Water Absorption Velocity Research Articles

Evolution law of ultrasonic characteristics and its relationship with coal-measure sandstone mechanical properties during saturation and desaturation

Underground buildings are easily destabilised by water and there is a strong link between their mechanical properties and ultrasonic characteristics. To grasp the above features and the relationship among them, the mechanism of sandstone degradation under water erosion was briefly reviewed. Using the coal-measure sandstone as the object, experimental studies on the dynamic evolution of water content, ultrasonic wave velocity, waveform, uniaxial compressive strength (UCS), elastic modulus (E), and damage mode during saturation-desaturation were carried out. The findings demonstrate that coal-measure sandstones usually exhibit more mechanical parameter deterioration following saturation than non-coal-measure sandstones. During saturation, the water absorption velocity slows down; the P-wave velocity (VP) first fluctuates down, then fluctuates up and finally decreases slightly (VP increases after saturation), and the wave velocity anisotropy coefficient (δi) decreases; the waveform shows a trend of unequal time and unequal amplitude → equal time and equal amplitude → unequal time and equal amplitude, and the first wave reaches a progressively shorter time. During desaturation, the dehydration rate slows down, VP first drops rapidly and then fluctuates slightly and rises slightly near drying (VP decreases after desaturation), δi increases, and the waveform changes in the opposite trend to saturation. Saturation treatment significantly weakened the mechanical properties, while desaturation restored some of the strength lost due to immersion. The sandstone mechanical properties and ultrasonic features are more closely related during saturation than desaturation.

Prediction Method of Water Absorption of Soft Rock Considering the Influence of Composition, Porosity, and Solute Quantitatively

The study of water absorption of soft rock is of great significance to the prevention engineering disasters. However, the research on the prediction method of water absorption of soft rock considering the influence of composition, porosity, and solute is insufficient. Aiming to solve the above problem, water absorption tests are carried out by synthesizing soft rocks and water solutions. Then, the prediction model of water absorption of soft rock is established through quantitative analysis of water absorption data and compared with the water absorption characteristics of natural rock to verify the reliability of the model. The results show that the changes in water content and water absorption velocity of soft rock with time obey the second-order exponential attenuation function and the linear function (double logarithmic coordinates axis), respectively. The types of cations and anions and the type and content of clay minerals have the greatest influence on the process of rock water absorption. In addition, the water absorption prediction model could better predict the water absorption process of natural rock. The research results solve the problem of insufficient research on the soft rock water absorption prediction method considering the influence of composition, porosity and solute.

Evaluation of Aluminium Production Waste in Building Material Production

Purpose The production of aluminum is based on obtaining alumina from bauxite, which is also known as the "Bayer Process." However, waste that is enough to endanger the environment is released at the end of this process applied to obtain aluminum. In Turkey, red mud waste is released from Seydişehir ETİ Aluminum production facilities into the pond located within the settlements. Red mud, which creates a potential environmental problem, should be systematically eliminated. In the literature, there are hundreds of studies on this subject. However, it is observed that these studies will not accelerate the waste consumption process. The consumption of the waste as soon as possible will be possible by using it as the main raw material. In this context, using both the literature and the doctorate study of the manuscript's author, the methods for using the waste as a building material were discussed for the systematic consumption of it. Design/Methodology/Approach Accordingly, in the study, the physical (specific gravity, plastic limit, differential thermal analysis, etc.) and chemical properties (XRF) of the waste red mud were discussed together with the waste generation process starting with the Bayer process. Furthermore, the physical (specific gravity, water absorption, water vapor permeability, initial water absorption velocity), mechanical (compressive strength) of the building materials that could be produced by using the waste were also included in the study. Findings It was concluded that it was possible to produce a quality building material by using the waste as a raw material. Research Limitations/Implications Type the research limitations/implications of the paper here. The study was limited to the mixing of red mud waste and pyroclastic rocks in certain proportions and their use as raw materials in the production of baked building materials by baking at different temperatures. Social/Practical Implications In this study, a solution method to a potential environmental problem was developed. Furthermore, a source of raw material was provided in sustainable building material production. Accordingly, a contribution can be made to the national economy with the building material that can be produced with local opportunities. Originality/Value With the materials and joining methods used in the study, a production was made on a unique subject.

