Doppler images of II Pegasi for 2004-2010

Aims. We study the spot activity of II Peg during the years 2004-2010 to determine long- and short-term changes in the magnetic activity. In a previous study, we detected a persistent active longitude, as well as major changes in the spot configuration occurring on a timescale of shorter than a year. The main objective of this study is to determine whether the same phenomena persist in the star during these six years of spectroscopic monitoring. Methods. The observations were collected with the high-resolution SOFIN spectrograph at the Nordic Optical Telescope. The temperature maps were calculated using a Doppler imaging code based on Tikhonov regularization. Results. We present 12 new temperature maps that show spots distributed mainly over high and intermediate latitudes. In each image, 1-3 main active regions can be identified. The activity level of the star is clearly lower than during our previous study for the years 1994-2002. In contrast to the previous observations, we detect no clear drift of the active regions with respect to the rotation of the star. Conclusions. Having shown a systematic longitudinal drift of the spot-generating mechanism during 1994-2002, the star has clearly switched to a low-activity state for 2004-2010, during which the spot locations appear more random over phase space. It could be that the star is near to a minimum of its activity cycle.Comment: Accepted for publication in Astron. and Astrophys., 8 pages, 5 figure

An observational study of aerosols and tropical cyclones over the eastern atlantic ocean basin for recent hurricane seasons

The aerosol vertical distribution in the tropical cyclone (TC) main development region (MDR) during the recent active hurricane seasons (2015–2018) was investigated using observations from NASA’s Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) Satellite. The Total Attenuated Backscatter (TAB) at 532 nm was measured by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP Lidar) onboard CALIPSO which is a polar orbiting satellite that evaluates the role clouds and atmospheric aerosols play in Earth’s weather, climate and air quality. The TAB was used to illustrate the dispersion and magnitude of the aerosol vertical distribution in the TC-genesis region. A combination of extinction quality flag, cloud fraction, and cloud-aerosol discrimination (CAD) scores were used to filter out the impact of clouds. To better describe the qualitative and quantitative difference of aerosol along the paths of African Easterly Waves (AEWs), the MDR was further divided into two domains from 18◦ W to 30◦ W (Domain 1) and 30◦ W to 45◦ W (Domain 2), respectively. The distribution of average aerosol concentration from the time of active cyclogenesis was compared and quantified between each case. The resulting observations suggest that there are two distinct layers of aerosols in the vertical profile, a near surface layer from 0.5–1.75 km and an upper layer at 1.75–5 km in altitude. A quantification of the total aerosol concentration values indicate domain 2 cases were associated with higher aerosol concentrations than domain 1 cases. The environmental variables such as sea surface temperature (SST), vertical windshear (VWS), and relative humidity (RH) tended to be favorable for genesis to occur. Among all cases in this study, the results suggested tropical cyclone genesis and further development occurred under dust-loaded conditions while the environmental variables were favorable, indicating that dust aerosols may not play a significant role in inhibiting the genesis process of TCs

Teacher trainees’ creativity and cognitive engagement in using mobile technology for video project: a case study

This research investigates the use of mobile technology namely the smart hand phone in developing instructional video project for language learning. The purpose of this study is to analyse students’ creativity and cognitive engagement when developing instructional video through the use of smart hand phone. Firstly, the research attempts to address the relationship between students’ creativity based on ICEDIP (inspiration, clarification, evaluation distillation, incubation and perspiration) and cognitive engagement in mobile learning environment.. Secondly, the research further examines each creativity process in contributing the effect on cognitive engagement. The study employed a mix method of quantitative and qualitative research. A survey using adapted questionnaire was carried out on a focus group of 52 first semester teacher trainees (Bachelor Degree in Education) specializing in English language. Semi structured interviews were carried out on three students in order to gain an in depth understanding of the students’ creativity and cognitive engagement. A correlation analysis was used to identify the relationship between creativity and cognitive engagement. Further analysis of Hierarchical Multiple regression was employed to identify the specific items for creativity process affecting cognitive engagement. The results from the correlation analysis indicate a significant relationship between creativity and cognitive engagement, which is also supported by the interviews. Student’s creativity has contributed to a meaningful learning when smart hand phone is used for learning. Further findings from the interviews show some indicators for the researchers to improve the instructional strategies in future. Implications and discussions are elaborated based on the contribution to the development and design of the curriculum

Analysis of the MOST light curve of the heavily spotted K2IV component of the single-line spectroscopic binary II Pegasi

Continuous photometric observations of the visible component of the single-line, K2IV spectroscopic binary II Peg carried out by the MOST satellite during 31 consecutive days in 2008 have been analyzed. On top of spot-induced brightness modulation, eleven flares were detected of three distinct types characterized by different values of rise, decay and duration times. The flares showed a preference for occurrence at rotation phases when the most spotted hemisphere is directed to the observer, confirming previous similar reports. An attempt to detect a grazing primary minimum caused by the secondary component transiting in front of the visible star gave a negative result. The brightness variability caused by spots has been interpreted within a cold spot model. An assumption of differential rotation of the primary component gave a better fit to the light curve than a solid-body rotation model.Comment: Accepteed to MNRA

Fatigue Crack Growth Assessment and Fatigue Resistance Enhancement of Aluminium Alloys

