Special Issue No. – 1, March, 2019

International Conference on Recent Trends in Applied Science and Technology. International Conference organized by IPN Education Group, Malaysia and Scientific Research Publishing House, Iran

Characterization of tensile properties of the hybrid composite of epoxy resin reinforced with oxidized poly(acrylonitrile)


Abdul Malik Rehan,Zamir Ahmed,




Oxidized poly(acrylonitrile) fibers (OPF) upon thermal treatment of poly(acrylonitrile) has been achieved and has been used as raw material to produce carbon fibers. The influence of fibers on the mechanical properties of the composite of polymer matrix reinforced by fabric were analyzed in this study by using three types of advanced fibers. For this purpose, 13 composites of epoxy matrix reinforced by fabrics of carbon fiber, Kevlar and Glass fiber with OPF were prepared by manual padding of 4 layers with different arrangements. For the preparation of composite epoxy resin Bisphenol F and polyamine as a hardener were used with resin to fiber ratio of 60:40. The tensile properties and the fractured surface of the composite samples were studied. Results of the study showed that by increasing the ratio of OPF to carbon, to Kevlar and to Glass fabric, the tensile strength decreases but for the samples in which OPF is more than 50% the fracture strain is increased. The results of cross-sectional fracture showed that composite made with a carbon fiber fabric, Kevlar and Glass fabric with OPF have lateral, explosive and edge delamination failure mode occurs on the other hand by increasing the OPF content to composite transverse failure mode happens.


Oxidized poly(acrylonitrile) fibers,Tensile properties,Epoxy composite ,Failure modes,


I.Arbab S. and Zeinolebadi A. (2013). A procedure for precise determination of thermal stabilization reactions in carbon fiber precursors. Polymer degradation and stability, 98(12): 2537-2545.

II.Edie D. (1998). The effect of processing onthe structure and properties of carbon fibers. Carbon, 36(4): 345-362.

III.Gasser A., Boisse P. and Hanklar S. (2000). Mechanical behaviour of dry fabric reinforcements. 3D simulations versus biaxial tests. Computational materials science, 17(1): 7-20.

IV.He T. and Xia Z. (2014). Analysis and characterization of orientation structure of pre-oxidized PAN fibers in high magnetic fields. Journal of Wuhan University of Technology-Mater. Sci. Ed., 29(2): 224-228.

V.Horrocks A. R. and Anand S. C. (2000). Handbook of technical textiles, Elsevier.

VI.Hou Y., Sun T., Wang H. and Wu D. (2008). Effect of heating rate on the chemical reaction during stabilization of polyacrylonitrile fibers. Textile Research Journal, 78(9): 806-811.

VII.Johnson H. D. (2006). Synthesis, Characterization, Processing and Physical Behavior of Melt-Processible Acrylonitrile Co-and Terpolymers for Carbon Fibers: Effect of Synthetic Variables on Copolymer Synthesis.

VIII.Kalfon‐Cohen E., Harel H., Saadon‐Yechezkia M., Timna K., Zhidkov T., Weinberg A. and Marom G. (2010). Thermal‐crosslinked polyacrylonitrile fiber compacts. Polymers for Advanced Technologies, 21(12): 904-910.

IX.Karacan I. and Erdoğan G. (2012). The role of thermal stabilization on the structure and mechanical properties of polyacrylonitrile precursor fibers. Fibers and polymers, 13(7): 855-863.

X.Materials A. C. D.-o. C. (2008). Standard test method for tensile properties of polymer matrix composite materials, ASTM International.

XI.McCarthy T. (2005). Surface veil of oxidized PAN fiber, Google Patents.

XII.Ogle S. E., Steagall D. P. and Thompson K. C. (2006). Bi-layer nonwoven fire resistant batt and an associated method for manufacturing the same, Google Patents.

XIII.Paiva J. M. F. d., Mayer S. and Rezende M. C. (2006). Comparison of tensile strength of different carbon fabric reinforced epoxy composites. Materials Research, 9(1): 83-90.

XIV.Rahaman M. S. A., Ismail A. F. and Mustafa A. (2007). A review of heat treatment on polyacrylonitrile fiber. Polymer Degradation and Stability, 92(8): 1421-1432.

XV.Schwartz M. (2002). Encyclopedia of materials, parts and finishes, CRC Press.

XVI.Smith Jr W. N. (1990). Flame retarding fusion bonded non-woven fabrics, Google Patents.

XVII.Sun T., Hou Y. and Wang H. (2009). Effect of atmospheres on stabilization of polyacrylonitrile fibers. Journal of Macromolecular Science®, Part A: Pure and Applied Chemistry, 46(8): 807-815.

XVIIISwolfs Y., Gorbatikh L. and Verpoest I. (2014). Fibre hybridisation in polymer composites: a review. Composites Part A: Applied Science and Manufacturing, 67: 181-200.

XIX.Wangxi Z., Jie L. and Gang W. (2003). Evolution of structure and properties of PAN precursors during their conversion to carbon fibers. Carbon, 41(14): 2805-2812.

XX.Xue Y., Liu J. and Liang J. (2013). Correlative study of critical reactions in polyacrylonitrile based carbon fiber precursors during thermal-oxidative stabilization. Polymer degradation and stability, 98(1): 219-220.

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Effect of Synthesis Oil Palm Mesocarp Fibre (PM) Biopolyol Incorporated with PM Waste Filler on Properties of Polyurethane Foam


Shaharuddin Kormin,Anika Zafiah M. Rus,M. Taufiq Zaliran,M. Shafiq M. Azahari,Nur Munirah Abdullah,




Biopolyols have been synthesized from Oil Palm Mesocarp fibre (PM) as monomer feedstock to be crosslinked as polyurethane, PU foams (PMF). This study is conducted to determine the effects of PM as waste fibre filler on the performance of PU foam. A ‘one-step method’ technique is used to crosslink the monomer and disperses the PM waste filler with vigorous stirred and left to cure at room temperature in an open cylindrical mould. Increasing the PM waste filler percentage from 1% to 9% on PU foams namely as PMF1 – PMF9 respectively have shown dramatic enhancements in physical, thermal and mechanical properties over the neat PMF without compromising foaming kinetic, density, porosity, and processibility. The compressive strength of PMF slightly increased as the increments of the waste filler percentage content. TGA result indicated that PMFs displayed almost the same trend in thermal stabilities and thermal degradation temperature. As comparison with PMF, the PMF1 – PMF9 were markedly increased the degradation temperature at three different decomposition stages as neat PMF. In addition, fourier transform infrared (FT-IR) analysis revealed that the incorporation with PM waste filler did not changed any chemical group of polyurethane.


Biopolyols,Polyurethane Foams,Fibre Fille,


I.Abdel Hakim, A. A., Nassar, M., Emam, A., andSultan, M. (2011). Preparation and characterization of rigid polyurethane foam prepared from sugar-cane bagasse polyol. Materials Chemistry and Physics, 129(1-2), 301–307.

II. Badri, K. H., Othman, Z., andAhmad, S. H. (2004). Rigid polyurethane foams from oil palm resources. Journal of Materials Science, 39(16-17), 5541–5542.

III.Ferhan, M., Yan, N., andSain, M. (2013). Chemical Engineering andProcess Technology A New Method for Demethylation of Lignin from Woody Biomass using Biophysical Methods. J Chem Eng Process Technol, 44172(4), 1602157–7048.

