Neuro-Fuzzy Control Technique in Hybrid Power Filter for Power Quality Improvement in a Three-Phase Three-Wire Power System

Hybrid power filters have proven to play a vital role in harmonic elimination as well as reactive power compensation in power systems concentrated with highly nonlinear loads which has in the last decade increased due to industrial automation and use of power converters based systems in industries and our homes. This paper presents an approach to hybrid shunt active filter for compensating voltage/current harmonics in a three phase three wire system. It is a combination of a shunt C-type high-pass filter in parallel with an active filter controlled by a Neuro-fuzzy controller. The C-type will help to reduce component rating for active filter and suppress the overall filter resonance while active filter compensate for the low order harmonics.  A three phase converter supplying highly inductive load has been chosen as a typical nonlinear load for which a shunt hybrid power filter comprising of a shunt C-type high pass passive  filter and a shunt active filter is employed to improve the power quality at the source end. Extensive simulation has been carried out and results obtained from the proposed approach gives comparatively better total harmonic distortion (THD) value. Key words: Power Quality, Shunt Power Filter, C-type filter, Neuro-Fuzzy Controller, Total Harmonic distortion (THD)

Concurrent Sessions B: Fish Physiology and Fishway Passage Success - Olfactory Gene Regulation in a Regulated River: Understanding the Effects of Altered Flow Patterns on Sockeye Salmon Homing

Pacific salmon use olfactory cues to locate their spawning grounds. Past homing research has explored various aspects of the olfactory system, such as the imprinting process, but the mechanisms through which olfaction drives homing remain largely unknown. Genomics studies provide a novel approach to homing research, allowing us to investigate how olfaction and alterations to flow regimes that result from hydroelectric development mediate homing from a molecular level. Olfactory receptors (ORs) located in the olfactory epithelia detect odorants in the external environment. These receptors initiate the olfactory process, and expression of OR genes therefore strongly influences route selection during the spawning migration. We examined the expression of OR genes in a population of early summer Fraser River sockeye at the site of a hydroelectric dam. Due to diversions caused by the dam, chemical cues originating from the natal tributary are diluted by water that enters the system from a different watershed. We held sockeye in the river containing their home stream water and in the river that originates from the different watershed. We then used quantitative PCR to determine whether the absence of natal chemical cues alters olfactory gene expression. In addition, we analyzed olfactory gene expression of sockeye exposed to an artificial stressor event, to determine whether stressful events such as fishway passage or blocked waterways affect olfactory gene expression

Molecular epidemiology of human rhinovirus infections in Kilifi, coastal Kenya

This study reports pediatric surveillance over 3 years for human rhinovirus (HRV) at the District Hospital of Kilifi, coastal Kenya. Nasopharyngeal samples were collected from children presenting at outpatient clinic with no signs of acute respiratory infection, or with signs of upper respiratory tract infection, and from children admitted to the hospital with lower respiratory tract infection. Samples were screened by real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) and classified further to species by nucleotide sequencing of the VP4/VP2 junction. Of 441 HRV positives by real-time RT-PCR, 332 were classified to species, with 47% (155) being HRV-A, 5% (18) HRV-B, and 48% (159) HRV-C. There was no clear seasonal pattern of occurrence for any species. The species were present in similar proportions in the inpatient and outpatient sample sets, and no significant association between species distribution and the severity of lower respiratory tract infection in the inpatients could be determined. HRV sequence analysis revealed multiple but separate clusters in circulation particularly for HRV-A and HRV-C. Most HRV-C clusters were distinct from reference sequences downloaded from GenBank. In contrast, most HRV-A and HRV-B sequences clustered with either known serotypes or strains from elsewhere within Africa and other regions of the world. This first molecular epidemiological study of HRV in the region defines species distribution in accord with reports from elsewhere in the world, shows considerable strain diversity and does not identify an association between any species and disease severity

Design and operation of a prototype interaction point beam collision feedback system for the International Linear Collider

A high-resolution, intratrain position feedback system has been developed to achieve and maintain collisions at the proposed future electron-positron International Linear Collider (ILC). A prototype has been commissioned and tested with a beam in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization in Japan. It consists of a stripline beam position monitor (BPM) with analogue signal-processing electronics, a custom digital board to perform the feedback calculation, and a stripline kicker driven by a high-current amplifier. The closed-loop feedback latency is 148 ns. For a three-bunch train with 154 ns bunch spacing, the feedback system has been used to stabilize the third bunch to 450 nm. The kicker response is linear, and the feedback performance is maintained, over a correction range of over $\pm$60 {\mu}m. The propagation of the correction has been confirmed by using an independent stripline BPM located downstream of the feedback system. The system has been demonstrated to meet the BPM resolution, beam kick, and latency requirements for the ILC

