Application of Grey Wolf Optimizer Algorithm for Optimal Power Flow of Two-Terminal HVDC Transmission System

This paper applies a relatively new optimization method, the Grey Wolf Optimizer (GWO) algorithm for Optimal Power Flow (OPF) of twoterminal High Voltage Direct Current (HVDC) electrical power system. The OPF problem of pure AC power systems considers the minimization of total costs under equality and inequality constraints. Hence, the OPF problem of integrated AC-DC power systems is extended to incorporate HVDC links, while taking into consideration the power transfer control characteristics using a GWO algorithm. This algorithm is inspired by the hunting behavior and social leadership of grey wolves in nature. The proposed algorithm is applied to two different case-studies: the modified 5-bus and WSCC 9-bus test systems. The validity of the proposed algorithm is demonstrated by comparing the obtained results with those reported in literature using other optimization techniques. Analysis of the obtained results show that the proposed GWO algorithm is able to achieve shorter CPU time, as well as minimized total cost when compared with already existing optimization techniques. This conclusion proves the efficiency of the GWO algorithm

Women\u27s Long-Term Life Experience After Pregnancy Termination for Fetal Abnormality: Interpretive Phenomenological Study

Advances in prenatal screening and its availability for every woman have resulted in increasing the number of identified fetal abnormalities. The discovery of fetal abnormalities in the second trimester of pregnancy can force pregnant women into the dilemma of deciding the fate of their wanted pregnancies. A woman\u27s decision to terminate her pregnancy for a fetal abnormality in the second trimester is a very difficult and complicated decision. An interpretive phenomenological approach was used to gain an in-depth understanding of the long-term experiences of women who terminated their pregnancy for fetal abnormalities and reveal the meanings embedded in their experiences. Conversational in-depth interviews were conducted with ten women who had terminated their pregnancy more than five years previously. Thematic analysis guided by van Manen\u27s approach was used to uncover the meaning of the women\u27s experiences. Six themes were identified as characteristics of the women\u27s experiences over time: encountering the unexpected, making sense of the unexpected, facing the inevitable decision, living with the decision, feeling supported, and changing perspectives. The findings inform health care professionals about the complexities of these women\u27s\u27 experiences, perinatal grief and bereavement. It is hoped that health care professionals will evaluate their prenatal screening and counseling practices, and review their present models of care in light of these findings. Implications for practice and recommendations for future research are discussed

Molecular characterization of genetic diversity in some durum wheat (Triticum durum Desf.) in Palestine

Random amplified polymorphic DNA (RAPD) analysis was conducted to estimate the genetic diversity and relatedness among 10 wheat cultivars and landraces. Five out of 70 decamer random primers showed distinctly polymorphic bands when used to amplify genomic DNA. The primers yielded a total of 157 RAPD markers of which 150 were considered as polymorphic. Each primer produced 18 to 37 polymorphic bands with an average of 30 markers per primer. DNA fragments size ranged from 350 to 1910 bp. The mean similarity indices ranged from 0.05 to 0.68 with an average of 0.29. The unweighted pair group method with arithmetic mean (UPGMA) dendrogram based on Jaccard genetic similarity index, grouped the 10 landraces and cultivars into four main clusters. Despite the clustering of most landraces in the same cluster, high genetic variation was observed within cluster-I in which the genetic distance ranged from 73% between Hiteyah8 and White Dibeyah to 32% between Black Hiteyah and Yellow Hiteyah. The result of this study confirms high genetic diversity within these cultivars and landraces, and therefore, underlined the significant values of these cultivars and landraces as gene pool for durum wheat genetic improvement. Thus, RAPD offer a potentially simple, rapid and reliable method to evaluate genetic variation and relatedness among ten wheat landraces and cultivars.Keywords: Random amplified polymorphic DNA (RAPD), Triticum, genetic variatio

Passive smoking in the etiology of non-syndromic orofacial clefts:a systematic review and meta-analysis

