13,749 research outputs found
Taxonomic revision of the genus Amaranthus (Amaranthaceae) in Saudi Arabia
No full textHassan, Walaa A., Al-Shaye, Najla A., Alghamdi, Salma, Korany, Shereen M., Iamonico, Duilio (2022): Taxonomic revision of the genus Amaranthus (Amaranthaceae) in Saudi Arabia. Phytotaxa 576 (2): 135-157, DOI: 10.11646/phytotaxa.576.2.1, URL: http://dx.doi.org/10.11646/phytotaxa.576.2.
Discusiones sobre la teología de al-Bāqillānī en el Magreb: el Tasdīd fī šarḥ al-Tamhīd de ‘Abd al-Ŷalīl b. Abī Bakr al-Dībāŷī al-raba‘ī
No full text[EN] This paper presents a unique manuscript copy of a fifth/eleventh-century Maghribī commentary on al-Bāqillānī’s Kitāb al-Tamhīd. The work, entitled al-Tasdīd fī sharḥ al-Tamhīd, was written by ‘Abd al-Jalīl b. Abī Bakr alDībājī —also known as Ibn al-Ṣābūnī— who had studied the Kitāb al-Tamhīd with al-Bāqillānī’s disciples in Qayrawān. The present study first reviews the transmission of alBāqillānī’s work to the Islamic west. It then continues to present the author of the commentary, to reconstruct the work’s genesis and to describe its content. The final section focuses on a sample chapter and argues that alDībājī follows al-Bāqillānī’s later position on a specific theory —the so-called theory of aḥwāl— of which the Tamhīd strongly disapproved. The Tasdīd is one of the oldest texts of Maghribī Ash‘arism that has come down to us and provides valuable new insights into the school’s early history in the Islamic west[ES] En este artículo presentamos un manuscrito único de un comentario magrebí del Kitāb alTamhīd de al-Bāqillānī datado en elsiglo V/XI. La obra se titula al-Tasdīd fīšarḥ al-Tamhīd escrita por ‘Abd al-Ŷalīl b. Abī Bakr al-Dībāŷī —también conocido como Ibn al-Ṣābūnī—quien estudió el Tamhīd con otros discípulos de al-Bāqillānī en Qayrawān. El presente estudio revisa el proceso de transmisión de la obra de al-Bāqillānī en el Occidente Islámico. Después continúa presentando al autor del comentario, reconstruyendo la génesis del texto y describiendo su contenido. La sección final escoge un capítulo del texto que se ha seleccionado para demostrar cómo al-Dībāŷī sigue la posición tardía de al-Bāqillānī con respecto a la llamada teoría de los aḥwāl- duramente criticada en el Tamhīd. El Tasdīd constituye uno de los textos más antiguos del aš‘arismo magrebí que ha llegado hasta nosotros, ofreciéndonos nuevas y valiosas perspectivas sobre la historia de esta escuela teológica en el Occidente islámicoThe research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no 624808 and the Spanish government’s Ramón y Cajal programme (RYC-2015-18346) awarded to Jan Thiele. Hassan Ansari wishes to thank the Institute for Advanced Study, Princeton for granting him a Long-Term Membership during the preparation of this paper.Peer reviewe
Low pressure adsorption on kaolinite clay minerlas modified by cation exchange at the solid/liquid interface
No full textKaolinite is one of the most abundant aluminosilicate minerals, occurring primarily as clay-sized particles with high surface area-to-volume ratios. The surface of kaolinite particles can be considered as heterogeneous as crystallites present at least two different types of faces, basal and edge faces, with different surface chemistry and exchange proprieties. It is commonly believed that exchangeable cations of kaolinites are mainly located on the edge faces. However, the basal surfaces can also carry a constant charge due to isomorphous substitution of Si4+ by Al3+ in tetrahedra and Al3+ by Mg2+ in octahedra. This aim of this work is to study the influence of the nature of surface cations on the surface properties of kaolinite at the solid/gas interface. Argon low pressure gas adsorption coupled to the Derivative Isotherms Summation method [1-3], used for long time to derive geometrical properties of kaolinites powder was applied on monovalent kaolinite samples (Li+, Na+, K+, Cs+) [4-6]. By comparing the adsorption isotherms it appears that the nature of surface cation influences the adsorption phenomena on edge and basal faces. On edge faces, the exchanged cations generate nanorugosity and take part to the first argon monolayer. On basal faces, two families of cations are presents in small quantity: for the first family, argon adsorption energy is slightly sensitive to the nature of the cation; for the second one, argon adsorption energy depends on the nature of surface cation [4]. The influence of outgassing temperature (110°C-350°C) on surface properties of kaolinite shows that, for the first family, surface cations are strongly linked to surface and probably correspond to the compensation of local