Recent Advances in Multiple-Stage Centrifugal Compressors

Centrifugal compressors, sometimes termed radial compressors, are a sub-class of dynamic axisymmetric work-absorbing turbomachinery.

The idealized compressive dynamic turbo-machine achieves a pressure rise by adding kinetic energy/velocity to a continuous flow of fluid through the rotor or impeller. This kinetic energy is then converted to an increase in potential energy/static pressure by slowing the flow through a diffuser. The pressure rise in impeller is in most cases almost equal to the rise in the diffuser section. In the case of where flow simply passesthrough a straight pipe to enter a centrifugal compressor; the flow is straight, uniform and has no vorticity. As illustrated below α1 = 0°. As the flow continues to pass into and through the centrifugal impeller, the impeller forces the flow to spin faster and faster. According to a form of Euler's fluid dynamics equation, known as pump and turbine equation, the energy input to the fluid is proportional to the flow's local spinning velocity multiplied by the local impeller tangential velocity.

In many cases the flow leaving centrifugal impeller is near the speed of sound (340 metres/second). The flow then typically flowsthrough a stationary compressor causing it to decelerate. These stationary compressors are actually static guide vanes where energy transformation takes place. As described in Bernoulli's principle, this reduction in velocity causes the pressure to rise leading to a compressed fluid.

A Comparative Analysis of Social Networking Analysis Tools

The blast of Web 2.0 (online journals, wikis, substance offering destinations, informal communities, and so forth.) opens up new viewpoints for imparting and overseeing data. In this setting, among a few developing exploration fields concerning “Web Intelligence”, a standout amongst the most energizing is the improvement of utilizations spent significant time in the treatment of thesocial measurement of the Web. Especially, building and overseeing virtual groups for Virtual Enterprises require the improvement of another era of apparatuses incorporating interpersonal organization displaying and examination. A very long while back, the first deals with Social Networks Analysis (SNA) was done via specialists in Social Sciences who needed to comprehend the conduct and advancement of human systems. A few pointers were proposed to portray the on-screen characters and additionally the system itself. One of these indicators, for case, was the centrality that can be utilized as a part of showcasing to find the early adopters or the individuals whose action is prone to spread data to numerous individuals in a briefest manner. 

These days, the wide utilization of Internet around the globe permits to join quite a few people. As pointed in the Gartner study, this critical advancement of the systems offers ascend to a developing requirement for informal organization mining and informal community investigation strategies so as to give more profound perception of the system and to distinguish groups and study their development for applications in zones, for example, group advertising, social shopping, suggestion components and personalization sifting or graduated class management. For this reason, while numerous new advancements (wikis, social bookmarks and social labeling, and so on) and administrations (GData, Google Friend Connect, Open Social Face book Beacon) were proposed on web, a few new SNA devices have been created. These instruments are exceptionally valuable todissect hypothetically an interpersonal organization additionally to speak toit graphically. They figure diverse markers which describe the system’s structure, the connections between the performing artists and additionally the position of a specific performer. They additionally permit the examination of a few systems.

Pre grouting of linkage resistor and rock expansion

In underground construction ground water inflow and rock mass stability has been a major challenge. The tunnels which were constructed below ground water table are oftenly used to expose the risk of ground water inflow. The protection of undergroundstructures against water ingress and rock mass failure is of paramount importance during construction as well as while operating the tunnels. Several risks related to these hydrogeological issues pose many challenges to engineers. Moreover, such practices were measured for leakage control and rock mass improvement which is being successfully implemented in many countries.

Control of groundwater leakage and rock mass stability has always been a challenging task for tunneling engineers. Slowing down of the tunnel advance rates, installation of support systems, durability of the lining systems and hindrance to safe operation of the tunnel are some of the key risks faced in most of tunneling projects due to water ingress and rock mass instability. These problems often lead to schedule delays and cost overruns.

Adaptive Decision Feedback Equalization

Data-intensive applications such as video streaming, cloud computing, and virtual presence devices require data to be transmitted among chips, modules, and chassis via serial copper channels at tens of giga-bit-per-second (Gbps). The data rate of these links is limited by inter-symbol interference (ISI) arising from channel impairment such as finite bandwidth, reflection, and crosstalk. Al-though low-loss channels and low-reflection vias/connectors are highly desirable, they are costly. 

Far-end channel equalization combats ISI by either amplifying the high-frequency components of received data symbols or removing post-cursors by subtracting estimated post-cursors from data symbols. The former is known as continuous-time linear equalization (CTLE) while the latter is termed nonlinear equalization. Since the effect of the imperfection of channels is entailed in data symbols received at the far end of the channels, post-equalization can be adjusted objectively to eliminate the effect of the impairments of the channels so as to achieve better channel equalization.

 

Retinal Exudate Detection using Novel Fuzzy Clustering Methods

At present there is an increased interest in Therapeutic image processing in most fields of engineering. Imaging modality provides detailed information about anatomy. It is also helpful in the finding of the disease and its progressive treatment. The Prime signs of Diabetic Retinopathy(DR) are Exudates which leads to severe vision loss in chronic condition. Exudates are the remnant of exuded blood and protein based particles from the damaged blood vessels of retina. Laser healing requires accurate location of exudates for faithful removal through Laser burns. Segmentation of fundoscope image will help the ophthalmologist in diagnosis, classification and to determine the severity. Multiple methods are designed and developed for Medical Image segmentation based on thresholding, Region Growing, Markov Random Model, Clustering, Deformable Model, Classifier, Neural Networks, Expectation Maximization and Support vector machines etc. Out of these the fuzzy clustering methods are less complex and are robust in operation. This paper aims in performance evaluation of Fuzzy C means clustering (FCM) algorithm, Kernel induced FCM (KFCM) and Spatial FCM (SFCM) algorithms are done.

  

Diabetes is a chronic condition which requires lifelong therapeutic care and edification of self-management by the patient to put offinitial complications and to lessen the threat of continuing problems. Beyond glycemic control, its care is quite complex as it poses the root cause of many issues.