Stirring the Embers: High Sensitivity VLBI Observations of GRB030329

We present high sensitivity Very Long Baseline Interferometry (VLBI) observations 806 days after the gamma-ray burst of 2003 March 29 (GRB030329). The angular diameter of the radio afterglow is measured to be 0.347 +- 0.09 mas, corresponding to 0.99 +- 0.26 pc at the redshift of GRB030329 (z = 0.1685). The evolution of the image size favors a uniform external density over an R^-2 wind-like density profile (at distances of R >~10^18 cm from the source), although the latter cannot be ruled out yet. The current apparent expansion velocity of the image size is only mildly relativistic, suggesting a non-relativistic transition time of t_NR ~ 1 yr. A rebrightening, or at least a significant flattening in the flux decay, is expected within the next several years as the counter-jet becomes visible (this has not yet been observed). An upper limit of <1.9c is set on the proper motion of the flux centroid.Comment: 16 pages, 5 figures, accepted for publication in Astrophysical Journa

Proses Belajar Siswa dalam Meningkatkan Kemampuan Berpikir Kritis Mata Pelajaran Ekonomi SMA

The purpose of this study is: (1) Know the process of students in the learning economy. (2) Determine the efforts of students to improve students' critical thinking skills on economic subjects. (3) Know the teachers' efforts in motivating students to think critically on economic subjects. The research results have been obtained in the field said that the students of class XI IPS in SMAN 5 Malang and in high school Malang Panjura have critical thinking skills are diverse and differ in the learning process in schools, especially in economy class learning. The results of the interview obtained the opinion that the students' critical thinking skills are the attitudes of students in thinking reflex that responds to the subject matter of economics. for something that is not as usual, not in general, and not as routine. It means that something is not the same and the addition of new innovations to show it's creativity.Tujuan penelitan ini adalah (1) mengetahui proses belajar siswa dalam pembelajaran ekonomi; (2) mengetahui upaya yang dilakukan siswa untuk meningkatkan kemampuan berpikir kritis siswa pada mata pelajaran ekonomi; (3) mengetahui USAha guru dalam memberikan motivasi siswa untuk mampu berpikir kritis pada mata pelajaran ekonomi. Hasil penelitian yang telah diperoleh di lapangan menyebutkan bahwa siswa kelas XI IPS di SMA Negeri 5 Malang maupun di SMA Panjura Malang memiliki kemampuan berpikir kritis yang berbeda dalam proses pembelajaran Ekonomi di sekolah, khususnya dalam pembelajaran kelas. Hasil wawancara diperoleh pendapat bahwa kemampuan berpikir kritis siswa adalah sikap siswa dalam berpikir secara reflek yang merespon materi pelajaran Ekonomi, untuk sesuatu yang tidak seperti biasa, tidak pada umumnya, dan tidak seperti rutinitas. Maksudnya bahwa sesuatu yang tidak sama dan adanya tambahan inovasi baru menunjukkan kreativitas

3d polyaniline nanofibers anchored on carbon paper for high-performance and light-weight supercapacitors

In the field of advanced energy storage, nanostructured Polyaniline (PANI) based materials hold a special place. Extensive studies have been done on the application of PANI in supercapacitors, however, the structure–property relationship of these materials is still not understood. This paper presents a detailed characterization of the novel sodium phytate doped 3D PANI nanofibers anchored on different types of carbon paper for application in supercapacitors. An excellent relationship between the structures and properties of the synthesized samples was found. Remarkable energy storage characteristics with low values of solution, charge transfer and polarization resistance and a specific capacitance of 1106.9 ± 1.5 F g$^{−1}$ and 779 ± 2.6 F g$^{−1}$ at current density 0.5 and 10 Ag$^{−1}$, respectively, was achieved at optimized conditions. The symmetric supercapacitor assembly showed significant enhancement in both energy density and power density. It delivered an energy density of 95 Wh kg$^{−1}$ at a power of 846 W kg$^{−1}$. At a high-power density of 16.9 kW kg$^{−1}$, the energy density can still be kept at 13 Wh kg$^{−1}$. Cyclic stability was also checked for 1000 cycles at a current density of 10 Ag$^{−1}$ having excellent retention, i.e., 96%

