When the guard honey bees, Apis mellifera L., form a clump at the hive entrance or on the flight board, the oriental hornet, Vespa orientails L., either creeps toward the clump or hovers over it in order to take a bee. Once the hornet creeps, only few bees facing the hornet become alert, rock their heads and antennae, open their wings, and take a posture of defense. The rest of the clump stays listless without any signal of concern. However, the clump stays dense and the defending bees do not detach themselves neither from the rest of the clump nor from each other. For this reason, it is very difficult for the hornet to grab a bee unless the latter makes a “mistake” by detaching herself from other adjacent bees. If the hornet grabs such a bee, the other defending bees will not attack the hornet to free that bee even when the latter is one centimeter from the others. The defending bees can capture the hornet only when the latter grabs one of them which stands very close to the others. The hornet seems very “aware” of such a situation; hence she seldom becomes a captive. On the other hand, hovering over the clump makes it easier for the hornet to grab a bee. The hovering puts all the clump, rather than part of it, on alert. If the hornet is persistent, which is not often the case, then the clump will no longer be dense. The bees will panicly disperse all over the flight board; hence the hornet can find a detached bee and grabs it easily. The hornet also waits on wing in front of the hive to capture an outgoing or incoming flying bee but the latter usually maneuver to escape. Also, foraging bees reduce their activity during main hours of hornet presence. Among the main factors reducing the hornet impact are the continuous chasing of hornets to each other and the non-persistent attempts of the hornets when they attack bee clumps.
This paper is dealing with an experimental study to show the influence of the geometric characteristics of the vortex generators VG son the thickness of the boundary layer (∂) and drag coefficients (CD) of the flat plate. Vortex generators work effectively on medium and high angles of attack, since they are "hidden" under the boundary layer and practically ineffective at low angles.
The height of VGs relative to the thickness of the boundary layer enables us to study the efficacy of VGs in delaying boundary layer separation. The distance between two VGs also has an effect on the boundary layer if we take into
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In The Bluest Eye (1970), the American-African writer, Toni Morrison explores how
Western standards of ideal beauty are created and propagated with and among the black
community. The novel not only portrays the lives of those whose dark skinned and Negroid
features blight their lives; it also shows how the standard of white beauty, when imposed on
black youth, can drastically damage one’s self-love and esteem which usually occurs when
beauty goes unrecognized. Morrison in this novel focuses on the damage that the black
women characters suffer through the construction of femininity in a racialised society where
whiteness is used as a standard of beauty.
Kurdish language multifunctional morphemes indicate the different functional morphological, syntactical, and semantic tasks of the morphemes. The present study discusses the multifunctional task of the Morpheme Le in Kurdish Language. The Morpheme Le has marginally been included in other studies, yet up to the present times, there has not been a research inclusively dedicated to thoroughly discuss and clarify its multifunctional aspects. The present study is divided into two chapters: Chapter one discusses the theoretical aspect of chapter two that is entirely concerned with the practical aspect of the morpheme Le. The first part of chapter one sheds light on the morphological aspect of the morpheme while part two discusses
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Cryptographic applications demand much more of a pseudo-random-sequence
generator than do most other applications. Cryptographic randomness does not mean just
statistical randomness, although that is part of it. For a sequence to be cryptographically
secure pseudo-random, it must be unpredictable.
The random sequences should satisfy the basic randomness postulates; one of them is
the run postulate (sequences of the same bit). These sequences should have about the same
number of ones and zeros, about half the runs should be of length one, one quarter of length
two, one eighth of length three, and so on.The distribution of run lengths for zeros and ones
should be the same. These properties can be measured determinis
In The Bluest Eye (1970) , Toni Morrison addresses a timeless problem of white racial dominance in the United States and points to the impact it has on the life of black females growing up in the 1930's. Morrison in this novel explores how Western standards of ideal beauty are created and propagated with and among the black community. The novel not only portrays the lives of those whose dark skinned and negroid features blight their lives; it also shows how the standards of white beauty are imposed on black youth to cause a damage of one's self-love and esteem which usually occurs when beauty goes unrecognized
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