Research collaboration

AbstractThe complexity and cost of cardiovascular medical care dictate research to deliver high quality and cost-conscious cardiovascular care. This goal is aided by modeling medical decision making. To be useful, the modeling must be based on real data so that the results can serve as a guide to actual practice. It is suggested that a registry of randomized clinical trials and larger data bases in cardiovascular disease and health care delivery be established. The registry would be a resource for those desiring to model decision making. The registry would contain key words allowing retrieval by modelers accessing the registry and would contain contact information for consideration of possible collaborative work. The initiation of such a registry should contain plans for its evaluation to determine whether the registry itself is a cost-effective tool to encourage the needed research

Status and origin of Egyptian local rabbits in comparison with Spanish common rabbits using mitochondrial DNA sequence analysis

[EN] Mitochondrial DNA (mtDNA) and cytochrome b (cyt b) gene sequences were used to determine the status of genetic diversity and phylogeny for 132 individuals from local rabbit breeds in Egypt and Spain. The Egyptian local rabbit breeds were Egyptian Red Baladi (ERB), Egyptian Black Baladi (EBB) and Egyptian Gabali Sinai (EGS). However, the Spanish local rabbit breed was Spanish common rabbit (SCR). Previous breeds were compared with European Wild Rabbit taken from Albacete, Spain (EWR). A total of 353 mutations, 290 polymorphic sites, 14 haplotypes, 0.06126 haplotype diversity and –1.900 (P<0.05) for Tajima’s D were defined in this study. Haplotype A mostly occurred in 83.3% of Egyptian rabbits and 11.7 % of EWR, while haplotype B occurred in 63.8% of Spanish rabbits and 36.2% of the EGS breed. A total of 47 domestic and wild Oryctolagus cuniculus published sequences were used to investigate the origin and relation among the rabbit breeds tested in this study. The most common haplotype (A) was combined with 44.7% of published sequences. However, haplotype B was combined with 8.5%. Haplotypes of Egyptian, SCR and EWR were scattered in cluster 1, while we found only one EGS haplotype with two haplotypes of EWR in cluster 2. Our results assumed that genetic diversity for ERB, EBB and SCR was very low. Egyptian breeds and SCR were introduced from European rabbits. We found that ERB and EBB belong to one breed.Emam, AM.; Afonso, S.; González-Redondo, P.; Mehaisen, G.; Azoz, A.; Ahmed, N.; Fernand, N. (2020). Status and origin of Egyptian local rabbits in comparison with Spanish common rabbits using mitochondrial DNA sequence analysis. World Rabbit Science. 28(2):93-102. https://doi.org/10.4995/wrs.2020.12219OJS93102282Abrantes J., Areal H., Esteves P.J. 2013. Insights into the European rabbit (Oryctolagus cuniculus) innate immune system: genetic diversity of the toll-like receptor 3(TLR3) in wild populations and domestic breeds. BMC Genet., 14: 73. https://doi.org/10.1186/1471-2156-14-73Achilli A., Olivieri A., Pellecchia M., Uboldi C., Colli L., Al-Zahery N., Accetturo M., Pala M., Kashani B.H., Perego U.A., Battaglia V., Fornarino S., Kalamati J., Houshmand M., Negrini R., Semino O., Richards M., Macaulay V., Ferretti L., Bandelt H.J., Ajmone-Marsan P., Torroni A. 2008. Mitochondrial genomes of extinct aurochs survive in domestic cattle. Curr. Biol., 18: R157-R158. https://doi.org/10.1016/j.cub.2008.01.019Alves J.M., Carneiro, M., Afonso S., Lopes S., Garreau H., Boucher S., Allian D., Queney G., Esteves P.J., Bolet J. and Ferrnand N. 2015. Levels and patterns of genetic diversity and population structure in domestic rabbits. PLoS One 10 (12): e0144687. https://doi.org/10.1371/journal.pone.0144687Bolet G., Brun J.M., Monnerot M., Abeni F., Arnal C., Arnold J., Bell D., Bergoglio G., Besenfelder