10,782 research outputs found
Effects of sulfonation process on thermal behavior and microstructure of sulfonated polysulfone membranes as a material for Proton Exchange Membrane (PEM)
This paper reports the effect of sulfonation processon thermal behavior and microstrucutre of sulfonated polysulfone membrane. Various degree of sulfonation reactin has been conducted and the sulfonated membranes were characterized by thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), x-ray diffraction (XRD) and scanning electron microscopy (SEM). Modifications of the origin polysulfone polymer resulted in an increment value of glass transition temperature (Tg) due to the introduction of sulfonic acid group to the polymer backbone. However, due to some hindrance such as trace amount of organic solvent left during solvent evaporation and high hydrophilicity of the produced sulfonated membranes resulted in decreasing values of Tg. The polymer membrane showed lower degradation temperature as a function of degree of sulfonation. From XRD analysis, it was found that the membrane shows slight crystalline behavior after the sulfonation reaction. Detail discussions and observation of the alteration in microstructure of the sulfonated membrane were supported by SEM micrograph
Effect of non-solvent additives on the structure and performance of PVDF hollow fiber membrane contactor for CO2 stripping
Microporous polyvinylidene fluoride (PVDF) hollow fiber membranes with various non-solvent additives, i.e. lithium chloride, glycerol, polyethylene glycol (PEG-400), methanol and phosphoric acid, were fabricated for CO2 stripping via membrane contactors. The membranes were characterized in terms of liquid entry pressure, contact angle, gas permeation and morphology analysis. CO2 stripping performance was investigated by using an in-house made stainless steel module with CO2-preloaded aqueous diethanolamine as the liquid absorbent. Hydrophobicity and gas permeability of the membranes reduced with the addition of a non-solvent additive in the polymer dope but increase in liquid entry pressure was observed as more sponge-like structures developed in the inner layer of the fibers. It was found that PVDF/PEG-400 membrane produced the highest stripping flux of 4.03×10-2 mol m-2 s-1 which can be correlated to its high gas permeation and high effective surface porosity. The result of long-term stripping operation indicated an approximatly 80% stripping flux reduction which can be related to the interaction of polymer membrane and amine solution at high temperature
إنتاج مادة 17 ألفا هيدروكسي البروجستيرون على مستوى المخمر المعملي بواسطة فطرة كاننجهاميلا إيكينولاتا
The mircrobiological transformation of progesterone by a local isolate of Cunninghamella echiiiulata using a laboratory fermentor was studied. Progresterone (10-50 g/1) wetted by Tween 80 was added to 48-hour old culture and the transformation was left to proceed for 72 hours. Thereafter, the different transformation products were resolved chromatog-raphically. The identity of each product was established through the determination of m.p., mixed m.p., optical rotation and ultraviolet as well as infrared absorption spectra. A comparison of the R{ values of each product with that of the corresponding reference using different solvent systems as well as their colour expressed with two spray reagents, was used as a further proof for the identity of the isolated products. With all concentrations of progesterone tested, maximum yield of 17ot -hydroxyprogesterone was obtained after 48 hours of fermentation Progesterone concentrations of 10 and 20 g/1 were almost quantitatively converted to the different transformation products after 72 hours of fermentation. Using a concentration of 20 g/1 and incubation period of 48 hours, the transformation product mixture consisted of unchanged progesterone (6%), 17 o< -hydroxyprogesterone (54%),llotrhydroxyprogesterone (29%) and llo<;,17<^-dihydroxy-progesterone (2.5%).تم استخدام مخمر صناعي سعة 2 لتر لاختيار مقدرة الفطرة على تكوين هذه المادة في ظروف تشبه تلك المطبقة في الصناعة . وبدراسة تركيزات متعددة فن مادة البروجستيرون تتراوح ما بين 10جرام /لتر إلى 50جرام /لتر ، وجد أن أنسب التركيزات المختبرة هو تركيز 20 جرام من البروجستيرون لكل لترمن الوسط الغذائي ، حيث تم تحويل كل البووجستيرون المضاف إلى المشتقات المختلفة خلال 72 ساعة من بدء الاضافة . ووجد أن أعلى معدل لتكوين مادة 17 ألفا - هيدروكسي البروجستيرون كان بعد 48 ساعة من بدأ إضافة البروجستيرون .
