Culture in rural water and sanitation projects: a case study

A case study of a water and sanitation project under construction in Emem, Ghana is used as a basis for consideration of how culture impacts on the engineering design and implementation of projects in rural communities in less developed countries. The hypothesis is that local culture is an important consideration if long term sustainability is to be achieved. It was found that, contrary to expectations, cultural issues such as religious belief had no direct bearing on the design parameters of the project. However, an understanding of local culture was vital in establishing lines of communication during the construction phase. Different attitudes to problem solving between foreign engineers and local people created some problems, but in other cases were complementary. It is concluded that engineers working on such projects need a clear understanding of their own world view in order to relate properly to their clients

H‐adaptive finite element solution of unsteady thermally driven cavity problem

An h‐adaptive finite element code for solving coupled Navier‐Stokes and energy equations is used to solve the thermally driven cavity problem for Rayleigh numbers at which no steady state exists (greater than 1.9 × 108). This problem is characterised by sharp thermal and flow boundary layers and highly advection dominated transport, which normally requires special algorithms, such as streamline upwinding, to achieve stable and smooth solutions. It will be shown that h‐adaptivity provides a suitable solution to both of these problems (sharp gradients and advection dominated transport). Adaptivity is also very effective in resolving the flow physics, characterised by unsteady internal waves, are calculated for three Rayleigh numbers; 2 × 108, 3 × 108 and 4 × 108 using a Prandtl number of 0.71 and results are compared with other published results.EPSRC research studentshi

H‐adaptive finite element solution of high Rayleigh number thermally driven cavity problem

An h‐adaptive finite element code for solving coupled Navier‐Stokes and energy equations is used to solve the thermally driven cavity problem. The buoyancy forces are represented using the Boussinesq approximation. The problem is characterised by very thin boundary layers at high values of Rayleigh number (>106). However, steady state solutions are achievable with adequate discretisation. This is where the auto‐adaptive finite element method provides a powerful means of achieving optimal solutions without having to pre‐define a mesh, which may be either inadequate or too expensive. Steady state and transient results are given for six different Rayleigh numbers in the range 103 to 108 for a Prandtl number of 0.71. The use of h‐adaptivity, based on a posteriori error estimation, is found to ensure a very accurate problem solution at a reasonable computational cost

Innovative learning at The University of Edinburgh

The activities available to civil engineering students during the University of Edinburgh's innovative learning week in 2012 were examined. The academic staff proposed a wide range of possible activities and student participation was optional. Popular activities were those with a ‘hands-on’ element: making or doing something. The practical activities offered included designing and building trebuchets, relaying railway permanent way on a heritage railway, practical workshops on engineering in international development and learning to juggle. These activities suggested that heuristic learning by trial and error was likely to enhance the visualisation skills that contribute to good engineering design. Further, the linking of achievement to purposeful practice rather than innate talent could inform teaching methods in the future. They also showed that in some cases safety culture messages were still not fully assimilated by students

Alternatives to the use of synthetic organic coagulant aids in drinking water treatment: improvements in the application of the crude extract of Moringa oleifera seed