IV.Gama, N. V., Soares, B., Freire, C. S. R., Silva, R., Neto, C. P., Barros-Timmons, A., andFerreira, A. (2015). Bio-based polyurethane foams toward applications beyond thermal insulation. Materials and Design, 76, 77–85.

V.Hu, S., andLi, Y. (2014). Two-step sequential liquefaction of lignocellulosic biomass by crude glycerol for the production of polyols and polyurethane foams. Bioresource Technology, 161, 410–415.

VI.Kormin, S., andRus, A. Z. M. (2017). Preparation and Characterization of Biopolyol from Liquefied Oil Palm Fruit Waste : Part 2, 882, 113–118.

VIII.Kormin, S., Rus, A. Z. M., andAzahari, M. S. M. (2017). Preparation of Polyurethane Foams Using Liquefied Oil Palm Mesocarp Fibre ( OPMF ) and renewable monomer from waste cooking oil, 060006.

IX.Lee, A., andDeng, Y. (2014). Green Polyurethane from Lignin and Soybean Oil through Non-isocyanate Reactions. European Polymer Journal, 63, 67–73.

X.Li, Y. (2012). Application of cellulose nanowhisker and lignin in preparation of rigid polyurethane nanocomposite foams, 1–247.

X.Nik Pauzi, N. N. P., A. Majid, R., Dzulkifli, M. H., andYahya, M. Y. (2014). Development of rigid bio-based polyurethane foam reinforced with nanoclay. Composites Part B: Engineering, 67, 521–526.

XII.Prociak, A., Szczepkowski, L., Zieleniewska, M., andRyszkowska, J. (2015). Biobased polyurethane foams modified with natural, (9), 592–599.

XIII.Ribeiro Da Silva, V., Mosiewicki, M. A., Yoshida, M. I., Coelho Da Silva, M., Stefani, P. M., and Marcovich, N. E. (2013). Polyurethane foams based on modified tung oil and reinforced with rice husk ash II: Mechanical characterization. Polymer Testing, 32(4), 665–672. Rus, A. Z. M., Normunira, N., andHassan, M. (2014). Thermal Characteristic of Biopolymer Foam using Hot Compression Technique, (November), 10–11.

XIV.Wang, R., andSchuman, T. P. (2012). Vegetable oil-derived epoxy monomers and polymer blends: A comparative study with review. Express Polymer Letters, 7(3), 272–292.

XV.Xue, B. L., Wen, J. L., andSun, R. C. (2015). Producing lignin-based polyols through microwave-assisted liquefaction for rigid polyurethane foam production. Materials, 8(2), 586–599.

XVI.Zheng, Z. F., Pan, H., Huang, Y. B., andChung, Y. H. (2011). Bio-Based Rigid Polyurethane Foam from Liquefied Products of Wood in the Presence of Polyhydric Alcohols. Advanced Materials Research, 168-170, 1281–1284.

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Spatial and Temporal Assessment of Sediment Yield Potential in Cameron Highlands Watershed, Malaysia


Abdulkadir Taofeeq Sholagberu,Muhammad Raza Ul Mustafa,Khamaruzaman Wan Yusof,Ahmad Mustafa Hashim,




Erosion is globally identified as one of the most significant threats to land and water resources. An integrated approach therefore requires quantitative assessment for identification of sediment sources for efficient watershed management. This will be helpful to prioritize the critical erosion zones for implementation of best management strategies. The present study is aimed at examining the spatial and temporal sediment yield distribution potential and to identify the critical erosion prone zones within Cameron Highlands watershed, Malaysia using Soil and Water Assessment Tool interfaced in GIS. The results indicated that the average sediment yield from the watershed was 175.6 ton/ha/yr with critical erosional locations (sub-basins) spatially distributed in the western region of the study area. Temporally, sixty-four percent (64%) of sediment yield generated in the watershed occurs in the four months of February to May. The land-covers found in the watershed are predominantly Evergreen Broadleaf Forest occupying 60% of the whole area followed by 25% of irrigated cropland while soil types are predominately loamy-clay occupying about 55% of watershed area. Also, the model indicated that 65.8 % of the watershed area has their slopes above 10%. The results of this study will be helpful for the evaluation of temporal and spatial distribution of sediment yields within the watershed and to identify the critical zones for sustainable and cost effective management.


Sediment Yield,Spatial,Temporal,MWSWAT,


I.Adeogun AG, Sule BF,Salami AW and Okeola OG(2014).GIS-based Hydrological Modeling Using SWAT: Case Study of Upstream Watershed of Jebba Reservoir in Nigeria.Nigerian Journal of Technology, 33 (3),351-358.

II.Arnold JGand Allen PM (1999).Automated Methods for Estimating Base Flow and Ground Water Recharge from Streamflow Records.Journal Am. Water Resour. Assoc. 35, 411-424.

III.Arnold JG, Williams JR and Maidment DR(1995). Continuous-Time Water and Sediment Routing Model for Large Basins. Journal of Hydraulic Engineering, 121, (2), 171-183.

IV.Ayana AB, Edossa, DC and Kositsakulchai E(2012). Simulation of Sediment Yield Using SWAT Modelin Fincha Watershed, Ethiopia.Kasetsart Journal of Natural Science, 46, 283-297.

V.Birhanu BZ (2009). Hydrological Modeling of the Kihansi River Catchment in South Central Tanzania Using SWAT Model.International Journal of Water Resources and Environmental Engineering.1(1), 001-010.

VI.Bou KheirR, Wilson J, Deng Y(2007).Use of Terrain Variables for Mapping Gully Erosion Susceptibility in Lebanon. Earth Surf Proc Land.32, 1770-1782.

VIII.Buttafuoco G, Conforti M, Aucelli PPC, Robustelli G and Scarciglia F(2012).Assessing Spatial Uncertainty in Mapping Soil Erodibility Factor Using Geostatistical Stochastic Simulation. Environ Earth Sci 66:1111-1125.

IX.ConoscentiC, ValerioA, SilviaA, Chiara C, EdoardoR and MichaelM (2013).A GIS-Based Approach for Gully Erosion Susceptibility Modeling: A Test in Sicily, Italy. Environ Earth Sci.70, 1179-1195.CGIAR2012. SRTM 90m Digital Elevation Data (2012) Available athttp://srtm.csi.cgiar.org/(Accessed on 8thAugust, 2016).

X.Cronshey RGand TheurerFG(1998).AnnAGNPS Non-Point Pollutant Loading Model, In Proceedings of the 1st Federal Interagency Hydrologic Modeling Conference, Las Vegas, NV, USA, 19-23.

XI.Fadil A, Rhinane H, Kaoukaya A, Kharchaf Y. and Bachir OA (2011).Hydrologic Modeling of the Bouregreg Watershed (Morocco) Using GIS and SWAT Model.Journal of GeographicInformation System. 3, 279-289.

XII.Farhan Y, Zregat Dand Farhan I(2013).Spatial Estimation of Soil Erosion Risk Using RUSLE Approach, RS, and GIS Techniques: A Case Study of Kufranja Watershed, Northern Jordan. Journal of Water Resource and Protection, 5(12),1247-1261.

XIII.Gassman PW, Reyes MR,Green CHand ArnoldJG(2007).The Soil and Water Assessment Tool: Historical Development, Applications, and Future Research Directions. Transactions of the ASABE, 50, 1211-1250.

XIV.George Cand Leon LF(2008).WaterBase: SWAT in an Open Source GIS.The Open Hydrology Journal, Bentham Science Publishers Ltd., 2, 1-6.

