331 research outputs found
Fourier Expansion of the Riemann zeta function and applications
We study the distribution of values of the Riemann zeta function
on vertical lines , by using the theory of Hilbert space.
We show among other things, that, has a Fourier expansion in the
half-plane and its Fourier coefficients are the binomial
transform involving the Stieltjes constants. As an application, we show
explicit computation of the Poisson integral associated with the logarithm of
. Moreover, we discuss our results with respect to the
Riemann and Lindel\"{o}f hypotheses on the growth of the Fourier coefficients.Comment: 21 page
Low fouling conditions in dead-end filtration: Evidence for a critical filtered volume and interpretation using critical osmotic pressure
This paper presents experiments showing the existence of a critical filtered volume (CFV) when operating colloid dead-end filtration. The CFV is here defined as the filtered volume below which there is no irreversible (with respect to a break in the filtration) fouling on the membrane surface: it has thus the same meaning as cross-flow critical flux but applied to a dead-end process. The existence of the CFV is demonstrated when filtering stable latex or clay suspensions in constant-flux filtration experiments with alternating rinses: in contradiction to the current view, an irreversible deposit is not formed as soon as dead-end filtration begins. This critical filtered volume is shown to be dependent on the suspension stability and to be fully linked to the permeate flux: for permeate fluxes of 80 and 110 l h−1 m−2 the CFV is, respectively, 82 and 65 l m−2 for latex particles. Analyses of results are made by depicting the transition between concentration polarisation and deposit formation considering a critical osmotic pressure, which appears to be a characteristic of the fouling potential of a suspension. The results are discussed in the light of how this concept could lead to an interesting way to control and develop a strategy to operate filtration in dead-end mode
Self-Partial and Dynamic Reconfiguration Implementation for AES using FPGA
This paper addresses efficient hardware/software implementation approaches for the AES (Advanced Encryption Standard) algorithm and describes the design and performance testing algorithm for embedded system. Also, with the spread of reconfigurable hardware such as FPGAs (Field Programmable Gate Array) embedded cryptographic hardware became cost-effective. Nevertheless, it is worthy to note that nowadays, even hardwired cryptographic algorithms are not so safe. From another side, the self-reconfiguring platform is reported that enables an FPGA to dynamically reconfigure itself under the control of an embedded microprocessor. Hardware acceleration significantly increases the performance of embedded systems built on programmable logic. Allowing a FPGA-based MicroBlaze processor to self-select the coprocessors uses can help reduce area requirements and increase a system's versatility. The architecture proposed in this paper is an optimal hardware implementation algorithm and takes dynamic partially reconfigurable of FPGA. This implementation is good solution to preserve confidentiality and accessibility to the information in the numeric communication
Mechanical Behavior of High-Performance Concrete under Thermal Effect
Several studies on the behavior of concrete at high temperatures are the subject of recent concerns, following the latest fires in various European tunnels. In these extreme conditions, significant degradations of concrete structures can be observed (peeling, cracking, breaking of the structure). A priori prediction of concrete behavior during this type of stress is therefore essential and is not possible without a good understanding of the different mechanisms of concrete damage at high temperatures. These mechanisms are often considered as the main causes of cracking and peeling of concrete subjected to high temperatures. Therefore, a fire can strongly modify the behavior of concrete and jeopardize the stability of concrete. In case of fires, it is necessary to know the instantaneous and residual behavior of concrete subjected to temperatures up to 1000°C. In this work we present a study of the mechanical performance of high-temperature high-performance concrete (HPC) exposed to four maximum temperatures, 200, 400, 600, and 900°C. The results obtained show that the mechanical strength at 28 days increases with the degree of temperature compared with that measured at 20°C. On the contrary, a clear decrease is observed between 600 and 900°C
Diverticule congénital de la vessie chez un enfant de 13 ans diabétique en sepsis à point de départ urinaire
Pan African Medical Journal 2013; 14:5
The Effect of Learning on Assembly Line Balancing: A Review
Classical assembly line balancing (ALB) models assume constant cycle times during production. However, this assumption oversimplifies the actual situation, especially in small batch production of up to a few hundred units, since employees can significantly improve their performance thanks to the learning effect, causing task times to decrease. Several researchers have realised the importance of the effect of learning in ALB. However, only a limited number of papers have so far addressed this issue. This is problematic, since ignoring the learning effect in ALB may lead to inaccurate results and by extension misleading conclusions. This study summarises the main contributions in the field of ALB that focus on the learning effect. First, assembly lines (ALs) and ALB problems are characterised. Next, the importance of the learning effect in ALB is highlighted, and the main learning curve (LC) models are introduced. Finally, an exhaustive review of the main contributions in the field of ALB and learning effect is provided. The results highlight that many problems in this area need to be investigated further, in relation to both conceptual model building and the development of algorithms for solving practical size problems
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