charge defects generated by tetrahedral or octahedral substitutions. For the second one, surface cations were physisorbed on the surface and correspond to neutral compounds [5]. On the quantitative point of view, it was shown that the estimation of the aspect ratio of kaolinite should be carried out with monovalent cations of small size (Li+, Na+) with surface outgassing at 200°C [4-6]. [1] F. Villiéras et al., Langmuir, 8 (1992) 1789. [3] J.M. Cases et al., C.R. Acad. Sci., Paris, 331 (2000) 763. [2] F. Villiéras et al., C.R. Géoscience, 334 (2002) 597. [4] M. Sayed Hassan et al., Langmuir, 21 (2005) 12283. [5] M. Sayed Hassan et al., J. Colloid Interface Science, 296 (2006) 614. [6] M. Sayed Hassan et al., Langmuir, Submitte
Low pressure adsorption on kaolinite clay minerlas modified by cation exchange at the solid/liquid interface
No full textKaolinite is one of the most abundant aluminosilicate minerals, occurring primarily as clay-sized particles with high surface area-to-volume ratios. The surface of kaolinite particles can be considered as heterogeneous as crystallites present at least two different types of faces, basal and edge faces, with different surface chemistry and exchange proprieties. It is commonly believed that exchangeable cations of kaolinites are mainly located on the edge faces. However, the basal surfaces can also carry a constant charge due to isomorphous substitution of Si4+ by Al3+ in tetrahedra and Al3+ by Mg2+ in octahedra. This aim of this work is to study the influence of the nature of surface cations on the surface properties of kaolinite at the solid/gas interface. Argon low pressure gas adsorption coupled to the Derivative Isotherms Summation method [1-3], used for long time to derive geometrical properties of kaolinites powder was applied on monovalent kaolinite samples (Li+, Na+, K+, Cs+) [4-6]. By comparing the adsorption isotherms it appears that the nature of surface cation influences the adsorption phenomena on edge and basal faces. On edge faces, the exchanged cations generate nanorugosity and take part to the first argon monolayer. On basal faces, two families of cations are presents in small quantity: for the first family, argon adsorption energy is slightly sensitive to the nature of the cation; for the second one, argon adsorption energy depends on the nature of surface cation [4]. The influence of outgassing temperature (110°C-350°C) on surface properties of kaolinite shows that, for the first family, surface cations are strongly linked to surface and probably correspond to the compensation of local charge defects generated by tetrahedral or octahedral substitutions. For the second one, surface cations were physisorbed on the surface and correspond to neutral compounds [5]. On the quantitative point of view, it was shown that the estimation of the aspect ratio of kaolinite should be carried out with monovalent cations of small size (Li+, Na+) with surface outgassing at 200°C [4-6]. [1] F. Villiéras et al., Langmuir, 8 (1992) 1789. [3] J.M. Cases et al., C.R. Acad. Sci., Paris, 331 (2000) 763. [2] F. Villiéras et al., C.R. Géoscience, 334 (2002) 597. [4] M. Sayed Hassan et al., Langmuir, 21 (2005) 12283. [5] M. Sayed Hassan et al., J. Colloid Interface Science, 296 (2006) 614. [6] M. Sayed Hassan et al., Langmuir, Submitte
Low pressure adsorption on kaolinite clay minerlas modified by cation exchange at the solid/liquid interface
No full textKaolinite is one of the most abundant aluminosilicate minerals, occurring primarily as clay-sized particles with high surface area-to-volume ratios. The surface of kaolinite particles can be considered as heterogeneous as crystallites present at least two different types of faces, basal and edge faces, with different surface chemistry and exchange proprieties. It is commonly believed that exchangeable cations of kaolinites are mainly located on the edge faces. However, the basal surfaces can also carry a constant charge due to isomorphous substitution of Si4+ by Al3+ in tetrahedra and Al3+ by Mg2+ in octahedra. This aim of this work is to study the influence of the nature of surface cations on the surface properties of kaolinite at the solid/gas interface. Argon low pressure gas adsorption coupled to the Derivative Isotherms Summation method [1-3], used for long time to derive geometrical properties of kaolinites powder was applied on monovalent kaolinite samples (Li+, Na+, K+, Cs+) [4-6]. By comparing the adsorption isotherms it appears that the nature of surface cation influences the adsorption phenomena on edge and basal faces. On edge faces, the exchanged cations generate nanorugosity and take part to