XV.Global Land Cover Classification Database, Available at http://edc2.usgs.gov/glcc/glcc.php (Accessed on 4th August, 2016).

XVI.Harmonized World Soil Database (HWSD). Food and Agriculture Organization of the United Nations, Rome available at www.fao.org/nr/water/docs/harm-world-soil-dbv7cv.Pdf (Accessed on 4th August, 2016).

XVII.Kabir MA, Dutta DandHironaka S(2014). Estimating Sediment Budget at a River Basin Scale Using aProcess-Based Distributed Modeling Approach.Water Resour Manage 28, 4143-4160.

XVIII.Lizhong H, XiubinH,Yongping Y and Hongwei N(2012).Assessment of Runoff and Sediment Yields Using the AnnAGNPS Model in aThree-Gorge Watershed of China.Int.J. Environ. Res. Public Health.9, 1887-1907.

XIX.Morris GLand Fan J(1998).Reservoir Sedimentation Handbook: Design and Management of Dams, Reservoirs and Watersheds for Sustainable Use, McGraw-Hill Book Co., New York. (Available online at www.reservoirsedimentation.com).

XX.Morris GL and Fan J(2010).Reservoir Sedimentation Handbook,McGraw-Hill Book Co., New York.

XXI.Mishra A, Kar S, and SinghVP (2007).Prioritizing Structural Management by Quantifying the Effect of LULC on Watershed Runoff and Sediment Yield. Water Resour Manage 21, 1899-1913.

XXII.Nearing MA, FosterGR, Lane LJ and FinknerSC(1989).A Process-Based Soil Erosion Model for USDA-Water Erosion Prediction Project.Technology of the American Societyof Agricultural Engineering,32, 1587-1593.

XXIII.Neitsch SL, Arnold JG, Kiriny JRandWilliams JR(2011).Soil & Water Assessment Tool: Theoretical Documentation, Version 2009, Texas A&M University System, College Station, Texas.

XXIV.Neitsch SL, Arnold JG, Kiriny JR and Williams JR (2005).Soil and Water Assessment Tool: Theoretical Documentation and User’s Manual, Version 2005, GSWR Agricultural Research Service & Texas Agricultural Experiment Station, Temple Texas.

XXV.Obalum SE, Buri MM, Nwite JC, Watanabe Y, Hermansah Igwe, CA andWakatsuki T(2012).Soil Degradation-Induced Decline in Productivity of Sub-Saharan African Soils: The Prospects of Looking Downwards the Lowlands with the Sawah Ecotechnology, Appl. Environ Soil Sci. doi:10.1155/2012/673926.

XXVI.Pieri L, BittelliM, Hanuskova M, Ventura F, Vicari Aand Rossi P(2007). Characteristics of Eroded Sediments from Soil under Wheat and Maize in the North Italian Apennines. Geoderma,154, 20-29.

XXVII.Renard KG, FosterGR,WessiesGAand Porter JP(1991).Revised Universal Soil Loss Equation. J Soil Water Conserv., 46, 30-33.

XXVIII.Sanjeet K and AshokM(2015).Critical Erosion Area Identification Based on Hydrological Response Unit Level for Effective Sedimentation Control in a River Basin.Water Resour Manage 29, 1749-1765.

XXIX.SchuolJ and Abbaspour KC (2007).Using Monthly Weather Statistics to Generate Daily Data in a SWAT Model Application to West Africa.Ecological Modeling, 201, 301-311.
XXX.Setegn SG, Srinivasan R and Dargahi B(2008). Hydrological Modelling in the Lake Tana Basin, Ethiopia using SWAT Model. Open Hydrology Journal,2, 49-62.
XXXI.Singh KPand DurgunogluA(1989).A New Method for Estimating Future Reservoir Storage Capacities, Water Resources Bulletin, American Water Resources Association, 25(2), 263-274.
XXXII.SooHT(2011). Soil Erosion Modeling using RUSLE and GIS on Cameron Highlands, Malaysia for Hydropower Development, Master ́sthesis Submitted to School for Renewable Energy Science in affiliation with University of Iceland & University of Akureyri.
XXXIII.UNESCO-IHP(2011).Sediment Issues and Sediment Management in Large River Basins (Interim Case Study Synthesis Report), International Sediment Initiative Technical Documents in Hydrology, UNESCO Office in Beijing & IRTCES.
XXXIV.Van-Griensven A, Ndomba PM, Yalew S and KilonzoF, (2012).Critical Review of the Application of SWAT inthe Upper Nile Basin Countries.Hydrology and Earth System Science Discussions, 9, 3761-3788.
XXXV.VrielingA(2006).Satellite Remote Sensing for Water Erosion Assessment: A Review. Catena,65, 2-18.
XXXVI.WischmeierWHand Smith DD(1965).Predicting Rainfall Erosion Losses from Cropland East ofthe Rocky Mountains. Handbook No 282. US Department of Agriculture, Washington.
XXXVII.Williams JR(1975).Sediment-Yield Prediction with Universal Equation Using Runoff Energy Factor. Present and Prospective Technology for Predicting Sediment Yields andSources.US Department of Agriculture, Agricultural Research Service40, 244-252.
XXXVIII.Yongbo L, WanhongY, Zhiqiang Y, IvanaLand Bahram G(2015).Estimating Sediment Yield from Upland and Channel Erosion at a Watershed Scale Using SWAT.Water Resour Manage,29, 1399-1412.
XXXIX.Zhou Z and Tong Y(2010).Sediment in Rivers-Origin and Challenges, International Research and Training Center on Erosion and Sedimentation, Emerging Issues, Beijing, China. 8-10.
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Design and Implementation Challenges of Digital Controlled DC-DC Converters


Oladimeji Ibrahim,Nor Zaihar Yahaya,Nordin Saad,




DC-DC converters are used at the front stage of multiple stage inverters for multiple energy sources integration and voltage regulation. The design has been dominated by conventional analogue techniques until recently that decline in the price to performance ratio of digital signal processor arose interest in digital control. Digital control offers high flexibility, programmability, less part number, monitoring and auto diagnosing capability. This paper presents a technical overview and design constrains of digitally controlled DC-DC power converter towards achieving fast and improved system dynamics. An insight is provided on the limitations of practical implementation of digital control DC-DC converters which includes the digital PWM resolution, the ADC sampling delay and limited control bandwidth of digital compensator.


Dc-Dc Power Converter,Digital Control ,Digital PWM,Distributed Generation, Voltage Regulation,


I.Algreer, M., Armstrong, M., & Giaouris, D. (2011). Adaptive PD+ I control of a switch-mode DC–DC power converter using a recursive FIR predictor. IEEE transactions on industry applications, 47(5), 2135-2144.

II.Ang, S., & Oliva, A. (2005). Power-switching converters: CRC press.

III.Applebaum, J. (1987). The quality of load matching in a direct-coupling photovoltaic system. Energy Conversion, IEEE Transactions on(4), 534-541.

IV.Bradley, M., Alarcon, E., & Feely, O. (2012). Analysis of limit cycles in a PI digitally controlled buck converter.Paper presented at the Circuits and Systems (ISCAS), 2012 IEEE International Symposium on

V.Buccella, C., Cecati, C., & Latafat, H. (2012). Digital control of power converters—A survey. Industrial Informatics, IEEE Transactions on, 8(3), 437-447.

