treatment was applied at various concentrations and treatment times to evaluate the effect of treatment conditions on water absorption, mechanical properties, thermal properties, and morphological characterization of WPCs. The results indicated that alkaline–silane treatment of RWF exhibits higher properties in comparison to silane or alkaline only. In addition, silane concentrations significantly affected water absorption, mechanical strength, and hardness, while treatment times remained relatively unaffected by these properties. The best water resistance, mechanical strength, and hardness of WPCs were achieved by alkaline–silane treatment with 5% silane concentration for 2 h, which improved the interfacial adhesion of RWF and rPP as well as increased the crystallinity in the WPCs.

<b>Germination and biochemical components of <i>Salvia hispanica</i> L. seeds at different salinity levels and temperatures

Most plant species are susceptible to the effects of salinity, such as increases in osmotic potentials and deleterious ionic effects, which in turn affect water absorption in plants and, consequently, compromise germination and seedling growth. Hence, this study aimed to evaluate the effects of salinity on the germination, initial growth, and physiological and biochemical components of S. hispanica seedlings at different temperatures. The experimental design was completely randomized, with treatments distributed in a 5 x 4 factorial scheme with five saline concentrations (0.0 (control), 4.5, 9.0, 13.5, and 18.0 dS m -1 ) four temperature regimes (20, 25, 30, and 20-30°C), and four replicates of 50 seeds per treatment. The experiment evaluated the germination, growth, biochemical components (chlorophyll a , chlorophyll b , total carotenoids, amino acids, proline and sugars) and phytomass accumulation of S. hispanica seedlings. Saline levels higher than 4.5 dS m -1 together with treatment temperatures of 30 or 20-30°C negatively affected the germination, vigor, growth and biochemical components of the seedlings. The 25°C treatment temperature promoted the best conditions for the development of S. hispanica seedlings up to the saline level of 9.0 dS m -1 .

Effect of Barium Carbonate Addition on the Properties of Porcelain Ceramic Tile

In this study, six different recipes (0%, 2-10 wt.% with barium carbonate) of porcelain tile were fabricated using the firing temperature of 1210 °C. The effects of barium carbonate as a secondary flux material on the linear shrinkage, bulk density and water absorption properties of ceramics were investigated. Microstructure and chemical analysis of ceramics were examined using SEM and XRD analysis instruments, respectively. Addition of barium carbonate between 2-6 wt.% on the ceramics did not affect water absorption value (zero) which was recommended for porcelain tiles. However this was found to dramatically increase up to 6.65% after addition of 8 wt.% and 10 wt.% barium carbonate.

WATER PERMEABILITY OF EXTERIOR WOOD COATINGS: WATERBORNE ACRYLATE DISPERSIONS FOR WINDOWS

Permeability of coatings for water and water vapor is an important factor in their wood protective function. In this study, the permeability of coatings in terms of liquid water and water vapor absorption and desorption was measured based on different parts of the standard EN 927. This study evaluated the permeability of commercial coating systems and ascertained effects of coating layering on the coating permeability. For this measurement, six different waterborne acrylate dispersions were used as paint on spruce test samples. The results clearly revealed that liquid water and water vapor uptake were affected by coating film thickness, number of coats, and coating composition (producer). It was ascertained that the type of coating pigmentation affected water absorption of coatings and that with a constant coating film thickness, the number of coats affected water vapor absorption and desorption, but not water absorption. Furthermore, it was observed that the number of coats affected the correlation between the coating film thickness and water vapor absorption and desorption. The values for water vapor absorption were much higher than for liquid water absorption and, unlike the water vapor absorption rate, the water vapor desorption rate was approximately 50% lower.

Current knowledge of ghrelin in amphibians.

We are exploring physiological importance of the ghrelin system in vertebrates. This review summarizes current knowledge of the ghrelin system in amphibians. Our study on ghrelin precursor in various amphibians revealed that the third amino acid with acyl modification has changed to threonine (Thr-3) instead of serine (Ser-3) only in the genus, Rana. Functional analyses of the ghrelin receptor in three species of amphibians, Japanese fire belly newt, American bullfrog and Japanese tree frog revealed that ghrelin and GHS-R1a agonists increase intracellular Ca2+ concentration in HEK293 cells expressing each receptor, and that ligand selectivity of ghrelin with Ser-3 and Thr-3 that expected to see in the bullfrog receptor was not found in the two frog receptors, but in the newt receptor. The brain, gastrointestinal tract, kidney and gonad highly express GHS-R1a mRNA. In frogs and newt, fasting did not increase GHS-R1a mRNA expression in the brain, but in the stomach. However, intraperitoneal (IP) injection of ghrelin did not affect food intake. A dehydration treatment increased GHS-R1a mRNA expression in the brain, stomach and ventral skin in the tree frog. However, intracerebroventricular (ICV) injection of ghrelin did not affect water absorption. Ghrelin did not influence gastrointestinal motility in in vitro studies using smooth muscle strips of the bullfrog and newt in vitro. These results suggest that the ghrelin system is present in various amphibians, but little is known about the physiological functions except hypophyseal hormone secretion.

