Log in

Relevant bibliographies by topics / Acacia senegal

Contents

Journal articles
Dissertations / Theses
Books
Book chapters

Academic literature on the topic 'Acacia senegal'

Author: Grafiati

Published: 4 June 2021

Last updated: 26 February 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Acacia senegal.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Acacia senegal"

1

Emmanuel, Jovine, and Joseph Buchweishaija. "Temperature Effects on the Corrosion Inhibition of Mild Steel in Sulfuric Acid Solution by Acacia senegal Gum with Halide Ions." Tanzania Journal of Science 47, no. 5 (December 1, 2021): 1588–95. http://dx.doi.org/10.4314/tjs.v47i5.9.

Full text

Abstract:

The effects of temperature on the inhibitive effect of naturally occurring Acacia senegal gum exudate on the corrosion of mild steel in sulfuric acid was studied between 35 and 70 °C using electrochemical impedance spectroscopy and potentiodynamic polarization methods. Findings showed that Acacia senegal gum exudate decreases the corrosion rate of mild steel. The inhibition efficiency declined with raising temperature above 35 °C. The increase in the corrosion rate with increasing temperature was observed for both uninhibited and inhibited systems. Addition of halide ions to the Acacia senegal gum exudate solution enhanced the corrosion inhibition efficiency because of synergistic effects, achieving higher performance with iodide ions as compared to bromide ions. However, the synergistic effects declined above 35 °C up to 70 °C due to temperature effects. It has been observed that increasing temperature adversely affected inhibition efficiencies of both Acacia senegal gum exudate and the synergy between Acacia senegal gum exudate and halide ions. Corrosion rates of mild steel, inhibition efficiencies of Acacia senegal gum exudate and the synergistic effects of halide ions from polarization and impedance measurements were consistent. Keywords: temperature, corrosion, mild steel, synergistic effects, Acacia senegal, gum exudate.

APA, Harvard, Vancouver, ISO, and other styles

2

Ahallil, H., M. Y. Maskat, A. Abdullah, and S. R. Sarbini. "The effect of Acacia senegal as potential prebiotic on obese gut microbiota." Food Research 4, no. 3 (January 27, 2020): 814–22. http://dx.doi.org/10.26656/fr.2017.4(3).350.

Full text

Abstract:

Gut microbiota is able to affect body weight by fermenting dried fibers and generating short chain fatty acids (SCFA). Acacia senegal is an edible dried which might have potential prebiotic activity. The aim of this study was to investigate the effect of Acacia senegal as potential prebiotic on the composition and activity of human colonic microbiota of obese healthy subjects. In order to identify a potential prebiotic effect of Acacia senegal on obese individuals, anaerobic, pH-controlled batch cultures system was applied. The growth of different microbes and the concentration of lactic acid and short chain fatty acids were studied at 0, 6, 12, 24 and 36 hrs using fluorescent in situ hybridization (FISH) and HPLC respectively. The results showed that Acacia senegal was able to simulate the microbiota population since it significantly increased (P>0.05) the population of Bifidobacterium and decreased the population of Clostridium. Moreover, the supplement of Acacia senegal to the models significantly modulate short-chain fatty acid concentration. These findings clearly identified Acacia senegal as an additional contributing factor to the gut microbiota of obese subject and suggest that Acacia senegal could be an interesting supplement for obese human which might help to control obesity.

APA, Harvard, Vancouver, ISO, and other styles

3

Emmanuel, Jovine, and Joseph Buchweishaija. "Synergistic effects of halide ions and Acacia senegal gum on the corrosion inhibition of mild steel in sulfuric acid solution." Tanzania Journal of Science 47, no. 2 (May 19, 2021): 686–97. http://dx.doi.org/10.4314/tjs.v47i2.24.

