Evaluation Grid for xMOOCs

Massive Open Online Courses, shortly MOOCs, are a phenomenon nowadays. The number of courses is worldwide steadily increasing since Sebastian Thrun has offered a free online course for more than 100.000 students. Nowadays, decision makers and students as well as lecturers are asking about the quality of such courses. After a live experiment on 15 randomly chosen courses and a brief literature review, we discuss the possibility of finding an evaluation grid for xMOOCs. The finally suggested criteria can be used now for future investigations

Reduced graphene oxide-multiwalled carbon nanotubes hybrid film with low Pt loading as counter electrode for improved photovoltaic performance of dye-sensitised solar cells

In this work, the role of reduced graphene oxide (rGO) with hyperbranched surfactant and its hybridisation with multiwalled carbon nanotubes (MWCNTs) and platinum (Pt) nanoparticles (NPs) as counter electrode (CE) were investigated to determine the photovoltaic performance of dye-sensitised solar cells (DSSCs). Sodium 1,4-is(neopentyloxy)-3-(neopentyloxycarbonyl)- 1,4-dioxobutane-2-sulphonate (TC14) surfactant was utilised as dispersing and stabilising agent in electrochemical exfoliation to synthesise graphene oxide (GO) as initial solution for rGO production prior to its further hybridisation and fabrication as thin film. A chemical reduction process utilising hydrazine hydrate was conducted to produce rGO due to the low temperature process and water-based GO solution. Subsequently, hybrid solution was prepared by mixing 1 wt% MWCNTs into the produced rGO solution. TC14-rGO and TC14-rGO_MWCNTs hybrid solution were transferred into fluorine-doped tin oxide substrate to fabricate thin film by spraying deposition method. Finally, the CE films were prepared by coating with thin Pt NPs. Photoanode film was prepared by a two-step process: hydrothermal growth method to synthesise titanium dioxide nanowires (TiO2 NWs) and subsequent squeegee method to apply TiO2 NPs. According to solar simulator measurement, the highest energy conversion efficiency (η) was achieved by using CE-based TC14-rGO_MWCNTs/Pt (1.553%), with the highest short current density of 4.424 mA/cm2. The highest η was due to the high conductivity of CE hybrid film and the morphology of fabricated TiO2 NWs/TiO2 NPs. Consequently, the dye adsorption was high, and the photovoltaic performance of DSSCs was increased. This result also showed that rGO and rGO_MWCNTs hybrid can be used as considerable potential candidate materials to replace Pt gradually

Extracting Arabic composite names using genitive principles of Arabic grammar

Named Entity Recognition (NER) is a basic prerequisite of using Natural Language Processing (NLP) for information retrieval. Arabic NER is especially challenging as the language is morphologically rich and has short vowels with no capitalisation convention. This article presents a novel rule-based approach that uses linguistic grammar-based techniques to extract Arabic composite names from Arabic text. Our approach uniquely exploits the genitive Arabic grammar rules; in particular, the rules regarding the identification of definite nouns (معرفة) and indefinite nouns (نكرة) to support the process of extracting composite names. Based on domain knowledge and Arabic Genitive Rules (AGR), the developed approach formalises a set of syntactical rules and linguistic patterns that initially use genitive patterns to classify definiteness within phrases and then extracts proper composite names from the unstructured text. The developed novel approach does not place any constraints on the length of the Arabic composite name and our initial experimentation demonstrated high recall and precision results when the NER algorithm was applied to a financial domain corpus

Kinetička Bunemanova nestabilnost u prašnjavoj plazmi u različitim temperaturnim uvjetima

Recent theoretical work on the excitation of Buneman\u27s instability in inhomogeneous anisotropic dusty plasmas is presented. Plasmas with different temperature regime are considered. The dispersion relation is derived and solved for a 1-D Buneman instability excited in such plasmas. Electron to ion temperature ratio, degree of plasma inhomogeneity and dust grains thermal velocity are found to play a crucial role in the growth and damping of Buneman instability.Predstavljamo nedavna teorijska istraživanja uzbude Bunemanove nestabilnosti u nehomogenim anizotropnim prašnjavim plazmama. Razmatramo plazme u različitim temperaturnim uvjetima. Izvodimo disperzijsku relaciju i rješavamo 1D Bunemanovu nestabilnost uzbuđenu u takvim plazmama. Nalazimo da su omjer temperature elektrona i iona, stupanj nejednolikosti plazme i toplinska brzina zrnaca prašine ključni za rast i gušenje Bunemanove nestabilnosti

Comparison of Ising magnet on directed versus undirected Erdos-Renyi and scale-free network