U., Bosze S., Boucher S., Chanteloup N., Ducourouble M.C., Durand-Tardif M., Esteves P.J., Ferrand N., Gautier A., Haas C., Hewitt G., Jehl N., Joly T., Koehl P.F., Laube T., Lechevestrier S., Lopez M., Masoero G., Menigoz J.J., Piccinin R., Queney G., Saleil G., Surridge A., Van Der Loo W., Vicente J.S., Viudes De Castro M.P., Virag G., Zimmermann, J.M. 2000. Evaluation and conservation of European rabbit (Oryctolagus cuniculus) genetic resources. First results and inferences. In Proc.: 7th World Rabbit Congress, 4-7 July 2000, Valencia, Spain, pp. 281-315.Bollback J.P., Huelsenbeck J.P. 2007. Clonal interference is alleviated by high mutation rates in large populations. Mol. Biol. Evol., 24: 1397-1406. https://doi.org/10.1093/molbev/msm056Bortoluzzi C., Bosse M., Derks M.F.L., Crooijmans R., Groenen M.A.M, Megens H.J. 2019. The type of bottleneck matters: Insights into the deleterious variation landscape of small managed populations. Evol Appl., 13: 330-341. https://doi.org/10.1111/eva.12872.Brook B.W. 2008. Demographics versus genetics in conservation biology. In: Carrol, S.P. and Fox, C.W. (eds). Conservation Biology: Evolution in Action. Oxford University Press: USA. 35-49.Campos, R., Storz, J.F., Ferrand, N. 2012. Copy number polymorphism in the α-globin gene cluster of European rabbit (Oryctolagus cuniculus). Heredity, 108: 531-536. https://doi.org/10.1038/hdy.2011.118Carneiro M., Afonso S., Geraldes A., Garreau H., Bolet G., Boucher S., Tircazes A., Queney G., Nachman M.W., Ferrand N. 2011. The genetic structure of domestic rabbits. Mol. Biol. Evol., 28: 1801-1816. https://doi.org/10.1093/molbev/msr003Carneiro M., Albert F.W., Melo-Ferreira J., Galtier N., Gayral P., Blanco-Aguiar J.A., Villafuerte R., Nachman N.M., Ferrand N. 2012. Evidence for widespread positive and purifying selection across the European rabbit (Oryctolagus cuniculus) genome. Mol. Biol. Evol., 29: 1837-1849. https://doi.org/10.1093/molbev/mss025Christensen N.D., Peng X. 2012. Rabbit genetic and transgenic model. In: The Laboratory Rabbit, Guinea pig, Hamster and other Rodents (Eds. Suckow, M.A., Stevens, K.A. and Wilson, R.P). Elsevier, USA, pp. 165-194. https://doi.org/10.1016/B978-0-12-380920-9.00007-9Christodoulakis M., Golding G.B., Iliopoulos C.S., Pinzón Ardila Y.J., Smyth W.F. 2007. Efficient algorithms for counting and reporting segregating sites in genomic sequences. J. Comput. Biol., 14: 1001-1010. https://doi.org/10.1089/cmb.2006.0136Emam A.M., Afonso, S., Azoz, A., Mehaisen, G.M.K., Gonzalez, P.; Ahmed, N.A., Ferrnand N. 2016. Microsatellite polymorphism in some Egyptian and Spanish common rabbit breeds. In Proc.: 11th World Rabbit Congress, 15-18 June 2016, Qingdao, China. pp: 31-34.Emam A.M., Azoz A., Mehaisen G.M.K., Ferrnand N., Ahmed N.A. 2017. Diversity assessment among native middle Egypt rabbit populations in North upper- Egypt province by microsatellite polymorphism. World Rabbit Sci., 25: 9-16. https://doi.org/10.4995/wrs.2017.5298Ennafaa H., Monnerot M., Gaaied A.E., Mounolou J.C. 1987. Rabbit mitochondrial DNA: preliminary comparison between some domestic and wild animals. Genet. Select. Evol.,19:279-288. https://doi.org/10.1186/1297-9686-19-3-279FAO. 2007. Global plan of action for animal genetic resources and the Interlaken declaration. Available at http://www.fao.org/docrep/010/a1404e/a1404e00.htm. Accessed August 2019.FAO. 2011. Animal production and health guidelines (9), Molecular genetic characterization of animal genetic resources, Commission on genetic resources for food and agriculture. Food and Agriculture Organization of the United Nations. Rome.Fu Y.X., Li W.H. 1993. Statistical tests of neutrality of mutations. Genetics,133: 693-709.Fuller S.J., Wilson, J.C., Mather P.B. 1997. Patterns of differentiation among wild rabbit populations Oryctolagus Cuniculus L. in arid and semiarid ecosystems of North-Eastern