Background Studies have found a consistent positive association between maternal smoking and nonsyndromic orofacial clefts (NSOFC). However, no comprehensive assessment of the association between NSOFC and passive smoking has been undertaken. This systematic review and meta-analysis explores the relationship between maternal passive smoking and NSOFC, and compares the associations between passive and active smoking. Methods and Findings Search strategy, inclusion / exclusion criteria, and data extraction from studies reporting maternal passive smoking and NSOFC was implemented without language restrictions. Risks of bias in the identified studies were assessed and this information was used in sensitivity analyses to explain heterogeneity. Meta-analysis and meta-regression of the extracted data were performed. Egger's test was used to test for small study effects. Fourteen eligible articles were identified. Maternal passive smoking exposure was associated with a twofold increase in risk of NSOFC (odds ratio: 2.11, 95% confidence interval: 1.54-2.89); this was apparent for both cleft lip with and without palate (OR: 2.05, 95% CI: 1.27-3.3) and cleft palate (OR: 2.11, 95% CI: 1.23-3.62). There was substantial heterogeneity between studies. In the studies that provided data enabling crude and adjusted odd ratios to be compared, adjustment for potential confounders attenuated the magnitude of association to about a 1.5-fold increase in risk. Conclusion Overall, maternal passive smoking exposure results in a 1.5 fold increase in risk of NSOFC, similar to the magnitude of risk reported for active smoking, but there is marked heterogeneity between studies. This heterogeneity is not explained by differences in the distribution of cleft types, adjustment for covariates, broad geographic region, or study bias/quality. This thorough meta-analysis provides further evidence to minimize exposure to environmental tobacco smoke in policy making fora and in health promotion initiatives.</p

Novi zakoni adaptivnog upravljanja referentnim modelom zasnovani na nekvadratnoj Ljapunovljevoj funkciji

In the design of model reference adaptive control (MRAC) schemes, adaptive laws have been developed based on Lyapunov stability theory. Over the past few decades, it has been a common practice to use Quadratic Lyapunov Functions (QLF). In contrast to such development, using a new Non-Quadratic Lyapunov Function (NQLF), this paper presents new adaptive laws for the MRAC. These new laws have the same advantage of assurance of stability of the overall system, as the earlier adaptive laws developed using the QLF. Over and above, they have an additional advantage of improved performance: in fact, the use of NQLF improved the system output error signal converging to zero. Finally, this paper also presents simulation results supporting the arguments.Za projektiranje sustava adaptivnog upravljanja referentnim modelom (MRAC) razvijeni su adaptivni zakoni koji se zasnivaju na Ljapunovljevoj teoriji stabilnosti. U zadnjih se nekoliko desetljeća uobičajeno koristi kvadratna Ljapunovljeva funkcija (QLF). Suprotno tome, u ovome se radu zakoni upravljanja referentnim modelom izvode na osnovi nove nekvadratne Ljapunovljeve funkcije (NQLF). Za izvedene je nove zakone upravljanja cjelokupni sustav stabilan, kao i kod prijašnjih zakona adaptivnog upravljanja kvadratnom Ljapunovljevom funkcijom. Povrh toga predloženim novim zakonima upravljanja NQLF funkcijom poboljšava se konvergencija izlaznog signala pogreške prema nuli. Na kraju su u radu predstavljeni rezultati simulacija koji podupiru navedene tvrdnje

Fault Location Effect on Short-Circuit Calculations of a TCVR Compensated Line in Algeria

This research work investigated the effect of fault location on short-circuit calculations for a high voltage transmission line equipped with a novel FACTS device, namely Thyristor Controlled Voltage Regulator (TCVR). This main function of this device was to control the voltage and active power of the line. The paper considered a study case for a 220 kV transmission line, in the Algerian transmission power network, which was subjected to a phase to earth fault in the presence of a fixed fault resistance. The paper presented theoretical analysis of the short-circuit calculations which was confirmed by the illustrated simulation results. Simulation results showed the impact of the fault location on the symmetrical current and voltage components of the line, and transmission line phase currents and voltages; before using TCVR and in the presence of TCVR for both cases of positive and negative TCVR controlled voltage

Novel Design of Emergency Exit Slide for High Rises

As the number of high rises buildings increases rabidly these days, residents safety and emergency escape solutions became crucial issue. Several hundreds of persons died or critically injured, each month, due to fire or emergency escape problems during fire or other emergency accidents in high rises around the world. This work aims to find a solution to this problem by proposing a novel design of emergency exit slide for high rises in order to reduce the number of victims during such emergencies. An emergency escaping volute slide or spiraled chute inside a tunnel including extendable accordion pleated tubing made of asbestos fabric, supported with vacuum-deposited aluminized materials padded on its inner side. A ring to its upper end, which made its base attachable with the top of the building supported with Artificial Spider Silk launchers to hold the slide during emergencies. Attachable to small slides from the escape openings of a building, the lower end of the tubing having a soft pad with low angle allowing a person sliding down the main slide can step up to assembly points on ground level, outside the building. The proposed technique resulted in enhanced results in comparison with previous techniques

