This research aims to examine vacationers’ perceived stress in Colombia. Based on the literature review, following dimensions are examined: (1) transportation at destination –including variables lack of control, insecurity, cleanness, noise, temperature and space; (2) conditions accommodation sleep, distance sightseeing, cleanness quality room, services food; (3) behavior culture locals languag...

In this paper, we characterize the idempotency, cleanness, and unit-regularity of commutator $[E_1, E_2]=E_1E_2-E_2E_1$ involving idempotents $E_1,E_2$ in certain subrings $M_{2}(\mathbb{Z})$.

An element $a$ in a ring $R$ is very clean in case there exists‎ ‎an idempotent $ein R$ such that $ae = ea$ and either $a‎- ‎e$ or $a‎ + ‎e$ is invertible‎. ‎An element $a$ in a ring $R$ is very $J$-clean‎ ‎provided that there exists an idempotent $ein R$ such that $ae =‎ ‎ea$ and either $a-ein J(R)$ or $a‎ + ‎ein J(R)$‎. ‎Let $R$ be a‎ ‎local ring‎, ‎and let $sin C(R)$‎. ‎We prove that $Ain K_...

A ring $R$ is a strongly clean ring if every element in $R$ is the sum of an idempotent and a unit that commutate. We construct some classes of strongly clean rings which have stable range one. It is shown that such cleanness of $2 imes 2$ matrices over commutative local rings is completely determined in terms of solvability of quadratic equations.

TiN and Ti2O3 are the predominant inclusion types in Ti-alloyed ferritic chromium stainless steels. In order to ensure the required steel cleanness level, an effective removal of such inclusions in the slag during secondary metallurgy is essential. This inclusion removal predominantly takes place via dissolution of the inclusion in the slag. The dissolution behavior of TiN and Ti2O3 in CaO-SiO2...

BACKGROUND Patients' and healthcare providers' satisfactions are important outcomes for any healthcare programmes. In Egypt, the Health Sector Reform Program (HSRP) has been implemented since 1999 in primary healthcare (PHC) centres adopting the family health approach. OBJECTIVES To assess the clients' satisfaction towards the overall health services provided by health centres affiliated to H...