Australia. Mol. Eco., 6: 145-153. https://doi.org/10.1046/j.1365-294X.1997.00167.xGaggiotti O.E. 2003. Genetic threats to population persistence. Ann. Zool. Fennici, 40: 155-168. Galal E.S.E., Khalil M.H. 1994. Development of rabbit industry in Egypt. Cahiers Options Méditerranéennes, 8: 43-56.Geraldes A., Ferrand N., Nachman M.W. 2006. Contrasting patterns of introgression at X-linked loci across the hybrid zone between subspecies of the European rabbit (Oryctolagus cuniculus). Genetics, 173, 919-933. https://doi.org/10.1534/genetics.105.054106Ghalayini M, Launay A, BridierNahmias A, Clermont O, Denamur E, Lescat M, Tenaillon O. 2018. Evolution of a dominant natural isolate of Escherichia coli in the human gut over the course of a year suggests a neutral evolution with reduced effective population size. Appl. Environ. Microbiol., 84: e02377-17. https://doi.org/10.1128/AEM.02377-17González-Redondo P. 2007. Estado de las poblaciones y posibilidades de recuperación del conejo doméstico común Español. In Proc.: IV Jornadas Ibéricas de Razas Autóctonas y sus Productos Tradicionales: Innovación, Seguridad y Cultura Alimentarias. Seville (Spain), pp. 367-372.Grimal A., Safaa H.M., Saenz-de-Juano M.D., Viudes-de-Castro M.P., Mehaisen G.M.K., Elsayed D.A.A., Lavara R., Marco Jiménez F., Vicente J.S. 2012. Phylogenetic relationship among four Egyptian and one Spanish rabbit populations based on microsatellite markers. In Proc.: 10th World Rabbit Congress, 3-6 September, 2012, Sharm El-Sheikh, Egypt, pp. 177-181.Guo H., Jiao Y., Tan X., Wang X., Huang X., Huizhe X., Jin H. and. Paterson, A.H. 2019. Gene duplication and genetic innovation in cereal genomes. Genome Res. 29: 261-269. https://doi.org/10.1101/gr.237511.118Guo H., Jiao Y., Tan X., Wang X., Huang X., Jin H., Paterson A.H. Gene duplication and genetic innovation in cereal genomes. Genome Res., 29: 261-269.Gupta A., Bhardwaj A., Supriya, Sharma P., Pal Y., Kumar S. 2015. Mitochondrial DNA- a Tool for Phylogenetic and Biodiversity Search in Equines. J. Biodivers Endanger Species, S1: 006. https://doi.org/10.4172/2332-2543.S1-006Hall S.J.G. 2004. Livestock biodiversity: genetic resources for the farming of the future. Blackwell Science Ltd. Oxford, United Kingdom. 280 pp. https://doi.org/10.1002/9780470995433Jayaraman R. 2011. Hypermutation and stress adaptation in bacteria. J. Genet., 90: 383-391. https://doi.org/10.1007/s12041-011-0086-6Kekkonen J., Brommer J.E. 2014. Reducing the loss of genetic diversity associated with assisted colonization-like introductions of animals. Available at http://www.currentzoology.org/site_media/onlinefirst/downloadable_file/2014/12/01/Kekkonen.pdf. Accessed January 2015.Khalil M.H. 2002. The Baladi Rabbits (Egypt). In: Rabbit genetic resources in Mediterranean Countries. Eds. M. H. Khalil and M. Baselga. Options Mediterranéennes Serie B, 38: 39-50.Kim J.H., Byun M.J., Kim M.J., Suh S.W., Ko Y.G., Lee C.W., Jung K.S., Kim E.S., Yu D.J., Kim W.Y., Choi S.B. 2013. MtDNA diversity and phylogenetic state of Korean cattle breed, Chikso. Asian-Australas. J. Anim. Sci., 26: 163-170. https://doi.org/10.5713/ajas.2012.12499Librado P., Rozas J. 2009. DnaSP v5: a software for comprehensive analysis of DNA polymorphism data. Bioinformatics, 25: 1451-1452. https://doi.org/10.1093/bioinformatics/btp187Long J.R., Qiu X.P., Zeng F.T., Tang L.M., Zhang Y.P. 2003. Origin of rabbit (Oryctolagus cuniculus) in China: evidence from mitochondrial DNA control region sequence analysis. Anim. Genet., 34: 82-87. https://doi.org/10.1046/j.1365-2052.2003.00945.xMartin-Burriel, I., Marcos, S., Osta R., García-Muro, E., Zaragoza, P. 1996. Genetic characteristics and distances amongst Spanish and French rabbit population. World Rabbit Sci., 4: 121-126. https://doi.org/10.4995/wrs.1996.282Ministry of Agriculture and Land Reclamation in Egypt, FAO (2003). First Report on the