An aerobic fluidized bed reactor (FBR) was operated for the removal of methyl tert-butyl ether (MTBE) and benzene, toluene, ethylbenzene, and p-xylene (BTEX) from water. The reactor was seeded with a mixed culture adapted to MTBE. Granular activated carbon (GAC) was used as the biological attachment medium. Influent MTBE to the reactor was 7.8 mg/L MTBE, with a flow rate of 22.7 L/day, and an e...

Mindfulness is the ability of an individual to actively process information surrounding them with the aim of using that information to draw distinctive or novel conclusions. By facilitating mindfulness, businesses can benefi t from having a stronger competitive advantage, increased loyalty, and provide a more meaningful experience to their customers. Mindfulness is a state of awareness that can...

As visitors to national parks diff er in terms of their profi les and needs, an empirical evaluation of the quality of their experiences, if based on a homogeneous sample, may lead to false conclusions and, hence, inappropriate management decisions. Using Paklenica National Park as a case study, this paper aims to provide a more heterogeneous perspective on the defi nition of the quality of vis...

There is described a class of the encryption functions based on data-dependent selection of subkeys. Such functions are proposed for elaboration of the indeterminate ciphers with very large number of different modifications of the cryptalgorithm. A 128bit undetermined cipher is described. The number of possible modifications is ≈ 10, where 2 ≤ R ≤ 7, R is the number of rounds. It is proved that...

A key recovery attack on the stream cipher Achterbahn128/80, a cipher in the second phase of eSTREAM, is given. The key observation is a high dependency between some input bits to the Boolean combining function generating the keystream. It results in the first known attacks on both the 128-bit and the 80-bit variants of the cipher. The amount of keystream bits required in the attacks is less th...

Curriculum Change in South Africa Since 1994 The development of a national curriculum is a major challenge for any nation, and when a whole country depends on it to transform society in one broad stroke, it imposes tremendous expectations on such a curriculum. South Africa’s democratic government has inherited a divided and unequal system of education and must recognise that apartheid is not th...

Voltage Source Converter (VSC) based HVDC is the most recent HVDC technology with extruded DC cables in small and medium power transmission. VSC-HVDC converters include Insulated Gate Bipolar Transistors (IGBT’S) and operated with high frequency Pulse Width Modulation (PWM) in order to get high speed control of both active and reactive power. With VSC-HVDC there is an addition degree of freedom...