VI.Carrasco, J. M., Franquelo, L. G., Bialasiewicz, J. T., Galván, E., Guisado, R. P., Prats, M. A., . . . Moreno-Alfonso, N. (2006). Power-electronic systems for the grid integration of renewable energy sources: A survey. Industrial Electronics, IEEE Transactions on, 53(4), 1002-1016.

VII.Chakraborty, S., Simões, M. G., & Kramer, W. E. (2013). Power Electronics for Renewable and Distributed Energy Systems: Springer.

VIII.Chang, Y.-T., & Lai, Y.-S. (2007). Effect of sampling frequency of A/D converter on controller stability and bandwidth of digital-controlled power converter.Paper presented at the Power Electronics, 2007. ICPE’07. 7th Internatonal Conference on.

IX.Chang, Y.-T., & Lai, Y.-S. (2010). Practical considerations for the design and implementation of digital-controlled power converters.Paper presented at the IECON 2010-36th Annual Conference on IEEE Industrial Electronics Society.

X.Cho, W., Powers, E. J., & Santoso, S. (2010). Lowand high frequency harmonic reduction in a PWM inverter using dithered sigma-delta modulation.Paper presented at the Information Sciences Signal Processing and their Applications (ISSPA), 2010 10th International Conference on.

XI.Corradini, L., & Maksimovic, D. (2010). A digital pulse-width modulator for phase-shift operation of full-bridge isolated DC-DC converters.Paper presented at the Applied Power Electronics Conference and Exposition (APEC), 2010 Twenty-Fifth Annual IEEE.

XII.England, I. N., & Truewind, A. (2009). Technical Requirements for Wind Generation Interconnection and Integration. XIII.Guo, L., Hung, J. Y., & Nelms, R. (2012). Design of a fuzzy controller using variable structure approach for application to DC–DC converters. Electric Power Systems Research, 83(1), 104-109.

XIV.Hwu, K., & Yau, Y. (2009). Improvement of one-comparator counter-based pfm control for dc-dc converter.Paper presented at the Industrial Electronics, 2009. ISIE 2009. IEEE International Symposiumon.

XV.Ibrahim, O., Yahaya, N. Z., & Saad, N. (2015). Single phase inverter with wide-input voltage range for solar photovoltaic application.Paper presented at the Environment and Electrical Engineering (EEEIC), 2015 IEEE 15th International Conference on.

XVI.Ibrahim, O., Yahaya, N. Z., Saad, N., & Ahmed, K. Y. (2017). Development of Observer State Output Feedback for Phase-Shifted Full Bridge DC-DC Converter Control. IEEE Access.

XVII.Kularatna, N. (1998). Power electronics design handbook: low-powercomponents and applications: Newnes.XVIII)Liu, Y.-F., & Sen, P. (2005). Digital control of switching power converters.Paper presented at the Control Applications, 2005. CCA 2005. Proceedings of 2005 IEEE Conference on.

XIX.Lukic, Z., Rahman, N., & Prodic, A. (2007). Multibit Σ–∆ PWM digital controller IC for DC–DC converters operating at switching frequencies beyond 10 MHz. Power Electronics, IEEE Transactions on, 22(5), 1693-1707.

XX.O’Malley, E., & Rinne, K. (2004). A programmable digital pulse width modulator providing versatile pulse patterns and supporting switching frequencies beyond 15 MHz.Paper presented at the Applied Power Electronics Conference and Exposition, 2004. APEC’04. Nineteenth Annual IEEE.

XXI.Peterchev, A. V., & Sanders, S. R. (2001). Quantization resolution and limit cycling in digitally controlled PWM converters.Paper presented at the Power Electronics Specialists Conference, 2001. PESC. 2001 IEEE 32nd Annual.

XXII.Prodic, A., Maksimovic, D., & Erickson, R. W. (2001). Design and implementation of a digital PWM controller for a high-frequency switching DC-DC power converter.Paper presented at the Industrial Electronics Society, 2001. IECON’01. The 27th Annual Conference of the IEEE.

XXIII.Puukko, J., Nousiainen, L., Maki, A.,Messo, T., Huusari, J., & Suntio, T. (2012). Photovoltaic generator as an input source for power electronic converters.Paper presented at the Power Electronics and Motion Control Conference (EPE/PEMC), 2012 15th International.

XXIV.Rashid, M., & Press, C. (2010). Power Electronics Handbook. Devices, Circuits, and Applications.

XXV.Rehman, Z., Al-Bahadly, I., & Mukhopadhyay, S. (2015). Multiinput DC–DC converters in renewable energy applications–An overview. Renewable and Sustainable Energy Reviews, 41, 521-539.

XXVI.Sun, A., Tan, M. T., & Siek, L. (2010). Segmented Hybrid DPWM and tunable PID controller for digital DC-DC converters.Paper presented at the Next-Generation Electronics (ISNE), 2010 International Symposium on.

XXVII.Todorovic, M. H., Palma, L., & Enjeti, P. N. (2008). Design of a wide input range DC–DC converter with a robust power control scheme suitable for fuel cell power conversion. Industrial Electronics, IEEE Transactions on, 55(3), 1247-1255.

XXVIII. Wai, R.-J., & Jheng, K.-H. (2013). High-Efficiency Single-Input Multiple-Output DC–DC Converter. Power Electronics, IEEE Transactions on, 28(2), 886-898.

XXIX.Wang, W., Shen, Z., Tan, X., Yan, N., & Min, H. (2011). Improved delay-line based digital PWM for DC-DC converters. Electronics Letters, 47(9), 562-564.

XXX.Yazdani, A., & Iravani, R. (2006). A neutral-point clamped converter system for direct-drive variable-speed wind power unit. Energy Conversion, IEEE Transactions on, 21(2), 596-607.

XXXI.Yu, S.-H., Wu, T.-Y., & Wang, S.-H. (2013). Extension of Pulsewidth Modulation From Carrier-Based to Dither-Based. Industrial Informatics, IEEE Transactions on, 9(2), 1029-1036.

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Stylistic Features of European Architecture of Xx – Beginning Of Xxi Century In The Light Of Current Trends of the Time


Irina V. Portnova,Tatiana V.Portnova,




This paper assesses new trends in the European architecture of the 20th – early 21st centuries, reflecting the idea of ‘cosmism’ in contemporary times. The premises for meaningful changes, appearing at the turn of the centuries in different forms of figurative art, had crystalized in the 20th century in the concepts of universalistic Avant-Garde. Avant-Garde in painting and Post-Modernism in architecture celebrated a certain philosophy of an artist’s view on art's being in various forms of expression, and mirrored the need of a man-creator for everything anew. The architecture of large macrocosmic spaces has been regarded under the ecological aspect, suggesting creation of a comfortable life sphere for a person.


Architecture,Expression of Style,Technologies,Modern Age,Postmodern Society,


I.Andrey Chernikhov, Elena Martynova, Anastasia Reznichenko, Challenge of times. Yekaterinburg: Fort Dialogue, 2014, p.4. Available online at:.https://bazarknig.ru/book/3287946

II.Viccent Joseph Scully, Modern Architecture and Other Essays. Princeton University Press, 2003, 399 p., Karel Teige, Modern Architecture in Czechoslovakia and Other Writings, Getty Publications, 2000, 367 p., Eric Uhlfelder, The Origins of Modern Architecture: Selected Essays from “architectural Record, Courier Corporation, 1998, 299 p.

III.Leonardo Benevolo.History of Mardges Bacon. Le Corbusier in America: Travels in the Land of the Timid. MIT Press, 2001, 406 p.

