A piezoelectric cantilever beam with a tip mass at its free end is a common energy harvester configuration. This article introduces a new principle of designing such a harvester that increases the generated power without changing the resonance frequency of the harvester: the attraction force between two permanent magnets is used to add stiffness to the system. This magnetic stiffening counters the effect of the tip mass on the efficient operation frequency. Five set-ups incorporating piezoelectric bimorph cantilevers of the same type in different mechanical configurations are compared theoretically and experimentally to investigate the feasibility of this principle: theoretical and experimental results show that magnetically stiffened harve

he assignment model represents a mathematical model that aims at expressing an important problem facing enterprises and companies in the public and private sectors, which are characterized by ensuring their activities, in order to take the appropriate decision to get the best allocation of tasks for machines or jobs or workers on the machines that he owns in order to increase profits or reduce costs and time As this model is called multi-objective assignment because it takes into account the factors of time and cost together and hence we have two goals for the assignment problem, so it is not possible to solve by the usual methods and has been resorted to the use of multiple programming The objectives were to solve the problem of

A steganography hides information within other information, such as file, message, picture, or video. A cryptography is the science of converting the information from a readable form to an unreadable form for unauthorized person. The main problem in the stenographic system is embedding in cover-data without providing information that would facilitate its removal. In this research, a method for embedding data into images is suggested which employs least significant bit Steganography (LSB) and ciphering (RSA algorithm) to protect the data. System security will be enhanced by this collaboration between steganography and cryptography.

Cladosporium sp. plays an important role in human health, it is one of the pathogenic fungi which cause allergy and asthma and most frequently isolated from airborne spores.  In this study, a couple of universal PCR primers were designed to identify the pathogenic fungi Cladosporium sp. according to conserved region 5.8S, 18S and 28S subunit ribosomal RNA gene in Cladosporium species. In silico RFLP-PCR were used to identify twenty-four Cladosporium strains. The results showed that the universal primer has the specificity to amplify the conserved region in 24 species as a band in virtual agarose gel. They also showed that the RFLP method is able to identify three Cladosporium spe

This research aims at investigating pupils’ ability in using discourse markers which are identified in the English textbooks of secondary schools. Four texts are chosen from third intermediate class. The four texts are short stories of different topics.                                                  

        This research hypothesizes that there are no statistical significant differences among Iraqi intermediate pupils’ ability in using textual

Writing plays an effective role in developing one's thinking and
enhancing Learning. It is, in fact, a means of widening one's own views about
the world for the numerous uses that it can serve (Samuel, 1988:28).
In regard to the unquestionable significance of writing in the teaching –
Learning process, the traditional approach seems to be far from being able to
put such significance into practice. Traditionalists give priority to formulating
students' ideas before using prescribed rhetorical framework and then
submitting the written product for grading. Emphasis is, therefore, limited to the
prewriting stage where a certain topic is explored, and the role of the teacher is
confined to assigning the topic and

This study was designed to evaluate the ability of bioemulsifier to inhibit the growth of some pathogenic microorganisms. Fourteen isolates belonged to Serratia sp. were collected and tested for their ability to produce bioemulsifier. Results showed that Serratia marcescens S10 (isolated from the gut of the American cockroach) had the highest ability to produce bioemulsifier, among 14 isolates belong to Serratia spp. and it had the ability to inhibit the growth of some microorganisms. The production of bioemulsifier was detected by determination of emulsification index (E24%), qualitative drop-collapse test, emulsification activity (E.A) and measuring the surface tension (S.T). The results of bioemulsifier produced by Serratia marcescens S1

Sixty-four isolate were klebsiella pneumoniae. Fourteen bacteria isolates “Kelbsiella species” were taken from soil and water hospital in the period between October to December 2018, those isolated were cultured on a blood agar to test their ability to hydrolytic due to formation the inhibition zone . Twenty one isolates of K. pneumoniae were selected to be cultured in mineral salt agarfor testing their efficiency to produce laccase enzyme .The efficient isolate was diagnosed depending on phenotypic, microscopic and biochemical tests to be Klebsiella pneumoniae K7. Laccases (benzenediol: oxygen oxidoreductases; EC: 1.10.3.2) are subfamily of multicopper oxidases (MCOs) from Klebsiellapneumoniae K7 has been partially characterized by