Full text

Abstract:

The synergistic effects of halide ions, Br– and I– and Acacia senegal gum exudates on the corrosion inhibition of mild steel in 0.5 M sulfuric acid solution has been investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy techniques. Results showed that Acacia senegal gum exudate moderately reduces the corrosion rate of mild steel. The inhibition efficiencies on mild steel electrodes increased with increase in gum exudate concentrations up to 300 ppm, corresponding to the inhibition efficiency of about 43% and its inhibition efficiency increased up to 81.6% with addition of halide ions due to synergistic effects. The enhancement effect of the halide ions was higher with iodide than with bromide ions. The synergism parameter, S1, evaluated was greater than unity, consistent with synergistic effect. The adsorption of Acacia senegal gum on the mild steel surface obeyed Langmuir’s adsorption isotherm. The results obtained, i.e., corrosion rates of mild steel, inhibition efficiencies of Acacia senegal gum exudates and the synergistic effects of Acacia senegal gum exudates and halides from polarization and impedance measurements were in good agreement. Keywords: corrosion, inhibition, mild steel, synergistic effect, Acacia senegal, gum exudate

APA, Harvard, Vancouver, ISO, and other styles

4

Salma Farah Abdelhay Ahmed, Yahia Ibrahim Mohammed Abutaba, and Seif Adin Dawina Abdullah Fragallah. "Effect of levels salinity water on seedling growth of Acacia senegal at the Nursery, North Kordofan state, Sudan." GSC Advanced Research and Reviews 14, no. 1 (January 30, 2023): 060–68. http://dx.doi.org/10.30574/gscarr.2023.14.1.0350.

Full text

Abstract:

This study was conducted in Shikan nursery, Elobied, North Kordofan, from three sources of Acacia senegal seeds (Al-Rahad, Al-Aabasia and Um- Keradem) at January 2022. This study aims to determent the effect of saline water levels on growth of Acacia senegal seedlings. Different salt water levels were used to irrigate seedlings. The response to salt water stress at general level was good with appearance of significant differences at beginning of experiment and these differences disappeared at end of experiment. This indicates that Acacia senegal seedlings were more tolerant of salt water stress to the level of 2898 ms/cm total dissolved salts (T.D.S), can be used for irrigation, especially for Acacia senegal seedlings with a ph between (7.1-8.4). To reduce seedling death, low salinity levels can be relied upon.

APA, Harvard, Vancouver, ISO, and other styles

5

Cui, Steve W., Glyn O. Phillips, Barbara Blackwell, and John Nikiforuk. "Characterisation and properties of Acacia senegal (L.) Willd. var. senegal with enhanced properties (Acacia (sen) SUPERGUM™): Part 4. Spectroscopic characterisation of Acacia senegal var. senegal and Acacia (sen) SUPERGUM™ arabic." Food Hydrocolloids 21, no. 3 (May 2007): 347–52. http://dx.doi.org/10.1016/j.foodhyd.2006.05.009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

SANTRA, A., and S. A. KARIM. "Nutritional evaluation of some Indian tree pods for livestock feeding." Indian Journal of Animal Sciences 90, no. 11 (April 7, 2021): 1535–40. http://dx.doi.org/10.56093/ijans.v90i11.111567.

Full text

Abstract:

The objective of this study was to evaluate promising tree pods for feeding to the livestock particularly for the small ruminants. Out of eight tested tree pods, seven tree pods, i.e. White siris (Albizia procera), Siris (Albizia lebbeck), White kheri (Acacia senegal), Babul (Acacia arabica), Khejri (Prosopis cineraria), Vilayati babul (Prosopis juliflora) and Sajna (Moringa oleifera) were collected from semiarid region of Rajasthan while one tree pods e.g., Jungle jalebi (Enterolobium timoba) was collected from Dehradun, Uttrakhand, India. Most of the tree pods were rich in CP content. On an average, OM, CP, EE, NDF, ADF and cellulose content of these tree pods were found to be 91.1, 16.7, 2.5, 43.3, 34.7 and 25.4% on DM basis, respectively. Rumen protozoal number decreased due to inclusion of Enterolobium timoba tree pods in the incubation media. The TVFA and propionate production were higher for Acacia Senegal, Acacia arabica tree pods followed by Moringa oleifera tree pods while ammonia nitrogen concentration was lower due to inclusion of Enterolobium timoba tree pods in the incubation media. All the tested tree pods had no effect on xylanase, Î²-glucosidase and amylase enzyme activity. However, specific activity of carboxymethyl cellulase enzyme reduced due to addition of Enterolobium timoba tree pods in the incubation medium. Highest IVDMD was observed for Acacia arabica tree pods followed by Acacia senegal and Moringa oleifera tree pods. The results indicated that Acacia arabica, Acacia senegal and Moringa oleifera are good tree pods for feeding to the animals.

