A Comparison Between Functions of Carbon Nanotube and Reduced Graphene Oxide and Respective Ameliorated Derivatives in Perovskite Solar Cells

Qahtan. A. Yousif,Samira Agbolaghi 한국고분자학회 2020 Macromolecular Research Vol.28 No.5

The reduced graphene oxide (rGO) and carbon nanotube (CNT) components and their derivatives grafted with the irregioregular poly(3-dodecyl thiophene) (rGO-g-PDDT and CNT-g-PDDT) and regioregular poly(3-hexylthiophene) (CNT-g-P3HT and CNT-g-P3HT) polymers were used to improve the morphological, optical, and photovoltaic features of CH3NH3PbI3 perovskite solar cells. The type of carbonic material (CNT or rGO) and regioregularity of grafts affected the cell performances. According to the photoluminescence lifetimes, although the grafted-CNT/ rGO components improved the cell characteristics (15.3-20.5 ns), the corresponding bared nanostructures ruined them (3.0-4.9 ns). In similar conditions, via alteration of rGO to CNT, the average cell performance changed to 14.56 from 14.07% for PDDT-grafted systems and to 16.36 from 15.15% for P3HT-based ones. The self-ordering polymers such as regioregular P3HTs simultaneously induced the crystallinity to the polymeric and non-polymeric constituents. The best photovoltaic data including 22.73 mA/cm2, 75%, 0.96 V and 16.36% with the narrowest distributions were detected in the CH3NH3PbI3 + CNT-g-P3HT solar cells. Perovskite solar cells were perfectly modified with both rGO-g-P3HT and CNT-g-P3HT agents because of the lowest charge-transfer resistance values (93.2 and 90.1Ω), the most intensified crystalline peaks, and the largest absorbances.

Poetry from the perspective of a poem A review of Adonis' poem: "A Tree of Day and Night"

Abdulkareem Nasser Qahtan 한국이슬람학회 2014 한국이슬람학회논총 Vol.24 No.2

The paper contents an introduction which states the justifications of selecting this poem. One of the most prominent justifications is the concern of the poem for its discourse as much as it's concern for itself as an aesthetic text manifested the faculty of the pioneer of modernization in Arabic poetry (Adonis) and his aesthetic experience, though the concern of the poem for its discourse has been noticed in the history of Arabic poetry in different ways of different poets and historical periods. In his analysis of the semantic, syntactic, phonetic and visual aspects of the poem, the researcher shows how the implicit and explicit components work in their differentiation and integration within the framework of the text which is based on narrative, as an event in a concordancing dynamically with time, and also on a poetic image, in a remarkable structure of language mixed of Sufi scholasticism, myth and history. In the Conclusion, the researcher shows that the poem confirms Adonis' understanding of the poetry discourse either in its great importance compared with the human's production of civilization, as poetry -according to him- is the first to exist, and the most comprehensive since its concern with revealing the spiritual truth that guides facts of sciences and philosophies, or in its visionary creativity revealed by means of heart and soul, independently of the will and the power of reason. This poem also confirms its modernist style, as followed by Adonis, with a tendency for modernization and surpassing, shifting language meanings to symbols full of spiritual meanings, using the phonic, calligraphic, syntactic and semantic components of Arabic language, and the human culture including its symbols and myths components, within a vision that combines the subjective with the objective as much as combining the possible with the impossible, the historical with the absolute characteristics. All that produces an artistic structure which does not reveal its potential meanings except by dialogue and interpretation.

Poetry from the perspective of a poem A review of Adonis` poem:"A Tree of Day and Night"

( Abdulkareem Nasser Qahtan ) 한국이슬람학회 2014 한국이슬람학회논총 Vol.24 No.2

The paper contents an introduction which states the justifications of selecting this poem. One of the most prominent justifications is the concern of the poem for its discourse as much as it`s concern for itself as an aesthetic text manifested the faculty of the pioneer of modernization in Arabic poetry (Adonis) and his aesthetic experience, though the concern of the poem for its discourse has been noticed in the history of Arabic poetry in different ways of different poets and historical periods. In his analysis of the semantic, syntactic, phonetic and visual aspects of the poem, the researcher shows how the implicit and explicit components work in their differentiation and integration within the framework of the text which is based on narrative, as an event in a concordancing dynamically with time, and also on a poetic image, in a remarkable structure of language mixed of Sufi scholasticism, myth and history. In the Conclusion, the researcher shows that the poem confirms Adonis` understanding of the poetry discourse either in its great importance compared with the human`s production of civilization, as poetry - according to him- is the first to exist, and the most comprehensive since its concern with revealing the spiritual truth that guides facts of sciences and philosophies, or in its visionary creativity revealed by means of heart and soul, independently of the will and the power of reason. This poem also confirms its modernist style, as followed by Adonis, with a tendency for modernization and surpassing, shifting language meanings to symbols full of spiritual meanings, using the phonic, calligraphic, syntactic and semantic components of Arabic language, and the human culture including its symbols and myths components, within a vision that combines the subjective with the objective as much as combining the possible with the impossible, the historical with the absolute characteristics. All that produces an artistic structure which does not reveal its potential meanings except by dialogue and interpretation.

