Results of the numerical study on the initial formation stages of low-mass protostellar systems leading to single, binary, triplet, and quadruple protostar systems formation are reported here. In addition to these various types of protostellar objects we also investigate the overall structure formation that takes place within collapsing molecular cores that yield during the course of evolution the spiral structure formation, ring formation, and bar formation under various initial conditions chosen for a rotating solar mass cloud of molecular hydrogen to mimic the states prevailing in star formation regions in our Milky Way galaxy. There have been three key parameters belonging to the initial star forming conditions whose effects on the overall outcome of protostallar systems have been examined. These parameters are the initial thermal state of the prestellar core, the amplitude of azimuthal density perturbation introduced in initially uniform density state of the core, and the impact of the critical density which governs the transition from isothermal to adiabatic thermodynamic behavior of the collapsing core. For protostellar binaries, the separation is determined as a function of the initial thermal state of the core by varying its initial temperature. For this purpose a slightly modified version of the Burkert and Bodenheimer collapse test is taken into consideration. We find that the result is fairly sensitive to both the initial thermal state of the cloud and the initial azimuthal density perturbation’s amplitude A. For A=10 %, variations of only 1 unit Kelvin below 10 K causes a change of up to 100 AU in protobinary separation, while for this small amplitude of perturbation the initial temperatures above 10 K result a single low-mass fragment, instead of a binary, that does not reach even near to the protostellar densities. However, protostellar binaries, do appear if the amplitude of perturbation is enhanced from 10 % to 25 %. A star forming hydrogen gas is normally considered to be initially at 10 K. For structural formation study, we have explored that an oscillation around this normally considered value can be influential in determining the fate of a collapsing gas as it evolves in its structural properties that may lead to formation of proto-stars. We examined the initial range of temperature of star forming gas between 8 K to 12 K and tried to compare the emerging physical properties within the early phase of formation of protostellar system. According to our findings the spiral structures are likely to appear in a strongly perturbed molecular cores that commence their phase of collapse from temperatures lesser than 10 K. However, cores with initial temperatures more than 10 K potentially develop, instead of spiral, a ring structure which afterwards experiences the clumps formation. It is possible to observe a transition from spiral to ring instability at a typical initial core temperature of 10 K. Similarly, while investigating the effects of critical density variations on the evolution of protostellar systems, we find that the critical density affects the structural evolution of the envelope of gas, also the dimension of emerging rotating disk structures during collapse too get affected as well as the number of fragments appearing from the concluding fragmentation of the disks. It is suggested that this mechanism has the potential to give birth to young protostellar objects that may eventually constitute systems of bound multiple protostars. The entire numerical experiment is conducted by using 250025 SPH particles to construct virtually the geometry of each molecular core investigated here.
عبدالقیوم انصاری عبدالقیوم صاحب انصاری بہار کے مشہور نیشنلسٹ اورقومی کارکن تھے۔ انھوں نے قید وبند کے مصائب بھی برداشت کیے اورتحریک پاکستان کے زمانہ میں اپنوں کے ہدف ملامت بھی بنے، لیکن ان کے پائے استقلال میں کوئی لغزش نہیں آئی۔وہ بہار گورنمنٹ میں وزیر تھے لیکن ان کاطورطریق بالکل عوامی تھا۔ ان کی زندگی ارباب حاجت کی مدد کے لیے وقف تھی۔چنانچہ ان کی وفات بھی خدمت کرتے ہی واقع ہوئی۔ سیاسیات میں غایت درجہ انہماک کے باوجود نماز، روزہ کے پابند اوربڑے خلیق اور متواضع تھے۔ [فروری۱۹۷۳ء]
Islamic education curriculum has central value for education process, as education vision direction. Islamic education mission is how to create religious people by leaning perfectly. Curriculum becomes one of success applications and quality in education institution most. Curriculum will develop based on global world and people life style existency. Therefore, education should view people life style increased as learning source that is becomed a value for curriculum step making. Beside that, islamic education curriculum development also becomes teacher’s choice to implement learning manner in class. In where, it’s implementation should be arranged and systematically to make maximal learning either in development vision, indicator, lesson teory, lesson model proccess, learning evaluation or teacher’s development skill. The process of islamic education curriculum development must be done good and awesome also seeing several factors as supports and obstacles of it. In other to get an education result based on such the plan made before(education planning).
This dissertation investigates the syllable structure and stress patterns of Sindhi words through the analysis of behavioral data from speech judgment experiments, and of acoustic data from speech production experiments, conducted with native speakers of Sindhi. There were three basic queries, the first of which was: What is the syllable structure? For this, a syllable judgment study was designed to explore syllable structure in Sindhi indigenous words and English loanwords. Syllable counts and syllabification judgments were elicited from native speakers for words presented in written format. This syllable judgment study sought to determine native speakers’ intuitions about the syllabification of Sindhi words in terms of the major principles: Sonority Sequencing Principle (SSP) and Maximal Onset Principle (MOP) of syllabification, and phonotactic constraints of the language, referencing to consonant clusters syllable-initially, -medially, and -finally. On the basis of the data, the study devised an algorithm for syllabification that illustrates how a Sindhi word is syllabified. Secondly, it investigates the word-level stress patterns in Sindhi and identifies the phonological factors that determine stress location in polysyllabic words. This study also examines the intuition of native speakers by eliciting their judgments about the location of lexical stress in words of two, three, four and five syllables from 150 selected words. The findings from the stress judgment study shows that native speakers have a preference for identifying stress on a heavy syllable. This pattern is strongest in words that have a single heavy syllable. In words with multiple heavy syllables the pattern is less clear. In tri-syllabic words there appears to be a preference for stress on the leftmost heavy syllable, while four-syllable words do not show this pattern as clearly. However, five-syllable words, show a preference for lexical stress on the penultimate syllable, which does not seem to depend on syllable weight. From these data the study concludes that Sindhi is not a fixed stress language. The location of stress varies in words according to the weight of the syllables in the word. This study concludes that Sindhi is a weak quantity-sensitive language and it is not a fixed stress language. Third question investigated here is what are the acoustic correlates of word level stress in Sindhi? This work collects and examines quantitative acoustic data (2000 voice samples of Sindhi speech) from ten native speakers. From the physical examination of stressed and unstressed vocalic sounds, the study found strong evidence that several phonetic properties are altered by word-level stress in Sindhi. The speech materials used in the acoustic analysis are ten minimal stress pairs of words that differ primarily in the location of stress (first vs. second syllable). The test words were all highly familiar words selected and chosen to minimize segmental variation among the words. The acoustic analysis of productions of these 20 words is based on measures of fundamental frequency (F0), vowel formants (F1 and F2) as a measure of vowel quality and vowel duration. In addition, the stop closure duration of the word-initial onset consonant for stressed and unstressed syllables was also measured. The results show strong evidence that stressed syllables have higher F0, F1 and F2, and greater duration values as compared to unstressed syllables. In addition, the study undertook another experiment of preliminary intonational aspects of Sindhi in order to investigate the role of pitch between stress and intonation of contrastive focus accentual phrase in Sindhi, F0 of vowel pitch contours were analyzed for evidence that the location of the beginning of the pitch rise, or the pitch peak varies in relation to the location of the stressed syllable in the word. Sindhi pitch accent rises from the first syllable in disyllable words, irrespective of syllable weight, and the rise is followed by a fall at end of the word. Thus, it was observed, there was a rise and fall in intonation of contrastive focus accentual phrase. A peak occurs on the second or third syllable and may span over two syllables in longer words.