APA, Harvard, Vancouver, ISO, and other styles

7

Mbayngone, Elisée, Serge Mélom, Ali Brahim Béchir, and Pierre Marie Mapongmetsem. "Structure et productivité en gomme des peuplements à Acacia senegal (L) Willd. et Acacia seyal Del. de Massenya au Tchad." Flora et Vegetatio Sudano-Sambesica 20 (December 20, 2017): 3–11. http://dx.doi.org/10.21248/fvss.20.49.

Full text

Abstract:

La connaissance du potentiel et de la productivité d'une ressource est une donnée nécessaire à l'élaboration d'une bonne politique de sa gestion. La structure et la productivité des peuplements à Acacia seyal Del. et à Acacia senegal (L) Willd.ont été étudiées dans les formations naturelles de Massenya au Tchad. Sur la base de 32 placeaux de 900 m2, le diameter et la hauteur de tous les individus d’espèces ligneuses ont été mesurés. Pour des espèces adultes à port arbustif, le diameter est mesuré à 50 cm du sol. Les individus juvéniles sont simplement comptés et ranges en classe de hauteur. L’étude de la structure des peuplements et de deux espèces d’Acacia a été réalisée à travers le nombre de tiges à l’hectare et les classes de diamètre. L’Indice de Valeur d’Importance (IVI) a été utilisée pour apprécier la prédominance des espèces sur le site. La productivité des peuplements en gomme a été évaluée en fonction de la production moyenne d’un arbre qui était de 250 g. Les peuplements à Acacia de Massenya sont très denses (619 ± 269 tiges/ha), mais à surface terrière faible (7,10 ± 1,20 m²/ha) due à un grand nombre d’individus de petit diamètre (11,1 ± 2,2 cm). Ce sont des peuplements généralement arbustif (hauteur de 5,2 ± 0,9 m) avec un bon potentiel de juvéniles (408 ± 267 tiges/ha) pouvant se régénérer naturellement. Toutefois, Acacia seyal semble plus apte à coloniser d’autres milieux qu’Acacia senegal. Sur les sept espèces qui prédominent sur le site, Acacia seyal et Acacia senegal réalisent des IVI plus élevés (respectivement 79 et 54). Les espèces à bon potentiel de régénération sont Acacia seyal (65 ± 8 juv./ha), Acacia senegal (58 ± 10 juv./ha) et Guiera senegalensis (51 ± 8 juv./ha). La production annuelle de gomme est estimée à 56 ± 6 kg/ha de gomme friable (à Acacia seyal) et 41 ± 5 kg/ha de gomme dure (à A. senegal).

APA, Harvard, Vancouver, ISO, and other styles

8

Elgailani, Isam Eldin Hussein, and Christina Yacoub Ishak. "Determination of Tannins of Three Common Acacia Species of Sudan." Advances in Chemistry 2014 (September 17, 2014): 1–5. http://dx.doi.org/10.1155/2014/192708.

Full text

Abstract:

The objective of this study is to analyze and compare tannins of three common Acacia species of Sudan, since vegetable tannins are important in leather industry. Acacia nilotica and Acacia seyal samples were collected from Sunt Forest in Khartoum State, while Acacia senegal samples were collected from the Debabat Forest in South Kordofan State. Bark samples from bulk collections of the three Acacia species were extracted with boiled deionized water. The amount of tannins present in these bulk samples was determined by Folin-Denis method for total phenolic materials, followed by precipitation with hide-powder. The difference between the amount of phenolic materials present before and after addition of hide-powder represents the amount of tannins present. The percentage of tannins in the leaves, bark, and mature and immature fruits of collections of individuals of Acacia species was estimated; mature and immature fruits of Acacia nilotica contain tannins (22.15% and 22.10%, resp.). The leaves of Acacia nilotica and Acacia seyal contain tannins (11.80% and 6.30%, resp.). The barks of Acacia seyal, Acacia nilotica, and Acacia senegal contain tannins (12.15%, 10.47%, and 3.49%, resp.).

APA, Harvard, Vancouver, ISO, and other styles

9

Omondi, Stephen F., O. G. Dangasuk, D. W. Odee, S. Cavers, and D. P. Khasa. "Cross-amplification and Characterization of Polymorphic Microsatellite Markers From Acacia (Senegalia) mellifera and Acacia brevispica to Acacia senegal (L.) Willd." Silvae Genetica 59, no. 1-6 (December 1, 2010): 285–88. http://dx.doi.org/10.1515/sg-2010-0040.