The Eloquence of Rhythm in Subait`s Poetry: Meter and Rhyme

( Abdulkareem Asa`ad Qahtan ) 한국이슬람학회 2012 한국이슬람학회논총 Vol.22 No.2

This study is about Subait, a Yemen poet, focusing on the concept of rhetoric in his poetry. The rhetoric, here, does not only mean the distinctive style in the process of speech but also it takes into account the social, cultural, psychological and linguistic reality. First, it is the identification of the concept of both meter as a movement system of the syllables of speech and rhyme. The rhyme means in this study the sound which repeats at the end of Satr(half-verse), verse and free verse line. Secondly, it includes analysis of the poems of two divans of Subayt(1918-2006) : al-D umo`al- Dah ikah(The Laughing Tears) and Ma`a al-Fajr (At Dawn) regarding meter, rhymes and quantity. It also has explanation of the findings of the research according to modern criticism, regarding what the Arabic poets have achieved in old and modern poetry. The study analyzes about 116 Standard and colloquial Arabic poems. Further the study discusses the relationship between the meter and semantic syntax structure which are taken from different locations of each verse of the poem. They can be in hashw (inside the whole structure of the verse), the middle of the verse (the end of the first part of the verse) and the end of the verse. Also it analyzes some poems of the two divans. It shows how both rhyme and meter reflect the spread of poetic meaning in the whole structure of the Subayt`s poem. The conclusion shows how Subayt was able to apply meter and rhyme to achieve stylistic effect which is compatible to Modern Arabic poetic romanticism.

시의 주제와 언어 : 샤우끼 샤피끄의 까시다(Hara`iq al-Nabidh)를 중심으로

압둘카림아스아드까흐탄 ( Abdul Kareem Asad Qahtan ) 한국외국어대학교 중동연구소 2010 중동연구 Vol.29 No.1

ةيبرعلا ةغلل تيوصلا ءانبلا في ماغدلإاو في&#

Abd al-Karim Asad Qahtan(ن,ا,ط,ح,ق,د,ع,س,أ, ي,م,ر,ك,ل,ا, د,ب,ع,.د,.أ) 한국아랍어아랍문학회 2017 아랍어와 아랍문학 Vol.21 No.4

Assimilation and Reduplication in the Structure of Arabic Language This paper contains an introduction, which defines both assimilation and reduplication, moreover, it highlights the different opinions of the ancient and contemporary scholars who tackled this phenomenon and their limitations, and then, it highlights the aim of this paper. The aim is to prove that both assimilation and reduplication are two conditions that actually do exist in the structure of Arabic language. When they agree in some of their Syntagmatic conditions, each would have a different nature, function and standard of perception. This paper also contains a preface that explains the relationship between assimilation and reduplication to structure of the Arabic phoneme differentiated mainly by the volume of stress, in addition to highlighting the authenticity of stress and its volume in Arabic language. In the body of this paper, the researcher presents both assimilation and reduplication according to his understanding accompanied by the opinions of both ancient and modern linguists and their limitations. Then, it tackles the function of both assimilation and reduplication in the structure of speech within the requirements of the semantic and linguistic context. This paper arrived at the conclusion that the phonetic and phonological cases tackled by ancient Arab linguists under the category of assimilation, are not actually assimilation, but reduplication to the same sound through its point of articulation with two different methods, in two consecutive points in speech chain, with two different functions, within two different but consecutive syllables and in two different values. It became clear that reduplication is a result of either assimilation, a separate reduplication or according to the origin of its derivational position. In all of these cases, it stipulates that its first syllable must be stressed. Moreover, it has become clear that assimilation leads to reduplication but it is not reduplication itself. When they both stipulate stress, they differ in its concept, function and the standard of perception. Assimilation, as it refers to the linguistic process by which a sound becomes similar to anther adjacent sound, occurs at the process of replacing a certain sound with a similar one adjacent to it in the place of articulation. This takes place before articulation itself as a process, but during articulation, reduplication takes place, which means the repetition of a certain sound in its place of articulation in two different methods and in two consecutive positions in the phonological chain. If we related the sound to its function within the unity of the syllable movement, we would say that: assimilation is the process of overlapping the sound of the most stressed syllable with another sound of a similar place of articulation whether the assimilated sound is present in the first margin of the next syllable in speech or outside speech itself as in dissimilation (Iqlab), while reduplication is the repetition of the sound of the most stressed syllable at the beginning of the margin of the next syllable in speech. Consequently, assimilation can only be recognized mentally, that is… through analogy and comparison while reduplication can be recognized through speaking and listening. The function of assimilation does not exceed facilitating the process of speaking while the function of reduplication varies to include enabling language to add more additional meanings, compensating for assimilation, enabling the root to adapt for the conditions of semantic extension through conjugation and derivation.

