Reliability and availability estimation of a photovoltaic system using Petri networks

Many photovoltaic (PV) systems are nowadays installed all around the world. However, the reliability and the availability estimation of photovoltaic systems have not been received great attention from researchers. Reliability and availability are important consideration in the life-cycle of such systems. This paper presents a methodology for estimating the reliability and the availability of a photovoltaic system using Petri networks. Each component - module, wires and inverter - is detailed in Petri networks and several laws are used in order to determine the reliability and system availability. The degradation function of each componenthas been taken into account. Results show that Petri networks simplify the reliability and availability modeling and analysis

Fluid thrust bearing reliability analysis using finite element modelling and response surface method

This paper presents a methodology for the failure probability evaluation of a thrust fluid bearing which plays a significant role in stability of machines rotors, mechatronic systems and high precision metrology systems. The static and dynamic behaviour of a fluid bearing depends on several parameters such as external load, the dimensions of the bearing, the supply pressure, the manufacturing capability and fluid properties. In this paper, the analysis of the fluid bearing characteristics is carried out using the finite element method (FEM). Stochastic response surface methodology (SRSM) is used for the approximation of the performance function of a bearing and the reliability is assessed by Monte Carlo simulation (MCS) and first order reliability method (FORM)

EVALUATION OF GENETIC DIFFERENCES ON IMMUNOLOGICAL RESPONSE IN TWO NATIVE CHICKEN STRAINS FED ON DIFFERENT NATURAL AND ORGANIC ACID SUPPLEMENTATION

The main objective of this study was to investigate the effect of the genetic differences in immunological response by use the natural growth promoters in diets offered to local chicken strains (GoldenMontazah (GM) and Bandra (B)). The present study was carried out in Seds Poultry Breeding Research Station, Animal Production Research Institute, Banysweif Governorate, through August to January (2016). A total of 240 chicks (120 hens of each strain) were used from 16 to 40 weeks of age. Birds were randomly distributed into six treatments. Each treatment had 20 (female) chicks (20X 6X 2) that were individually caged. The first treatment of each strain served as a control group and fed the formulated basal diet without any tested feed additives. The second treatment fed the basal diet with BioPlus® 2B, (400gm/ton) a commercial probiotic preparation (pro. (Bio)). The third treatment hens were fed the same basal diet with the addition of TechnoMos® (500gm/ton) a prebiotic type (pre. (Tech)).The fourth treatment fed the basal diet with Diamond V®(2.5kg/ton) a commercial prebiotic produced (pre. (Dia)). The fifth treatment fed the basal diet with FORMI® NDF (2kg/ton) (organic acid (FORMI)). The sixth treatment fed the basal diet with combination of (BioPlus® 2B, (400gm/ton) + TechnoMos® (500gm/ton) + FORMI® NDF (1kg/ton)) (combination (BTF)).  Data showed that, the Heterophils/Lymphocyte ratio percentage value was significantly higher in  Golden Montaza than Bandara. The highest value was found for organic acids (FORMI) group and the lowest value was found for probiotic (Bio Plus) group.  As for the antibody titer before vaccination the highest values were found for pre (Tech) group in comparison to pre (Dia) group. And there were no significant differences between the control group and all treated groups. Also, the higher values of antibody titer against Newcastle vaccine after vaccination were found in pre (Tech.), org ((FORMI), combination (Bio, Tech and FORMI) and control groups compare to values were found in pre (Dia) and pro (Bio) groups. As for the differences titer between before and after vaccination against Newcastle disease virus, there were no significant differences

Multi-sensor degradation data analysis

Multiple sensors are commonly used for degradation monitoring of critical components. The degradation indicators derived from these sensors are significantly different in terms of scale and interpretation. Since these indicators reflect the same degradation path but have different scales and noise, the fusion of the data corresponding to these indicators is important for the condition monitoring and accurate reliability estimation of the components. In this paper, we develop a unified degradation path that considers statistics-based degradation and physics-based degradation models. We also estimate the reliability of such components. Simulation results show that the unified degradation model approximates the actual degradation path effectively. Additionally, more accurate estimates of reliability are obtained when compared with individual degradation paths.Scopu

Unilateral Congenital Lenticular Pigmentation

Introduction: Release of pigments in the anterior chamber is frequently observed in pigment dispersion syndrome, an autosomal dominant disorder marked by bilateral pigment deposition on the anterior and possibly posterior lens capsule, zonules of the lens, trabecular meshwork, and corneal endothelium, in addition to radial, spoke-like transillumination defects in the mid peripheral iris [J Ayub Med Coll Abbottabad. 2017;29(3):412–414 and Optom Vis Sci. 1995;72(10):756–762]. Pigmentation of the anterior lens surface has also been associated with intraocular inflammation, pseudoexfoliation syndrome, siderosis, antipsychotic medication usage, and remnants of the tunica vasculosa lentis [Br J Ophthalmol. 1998;82(11):1344]. Case Presentation: A 23-year-old female presented to our eye clinic with chief complaint of mild blurring of vision in the right eye and inquired about refractive surgery. The patient denied any previous history of ocular inflammation, trauma, surgery, or use of topical or systemic medications. Slit-lamp examination of the right eye anterior segment was within normal limits except for the crystalline lens anterior capsular which showed confluent pigment deposits stellate in shape over the pupillary axis, whereas left eye examination was completely within normal limits. Ophthalmic examination of the posterior segment was normal in both eyes. Based on her previous ophthalmic history and slit-lamp examination of the right eye, a diagnosis of unilateral congenital lenticular pigmentation was made. Conclusion: Congenital lenticular pigmentation is a rare benign entity carrying no surgical indications with a relatively good visual response to optical correction. Recognition of this rare benign condition would add to the ophthalmologist’s differential of ocular pigmentation and avoid unnecessary concern and follow-up in more potentially progressive disorders such as pigmentary glaucoma