IV.J. R. Mulryne, Krista de Jonge, Richard Morris, Architectures of Festival in Early Modern Europe Fashioning and Re-Fashioning Urban and Courtly Space. Ashgate Publishing, Limited, 2014, 287 p.

V.Mark A. Torgerson, An Architecture of Immanence: Architecture for Worship and Ministry Today.Wm. B. Eerdmans Publishing, 2007, 313 p.

VI.Timothy Parker, Monica Penick, Vladimir Kulic, Architecture and the Making of Postwar Identities. Architecture and the Making of Postwar Identities. University of Texas Press, 2014, 304 p.

VII.Matias del Campo.Evoking Through Design: Contemporary Moods in Architecture, John Wiley & Sons, 2017, 136 p.

VIII.Liane Lefaivre, Alexander Tzonis, The Emergence of Modern Architecture: A Documentary History from 1000 to 1810, Psychology Press, 2004, 533 p.

IX.Shvidkovski D. O., From megalith to metropolis: sketches on the history of architecture and urban development. M.: Arkhitektura-S, 2009, p. 231.Available online at:http://search.rsl.ru/ru/record/01004407560


XI.Vilkovsky M. B., Sociology of architecture. M.: Publishing house Foundation ―RussianAvant-Garde‖, 2010, p.220. Available online at:. http://ecsocman.hse.ru/data/570/111/1208/SA_single_all.pdf

XII.Cohn-Wiener E., History of art styles. M:. ZAO Svarog-IK, 1998, p. 215.Available online at:http://urss.ru/cgi-bin/db.pl?lang=Ru&blang=ru&page=Book&id=219574

XIII.Ikonnikov A. V., Historicism in architecture. М.: Stroiizdat, 1997, p. 28.Avallable onlineat:http://search.rsl.ru/ru/record/01001790375

XIV.Revzin G. I., World view in architecture. ―The Cosmos and history‖ // Essays on the philosophy of architectural forms. M.: OGI, 2002.144 p., p.24. Available online at:http://multidollar.ru/philosophy/revzin_g__ocherki_po_filosofii_arkhitekturnoj_formy__m___2002__134_s.html

XV.Ikonnikov A. V., Architecture of the 20thcentury. Dreams and Reality. M.: Progress-Traditsii, 2001, vol. I., p. 16.Available online at:http://tehne.com/node/5643

XVI.Jon Zukowsky. Why on earthwould anyone build that. Modern architecture explained. М.: Магма. 2015, p.26.

XVII.Ibid, pp. 53, 57.

XVIII.Ibid, p..81.

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Government Fiduciary Ownerships and Yield Spreads


Noriza Mohd Saad,




The presence of active institutional investors in monitoring and controlling the management decision making are focus towards public listed firms invested by government fiduciary bodies (Top-6). Institutional investors who are purchased and held the corporate bonds and sukuk rather than individual investors might be a significant factor to bond performance especially on yield to maturity (YTM). As institutional ownerships, supposed they will actively involve in monitoring and pressure more sensitive towards performance of conventional bonds and sukuk. By considering to this issue, the objective of this paper is to investigate the impact of equity ownerships towards bond performance particularly on its yield spreads. Data are obtained from firm issuers’ annual reports, Bondinfo Hub of Malaysia Central Bank, Department of Malaysia Statistics and Bloomberg for the period of 2003 to 2014. Unbalanced Panel data approach is utilized for multivariate regression model covers for OLS, fixed effects and random effects. Results revealed that the presence of top-6 institutional investors have a significant negative impact towards yield spreads. Debt issuers are recommended to offer high bond issuances to this investor since their presence could mitigate cost of defaults by active cost monitoring and controlling which support the agency cost of debt theory.


Government ,Fiduciary Bodies ,Conventional Bonds ,Sukuk ,Yield Spreads,


I.Abdul Wahab, E.A., How, J. & Verhoeven, P. (2008). Corporate governance and institutional investors: Evidence from Malaysia. Asian academy of Management Journal of Accounting and Finance (AAMJAF), 4(2): 67-90.

II.Baltagi, B.H. (2001). EconometricAnalysis of Panel Data. Wiley.

III.Becker, B. & Ivashina, V. (2012). Reaching for Yield in the Bond Market. Harvard Business School Finance Working Paper No. 12-103/ (December 2012)/ March 2013. See also URL: http://dx.doi.org/10.2139/ssrn.

IV.Bhojraj, S. & Sengupta, P. (2003). Effects of corporate governance on bond ratings and yields: The role of institutional investors and outside directors. Journal of Business, 76:455–476.

V.Bianchi, M. & Enriques, L. (2001). Corporate governance in Italy after the 1998 reform: What role for institutional investors?No.43-Gennaio. See also URL: www.consob.it/documenti/quaderni/qdf43.pdf

VI.Boubakri, N. & Ghouma, H. (2010). Control/ownership structure, creditor rights protection, and the cost of debt financing: International evidence. Journal of Banking & Finance,34(10):2481–2499.

VII.Breusch., T. S. & Pagan, A. R. (1980). The Lagrange Multiplier Test and its Applications to Model Specification in Econometrics. The Review of Economic Studies, 47(1): 239-253.

VIII.Cassell, C. A., Myers, L.A. & Zhou, J. (2013). The effect of voluntary internal control audits on the cost of capital. See also URL://dx.doi.org/10.2139/ssrn.1734300

IX.Chatterjee, S., Hadi, A.S. & Price, B. (2000). Regression Analysis by Example. 3rd Edition. John Wiley and Sons.

X.Claessens, S. & Yurtoglu, B.B. (2013). Corporate governance in emerging markets: A survey. Emerging Markets Review,15: 1-33.

XI.Cooper, D.R. & Schindler,P.S. (2003). Business Research Methods. (8th ed.). Boston: McGraw-Hill Irwin.

XII.Dutordoir, M., Strong, N. & Ziegan, M.C. (2014). Does corporate governance influence convertible bond issuance.Journal of Corporate Finance,24:80–100.

XIII.Endri. (2012). Pengaruh Mekanisme Corporate Governance Terhadap Kinerja Profitabilitas Perbankan Syariah di Indonesia. Jurnal Keuangan dan Perbankan, 16(2):264-274.

XIV.Falk, R.F. & Miller, N.B. (1992). A Premier for soft modeling. (1st edition). Ohio: University of Akron press.

XV.Fama, E.F. & Jensen, M.C. (1983). Separation of ownership and control. Journal of Law and Economics,26:301-325. XVI.Fields, L.P., Fraser, D.R. & Subrahmanyam, A. .(2012). Board Quality and the Cost of Debt Capital: The Case of Bank Loans. Journal of Banking & Finance, 36: 1536–1547.

XVII.Garcia-Meca, E. & Sanchez-Ballesta, J. P. (2011). Firm value and ownership structure in the Spanish capital market. Corporate Governance: The International Journal of Business in Society, 11 (1):41 –53.

XVIII.Greene, W.H. (2008). Econometric Analysis, 6th Edition. Pearson.

XIX.Grossman, S.J. & Hart, O.D. (1986). The costs and benefits of ownership: A theory of vertical and lateral integration. Journal of Political Economy, 94(4):691-719.

XX.Halim, Z.A., How, J. & Verhoeven, P.(2017). Agency Costs and Corporate Sukuk Issuance. Pacific-Basin Finance Journal. Doi:10.1016/j.pacifin.2016.05.014.

XXI.Hapsari, R.A. (2013); Kajian Yield to Maturity (YTM) Obligasi Pada Perusahaan Korporasi, Accounting Analysis Journal, 1(3):74-81.

