• Computers and Concrete
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• v.5 no.3
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• pp.243-260
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• 2008

The present article summarises the fundamental characteristics of concrete behaviour which underlie the formulation of an engineering finite element model capable of realistically predicting the behaviour of (plain or reinforced) concrete structural forms in a wide range of problems ranging from static to impact loading without the need of any kind of re-calibration. The already published evidence supporting the proposed formulation is complemented by four additional typical case studies presented herein; for each case, a comparative study is carried out between numerical predictions and the experimental data which reveals good agreement. Such evidence validates the material characteristics upon which the FE model's formulation is based and provides an alternative explanation regarding the behaviour of structural concrete and how it should be modelled which contradicts the presently (widely) accepted assumptions adopted in the majority of FE models used to predict the behaviour of concrete.

• Coupled systems mechanics
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• v.1 no.1
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• pp.59-78
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• 2012

The available analytical methods of analysis for laterally loaded piles in level ground cannot be directly applied to such piles in sloping ground. With the commercially available software, the simulation of the appropriate field condition is a challenging task, and the results are subjective. Therefore, it becomes essential to understand the process of development of a user-framed numerical formulation, which may be used easily as per the specific site conditions without depending on other indirect methods of analysis as well as on the software. In the present study, a detailed three-dimensional finite element formulation is presented for the analysis of laterally loaded piles in sloping ground developing the 18 node triangular prism elements. An application of the numerical formulation has been illustrated for the pile located at the crest of the slope and for the pile located at some edge distance from the crest. The specific examples show that at any given depth, the displacement and bending moment increase with an increase in slope of the ground, whereas they decrease with increasing edge distance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.9
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• pp.1579-1588
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• 2003

In this paper, the finite element equations for the transient linear viscoelastic stress analysis are presented in time domain, whose variational formulation is derived by using the Galerkin's method based on the equations of motion in time integral. Since the inertia terms are not included in the variational formulation, the time integration schemes such as the Newmark's method widely used in the classical dynamic analysis based on the equations of motion in time differential are not required in the development of that formulation, resulting in a computationally simple and stable numerical algorithm. The viscoelastic material is assumed to behave as a standard linear solid in shear and an elastic solid in dilatation. To show the validity of the presented method, two numerical examples are solved nuder plane strain and plane stress conditions and good results are obtained.

• Structural Engineering and Mechanics
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• v.25 no.6
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• pp.653-674
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• 2007

This paper discusses the application of piezoelectric sensors used for evaluation of damping ratio of PVC plastics. The development of the mathematical formulation based on the Empirical Mode Decomposition for calculating the damping coefficient and natural frequency of the system is presented. A systematic experimental and analytical investigation was also carried out to demonstrate the integrity of several methods commonly used to evaluate the damping of materials based on a single degree freedom formulation. The influence of the sensors' location was also investigated. Besides the commonly used methods, a newly emerging time-frequency method, namely the Empirical Mode decomposition, is also employed. Mathematical formulations based on the Hilbert-Huang formulation, and a frequency spacing technique were also developed for establishing the natural frequency and damping ratio based on the output voltage of a single piezoelectric sensor. An experimental investigation was also conducted and the results were compared and verified with Finite Element Analysis (FEA), revealing good agreement.

• Korean Journal of Environmental Agriculture
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• v.15 no.1
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• pp.116-127
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• 1996

Recent development in Japan on jumbo formulation of pesticides for paddy application by hand throw was reviewed. In addition, the diffusion of liquid formulations in water was examined to establish the research strategy for the jumbo formulation. Research on jumbo formulation in Japan has been focused on gas-generating formulations and self-emulsifiable formulations. Although continuous efforts to minimize the problem of pesticide deposit on the treated site have been made for the gas-generating formulations, much work is still needed to establish a generally acceptable formulation method and to commercialize a herbicide formulation. The self-emulsifiable jumbo formulations have recently been investigated. These formulations could simply be processed and showed relatively high biological efficacy. The emulsifiable concentrate was more diffusible than the suspension concentrate in water. The diffusion of the emulsifiable concentrate was not greatly disturbed by floating obstacles. And the diffusion rate was high when the specific grabity was lower than one.

• CELLMED
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• v.10 no.2
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• pp.16.1-16.8
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• 2020

Standardization of drug deals with confirmation of drug identity and determination of drug quality and purity. Unani herbal formulations are used in traditional medicine for the treatment of various diseases. Cancer is a disease which causes abnormal, uncontrolled growth of body tissue or cells, which tend to proliferate in an uncontrolled way. Spread of cancer from site of origin to other organs of the body is called metastasis. It is a hyper proliferative disorder involving, transformation, dysregulation of apoptosis, invasion and angiogenesis. The present study aimed to standardize a classical Unani formulation (CUF) described as anticancer properties. The CUF has been used for anti-cancerous activity (Dāfi'-i-saraṭān) in human population by Unani physicians for centuries. The standardization parameters carried out for classical Unani formulation are pharmacognostical studies, physicochemical parameters, high-performance thin layer chromatography (HPTLC), microbial load, aflatoxins, and heavy metals revealing specific identities and to evaluate Pharmacopoeial standards. Experiment and the data obtained established the Pharmacopoeial standards for this formulation for identification and quality control purpose. The CUF has been successfully standardized and standard operating procedures (SOPs) for its preparation has been laid down which may serve as a standard reference in future. The standardization data of this formulation may be used as a standard guideline for preparation of the formulation in future.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.29-34
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• 2005

