Transformer Diagnosis Using UV-Spectrophotometer

A power transformer is most significant and extremely important element in the power utility industry. Transformers are key-stone in transmission and distribution system. The failure of power transformer causes the interruption of power supply, huge financial loss. Failure coming without warning is responsible for large economic losses and unscheduled outage. In the absence of transformers components monitoring and diagnostics, the failure risk always remain high. The System abnormalities such as over loading, frequent switching, sever weather condition and poor maintains normally contribute to accelerated aging. The lack of proper monitoring and diagnostics leads to high risk of failure. Diagnostics and proper monitoring plays key role in the life expectancy of proper transformer. Mineral oil in transformer is the inseparable component of the dielectric insulation system. In this paper a new diagnostic technique for power transformer diagnostics known as uv spectrophotometry for transformer oil analysis has been discussed. This paper presents basic information about uv spectrophotometer, sampling and testing of transformer oil. Based on the spectrophotometer results and their subsequent analysis condition of transformer oil can be predicte

Impact of persisting amblyopia on socio–economic, health and well–being outcomes in adult life: findings from the UK Biobank study

Objectives: This study aimed to investigate associations between persisting amblyopia into adulthood and its “real-life” impacts and inform the current debate about the value of childhood vision screening programs. Methods: Associations between persisting amblyopia and diverse socioeconomic, health, and well-being outcomes were investigated in multivariable-adjusted (sex, age, ethnicity, deprivation) regression models, with 126 400 participants (aged 40-70 years) of the UK Biobank with complete ophthalmic data. Analysis by age group (cohort 1, 60-70 years; cohort 2, 50-59 years; cohort 3, 40-49 years) assessed temporal trends. Results: Of 3395 (3%) participants with confirmed amblyopia, overall 77% (2627) had persisting amblyopia, declining from 78% in cohort 1 to 73% in cohort 3. The odds of persisting amblyopia were 5.91 (5.24-6.66) and 2.49 (2.21-2.81) times greater in cohort 1 and cohort 2, respectively, than cohort 3. The odds were also higher for more socioeconomically deprived groups and for white ethnicity. Reduced participation in sport, adverse general and mental health, and well-being were all independently associated with persisting amblyopia, with the strongest associations in the youngest cohorts. Associations with lower educational attainment and economic outcomes were only evident in the oldest cohort. Conclusions: There has been a decline in the overall frequency of persisting amblyopia since the introduction of universal child vision screening in the United Kingdom. Nevertheless, most adults treated for amblyopia in childhood have persisting vision deficits. There was no evidence that persisting amblyopia has vision-mediated effects on educational, employment-related, or economic outcomes. The observed adverse outcomes were largely those not directly mediated by vision. Patients undergoing treatment should be counseled about long-term outcomes

Effect of delayed icing on the quality of tiger shrimp (Penaeus monodon Fab.)

Effect of delayed icing on the quality of Penaeus monodon iced after three hours of harvest was studied in plastic and bamboo baskets. After harvest of three hours at ambient temperature (28°-32°C), ice was added to the shrimp at a ratio of 1:1 (shrimp:ice) and stored for 21 hours in both the baskets. Quality evaluation was carried out through visual assessment, biochemical analysis and microbial analysis for 24 hours. The organoleptic evaluation and scoring was done from the time of harvest treated as 0 hour and the average score was 10. At 9th hour after iced condition quality of shrimp was found reduced to the next stage (acceptable) with a score ranged from 8.4-6.5 in both baskets. This acceptable stage was observed throughout the experiment for bamboo basket whereas in the plastic basket the quality was reduced to a small extent with a score of 6.4 (moderately acceptable). Till the end point of the experiment the quality of shrimp was acceptable in respect to biochemical analysis. The microbial load was found log sub(10) 3.99±0.12 cfu/g to log sub(10) 4.33±0.21 cfu/g and log sub(10) 4.01 ±0.12 cfu/g to log sub(10) 4.83±0.19 cfu/g in the bamboo and plastic basket respectively. The importers or buyers suggests for immediate icing to maintain good quality but results of the present experiment suggest that the quality does not vary drastically for first three hours

Modelling the effect of behavior on the distribution of the jellyfish Mauve stinger (Pelagianoctiluca) in the Balearic Sea using an individual-based model

Jellyfish behavior and physiology significantly influence spatial distribution and aggregations in the marine environment. However, current models used to study these transport patterns have a limited incorporation of these physiological and behavioral variables. In this paper, the life cycle and movement of the mauve stinger, Pelagia noctiluca, is simulated from fertilized egg up to the adult stage using an individual-based model (IBM). Our model combines available knowledge on the mauve stinger with inputs of ocean currents and temperature from the CMEMS hydrodynamic model. Horizontal transport is solely governed by ocean currents, but vertical distribution is controlled by diel vertical migration, motility and stage of development. Particle agents are released along the submarine canyons in the Spanish Mediterranean waters during the spring reproduction period, to later disperse and develop through an interplay between physical and biological processes. When compared with a simpler model, that omits behavior and physiology, the biophysical model is able to qualitatively better predict stranding events in the Balearic Sea. Our results expose the potential for operational life stage and distribution modelling of jellyfish