Experimental characterisation of non-encapsulated bio-based concrete with self-healing capacity

The main reason for early corrosion in Reinforced Concrete (RC) structures is crack formation within the concrete cover. Cracks can lead to leakage problems, allowing chloride, oxygen, water and other aggressive chemicals to enter into concrete and eventually causes corrosion of steel reinforcement. The paper shows some results of a novel bio concrete with biological self-healing agent, which added into the concrete mixture, autonomously and actively, inhibits the concrete cracks and potential premature reinforcement corrosion. Two compositions of concrete samples were prepared and casted – CEMI and CEMIII with 60% of Ground Granulated Blast Furnace Slag (GGBS) with and without non-encapsulated bio-product utilising iron respiring bacteria. The developed bio-mineral is capable of sealing cracks and blocking pores resulting in a delay of water-born ions in RC structures, acting as a diffusion barrier of oxygen to protect steel reinforcement's passivity towards corrosion. The fresh test results show that these concretes have the potential to be used in RC heavily reinforced and manually compacted sections with vibrations. The water absorption velocity has been significantly reduced with the inclusion of bio-agent in CEMI and CEMIII concretes samples, which was associated with pores sealing. Maximum water absorption via capillary tends to reduce at least 25% when bio-agent was introduced to concrete type CEMIII. Other results emphases the efficiency of the bio-product in CEMIII medium. The bio-agent does not decrease the compressive strength of tested concretes either for CEMI and CEM III. SEM observation shows that the crystals were well developed near the surface of the crack.

Compression properties of pile fabrics in the presence of water

The compression properties of towel pile fabrics with water contents from 0% to 500% were measured to investigate the effect of pile ratio and weft yarn density. The compression energy decreased substantially from 0% to 50% and 100%, and then increased with the water content. Towel fabric with a high pile ratio showed a larger increase in compression energy than towel fabric with a low pile ratio. Water transfer through the towels was investigated in both horizontal and vertical directions. The vertical water transfer from the pile surface to the base was related to the maximum water absorption velocity ( Vmax). Subjectively evaluated, soft towels showed larger Vmax and compression energy values with water than short-pile towels.

Effect of ultrasonic treatment on the hydration and physicochemical properties of brewing rice

In this study, the influence of ultrasonic treatment on the hydration and physicochemical properties of rice was investigated. We found that the water absorption velocity of rice was increased obviously accompanied with the raising of ultrasonic power. Low-field nuclear magnetic resonance (LF-NMR) demonstrated that the mobility of water protons in rice was influenced by ultrasonic treatment, and scanning electron microscope (SEM) micrographs of the rice showed the loosening of matrix and the formation of microspores on rice surface, which may lead to accelerated hydration and decreased hardness. X-ray diffraction revealed that ultrasonic treatment didn't alter the crystalline pattern of rice, but slightly decreased the relative crystallinity. Furthermore, we found that the rice treated with ultrasonic had higher water binding capability, shorter cooking time and better gelatinization degree than untreated one. Our study indicates that ultrasonic treatment is benefit for shortening the soaking and boiling time of rice in Chinese rice wine brewing process.

Biometric Characterization, Water Absorption Curve and Vigor on Araçá-Boi Seeds

Araçà-boi is a fruit, which awakes great interest for presenting pulp of quality. Their seeds are recalcitrant and present a relatively short period of viability. The water absorption by seeds is a mechanism of growth resuming of the embryo with a subsequent of the tegument breakage by the radical. The seed electric conductivity is a vigor testing is directly related to the membrane permeability. Study of the curve of water absorption by the araçá-boi seeds will contribute to characterize their germination process. In this context, studies concerned with seeds were conducted, which characterized the mass, biometrics, water content, electric conductivity and water imbibition by seeds. It was found that the population of plants established in Manaus-AM produces small, medium and large seeds and which present 70.2, 68.2 and 47.5% of moisture. The greatest water increase takes place in the first hour of absorption, regardless of the size of seeds and water absorption velocity is not influenced by their size. The imbibition curves characterized in the 144-hour period, independent of the size of seeds, show changes of two physiological phases. Both the large and medium seeds present smaller conductivity values, obtaining smaller percentages of germination for possessing increased vigor indices.

Determinación de constantes de velocidad de rehidratación y cambios sobre algunas propiedades físicas en semillas de arveja (Pisum sativum L.)