عند فصل المواد الناتجة من تحول البروجستيرون بواسطة الفطرة المستخدمة وذلك بواسطة أعمدة الفصل باستخدام مادة الالومينا وجد أن البروجستيرون يتحول إلى :
17 ألفا - هيدروكسي البروجستيرون ( 54 %)
11 ألفا - هيدروكسي البروجستيرون (29%)
11 ألفا ، 17 ألفا - ثنائي هيدروكسي البروجستيرون (2.5%
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The detection and classification of blast cell in Leukaemia Acute Promyelocytic Leukaemia (AML M3) blood using simulated annealing and neural networks
This paper was delivered at AIME 2011: 13th Conference on Artifical Intelligence in Medicine.This paper presents a method for the detection and classification of blast cells in M3 with others sub-types using simulated annealing and neural networks. In this paper, we increased our test result from 10 images to 20 images. We performed Hill Climbing, Simulated Annealing and Genetic Algorithms for detecting the blast cells. As a result, simulated annealing is the “best” heuristic search for detecting the leukaemia cells. From the detection, we performed features extraction on the blast cells and we classifying based on M3 and other sub-types using neural networks. We received convincing result which has targeting around 97% in classifying of M3 with other sub-types. Our results are based on real world image data from a Haematology Department.Universiti Sains Islam Malaysia and the Ministry of Higher Education, Malaysi
0+ states in the large boson number limit of the Interacting Boson Approximation model
Studies of the Interacting Boson Approximation (IBA) model for large boson
numbers have been triggered by the discovery of shape/phase transitions between
different limiting symmetries of the model. These transitions become sharper in
the large boson number limit, revealing previously unnoticed regularities,
which also survive to a large extent for finite boson numbers, corresponding to
valence nucleon pairs in collective nuclei. It is shown that energies of 0_n^+
states grow linearly with their ordinal number n in all three limiting
symmetries of IBA [U(5), SU(3), and O(6)]. Furthermore, it is proved that the
narrow transition region separating the symmetry triangle of the IBA into a
spherical and a deformed region is described quite well by the degeneracies
E(0_2^+)=E(6_1^+), E(0_3^+)=E(10_1^+), E(0_4^+)=E(14_1^+), while the energy
ratio E(6_1^+) /E(0_2^+) turns out to be a simple, empirical, easy-to-measure
effective order parameter, distinguishing between first- and second-order
transitions. The energies of 0_n^+ states near the point of the first order
shape/phase transition between U(5) and SU(3) are shown to grow as n(n+3), in
agreement with the rule dictated by the relevant critical point symmetries
resulting in the framework of special solutions of the Bohr Hamiltonian. The
underlying partial dynamical symmetries and quasi-dynamical symmetries are also
discussed.Comment: 6 pages, 4 postscript figures, LaTeX. To appear in the Proceedings of
the International Conference on Nuclear Physics and Astrophysics: From Stable
Beams to Exotic Nuclei (Cappadocia, 2008
Properties of dense strange hadronic matter with quark degrees of freedom
The properties of strange hadronic matter are studied in the context of the modified quark-meson coupling model using two substantially di erent sets of hyperon-hyperon (Y Y ) interactions. The first set is based on the Nijmegen hard core potential model D with slightly attractive Y Y interactions. The second potential set is based on the recent SU(3) extension of the Nijmegen soft-core potential NSC97 with strongly attractive Y Y interactions which may allow for deeply bound hypernuclear matter. The results show that, for the first potential set, the hyperon does not appear at all in the bulk at any baryon density and for all strangeness fractions. The binding energy curves of the resulting N system vary smoothly with density and the system is stable (or metastable if we include the weak force). However, the situation is drastically changed when using the second set where the hyperons appear in the system at large baryon densities above a critical strangeness fraction. We find strange hadronic matter undergoes a first order phase transition from a N system to a N for strangeness fractions fS > 1.2 and baryonic densities exceeding twice ordinary nuclear matter density. Furthermore, it is found that the system built of N is deeply bound. This phase transition a ects significantly the equation of state which becomes much softer and a substantial drop in energy density and pressure are detected as the phase transition takes place. PACS:21.65.+f, 24.85.+p, 12.39B