state of animal Genetic Resources in the Arab Republic of Egypt. FAO, Rome, pp. 23.Monnerot M., Vigne J.D., Biju-Duval C., Casane D., Callou C., Hardy C., Mougel F., Soriguer R., Dennebouy N., Mounolou J. (1994) Rabbit and man: genetic and historic approach. Genet. Select. Evol., 26: 167s-182s. https://doi.org/10.1186/1297-9686-26-S1-S167Mougel F., Gautier A, Queney G., Sanchez M., Dennebouy N., Monnerot M. 2002. History of European rabbit populations in France: advantage and disadvantage of mtDNA. Available at https://www.ncbi.nlm.nih.gov/nuccore/AJ535802 Accessed August 2019.Nguyen N., Brajkovic V., Cubric-Curik V., Ristov S., Veir Z., Szendrő Z., Nagy I., Curik, I. 2018. Analysis of the impact of cytoplasmic and mitochondrial inheritance on litter size and carcass in rabbits. World Rabbit Science, 26: 287-298. https://doi.org/10.4995/wrs.2018.7644Owuor S.A., Mamati E.G., Kasili R.W. 2019. Origin, Genetic Diversity, and Population Structure of Rabbits (Oryctolagus cuniculus) in Kenya. BioMed. Res. Internat., 2019: 7056940. https://doi.org/10.1155/2019/7056940Park G., Pichugin Y., Huang W., Traulsen A. 2019. Population size changes and extinction risk of populations driven by mutant interactors. Phys. Rev., E 99, 022305. https://doi.org/10.1103/PhysRevE.99.022305Peischl S., Excoffier L. 2015. Expansion load: recessive mutations and the role of standing genetic variation. Mol. Ecol., 24: 2084-2094. https://doi.org/10.1111/mec.13154Sakthivel M., Tamilmani G., Abdul Nazar A.K., Jayakumar R., Sankar M., Rameshkumar P., Anikuttan K.K., Samal A.K., Anbarasu M., Gopakumar G. 2018. Genetic variability of a small captive population of the cobia (Rachycentron canadum) through pedigree analyses. Aquaculture, 498: 435-443. https://doi.org/10.1016/j.aquaculture.2018.08.047Schmidt D., Pool J. 2002. The effect of population history on the distribution of Tajima's D statistics. Available at http://www.cam.cornell.edu/~deena/TajimasD.pdf. Accessed March 2019.Schumer M., Xu C., Powell D.L., Durvasula A., Skov L., Holland C., Blazier J.C., Sankararaman S., Andolfatto P., Rosenthal G.G., Przeworski M. 2018. Natural selection interacts with recombination to shape the evolution of hybrid genomes. Science, 360: 656-660 https://doi.org/10.1126/science.aar3684Tamura K., Stecher G., Peterson D., Filipski A., Kumar S. 2013. MEGA6: Molecular Evolutionary Genetics Analysis version 6.0. Mol. Biol. Evol., 30: 2725-2729. https://doi.org/10.1093/molbev/mst197Valvo M., Russo R., Mancuso F.P. 2017. mtDNA diversity in a rabbit population from Sicily (Italy). Turk. J. Zool. 41: 645-653. https://doi.org/10.3906/zoo-1511-53van der Loo W., Mougel F., Sanchez M.S., Bouton C., Castien E., Soriguer R., Hamers R., Monnerot M. 1997. Evolutionary patterns at the antibody constant region in rabbit (Oryctolagus cuniculus): characterization of endemic b-locus haplotypes and their frequency correlation with major mitochondrial gene types in Spain. Gibier Faune Sauvage, 14: 427-449.Wares J.P. 2010. Natural distributions of mitochondrial sequence diversity support new null hypotheses. Evolution 64: 1136-1142. https://doi.org/10.1111/j.1558-5646.2009.00870.xWatson J.P.N., Davis S.J.M. 2019. Shape differences in the pelvis of the rabbit, Oryctolagus cuniculus (L.), and their genetic associations. Available at https://hal.archives-ouvertes.fr/hal-01918838v2 Accessed March 2019.Yu Yeh S., Hsuan Song C., Llu-lin T., Chung Chou C. 2019. The effects of crossbreeding, age, and sex on erythrocyte indices and biochemical variables in crossbred pet rabbits (Oryctolagus cuniculus). Vet. Clin. Pathol., 48: 469-480. https://doi.org/10.1111/vcp.12775Zaragoza P., Arana A., Zaragoza I., Amorena B. 1987. Blood biochemical polymorphisms in rabbits presently bred in Spain: Genetic variation and distances amongst populations. Aust. J. Biol. Sci., 40: 275-286. https://doi.org/10.1071/BI987027

