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Uniqueness of Solution of Upper Convected Maxwell Flows Through Some Uniform Tubes
Escolar ( Lepidocybium flavobrunneum ) and oilfish ( Ruvettus pretiosus ) are by-catches of tuna and classified as deep-sea fish that are able to occupy a depth of 200 meters under ocean level. These fish are able to be used as a fount of fish oil (FO) production due to their high fat content, up to 13.30%. This research objectives to determine fat content, oil yield, fatty acid (FA) profiles, oxidation parameters, and the potential of deep-sea FO as immunostimulants agent by in vitro method. The research method employed was wet lab-based, encompassing the extraction of deep-sea fish oil using the wet rendering method at a temperature of 40, 50, 60, and 70 °C for 1 hour utilizing a water bath. The extracted oil yield was quantified, and its potential as an immunostimulant was identified through an in vitro MTT assay. The dominant FA in escolar and oilfish were oleic acid (C18:1n-9c) 26.85% (w/w) and 23.02% (w/w), respectively. Splenocyte proliferation activity showed that oilfish and escolar FO were able to raise splenocyte proliferation, so they got the potential to act as immunostimulants.
Concrete is weak in tension, causing brittle failure without warning. Fiber is one of the simplest techniques to increase tensile strain. Several kinds of fibers (synthetic) are available such as steel fiber, glass fiber, and carbon fiber. However, these fibers are expensive and cannot be easily accessible. Researchers use agricultural fiber in concrete instead of synthetic fibers to offset this deficiency. Although, several studies have shown that agricultural fiber may be utilized to increase concrete tensile strength. However, a details review is required which combines all relevant information and the reader can evaluate the benefits of agricultural fiber. Therefore, this review focus on a comprehensive and up-to-date overview of the impact of agricultural fiber on concrete slump flow, mechanical quality, and durability. Furthermore, scanning electronic microscopy, enhancement methods, and agricultural fiber-reinforced concrete (AFRC) applications are also reviewed. Five different types of agricultural fiber including coconut, jute, banana, rice straw, and hemp fibers were selected. According to the findings, agricultural fiber increased concrete’s mechanical and durability qualities while comparably decreasing the slump. The optimum dose is essential as the higher dose adversely affects mechanical performance. The typical optimum amount varies from 1% to 2% by weight/volume of the binder. Among various types of agricultural fiber, coconut fiber is super performance. Less research is carried out on hemp, straw ash, and banana fibers than on coconut and jute fibers.
Natural fibers are an excellent alternative since they are inexpensive and easily accessible in fibrous form. Several researchers claim that jute fiber (JTF) can be used in concrete to improve its strength and durability performance. This review describes the characteristics and potential uses of some jute fibers in concrete. The main theme of this review is to summarize the effect of JTF on fresh properties of concrete, strength parameters, and durability characteristics. It can be concluded that jute fibers improved strength and durability aspect but decreased the fluidity of concrete in a similar way to synthetic fibers. However, there is little research available on the durability of concrete reinforced with JTF. Furthermore, the optimum percentage of JTF in concrete is critical as the higher dose adversely affects strength and durability characteristics due to lack fluidity. The typical range of optimum dose of JTF varies from 1% to 2% depending on the length and diameter of jute fibers. The review also identifies the key for future researchers to further, enhance the properties of concrete reinforced with JTF.
Catfish (Pangasius pangasius) is one of popular freshwater fisheries commodities and its growth relatively fast. Fish growth and survival were affected by feed. The high-quality feed is expensive so it can be added with alternative feed ingredients such as Seligi leaf flour. Seligi leaf flour has 11.53% protein and 15.48% crude fibre. However, high crude fiber can be overcome by fermentation using probiotics. This study aims to determine the use of Seligi leaf flour fermentation (Phyllanthus buxifolius) in feed on fat retention and energy retention of catfish (Pangasius pangasius). This study used an experimental method with a completely randomized design (CRD) consisting of four treatments (0%, 2%, 4%, and 6%) with five replications. Data analysis used Analysis of Variance (ANOVA) and continued with Duncan’s Multiple Range Test. The results of the research that had been carried out were significant differences (P <0.05) on fat retention and energy retention of catfish. The highest fat retention and energy retention was in P2 treatment, while the lowest fat retention and energy retention was in P0 treatment.
Concrete as the most common building material possess very less tensile strength. To overcome this problem, different types of fibers are added with concrete matrix from from the ancient era. Investigation of fiber reinforced concrete reveals that short length fibers help in bridging micro cracks while long fibers are able to arrest macro cracks and also enhance toughness of the member. The combinations of different lengths of fibers are found to be more effective than mono length fibers for a fixed volume fraction of fiber. Combination of different lengths of fibers is termed as hybrid fiber and when different lengths of fibers are mixed in concrete it is termed as graded fiber. This investigation aims in finding out the enhancement of mechanical properties of a particular grade of concrete with addition of different lengths of fibers and with graded fiber with a fixed amount of fiber. M30 grade concrete with 1.5% weight of fiber is considered in this present investigation. The results shows that the mechanical strength of concrete increases with addition of fibers, decreases with long length of fibers with same volume fraction of fiber and increases with graded fiber. Workability decreases with addition of fiber, with higher length of fiber. There is enhancement of workability with graded fiber than same volume fraction of long fibers.