Analysis of Various Media Concrete Penetrating Ability Depending on Different Factors Affecting Water Absorption

The problem of influence of the technological concreting joint and its defects on the functioning of reinforced concrete structures has been studied. The normative requirements on the structure of a functional concreting joint and the existing proposals for improving adhesion of the "new" and "old" concretes have been considered. The results of the experimental study of the influence of the type and the pH level of the medium on its concrete penetration ability e, as well as the impact of such technological factors as orientation of layers of the "old" concrete in relation to the location of the water absorbing surface and the surface state (preliminary stripping the cement film of the contact area of the concrete surface) on water absorption (moisture saturation) of the concrete, and the study of kinetics of water absorption of concrete are presented here. The conclusions that serve as a basis for drawing up flow charts for organization of the functional joint of concrete structures, have been formulated.

Influence of lignin source and esterification on properties of lignin-polyethylene blends

Lignins from pulp mills and biorefineries will gain increasing commercial importance in the next years. Their utilisation in polyolefin blends is of growing research interest as it offers a value-added usage of lignin as well as substitution of non-renewable resources. However, the low compatibility of lignin and polyolefins restrains a satisfying blend production and leads to poor mechanical properties. This can be overcome by modifying lignin prior to its incorporation into polymers in order to reduce its polarity. In this study, five lignins from different raw material sources and production processes were esterified with acetic, propionic and butyric anhydride and subsequently mixed with polyethylene with a weight ratio of 1:1. The paper provides a comprehensive and systematic evaluation of the influence of esterification as well as chemical composition of lignins on mechanical properties and, for the first time, water absorption of lignin-polyethylene blends. Properties of blends were found to improve upon lignin esterification. Compared to blends with unmodified lignin, a progressive increase of tensile (+45%) and flexural (+30%) strength could be observed with increasing length of the ester carbon chain. Lignin source and chemical composition affect water absorption of blends, but show no significant effect on mechanical properties as similar values were observed for blends produced with the respective lignin esters.

Nanostructured superhydrophobic lyocell fabrics with asymmetric moisture absorbency: Moisture managing properties

This study investigated moisture management properties of a single-faced superhydrophobic fabric. A single-faced superhydrophobic lyocell fabric, where one face of the surface is superhydrophobic and the opposite face is hydrophilic, was produced by a two-step plasma process on one side of the fabric: (1) the addition of nano-scale roughness by 5 minutes of O2 plasma etching; (2) subsequent 30 seconds of plasma enhanced chemical vapor deposition with hexamethyldisiloxane to lower the surface energy of lyocell fibers. As a result, the superhydrophobic lyocell fabric exhibited water repellency with a static water contact angle greater than 161° on the treated surface, allowing water absorption from the untreated face. The nanometer depth of the superhydrophobic layer in the hydrophilic textile affected water absorption capacity, drying rate, vertical wicking rate, and moisture management properties. The air permeability and water vapor transmission rate of the superhydrophobic treated lyocell fabric were hardly changed. The superhydrophobic properties were maintained after a gentle wash cycle, although the level of superhydrophobicity was reduced, especially when it was washed with detergent. This superhydrophobic and moisture managing textile would be relevant for an application that requires a water repellent property on one face and water absorbing property on the opposite face, such as medical operation gowns, wound dressings, and hygienic products.

