Efficient production of polar molecular Bose-Einstein condensates via an all-optical R-type atom-molecule adiabatic passage

We propose a scheme of "$R$-type" photoassociative adiabatic passage (PAP) to create polar molecular condensates from two different species of ultracold atoms. Due to the presence of a quasi-coherent population trapping state in the scheme, it is possible to associate atoms into molecules with a \textit{low-power} photoassociation (PA) laser. One remarkable advantage of our scheme is that a tunable atom-molecule coupling strength can be achieved by using a time-dependent PA field, which exhibits larger flexibility than using a tunable magnetic field. In addition, our results show that the PA intensity required in the "$R$-type" PAP could be greatly reduced compared to that in a conventional "$\Lambda$-type" one.Comment: 17 pages, 5 figures, to appear in New Journal of Physic

Improving the first-generation students’ alumni awareness at Sol Plaatje University

This research study aimed to improve the alumni awareness of FGS at Sol Plaatje University in order to enjoy a lifelong connection with their alma mater. Furthermore, this study provides recommendations to Sol Plaatje University on how engage first-generation students (FGS) and alumni more effectively in the future. This study used a mixed-method research design to collect and analyse data. The first phase of data collection used a quantitative research method in the form of a survey to obtain biographical information about the final-year students and to identify FGS as key participants for this study. The second data collection phase employed qualitative research to gain insight into alumni awareness among FGS through an alumni awareness workshop and a follow-up questionnaire. The survey findings revealed that students needed to be informed about alumni and related activities on campus. In addition, all were eager to attend the alumni workshop in the second phase of the study. The study findings revealed that FGS showed improved knowledge of alumni and related activities after attending the alumni awareness workshop. They also indicated their willingness to attend university alumni events such as reunions, homecoming, and fundraising events after graduation. Recommendations include suggestions for Sol Plaatje University to identify FGS at registration and tailor its extracurricular and support programmes to cater for such students. The university should also introduce alumni awareness workshops to prepare students for life after graduation as alumni and for the world of work. Lastly, the university should develop a mentoring programme for its FGS and alumni at an earlier stage to help them transition into and out of the university.Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 202

The influence of the type of polymerization upon the discoloration of composites

Na stabilnost kompozita utječe sastav materijala, način polimerizacije, obrada površine, poroznost, izloženost sunčevom svjetlu, prehrana i higi­jena. Jednokomponentni materijal Heliosit i dvokomponentni Isopast pod­vrgnuti su ubrzanom starenju, da bi se metodom spektrofotometrijske refleksije utvrdila sklonost promjeni boje in vitro. Dvokomponentni ma­terijal je potamnio, što je u skladu s kliničkim iskustvom, uz izraženu poroznost. Jednokomponentni materijal je pokazao bolju stabilnost boje, a neki uzorci izbijeljenja zbog nepotpune polimerizacije. Grubo obrađeni uzorci se doimlju svjetlijima, a razlika u promjeni boje između uzorka poliranih na dva različita načina nije opažena.Color stability of composite resin materials is influenced by composition of the material, type of curing, porosity, sunlight exposure, diet, and the oral hygiene. Light cured composite material Heliosit and chemically cured isosit were analysed under conditions of accelerated aging. Differences in color change were established between these two ma­terials using the method of spectrophotometric reflection. Isopast beca­me signifficantly darker and more porous, what is in agreement with clinical experience. Heliosit has shown better color stability, and some samples blanching because of the incomplete polymerisation. The sam­ples with rough surfaces appeared linghter, and the manner of polishing have not caused differencies in color change between analysed samples

Formation of ultracold metastable RbCs molecules by short-range photoassociation

Ultracold metastable RbCs molecules are observed in a double species MOT through photoassociation near the Rb(5S$_{1/2}$)+Cs(6P$_{3/2}$) dissociation limit followed by radiative stabilization. The molecules are formed in their lowest triplet electronic state and are detected by resonant enhanced two-photon ionization through the previously unobserved $(3)^{3}\Pi \leftarrow a^{3}\Sigma^{+}$ band. The large rotational structure of the observed photoassociation lines is assigned to the lowest vibrational levels of the $0^+,0^-$ excited states correlated to the Rb(5P$_{1/2}$)+Cs(6S$_{1/2}$) dissociation limit. This demonstrates the possibility to induce direct photoassociation in heteronuclear alkali-metal molecules at short internuclear distance, as pointed out in [J. Deiglmayr \textit{et al.}, Phys. Rev. Lett. \textbf{101}, 13304 (2008)]