[EN] Drinking water treatment is a process based on multiple stages that has a main objective to provide water safe enough to be consumed by humans. Coagulation–flocculation is used to remove colloidal and suspended solids. This process improves the performance of subsequent stages (as sedimentation or filtration) as well as the water quality with a desired end-use. For many years, inorganic and organic synthetic polyelectrolytes have been used in coagulation–flocculation processes. However, its use has been deeply studied recently to determine the potential impact of residual concentration of these substances on human health and the environment. Strict regulations limit the concentration of free residual monomer after the addition of polyacrylamide (PAM) in drinking water treatment and study the effect of interaction of the residues with disinfection products. Therefore, in the last years there has been a resurgence of interest to use natural materials with the same performance that synthetic, but with lower hazard for the environment and humans. This work studies the use of the flocculant extracted from Moringa oleifera seed, in combination with polyaluminum chloride (PAC). The performance is compared with the combination PAC–PAM in terms of coagulant activity and physical–chemical quality of the water treated. Jar test was carried out using two types of natural water (with presence of bentonites) and different combinations of coagulant and flocculants. Results show that coagulant activity of PAC–Moringa combination is comparable with the results obtained with PAC–PAM, reducing initial turbidity up to 90% in all the tests. With regard to physical–chemical quality of the treated water, PAC–Moringa produces values under the drinking water quality standards for all the parameters analyzed. It is remarkable that the decrease of 50% in the trihalomethanes formation potential rate shown for PAC–Moringa combination, observed when treating natural water with presence of bentonites. Therefore, the results obtain in this work encourage the use of Moringa oleifera extract as a natural, low cost, effective, and low-toxicity alternative to the use of synthetic organic polyelectrolytes as polyacrylamide for drinking water treatment.This research has been done in the framework of the project “Study of synthetic and natural coagulants susceptible of being used in the water treatment plant of “Ribarroja del Turia” (Valencia) as substitutes for polyacrylamide”. The authors wish to thank the staff of the laboratory of the Department of Water Quality of the company “Aguas de Valencia” located in La Presa (Manises) for its collaboration in the water tests of this work.García Fayos, B.; Arnal Arnal, JM.; Monforte Monleon, L.; Sancho Fernández, MP. (2015). Alternatives to the use of synthetic organic coagulant aids in drinking water treatment: improvements in the application of the crude extract of Moringa oleifera seed. Desalination and Water Treatment. 55(13):3635-3645. doi:10.1080/19443994.2014.939487S363536455513Van Benschoten, J. E., & Edzwald, J. K. (1990). Chemical aspects of coagulation using aluminum salts—I. Hydrolytic reactions of alum and polyaluminum chloride. Water Research, 24(12), 1519-1526. doi:10.1016/0043-1354(90)90086-lBOLTO, B. (1995). Soluble polymers in water purification. Progress in Polymer Science, 20(6), 987-1041. doi:10.1016/0079-6700(95)00010-dCrapper, D. R., Krishnan, S. S., & Dalton, A. J. (1973). Brain Aluminum Distribution in Alzheimer’s Disease and Experimental Neurofibrillary Degeneration. Science, 180(4085), 511-513. doi:10.1126/science.180.4085.511Davison, A. M., Oli, H., Walker, G. S., & Lewins, A. M. (1982). WATER SUPPLY ALUMINIUM CONCENTRATION, DIALYSIS DEMENTIA, AND EFFECT OF REVERSE-OSMOSIS WATER TREATMENT. The Lancet, 320(8302), 785-787. doi:10.1016/s0140-6736(82)92678-2Rondeau, V., Commenges, D., Jacqmin-Gadda, H., & Dartigues, J.-F. (2000). Relation between Aluminum Concentrations in Drinking Water and Alzheimer’s Disease: An 8-year Follow-up Study. American Journal of Epidemiology, 152(1), 59-66. doi:10.1093/aje/152.1.59Rondeau, V. (2001). RE: ALUMINUM IN DRINKING WATER AND COGNITIVE DECLINE IN ELDERLY SUBJECTS: THE PAQUID COHORT. American Journal of Epidemiology, 154(3), 288-a-290. doi:10.1093/aje/154.3.288-aGauthier, E., Fortier, I., Courchesne, F., Pepin, P., Mortimer, J., & Gauvreau, D. (2000). Aluminum Forms in Drinking Water and Risk of Alzheimer’s Disease. Environmental Research, 84(3), 234-246. doi:10.1006/enrs.2000.4101Kawamura, S. (1976). Considerations on Improving Flocculation. Journal - American Water Works Association, 68(6), 328-336. doi:10.1002/j.1551-8833.1976.tb02421.xA.D. Faust, O.M. Aly, Chemistry of Water Treatment, Butterworths, Boston, MA, 1983, pp. 326–328.Martenson, C. H., Sheetz, M. P., & Graham, D. G. (1995). In Vitro Acrylamide Exposure Alters Growth Cone Morphology. Toxicology and Applied Pharmacology, 131(1), 119-129. doi:10.1006/taap.1995.1053Kaggwa, R. C., Mulalelo, C. I., Denny, P., & Okurut, T. O. (2001). The impact of alum discharges on a natural tropical wetland in uganda. Water Research, 35(3), 795-807. doi:10.1016/s0043-1354(00)00301-8Dearfield, K. L., Abernathy, C. O., Ottley, M. S., Brantner, J. H., & Hayes, P. F. (1988). Acrylamide: its metabolism, developmental and reproductive effects, genotoxicity, and carcinogenicity. Mutation Research/Reviews in Genetic Toxicology, 195(1), 45-77. doi:10.1016/0165-1110(88)90015-2McCollister, D. D., Oyen, F., & Rowe, V. K. (1964). Toxicology of acrylamide. Toxicology and Applied Pharmacology, 6(2), 172-181. doi:10.1016/0041-008x(64)90103-6BOLTO, B., & GREGORY, J. (2007). Organic polyelectrolytes in water treatment. Water Research, 41(11), 2301-2324. doi:10.1016/j.watres.2007.03.012World Health Organization, Guidelines for drinking-water quality: Incorporating first and second addenda, in: World Health Organization (Ed.) Recommendations, third ed., vol. 1, World Health Organization, Geneva, 2008, pp. 188–194.Hamilton, M. A. (1994). A Statistician’s View of the U.S. Primary Drinking Water Regulation on Coliform Contamination. Environmental Science & Technology, 28(11), 1808-1811. doi:10.1021/es00060a009J. Criddle, A review of the mammalian and aquatic toxicity of polyelectrolites, NR 2545 Medmenhan, Foundation for Water Research 1990.Hebert, A., Forestier, D., Lenes, D., Benanou, D., Jacob, S., Arfi, C., … Levi, Y. (2010). Innovative method for prioritizing emerging disinfection by-products (DBPs) in drinking water on the basis of their potential impact on public health. Water Research, 44(10), 3147-3165. doi:10.1016/j.watres.2010.02.004Gerecke, A. C., & Sedlak, D. L. (2003). Precursors ofN-Nitrosodimethylamine in Natural Waters. Environmental Science & Technology, 37(7), 1331-1336. doi:10.1021/es026070iCharrois, J. W. A., Arend, M. W., Froese, K. L., & Hrudey, S. E. (2004). DetectingN-Nitrosamines in Drinking Water at Nanogram per Liter Levels Using Ammonia Positive Chemical Ionization. Environmental Science & Technology, 38(18), 4835-4841. doi:10.1021/es049846jS.A.A. Jahn, Proper use of African natural coagulants for rural water supplies- Research in the Sudan and a guide for new projects, Deutsche Gesellschaft für Technische Zusammenarheit (GTZ), Eschborn, 1986.Dorea, C. C. (2006). Use of Moringa spp. seeds for coagulation: a review of a sustainable option. Water Science and Technology: Water Supply, 6(1), 219-227. doi:10.2166/ws.2006.027Kawamura, S. (1991). Effectiveness of Natural Polyelectrolytes in Water Treatment. Journal - American Water Works Association, 83(10), 88-91. doi:10.1002/j.1551-8833.1991.tb07236.xLee, S. H., Lee, S. O., Jang, K. L., & Lee, T. H. (1995). Microbial flocculant from Arcuadendron sp. TS-49. Biotechnology Letters, 17(1), 95-100. doi:10.1007/bf00134203Effect of synthetic and natural coagulant on lignin removal from pulp and paper wastewater. (1997). Water Science and Technology, 35(2-3). doi:10.1016/s0273-1223(96)00943-2Broekaert, W. F., Cammue, B. P. A., De Bolle, M. F. C., Thevissen, K., De Samblanx, G. W., Osborn, R. W., & Nielson, K. (1997). Antimicrobial Peptides from Plants. Critical Reviews in Plant Sciences, 16(3), 297-323. doi:10.1080/07352689709701952Jahn, S. A. A. (1988). Using Moringa Seeds as Coagulants in Developing Countries. Journal - American Water Works Association, 80(6), 43-50. doi:10.1002/j.1551-8833.1988.tb03052.xMuyibi, S. A., & Okuofu, C. A. (1995). Coagulation of low turbidity surface waters withMoringa oleiferaseeds. International Journal of Environmental Studies, 48(3-4), 263-273. doi:10.1080/00207239508710996Ndabigengesere, A., Narasiah, K. S., & Talbot, B. G. (1995). Active agents and mechanism of coagulation of turbid waters using Moringa oleifera. Water Research, 29(2), 703-710. doi:10.1016/0043-1354(94)00161-yOkuda, T., Baes, A. U., Nishijima, W., & Okada, M. (2001). Isolation and characterization of coagulant extracted from moringa oleifera seed by salt solution. Water Research, 35(2), 405-410. doi:10.1016/s0043-1354(00)00290-6Ghebremichael, K. A., Gunaratna, K. R., Henriksson, H., Brumer, H., & Dalhammar, G. (2005). A simple purification and activity assay of the coagulant protein from Moringa oleifera seed. 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Progression of Wave Breaker Types on a Plane Impermeable Slope, Depending on Experimental Design