Full text

Abstract:

Abstract Seven polymorphic microsatellite markers isolated from Acacia brevispica and Acacia mellifera were successfully cross-amplified in Acacia senegal. The loci were surveyed for polymorphism using 30 samples. Allelic diversity ranged from 4 (Ame02, Ab06 and Ab18) to 13 (Ab26) per locus. The expected heterozygosity (HE) ranged from 0.543 (Ame02) to 0.868 (Ab26) while observed heterozygosity (HO) ranged from 0.516 (Ame05) to 0.800 (Ame03). Cross-amplification of these loci represents a potential source of co-dominant markers and will be useful in the study of genetic diversity, structure, gene flow and breeding systems of this important Acacia species.

APA, Harvard, Vancouver, ISO, and other styles

10

Halidou, Djabri Hassimiou, Maman Manssour Abdou, and Zoubeirou Alzouma Mayaki. "Caractérisation du sol du site dégradé de Sakey koira Tegui au Niger pour un meilleur reboisement avecAcacia senegal." International Journal of Biological and Chemical Sciences 14, no. 4 (August 17, 2020): 1470–78. http://dx.doi.org/10.4314/ijbcs.v14i4.24.

Full text

Abstract:

La dégradation des sols résultants des facteurs climatiques et anthropiques constitue l’un des problèmes majeurs de l’agriculture au Niger. En réponse à ce phénomène, les agroécosystèmes s’adaptent à travers la mise en oeuvre des techniques de gestion intégrée des eaux et des sols dont notamment le reboisement des terres dégradées. C’est ainsi que cette étude a été menée avec pour objectif de caractériser le sol dégradé du site de Sakey koira Tegui en vue d’un meilleur reboisement avec Acacia senegal. A cet effet, des profils pédologiques ont été ouverts et décrits suivant la topo-séquence du site. Des échantillons de sol ont été prélevés au niveau de chaque profil et analysés au laboratoire. Les résultats ont montré que la texture de sols est de type sableuse (72,32%) et limoneuse (45%). Quant aux caractéristiques chimiques des sols, le pH est acide variant de 5,1 à 5,53 sur l’ensemble des horizons avec une conductivité électrique de l’ordre de 13, 00 à 33, 00 μs/cm. Ces résultats montrent que ce sol de faible fertilité chimique, avec une prédominance sableuse pourrait être récupéré et reboisé avec Acacia senegal, sol de prédilection de cette espèce. Mots clés : caractéristiques chimiques, textures, terres dégradées, Acacia senegal, Niger. English Title: Soil characterization of the degraded site of Sakey koira Tegui in Niger for better reforestation with Acacia senegalSoil degradation resulting from climatic and anthropogenic factors is one of the major problems of agriculture in Niger. In response to this phenomenon, agro-ecosystems are adapting through the implementation of integrated water and soil management techniques, including reforestation of degraded land. Thus, this study was conducted with the objective of characterizing the degraded soil of the Sakey koira Tegui site for better reforestation with Acacia senegal. To this end, soil profiles were opened and described according to the topo-sequence of the site. Soil samples were taken from each profile and analysed in the laboratory. The results showed that the soil texture is sandy (72.32%) and silty (45%). As for the chemical characteristics of the soils, the pH is acidic ranging from 5.1 to 5.53 over all horizons with an electrical conductivity of 13.00 to 33.00 μs/cm. These results show that this soil of low chemical fertility, with a sandy predominance, could be recovered and reforested with Acacia senegal, the soil of predilection of this species.Keywords: Chemical characteristics, textures, degraded soils, Acacia senegal, Niger.

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Acacia senegal"

1

Jibo, Abdullahi Umar. "Variation in drought tolerance and morphological plasticity among two provenances of Acacia senegal (Senegalia senegal) seedling in North Eastern Nigeria." Thesis, University of Aberdeen, 2015. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=227119.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Osman, Mohamed Elmubarak. "Fractionation and characterisation of gum from Acacia senegal." Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336168.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Hamouda, Yasir. "Factors affecting the quality of Acacia senegal gums." Thesis, University of Chester, 2017. http://hdl.handle.net/10034/620895.

