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The palm and date sector is one of the most important sectors in Saudi Arabia. The total number of fertile palm trees in Saudi Arabia is about 31 million. In the production of pitted dates, date molasses, date paste, and date confectionery, a considerable number of date kernels are usually discarded as waste. This study reports experimental investigations conducted to evaluate the potential of waste date kernel ash (DKA), obtained by the calcination of date pits at 800 °C, as a partial cement replacement in concrete. DKA has low silica oxide and does not qualify as a pozzolanic material. The effect of DKA partially replacing the cement and acting as a filler material in concrete was investigated, and its properties were compared with two pozzolanic materials, fly ash (FA) and natural pozzolan (NP). Twelve concrete mixes in which cement was replaced with different proportions of calcined DKA (5%, 10%, 15%, 20%, and 30%), NP (10%, 20%, and 30%), and FA (10%, 20%, and 30%) were investigated in the experimental program. The properties of DKA, FA, and NP concrete mixes were evaluated in fresh and hardened states, including the heat of hydration, mechanical characteristics, and thermal properties. The results show that replacing cement with 5% date kernel ash increases the compressive strength by 0.42%, 3.2%, and 2.5% at 3, 7, and 28 days, respectively, while the 28-day compressive strength decreases by 2.4%, 5.4%, 16.3%, and 26.69% when the cement is replaced with 10%, 15%, 20%, and 30% DKA, respectively. Date kernel ash concrete mixes with 10%, 20%, and 30% replacement levels demonstrated higher compressive and tensile strengths and lower thermal conductivity, density, and workability when compared to natural pozzolan and fly ash. DKA is a promising partial cement replacement material; nevertheless, additional research is required to assess the durability of DKA in concrete.

Concrete water tanks have a stringent serviceability requirement in terms of limiting crack widths. Excessive cracks or cracks running across the full depth of these tanks could result in l...

Evolution of heat due to an exothermic reaction between cementitious materials and water plays a significant role in the temperature rise in mass concrete at an early age. The temperature gradient between the core of mass concrete and its surfaces leads to the development of thermal stresses and may cause cracking if these stresses exceed the evolving tensile strength of concrete. This paper presents the results of an experimental and finite-element investigation of heat generation and dissipation in full-scale mass concrete blocks 2 m × 2 m × 2 m in size. A concrete mix with 100% OPC and 70% cement replaced by GGBFS was used in these blocks. The temperature profile across the depth of the block was measured at the centre, side and corner of the block. A semi-adiabatic calorimeter was used to measure the heat of hydration of the two concrete mixes. Finite-element simulation of these blocks captured with good accuracy the measured evolution of temperature in the blocks. Numerical simulation was subsequently used to investigate the influence of the size of the blocks, placement temperature of concrete, ambient temperature, solar radiation and type of formwork on the temperature rise and the associated potential of cracking in the mass concrete blocks.

As we can cure the conductive deafness by surgery, the sensori neural deafness is still a challenge to us. Children having mixed loss of hearing invariably suffer from the point of view of education and development of language and therefore it becomes essential to study such cases so that we can prevent the sensori neural deafness in chronic suppurative otitis media. One hundred patients of chronic suppurative otitis media with sensori neural hearing loss, either alone or more commonly, with mixed loss were studied in this series. The patients were carefully selected after proper history and careful examination to exclude the above mentioned criteria to rule out the other possible causes of sensori neural loss. Though cases with use of ototoxic systemic drugs were rejected, cases with use of topical ear drops were included as their use was found to be common in chronic otitis media. The different ear drops used by patients showed large variety of nature of contents and varying period of use. Many patients could not inform the name of the drops they had used in past. In our study, use of topical antibiotic ear drops for long duration as a cause of sensori neural hearing loss was not statistically significant.