M. V. Moragues was supported by the research group TEP-209 (Junta de Andalucia) and by the following projects: "Protection of coastal urban fronts against global warming-PROTOCOL" (917PTE0538), "Integrated verification of the hydrodynamic and structural behavior of a breakwater and its implications on the investment project-VIVALDI" (BIA2015-65598-P). This work was funded by the projects PCI2019-103565-SUSME and PID2019-107509GB-I00-ROMPEOLAS (SRA (State Research Agency)/10.13039/501100011033). M. A. Losada was partially funded by the emeritus professorship mentoring program of the University of Granada. We would like to thank the three reviewers for providing helpful comments on earlier drafts of the manuscript.The objective of this research was to analyze the progression of breaker types on plane impermeable slopes. This study used dimensional analysis to demonstrate the relative water depth is a key explanatory quantity. The dominant breaker types depend on the incident wave characteristics at the foot of the slope. Accordingly, it is possible to combine values of H, T, and m. The physical experiments of Galvin, recent numerical results, and new experiments, performed on an impermeable 1:10 slope, were used to verify the result. It was thus possible to obtain the progression of breaker types in different sequences of pairs of combined wave H and T values. Once a sequence is defined, the expected progression of breaker types is predictable, and is well approximated by the log-transform of the alternate similarity parameter. Since the classification of breaker types is discontinuous, the data assigned to each type were placed in horizontal lines, based on the value of log(chi). Given that the breaking of a wave train on a slope should be considered a continuous process, the location of some data was corrected to satisfy this assumption. There is thus a functional relationship between the sets of the experimental space and of the breaker types. This research also derives the non-dimensional energy dissipation on the slope, considering the wave-reflected energy flux on the slope. It is proportional to a dimensionless bulk dissipation coefficient which depends on the breaker type and, therefore, on the value of chi at the toe of the slope.Junta de Andalucia 917PTE0538 BIA2015-65598-Pemeritus professorship mentoring program of the University of GranadaPCI2019-103565-SUSMEPID2019-107509GB-I00-ROMPEOLAS10.13039/50110001103

