Usability of Web-based Knowledge Portals to support Research Organizations

Usability refers to the effectiveness, efficiency and user satisfaction of a designed product or system. One of the most of productive ways of measuring usability goals is through questionnaires and surveys. In this paper, we discuss usability related issues from a users’ perspective in the design analysis of a web-based knowledge portal that was developed to support the knowledge management activities of an educational research organization. The original portal system initially experienced high levels of user participation. However in recent times, this trend had been reversed with flagging log-in access rates. Consequently, a criterion-based usability survey instrument was designed and implemented online to gather users’ responses and comments. The survey outcomes indicated that a large number of respondents used the portal sporadically with a significant number being completely unaware of many of its services. Thus based upon this feedback, the existing portal was revamped to ensure a more user-centric design model that focused on the cornerstone aspects of user control, ease of navigation, personalization services and clarity in visual presentation of information.Usability refers to the effectiveness, efficiency and user satisfaction of a designed product or system. One of the most of productive ways of measuring usability goals is through questionnaires and surveys. In this paper, we discuss usability related issues from a users’ perspective in the design analysis of a web-based knowledge portal that was developed to support the knowledge management activities of an educational research organization. The original portal system initially experienced high levels of user participation. However in recent times, this trend had been reversed with flagging log-in access rates. Consequently, a criterion-based usability survey instrument was designed and implemented online to gather users’ responses and comments. The survey outcomes indicated that a large number of respondents used the portal sporadically with a significant number being completely unaware of many of its services. Thus based upon this feedback, the existing portal was revamped to ensure a more user-centric design model that focused on the cornerstone aspects of user control, ease of navigation, personalization services and clarity in visual presentation of information

Phonon Anomalies, Orbital-Ordering and Electronic Raman Scattering in iron-pnictide Ca(Fe0.97Co0.03)2As2: Temperature-dependent Raman Study

We report inelastic light scattering studies on Ca(Fe0.97Co0.03)2As2 in a wide spectral range of 120-5200 cm-1 from 5K to 300K, covering the tetragonal to orthorhombic structural transition as well as magnetic transition at Tsm ~ 160K. The mode frequencies of two first-order Raman modes B1g and Eg, both involving displacement of Fe atoms, show sharp increase below Tsm. Concomitantly, the linewidths of all the first-order Raman modes show anomalous broadening below Tsm, attributed to strong spin-phonon coupling. The high frequency modes observed between 400-1200 cm-1 are attributed to the electronic Raman scattering involving the crystal field levels of d-orbitals of Fe2+. The splitting between xz and yz d-orbital levels is shown to be ~ 25 meV which increases as temperature decreases below Tsm. A broad Raman band observed at ~ 3200 cm-1 is assigned to two-magnon excitation of the itinerant Fe 3d antiferromagnet.Comment: Accepted for Publication in JPC

Anomalous Raman scattering from phonons and electrons of superconducting FeSe0.82_{0.82}

We report interesting anomalies in the temperature dependent Raman spectra of FeSe$_{0.82}$ measured from 3K to 300K in the spectral range from 60 to 1800 cm$^{-1}$ and determine their origin using complementary first-principles density functional calculations. A phonon mode near 100 cm$^{-1}$ exhibits a sharp increase by $\sim$ 5% in frequency below a temperature T$_s$ ($\sim$ 100 K) attributed to strong spin-phonon coupling and onset of short-range antiferromagnetic order. In addition, two high frequency modes are observed at 1350 cm$^{-1}$ and 1600 cm$^{-1}$, attributed to electronic Raman scattering from ($x^2-y^2$)to $xz$ / $yz$ $d$-orbitals of Fe.Comment: 19 pages, 4 figures, 1 tabl

Unravelling the potential of nitric acid as a surface modifier for improving the hemocompatibility of metallocene polyethylene for blood contacting devices

Design of blood compatible surfaces is obligatory to minimize platelet surface interactions and improve the thromboresistance of foreign surfaces when they are utilized as biomaterials particularly for blood contacting devices. Pure metallocene polyethylene (mPE) and nitric acid (HNO3) treated mPE antithrombogenicity and hydrophilicity were investigated. The contact angle of the mPE treated with HNO3 decreased. Surface of mPE and HNO3 treated mPE investigated with FTIR revealed no major changes in its functional groups. 3D Hirox digital microscopy, SEM and AFM images show increased porosity and surface roughness. Blood coagulation assays prothrombin time (PT) and activated partial thromboplastin time (APTT) were delayed significantly (P < 0:05) for HNO3 treated mPE. Hemolysis assay and platelet adhesion of the treated surface resulted in the lysis of red blood cells and platelet adherence, respectively indicating improved hemocompatibility of HNO3 treated mPE. To determine that HNO3 does not deteriorate elastic modulus of mPE, the elastic modulus of mPE and HNO3 treated mPE was compared and the result shows no significant difference. Hence, the overall observation suggests that the novel HNO3 treated mPE may hold great promises to be exploited for blood contacting devices like grafts, catheters, and etc

Metallic monoclinic phase in VO2_2 induced by electrochemical gating: in-situ Raman study

We report in-situ Raman scattering studies of electrochemically top gated VO$_2$ thin film to address metal-insulator transition (MIT) under gating. The room temperature monoclinic insulating phase goes to metallic state at a gate voltage of 2.6 V. However, the number of Raman modes do not change with electrolyte gating showing that the metallic phase is still monoclinic. The high frequency Raman mode A$_g$(7) near 616 cm$^{-1}$ ascribed to V-O vibration of bond length 2.06 \AA~ in VO$_6$ octahedra hardens with increasing gate voltage and the B$_g$(3) mode near 654 cm$^{-1}$ softens. This shows that the distortion of the VO$_6$ octahedra in the monoclinic phase decreases with gating. The time dependent Raman data at fixed gate voltages of 1 V (for 50 minute, showing enhancement of conductivity by a factor of 50) and 2 V (for 130 minute, showing further increase in conductivity by a factor of 5) show similar changes in high frequency Raman modes A$_g$(7) and B$_g$(3) as observed in gating. This slow change in conductance together with Raman frequency changes show that the governing mechanism for metalization is more likely to the diffusion controlled oxygen vacancy formation due to the applied electric field.Comment: 5 pages, 6 figure

Effects of Automated Interventions in Programming Assignments: Evidence from a Field Experiment

A typical problem in MOOCs is the missing opportunity for course conductors to individually support students in overcoming their problems and misconceptions. This paper presents the results of automatically intervening on struggling students during programming exercises and offering peer feedback and tailored bonus exercises. To improve learning success, we do not want to abolish instructionally desired trial and error but reduce extensive struggle and demotivation. Therefore, we developed adaptive automatic just-in-time interventions to encourage students to ask for help if they require considerably more than average working time to solve an exercise. Additionally, we offered students bonus exercises tailored for their individual weaknesses. The approach was evaluated within a live course with over 5,000 active students via a survey and metrics gathered alongside. Results show that we can increase the call outs for help by up to 66% and lower the dwelling time until issuing action. Learnings from the experiments can further be used to pinpoint course material to be improved and tailor content to be audience specific.Comment: 10 page