An improved technique for determining the strength of reinforced beams with polymer composite reinforcement based on a nonlinear deformation model using a three-line diagram of concrete deformation under uniaxial compression with an elastic, elastic-plastic zone and a concrete softening zone is considered and proposed. The features of the strength analysis of beams with fiberglass reinforcement are revealed. The calculation method presented in this article allows us to minimize the use of empirical coefficients to determine the height of the compressed zone of concrete and at the same time does not lead to labor-intensive calculated dependencies. The method is based on the use of the Euler – Bernoulli beam theory and the use of physical stress-strain relations for concrete. This calculation method allows you to set accurately the height of the compressed zone of concrete, and accordingly the strength of the beam elements in the normal section. Good results of comparison with experimental data were obtained.
The primary reason for the curing of concrete is to complete the hydration reactions of cement with other materials. However, the problem occurs when required ideal curing becomes challenging due to various anomalous structural elements. To mitigate this issue, a bacterial solution known as Effective Microorganism (EM) has been introduced as a self-curing agent that has favourable surface tension, viscosity and solubility in water. Different percentage of water i.e. 0%, 5%, 10%, 15%, 20%, and 25% were replaced with EM. The optimisation of percentage replacement of EM was based on the compression strength and water loss of concrete. The percentage of EM with 10% water replacing showed better compression strength as compared to other percentage replacements. With the optimum 10% percentage, compression strength was found 42 MPa and 49 MPa compared with 33 MPa and 43 MPa with control samples with air and water curing respectively. The water loss also reduced 2% with 10% EM replacement compared to the control sample. Results showed that 10% of EM is the optimum value to get desirable properties of concrete in air and water curing. EM can be used as a new self-curing agent as a novel approach in the area of self-curing concrete.
Nile tilapia has high economic value, in its cultivation, to optimize the growth and survival rate of Nile tilapia could be done by adding vitamin C in its feed as antioxidant. However, vitamin C could not be synthesized in the fish body and expensive. Mangrove leaves Avicennia rumphiana contains antioxidant that suitable as the alternative of antioxidant likes vitamin C. This study aimed to observe the using of feed additive of mangrove leaves flour as antioxidant towards the growth and survival rate of Nile tilapia. This research applied a completely randomized design method which consist both of four treatments and replications that involve 0.02gr/kg vitamin C (K), amount of 0.2gr/kg, 0.4gr/kg, 0.6gr/kg mangrove leaves flour (P1, P2, P3). The result showed that the using of mangrove leaves flour as feed additive in commercial feed in 30 days at 0.02gr/kg has influenced the development of growth and survival rate of Nile tilapia. Therefore, it has proved that mangrove Avicennia rumphiana leaves flour is qualified to be the alternative of feed additive antioxidant in fish feed.
The aim of the study is to validate the effect of glass fiber and polypropylene fiber on improving the mechanical and durability properties of concrete. In this regard, glass fiber, polypropylene fiber and hybrid fiber were added to concrete, respectively. This paper conducted the compressive and bending flexural tests to confirm that the fiber enhances the mechanical properties of concrete. In order to evaluate the durability of fiber reinforced concrete, the rapid chloride migration test and rapid chloride penetration test were carried out. The comparisons of experimental results illustrate that the hybrid fiber reinforced concrete has the most significant effect on the concrete properties improvements. Moreover, comparing with the glass fiber reinforced concrete, the polypropylene fiber reinforced concrete plays a better performance on mechanical and durability properties.
Aliphatic hydrocarbons in the sediments of the estuarine mangrove forests of Cochin region, Southwest coast of India were characterized to assess the sources of organic matter (OM) and to validate the effectiveness of the various geochemical indices to identify multiple OM sources and the complex geochemistry of these tropical coastal environments. The total concentration of the n-alkanes varied from 34.74 to 59.17 µg/g [dry weight (dw)] in mangrove sediments, to values between 19.67 and 20.98 µg/g in estuarine sediments. The n-alkane distribution in the study region indicated a strong odd over even predominance in both mangrove and estuarine sediments. Assessment using terrestrial OM indices such as Carbon Preference Index (CPI), Terrigenous Aquatic Ratio (TAR), and Terrestrial Marine Discriminant (TMD) suggested that a large fraction of OM in the mangrove sediments was derived from mangrove plant litter and a better preservation of mangrove OM in the sedimentary environment has occurred. These findings are supported by the higher content of total lipid, tannin, and lignin, as well as by the depleted δ13C values. Low ratios of CPI, TAR, and TMD at estuarine sites E2 and E3 indicated a mixed origin of OM. Natural or biogenic indices such as natural n-alkanes ratio (NAR), Σn-alkanes/n-C16, n-C29/n-C17, and LMW/HMW revealed that all the mangrove stations and the estuarine station E1 received OM from natural or biogenic sources, whereas a significant anthropogenic input was noticed for estuarine stations E2 and E3. Indices like Pr/Ph, Pr/n-C17, Ph/n-C18 further confirmed the mixed nature of OM accumulated under the anoxic environment.