Pengaruh Penerapan Model Pembelajaran Contekstual Teaching And Learning terhadap Pemahaman Konsep Matematika Peserta Didik Kelas VIII SMP Negeri 16 Mandai
Penelitian ini merupakan penelitian eksperimen yang bertujuan untuk mengetahui ada tidaknya pengaruh penerapan model pembelajaran Contekstual Teaching and Learning terhadap pemahaman konsep matematika peserta didik kelas VIII SMP Negeri 16 Mandai. Jenis penelitian ini adalah penelitian kuantitatif dengan desain Nonequivalent Control Group Designed. Teknik pengambilan sampel dilakukan dengan cara acak (Random Sampling) kelas yang terpilih adalah kelas VIII. A dan Kelas VIII. B, dengan jumlah 54 orang yang terdiri dari 27 orang untuk Kelas VIII. A yaitu sebagai kelas eksperimen (menggunakan model pembelajaran Contekstual Teaching and Learning) dan 27 Orang untuk kelas VIII. B yaitu sebagai kelas Kontrol (menggunakan model pembelajaran konvensional). Data dianalisis menggunakan program SPSS dengan menggunakan uji t independen untuk melihat pengaruh penerapan model pembelajaran Contekstual Teaching and Learning terhadap pemahaman konsep matematika peserta didik kelas VIII SMP Negeri 16 Mandai pada materi peluang.Hasil penelitian menunjukkan bahwa rata-rata nilai pemehaman konsep matematika peserta didik pada kelompok eksperimen lebih tinggi dibandingkan dengan kelompok kontrol ditandai dengan p=0,00(1/2p< 0,025) dan besar pengaruh yang ditimbulkan setelah penerapan model Contekstual Teaching and Learning sebesar 91,9 %. Hal ini membuktikan bahwa penerapan model pembelajaran Contekstual Teaching and Learning sangat berpengaruh terhadap pemahaman konsep matematika peserta didik Kelas VIII SMP Negeri 16 Mandai pada materi peluang
Hot hypernuclear matter in the modified quark meson coupling model
Hot hypernuclear matter is investigated in an explicit SU(3) quark model based on a mean field description of nonoverlapping baryon bags bound by the self-consistent exchange of scalar sigma, zeta and vector omega,phi mesons. The sigma, omega mean fields are assumed to couple to the u, d-quarks while the zeta ,phi mean fields are coupled to the s-quark. The coupling constants of the mean fields with the quarks are assumed to satisfy SU(6) symmetry. The calculations take into account the medium dependence of the bag parameter on the scalar fields sigma, zeta. We consider only the octet baryons N,Lambda,Sigma, Xi in hypernuclear matter. An ideal gas of the strange mesons K and K is introduced to keep zero net strangeness density. Our results for symmetric hypernuclear matter show that a phase transition takes place at a critical temperature around 180 MeV in which the scalar mean fields sigma, zeta take nonzero values at zero baryon density. Furthermore, the bag contants of the baryons decrease significantly at and above this critical temperature indicating the onset of quark deconfinement. The present results imply that the onset of quark deconfinement in SU(3) hypernuclear matter is much stronger than in SU(2) nuclear matter. PACS:21.65.+f, 24.85.+p, 12.39B
Analisis USAha Alat Tangkap Cantrang (Boat Seine) Di Pelabuhan Perikanan Pantai Tawang Kabupaten Kendal
Information of fishermen income level are very needed to reach the welfare population especially fishermen. Fisheries effort that will be run by businessman has to produce a suistainable profit. Therefore, it needs to be evaluated by effort analysis. The purpose of this study was to analyze the feasibility of Denish seine's fishermen in Tawang's coastal fishing port, Kendal region. This research was conducted on Mei 2012 in Tawang's coastal fishing port. The methodology that used in this research is descriptive method by observation survey. It was conducted to obtain the facts, both about the social, economic, political of population or region. The determination of the samples for this research based on Arikunto (2002) is equal 42 samples.This effort analyse used discounted criterion method. From this method, we got NPV Ratio valueable mean Rp13.504.227,58 (NPV is positive), B/C Ratio valueable mean 1,02 (B/C > 1) and IRR valueable mean 23,74 %, it means Denish seine's effort in Tawang's coastal fishing port is feasible to continue
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