Full text

Abstract:

Gum arabic is a natural gummy exudate from acacia trees and exhibits natural built-in variations commonly associated with hydrocolloids. This study is concerned with the determination of factors which could influence its properties and functionality. These factors include origin (location, soil type, rainfall), different collections, age of the trees and storage condition. Previous studies acknowledged the influence of some of these factors but somehow lack providing definitive answers to questions being asked by the end user and required for the development of Gum arabic industry in Sudan. Local knowledge as well as the various stages of gum collection and processing were reviewed in order to provide a clear background and the justification for the experimental design. In this study samples were collected from six plantations located in the west and east regions in Sudan. Samples were collected from trees of different age (5, 10, 15 and 20 years old) and also from different picking interval (1-4). Each sample was divided into three portions (UK, Khartoum and Port Sudan) and stored for 5 years in order to determine the effect of the respective location. Various analytical parameters (% loss on drying, Optical rotation, % protein, intrinsic viscosity, molecular weight and molecular weight distribution) were measured to fully characterise the gum samples and to determine their functionality (emulsification). The results obtained for all samples were consistent with those previously reported in the literature (see Chapter 4). The only exception, identified in a number of samples from the western region, is the high proportion (~30%) of high molecular weight fraction termed arabinogalactan-protein complex (AGP). The results clearly demonstrated significant variations between plantations located in western region compared with the eastern region. However, the variations between the plantations within the same region are statistically not significant. High values of % protein, viscosity, Mw and % AGP were obtained from the 1st pick, from both regions, and then significantly decreased thereafter to the fourth pick. Samples from west region in Sudan, from 1st and 2nd pick and from tree age (15) years gave the highest viscosity, molecular weight, % AGP and superior emulsification performance compared to other samples from different tree ages. The regression statistical analysis for the physiochemical properties correlation with emulsification performance demonstrated the role of % AGP to be the most influential factor followed by viscosity. The major finding of this study is the effect of storage condition on the properties and functionality of Acacia senegal. An increase in the molecular weight for all stored samples (for 5 years) irrespective of region was evident and statically significant. However, this increase was more prominent for samples from the western region compared to the eastern region. The AGP fraction was increased by the storage treatment up to 40% in Port-Sudan, 20% in Khartoum-Sudan and 15% in UK. The result clearly demonstrated that the temperature and humidity are the crucial factors to induce the natural maturation process in acacia gums. Statistical analysis (linear regression) suggested statistically significant models and equations to predict and explain the variations in the physiochemical and functional properties based on the environmental factors, picking set and age of the tree.

APA, Harvard, Vancouver, ISO, and other styles

4

Sprent, JI, DW Odee, and FD Dakora. "African legumes: a vital but under-utilized resource." Oxford University Press, 2010. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001196.

Full text

Abstract:

Abstract Although nodulated legumes have been used by indigenous peoples in Africa for centuries, their full potential has never been realized. With modern technology there is scope for rapid improvement of both plant and microbial germplasm. This review gives examples of some recent developments in the form of case studies; these range from multipurpose human food crops, such as cowpea (Vigna unguiculata (L.) Walp.), through to beverages (teas) that are also income-generating such as rooibos (Aspalathus linearis (Burm. f.) R. Dahlgren, honeybush (Cyclopia Vent. spp.), and the widely used food additive gum arabic (Acacia senegal (L.) Willd.). These and other potential crops are welladapted to the many different soil and climatic conditions of Africa, in particular, drought and low nutrients. All can nodulate and fix nitrogen, with varying degrees of effectiveness and using a range of bacterial symbionts. The further development of these and other species is essential, not only for African use, but also to retain the agricultural diversity that is essential for a changing world that is being increasingly dominated by a few crops such as soybean.

APA, Harvard, Vancouver, ISO, and other styles

5

McDougal, Fiona Janet. "Studies on gum exudates, with particular reference to gum Arabic (Acacia senegal) and other Acacia species." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/11112.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Bérépion, Bastien. "Incidence de la composition chimique et des propriétés physico-chimiques des gommes en acacia sur leurs propriétés en émulsion." Le Havre, 2011. http://www.theses.fr/2011LEHA0013.