PROMIS MCID and SCB Achievement in Rotator Cuff Repair

The purpose of this study was to establish threshold score changes to determine minimal clinically important difference (MCID) and substantial clinical benefit (SCB) in PROMIS computer adaptive test (CAT) scores following rotator cuff repair (RCR). Patients undergoing arthroscopic RCR were identified over a 24-month period. PROMIS CAT forms for upper extremity physical function (PROMIS-UE), pain interference (PROMIS-PI), and depression (PROMIS-D) were utilized. Analysis of variance testing with post hoc least significant difference pairwise comparisons and Tukey’s B subset analysis were used in determining if anchor question responses showed statistically significant differences between answers. These findings were used to establish two clinically significant outcome (CSO) groups, MCID and substantial clinical benefit (SCB). Patients were then dichotomized into two separate analyses, no MCID achievement compared with MCID achievement and no SCB achievement compared with SCB achievement. Of the 198 eligible patients, 168 patients (84.8%) were included in analysis. Receiver operating curve analysis determined delta PROMIS-UE values of 5.8 and 9.7 (area under the curve (AUC) = 0.906 and 0.949, respectively) and delta PROMIS-PI values of -11.4 and -12.9 (AUC = 0.875 and 0.938, respectively) to be excellent threshold predictors of MCID and SCB achievement. On average, 81.1%, 65.0%, and 54.5% of patients achieved MCID for PROMIS-UE, PROMIS-PI, and PROMIS-D while 70.7%, 60.7%, and 37.7% of patients in the cohort respectively achieved SCB

Sensitivity to vapors of ethanol of thin films of SnO2 alloyed by fluorine after isothermal annealing

Films of tin oxide are intensively used as a sensitive element of sensors for the determination of various gases in atmospheric air [1]. The principle of operation of these sensors is based on the modulation of the near-surface space charge region and the change in the electrical resistivity of film crystals upon adsorption of gas molecules. In order for physicochemical processes to proceed quickly on the surface of the sensitive layer, providing a response time of several seconds, the sensor is heated to a temperature of 100-450 ° C, which "activates" its surface. Sensors are used by environmental services, chemical enterprises, in oil and gas industry - wherever it is necessary to make express measurements of the concentrations of such gases as: propane, methane, hydrogen, vapors of ethyl alcohol. For a long time, thin films are in a state heated to 400°C. Determining how long the film can retain its useful properties in the operating mode is an actual scientific and practical task

Nanofiber fabrication in a temperature and humidity controlled environment for improved fibre consistency

To fabricate nanofibers with reproducible characteristics, an important demand for many applications, the effect of controlled atmospheric conditions on resulting electrospun cellulose acetate (CA) nanofibers was evaluated for temperature ranging 17.5 - 35&#xb0;C and relative humidity ranging 20% - 70%. With the potential application of nanofibers in many industries, especially membrane and filter fabrication, their reproducible production must be established to ensure commercially viability.&#xd;&#xa;Cellulose acetate (CA) solution (0.2 g/ml) in a solvent mixture of acetone/DMF/ethanol (2:2:1) was electrospun into nonwoven fibre mesh with the fibre diameter ranging from 150nm to 1&#xb5;m.&#xd;&#xa;The resulting nanofibers were observed and analyzed by scanning electron microscopy (SEM), showing a correlation of reducing average fibre diameter with increasing atmospheric temperature. A less pronounced correlation was seen with changes in relative humidity regarding fibre diameter, though it was shown that increased humidity reduced the effect of fibre beading yielding a more consistent, and therefore better quality of fibre fabrication.&#xd;&#xa;Differential scanning calorimetry (DSC) studies observed lower melt enthalpies for finer CA nanofibers in the first heating cycle confirming the results gained from SEM analysis. From the conditions that were explored in this study the temperature and humidity that gave the most suitable fibre mats for a membrane purpose were 25.0&#xb0;C and 50%RH due to the highest level of fibre diameter uniformity, the lowest level of beading while maintaining a low fibre diameter for increased surface area and increased pore size homogeneity. This study has highlighted the requirement to control the atmospheric conditions during the electrospinning process in order to fabricate reproducible fibre mats

Improving water productivity, reducing poverty and enhancing equity in mixed crop-livestock systems in the Indo-Gangetic Basin

The “Improving water productivity, reducing poverty and enhancing equity in mixed crop-livestock systems in the Indo-Gangetic Basin” was designed and conducted by the International Water Management Institute (IWMI), in partnership with international and national partners, to address the relative neglect of livestock water needs of crop-livestock farming systems. The primary objective of this project was to optimize the productive use of water in the crop-livestock farming systems of semi-arid areas to enhance livelihoods, reduce poverty, contribute to gender equity, and protect the environment. This was addressed through an integrated approach led by a multi-disciplinary team across three States of the Ganga Basin

Exploring the factors affecting MOOC retention: a survey study

Massive Open Online Courses (MOOCs) hold the potential to open up educational opportunities to a global audience. However, evidence suggests that only a small proportion of MOOC participants go on to complete their courses and relatively little is understood about the MOOC design and implementation factors that influence retention. This paper reports a survey study of 379 participants enrolled at university in Cairo who were encouraged to take a MOOC of their own choice as part of their development. 122 participants (32.2%) went onto to complete an entire course. There were no significant differences in completion rates by gender, level of study (undergraduate or postgraduate) or MOOC platform. A post-MOOC survey of students’ perceptions found that MOOC Course Content was a significant predictor of MOOC retention, with the relationship mediated by the effect of content on the Perceived Effectiveness of the course. Interaction with the instructor of the MOOC was also found to be significant predictor of MOOC retention. Overall these constructs explained 79% of the variance in MOOC retention