Fatigue damage of aluminium alloys is one of the key concerns in transport industries, particularly in the aerospace industry. The purpose of the project is to develop new knowledge and techniques against fatigue failure for these industries through a systematic investigation of fatigue resistance and crack growth behaviours of aluminium alloys. Fatigue and fracture mechanics have been investigated analytically, numerically and experimentally in this project. Overload transient effect on fatigue crack growth has been examined by considering various parameters including crack closure, overload ratio (OLR), load ratio ( ratio), baseline stress intensity factor range, (∆ ) and geometry. It was found that crack closure can be correlated qualitatively and quantitatively to all other parameters associated with overload transient behaviour. It is proposed that the effect of crack tip plasticity on the non-linearity of the compliance curve can be separated to obtain reliable crack closure measurement. In this project, different methods are used to better understand the transient retardation process so that the damage tolerance design (DTD) of the components made of aluminium alloys can be enhanced. Another important parameter for fatigue and damage tolerance design (DTD) of engineering components is the threshold stress intensity factor range for fatigue crack growth, ∆ ℎ. A small variation in identification of ∆ ℎ can lead to a big change in overall estimation of fatigue life. In this project, an analytical model has been developed for aluminium alloys by fitting an analytical curve with raw crack growth data in order to identify the ∆ ℎ. This model has the capacity to identify ∆ ℎ for different aluminium alloys at various ratios. There is a great demand for enhanced fatigue life of aluminium alloys in the transport industry. This project has carried out a detailed investigation of electromagnetic treatment (ET) in the form of electropulsing treatment to develop an efficient technique for fatigue resistance enhancement. ET parameters including the treatment intensity, treatment time and the number of applications have been optimised. It is suggested that the duration of ET treatment can be used as the main parameter among all these to control the fatigue resistance of the aluminium alloy. The improvement in fatigue resistance has been explained by the change in microhardness and conductivity of aluminium alloy due to ET. Additionally, the fracture morphology was analysed using scanning electron microscopy (SEM). The precipitates and dislocation characteristics were also studied using transmission electron microscopy (TEM). The outcomes of this investigation will help improve structural integrity by enhancing fatigue resistance of aluminium alloys

Assessment of Evolving Conjunction Risk for Small Satellite Missions

This study presents an assessment of evolving conjunction risk for small satellite missions (5U or smaller) by using the suite of LeoLabs\u27 products. The aim is to (1) quantify the growth of small satellites population in the low Earth orbit (LEO), (2) assess the impact of on-orbit break-up events and small debris (sub-10 cm) objects on small satellite missions, and (3) present an optimal risk mitigation timeline for small satellite missions, based on conjunction alerts issued in 2023. The global network of S-band radars built and operated by LeoLabs provides a 24/7 data feed to power this assessment and help identify the evolution of this risk. The ability to access this enhances operational safety. Thus, a statistical assessment of the risk posed and quantification of the evolution of this risk over mission timeline is important. Further, understanding the optimal risk mitigation timeline for small satellite missions is critical as these missions have limited on-board resources and hence, knowing the severity of the risk and taking appropriate and timely mitigative action (attitude change or thrusting \u27n\u27 days before time of closest approach, i.e., TCA) is paramount. Although, the mitigative action (the level and duration of thrusting or the amount of attitude change) itself is not studied as these specifics often vary based on the event type, the optimal timeline (as in how many days before TCA?) of this mitigative action is reviewed by studying the conjunction events encountered by small satellites

Military Parade in Washington, D.C. following Operation Desert Storm

The black and white photo depicts a military parade held in Washington, D. C., following Operation Desert Storm. The Lincoln Memorial is can be seen in the background.https://scholarsjunction.msstate.edu/fvw-artifacts/3189/thumbnail.jp

Research culture among academics at higher education institutions: a case study at the International Islamic University Malaysia

Academic research has been converted into a basic element of the mission of universities, through which they contribute to the success of regional, economic, cultural and educational development plans. Thus, the success of a university today is likely being measured through the number of research, publications and intellectual properties produced by academic staff. Therefore, this study attempts to investigate the existence of research culture at the International Islamic University of Malaysia (IIUM) and examines academic staff perceptions toward it. It employed a survey method to gather the data. A survey was administered to a sample of academic staff at all Kulliyyahs (Faculties), Institutes and Centers at IIUM. A number of 411 academic staff participated as respondents in this study. A set of questionnaire consisting of 39 items was constructed to examine the research culture at IIUM. Where as a simple descriptive statistical analysis which includes percentages, frequencies and means was used for data analysis. The outcomes of this research are that tangible practical implications have emerged from the data analysis and the discussions. It is evident that academics are prepared to practice the research culture at IIUM, as well as their dispositions to engage in intellectual discourse. The academic staff are aware of the importance of research, the procedure of conducting research and that they believe that by doing research, their teaching competencies can be further improve

Essential skills in call class: enhancing searching and language skills

Introduction: In the quest of making learning more relevant in the contemporary era of information and communication technology, the Internet is considered a valuable resource to both language teachers and learners (Singhal, 1997). With the World Wide Web (WWW), learners of many languages have access to an unprecedented amount of authentic target language information (Warschauer, 1998; Chun and Plass, 2000). The Internet offers a great deal of supplemental language activities for the teachers to select from and later these activities provide the students with additional practices in a specific area of language learning (Chafe, 1999). The content of the Internet is generally very current and the language used to present it is real and authentic (Brown, 1999). Moreover, the use of the Internet should be endorsed as a tool to be incorporated into classroom activity as it stimulates active learning where the students' language skills and their language learning experience would be enhanced (Wetzel and Chisholm, 1998). The activities can be equally enjoyed by both advanced and slow learners