Multimodal Tuning of an Axisymmetric Resonator

This paper reports an approach for the simultaneous elimination of the modal frequency differences within two pairs of modes in an axisymmetric resonator. Fabricated devices exhibit frequency detuning, which can be eliminated by strategically mass loading the resonator. Each pair of modes responds to the mass loading differently so models are developed to predict the postloading frequency differences. The models are incorporated into a search procedure to select deposition sites that simultaneously reduce the modal frequency difference within each pair. The proposed approach is successfully implemented on a resonator whose modal frequency differences are reduced below 200 mHz from an initial frequency difference of 23.5 Hz for a pair of modes at 13.8 kHz, and a 2.4 Hz difference for another pair of modes at 24.3 kHz

Heat Exchanger Fouling in Phosphoric Acid Evaporators - Evaluation of Field Data -

Multistage evaporators are frequently used in phosphoric acid plants to increase the concentration of dilute phosphoric acid to 52-55 wt% P2O5. The concentrated phosphoric acid solution is supersaturated with respect to calcium sulfate. As a result, part of the calcium sulfate in the liquor deposits on the heat exchanger tube walls. Since the thermal conductivity of these scales is very low, thin deposits can create a significant resistance to heat transfer. Therefore, regular cleaning of heat exchangers is required, frequently at less than biweekly intervals. As the major costs in modern phosphoric acid plants are the cost of energy, a thorough understanding of the fouling kinetics and of the effects of various operational parameters on the behavior of calcium sulfate is required to improve operation and design of the shell and tube heat exchangers, which are extensively used. In this investigation, a large number of heat exchanger data were collected from shell and tube heat exchangers of the phosphoric acid plant of the Razi Petrochemical Complex (Iran) and the fouling deposits were analyzed with respect to appearance and composition. The overall heat transfer coefficients and fouling resistances were evaluated at different times and a kinetic model for the crystallization fouling was developed. It is shown that the crystallization rate constant obeys an Arrhenius relationship with activation energy of 57 kJ/mol. The predictions of the suggested model are in good agreement with the plant data

Effects of mindful parenting training on clinical symptoms in children with attention deficit hyperactivity disorder and parenting stress: Randomized controlled trial

Abstract Background: Children with attention deficit hyperactivity disorder (ADHD) are at risk of impairment in multiple domains. This study aimed to investigate the effectiveness of mindful parenting training in reducing clinical symptoms in children with ADHD and parenting stress of their parents. Methods: This randomized clinical trial was conducted on 2 groups (experimental and control) in 3 phases (pretest, posttest, and 8 weeks’ follow-up). Sixty children with ADHD, who had been referred by the child psychiatrist in the Iranian city of Kashan in the second half of the year 2016, were selected along with their mothers. The mothers were assigned to one of the 2 groups via permuted blocked randomization. The mothers completed the parenting stress index–short form (PSI–SF 36) and the Swanson, Nolan, and Pelham Parent and Teacher rating scale (SNAP-IV). All the children in both groups received pharmacotherapy with either risperidone or Ritalin. The intervention group received 8 sessions (1 session each week, each session lasting 90 minutes) of mindful parenting training based on the Kabat-Zinn protocol. The data were analyzed using SPSS, version 20, via the t test, χ2 test, repeated measures analysis of variance, and nonparametric Friedman test. Results: This study showed a reduction in parenting stress, negative parent-child interactions, and children’s problematic characteristics in the mindful parenting training group compared with the control group in the posttest and follow-up. Our results also demonstrated a significant improvement in ADHD symptoms in the experimental group by comparison with the control group in the posttest and follow-up. Conclusion: Mindful parenting training was effective in reducing parenting stress and ADHD symptoms in our intervention group. Keywords ● Mindfulness ● Attention deficit disorder with hyperactivity ● Parenting ● Stress ● Physiologica

Drosophila local search emerges from iterative odometry of consecutive run lengths

The ability to keep track of one's location in space is a critical behavior for animals navigating to and from a salient location, but its computational basis remains unknown. Here, we tracked flies in a ring-shaped channel as they executed bouts of search, triggered by optogenetic activation of sugar receptors. Flies centered their back-and-forth local search excursions near fictive food locations by closely matching the length of consecutive runs. We tested a set of agent-based models that incorporate iterative odometry to store and retrieve the distance walked between consecutive events, such as reversals in walking direction. In contrast to memoryless models such as Levy flight, simulations employing reversal-to-reversal integration recapitulated flies' centered search behavior, even during epochs when the food stimulus was withheld or in experiments with multiple food sites. However, experiments in which flies reinitiated local search after circumnavigating the arena suggest that flies can also integrate azimuthal heading to perform path integration. Together, this work provides a concrete theoretical framework and experimental system to advance investigations of the neural basis of path integration