the first argon monolayer. On basal faces, two families of cations are presents in small quantity: for the first family, argon adsorption energy is slightly sensitive to the nature of the cation; for the second one, argon adsorption energy depends on the nature of surface cation [4]. The influence of outgassing temperature (110°C-350°C) on surface properties of kaolinite shows that, for the first family, surface cations are strongly linked to surface and probably correspond to the compensation of local charge defects generated by tetrahedral or octahedral substitutions. For the second one, surface cations were physisorbed on the surface and correspond to neutral compounds [5]. On the quantitative point of view, it was shown that the estimation of the aspect ratio of kaolinite should be carried out with monovalent cations of small size (Li+, Na+) with surface outgassing at 200°C [4-6]. [1] F. Villiéras et al., Langmuir, 8 (1992) 1789. [3] J.M. Cases et al., C.R. Acad. Sci., Paris, 331 (2000) 763. [2] F. Villiéras et al., C.R. Géoscience, 334 (2002) 597. [4] M. Sayed Hassan et al., Langmuir, 21 (2005) 12283. [5] M. Sayed Hassan et al., J. Colloid Interface Science, 296 (2006) 614. [6] M. Sayed Hassan et al., Langmuir, Submitte
Transport and deposition of nanoparticles in microvascular networks
No full textTargeted delivery of therapeutic drugs to specific sites in the body is becoming a norm for treating many diseases, such as cancer. Engineered nanoparticles have emerged as the most suitable carriers for this purpose. Often times, these particles are directly injected into the bloodstream and carried by the circulation to the targeted sites. The efficiency of the nanoparticle delivery depends on how many of them eventually reach the target sites before being removed by kidney filtration or by phagocytosis. Two hydrodynamic processes that are critical in the efficient delivery are margination of these particles from the core of a blood vessel towards the vessel wall, and adhesion of the particles on to the endothelial cell surface lining the vessel wall. Previous studies have considered margination and adhesion of nanoparticles in simple geometry, such as parallel plate flow chambers, and bifurcating channels. These studies have shown that the particle size and shape significantly affect their margination. However, blood vessels in the microcirculation form complex networks known as microvascular networks that are characterized by highly tortuous vessels, and frequent and hierarchical bifurcations and mergers. A detailed quantitative analysis of particle margination and adhesion under such complex geometry is missing. Towards that end, in this thesis we utilize a high-fidelity computational model of cellular-scale blood flow in physiologically-realistic microvascular networks to study the margination and adhesion of nano- and micro-particles. The objective is to understand the simultaneous effects of the flowing red blood cells and the complex geometry of the vasculatures on the margination and adhesion of particles. In the first part of the work, we model nanoparticles as volume-less point particles that are simply advected by the streamlines. We find that margination and adhesion are highly non-uniform across the networks. Specifically, we find that adhesion is significantly high in the bifurcation regions, while margination is high in the venular segments. In the second part of this work, we modeled particles as rigid finite-size spheres. Similar heterogeneity is observed herein, and the margination area density is also correlated to the CFL thickness. Arterioles and venules have high levels of margination and adhesion likelihood, while capillaries have the lowest. Our simulations show that irrespective of hematocrit levels and network topology, the accumulation of the marginated particles and the likelihood of adhesion increase with increasing particle size. In the last part of this work, we study shape effect of particles by considering oblate and prolate shapes. Similar heterogeneity is observed, and the margination area density is also correlated to the CFL thickness. Irrespective of hematocrit levels and network topology, margination of ellipsoidal particles was observed to be higher, with the oblate particles showing the maximum margination compared to other shapes. Our work underscores the importance of network topology on the distribution of the therapeutic drug within the targeted tissue.Ph.D.Includes bibliographical referencesby Hassan M. Al-Sira
Nikolaos Metaxas - Hesham M. Hassan, “Khandax / al-Khandaq: A New Approach to The Toponym”, Κρητικά Χρονικά 42 (2022), Pp. 167-201.