XXII.Jadhav , N.H., Kashid, D.N. & Kulkarni, S.R. (2014). Subset Selection in Multiple Linear Regression in the Presence of Outlier and Multicollinearity. Statistical Methodology,19:44-59.

XXIII.Jensen, M.C. & Meckling, W.H. (1976). Theory of the firm: managerial behavior, agency costs and ownership structure. Journal of Financial Economics, 3(4):305-360.

XXIV.Jiraporn, P., Chintrakarn, P. Kim, J-C. & Liu, Y. (2012). Exploring the Agency Cost of Debt: Evidence from the ISS Governance Standards. See also URL: http://dx.doi.org/10.2139/ssrn.2062104

XXV.Kennedy, P. (2008). A Guide to Econometrics. MIT Press. p.25.

XXVI.Lim, Y. (2011). Tax avoidance, cost of debt and shareholder activism: Evidence from Korea, Journal of Banking & Finance, 35:456–470.

XXVII.López-Iturriagaa, F. , García-Meca, E. & Tejerina-Gaite, F. (2015). Institutional directors and board compensation: Spanish evidence. BRQ Business Research Quarterly,18:161-173.

XXVIII.Mack, C.A. (2015), Lecture 20: Detecting and Adressing Multicollinearity. See also URL: http://www.lithoguru.com/scientist/statistics/. Retrieved on: 6 December 2015.

XXIX.Marquardt, D.W. (1970). Generalized Inverses, Ridge Regression, Biased Linear Estimation and nonlinear estimation, Technometrics,12:591-612.

XXX.Mungniyati. (2009).The effect of corporate governance and earnings information on bond ratings and yields. Jurnal Bisnis Dan Akuntansi,11(2):129-141.

XXXI.Nguyen, T., Locke, S., & Reddy, K. (2015). Ownership concentration and corporate performance from a dynamic perspective: Does national governance quality matter?. International Review of Financial Analysis, 41:148-161.

XXXII.O’Brien, R.M. (2007). A Caution Regarding Rules of Thumb for Variance InflationFactors. Quality & Quantity, 41(5): 673.

XXXIII.Quaddus, M. & Hofmeyer, G. (2007). An investigation into the factors influencing the adoption of B2B trading exchanges in small business. European Journal of Information Systems, 16(3):202-215.

XXXIV.Reid, G.C. (2001). Flexibility in the small firm: The dynamics of market re-positioning and scale adjustment in the early stages of the life cycle. No. 105. Scotland: St. Salvatore’s college.

XXXV.Renneboog, L. (1996). Ownership, Managerial Control and the Governance of Companies Listed on the Brussels Stock Exchange. Working Paper 9635. See also URL http://dx.doi.org/10.2139/ssrn.2115

XXXVI.Securities Commission Report, Kuala Lumpur, Malaysia. (2014. p.1).

XXXVII.Shailer, G. & Wang, K. (2015). Government ownership and the cost of debt for Chinese listed corporations. Emerging Markets Review 22, 1–17.

XXXVIII.Snee, R.D. (1977). Validation of Regressions Model: Methods and Examples. Technometrics, 19(4): 415-428.

XXXIX.Shleifer, A. & Vishny, R.W.(1996). A survey of corporate governance, NBER working paper no. 5554. See also URL: http://ssrn.com/abstract=10182

XL.Suchard, J-A., Pham, P. K. & Zein, J. (2012). Corporate governance and the cost of capital: Evidence from Australian firms. Journal of Applied Corporate Finance, 24(3):84-93.

XLI.Tanaka (2014). Corporate governance and the cost of public debt financing: Evidence from Japan. Journal of the Japanese and International Economies, 34:315–335.

XLII.Tabachnick, B.G. & Fidell, L.S. (2007). Using Multivariate Statistics (5th Edition). Needham Heights, MA: Allyn & Bacon.

XLIII.Tran, D. C. (2014). Multiple Corporate Governance Attributes and the Cost of Capital-Evidence from Germany. The British Accounting Review,46:179-197.

XLIV.Williams, R. (2015). Multicollinearity, University of Notre Dame, See also URL: http://www3.nd.edu/~rwilliam/. Last revised January 13, 2015.

XLV.Wooldridge, J.M. (2000). Introductory Econometrics: A Modern Approach, South Western.

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Effect of Fibers and Matrix Related Parameters on Workability and Compressive Strength


Muhammad Zahid,Nasir Shafiq,Muhammad Ali,Mohd Fadhil Nuruddin,Asif Jalal,




Geopolymer (GP) is a new generation of binder material in construction industry. Production of ordinary Portland cement (OPC) utilizes extensive energy as well as it emits large amount of CO2 into the atmosphere when compared to GP production. This paper focuses on the effect of polyvinyl alcohol (PVA) fibers, sand/fly ash and water/ geopolymer solids ratios on the workability and compressive strength of fly ash based geopolymer composite. Curing temperature, NaOH molarity and Na2Sio3/NaOH were kept as 60ᵒC, 8M and 2.5 respectively. Total of 2% (v/v) PVA fibers with cut length of 8mm and diameter of 0.04mm were utilized. Furthermore, sand/fly ash and water/ geopolymer solids (W/GP) ratios were varied in a range of 0-0.8 and 0.22-0.26 respectively. Results were evaluated with the help of response surface methodology. Reduction in workability was observed with the addition of fibers in matrix. Moreover, increase in sand/fly ash ratio caused decrease in workability and vice versa for the increase in water/ geopolymer solids ratio. Furthermore, Inclusion of fibers did not show considerable change in the compressive strength of geopolymer, however, when the workability of the matrix mixture kept relatively low, abrupt decrease in the compressive strength was observed with the addition of fibers. Increase in the sand/fly ash ratio contributes in the compressive strength up-to a certain limit. Additionally, increase in the W/GP solids ratio caused reduction in the compressive strength. Finally, multi-objective optimization technique revealed that the mix having W/GP solid =0.228848, and Sand/Fly ash =0.120947 would give optimized value.


Geopolymer, ,Fly Ash,Polyvinyl Alcohol (PVA) Fibers,Compressive Strength,Workability,


I.Ali, M. B., Saidur, R., & Hossain, M. S. (2011). A review on emission analysis in cement industries. Renewable and Sustainable Energy Reviews, 15(5), 2252–2261.

II.ASTM C109/C109M-16a. (2010). Standard Test Method for Compressive Strength ofHydraulic Cement Mortars ( Using 2-in . or [ 50-mm ] Cube Specimens ). ASTM International.

III.ASTM C1437. (2016). Standard Test Method for Flow of Hydraulic Cement Mortar. ASTM International.

IV.Christopher, F., Bolatito, A., & Ahmed, S. (2017). Gulf Organisation for Research and Development Structure and properties of mortar and concrete with rice husk ash as partial replacement of ordinary Portland cement –A review. International Journal of Sustainable Built Environment.

V.Chung, K. L., Ghannam, M., & Zhang, C.(2017). Effect of Specimen Shapes on Compressive Strength of Engineered Cementitious Composites (ECCs) with Different Values of Water-to-Binder Ratio and PVA Fiber. Arabian Journal for Science and Engineering.

VI.Davidovits, J. (1994). PROPERTIES OF GEOPOLYMER CEMENTS Joseph Davidovits Geopolymer Institute, 02100 Saint-Quentin, France. Alkaline Cements and Concretes, KIEV Ukraine, 1–19.

