Papers by Wanwisa Skolpap
This study aimed at investigating the influence of commercial transfection reagents (Prime-Fect, ... more This study aimed at investigating the influence of commercial transfection reagents (Prime-Fect, Leu-Fect A, and Leu-Fect C) complexed with different siRNAs (CDC20, HSP90, Mcl-1 and Survivin) in MDA-MB-436 breast cancer cells and the impact of incorporating an anionic additive, Trans-Booster, for improving in vitro gene silencing and delivery efficiency. Gene silencing was quantitatively analyzed by real-time RT-PCR while cell proliferation and siRNA uptake were evaluated by the MTT assay and flow cytometry, respectively. Amongst the investigated siRNAs and transfection reagents, Mcl-1/Prime-Fect complexes showed the highest inhibition of cell viability and most effective siRNA delivery. The effect of various formulations on transfection efficiency showed that a anionic additive with 1:1 ratio with siRNA was optimal achieving the lowest cell viability compared to untreated cells and negative control siRNA treatment (p<0.05). Furthermore, the combination of Mcl-1 and survivin siRN...
Bioprocess and Biosystems Engineering, 2007
ABSTRACT
The fed-batch optimization of penicillin productivity was applied as an example of optimization a... more The fed-batch optimization of penicillin productivity was applied as an example of optimization algorithm verification. The objective function of this problem was to optimize penicillin productivity by determination of feed rate trajectory. This study compared the optimized results derived from the proposed algorithm and from the iterative dynamic programming. Three decision variables for the proposed algorithm comprised t s (switching time from exponential to linear feeding schedules), K (constant in feed rate equation), and ε ε ε ε ε (a multiplier on substrate requirement). Estimation of this set of decision variables employed Markov chain Monte Carlo procedures (the Gibbs parameter sampling and the Metropolis-Hasting algorithm) using an originally given set of initial values. The optimization procedure was divided into two time periods as follows: i) the time period of exponential feeding policy, t < t s and ii) the time period of linear feeding schedule, t > t s . The calculation procedure of the first period of fermentation time had been proposed by integrating Pontryagin's optimum principle and Luedeking-Piret equation. The feed rate profile during the later period was obtained from the direct substitution of desired substrate requirement derived from Monod equation. The optimal feed-rate profile corresponded to the values of decision variables as follows [t s K ε ε ε ε ε] = [35.937
The purpose of this study was to investigate the maximum annual profit of proposed three project ... more The purpose of this study was to investigate the maximum annual profit of proposed three project plants as follows: (i) a generation process of activated carbon (AC) prepared from coconut shells; (ii) a regeneration process of spent AC obtained from petrochemical industries; and (iii) a project combined the AC generation process with the regeneration process. The maximum annual profit obtained from the sole regeneration plant was about 1.2and 15.4fold higher than that obtained from the integrated and the generation plants, respectively. The sensitivity of selected variables to net present value (NPV), AC sales price was the most sensitive to NPV while fixed costs of generation and regeneration, and variable cost of regeneration were the least sensitive to NPV. Based on the optimal results of each project plant, the economic indicators namely NPV, return on investment (ROI), internal rate of return (IRR), and simple payback period (SPP) were determined. Applying a rule of thumb of 12...
Journal of Pharmaceutical Sciences
Journal of Food Processing and Preservation
The Journal of Supercritical Fluids
Abstract This study aims at investigating the influence of supercritical carbon dioxide (ScCO2) t... more Abstract This study aims at investigating the influence of supercritical carbon dioxide (ScCO2) treatment on the physicochemical properties of cassava–based cellulose. The ScCO2 treatment was performed in a high-pressure vessel by exposing the cellulose to ScCO2 without a co-solvent at variable pressure (P) ranging from 8 MPa to 20 MPa for 60 min. The system temperature (T) was set to 40 °C, 60 °C and 80 °C. Subsequently, a field emission scanning electron microscopy analysis showed that the average fibril diameter of the cellulose was approximately two times less than that of the untreated cellulose. Differential scanning calorimetry and thermogravimetric analyses showed higher temperature shifting of the decomposition peak, which indicated improved thermal stability of the ScCO2-treated celluloses. Additionally, a correlation test revealed that thermal stability of cellulose increased with the pressure of ScCO2.
Heliyon
In this study, a micro-encapsulated phase change material (PCM) was composed of sugarcane wax−Al2... more In this study, a micro-encapsulated phase change material (PCM) was composed of sugarcane wax−Al2O3composite as the core material and gelatin−gum Arabic as the polymer shell materials prepared by complex coacervation. The thermal behavior of solar panels integrated with this encapsulated PCM (EPCM) was investigated. The heat storage-dissipation performance and thermal stability of the sugarcane wax−based composite PCM layer with the heat capacity of 2.86 J/g·°C was influenced by its thickness. Increasing the composite PCM layer thickness from 4 mm to 7 mm could lower the module's front-facing glass temperature by 4% resulting in enhanced the photovoltaic power generation by 12% at the peak, because of the temperature storage ability of the composite PCM. Moreover, the thermal conductivity of the microencapsulated sugarcane wax was calculated using a steady-state one-dimensional energy balance equation. The thermal conductivities estimated across the composite PCM layer depth were found to be temperature dependent. A nonlinear regression of the power law thermal conductivity model gave a good agreement with the observed EPCM-surface temperatures.