No full textThe purpose of this paper is to present certain facts concerning the history, etymology and symbolic role attached to the toponym Rabaḍ al-Khandaq -ربض الخندق short form: al-Khandaq- الخندق - Χάνδαξ, marking an endeavour that will result in a thoroughly new interpretation of the Byzantine and Arabic sources, in an attempt for a deeper comprehension of the historical identity of the Emirate of Crete. This paper assumes that the study of toponyms and their respective etymology can play a decisive role (not as an exclusive source of completely new information, but as an aiding element) in constructing a complete overview of Cretan history during the period of the Arab-Andalusian dominion (824-961 CE). Thus, after examining the etymology, history and course of the word "khandaq" through the ages, we will present its religious symbolism and, as a working assumption, its potential influence on the naming of the Emirate of Crete’s capital. Afterwards, we will examine the word rabaḍ and, while demonstrating the erroneous until today translation of the toponym "Rabaḍ al-Khandaq", we will pass –in light of the information of the sources and the secondary bibliography– to a new interpretation, which we deem able to provide new information on the ideological and religious identity of the Emirate of Crete. Finally, based on this new approach, we will examine a potential link between the Arabic name of the Cretan Khandax –Rabaḍ al-Khandaq– and the revolt of the suburb of Shaqunda “Rabaḍ Shakunda” in Cordoba, which took place in 818 CE.Key words: Khandax, Crete, Rabaḍ al-Khandaq, Rabaḍ Shakund
Impact of Poultry Manure-Derived Biochar and Bio-Fertilizer Application to Boost Production of Black Cumin Plants (Nigella sativa L.) Grown on Sandy Loam Soil
No full textBiochar derived from poultry manure increases nutrient availability and promotes plant growth. This study investigated the effect of biochar with mycorrhizal and/or plant growthpromoting rhizobacteria on soil fertility, chemical properties, oil, and seed yield of Black Cumin (Nigella sativa L.) plants. A split-plot design with three replicates was employed, with biochar derived from poultry litter (BC) applied at rates of 0, 5, and 10 t ha−1, with beneficial microbes such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) affecting the growth of Black Cumin plants, and some soil properties, such as pH, electrical conductivity (EC), soil organic matter (SOM) and fertility index (FI), showing significant differences (p ≤ 0.05) among biochar and/or bio-fertilizer treatments. All biochar treatments with or without bio-fertilizers significantly increased pH, EC, OM and FI in comparison to the control treatment. The results demonstrated that applying biochar at the highest rate (10 t ha−1) increased fresh and dry capsule weights by 94.51% and 63.34%, respectively, compared to the control treatment (C). These values were significantly increased by 53.05 and 18.37%, compared to untreated plants when combined with AMF and PGPR. Furthermore, when biochar was applied in conjunction with both AMF and PGPR, fresh and dry capsule weights saw significant increases of 208.84% and 91.18%, respectively, compared to the untreated control treatment. The interaction between biochar, AMF, and PGPR
significantly improved plant growth, yield, soil properties, and the fixed and volatile oil content of Black Cumin. These findings suggest that the combined application of biochar, AMF, and PGPR enhances nutrient availability and uptake, leading to improved growth and higher yields in Black Cumin plants, resulting in increased yield productio
sj-pdf-1-vet-10.1177_03009858221082300 – Supplemental material for Neuropathology of feral conures with bromethalin toxicosis
No full textSupplemental material, sj-pdf-1-vet-10.1177_03009858221082300 for Neuropathology of feral conures with bromethalin toxicosis by Mauricio Seguel, Rita McManamon, Drury Reavill, Fern Van Sant, Sayed M. Hassan, Branson W. Ritchie and Elizabeth W. Howerth in Veterinary Pathology</p
Conservation in an Islamic context a case study of Makkah
No full textThe Holy Qu’ rān contains many injunctions for Muslims to respect and conserve the natural environment but few address the built environment. Habitat at the time of the Prophet (PBOH) was in the vernacular and relatively impermanent. The first habitat was the cave, the second the tent and then simple flat roofed buildings of post and lintel construction made of mud and rubble. Later buildings were not indigenous but reflected the architectural styles and techniques of Muslim pilgrims from beyond the Arabian Peninsula. Permanent exotic buildings were later erected as reminders of holy places and events. This work advances a case to restore and preserve historic and religious sites in Makkah, Saudi Arabia. Makkah is the destination for millions of Muslim pilgrims who annually pay homage to Allah during the occasions of Hajj, Ramadan and Umra. The tranquillity and peaceful ambience that one associates with the holiest of Islamic experiences have, over the years, given way to jostling crowds of people who must be expediently housed, fed, transported, and protected. Due to the lack of planning and the insensitive but profitable development of the city, Makkah is in grave danger of becoming a bustling metropolis instead of a sanctuary where pilgrims gather to perform their religious rites and reaffirm their dedication to Allah. The author calls for professional planning and international cooperation to guide future development for this expanding and sensitive area. The author's ideas are grounded in practical and aesthetic study, therefore, the political, environmental and economic issues are examined in relationship to religious, historic and artistic values. The author makes proposals for a future Makkah that would provide pilgrims with the physical comforts, security, and serene environment they deserve—without destroying the city they came to visit. The author discusses preservation and conservation in the western world and the need for their acceptance in Muslim countries, the former being an aesthetic and intellectual concept sustained by law and the latter being the prescribed free expression of the individual unhindered by material considerations. Both worlds are rapidly being overwhelmed by materialism, but body, mind and spirit combine in making us aware of our surroundings and the way in what we see around us has come into being
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