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Breastfeeding has been receiving much attention of late. Prolonged sitting for breastfeeding often results in back pain of the mothers. This paper reports the findings of a study on the effect of some factors, especially lumbar support, on back pain of breastfeeding mothers. The results showed that the use of lumbar support can reduce back pain of breastfeeding mothers significantly. Back pain was found to increase with breastfeeding time and the rate of increase was lower when lumbar supports were used. When lumbar support thickness was increased gradually from zero (no support) to 11 cm., the degree of low back pain decreased; rapidly at first, then slowly, and leveled off when the thickness reached 9 cm. Younger mothers were less prone to back pain than older mothers. The implications of the findings are discussed., {"references":["Continuing Education Unit, Breastfeeding/ Data and Statistics/ U.S.\nNational Immunization Survey, (2010, 07, 17). Breastfeeding Among\nU.S. Children Born 1999ÔÇö2006. Available: http://www.cdc.gov.","UNICEF Thailand, Real lives/ Health, (2010, 08, 26).When breast is\nbest. Available: http://www.unicef.org/thailand/","K. Grimmer and M. Williams,\" Gender-age environmental associates of\nadolescent low back pain,\" Applied Ergonomics, vol. 31, pp. 343-360,\n2000.","Tyson A.C. Beach, Robert J. Parkinson, J. Peter Stothart,Jack P.\nCallaghan, \" Effects of prolonged sitting on the passive flexion stiffness\nof the in vivo lumbar spine,\" Spine, vol. 5, pp. 145-154, 2005.","C. Campbell, S.J. Muncer, \" The causes of low back pain: a network\nanalysis,\" Social Science & Medicine, vol. 60, pp. 409-419, 2005.","Andersson GBJ, \" Epidemiologic aspects on low back pain in industry,\"\nSpine , vol. 6, pp. 53-60, 1981.","Bendix, T., Poulsen, V., Klausen, K., Jensen, C. v., \" What does a\nbackrest actually do to the lumbar spin?, \" Ergonomic , vol.39,\n[Online],Available : www.sciencedirect.com, [(1996) pp.533-542].","Steven M. Carcone and P. J. Keir,\" Effects of backrest design on\nbiomechanics and comfort during seated work,\" Applied Ergonomics,\nvol. 38, pp. 755-764, 2007.","M. Lengsfeld, A. Frank, D. L. van Deursen and P. Griss,\" Lumbar spine\ncurvature during office chair sitting,\" Medical Engineering & Physics,\nvol. 22, pp. 7665-669, 2000.\n[10] Andersson GB, Murphy RW, Ortengren R, Nachemson AL, \"The\ninfluence of backrest inclination and lumbar support on lumbar\nlordosis,\" Spine , vol. 4, pp. 52-58, 1979.\n[11] Williams, M., Hawley, J., Mckenzie, R., van Williams, P., \" A\ncomparison of the effects of two sitting postures on back and referred\npain.\", Spine, vol.16, (Online),Available : www.sciencedirect.com,\n[(1991) pp.1185-91]."]}

This research aimed to modify pineapple leaf paper (PALP) for using as wet media in the evaporation cooling system by improving wet mechanical property (tensile strength) without compromising water absorption property. Polyamideamineepichorohydrin resin (PAE) and carboxymethylcellulose (CMC) were used to strengthen the paper, and the PAE and CMC ratio of 80:20 showed the optimum wet and dry tensile index values, which were higher than those of the commercial cooling pad (CCP). Compared with CCP, PALP itself and all the PAE/CMC modified PALP possessed better water absorption. The PAE/CMC modified PALP had potential to become a new type of wet media., {"references":["T. Gunhan, V. Demir and A.K. Yagcioglu, \"Evaluation of the Suitability\nof Some Local Materials as Cooling Pads,\" Biosystems Engineering,\nvol.96, no.3, pp.369-377, January 2007.","J. Prasomsub, \"Feasibility of Evaporative Cooling Application in\nFlower's Greenhouse,\" Master of Science Program in Energy\nTechnology, School of Energy, Environment and Materials, King\nMongkut's University of Technology Thonburi. 1998.","S. Mongkon, \"Feasibility of Evaporative Cooling System Together with\nNatural Ventilation in Flower Growing Greenhouse,\" Master of\nEngineering Program in Energy Technology, School of Energy,\nEnvironment and Materials, King Mongkut's University of Technology\nThonburi. 2004.","A. Rattanathanaopat, \"Improving in Efficiency of Evaporative Cooling\nin Poultry,\" Master of Engineering Program in Thermal Technology,\nSchool of Energy, Environment and Materials, King Mongkut's\nUniversity of Technology Thonburi. 2003.","N. Sangkhapitak, \"Study in evaporative cooling media for agricultural\napplication,\" Master of Engineering Program in Thermal Technology,\nSchool of Energy, Environment and Materials, King Mongkut's\nUniversity of Technology Thonburi. 