الرجز بين القياس والتذوّق قراءة في الموروث العروضيّ والنقديّ

ناطحقدعسأيمركلادبع ( Abdul Kareem Asaad Qahtan ) 한국아랍어아랍문학회 2019 아랍어와 아랍문학 Vol.23 No.1

This research consists of a preface, an introductory chapter, a discussion of the topic along with analysis of its proceedings, evaluation of the results, as well as summary and presentation of the sources and references that the researcher utilized. The preface explores the reasons of conducting this research on Rajaz. In fact, Rajaz, either in its meter or rhyme, has been extensively tackled in many discussions in the ancient and modern monetary heritage. These discussions were concerned with much of its traits such as the reason of naming it like so, its structure, its position with regard to the chronological arrangement of the other measures of Arabic poetry, its relation to both concepts of al-Qareed (poetry) and Qaseed (poem), as well as the aesthetical value of Rajaz poetry compared to the poetry of other meters. These discussions, however, are reviewable in terms of their content and results. That is why this research is valuable and significant. The introductory chapter reviews the concepts, terms and mechanisms to be adopted in this research justifying their usability and validity in achieving the convincing results. Tackling this topic and analyzing its proceedings, the researcher began with discussing the meaning of Rajaz literally and technically, its relation to the meaning of al-Qareed (poetry) and al-Qaseed (poem), as well as discussing the rhythmic structure of Rajaz in the various stages of the Arabic poetry rhetoric improvement. The researcher discussed also the critics’ perceptions about the aesthetical value of Rajaz poetry and evaluated this value in light of the prevailing poetic rhetoric and in its transformations along the historical course. He then ended up with a result that Rajaz is like the first meter in the history of the Arabic-poetic rhythm; the origin from which the other poetic meters in all stages of the Arabic poetry were derived. The notion of al-Qareed (poetry), that was used in a later stage of the improvement of Rajaz, was related to the structure of the two-hemistich line (of poetry), either in Rajaz or other meters that developed thereafter, as it was a measure to the first structure of Rajaz embodied in the two-hemistich line, while the notion of al-Qaseed was related to the form that may represent the notion of the poem. However, the difference of the level of its impact in old and modern times is explained according to its structure compared to the other meters and its relation with the functions of the rhythm in the poetic rhetoric. The functions of the poetic rhythm are determined by warble, tension and expressing the meaning. These are interrelated functions, though each of them has its measurable limitations imposed by the prevailing rhetoric, and it seems to be a dominant function over the other functions. There are two kinds of eloquence that dominated the rhetoric of the Arabic poetry, namely: Oral Eloquence, which prevailed in the old and traditional poetry and Written Eloquence, which prevailed in modern poetry. Between these two kinds, the Romantic Poetry represents a midway or a transition between these two distinctive stages of the development of the Arabic poetic rhetoric. When it comes to Oral Eloquence, the positive value of the poem was to be determined by its ability to achieve quick and immediate aesthetic response by the recipients. That is why Oral Eloquence requires taking care of the sound to the greatest degree; and therefore, the function of musicality dominated. Rajaz poetry is the poorest meter to achieve this function. That is because it is a simple meter that is built on the repetition of a single rhythmic unit that is not composed with another unit(s). This made the highly-cohesive compound meters- on the top of which is al-Taweel meter- clearly dominant. When the dominance was assumed by the Written Eloquence that necessitates the poem to take intensive care of the meaning, as the structure of the line and the hemistiches was overstepped therein to the structure of the foot (of a verse meter). This was made at the expense of taking care of the function of musicality. Thereupon, Rajaz had its considerable impact like the other meters that depend on the repetition of a single or a simple compound unit.

The Arabic Poetic Rhythm from the classic line to the modern: Prosodical study

Abd al-Karim Asad Qahtan 한국아랍어아랍문학회 2018 아랍어와 아랍문학 Vol.22 No.2

The research consists of an introduction that includes a brief definition of poetic rhythm and its forms and defines prosody as a system of syllables in the speech movement. It is also a system that is based on different syllables and their suitability and repetition in the poetic line as well as the qasiad (poem). The research also reviewed the development of prosodic structure within the requirement of the development of the Arab poetic discourse. This development occurred via three forms that each form prevailed a certain stage of the stages of the Arab poetic discourse. The first form is the stiff or static form that was materialized by the single metre and monorhymed qasiad (poem). Then, the diversified form that was materialized by the romantic qasiad (pem) characterized by diversification of poetic line, metre and rhyme. The final one is the dynamic form materialized by the modern qasiad (peom) that is based on the poetic line that does not abide by a certain engineering of phonetic structure, semantic structure or visual structure. The research also reviewed the aesthetic impact of prosody through three functions: the function of tension that is based on the principle of contradiction between phonetic structure and semantic structure. The function of (Music disorder) that is based on the suitability of phonetic structure and its repetition. Finally, the function of expression that is based on diversifying prosodic structure according to the requirements of the semantic structure. The research conclusion confirmed that prosodic structure was not stiff or static but evolved within the development of the Arab poetic discourse.