Effect of the anatomical point of hanging and dripping time on water retention of chicken carcasses

Pre-cooling in water tanks (pre-chiller and chiller) is an important step in preserving the quality of chicken meat. After pre-cooling, the carcasses are hung by the wing and neck for 5 min to allow excess water to drain. The weight of the carcasses is monitored before and after pre-cooling to ensure that weight gain due to water absorption does not exceed 8%. However, no information is available as to how hanging the carcass from other anatomical points might affect water retention of carcasses and water loss during dripping. The present study evaluated the effects of the anatomical point of hanging and hanging time on water retention of carcasses and water loss during dripping. One hundred and sixteen carcasses (mean weight 1,662 ± 13 g) were chilled by cold-water immersion systems in 2 steps (pre-chilling and chilling). The results showed that after chilling, the carcasses needed at least 3 min of dripping time (p < 0.05) to maintain water absorption below 8% of the final weight, and that the point of hanging did not affect water absorption (p > 0.05). Data in this study clearly indicate that leg hanging is a practical alternative, and 5 min of dripping time is needed to maintain water absorption within the desired limit.

Effect of mechanically damaged starch from wheat flour on the quality of frozen dough and steamed bread

The influence of damaged starch (DS) on the quality of frozen dough and steamed bread were investigated. Characterization of the farinographical properties showed that DS levels affected water absorption, development, weakness, falling number and gluten index. Flour viscosity profiles indicated that pasting temperatures increased, but peak viscosity, low viscosity, breakdown, final viscosity and setback increased and then decreased with increasing amounts of DS. Compared to leavened dough, unleavened dough had significantly higher peak times, of T21 and T22, and was also affected by DS concentration. Steamed bread had a higher specific volume, relatively lower hardness, exhibited more whiteness, and a higher degree of gumminess and chewiness with higher DS levels. We compared two methods of making steamed bread and assessed the quality of the product. We found that an appropriate DS content improved the quality of frozen dough and steamed bread. This study provides the basis for future development and improvements to methods for making frozen dough products.

Hydrocolloids가 쌀을 첨가한 빵용 밀가루 반죽의 물성학적 특성에 미치는 영향

ABSTRACT This study was carried out to investigate the effect of hydrocolloids [hydroxypropylmethyl cellulose (HPMC), xanthan gum (XG), guar gum (GG), and glucomannan (GM)] on the physicochemical properties of bread flour dough containing rice flour. In amylograph analysis, the significantly lowest gelatinization temperature was ob-tained in dough with XG ( P <0.05). XG revealed the highest maximum viscosity while GM revealed the lowest. In viscograph test, the lowest gelatinization temperature and maximum viscosity showed the same result as in the amylograph. Breakdown value was also highest in dough containing XG, but lowest in the control and dough containing HPMC. Setback value was highest in dough containing HPMC, but lowest in dough containing XG. In farinograph analysis, consistency was greatest in dough with HPMC and XG. Hydrocolloids affected water absorption, which was highest in dough containing GM. Development times of dough containing HPMC and XG were low. Stability was lowest in dough with XG. Degree of softening was reduced in dough containing HPMC and GG compared to the control but increased in dough containing XG and GM. Dough containing HPMC and GG showed the largest volume at 3 h of fermentation. Dough with HPMC showed the lowest pH value. Hydrocolloids in this study affected physicochemical properties of dough.

Bread Supplementation with Hemp Seed Cake: A By‐Product of Hemp Oil Processing

AbstractHemp seed cake remaining after oil pressing was processed in the laboratory conditions to obtain hemp flour that influence the rheological properties of wheat dough, and the quality of bread was studied. The obtained hemp flour was mixed with wheat flour at different hemp/wheat flour ratios (0/100, 5/95, 10/90 and 20/80). The obtained results indicated that hemp flour affected water absorption and dough development time, and consequently bread volume, color and structural and textural properties of bread crumb regardless of the level of substitution. However, the presence of hemp flour in formulation, as being nongluten flour, did not necessarily distort all rheological properties. In this context, dough stability and dough strength were not significantly affected by the addition of hemp flour up to 10%, whereas substitution level of 20% resulted in the decrease (P &lt; 0.05) of these parameters. Bread supplemented with hemp flour had higher nutritional value and provided elevated intake of important nutrients such as proteins and macro‐ and microelements, especially iron.Practical ApplicationsRecent scientific research indicated that hemp seed is a source of valuable nutrients, so it is recognized as one of nature's perfect balanced foods. In order to fulfill the requirements of sustainable food processing, the reutilization of food waste is a common issue especially due to the fact that food waste is rich in proteins, dietary fibers, antioxidants, colorants and other nutrients. In that sense, oilseed meals that remain after oil cold pressing have been recognized as one of the most valuable sources of proteins. One of the promising but not widely investigated cold‐pressed seed meals is that which remains after cold pressing of hemp seeds known as hemp flour. Obtained results showed that the breads supplemented with hemp flour had higher nutritional value providing elevated intake of important nutrients such as proteins and macro‐ and microelements, especially iron, while reducing the metabolizable energy from carbohydrates.