Full text

Abstract:

La gomme acacia est un exsudat de l’Acacia senegal var senegal couramment utilisée dans l’industrie agroalimentaire et pharmaceutique comme émulsifiant et stabilisant (E414). Cette thèse, réalisée en collaboration avec l’entreprise Allan &Robert, étudie les relations entre la composition chimique, les propriétés physico-chimiques, les propriétés fonctionnelles et les conditions environnementales de synthèse et de récolte des gommes acacia. L’étude de gommes brutes montre que l’origine géographique et les conditions de stockage post-récolte peuvent influencer la composition chimique et les propriétés physico-chimiques des gommes. Nous avons également confirmé le rôle important de la fraction AGP dans les propriétés en émulsion, en précisant l’importance du pourcentage d’AGP pour les propriétés émulsifiantes, l’importance de la proportion d’acides aminés aromatiques dans cette fraction pour la stabilité des émulsions et l’impact négatif des agrégats sur les propriétés en émulsion. Il semble également qu’il y ait un lien entre qualité des émulsions et pourcentage de protéines présent dans la gomme. Nous avons également montré que le procédé d’atomisation pouvait avoir une influence sur les propriétés physico-chimiques et fonctionnelles des gommes
Acacia gum is an exudate from Acacia senegal var senegal commonly used in food and pharmaceutical industry as emulsifier and stabilizer (E414). The aim of this thesis, in partnership with Allan & Robert, was to study the relationship between chemical composition, physic-chemical properties, functional properties and environmental conditions of acacia gums synthesis and harvest. At first, studying raw gums show the influence of geographic origin and post-harvest storage condition on the acacia gums chemical composition and physic-chemical properties. Then, we confirm the important role of AGP fraction in emulsions properties into correlating the AGP percent with the emulsifying properties, the aromatic amino acid proportion in the fraction with the emulsion stability and the aggregates negative effect on the emulsion properties. Furthermore, a relation appears between emulsions quality and protein percent in gums. Finally, we highlighted the atomization process influence on physic-chemical and functional properties of acacia gums

APA, Harvard, Vancouver, ISO, and other styles

7

N'Diaye, Ibrahima. "Etude expérimentale sur la propagation d'acacias gommiers." Aix-Marseille 3, 1992. http://www.theses.fr/1992AIX30046.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Schmitt, Christophe. "Étude de la coacervation complexe entre la bêta-lactoglobuline et la gomme d'acacia en solution aqueuse." Vandoeuvre-les-Nancy, INPL, 2000. http://docnum.univ-lorraine.fr/public/INPL_T_2000_SCHMITT_C.pdf.

Full text

Abstract:

L’influence de la concentration totale en bio polymères et de la polydispersité sur la formation et la stabilité de coacervats a été étudiée dans un mélange bêta-lactoglobuline/gomme d'acacia/eau. Les mélanges de bêta-lactoglobuline (bêta -lg) native ou agrégée (56% d'agrégats insolubles à Ph 4,75) et de gomme d'acacia à des Ph compris entre 3,6 et 5,0 sont caractérisés par une séparation de phase par coacervation complexe. Une concentration totale élevée en bio polymères limite l'influence du ph et du ratio de mélange protéine : polysaccharide sur la formation des coacervats dans les deux systèmes. En revanche, une forte polydispersité de la beta-lg augmente l'aire de la zone biphasique des diagrammes de phases ternaires obtenus à Ph 4,2. Des coacervats et des précipités sont obtenus en présence d'agrégats de bêta-lg. Seuls des coacervats sont visibles avec la bêta-lg native. Leur taille est contrôlée par les agrégats protéiques interagissant spécifiquement avec une fraction de la gomme d'acacia. La structure des coacervats est caractérisée par une vacuolisation issue d'une coalescence partielle des plus petits coacervats. Après interaction avec la gomme d'acacia, des mesures de dichroisme circulaire indiquent une modification de la structure en hélice alpha de la bêta-lg, caractérisée par une densité de charge positive. La stabilité et la structuration des coacervats formes résultent d'un équilibre entre des phénomènes de floculation, coalescence et sédimentation des coacervats comme indique par des mesures de diffusion de la lumière en milieu turbide et de microscopie confocale à balayage laser. L’étude cinétique de la structuration des mélanges bêta -lg/gomme d'acacia/eau par diffusion de la lumière aux petits angles révèle des phénomènes de diffusionnels et hydrodynamiques responsables de la croissance des domaines structuraux. Dans certains cas, la cinétique de coacervation complexe peut être décrite par le modèle théorique de décomposition spinodale.