New insight into the informal patients' payments on the evidence of literature: A systematic review study

Background: Nowadays, a growing literature reveals how patients use informal payments to seek either better treatment or additional services, but little systematic review has been accomplished for synthesizing the main factors. The purpose of this study was to analyze the content of literatures to demonstrate the factors for informal patient payments. Methods: In this systematic review study, PubMed, Web of Science, Wiley Online Library, Science Direct, Ovid, Scopus, and Iranian databases were investigated without time limitation for eligible English and Persian studies. Achieved data were analyzed using content analysis approach and MAXQDA 10 software. Results: Themes related to informal payments in external context of health system were demographic features of health service consumers, patient's personality features and social & cultural backgrounds of the community. Health system challenges' themes were about stewardship weakness, and sustainable financing and social protection weakness. These were followed by human resources' organizational behavior challenges, drugs, medical products, and services delivery provision process challenges and finally change management weakness for reducing and dealing with IPs. Conclusion: It appears that improving the quality of health care services and accurate monitoring of delivery processes, along with performing some strategies for regulating payroll and medical tariffs, strict rules and regulations and improving health staff motivation, would be effective ways against informal payments. Improving the health insurance contribution, promoting transparency & accountability in health system especially in financing, identify precise control mechanism, using empower patient/public related approach, modifying community perception, reinforcing social resistance to unofficial payments and rebuilt lost social capital in health care are some of the other recommendations in this field. To practice these strategies, a comprehensive and systemic vision and approach is needed, however, the key point is that before applying any strategy the impact of this strategy on access, efficiency, equity, and other health systems' goals and policies should be investigated due to the consideration. © 2020 The Author(s)

Mass and Shape Determination of Optically Levitated Nanoparticles

When introducing a nanoparticle into an optical trap, its mass and shape are not immediately apparent. We combine a charge-based mass measurement with a shape determination method based on light scattering and an analysis of the damping rate anisotropy, all on the same set of silica nanoparticles, trapped using optical tweezers in vacuum. These methods have previously only been used separately, and the mass determination method has not been applied to asymmetric particles before. We demonstrate that the combination of these classification techniques is required to distinguish particles with similar mass but different shape, and vice versa. The ability to identify these parameters is a key step for a range of experiments on precision measurements and sensing using optically levitated nanoparticles

Multimodal Tuning of an Axisymmetric Resonator

This paper reports an approach for the simultaneous elimination of the modal frequency differences within two pairs of modes in an axisymmetric resonator. Fabricated devices exhibit frequency detuning, which can be eliminated by strategically mass loading the resonator. Each pair of modes responds to the mass loading differently so models are developed to predict the postloading frequency differences. The models are incorporated into a search procedure to select deposition sites that simultaneously reduce the modal frequency difference within each pair. The proposed approach is successfully implemented on a resonator whose modal frequency differences are reduced below 200 mHz from an initial frequency difference of 23.5 Hz for a pair of modes at 13.8 kHz, and a 2.4 Hz difference for another pair of modes at 24.3 kHz

Phenotypic and genetic diversity of motile aeromonads isolated from diseased fish and fish farms

Summary Samples from the kidney of 100 diseased fish with signs of haemorrhagic septicemia and 50 samples from outlet water of fish farms were taken aseptically and cultured. In the laboratory, 75 colonies of gram-negative bacteria were biochemically diagnosed as motile aeromonads in our Bacteriology Laboratory Unit using API 20E rapid identification system. The genotype identification using specific primers for 16S rDNA by PCR and direct sequencing of 28 Iranian motile aeromonads isolates were as follow: in diseased fish, Aeromonas hydrophila (3 isolates, 15%), A. veronii bv. sobria (8 isolates, 40%), A. bestiarum/piscicola (5 isolates, 25%), A. media (3 isolates, 15%), A. jandaei (1 isolate, 5%), A. aquariorum (0 isolate, 0%) and in water, Aeromonas hydrophila (0 isolate, 0%), A. veronii bv. sobria (6 isolates, 75%), A. bestiarum/piscicola (0 isolate, 0%), A. media (1 isolate, 12.5%), A. jandaei (0 isolate, 0%) and A. aquariorum (1 isolate, 12.5%). Results of this study suggest that the incidence of motile aeromonads septicemia due to A. veronii bv. sobria is the most prevalent motile aeromonads. Nucleotide polymorphisms on the sequencing results of the 16S rDNA were detected as noticeable inter and intra-specific variation within the population of different aeromonads isolates. In total, 10-20 variant nucleotide positions in this region were observed among Aeromonas spp

Evaluation of Antioxidant and Antimicrobial Properties of Nanoemulsion of Citrus paradisi Essential Oil Against Pathogenic Microorganisms: In Vitro Study