2001.","\"Pineapple production\" [Online] Available from http://fao.org\n[Accessed from 20/4/2009]","H. H. Espy, \"The mechanism of wet-strength development in paper: a\nreview,\" Tappi Journal, vol.78, No.4, pp.90-99, April 1995.","C.O. Au and I. Thorn, Applications of Wet-End Paper Chemistry,\nGlasgow : Chapman & Hall, 1995, pp.2-3.","J.C. Roberts, Paper Chemistry, 2nd ed., London : Chapman & Hall,\n1996, pp.98-119.\n[10] R. Gernandt, L. Wagberg, L. Gardlund and H. Dautzenberg,\n\"Polyelectrolyte complexes for surface modification of wood fibres I.\nPreparation and characterization of complexes for dry and wet strength\nimprovement of paper,\" Colloids and Surfaces A: Physicochem. Eng.\nAspects, vol.213, pp.15-25, June 2002.\n[11] L. Gardlund, L. Wagberg, and R. Gernandt, \"Polyelectrolyte complexes\nfor surface modification of wood fibres II. Influence of complexes on\nwet and dry strength of paper,\" Colloids and Surfaces A: Physicochem.\nEng. Aspects , vol.218, pp.137-149, December 2002.\n[12] T. Obokata and A. Isogai, \"The mechanism of wet-strength\ndevelopment of cellulose sheets prepared with polyamideamineepichlorohydrin\n(PAE) resin,\" Colloids and Surfaces A: Physicochem.\nEng. Aspects, vol.302, pp.525-531, March 2007\n[13] D. Braga, G. Kramer, R. Pelzer and M. Halko, \"Recent Development in\nWet Strength Chemistry Targeting High Performance and Ambitious\nEnvironment Goals,\" Chemical Technology, pp.30-34, September 2009.\n[14] E. Kontturi, M. Mitikka-Eklund and T. Vuorinen, \"Strength\nenhancement of a fiber network by carboxymethyl cellulose during\noxygen delignification of kraft pulp,\" BioResources, vol.3, No.1,\npp.34-45, January 2008.\n[15] J. P. Casey, Pulp and Paper: Chemistry and Chemical Technology\nVolume I, 3rd ed., New York: John wiley & sons, 1980, pp.18-23."]}

In this research sodium bicarbonate (NaHCO3) was introduced to generate carbon dioxide gas (CO2) to the existing nitrogen gas (N2) of elastomeric foam, to lower thermal conductivity (K). Various loadings of NaHCO3 (0 to 60 phr) were added into the azodicarbonamide (AZC)-containing compound and its properties were then determined. Two vulcanization methods, i.e., hot air and infrared (IR), were employed and compared in this study. Results revealed that compound viscosity tended to increase slightly with increasing NaHCO3 content but cure time was delayed. The effect of NaHCO3 content on thermal conductivity depended on the vulcanization method. For hot air method, the thermal conductivity was insignificantly changed with increasing NaHCO3 up to 40 phr whereas it tended to decrease gradually for IR method. At higher NaHCO3 content (60 phr), unexpected increase of thermal conductivity was observed. The water absorption was also determined and foam structures were then used to explain the results., {"references":["\"Energy Crisis\" (online) Available from\nhttp://en.wikipedia.org/wiki/energy_crisis [Accessed from 12/4/2009].","A. Bahadori and H. B. Vuthaluru, \"A simple correlation for estimation\nof economic thickness of thermal insulation for process piping and\nequipment,\" Applied Thermal Engineering, vol. 30, pp. 254-259, August\n2009.","\"Thermal Conductivity of Material\" [online] Available from\nhttp://www.engineeringtoolbox.com/thermal-conductivity-d_429.html\n[Accessed from 8/4/2009].","J.C. Rubio-Avalos, A. Manzano-Ramirez, J.M. Yañez-Limón, M.E.\nContreras-Garcia, E.M. Alonso-Guzman and J. González-Hernández, \"\nDevelopment and characterization of an inorganic foam obtained by\nusing sodium bicarbonate as a gas generator\" Construction and Building\nMaterials, vol. 19, pp. 543-549, December 2004.","D. L. Tomasko, A. Burley, L. Feng, S. Yeh, K. Miyazono, S. Nirmal-\nKumar, I. Kusaka and K. Koelling, \" Development of CO2 for polymer\nfoam applications\" The Journal of Supercritical Fluids, vol. 47, pp. 493-\n499, October 2008.","G. G. Gusavage, H. G. Schirmer and T. A. Hessen, \"Foam and process\nfor producing foam using a carbon dioxide blowing agent\" US Patent\nNumber 5670552, September 1997.","R. M. Lapierre and N. J. Leonardi, \"Chemical blowing agent\ncompositions\" US Patent Number 4769397, September 1988.","V. Padareva, S. Djoumaliisky, N. Touleshkov and G. Kirov,\n\"Modification of blowing agent system based on sodium bicarbonate\nwith activated natural zeolite\" J. of Materials Science Letters, vol. 17,\npp. 107-109, September 1997.","J. R. Schauder and G. Stella, \"The unique design latitude of EPDM\"\nRubber World, pp. 23-27, March 1993.\n[10] \"Thermal Conductivity of Sodium Chloride\" (online)\nhttp://www.almazoptics.com/NaCl.htm (Accessed from 22/6/2010).\n[11] J. H. Lienhard, \"A heat transfer text book\", Prentice-Hall, Inc, 1987, pp.\n4-28."]}