Diversity assessment among native Middle Egypt rabbit populations in North Upper-Egypt province by microsatellite polymorphism

[EN] Safeguarding biodiversity is an important goal for animal production in developed countries. This study investigated genetic diversity among native Middle-Egypt rabbit (NMER) populations in North Upper-Egypt province by using microsatellite polymorphism. Nineteen microsatellite loci were used in the study and an area of 231 km was surveyed, as native rabbits covered 14 points belonging to four Northern Upper Egypt governorates (South Giza, Fayoum, Beni Suef and Minya). Standard statistical parameters of genetic variability within and between populations confirmed that the highest genetic diversity was found towards the south. Among NMER populations, the mean number of alleles per locus was lowest in South Giza (5.32), while it was highest in Minya (6.00). This study found that NMER featured a high number of private alleles ranging between 7 and 11 (mean value was 10.5). Results also showed a high genetic diversity in NMER populations and that heterozygosity ranged between 0.384 and 0.445, strongly indicating extensive genetic variation in the NMER populations. The mean values of observed and expected heterozygosity were 0.405 and 0.612, respectively. Factorial correspondence analysis and neighbour joining trees (NJ) showed 2 main NMER rabbit groups: the Northern group (South Giza and Fayoum) and the Southern group (Beni Suef and Minya). All populations showed a high percentage of assignment in this study (0.913 to 0.946). The structure analysis showed that each population existed in separate clusters. This research provides an overview of genetic diversity of NMER populations in the Northern Upper Egypt province for the first time. In conclusion, results of this study could be used to designate priorities for conservation of NMER populations.Emam, A.; Azoz, A.; Mehaisen, G.; Ferrand, N.; Ahmed, N. (2017). Diversity assessment among native Middle Egypt rabbit populations in North Upper-Egypt province by microsatellite polymorphism. World Rabbit Science. 25(1):9-16. doi:10.4995/wrs.2017.5298.SWORD916251Abdel-Mawgood A. L. 2012. DNA Based Techniques for Studying Genetic Diversity. In Caliskan M. (Eds.) Genetic Diversity in Microorganisms, 95-122, InTechRijeka, Croatia.Abel-Kafy E. M., Shabaan H. M. A., Azoz, A. A. A., El-Sayed A. F. M., Abdel-Latif A. M. 2011. Descriptions of native rabbit breeds in Middel-Egypt. In Proc.: 4th Egyptian Conference of Rabbit Science. 30th October, 2011, Giza, Egypt.Badawy A.G. 1975. Rabbit Raising, 2nd ed. Central Administration for Agricultural Culture, Ministry of Agriculture, Egypt (in Arabic).Ben Larabi M., San-Cristobal M., Chantry-Darmon C., Bolet G. 2012. Genetic diversity of rabbit populations in Tunisia using microsatellites markers. In Proc.: 10th World Rabbit Congress, 3-6 September, 2012, Sharm El-Sheikh, Egypt.Bolet G., Brun J.M., Monnerot M., Abeni F., Arnal C., Arnold J., Bell D., Bergoglio G., Besenfelder U., Bosze S., Boucher S., Chanteloup N., Ducourouble M.C., Durand-Tardif M., Esteves P.J., Ferrand N., Gautier A., Haas C., Hewitt G., Jehl N., Joly T., Koehl P.F., Laube T., Lechevestrier S., Lopez M., Masoero G., Menigoz J.J., Piccinin R., Queney G., Saleil G., Surridge A., Van Der Loo W., Vicente J.S., Viudes De Castro M.P., Virag G., Zimmermann J.M. 2000. Evaluation and conservation of European rabbit (Oryctolagus cuniculus) genetic resources. First results and inferences, In Proc.: 7th World Rabbit Congress, 4-7 July, 2000, Valencia, Spain, 281-315.Emam A.M., Afonso S., Azoz A.A.A., González-Redondo P., Mehaisen G.M.K., Ahmed N.A., Ferrand N. 2016. Microsatellite polymorphism in some Egyptian and Spanish common rabbit breeds. In Proc.: 11th World Rabbit Congress, 15-18 June, 2016, Qingdao, China.El-Hentati H., Mhamdi N., Ben Hamouda M., Chriki A. 2013. Analysis of genetic variability within Tunisian Barbarine and Western thin Tail sheep using RAPD-PCR Method. Life Sci. J., 10: 2003-2009.EVANNO, G., REGNAUT, S., & GOUDET, J. (2005). Detecting the number of clusters of individuals using the software structure: a simulation study. Molecular Ecology, 14(8), 2611-2620. doi:10.1111/j.1365-294x.2005.02553.xFAO. 2007. The state of the world's animal genetic resources for food and agriculture, edited by Rischkowsky and Pilling. Rome.Fuller, S. J., Wilson, J. C., & Mather, P. B. (1997). Patterns of differentiation among wild rabbit populations Oryctolagus cuniculus L. in arid and semiarid ecosystems of north‐eastern Australia. Molecular Ecology, 6(2), 145-153. doi:10.1046/j.1365-294x.1997.00167.xGalal E.S.E., Khalil M.H. 1994. Development of rabbit industry in Egypt. Options Méditerranéennes, Series Cahiers, 8: 43-56.Grimal A., Safaa H.M., Saenz-de-Juano M.D., Viudes-de-Castro M.P., Mehaisen G.M.K., Elsayed D.A.A., Lavara R., Marco-Jiménez F., Vicente J.S. 2012. Phylogenetic relationship among four Egyptian and one Spanish rabbit populations based on microsatellite markers. In Proc.: 10th World Rabbit Congress, 3-6 September, 2012, Sharm El-Sheikh, Egypt.Ormandy E.H., Dale J., Griffin G. 2011. Genetic engineering of animals: Ethical issues, including welfare concerns. Can. Vet. J., 52: 544-550.Pritchard J.K., Stephens M., Donnelly P. 2000. Inference of population structure using multilocus genotype data. Genetics, 155: 945-959