Physical and mechanical properties of randomly oriented coir fiber–cementitious composites

In this study; important mechanical and physical properties of cement composites prepared with fine aggregate and coir fibers were investigated. In addition to control mortar mixtures without fiber addition, coir fiber incorporated composites were prepared by adding 0.4%, 0.6% and 0.75% coir fiber by weight of total mixtures, respectively. The effect of coir fibers on the mechanical properties of composites under compressive and flexural loads, water absorption capacity and thermal conductivity of mortars were investigated. Moreover, similar mixtures were prepared with alkali treated coir fibers having same ratios and the findings were discussed. As a result, fiber incorporation affects water absorption capacity of mortars, enhances their mechanical and thermal properties and decreases their unit weight. These effects become more significant by increasing amount of fibers and when alkali treated coir fibers are replaced with untreated ones.

Optimizing the formulation of polypropylene and rubberwood flour composites for moisture resistance by mixture design

D-optimal mixture experimental design was used to determine the optimal mixture of composites from rubberwood ( Hevea brasiliensis) flour and recycled polypropylene and to systematically analyze the effects of composition, namely recycled polypropylene, rubberwood flour, maleic anhydride-grafted polypropylene, and ultraviolet stabilizer fractions. Panel samples were extruded, and their properties were characterized. The overall compositions significantly affected water absorption, thickness swelling, flexural strength and modulus, and maximum strain. Water absorption and thickness swelling increased with the fraction of rubberwood flour. At long immersion times, flexural strength and modulus decreased, but maximum strain increased with high fraction of rubberwood flour. The fraction of maleic anhydride-grafted polypropylene only slightly affected water absorption and flexural properties, while the ultraviolet stabilizer fraction had a clear negative effect increasing water absorption and decreasing flexural properties. The models fitted were used for optimization of a desirability score, substituting for the multiple objectives modeled. The optimal formulation found was 68.9 wt% recycled polypropylene, 25.0 wt% rubberwood flour, 5.0 wt% maleic anhydride-grafted polypropylene, 0.1 wt% ultraviolet stabilizer, and 1.0 wt% lubricant. This formulation of the composites can be used for most suitable applications based on the moisture resistance.

Quantitative Fractal Evaluation of Herbicide Effects on the Water‐Absorbing Capacity of Superabsorbent Polymers

The water absorption capacity of superabsorbent polymers (SAPs) is important for agricultural drought resistance. However, herbicides may leach into the soil and affect water absorption by damaging the SAP three‐dimensional membrane structures. We used 100‐mesh sieves, electron microscopy, and fractal theory to study swelling and water absorption in SAPs in the presence of three common herbicides (atrazine, alachlor, and tribenuron‐methyl) at concentrations of 0.5, 1.0, and 2.0 mg/L. In the sieve experiments it was found that 2.0 mg/L atrazine reduces the capacity by 9.64–23.3% at different swelling points; no significant diminution was observed for the other herbicides or for lower atrazine concentrations. We found that the hydrogel membrane pore distributions have fractal characteristics in both deionized water and atrazine solution. The 2.0 mg/L atrazine destroyed the water‐retaining polymer membrane pores and reduced the water‐absorbing mass by modifying its three‐dimensional membrane structure. A linear correlation was observed between the fractal analysis and the water‐absorbing mass. Multifractal analysis characterized the membrane pore distribution by using the range of singularity indexes Δα (relative distinguishing range of 16.54–23.44%), which is superior to single‐fractal analysis that uses the fractal dimension D (relative distinguishing range of 2.5–4.0%).

Structure and properties of corn stalk-composite superabsorbent

A novel corn stalk-composite superabsorbent was prepared by graft copolymerization of corn stalk with acrylic acid, acrylamide and sodium 4-styrenesulfonate in aqueous solutions after the pretreatment of corn stalk, using N,N-methylenebisacrylamide as a crosslinker and ammonium persulfate and sodium bisulfite as redox initiators. Factors affecting water absorption rate of the superabsorbent composite, such as the amount of corn stalk, crosslinker, and initiator were investigated. Adsorption rates of Ni(II) and Cd(II) ions of the corn stalk-composite superabsorbent were also studied. Corn stalk-composite superabsorbent had equilibrium adsorption capacities of 210 mg g−1 within 50 min and 505 mg g−1 within 150 min for Ni(II) and Cd(II) ions, respectively. Fourier transform infrared spectroscopy indicated the structure of corn stalk-composite superabsorbent. X-ray diffraction indicated that the sharp diffraction peaks of corn stalks disappeared and transformed into a large and wide amorphous dispersion peak. The discontinuous sheet structure of corn stalks disappeared and gel aggregates with microporous holes and small capillary pores were formed after corn stalk graft modification. After absorbing water, the swollen composite superabsorbent formed a network-like structure filled with water. Thermal gravimetric analysis indicated that the composite superabsorbent had high thermal stability with three step degradations.