Scale-free networks are a recently developed approach to model the interactions found in complex natural and man-made systems. Such networks exhibit a power-law distribution of node link (degree) frequencies n(k) in which a small number of highly connected nodes predominate over a much greater number of sparsely connected ones. In contrast, in an Erdos-Renyi network each of N sites is connected to every site with a low probability p (of the orde r of 1/N). Then the number k of neighbors will fluctuate according to a Poisson distribution. One can instead assume that each site selects exactly k neighbors among the other sites. Here we compare in both cases the usual network with the directed network, when site A selects site B as a neighbor, and then B influences A but A does not influence B. As we change from undirected to directed scale-free networks, the spontaneous magnetization vanishes after an equilibration time following an Arrhenius law, while the directed ER networks have a positive Curie temperature.Comment: 10 pages including all figures, for Int. J, Mod. Phys. C 1

Kinetics and Mechanism of Reduction of 4(p-Dimethylamino)-Benzylidene-3-Methyl-1-Phenyl-2-Pyrazolin-5-one by Bisulphite Ions in Aqueous Ethanolic Media

The kinetics of the title reduction studied in aqueous ethanolic media spectrophotometrically. The effect of hydrogen ion concentration on the reduction rate was investigated in buffer solutions at constant ionic strength of 1.0. The reaction was found to be of the first order in both reactants and inverse first order with respect to the hydrogen ion. The rate of the reaction decreased with increasing ethanol as well as hydrogen ion concentrations. Pseudo-first-order rate constant, kob was obtained by monitoring the disappearance of the [dye]. Activation parameters have been evaluated and a tentative reaction mechanism was discussed

Utility of the Guy’s Stone Score in predicting different aspects of percutaneous nephrolithotomy

Objective: To evaluate Guy’s scoring system (GSS) as a grading system for complexity of kidney stone before percutaneous nephrolithotomy (PCNL) as a predictor for different items of outcome.Patients and methods: Between July 2014 till July 2015, 100 patients with renal stone (s) and candidates for prone PCNL were evaluated and graded by GSS preoperatively. All intraoperative and postoperative data and complications using modified Clavien system were recorded, collected and statistically analyzed in relation to different grades of GSS to evaluate its predictive ability to different items of outcome.Results: Mean age of the patients was 47.38 ± 14.6 years. The patients were distributed in different grades of GSS with no statistically significant difference as mean age, sex, and mean BMI of the patients, stone side and previous renal surgery. There was high statistically significant difference in mean operative time, rate of blood transfusion, and mean number of renal punctures between different Guy’s scores, with all of them showed the highest values at GS IV. There was significant correlation between increase in the grade of GS and the need for re-PCNL and auxiliary procedures. The final stone free rate (SFR) was 93% and complication rate was 27% with significant increase in the immediate success rate, SFR, and complication rate with advancement of the grade of GSS.Conclusion: GSS has a positive correlation with SFR, re-treatment rate, need for auxiliary procedure, and rate of complication

Polymorphic characterisation of gallinacin candidate genes and their molecular associations with growth and immunity traits in chickens

1.Four gallinacin (GAL) genes were assessed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) to characterise these genes in Fayoumi (F) and Rhode Island Red (R) breeds and their crosses of Rhode Island Red × Fayoumi (½R½F) and Fayoumi × Rhode Island Red (½F½R). 2.Genes examined were GAL2, GAL3, GAL4 and GAL5. The molecular associations between the SNPs of the gallinacin genes and body weight, caecal bacterial count and the serum antibody titres of IgA, IgG and IgM were determined. In the R breed, the frequency of TC genotype was higher than TT and CC genotypes for the GAL3 gene. The GG genotype frequency was higher than AA and AG genotypes for the GAL4 gene in the other genetic groups, and the CA genotype frequency was higher than CC and AA genotypes in crosses for the GAL5 gene. 3.In all populations, the frequency of the C allele was higher than the T allele for the GAL3 gene, the G allele was higher than the A allele for the GAL4 gene and the C allele was higher than the A allele for the GAL5 gene. The observed heterozygosity in R, ½R½F and ½F½R was 0.476, 0.375 and 0.158 for the GAL3 gene, 0.458, 0.615 and 0.250 for the GAL4 gene and 0.053, 0.792 and 0.739 for the GAL5 gene, while the expected heterozygosities were 0.490, 0.430 and 0.145 for the GAL3 gene, 0.430, 0.348 and 0.219 for the GAL4 gene and 0.229, 0.478 and 0.496 for the GAL5 gene, respectively. 4.On a molecular level, the genotype TT was significantly higher for body weight than TC and CC genotypes in the GAL3 gene. Birds with the GG genotype had a significantly lower Salmonella typhimurium count than birds with AA genotype in the GAL4 gene. Birds with the genotype AA had higher significant body weights than those with CC and CA genotypes in the GAL5 gene. 5.The results indicated that the GAL3, GAL4 and GAL5 genes are potential candidates for selection programmes to improve S. typhimurium resistance and body weight in chickens