Surface modified coals for enhanced catalyst dispersion and liquefaction. Quarterly report, 1996

The aim of this work is to enhance catalyst loading and dispersion in coal for improved liquefaction by preadsorption of surfactants onto coal. The application of surfactants to coal beneficiation and coal-water slurry preparation is well known. However, the effects of surfactants on catalyst loading and dispersion prior to coal conversion processes have not been investigated. The current work is focused on the influence of the cationic surfactant dodecyl dimethyl ethyl ammonium bromide (DDAB) and sodium dodecyl sulfate (SDS, anionic) on the surface properties of a bituminous coal and its molybdenum and iron uptake from solution. In the previous report, it was shown that molybdenum loading onto the coal was enhanced by preadsorption of DDAB. The optimum concentration of this surfactant for effective adsorption of molybdenum at the natural pH of the coal slurry has been determined to be in the 0.1 to 0.25 M range. Preadsorption of SDS onto the coal was found to increase the uptake of iron by the coal; iron loading increased with increase in the concentration of the catalyst precursor. This observation is attributed to the increase in the negative surface charge properties of the coal with increase in the concentration of the surfactant. The results of the study show that DDAB enhances the adsorption of molybdenum whereas SDS is more effective for iron loading onto Illinois No. 6 (DECS-24) coal