VII.Karim, M. R., Zain, M. F. M., Jamil, M., & Lai, F. C. (2013). Fabrication of a non-cement binder using slag, palm oil fuel ash and rice husk ash with sodium hydroxide. Construction and Building Materials, 49, 894–902.

VIII.Khotbehsara, M.M., Mohseni, E., Yazdi, M.A., Sarker, P., Ranjbar, M.M., 2015. Effect of nano-CuO and fly ash on the properties of self-compacting mortar. Constr. Build. Mater. 94, 758–766.

IX.Kim, Y., Hanif, A., Usman, M., Junaid, M., Minhaj, S., Kazmi, S., & Kim, S. (2018). Slag waste incorporation in high early strength concrete as cement replacement : Environmental impact and in fl uence on hydration & durability attributes. Journal of Cleaner Production, (2017).

X.Li, V. C., Mishra, D. K., & Wu, H. (1995). Matrix Design for Pseudo Strain-Hardening Fiber Reinforced Cementitious Composites. Materials and Structures, 28, 586–595.

XI.Liu, Z. (2015). China’s Carbon EmissionsReport 2015. Belfer Center for Science and International Affair.

XII.Makul, N., Rattanadecho, P., & Agrawal, D. K. (2014). Applications of microwave energy in cement and concrete -A review. Renewable and Sustainable Energy Reviews, 37, 715–733.

XIII.Manz, O. E. (1997). Worldwide production of coal ash and utilization in concrete and other products. Fuel, 76(8), 691–696.

XIV.Mukherjee, A. B., Zevenhoven, R., Bhattacharya, P., Sajwan, K. S., & Kikuchi, R. (2008). Mercury flow via coal and coal utilization by-products: Aglobal perspective. Resources, Conservation and Recycling, 52(4), 571–591.

XV.Nematollahi, B. design of strain hardening fiber reinforced engineered geopolymer composite, Sanjayan, J., & Shaikh, F. U. A. (2015). Matrix design of strain hardening fiber reinforced engineered geopolymer composite. Composites Part B: Engineering, 27(10), 253–265.

XVI.Wang, J., Wang, Y., Sun, Y., Tingley, D. D., & Zhang, Y. (2017). Life cycle sustainability assessment of fly ash concrete structures. Renewable and Sustainable Energy Reviews, 80(August), 1162–1174.

XVII.WBCSD, & IEA. (2009). Cement Technology Roadmap 2009: Carbon emissions reductions up to 2050.

XVIII.Zahid, M., Shafiq, N., Nuruddin, M. F., Nikbakht, E., & Jalal, A. (2017). Effect of Partial Replacement of Fly Ash by Metakaolin on Strength Development of Fly Ash Based Geopolymer Mortar. In Key Engineering Materials (Vol. 744, pp. 131–135). Switzerland: Trans Tech Publications.

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Application of Combined Mixture Process Design for Enhancement of Methane Production Using Co-digestion of Chicken Manure and Napier Grass


Supawadee Yodthongdee ,Panomchai Weerayutsil,Kulyakorn Khuanmar,




This research is aimed at application of Combined Mixture Process Design by Design Expert program in order to enhance the efficiency of methane production by co-digestion of chicken manure and Napier Pakchong 1 grass (Pennisetum purpureum. Schum), which enables deduction of operation time and cost for methane production. In addition, the impact of co-digestion in terms of C/N ratio was studied. The experimental result indicated that the Combined Mixture Process Design by biogas and methane yield as response variables were significantly appropriate based on the R2 at 93.99% and 93.67%, respectively. It also indicated the factors that enhance the maximum production of methane, i.e., the ratio of inoculum: chicken manure: Napier grass of 59.70: 6.02: 34.28%TS at the total solids of 2.5% of the working volume, pH 8, and 46°C. Such optimum conditions could yield accumulated biogas and accumulated methane of 920.88 ml/gVS and 492 mlCH4/gVS or 73.19%. Comparing to the individual digestion and the co-digestion, it was found that methane production presented the higher methane yield from the co-digestion of chicken manure and Napier grass.


Biogas,Methane Gas,Co-Digestion ,Chicken Manure,Napier Pakchong ,Combined Mixture Process Design,


I.Álvarez, J.A., Otero, L., Lema, J.M.(2010). A methodology for optimising feed composition for anaerobic co-digestion of agro-industrial wastes. Bioresour. Technol. 101(4): 1153-1158.

II.APHA and WEF. (2005). Standard methods for the examination of water and wastewater. 21: 258–259.

III.AOAC. Official Methods of Analysis. 12th ed.(1995)Association of Official Analytical Chemists, Washington, DC.

IV.Forster-Carneiro, T., Perez,M., Romero, L.I., (2007). Composting potential of different inoculum sources in the modified SEBAC system treatment of municipal solid wastes. Bioresour. Technol. 98: 3354–3366.

V.Hartman, H., Ahring, B.K. (2005). Anaerobic digestion of the organic fraction of municipal solid waste: Influence of co-digestion with manure. Water Research. 39(8):1543-1552.

VI.Habiba, L., Hassib, B., Moktar, H. (2009). Improvement of activated sludge stabilisation and filterability during anaerobic digestion by fruit and vegetable waste addition. Bioresour. Technol. 100, 1555–1560.

VII.Kaparaju, P., Rintala, J. (2011). Mitigation of greenhouse gas emissions by adopting anaerobic digestion technology on dairy, sow and pig farms in Finland. Renewable Energy 36(1):31–41.

VIII.Li, C., Stromberg, S., Liu, G., Nges, L.A, Liu, N. (2017). Assessment of regional biomass as co-substrate in the anaerobic digestion of chicken manure: Impact of co-digestion with chicken processing waste, seagrass and Miscanthus, Bioresour. Technol. 118:1-10.

IX.N. Subramonia Pillai, P. Seeni Kannan, S.C. Vettivel, S. Suresh. (2017). Optimization of transesterification of biodiesel using green catalyst derived from Albizia Lebbeck Pods by mixture design. Renewable Energy. 104:185-196.

X.Wang, X., Yang, G., Feng, Y.,Ren, G., Han, X. (2012). Optimizing feeding composition and carbon-nitrogen ratios for improved methane yield during anaerobic codigestion of dairy, chicken manure and wheat straw. Bioresour. Technol. 120:78–83.

XI.Wang, X., Yang, G., Li, F., Feng, Y., Ren,G., Han, X. (2013). Evaluation of two statistical methods for optimizing the feeding composition in anaerobic co-digestion: Mixture design and central composite design. Bioresour. Technol. 131:172-178.

XII.Wilawan, W., Pholchan, P. and Aggarangsi, P.(2014). Biogas production from co-digestion of Pennisetum purureum cv. Pakchong 1 Grass and layer chicken manure using completely stirred tank. Energy Procedia, 52:216-222.

XIII.Sosnowski, P.,Wieczorek, A., Ledakowicz, S. (2013). Anaerobic co-digestion of sewage sludge and organic fraction of municipal solid wastes. Advances in Environmental Research. 7(3): 609-616.

XIV.Mshandete, A., Kivaisi, A., Rubindamayugi, M., Mattiasson, B. (2004). Anaerobic batchco-digestion of sisal pulp and fish wastes. Bioresour. Technol.95(1):19–24.