Incidence of intraocular lens exchange after cataract surgery

Intraocular lens (IOL) exchange after cataract surgery is unusual but may be associated with suboptimal visual outcome. The incidence of IOL exchange has not been consistently estimated. Such information is invaluable when counseling patients prior to cataract surgery. We examined the incidence of, and indications and risk factors for, IOL exchange after cataract surgery. We also assessed visual outcome of eyes that had an IOL exchange. A cohort design was used to estimate the incidence of IOL exchange and a case-control design to identify factors associated with it. All phacoemulsification surgeries with IOL (n = 17415 eyes) during 2010-2017 and those that had a subsequent IOL removal or replacement during the same time period were identified (n = 34 eyes). The incidence of IOL exchange was 2 per 1000 surgeries (95% confidence interval [CI] 1 to 3) over 8 years. Eyes that underwent subsequent IOL removal or replacement were compared with eyes that had cataract surgery only (n = 47) across demographic and clinical characteristics. In a binary logistic regression analysis, two factors were significantly associated with IOL exchange/removal: an adverse event during cataract surgery (adjusted odds ratio [aOR] 19.45; 95% CI 4.89-77.30, P \u3c 0.001) and a pre-existing ocular comorbidity (aOR 10.70; 95% CI 1.69-67.63, P = 0.021). The effect of gender was marginally significant (P = 0.077). Eyes that underwent IOL exchange or explantation were nearly two and a half times more likely to have a final best-corrected visual acuity of \u3c20/60 compared to those that had cataract surgery alone (adjusted RR 2.60 95% CI, 1.13-6.02; P = 0.025)

Assessing molecular and agronomic diversity in flax genotypes based on SCoT marker profiling, fibre yield contributing characters, and seed yield-related traits

Exploring genetic diversity is crucial for effective breeding strategies to enhance crop performance under diverse environmental conditions and accelerate selection with improved yield and adaptability to climate change. This study aimed to explore the genetic diversity of eleven flax genotypes (Linum usitatissimum L.) using Start Codon Targeted (SCoT) markers and evaluate their performance in fibre yield contributing characters and seed yield-related traits in two field trials during 2021-2022 and 2022-2023 seasons. SCoT markers revealed varying degrees of polymorphism, with primers SCoT-1, SCoT-24, and SCoT-27 displaying 100% polymorphism, indicating high genetic diversity among the genotypes. Genetic similarity analysis categorized the genotypes into four diverse groups. The agronomic performance indicated that ‘S.620’, ‘Sakha 3’, and ‘S.651’ excelled in straw yield and associated traits such as technical length, plant height, fibre percentage, total fibre yield, fibre length, and straw yield, while ‘Sakha 5’ and ‘S.945’ showed the lowest. On the other hand, ‘Sakha 5’ followed by ‘S.933/15/2’ and ‘Sakha 6' were the top performers for seed yield and related characteristics, including fruiting zone length, number of capsules per plant, seed index, seed yield, oil percentage, and seed and oil yields, while ‘IV2’ exhibited the lowest values. Hierarchical clustering divided the genotypes into distinct clusters based on straw and seed performance. Moreover, the principal component analysis highlighted a clear separation between genotypes excelling in straw and seed traits, with strong associations among related characters. These findings provide valuable insights for breeding programs to improve flax fibre and seed production

Fifteen Genetic Loci Associated with the Electrocardiographic P Wave

The P wave on an ECG is a measure of atrial electric function, and its characteristics may serve as predictors for atrial arrhythmias. Increased mean P-wave duration and P-wave terminal force traditionally have been used as markers for left atrial enlargement, and both have been associated with increased risk of atrial fibrillation. Here, we explore the genetic basis of P-wave morphology through meta-analysis of genome-wide association study results for P-wave duration and P-wave terminal force from 12 cohort studies. Methods and Results - We included 44 456 individuals, of which 6778 (16%) were of African ancestry. Genotyping, imputation, and genome-wide association study were performed at each study site. Summary-level results were meta-analyzed centrally using inverse-variance weighting. In meta-analyses of P-wave duration, we identified 6 significant (P<5×10-8) novel loci and replicated a prior association with SCN10A. We identified 3 loci at SCN5A, TBX5, and CAV1/CAV2 that were jointly associated with the PR interval, PR segment, and P-wave duration. We identified 6 novel loci in meta-analysis of P-wave terminal force. Four of the identified genetic loci were significantly associated with gene expression in 329 left atrial samples. Finally, we observed that some of the loci associated with the P wave were linked to overall atrial conduction, whereas others identified distinct phases of atrial conduction. Conclusions - We have identified 6 novel genetic loci associated with P-wave duration and 6 novel loci associated with P-wave terminal force. Future studies of these loci may aid in identifying new targets for drugs that may modify atrial conduction or treat atrial arrhythmias

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population