The role of catalyst precursor anions in coal gasification. Final technical report, September 1991--June 1994

The utilization of coal is currently limited by several factors, including the environmental impacts of coal use and the lack of cost-effective technologies to convert coal into useful gaseous and liquid products. Several catalysts have been evaluated for coal gasification and liquefaction. The activities of the catalysts are dependent on many factors such as the method of catalyst addition to the coal and the catalyst precursor type. Since catalyst addition to coal is frequently conducted in aqueous solution, the surface chemistry of colloidal coal particles will be expected to exert an influence on catalyst uptake. However, the effects of the various coal gasification catalyst precursors on the interfacial properties of coal during catalyst loading from solution has received little attention. The aim of this study is to ascertain the influence of the metal salts (i): calcium acetate (Ca(OOCCH{sub 3}){sub 2}), calcium chloride (CaCl{sub 2}) or calcium nitrate (Ca(NO{sub 3}){sub 2}) and (ii): potassium acetate (KOOCCH{sub 3}), potassium chloride (KCl), potassium nitrate (KNO{sub 3}), potassium carbonate (K{sub 2}CO{sub 3}) and potassium sulfate (K{sub 2}SO{sub 4}) on the electrokinetic and adsorptive properties of coal and determine the relationship, if any, between coal surface electrokinetic properties, and catalyst loading and eventually its effects on the reactivities of coal chars

Surface modified coals for enhanced catalyst dispersion and liquefaction. Semiannual progress report, September 1, 1995--February 29, 1996

The aim of this work is to enhance catalyst loading and dispersion in coal for improved liquefaction by preadsorption of surfactants onto coal. The application of surfactants to coal beneficiation and coal-water slurry preparation is well known. However, the effects of surfactants on catalyst loading and dispersion prior to coal liquefaction have not been investigated. The current work is focused on the influence of the cationic surfactant dodecyl dimethyl ethyl ammonium bromide (DDAB) and sodium dodecyl sulfate (SDS, anionic) on the surface properties of a bituminous coal and its molybdenum uptake from solution. The results show that DDAB created positively charged sites on the coal and increased molybdenum loading compared to the original coal. In contrast, SDS rendered the coal surface negative and reduced molybdenum uptake. The results show that efficient loading of molybdenum catalyst onto coal can be achieved by pretreatment of the coal with dodecyl dimethyl ethyl ammonium bromide

Proceedings of the European Workshop on nondestructive evaluation of polymers and polymer matrix composites Portugal Sep. 4 - 5, 1984./ Ashbee

hal tak beraturan.: ill.; 24 cm