Chemical Engineering Science
Abstract A diffusion-limited shrinking spherical particle model was developed to describe cellulo... more Abstract A diffusion-limited shrinking spherical particle model was developed to describe cellulose dissolution in carbon dioxide switchable system (CO 2 -SWS) by assuming an instantaneous reaction of the CO 2 -SWS on the cellulose surface. CO 2 , the main precursor of the SWS, was mixed with 1,8-diazabicyclo [5.4.0] undec-7-ene, ethylene glycol and dimethyl sulfoxide under various operating pressures ( P ) and temperatures ( T ) to yield a CO 2 switchable ionic liquid for cellulose dissolution. As dissolution proceeded, the cellulose particle radius decreased because of the disappearance of cellulose. The model–predicted diffusion coefficient ( D ), completed dissolution time ( τ ), and dissolution conversion ( X C ) were determined under various CO 2 -SWS operating conditions. The predicted τ and X C values were in good agreement with the observed results. The influence of the CO 2 -SWS operating conditions on the predicted numerical D , τ , and X C values were investigated using Spearman’s rho correlation. The results showed that the D values ranged from 10 −20 to 10 −17 m 2 s −1 for the CO 2 -SWS–cellulose system depending on the system conditions.
Journal of Environmental Chemical Engineering
Abstract This study aimed to investigate the adsorption isotherm and kinetics of polysaccharide-c... more Abstract This study aimed to investigate the adsorption isotherm and kinetics of polysaccharide-contaminated rice noodle wastewater onto superparamagnetic nanoparticles prepared by co-precipitation method. Three selected adsorption isotherms such as two-parameter equation (Langmuir and Freundlich) and three-parameter equation (Sips) and two non-linear kinetic models such as pseudo-first and pseudo-second kinetics were analyzed the adsorption data as a function of initial polysaccharide concentration range of 7000 to 8000 mg L−1. The nanoadsorbents removal efficiency of the polysaccharide was about 60% resulting in the COD reduction ranging from 29 to 42%. In comparison of estimated coefficient of determination (R2) using the linear method, the Freundlich showed higher value of R2 (0.98) than that of Langmuir isotherm. The equilibrium was best described by nonlinear Freundlich model among three isotherms, which gained the smallest χ2 value of 0.0297 while the adsorption process followed the pseudo-first order rate expression. Moreover, the nanoadsorbent dose had a direct effect on adsorption capacity while it had an adverse effect on the polysaccharide removal percentage. The prepared nanoadsorbents effectively removed high polysaccharide contents from rice noodle wastewater with moderate adsorption capacity.
The Journal of Supercritical Fluids
Abstract High-pressure carbon dioxide switchable solution with 1,8-diazabicyclo [5.4.0] undec-7-e... more Abstract High-pressure carbon dioxide switchable solution with 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) and ethylene glycol (EG) was applied for a dissolution and modification of cellulose derived from a cassava pulp waste. The switchable solution of DBU and EG were formed by adding carbon dioxide under a pressure range of 0.1–10.0 MPa and a temperature range of 298 and 333 K. The cellulose was dissolved into the CO2 switchable system at a pressure of 0.1 and 5.8 MPa and a temperature of 313 K. The precipitates of bicarbonate salt of reaction between DBU and carbon dioxide were observed in the switchable solution at the higher pressures and lower temperatures. The cellulose was also modified in the switchable solution with the ionized DBU, EG and carbon dioxide as analyzed by Fourier transform infrared spectroscopy. The modified cellulose was then utilized for the fabrication of the transparent film.
Kmitl Science and Technology Journal, Dec 16, 2014
The purpose of this study was to investigate the maximum annual revenue of regeneration process o... more The purpose of this study was to investigate the maximum annual revenue of regeneration process of spent activated carbon obtained from petrochemical industries, economic feasibility of the project, and the sensitivity analysis of parameters in optimization model. The regeneration process mainly arises from the direct sales of regenerated spent activated carbon and the purchase of fresh activated carbon for nonregenerable activated carbon. The maximum revenue of regeneration process of 24,951,673 baht per annum was used to estimate economic indicators. The values of ROI, NPV, and SPP were 15.20%, 90,233,640.98 baht, and 6.58 years, respectively. It was suggested a profitable regeneration plant. Moreover, amongst these three parameters the selling price of activated carbon was the most sensitive while the variable cost of regeneration process was the least sensitive to the NPV.