Stationary rotary force waves on the liquid–air core interface of a swirl atomizer

A one-dimensional wave equation, applicable to the waves on the surface of the air-core of a swirl atomizer is derived analytically, by analogy to the similar one-dimensional wave equation derivation for shallowwater gravity waves. In addition an analogy to the flow of water over a weir is used to produce an analytical derivation of the flow over the lip of the outlet of a swirl atomizer using the principle of maximum flow. The principle of maximum flow is substantiated by reference to continuity of the discharge in the direction of streaming. For shallowwater gravity waves, the phase velocity is the same expression as for the critical velocity over the weir. Similarly, in the present work, the wave phase velocity on the surface of the air-core is shown to be the same expression as for the critical velocity for the flow at the outlet. In addition, this wave phase velocity is shown to be the square root of the product of the radial acceleration and the liquid thickness, as analogous with the wave phase velocity for shallow water gravity waves, which is the square root of the product of the acceleration due to gravity and the water depth. The work revisits the weirs and flumes work of Binnie et al. but using a different methodology. The results corroborate with the work of Binnie. High speed video, Laser Doppler Anemometry and deflected laser beam experimental work has been carried out on an oversize Perspex (Plexiglas) swirl atomizer. Three distinctive types of waves were detected: helical striations, low amplitude random ripples and low frequency stationary waves. It is the latter wave type that is considered further in this article. The experimentally observed waves appear to be stationary upon the axially moving flow. The mathematical analysis allows for the possibility of a negative value for the phase velocity expression. Therefore the critical velocity and the wave phase velocity do indeed lead to stationary waves in the atomizer. A quantitative comparison between the analytically derived wave phase velocity and that measured experimentally, for this stationary pulsating wave, show very good agreement within a few percent

Experimental aluminum pathology in rabbits: effects of hydrophilic and lipophilic compounds.

Aluminum lactate [Al(lact)3] (hydrophilic, hydrolytically unstable) and aluminum acetylacetonate [Al(acae)3] (lipophilic, hydrolytically stable) were tested as potential toxicants to rabbits upon IV administration both as aqueous solutions and as liposome suspensions. Both chemicals behaved as cardiotoxic agents when administered as aqueous solutions, but Al(acae)3 was at least two orders of magnitude more active than Al(lact)3. Al(acae)3, but not Al(lact)3, caused myocardial infarcts resembling those in humans (with contraction bands) at doses as low as 0.24 mg/kg body weight, as well as a prominent acanthocytosis. Al(lact)3, when administered as a liposome suspension, was about 300 times more toxic than in aqueous solution, although cardiac damage was not infarctual in character. Both chemical and physical speciation of aluminum(III) thus play an essential role in determining the toxicity of the metal