Phonetic Structure in Arabic “Assimilation and Doubting”

( Abd Al-karim Asad Qahtan ) 한국아랍어아랍문학회 2017 아랍어와 아랍문학 Vol.21 No.4

Assimilation and Reduplication in the Structure of Arabic Language This paper contains an introduction, which defines both assimilation and reduplication, moreover, it highlights the different opinions of the ancient and contemporary scholars who tackled this phenomenon and their limitations, and then, it highlights the aim of this paper. The aim is to prove that both assimilation and reduplication are two conditions that actually do exist in the structure of Arabic language. When they agree in some of their Syntagmatic conditions, each would have a different nature, function and standard of perception. This paper also contains a preface that explains the relationship between assimilation and reduplication to structure of the Arabic phoneme differentiated mainly by the volume of stress, in addition to highlighting the authenticity of stress and its volume in Arabic language. In the body of this paper, the researcher presents both assimilation and reduplication according to his understanding accompanied by the opinions of both ancient and modern linguists and their limitations. Then, it tackles the function of both assimilation and reduplication in the structure of speech within the requirements of the semantic and linguistic context. This paper arrived at the conclusion that the phonetic and phonological cases tackled by ancient Arab linguists under the category of assimilation, are not actually assimilation, but reduplication to the same sound through its point of articulation with two different methods, in two consecutive points in speech chain, with two different functions, within two different but consecutive syllables and in two different values. It became clear that reduplication is a result of either assimilation, a separate reduplication or according to the origin of its derivational position. In all of these cases, it stipulates that its first syllable must be stressed. Moreover, it has become clear that assimilation leads to reduplication but it is not reduplication itself. When they both stipulate stress, they differ in its concept, function and the standard of perception. Assimilation, as it refers to the linguistic process by which a sound becomes similar to anther adjacent sound, occurs at the process of replacing a certain sound with a similar one adjacent to it in the place of articulation. This takes place before articulation itself as a process, but during articulation, reduplication takes place, which means the repetition of a certain sound in its place of articulation in two different methods and in two consecutive positions in the phonological chain. If we related the sound to its function within the unity of the syllable movement, we would say that: assimilation is the process of overlapping the sound of the most stressed syllable with another sound of a similar place of articulation whether the assimilated sound is present in the first margin of the next syllable in speech or outside speech itself as in dissimilation (Iqlab), while reduplication is the repetition of the sound of the most stressed syllable at the beginning of the margin of the next syllable in speech. Consequently, assimilation can only be recognized mentally, that is… through analogy and comparison while reduplication can be recognized through speaking and listening. The function of assimilation does not exceed facilitating the process of speaking while the function of reduplication varies to include enabling language to add more additional meanings, compensating for assimilation, enabling the root to adapt for the conditions of semantic extension through conjugation and derivation.

Flexural performance of cold-formed square CFST beams strengthened with internal stiffeners

Ahmed W. Al-Zand,W.H. Wan Badaruzzaman,Mustafa M. Ali,Qahtan A. Hasan,Marwan S. Al-Shaikhli 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.1

The tube outward local buckling of Concrete-Filled Steel Tube (CFST) beam under high compression stress is still considered a critical problem, especially for steel tubes with a slender section compared to semi-compact and compact sections. In this study, the flexural performance of stiffened slender cold-formed square tube beams filled with normal concrete was investigated. Fourteen (14) simply supported CFST specimens were tested under static bending loads, stiffened with different shapes and numbers of steel stiffeners that were provided at the inner sides of the tubes. Additional finite element (FE) CFST models were developed to further investigate the influence of using internal stiffeners with varied thickness. The results of tests and FE analyses indicated that the onset of local buckling, that occurs at the top half of the stiffened CFST beam’s cross-section at mid-span was substantially restricted to a smaller region. Generally, it was also observed that, due to increased steel area provided by the stiffeners, the bending capacity, flexural stiffness and energy absorption index of the stiffened beams were significantly improved. The average bending capacity and the initial flexural stiffness of the stiffened specimens for the various shapes, single stiffener situations have increased of about 25% and 39%, respectively. These improvements went up to 45% and 60%, for the double stiffeners situations. Moreover, the bending capacity and the flexural stiffness values obtained from the experimental tests and FE analyses validated well with the values computed from equations of the existing standards.