EXPLORING THE EFFECT OF ORGANIC ADDITIVES ON PHYSICAL PROPERTIES OF BITUMEN

Warm additives had wide popularity in recent years due to saving in energy and lowering emissions dealt with asphalt mixture production. Warm Mix Asphalt (WMA) is produced by using foaming technology or reducing -viscosity additives of binder to enhance the rheological properties. In this study, organic-based additives (Asphaltan A and Asphaltan B) are used to investigate their effect to minimize the viscosity and lower the temperature of asphalt mixture production. Bitumen is mixed with three doses of each additive: 1, 2, and 3% of its weight. The binder viscosity was measured by rotational viscometer with and without the additives at three different temperatures. The study showed that the organic additives have a positive impact on the behavior of the binder in terms of viscosity reduction and made enhancements in terms of bitumen properties. This result could be useful in the reduction of production temperature and quantity of odour emissions

Inhibitory Effect of Cow Urine against Colletotrichum capsici Isolated from Anthracnose of Chilli (Capsicum annuum L.)

Cow urine has got several applications in agriculture. It is shown to possess inhibitory activity against many phytopathogenic fungi and bacteria. Among various diseases of Chilli, anthracnose is the most important disease which results in drastic reduction in yield. The present study was conducted with an aim to determine antifungal efficacy of cow urine against Colletotrichum capsici isolated from anthracnose of chilli (Capsicum annuum L.). Poisoned food technique was employed to determine antifungal activity of different concentrations of cow urine (5, 10 and 15%). Cow urine was found to display concentration dependent inhibitory activity against fungal growth. An inhibition of >50% was observed at 5% concentration. In conclusion, the use of cow urine can be the costeffective and eco-friendly approach for controlling anthracnose in chilli

Clarification of factors that affect the flux performance of hollow fiber membranes during ultrafiltration using design of experiments

In this paper, the separation of humic substances from oily wastewater was investigated using Hollow Fiber membranes. Consideration was given to the increse of membrane permeability or flux of the Ultrafiltration process. Specifically, several factors which were temperature, pressure, time, pH and surface area of membrane, were studied. The Design of Experiments (DOE) methodology was used to investigate the effect of the factors. From the analysis of variance (ANOVA), it was determined that the pH and temperature of feed solution, time of separation process and transmembrane pressure are significant. The results of this study help to increase the permeability of membranes, thus contributing to a more sustainable filtration system

Modeling of preparation conditions of PES ultrafiltration hollow fiber membranes using statistical regression techniques

Mathematical modeling of the spinning process is crucial for a better understanding of the process variables and process functionality in membrane development. Due to the broad use and key importance of mathematical models in chemical process engineering, experimental design is becoming essential for the rapid development and validation of these empirical models. This work used the design of experiment methodology and aimed to predict the performance of ultrafiltration systems for water treatment by considering the statistical regression technique as an important approach for modeling flux. The utilization of regression modeling was also explored to show the principle elements for predicting flux in the spinning process. In order to investigate how proficient the statistical regression technique is at approximating the predicted value for flux, a real spinning experiment was conducted in this study. In this experiment, 30 samples of data were collected based on a half fractional factorial experiment with design resolution V, as well as 4 replications of center points and 10 axial points. The spinning factors that were investigated are the dope extrusion rate, air gap length, coagulation bath temperature, bore fluid ratio, and post-treatment time for predicting the corresponding flux. The regression model obtained shows that there is a correlation between the experimental data and predicted values. The results of the proposed model can be used to give a good prediction of the spinning process during membrane fabrication

Numerical Study of N-Heptane Fuelled Hcci Under Different Air Fuel Ratio and Inlet Air Temperature

This paper examines on numerical modeling of Homogenous Charge Compression Ignition (HCCI) engine model using n-heptane as base fuel. The parameters used in this study is different air to fuel ratio (AFR) (25, 30, 35, 40, 45, 50) and different air inlet temperature (25°C, 50°C, 75°C, 100°C). Performance and emission characteristics of n-heptane were investigated at constant engine speed of 1000 rpm in a HCCI engine model. The effects of inlet air temperature were also examined. The test results showed that brake power, brake mean effective pressure and brake specific fuel consumption decreased when increased AFR and inlet air temperature. Meanwhile, brake thermal efficiency shows an increase when increase when AFR and temperature of the inlet increased. The test results also showed that NOx, CO and HC emissions decreased with the increase of inlet air temperature for all AFR value. Overall, this numerical model can be used to predict the performance and emission of the HCCI engine