Novi zakoni adaptivnog upravljanja referentnim modelom zasnovani na nekvadratnoj Ljapunovljevoj funkciji

In the design of model reference adaptive control (MRAC) schemes, adaptive laws have been developed based on Lyapunov stability theory. Over the past few decades, it has been a common practice to use Quadratic Lyapunov Functions (QLF). In contrast to such development, using a new Non-Quadratic Lyapunov Function (NQLF), this paper presents new adaptive laws for the MRAC. These new laws have the same advantage of assurance of stability of the overall system, as the earlier adaptive laws developed using the QLF. Over and above, they have an additional advantage of improved performance: in fact, the use of NQLF improved the system output error signal converging to zero. Finally, this paper also presents simulation results supporting the arguments.Za projektiranje sustava adaptivnog upravljanja referentnim modelom (MRAC) razvijeni su adaptivni zakoni koji se zasnivaju na Ljapunovljevoj teoriji stabilnosti. U zadnjih se nekoliko desetljeća uobičajeno koristi kvadratna Ljapunovljeva funkcija (QLF). Suprotno tome, u ovome se radu zakoni upravljanja referentnim modelom izvode na osnovi nove nekvadratne Ljapunovljeve funkcije (NQLF). Za izvedene je nove zakone upravljanja cjelokupni sustav stabilan, kao i kod prijašnjih zakona adaptivnog upravljanja kvadratnom Ljapunovljevom funkcijom. Povrh toga predloženim novim zakonima upravljanja NQLF funkcijom poboljšava se konvergencija izlaznog signala pogreške prema nuli. Na kraju su u radu predstavljeni rezultati simulacija koji podupiru navedene tvrdnje

Non-dominated sorting gravitational search algorithm for multi-objective optimization of power transformer design

Transformers are crucial components in power systems. Due to market globalization, power transformer manufacturers are facing an increasingly competitive environment that mandates the adoption of design strategies yielding better performance at lower mass and losses. Multi-objective Optimization Problems (MOPs) consist of several competing and incommensurable objective functions. Recently, as a search optimization technique inspired by nature, evolutionary algorithms have been broadly applied to solve MOPs. In this paper, a power Transformer Design (TD) methodology using Non-dominated Sorting Gravitational Search Algorithm (NSGSA) is proposed. Results are obtained and presented for NSGSA approach. The obtained results for the study case are compared with those results obtained when using other multi objective optimization algorithms which are Novel Gamma Differential Evolution (NGDE) Algorithm, Chaotic Multi-Objective Algorithm (CMOA), and Multi- Objective Harmony Search (MOHS) algorithm. From the analysis of the obtained results, it has been concluded that NSGSA algorithm provides the most optimum solution and the best results in terms of normalized arithmetic mean value of two objective functions using NSGSA to the TD optimization

Complementary remineralizing effect of self-assembling peptide (P11-4) with CPP-ACPF or fluoride : an in vitro study

Self-assembling peptide has been recently introduced to promote hard tissue regeneration for treating early non-cavitated carious lesions. This study investigates the efficacy of biomimetic self-assembling peptide (P11-4) on enamel remineralization combined with CPP-ACPF or fluoride. Artificial enamel lesions were created on buccal surface of 60 specimens and were randomly assigned to six groups according to the remineralizing agent: G1-(Control, artificial saliva), G2-(Fluoride varnish), G3-(CPP-ACPF varnish), G4-(Self-assembling peptide), G5-(Self-assembling peptide+fluoride varnish), G6-(Self-assembling peptide+CPP-ACPF varnish). All products were applied according to manufacturer?s instructions and specimens were stored in a daily renewed artificial saliva. Surface microhardness (SMH) and scanning electron microscope (SEM) were assessed at baseline, after demineralization, 1 week and 4 weeks storage. SMH values were analyzed using ANOVA and Tukey?s post-hoc test. The highest statistically significant SMH values were found in G6 followed by G5, G4, G2 and G3 while the lowest values were found in G1. No statistically significant difference was found between G5 and G6. Also, no statistically significant difference was found between G2 and G3. SEM showed that G4, G5, G6 resulted in more pronounced remineralization, reversing the demineralized enamel fish scale pattern compared to G2 and G3 after 1 week and 4 week remineralization. Complementary effect was obtained after combining self-assembling peptide with CPP-ACPF or fluoride showing the highest remineralizing potential early after 1 week and even after 4 weeks compared to when each agent used alone. Added benefits can be obtained through combining self-assembling peptide with other remineralzing agents allowing faster and enhanced regeneration of non-cavitated caries lesions