Casimir Force at a Knife's Edge

The Casimir force has been computed exactly for only a few simple geometries, such as infinite plates, cylinders, and spheres. We show that a parabolic cylinder, for which analytic solutions to the Helmholtz equation are available, is another case where such a calculation is possible. We compute the interaction energy of a parabolic cylinder and an infinite plate (both perfect mirrors), as a function of their separation and inclination, $H$ and $\theta$, and the cylinder's parabolic radius $R$. As $H/R\to 0$, the proximity force approximation becomes exact. The opposite limit of $R/H\to 0$ corresponds to a semi-infinite plate, where the effects of edge and inclination can be probed.Comment: 5 pages, 3 figures, uses RevTeX; v2: expanded conclusions; v3: fixed missing factor in Eq. (3) and incorrect diagram label (no changes to results); v4: fix similar factor in Eq. (16) (again no changes to results

Design Optimization of High-Frequency Power Transformer by Genetic Algorithm and Simulated Annealing

This paper highlights the transformer design optimization problem. The objective of transformer design optimization problem requires minimizing the total mass (or cost) of the core and wire material by satisfying constraints imposed by international standards and transformer user specification. The constraints include appropriate limits on efficiency, voltage regulation, temperature rise, no-load current and winding fill factor. The design optimizations seek a constrained minimum mass (or cost) solution by optimally setting the transformer geometry parameters and require magnetic properties. This paper shows the above design problems can be formulated in genetic algorithm(GA) and simulated annealing (SA) format. The importance of the GA and SA format stems for two main features. First it provides efficient and reliable solution for the design optimization problem with several variables. Second, it guaranteed that the obtained solution is global optimum. This paper includes a demonstration of the application of the GP technique to transformer design.Key word—Optimization, Power Transformer, Genetic Algorithm (GA), Simulated Annealing Technique (SA)DOI:http://dx.doi.org/10.11591/ijece.v1i2.8

UK & Ireland observational study of outcomes following congenital / infantile cataract surgery: IoLunder2 five year follow up

PURPOSE: To investigate outcomes following cataract surgery with and without primary intraocular lens implantation in children aged under 2 years with congenital or infantile cataract. METHODS: A bi-national prospective longitudinal cohort study undertaken through a collaborative research network, with case ascertainment through active surveillance, and standardised data collection on children who underwent cataract surgery with and without IoL implantation between Jan ‘09 and Dec ’10. Multivariable multilevel regression modelling was undertaken to interrogate the association between IoL implantation and outcomes of interest. RESULTS: 256 children were recruited into the study following informed parental consent. For 242 (95%) children, 5 year post–operative follow up data were available. Overall, median age at surgery was 7 weeks (IQR 5 weeks-7 months). Significant ocular co-morbidity (horizontal corneal diameter<10mm, axial length<16mm, complex persistent fetal vasculature, other structural anomaly) was present in 42% of BCC eyes, 39% of UCC eyes. Primary IoL implantation was undertaken in 58/149 children with bilateral congenital/infantile cataract (BCC) and 45/93 with unilateral disease (UCC). Children who underwent IoL implantation were older at surgery, less likely to have an ocular comorbidity, and less likely to live in relative socioeconomic deprivation. At 5 years following surgery, median acuity in eyes of children with BCC was 0.5 logMAR (interquartile range 0.2-0.9), and with both eyes open 0.38. Median acuity in operated eyes of children with UCC was 0.8 logMAR (IQR 0.4-1.5). Secondary glaucoma had been diagnosed in 24% of BCC children (13% of eyes), and 12% of children with UCC. Following adjustment for age at surgery and presence of co-existent anomalies, IoLs were not associated with better visual outcome, and did not reduce odds of secondary glaucoma. CONCLUSIONS: Based on the findings that IoLs do not confer visual benefit or protective effect against glaucoma (as previously postulated), and previous findings of a higher risk of re-operation, routine use of IoLs in children under 2 years is not advocated. IoLunder2 is also able to provide data on the associations of visual outcomes and glaucoma risk with age at surgery, peri-operative management and post-operative rehabilitation, in order to inform policy and practice

Congenital cataract associated with persistent fetal vasculature: findings from IoLunder2

PURPOSE: To describe the frequency, characteristics, and treatment outcome of persistent fetal vasculature (PFV) in children undergoing surgery for congenital and infantile cataract in the first 2 years of life. PATIENTS AND METHODS: Observational population-based cohort study with case identification through active surveillance and standardised data collection via a national clinical network, the British Isles Congenital Cataract Interest Group (BCCIG). RESULTS: The IoLunder2 cohort comprises 246 children undergoing surgery for bilateral and unilateral congenital and infantile cataract in the first 2 years of life. A total of 58/246 (24%) children had PFV (%): overall, 46/95 (46%) with unilateral cataract, and 12/141 (8%) with bilateral disease. Anterior segment vascular remnants were more common in bilateral than unilateral disease (75 vs 11%, P=0.01). At 1 year after surgery, 20% of children with bilateral PFV and 24% with unilateral had achieved normal vision for age within the operated eye. The prevalence of post-operative glaucoma was 9% (of children with bilateral disease) and 4% (unilateral). CONCLUSION: PFV is significantly more common than previously reported, and outcomes are comparable to that for congenital and infantile cataract overall