Purpose: We reviewed our experience with mullerian duct remnants, also known as prostatic utricular and mullerian duct cysts, to advance further the understanding of the surgical management of these challenging congenital anomalies. The indications, merits and disadvantages of each surgical approach are presented, and the effects of mullerian duct remnants and their treatment on future fertility are discussed.Materials and Methods: We reviewed the records of 26 patients 1 month to 19 years old with mullerian duct remnants who were seen between January 1984 and October 1998. Clinical presentation included perineoscrotal hypospadias in 10 cases, urinary retention and/or difficult voiding in 7, urinary tract infection in 6, acute scrotum in 2, and recurrent hemospermia and dysuria in 1.Results: Of the 26 patients 13 required surgical intervention for various symptoms and to correct large diverticula. The surgical approach was transvesical transtrigonal in 8 cases, extravesical in 2, perineal in 2 and...

This paper presents the results of thermo-mechanical characterization of Glass/Epoxy composite specimens using Infrared Thermography technique. The specimens used for the study were fabricated in-house with three different lay-up sequences and tested on a servo hydraulic machine under uni-axial loading. Infrared Camera was used for on-line monitoring surface temperature changes of composite specimens during tensile deformation. Experimental results showed that thermomechanical characteristics of each type of specimens were distinct. Temperature was found to be decreasing linearly with increasing tensile stress in the elastic region due to thermo-elastic effect. Yield point could be observed by monitoring the change in temperature profile during tensile testing and this value could be correlated with the results obtained from stress-strain response. The extent of prior plastic deformation in the post-yield region influenced the slopes of temperature response during tensile loading. Partial unloading and reloading of specimens post-yield results in change in slope in elastic and plastic regions of composite specimens., {"references":["Dunn SA, \"Separation of strain components in composite materials from\nthermoelastic temperature measurements\", J. Appl. Mech. 60, 443-448,\n1991.","EI-Hajjar RF and Haj-Ali RM, \"Aquantitative thermoelastic stress\nanalysis method for pultruded composites\", Comp. Sci. and\nTech.63.967-978, 2003.","Lee HT and Chen JC, \"Temperature effect induced by uniaxial tensile\nloading\", J.Mater.Science, 26, 5685-5692, 1991.","Lindhagen JE and Berglund L A, \"Temperature changes in polymer\ncomposites during tensile loading\"J.Mater.Science.32, 4071-4076, 1997.","Zhang D, Enke NF and Sandor BI, \"Thermographic stress analysis of\ncomposite materials\", Exp.Mech.68-73, 1990.","Dunn SA, \"Analysis of thermal conduction effects on thermoelastic\ntemperature measurements for composite materials\", J.Appl.Mech.60,\n443-448,1991","Patil.P. Thiyagarajan K, Prakash VP and Balasubramaniam K, \"Damage\ncharacterization in SS 304 due to monotonic loading using infrared\nthermography\", Int.J Adv.Manuf.Technol.special issue,2008.","Bakis CE and Reifsnider KL, \"The adiabatic thermoelastic effect in\nlaminated fiber composites\", J.Compos.Mater.25, 809-30, 1991.","Wong AK, \"A non-adiabatic thermoelastic theory for composite\nlaminates\", J Phys Chem Solid, 52,483-94, 1991.\n[10] Cunningham PR, Dalieu-Barton JM, Dutton AG and Shenoi RA, \"The\neffect of ply lay-up on the thermoelastic response of laminated\ncomposites\", Key Eng Mater, 221-222,325-36, 2002.\n[11] Emery TR, Dalieu-Barton JM, Earl JS and Cunningham PR,\"A\ngeneralised approach to the calibration of orthotropic materials for\nthermoelastic stress analysis \", Comp Sci Technol, 63(7),967-78,2003.\n[12] Tsai SW, \"Strength characteristics of composite materials\", NASA CR-\n224, April 1965.\n[13] Chung K and Ryou H, \"Development of viscoelastic/rate-sensitiveplastic\nconstitutive law for fiber-reinforced composites and its\napplications. Part 1: Theory and material characterization\", Comp. Sci.\ntech.69, 284-291, 2009.\n[14] Heubert H, Schulte K and Harig, \"Composite materials: Testing and\ndesign\",Vol.9,edited by S.P.Garbo (ASTM-STP 0066-1058;1059) p.435\n[15] Toubal L, Karama M and Lorrain B, \"Damage Evolution and Infrared\nThermography in Woven Composite Laminates Under Fatigue Loading\",\nInt. J. of Fatigue, Vol. 28, 2006 p. 1867 - 1872"]}