Optimization of callus induction and regeneration system for Pakistani wheat cultivars Kohsar and Khyber-87

Wheat is a member of family Poaceae. It is the major staple food of Pakistan. The present study was done to improve the regeneration of two commercially grown wheat varieties Kohsar and Khyber-87.Mature embryos were used as explants. Five different concentrations of 2,4-D; 2, 2.5, 3, 3.5 and 4 mg/L were used for callus induction. For regeneration, initially different concentrations (0.1 to 0.2) of IAA(indole-3-acetic acid) and BAP (6-benzylaminopurine) were experimented. The best combination of these hormones that is, 0.1 mg/L IAA and 0.5 mg/L BAP were further subjected to experimentation along with different concentrations of kinetin; 0.1, 0.2, 0.3, 0.4, 0.5 and 1 mg/L. Maximum calli of Kohsar (83.3%) was obtained at 3 mg/L 2,4-D whereas for Khyber-87 maximum callus induction (71.70%) was obtained at 3.5 mg/l 2,4-D. The maximum regeneration of both Kohsar and Khyber-87 (80.5 and 62.2%, respectively) were obtained at the combinations of 0.1 mg/L IAA, 0.5 mg/L BAP and 0.5 mg/L kinetin

Hollow-core photonic crystal fiber refractive index sensor based on modal interference

A refractive index sensor based modal interference in hollow core photonic crystal fiber (HCPCF) is proposed and demonstrated. The sensor is realized by splicing both ends of a HCPCF section to single mode fiber (SMF). At both splicing points, the HCPCF air holes are fully collapsed by the arc discharge. The collapsed regions excite and recombine core and cladding modes which formed modal interference for sensing purpose. The HCPCF sensor is tested in sugar solution and the response is measured from the wavelength shift in the interference spectra. The achieved sensitivity and resolution are 36.184 nm/RIU and 5.53-10-4 RIU, respectively, in refractive index range between 1.3330 and 1.3775. Result also shows that the sensor has a small temperature sensitivity of 19 pm/°C in the range of 35.5°C to 60.5 °C. The propos sensor potentially can be applied in biomedical, biological and chemical applications

Performance of radial point interpolation method in solving kinematic wave equation for hydrologic modelling

This paper presents the solution of the kinematic wave equation using a meshless radial point interpolation method (RPIM). The partial differential equation is discretized using a Galerkin weighted residual method employing RPIM shape functions. A forward difference scheme is used for temporal discretization, while the direct substitution method is employed to solve the nonlinear system at each time step. The formulation is validated against solutions from conventional numerical techniques and physical observation. In all cases, excellent agreements are achieved and hence the validation of the proposed formulation. Optimum values of the multi-quadrics shape parameters were then determined before the assessment of the performance of the method. Based on the convergence rate, it has been shown that the proposed method performs better than the finite difference method and equivalent to the finite element method. This highlights the potential of RPIM as an alternative method for hydrologic modeling

Enhanced meshfree RPIM with NURBS basis function for analysis of irregular boundary domain

Radial Point Interpolation Method (RPIM) has become a powerful tool to numerical analysis due to its ability to provide a higher-order approximation function with the Kronecker delta property, by which the field nodes can be fitted exactly. However, one of the major drawbacks of RPIM is the inefficiency in handling irregular domain problems. This paper presents an enhanced RPIM formulation that employs Non-Uniform Rational B-Splines (NURBS) basis functions to represent the exact geometry of the boundary domain. The NURBS is a mathematical model which provides an efficient and numerically stable algorithm to exactly represent all conic sections in engineering modelling. Taking advantage of the flexibility and adaptivity of RPIM approximation and the accuracy of geometric representations by NURBS, this new method is able to improve geometry accuracy and flexibility in numerical analysis, thus providing a better and more rational approach to analyze irregular domain problems. Numerical problem of steady heat transfer considering curved beam is presented to verify the validity and accuracy of the developed method. The essential boundary condition can simply be imposed using direct imposition as in Finite Element Method (FEM). The result shows that the RPIM/NURBS achieved the converged solution much faster than conventional RPIM and FEM, with the number of nodes required only less than 200 for an error of less than 0.01%. This shows the potential of the developed method as a powerful numerical technique for future development