W/O/W (water-in-oil-in-water) type multiple emulsion was applied to improve the storage stability of an antagonistic microorganism, Burkholderia gladioli. Encapsulation of microorganism into a W/O/W emulsion was conducted by using a two-step emulsification method. W/O/W emulsion was prepared by the incorporation of B. gladioli into rapeseed oil and the addition of polyglycerin polyriconolate (PGPR) and castor oil polyoxyethylene (COG 25) as the primary and secondary emulsifier, respectively. Microcrystalline cellulose was used as an emulsion stabilizer. To evaluate the usefulness of W/O/W emulsion formulation as a microbial pesticide for controlling the bacterial wilt pathogen (Ralstonia solanacearum), the storage stability and antagonistic activity of emulsion formulation were tested in vitro. The storage stability test revealed that the viability of formulated cells in emulsion was higher than that of unformulated cells in culture broth. At $4^{\circ}C$, the viabilities of formulated cells and unformulated cells at the end of 20 weeks decreased to about 2 and 5 log cycles, respectively. At $37^{\circ}C$, the viability of formulated cells decreased to only 2 log cycles at the end of storage. On the other hand, the viable cells in culture broth were not detected after 13 weeks. In activity test, formulated cells in emulsion were more effective in inhibiting the growth of pathogen than unformulated cells in culture broth. Unformulated cells completely lost their antagonistic activity during storage under similar conditions. The W/O/W multiple emulsion formulation was shown to be useful as the novel liquid formulation for biological control.

• Journal of Pharmaceutical Investigation
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• v.31 no.3
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• pp.167-172
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• 2001

All-trans retinoic acid (ATRA), vitamin A acid, has been shown to exert anticancer activity in a number of types of cancers, particularly in acute promyelocytic leukaemia (APL). Due to its highly variable bioavailability and induction of its own metabolism after oral treatment, development of parenteral dosage forms are required. However, its poor aqueous solubility and chemical unstability give major drawbacks in parenteral administration. This study was undertaken to investigate a possibility to develop a parenteral formulation of ATRA by employing solid lipid nanoparticle (SLN) as a carrier. By optimizing the production parameters and the composition of SLNs, SLNs with desired mean particle size (<100 nm) as a parenteral dosage form could be produced from trimyristin (as solid lipid), Egg phosphatidylcholine and Tween 80 (as SLN stabilizer). The mean particle size of SLN formulation of ATRA was not changed during storage, suggesting its physical stability. Thermal analysis confirmed that the inner lipid core of SLNs exist at solid state. The mean particle size of ATRA-loaded SLNs was not significantly changed by the lyophilization process. ATRA could be efficiently loaded in SLNs, while maintaining its anticancer activity against HL-60, a well-known APL cell line. Furthermore, by lyophilization, ATRA loaded in SLN could be retained chemically stable during storage. Taken together, our present study demonstrates that physically and chemically stable ATRA formulation adequate for parenteral administration could be obtained by employing SLN technology.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.4
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• pp.328-333
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• 2014

A hybrid particle-mesh method based on the vorticity-velocity formulation for solving the incompressible Navier-Stokes equations is a combination of the Vortex-In-Cell(VIC) method for convection and the penalization method for diffusion. The key feature of the numerical methods is to determine velocity and vorticity fields around a solid body on a temporary grid, and then the time evolution of the flow is computed by tracing the convection of each vortex element using the Lagrangian approach. Assuming that the vorticity and velocity fields are to be computed in time domain analysis, pressure fields are estimated through a complete set of solutions at present time step. It is possible to obtain vorticity and velocity fields prior to any pressure calculation since the pressure term is eliminated in the vorticity-velocity formulation. Therefore, pressure field is explicitly treated by solving a suitable Poisson equation. In this paper, we propose a simple way to numerically implement the vorticity-velocity-pressure formulation including a penalty term. For validation of the proposed numerical scheme, we illustrate the early development of viscous flows around an impulsive started circular cylinder for Reynolds number of 9500.

• Ocean Systems Engineering
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• v.7 no.1
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• pp.21-38
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• 2017

In real sea environments, excessive dynamic axial tension variations can be exerted on the top-tensioned risers (TTRs) and lead to structural integrity issues. The traditional riser-tension-variation analysis, however, by using parametric formulation is only conditionally valid under certain strict limits and potentially underestimates the total magnitudes of tension variations. This phenomenon is especially important for the long stroke tensioner in dry-tree semisubmersible with larger global heave motion and longer stroke. In this paper, the hydro-pneumatic tensioner (HPT) is modeled in detailed component-level which includes a set of hydraulic and pneumatic components. The viscous fluid frictional effect in the HPT is considered. The main objectives are (i) to develop a detailed tension variation model of the HPT; (ii) to identify the deviations between the conventional parametric formulation and component-level formulation; (iii) to numerically analyze the tension variation of long stroke tensioner in a dry-tree semisubmersible (DTS). The results demonstrate the necessity of component-level formulation for long stroke tensioner in the development of DTS.