Hydrophobic properties conferred to Kraft pulp by a laccase-catalysed treatment with lauryl gallate

Hydrophobic properties were conferred to a high-lignin-content Kraft pulp by a laccase-catalysed treatment in the presence of lauryl gallate (LG). The treatment resulted in a two-fold increase in contact angle and conferred water absorption resistance to the pulp. Kappa number was increased, indicating that some phenolic compounds were incorporated in the pulp. A control treatment with LG alone did not affect water absorption, demonstrating that laccase was essential to attain these new properties. The loss of hydrophobicity after an acetone Soxhlet extraction highlighted that adsorbed acetone-soluble compounds played a key role in the properties. GC-FID and HPSEC-UV analysis of the acetone extract indicated the formation of dodecanol and different phenolic oligomers. SEM images showed the treatment-induced changes in the fibre network. Additional experiments with various reaction times and reactant concentrations highlighted the role of LG oxidation products in the introduction of absorption resistance.

Water Absorption and Tensile Strength of Coconut Filter Fibers/Polypropylene Composites

In this study, we evaluated water absorption and tensile properties of coconut filter fiber reinforced polypropylene composites. The fibers were subjected to various immersion times for 0.5, 1, and 3 h in 0.5 % acrylic acid solution at room temperature and 0.5 h at 70 oC. The treated fibers were used as reinforcement of polypropylene composites. Water absorption of treated fiber composites was lower than those of untreated fiber composite. Boiling in water significantly affect water absorption rate of the composites. The tensile strength and elastic modulus of treated fiber are higher than untreated fiber. They show a decrease in tendency when the immersion time increased. Tensile strength and elastic modulus of composites with AA-treated at 70 oC fiber are the highest.

Physicochemical properties of extruded germinated wheat and barley as modified by CO2 injection and difference extrusion conditions

SummaryGerminated wheat and barley were extruded with a pilot‐scale corotating twin‐screw extruder under different barrel temperatures (100 and 120 °C), feed moisture content (30 and 35%) and CO2 injection. The effect of germination, barrel temperature, feed moisture content and CO2 injection on physical properties, proximate composition, γ‐aminobutyric acid, β‐glucan, phytic acid and protease activity was investigated. Results indicated that the barrel temperature, moisture content and CO2 injection significantly affected water absorption index (WAI), water‐soluble solid index (WSI), specific length, expansion ratio, bulk density, mechanical properties and colour of all extruded products (P &lt; 0.05). Extrusion process significantly decreased γ‐aminobutyric acid and protease activity in extruded germinated wheat (EGW) and barley (EGB) products (with and without CO2 injection). However, extrusion process (with and without CO2 injection) increased β‐glucan in EGB and decreased phytic acid in EGW. The content of proximate composition, γ‐aminobutyric acid, β‐glucan, phytic acid and protease activity was slightly affected by CO2 injection.

Day‐length effects on protein localisation affect water absorption in barley (Hordeum vulgare) grains

Hordeins are major storage proteins of barley (Hordeum vulgare L.) grains and are considered to influence malting and brewing by forming a matrix surrounding the starch granules which affects the release of fermentable sugars. However, the extent to which environmental factors affect hordein location, and the impact of this on malting performance, have not so far been studied. Therefore the relationship of hordein location to water uptake and malting quality were studied by growing barley cv. Barke under different daylengths (14 h and 18 h of light) in controlled environment conditions. Differences in the locations of hordein storage proteins were observed, with C hordein being located more deeply within the endosperm of both developing grains at 35 days after anthesis and in mature grains under long-day conditions. This deeper location of C hordein was correlated positively with water uptake during the steeping phase of malting. An effect of environment (daylength) on the localisation of C hordein was demonstrated. This difference in hordein localisation was also associated with differences in malting quality with water uptake in the steeping phase being associated positively with the deeper location of C hordein. These results indicate that environmental effects on protein location may affect malting performance of barley grains.