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Treatment of Tilapia Wastewater by Using a Biofilter for Reuse in a Closed Recirculation Fish Culture System


Prapruet Thinpru,Panomchai Weerayutsil,Surapol Padungthon,Kulyakorn Khuanmar,




Ammonia treatment in a tilapia pond is considered of great significance, for cleaning and changing water in the pond can cost substantially while ammonia has a high toxicity to aquatic animals. In the experiment of the treatment of tilapia wastewater, a 10 L column reactor and a 10 L baffle reactor were employed. Two biofilter materials included bioball and fiberglass while two types of wastewater were synthetic wastewater and authentic wastewater. From experimenting on synthetic wastewater, it was found that on the same surface area of biofilter media, the baffle reactor could treat ammonia most effectively, yet the water was not reusable for tilapia culture. Therefore, the experiment was further conducted to enhance efficiency in the wastewater treatment for aquaculture. In the same-volume reactors, the surface area of fiberglass could be increased owing to fiberglass having higher void percentage. In contrast, the surface area could not be increased in the case of bioball because of their rigid shape and lower void percentage. Thus fiberglass was used instead in the experiment to enhance the efficiency in wastewater treatment. It was discovered that the biofilter system with the fiberglass used as the biofilter media on the 2.4 m2 could remove the ammonia in the wastewater, specifically decreasing it to 0.2 mg/L, which contributed to the reuse of water for a closed recirculation tilapia culture system.


Biofilter ,Ammonia removal,Column reactor ,affle reactor,


I.Barber, W. P., & Stuckey, D. C. (1999). The use of the anaerobic baffled reactor (ABR) for wastewater treatment: a review. Water Research, 33(7), 1559–1578.

II.Boongorsrang, A., SUGA, K., & MAEDA, Y. (1982). Nitrification of wastewaters containing organic carbon and inorganic nitrogen by rotating disc contactor. Journal of Fermentation Technology, 60(4), 357–362.

III.Cassidy, M., Lee, H., & Trevors, J. (1996). Environmental applications of immobilized microbial cells: a review. Journal of Industrial Microbiology, 16(2), 79–101.

IV.Rogers, G. L., & Klemetson, S. L. (1985). Ammonia removal in selected aquaculture water reuse biofilters. Aquacultural Engineering, 4(2), 135–154.

V.Rosa, M. F., Furtado, A. A., Albuquerque, R. T., Leite, S. G., & Medronho, R. A. (1998). Biofilm development and ammonia removal in the nitrification of a saline wastewater. BioresourceTechnology, 65z(1–2), 135–138.

VI.Wungkobkiat, A., Kucharoenphaibul, S., Sripunya, K., & Lekcholaryut, T. (2008). Intensive nitrification process employing immobilized nitrifiers on polyester carriers in closed-system aquaria. Kasetsart Journal-Natural Science, 42, 289–298.

VII.Yang, L., Chou, L.-S., & Shieh, W. K. (2001). Biofilter treatment of aquaculture water for reuse applications. Water Research, 35(13), 3097–3108.

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Wastewater Treatment from Textile Softening in Finishing Process by Aluminum Electrocoagulation


Jaturun Anukulprasert,Kulyakorn Khuanmar,Panomchai Weerayutsil,




In textile industry, there is always wastewater which is hard to treat. It is usually caused from fiber softening in finishing process. In this experimental study, electrocoagulation technique was employed with 6 types of softeners with different features and functions. The wastewater was synthesized by dissolving softeners in the treated wastewater from textile factory to manipulate the characteristic of synthesized wastewater so that its matrix became close to real wastewater. In examination of the removal efficiency, COD and TOC were water quality indicators. The experiments revealed that COD and TOC treatment efficiency was not dependent on the softeners’ features and functions, but the efficiency could be indicated by testing the sludge based on SEM and EDX techniques. According to the analysis of the elements in the flocs from electrocoagulation process by EDX, the amount of Al in the flocs was high, which means the synthetic wastewater could be effectively treated. In addition, the analysis from SEM showed morphology of sludge, which could be classified into 3 groups: powder, chunk, and flat sheet. Note that the flat-sheet flocs were well precipitated.


Softening in finishing process,Aluminum electrode ,Electrocoagulation,COD removal,


I.APHA, AWA, WPCF, 1992. Standard Methods for the Examination of Water and Wastewater, 18th ed. American Public Health Association, Washington, DC.

II.Aoudj, S., Khelifa, A., Drouiche, N., Hecini, M., & Hamitouche, H. (2010). Electrocoagulation process appliedto wastewater containing dyes from textile industry.Chemical Engineering and Processing: Process Intensification,49(11), 1176-1182.

III.Bensadok, K. S., Benammar, S., Lapicque, F., & Nezzal, G. (2008). Electrocoagulation of cutting oil emulsions using aluminium plate electrodes.Journal of hazardous materials,152(1), 423-430.

IV.Can, O. T., Bayramoglu, M., & Kobya, M. (2003). Decolorization of reactive dye solutions by electrocoagulation using aluminum electrodes.Industrial & engineering chemistry research,42(14), 3391-3396.

V.Can, O. T., Kobya, M., Demirbas, E., & Bayramoglu, M. (2006). Treatment of the textile wastewater by combined electrocoagulation. Chemosphere, 62(2), 181–187.

VI.Gürses, A., Yalçin, M., & Doar, C. (2002). Electrocoagulation of some reactive dyes: A statistical investigation of some electrochemical variables. Waste Management, 22(5), 491–499. https://doi.org/10.1016/S0956-053X(02)00015-6

VII.İrdemez, Ş., Demircioğlu, N., Yıldız, Y. Ş., & Bingül, Z. (2006). The effects of current density and phosphate concentration on phosphate removal from wastewater by electrocoagulation using aluminum and iron plate electrodes.Separation and Purification Technology,52(2), 218-223.

VIII.Kumar, P. R., Chaudhari, S., Khilar, K. C., & Mahajan, S. P. (2004). Removal of arsenic from water by electrocoagulation. Chemosphere, 55(9), 1245–1252.

IX.Kurt, U., Gonullu, M. T., Ilhan, F., & Varinca, K. (2008). Treatment of domestic wastewater by electrocoagulation in a cell with Fe–Fe electrodes. Environmental Engineering Science, 25(2), 153–162.

X.Manu, B., & Chaudhari, S. (2002). Anaerobic decolorisation of simulated textile wastewater containing azo dyes. Bioresource Technology, 82(3), 225–231.

XI.Pettit, F. S. (1994). Surface engineering of aluminum and aluminum alloys, 5, 2076–2079.

XII.Picard, T., Cathalifaud-Feuillade, G., Mazet, M., & Vandensteendam, C. (2000). Cathodic dissolution in the electrocoagulation process using aluminium electrodes. Journal of Environmental Monitoring, 2(1), 77–80.

XIII.Sardari, K., Fyfe, P., Lincicome, D., & Wickramasinghe, S. R. (2018). Aluminum electrocoagulation followed by forward osmosis for treating hydraulic fracturing produced waters.Desalination,428, 172-181..

XIV.Türgay, O., Ersöz, G., Atalay, S., Forss, J., & Welander, U. (2011). The treatment of azo dyes found in textile industry wastewater by anaerobic biological method and chemical oxidation. Separation and Purification Technology, 79(1), 26–33.

XV.Wahle, B., & Falkowski, J. (2002). Softeners in textile processing. Part 1: An overview.Coloration Technology,32(1), 118-124.

XVI.Wang, C.-T., Chou, W.-L., & Kuo, Y.-M. (2009). Removal of COD from laundry wastewater by electrocoagulation/electroflotation. Journal of Hazardous Materials, 164(1), 81–86.

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