APA, Harvard, Vancouver, ISO, and other styles

9

Schmitt, Marjorie. "Étude du comportement tribologique de revêtements diamants obtenus par procédé flamme." Vandoeuvre-les-Nancy, INPL, 2000. http://www.theses.fr/2000INPL127N.

Full text

Abstract:

Les résultats obtenus durant les trois années de thèse concernent le comportement tribologique de revêtements diamant obtenus par procédé flamme, en fonction de divers paramètres: contreface, environnement, charge normale, orientation cristalline. Une étude préliminaire a abouti aux conclusions suivantes: les rayures dues aux passages des diamants sont visibles même à faible charge; une graphitisation apparaît à forte charge sous oxygène; les tension superficielles jouent un rôle important sous vapeur d'eau à faible charge. Il a également été montré que le coefficient de frottement mesuré n'est pas typique du comportement réel du diamant, mais représente plutôt le couple (diamant + transfert) / (disque + débris d'usure). L'influence de l'orientation cristalline a ensuite été traitée mettant ainsi divers phénomènes en évidence: les transferts préférentiels du disque vers le pion; les différents types d'indentations sous oxygène; l'évolution des revêtements diamant au cours du frottement: déterioration des cristaux, transformation Sp3 -> Sp2. Une étude des couples diamant/alliages aluminium a ensuite été amorcée, concernant plus précisément le rôle des oxydes sur le processus de coupe et la nature du transfert. Enfin, une simulation du contact pion revêtu diamant/disque a été menée en parallèle : cette modélisation a permis d'évaluer la charge critique évitant la décohésion diamant-substrat, phénomène particulièrement important pour les outils de coupe revêtus
Results obtained during these three years of PhD deal with the tribological behaviour of diamond coatings obtained by flame process, and its variations with various parameters : the nature of the counterface, the environment, the applied normalload, the crystals orientation. A preliminary study led to the following conclusions: the scratch due to the diamonds tips motion appeared even at low load ; a graphitisation phenomenon happened at high load under oxygen ; the superficial tension forces played an important part under water vapour at low load. It was also shown that the measured friction coefficient is not typical of the real diamond behaviour, but rather characterised the (diamond + transfer) / (disc + wear debris) couple. The influence of the crystals orientation was then studied, highlighting thus the following phenomena : the preferential transfers from the disc to the pin; the different kind of indentations under oxygen ; the way the coatings are modified during the sliding : crystals deterioration, Sp3 -> Sp2 transformation. A study concerning the diamond/aluminuim alloys couples was then begun, dealing more particularly with the role of the oxides on the cutting process and the nature of the transfer. A simulation of the diamond coated pin-disc contact was finally realized : this modelling allowed the evaluation of the critical load avoiding the diamond-substrate decohesion, which is particularly important for the coated cutting tools

APA, Harvard, Vancouver, ISO, and other styles

10

Dione, Mamadou. "Recherches expérimentales sur le gommier Acacia sénégal dans le Ferlo sénégalais." Toulouse 3, 1996. http://www.theses.fr/1996TOU30158.

Full text

Abstract:

Ces travaux visent a ameliorer la production en gomme arabique, exsudat d'acacia senegal (l. ) willd. , espece ligneuse d'une grande importance economique et ecologique au sahel. Les recherches, effectuees au nord senegal (station forestiere de m'biddi), s'appuient sur des phases successives d'observation depuis 1984. Le protocole experimental en place de 1989 a 1993 prend en compte 280 arbres repertories dans 7 placeaux situes dans 3 sites dunaires: sommet, replat, depression. Les sujets etudies ont ete plantes entre 1975 et 1978. Les observations montrent l'influence inductrice des saignees. Les types, localisations (milieu de branche) et periodes favorables de ces cares (octobre/novembre) ont ete determines. Les productions se revelent heterogenes selon les sites dunaires (ecarts de 1 a 7, soit 44 a 286 g/arbre selon le site). L'augmentation des rendements apparait liee aussi a la decroissance des stocks hydriques des sols. Des depressions aux sommets dunaires, on assiste, parallelement a une diminution des taux de croissance et de survie des arbres, a une acceleration du rythme de defoliation. Il apparait par ailleurs: 1. Une relation positive entre precocite/degre eleve de defoliation (70-80%) et volume d'exsudation, 2. Une symetrie entre rythmes de la production gommiere et du climat: declenchement en debut de saison seche apres importante chute de l'humidite atmospherique et hausse des temperatures, avec pic d'exsudation marque en decembre (saignees d'octobre/novembre). Les liens eventuels entre degre de vigueur des arbres et exsudation n'ont pu etre clarifies. De meme, la relation entre volume de pluie et exsudation n'est pas confirmee. D'une facon generale l'influence d'un stress hydrique s'avere decisive pour expliquer les modalites de l'induction de gommose parallelement aux rythmes phenologiques. Les nouveaux resultats relatifs a la biologie des gommiers (defoliation, croissance), aux modalites de saignee et d'exsudation (rythmes) en relation avec les parametres climatiques devraient permettre d'optimiser la production gommiere des gommeraies naturelles et artificielles