Bioprocess Biosyst Eng, 2007
Chiang Mai Journal of Science
Domestic waste activated sludge (WAS) produced from wastewater treatment process, non hazardous o... more Domestic waste activated sludge (WAS) produced from wastewater treatment process, non hazardous organic waste can reach up to 550,000 ton/y by 2012. For instance, poultry slaughter house and food processing plant generates lots of sludge waste 20,000 ton per year. To minimize the sludge waste disposal and to further transform organic matter into biogas, sludge anaerobic digestion is one of the most potential treatment processes. This study aimed to accelerate hydrolysis period by microwave-assisted pretreatment for improvement of biogas production from the WAS. Effect of mixing ratios between primary and anaerobic sludge, temperature and vacuum degree using microwave (MW) irradiation on biogas production improvement were studied in anaerobic batch reactors under mesophilic condition for 25 days. Experimental results showed that vacuum MW pretreatment at 65 o C and sludge mixture ratio of primary to secondary sludge at 60:40 was the most suitable condition for biogas production. The average methane yield was achieved 5,256 g CH 4 /kg dried solid and 91% CH 4 content which was about 1.3-fold higher than non-MW pretreatment. The accelerated hydrolysis of organic matters in WAS was hydrolyzed 3-fold faster than non-MW pretreatment. In comparisons between MW and non-MW pretreating experiments, average %COD removal, %glucose consumption and %VS production rate during hydrolysis period were decreased by 25.6%, 47.5% and 82.27%, respectively. A vacuum degree of MW thermal pretreatment had a direct effect on the mesophilic anaerobic biodegradability of WAS by damaging activated sludge floc structures and cell membranes as indicated by the solubilization of particulate CODs, glucose concentration and volatile solid amount.
Optimal feed rate profiles for fed-batch culture in penicillin production
Advanced Materials Research, 2014
Electrical energy generating from power plant is transmitted to electrical substations via high-v... more Electrical energy generating from power plant is transmitted to electrical substations via high-voltage transmission lines. After a certain period time of use, the transmission line is required for maintenance such as insulator replacement. To avoid power interruption during insulator replacement, a corrective maintenance, hot line maintenance, is performed. This research focused on the hot line insulator replacement of 230 kV Bangsapan-Chumporn and 230 kV Chumporn-Suratthani transmission lines transferring power between southern and central regions of Thailand. The maintenance of 230 kV double suspension string for two bundles with arcing horn required developed C.B.T. hot end yoke tool to enhance stability and availability of electrical energy during hot line insulator replacement. C.B.T was named by the initial letter of the name of Chumporn Bandon and Takuapa transmission lines under authorization of the maintenance section in responsible maintaining service of transmission line...
Energy Procedia, 2014
This study aimed to evaluate the optimal proportions of two forms of feedstocks such as cassava r... more This study aimed to evaluate the optimal proportions of two forms of feedstocks such as cassava roots and chips to minimize total cost of 340,000 liter/day ethanol production capacity by solving a linear programming problem. The time period for the optimization problem was based on 12 months in a year. There were four studied case scenarios as follows: (i) base case for interchangeable ethanol production process from two different feedstocks; (ii) modified based case for non-interchangeable monthly production process (iii) no limitation of feedstock supply for demand of ethanol manufactured in non-interchangeable production process; and (iv) inventory cost reduction scenario without maintaining minimum inventory during the time period of sufficient feedstock supply. The optimal result showed that cassava roots were first selected for their availability and then cassava chips were selected to satisfy monthly demand of ethanol due to threefold higher ethanol processing cost of cassava chips as feedstock. Amongst the first three cases with minimum inventory for each month, the case of unlimited feedstock supply (scenario iii) yielded the minimum total cost. However, the optimal total ethanol production cost of scenario (iv) without minimum inventory required during seasons of harvesting (November-April) and planting (May and October) was 5% lower than that of scenario (ii).
Korean Journal of Chemical Engineering, 2008
A modified Markov Chain Monte Carlo (MCMC) searching procedure was developed to search for an opt... more A modified Markov Chain Monte Carlo (MCMC) searching procedure was developed to search for an optimal set of decision variables and optimal feed rate trajectories for recombinant α-amylase expression by Bacillus subtilis ATCC 6051a. The bacterium also synthesizes proteases as undesirable products in fed-batch culture that need to be minimized. To maximize α-amylase productivity, a 14th-order fed-batch model was optimized by integrating Pontryagin's maximum principle with the Luedeking-Piret equation. The number of iterations and simulations of the proposed searching procedure were statistically examined for accuracy and acceptability of the results. It can be concluded that the proposed searching procedure increased the parameter selection opportunity near the tail ends of redefined triangular distribution. By applying a modified MCMC searching procedure with 1,500 iterations, the predicted αamylase productivity was improved by 18% in comparison with near-optimum experimental results. This productivity was 3.5% higher than predicted by conventional MCMC optimization.
Journal of Food Processing and …
Department of Chemical Engineering Thammasat University, (Rangsit campus), 99 Moo 18, Phahon Yoth... more Department of Chemical Engineering Thammasat University, (Rangsit campus), 99 Moo 18, Phahon Yothin Road, Pathumtani 12120 Thailand ... 1Corresponding author. TEL: +66-(2)-564 -3001∼9 ext. 3121; FAX: +66-(2)-564-3001∼9 ext. 3040; EMAIL: [email protected]
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Papers by Wanwisa Skolpap