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

China occupies an area of 906 million square km. and lies east Asia. Its population approximately 1,388 people, according to census 2010. China was a global great power for centuries , then shrank its jurisdiction and occupied by European countries and Japan in the 19th century. It regained its strength and independence under the leadership and rule of the Chinese Communist Party since 1949. In the 21st century , the Chinese positions has risen universally due to its achievements in the economic and trade affairs . Nowadays, China became a largest exporting state in the world and a second economic power after USA.

The Light and the Dark is the fourth novel in a series written by Charles Percy Snow where it tackles a phase of gifted scholar and remarkable individual Roy Calvert as he search for a source of power and meaning in life to relieve his inner turmoil. The character Roy Calvert is based on Snow's friend, Charles Allbery who exposes the message the character of Roy intends to convey in a certain phase of his life and the prophecy the novel carries amid catastrophe so widespread in the thirties of the twentieth century

Although the events of September 2001 marked the United States' employment of solid forces in its direct comprehensive strategy to counter terrorist organizations and any other challenges to US national security, the United States did not lose sight of the importance of the cultural variable. The cultural variable is the United States' most important instrument of soft power in ensuring its dominance of the international system and promoting its global project. France viewed US soft power as a threat to its own civilizational pattern. Therefore, France considers culture to be an inherent component of its national personality and a cornerstone of its international standing as a major force. Additionally, the US-French political and economic

With the advancement of modern radiotherapy technology, radiation dose and dose distribution have significantly improved. as part of Natural development, interest has recently been renewed by treatment, especially in the use of heavy charged particles, because these radiation types serve theoretical advantages in all biological and physical aspects. The interactions of alpha particle with matter were studied and the stopping powers of alpha particle with Bone Tissue were calculated by using Zeigler’s formula and SRIM software, also the Range for this particle were calculated by using Mat lab language for (0.01-1000) MeV alpha energy.

In this research a new system identification algorithm is presented for obtaining an optimal set of mathematical models for system with perturbed coefficients, then this algorithm is applied practically by an “On Line System Identification Circuit”, based on real time speed response data of a permanent magnet DC motor. Such set of mathematical models represents the physical plant against all variation which may exist in its parameters, and forms a strong mathematical foundation for stability and performance analysis in control theory problems.

The integration of decision-making will lead to the robust of its decisions, and then determination optimum inventory level to the required materials to produce and reduce the total cost by the cooperation of purchasing department with inventory department and also with other company^,s departments. Two models are suggested to determine Optimum Inventory Level (OIL), the first model (OIL-model 1) assumed that the inventory level for materials quantities equal to the required materials, while the second model (OIL-model 2) assumed that the inventory level for materials quantities more than the required materials for the next period.             &nb

  Survival analysis is the analysis of data that are in the form of times from the origin of time until the occurrence of the end event, and in medical research, the origin of time is the date of registration of the individual or the patient in a study such as clinical trials to compare two types of medicine or more if the endpoint It is the death of the patient or the disappearance of the individual. The data resulting from this process is called survival times. But if the end is not death, the resulting data is called time data until the event. That is, survival analysis is one of the statistical steps and procedures for analyzing data when the adopted variable is time to event and time. It could be d

As s widely use of exchanging private information in various communication applications, the issue to secure it became top urgent. In this research, a new approach to encrypt text message based on genetic algorithm operators has been proposed. The proposed approach follows a new algorithm of generating 8 bit chromosome to encrypt plain text after selecting randomly crossover point. The resulted child code is flipped by one bit using mutation operation. Two simulations are conducted to evaluate the performance of the proposed approach including execution time of encryption/decryption and throughput computations. Simulations results prove the robustness of the proposed approach to produce better performance for all evaluation metrics with res