Phonon-induced spin relaxation of conduction electrons in aluminum

Spin-flip Eliashberg function $\alpha_S^2F$ and temperature-dependent spin relaxation time $T_1(T)$ are calculated for aluminum using realistic pseudopotentials. The spin-flip electron-phonon coupling constant $\lambda_S$ is found to be $2.5\times 10^{-5}$. The calculations agree with experiments validating the Elliott-Yafet theory and the spin-hot-spot picture of spin relaxation for polyvalent metals.Comment: 4 pages; submitted to PR

Spin relaxation of conduction electrons in polyvalent metals: A realistic calculation

Relaxation of electronic spins in metals is significantly enhanced whenever a Fermi surface crosses Brillouin zone boundaries, special symmetry points, or lines of accidental degeneracy. A realistic calculation shows that if aluminum had one valence electron, its spin relaxation would be slower by nearly two orders of magnitude. This not only solves a longstanding experimental puzzle, but also provides a way of tailoring spin dynamics of electrons in a conduction band.Comment: 12 pages, 3 figures; to appear in PR

School Choice and Vocational Guidance for Schoolchildren with Chronic Diseases and Other Health Problems

Osim praćenja rasta, razvoja i zdravstvenog stanja učenika tijekom školovanja, liječnik školske medicine razmišlja i o njihovu profesionalnom razvoju. Posebnu pozornost zahtijevaju učenici s kroničnim bolestima, kojih je prema istraživanjima 10 % do 15 %. Prije izbora zanimanja potrebno je upoznati roditelje i učenike s ograničenjima koja proizlaze iz prirode bolesti ili stanja. To omogućuje učenicima da razviju interes za zanimanja za koja nemaju kontraindikaciju. Sistematski pregled u osmom razredu osnovne škole procjena je učenikovih psihofi zičkih sposobnosti za nastavak srednjoškolskog obrazovanja. Tijekom pregleda provodi se profesionalno informiranje za sve učenike. Učenici s kroničnim bolestima, teškoćama u razvoju i drugim poremećajima zdravlja upućuju se na profesionalno usmjeravanje. Cilj ovog rada bio je prikaz razloga upućivanja na školsko i profesionalno usmjeravanje učenika osmih razreda, deset osnovnih škola iz Varaždinske županije, u razdoblju od školske godine 1998./99. do 2007./08. Od ukupno 4939 pregledanih učenika, na profesionalno usmjeravanje bilo je upućeno njih 458 (9,3 %). Najčešći razlozi upućivanja bili su bolesti i stanja iz skupine duševnih poremećaja i poremećaja ponašanja, sa zastupljenošću od 41,3 %. Preporuke stručnog tima za profesionalno usmjeravanje za daljnje školovanje nije slijedilo 10,5 % učenika. Za učenike s kroničnim bolestima i drugim poremećajima zdravlja bilo bi potrebno osigurati dovoljan broj upisnih mjesta u srednjim školama te kontinuirano pratiti njihov profesionalni razvoj radi intervencije u slučaju potrebe promjene škole i uvida u ishod obrazovanja. To bi se postiglo koordiniranim radom školskih liječnika, timova za profesionalno usmjeravanje, srednjih škola i županijskih upravnih odjela za prosvjetu, kulturu i šport.By following a child’s growth, development, and health, school medicine specialist can see opportunities for career choice. Special attention is needed for schoolchildren with chronic diseases and developmental difficulties, because of limited occupation choices. Studies report 10 % to 15 % prevalence of chronic diseases among schoolchildren. Parents and children should be informed about child’s limitations before career choice. It would be helpful for the students to develop interests for occupations that are not contraindicated for their condition. Physical examination gives an insight into the psycho-physical abilities of an eighth-grade primary school student for further education. During examination, counselling and vocational guidance is provided for all students with chronic diseases and other health problems. All procedures are oriented to personal abilities and preferences. The aim of this study was to analyse the reasons for vocational guidance in the Varaždin County of Croatia. It included eighth-grade students from ten primary schools from 1998/99 to 2007/08. Of 4939 students, 458 (9.3 %) with chronic diseases and health difficulties were referred to vocational guidance. Of these, 41.3 % were referred due to mental and behavioural disorders. These students were assessed and received a recommendation for at least two occupations. Forty-eight students (10.5 %) did not follow the recommendation. In a coordinated effort, school physicians, vocational guidance experts, and school and local authorities should secure enrollment of students with chronic diseases and health difficulties in secondary schools and follow their development and education to provide them the best available career opportunities