Introduction Oxidation reactions and microorganisms’ activity are considered as the most important factors affecting the quality of food products. Recently, in the light of the inefficiency of some chemical preservatives against microorganisms and the presence of toxic residues in food products, the use of natural antimicrobials and antioxidants has been increased. Natural antimicrobial compounds have the potential to control microbial contamination and reduce the use of antibiotics. Plant essential oils are natural compounds with the potential to be used as active ingredients in the food, pharmaceutical, and cosmetic industries. Various studies have shown that essential oils have antifungal, antibacterial, antiviral, and antioxidant activity. The essential oils are considered as superb preservatives with various biological functions. Essential oils are generally recognized as safe product (GRAS) which can be used as an alternative to synthetic additives. Grapefruit (Citrus paradisi) peel and fruit contain active ingredients such as acids, flavonoids, vitamin C, and potassium, and its essential oil is composed of terpenic hydrocarbons, such as citral, limonene, citronelal, and geraniol. Although plant essential oils have antimicrobial and antioxidant properties, one of the main problems of these natural compounds is their high volatility and instability. In this context, nanoemulsion formulations are frequently used to increase the stability and efficiency of these biologically active compounds. This study is therefore aimed to nanoemulsifying the grapefruit essential oil and evaluate its antioxidant and antimicrobial properties.   Materials and Methods β-carotene, linoleic acid, ABTS (2,2’-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), and DPPH (2,2-diphenly-1-picrylhydrazyl) were purchased from Sigma-Aldrich Co. (USA). Mueller Hinton Broth (MHB) and Mueller Hinton Agar (MHA) were supplied from Merck Co. (Darmstadt, Germany). Grapefruit peel was dried at ambient temperature and then powdered. The obtained powder was then transferred to a Clevenger device containing 750 ml of distilled water to perform the distillation extraction (3 h). The resulting grapefruit essential oil was stored at 4 °C until use. Grapefruit essential oil was prepared using the hydrodistillation method, and then nanoemulsified. The antioxidant activity of the nanoemulsified essential oil was investigated by DPPH and ABTS  radical scavenging activity and beta-carotene/linoleic bleaching test. The nanoemulsified essential oil or methanolic (control) was mixed with DPPH solution and the mixture was then stored at ambient temperature for 30 min, in a dark place. The control sample was prepared by methanol. The absorbance of the samples was measured at 517 nm. To determine the ABTS-RS activity, the nanoemulsified essential oil was briefly charged with methanolic ABTS radical cation solution and the resulting mixture was left at room temperature for 30 min. Afterward, the absorbance was read at 734 nm. A spectrophotometric method was applied to monitor β-carotene/linoleate solution bleaching in the presence of the nanoemulsified essential oil. To do this, the absorbance of the solution was recorded at 490 nm after 120 min against the control sample at time zero and after 120 min. Antibacterial effect of the grapefruit essential oil nanoemulsion was also evaluated against Escherichia coli ATCC 25922, Salmonella typhi ATCC 6539, Pseudomonas aeruginosa ATCC 27853, Listeria innocua ATCC 33090, Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Bacillus subtilis ATCC 23857, Streptococcus pyogenes ATCC 19615, and Staphylococcus epidermidis ATCC 12228, based on disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration.   Results and Discussions The results showed that the nanoemulsion of grapefruit essential oil had a remarkable antioxidant effect of 42.27 mg/ml, 33.27 mg/ml and 54.54%, respectively, based on DPPH, ABTS, and beta-carotene-linoleic acid bleaching tests. According to disk diffusion agar and well diffusion agar results, the lowest inhibition zone was related to E. coli and the highest inhibition zone was observed in L. innocua. The minimum inhibitory concentration for L. innocua and S. aureus (the most sensitive bacteria) was 25 mg/ml, and E. coli, S. typhi, and P. aeruginosa had the highest inhibitory concentration. Also, the lowest bactericidal concentration was related to L. innocua and S. aureus bacteria and the highest concentration was observed for E. coli, S. typhi and P. aeruginosa. The nanoemulsified essential oil generally exhibited greater antibacterial activity against Gram-positive species. This could be mainly due to the difference in the cell wall composition of Gram-positive bacteria in comparison to Gram-negative; Gram-positive bacteria have a thicker mucopeptide layer in their cell wall, while Gram-negative bacteria have only a thin layer of mucopeptide and the wall structure is mainly composed of lipoprotein and lipopolysaccharide, thereby leading to a higher resistant to antibacterial agents According to the results, grapefruit essential oil nanoemulsion can be used as a natural antioxidant and antimicrobial agent to control oxidation reactions and the growth of spoilage and pathogenic microorganisms