A sub-micron resolution, bunch-by-bunch beam trajectory feedback system and its application to reducing wakefield effects in single-pass beamlines

A high-precision intra-bunch-train beam orbit feedback correction system has been developed and tested in the ATF2 beamline of the Accelerator Test Facility at the High Energy Accelerator Research Organization in Japan. The system uses the vertical position of the bunch measured at two beam position monitors (BPMs) to calculate a pair of kicks which are applied to the next bunch using two upstream kickers, thereby correcting both the vertical position and trajectory angle. Using trains of two electron bunches separated in time by 187.6~ns, the system was optimised so as to stabilize the beam offset at the feedback BPMs to better than 350~nm, yielding a local trajectory angle correction to within 250~nrad. The quality of the correction was verified using three downstream witness BPMs and the results were found to be in agreement with the predictions of a linear lattice model used to propagate the beam trajectory from the feedback region. This same model predicts a corrected beam jitter of c.~1~nm at the focal point of the accelerator. Measurements with a beam size monitor at this location demonstrate that reducing the trajectory jitter of the beam by a factor of 4 also reduces the increase in the measured beam size as a function of beam charge by a factor of c.~1.6.Comment: 16 pages, 10 figure

Evaluation of a measles vaccine campaign by oral-fluid surveys in a rural Kenyan district: interpretation of antibody prevalence data using mixture models

We evaluated the effectiveness of a measles vaccine campaign in rural Kenya, based on oral-fluid surveys and mixture-modelling analysis. Specimens were collected from 886 children aged 9 months to 14 years pre-campaign and from a comparison sample of 598 children aged 6 months post-campaign. Quantitative measles-specific antibody data were obtained by commercial kit. The estimated proportions of measles-specific antibody negative in children aged 0–4, 5–9 and 10–14 years were 51%, 42% and 27%, respectively, pre- campaign and 18%, 14% and 6%, respectively, post-campaign. We estimate a reduction in the proportion susceptible of 65–78%, with ~85% of the population recorded to have received vaccine. The proportion of ‘weak’ positive individuals rose from 35% pre-campaign to 54% post-campaign. Our results confirm the effectiveness of the campaign in reducing susceptibility to measles and demonstrate the potential of oral-fluid studies to monitor the impact of measles vaccination campaigns

Students’ Views on the Nature of Science in an Interdisciplinary First-Year Science Program: Content Analysis of a Weekly Reflection Activity

A primary aim of science education is to teach students how to interpret and engage with scientific information. To do so effectively requires an adequate understanding of the nature of science (NOS)—in other words, what science is and how it works. There is a long history of evidence to suggest that many undergraduate students struggle to properly understand NOS. While the specific factors contributing to misinformed views on NOS may be difficult to tease apart, the way in which students learn about science at the undergraduate level is a significant contributor. We implemented a reflection activity in a unique first-year program at a large Canadian university in order to promote student learning of NOS. Through the students’ reflections, we identified how certain pedagogical approaches, many of which deviate from traditional teaching methods used throughout undergraduate science education, can positively impact student comprehension of NOS. Our experiences support the use of reflective practices in promoting critical thinking and the development of more nuanced student views of NOS. Click here to read the corresponding ISSOTL blog post

Successes and Challenges in an Integrated Tuberculosis/HIV Clinic in a Rural, Resource-Limited Setting: Experiences from Kericho, Kenya

Objective. To describe TB/HIV clinic outcomes in a rural, Ministry of Health hospital. Design. Retrospective, secondary analyses. Descriptive statistics and logistic regression analyses evaluated baseline characteristics and outcomes. Results. Of 1,911 patients, 89.8% were adults aged 32.0 (±12.6) years with baseline CD4 = 243.3 (±271.0), 18.2% < 50 cells/mm3. Pulmonary (84.8%, (32.2% smear positive)) exceeded extrapulmonary TB (15.2%). Over 5 years, treatment success rose from 40.0% to 74.6%, lost to follow-up dropped from 36.0% to 12.5%, and deaths fell from 20.0% to 5.4%. For patients starting ART after TB treatment, those with CD4 ≥ 50 cells/mm3 were twice as likely to achieve treatment success (OR = 2.0, 95% CI = 1.3–3.1) compared to those with CD4 < 50 cells/mm3. Patients initiating ART at/after 2 months were twice as likely to achieve treatment success (OR = 2.0, 95% CI = 1.3–3.3). Yearly, odds of treatment success improved by 20% (OR = 1.2, 95% CI = 1.0–1.5). Conclusions. An integrated TB/HIV clinic with acceptable outcomes is a feasible goal in resource-limited settings