Introduccion. La rehidratacion por inmersion en agua es una operacion compleja que pretende reconstituir productos; sin embargo, aun son escasas las investigaciones referentes a caracteristicas fisicas dependientes de la humedad en semillas de arveja. La investigacion se ha enfocado en la obtencion de nuevos materiales, uso de tutores y manejo del cultivo. Objetivo. Determinar el efecto de la temperatura sobre las constantes de velocidad de rehidratacion (absorcion de agua) y el efecto de la humedad ganada sobre algunas propiedades fisicas en semillas de arveja (Pisum sativum L.), variedad San Isidro. Materiales y metodos. La rehidratacion se realizo a tres temperaturas (6, 18 y 30°C), empleando una relacion semillas/agua 1:4 (p/v); se tomaron mediciones a 0, 3, 6, 9, 12 y 24 horas. Se utilizo un diseno experimental unifactorial completamente aleatorizado con diez repeticiones, mediante el cual se estudio la influencia de la temperatura sobre las constantes de velocidad de absorcion de agua y la ganancia de humedad sobre algunas propiedades fisicas (peso de mil semillas, esfericidad, densidad real, densidad aparente y porosidad). Resultados. Las constantes de velocidad de absorcion de agua de cada temperatura fueron: 6 °C (2,308*10-3 min-1),18°C (2,511*10-3 min-1) y 30°C (4,154*10-3 min-1); la ganancia de humedad ocasiono aumentos en peso de mil semillas y porosidad, mientras que la esfericidad y densidad real y aparente disminuyen. Conclusion. La temperatura y la humedad presentan efecto significativo sobre la velocidad de rehidratacion y las propiedades fisicas estudiadas.

The Comfort Properties of the Terry Towels Made of Cotton and Polypropylene Yarns

Studies of woven fabric comfort properties have aroused the interest of researchers in recent years. Although studies on the structures of woven terry fabrics are rather limited, the study of the comfort properties these fabrics will reveal new approaches regarding the subject. The terry-structured fabrics, used in bathroom, pool, sea, sauna and Turkish bath, hold an important place in people's personal lives as end-products. The methods of identifying and improving the comfort properties of the terry-woven fabric structure are discussed in this study. In the process of sample production, the towels were made on a loom and standard finishing techniques were applied. Cotton and polypropylene yarns were used in this study, and the properties of woven towel fabrics with alternative weaving constructions were measured and analyzed. The comfort parameters of the gray and finished fabrics such as air-permeability, velocity of water absorption, and vapor permeability were measured under standard laboratory conditions and the obtained data were evaluated statistically. At the end of the experimental studies, the data from the terry fabrics which were made of different yarns and different structures were evaluated in order to identify the fabric and yarn parameters which will lead to the best comfort. The experimental results show that the use of the polypropylene fibers for the yarns in high-pile fabrics and the use of the cotton yarn in ground yarns have tend to provide the best comfort.

RETRACTED: Assessment of the effects of Fe2O3 nanoparticles on water permeability, workability, and setting time of concrete

The purpose of this study is to investigate the percentage of water absorption, velocity of water absorption, coefficient of water absorption, workability, and setting time of binary blended concrete with partial replacement of cement by 0.5, 1.0, 1.5, and 2.0 wt.% of Fe2O3 nanoparticles. The results showed that using Fe2O3 nanoparticles up to maximum replacement of 2.0% produces concrete with improved resistant to water permeability. Fe 2O3 nanoparticles can improve the filler effect and also the high pozzolanic action of fine particles increases substantially the quantity of C—F—H gel. If this phenomenon joints with low water-to-cement ratio, it can improve the microstructure in the interfacial transition zones and thus the value of C—F—H gel results in decreasing the water permeability. The results also show that the workability and setting time of fresh concrete were decreased by increasing the content of Fe2O 3 nanoparticles.

Fases da germinação de sementes de Annona emarginata (Schltdl.) H. Rainer em diferentes temperaturas