Flow of a power-law fluid with a suddenly applied arbitrary time-dependent pressure gradient in a horizontal circular tube is presented. The momentum equations are solved numerically using a implicit finite-difference technique for the time-dependent velocity profiles for both start up and oscillating pressure gradients. Dimensionless curves are presented showing velocity profile development and phase angle variation for a variety of power-law index values.
The main objective of this work is to examine in detail basic unsteady pipe flows and to investigate any new physical phenomena. We take the viscoelastic upper-convected Maxwell fluid as our non-Newtonian model and consider the flow of such a fluid in pipes of uniform circular cross-section in the following three cases: 1.(a) when the pressure gradient varies exponentially with time;2.(b) when the pressure gradient is pulsating;3.(c) a starting flow under a constant pressure gradient.In the first problem we looked separately at the pressure gradient rising exponentially with time and falling exponentially with time, i.e. the pressure gradient is proportional to e±α2τ. The behaviour of the flow field depends to a large extent on β where β2 = α2(1 ± Hα2) with H being the quotient of the Weissenberg and Reynolds numbers. In both cases for small |βη|, η being the radial distance from the axis, the velocity profiles are seen to be parabolic. However, for large |βη| the flows are vastly different. In the case of increasing pressure gradient the flow depicts boundary-layer characteristics while for decreasing pressure gradient the velocity depends on the wall distance.The case of a pulsating pressure gradient is investigated in the second problem. Here the pressure gradient is proportional to cos nτ. Again the flow depends to a large extent on a parameter β (β2 = in − n2H). For small values of |βη| the velocity profile is parabolic. However, it is found that, unlike Newtonian fluids, the velocity distribution for the upper-convected Maxwell fluid is not in phase with the exciting pressure distribution. In the case of large |βη| the solution displays a boundary-layer characteristic and the phase of the motion far from the wall is shifted by half a period.The final problem examines a flow that is initially at rest and then set in motion by a constant pressure gradient. A closed form solution has been obtained with the aid of a Fourier-Bessel series. The variation of the velocity across the pipe has been sketched and comparison made with the classical solution.
The transient response of an upper-convected Maxwell fluid flow in a circular tube is analysed by variational approach of
Kantorovich and the method of finite difference. The solution of the variational method is in agreement with the numerical
results by the difference schemes. The results show that the method of Kantorovich is suitable for the study of non-steady
flow of non-Newtonian fluids and the effect of elasticity of the fluid has an influence on the non-steady flow.
Solutions to the equation of motion have been obtained for a viscoelastic fluid which obeys an Oldroyd three‐constant constitutive equation. The solutions apply to a fluid at rest which at zero time is subjected to (1) a step change in pressure gradient or (2) a sinusoidally varying pressure gradient. From these results one can predict the response of the fluid to an arbitrary time‐dependent pressure gradient. Curves are presented which show how the flow of a viscoelastic fluid, when subjected to a step change in pressure, can overshoot the final steady‐state flow. Amplitude and phase relationships between different variables are presented for a sinusoidally varying pressure gradient. Comparisons are made with available experimental data.
The transient response of a non-Newtonian power-law fluid to several assumed forms of pressure pulse in a circular tube is analysed by the semi-direct variational method of Kanntovorich. Velocity profiles are shown for several power-law indices, and by comparing the results for the Newtonian case with the exact solution given by Szymanski, it is observed that the results are good to 5%. More accurate solutions have been found for the case involving Newtonian fluid flow. New results are reported concerning the effect of a triangular pressure pulse on the development and transient response of the flow field of a non-Newtonian fluid.
L'tude porte sur la thorie de lcoulement non permanent d'un fluide visqueux incompressible dans de canaux rectangulaires d'allongement divers, sous l'influence d'un gradient de pression arbitraire, dpendant du temps. Des solutions ont t obtenues dans 4 cas particuliers: 1. gradient de pression impulsif, 2. gradient de pression constant et tabli brusquement, 3. gradient de pression en fonction harmonique du temps, 4. gradient de pression une composante constante et une composante harmonique. On donne les rpartitions de vitesse, les coefficients de frottement et la dissipation d'nergie par unit de longueur.
The transient thermal response of a power law type non-Newtonian, laminar boundary layer flow past a flat plate is investigated. Consideration is given to the case of a step change in surface temperature. The transient heat flux and details of the temperature field are obtained and have been illustrated graphically. The range of Prandtl numbers investigated was 5–1000 while the viscosity index was allowed to vary 0.1–5.0.