APA, Harvard, Vancouver, ISO, and other styles

More sources

Books on the topic "Acacia senegal"

1

Osman, Mohamed Elmubarak. Fractionation and characterisation of gum from Acacia senegal. Salford: University of Salford, 1993.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

2

al-Qādir, ʻAbd al-Mājid ʻAbd. al-Ṣamgh al-ʻArabī fī al-Sūdān: Ṣirāʻ bi-lā ḥudūd. Khartoum]: [publisher not identified], 2009.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

3

Elhadi, Faroug Mohamed. Studies on Acacia senegal (L.) Wild. in western Sudan with special reference to variation among populations, host x soil inoculum interaction among populations, and host x Rhizobium strains interactions. 1987.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Acacia senegal"

1

Bährle-Rapp, Marina. "Acacia Senegal." In Springer Lexikon Kosmetik und Körperpflege, 4. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_44.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Khare, C. P. "Acacia senegal Willd." In Indian Medicinal Plants, 1. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-70638-2_15.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Azimova, Shakhnoza S., and Anna I. Glushenkova. "Acacia verek Guill (= Acacia senegal Willd)." In Lipids, Lipophilic Components and Essential Oils from Plant Sources, 557. London: Springer London, 2012. http://dx.doi.org/10.1007/978-0-85729-323-7_1784.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Azimova, Shakhnoza S., and Anna I. Glushenkova. "Acacia senegal (L.) Willd. Senegal gum (Arabic gum tree, gumarabic acacia)." In Lipids, Lipophilic Components and Essential Oils from Plant Sources, 556. London: Springer London, 2012. http://dx.doi.org/10.1007/978-0-85729-323-7_1780.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Bussmann, Rainer W., Narel Y. Paniagua-Zambrana, and Grace N. Njoroge. "Acacia drepanolobium Harmes ex Sjostedt Acacia nilotica (L.) Willd. ex Delile Acacia senegal (L.) Willd. Acacia seyal Delille Acacia tortilis (Forssk.) Hayne Fabaceae." In Ethnobotany of the Mountain Regions of Africa, 1–13. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-319-77086-4_4-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Bussmann, Rainer W., Narel Y. Paniagua-Zambrana, and Grace N. Njoroge. "Acacia drepanolobium Harmes ex Sjostedt Acacia nilotica (L.) Willd. ex Delile Acacia senegal (L.) Willd. Acacia seyal Delille Acacia tortilis (Forssk.) Hayne Fabaceae." In Ethnobotany of the Mountain Regions of Africa, 81–93. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-38386-2_4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

de Pinto, Gladys León. "Promising Gums from Sources other than Acacia senegal." In Cell and Developmental Biology of Arabinogalactan-Proteins, 253–61. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/978-1-4615-4207-0_22.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Williams, P. A., O. H. M. Idris, and G. O. Phillips. "Structural Analysis of Gum from Acacia senegal (Gum Arabic)." In Cell and Developmental Biology of Arabinogalactan-Proteins, 241–51. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/978-1-4615-4207-0_21.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Shahana, Saloni, and Shrish C. Gupta. "Somatic Embryogenesis in a Leguminous Tree — Acacia Senegal (L) Willd." In Somatic Embryogenesis in Woody Plants, 539–52. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-017-3030-3_18.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Palma, Beatriz, and Peter W. Barlow. "Root System Restoration Following Root Pruning of Acacia senegal and its Analysis by Means of an Elementary Petri Net." In Biology of Root Formation and Development, 31–38. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-5403-5_4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!