O presente trabalho foi realizado com o objetivo de identificar as fases da germinação de sementes de araticum-de-terra-fria (Annona emarginata (Schltdl.) H. Rainer) sob diferentes temperaturas. Para tanto, o trabalho foi dividido em dois experimentos: um para a determinação das fases I e II da germinação, e outro para a fase III. O delineamento experimental foi o inteiramente casualizado, com 3 tratamentos e 4 repetições de 25 sementes por parcela, em ambos os experimentos. Os tratamentos foram constituídos pelas temperaturas constantes de 25ºC e 30ºC e temperatura alternada de 20-30ºC (8-16 h, respectivamente), com luz constante. As variáveis analisadas foram a variação do grau de umidade ao longo do tempo (experimento 1), a porcentagem e a velocidade média de germinação (experimento 2). Os dados foram submetidos à análise de variância, as médias comparadas pelo teste Tukey, a 5% de probabilidade e regressão polinomial. A variação do grau de umidade ao longo do tempo foi estudada através da regressão não linear monomolecular, com os parâmetros das funções comparados conforme os tratamentos, ajustados, submetidos à análise de variância e teste Tukey, a 5% de probabilidade. Observou-se que as sementes mantidas a 30ºC apresentaram maiores valores para velocidade de aquisição de água, atingindo 27,85% de grau de umidade na mudança da fase I para a fase II. Quando as sementes foram submetidas a 25ºC, a fase I teve duração de 60 horas, atingindo 28,35% de grau de umidade e, sob 20/30ºC, a fase durou 72 horas, alcançando 28,33% de grau de umidade. Embora 30ºC tenha promovido a maior velocidade de embebição, não refletiu em maior porcentagem de germinação (fase III), que foi observada nas sementes mantidas a 20/30ºC.

VARIEDADES DE SOJA DIFEREM NA VELOCIDADE E CAPACIDADE DE ABSORVER ÁGUA

As sementes iniciam a retomada dos processos metabólicos a partir da embebição. Esta supre a necessidade de água para reduzir a resistência mecânica do tegumento, hidratar o embrião e cotilédones, induzindo o embrião a ativar enzimas que aceleram o processo de quebra de materiais de reserva usados para dar início à germinação da semente. Este experimento, realizado na Faculdade de Agronomia da Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, no ano de 1993, objetivou avaliar o comportamento de cultivares de soja quanto à capacidade máxima e velocidade de absorção de água, em intervalos de hora, até oito horas consecutivas, quando em embebição total em água. Foram utilizadas sementes de 17 cultivares com tamanho uniformizado para diâmetro maior que 6,3 mm e ausência de rachaduras no tegumento quando observadas através de lupa. A cultivar ‘RS 6 Guassupí’ apresentou a maior velocidade e capacidade total de absorção de água. ‘FT Abyara’ e ‘Bragg’ apresentaram a menor velocidade e menor capacidade total de absorção nas primeiras horas de embebição, mas nas ultimas horas foi a ‘RS 7 Jacuí’ que apresentou a menor capacidade de absorção. Este estudo permitiu concluir que existem diferenças na velocidade e na capacidade total de absorver água entre as cultivares testadas, devido a alguma característica distinta entre elas, que não foi investigada neste trabalho e que torna suas sementes mais ou menos permeáveis a água.

RESEARCH ON WET-STRENGTH PAPER

The authors have researched on a manufacturing method of the wet-strength paper, the copolymerized compounds of melamine and formaldehyde.To make wet-strength paper, resin must be prepared through two stages, before it added into beater.As the first stage, various methylolcompounds are needed to be made of melamine and formaldehyde. Those methylolcompounds (involving T.M.M., M.T.M.M., H.M M., & M.M.) are not, stricktly speaking, chemically simple ones, but such as somewhat polymerized products ; and the degree of polymerization, it is consiered, plays important.Methylolcompounds gained in such a method must be dissolved by means of acid be again still more polymerized.Such is the second stage : which is generally called as ripening. Watching the progress of ripening by measuring viscosity, resin is to be added into beater just before Tixotropie is caused. The progress of the ripening is different, according to the kinds natures of methylolcompounds in the first stage, to the kinds and concentration of dissolving acid, to the concentration of resin in the solution and to the ripening temperture.Papers, manufactured by the ordinary method such as resin added into beater, to get the nature of wetstrength, which owes to the chemical bond caused by the resin permeated among the cellulosic fibres. The definition of the wet-strength has not been fixed in the academic world. What is very slow of the velocity of water-absorption is rather called as water-proof ; wet-strength, in addition to this, is to be of such a nature as holds strength in spfte of absorbing wet. The authors, meaning to fix the definition of wet-strength, soaked some papers for 10 minites, pressed them between filterpapers by a settled pressure, and thus called the papers as of wet-strength, which, through such a disposal, holds more than .30% of wet as well as 30% of dry-strength.As in the Japanese report, the authors have succeeded in manufacturing papers equal to the map-papers made in U. S. A.