73 research outputs found

    Energy and Exergy Analyses

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    Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Nowadays, producing energy from solar thermal power plants based on organic Rankine cycles coupled with phase change material has attracted the attention of researchers. Obviously, in such solar plants, the physical properties of the utilized phase change material (PCM) play important roles in the amounts of generated power and the efficiencies of the plant. Therefore, to choose the best PCM, various factors must be taken into account. In addition, considering the physical properties of the candidate PCM, the issue of environmental sustainability should also be considered when making the selection. Deep eutectic solvents (DESs) are novel green solvents, which, in addition to having various favorable characteristics, are environmentally sustainable. Accordingly, in this work, the feasibility of using seven different deep eutectic solvents as the PCMs of solar thermal power plants with organic Rankine cycles was investigated. By applying exergy and energy analyses, the performances of each were compared to paraffin, which is a conventional PCM. According to the achieved results, most of the investigated “DES cycles” produce more power than the conventional cycle using paraffin as its PCM. Furthermore, lower amounts of the PCM are required when paraffin is replaced by a DES at the same operational conditions.publishersversionpublishe

    Energy conservation in absorption refrigeration cycles using DES as a new generation of green absorbents

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    ERC-2016-CoG 725,034 UID/QUI/50006/2019Deep eutectic solvents (DESs) are emerging green solvents with very unique characteristics. Their contribution to atmospheric pollution is negligible, and they can be "designed" for desired properties. In this study, the feasibility of applying DESs (Reline, Ethaline, or Glyceline) as absorbents in absorption refrigeration cycles was investigated. The sophisticated cubic-plus-association (CPA) equation of state, considering the strong intermolecular interactions of such complex systems, was used to estimate the thermodynamic properties. At a fixed set of base case operating conditions, the coefficients of performance were calculated to be 0.705, 0.713, and 0.716 for Reline/water, Ethaline/water, and Glyceline/water systems, respectively, while the corresponding mass flow rate ratios were 33.73, 11.53, and 16.06, respectively. Furthermore, the optimum operating conditions of each system were estimated. To verify the feasibility, results were compared to literature systems, including LiBr/water and various ionic liquid/water systems. The results indicate that DES/water working fluids have the potential to be used in such cycles. Since DESs have the characteristic to be tuned (designed) to desired properties, including their solvent power and their enthalpies of absorption, much further research needs to be done to propose new DESs with higher energy efficiencies.publishersversionpublishe

    Effect of Noise Pollution on the Hormonal and Semen Analysis Parameters in Industrial Workers of Bushehr, Iran

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    Objective: One of the concerns of health officials is noise pollution and in the realm of health, the problems of sterility and infertility resulting from noise pollution greatly attract the interest of experts nowadays. Noise is one of the harmful environmental factors and one of the most cacophonous of the unavoidable phenomena at home and workplace. Considering Bushehr is one of the cities with high infertility rates, we decided to study labor and industrial environments. Materials and Methods: Two groups of men volunteer workers, 27 members in each, who were constantly exposed to noisy 107- or 119-decibel environments, were studied together with one group of 27 workers living in quiet environments serving as the control. These people were referred to the Omid Khalij Fars Infertility Center in Bushehr where blood samples were taken and tested for adrenocorticotropic hormone (ACTH), cortisol, testosterone, prolactin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and thyroid hormones T3, T4, and Thyroid-stimulating hormone (TSH) and semen samples were taken and sent to the specialized laboratory of the Center. Results: Statistical studies showed that noise stress in the 119-decibel group significantly reduced the concentrations of the testosterone, prolactin, LH, and FSH hormones and of the thyroid hormones T3, T4, and TSH, and significantly increased the concentrations of the ACTH and cortisol hormones, compared to the control group. Moreover, semen analysis indicated major changes in semen parameters, especially under 119-decibel. Conclusion: Noise causes changes in hormones involved in the physiological process of fertility and in semen analysis parameters and, hence, has harmful effects on fertility

    Utilizing social virtual reality robot (V2R) for music education to children with high-functioning autism

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    Virtual Reality (VR) technology is a growing technology that has been used in various fields of psychology, education, and therapy. One group of potential users of VR are children with autism who need education and have poor social interactions; this technology could help them improve their social skills through real-world simulation. In this study, we evaluated the feasibility of conducting virtual music education programs with automatic assessment system for children with autism at treatment/research centers without the need to purchase a robot, resulting in the possibility of offering schedules on a larger scale and at a lower cost. Intervention sessions were conducted for five children with high-functioning autism ranging in age from 6 to 8 years old during 20 weeks which includes a baseline session, a pre-test, training sessions, a post-test, and a follow-up test. Each music education sessions involved teaching different notes and pieces of music according to the child’s cooperation, accuracy, and skill level utilizing virtual reality robots and virtual musical instruments. Actually, by analysis of psychological tests, and questionnaires conducted by a psychologist, we observe slight improvements in cognitive skills because of the ceiling effect. Nevertheless, the effectiveness of the proposed method was proved by conducting statistical analysis on the child’s performance data during the music education sessions which were obtained by using both video coding and the proposed automatic assessment system. Consequently, a general upward trend in the musical ability of participants was shown to occur in these sessions, which warrants future studies in this field

    Modeling Flame Propagation of Coal Char Particles in Heterogeneous Media

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    In the present research, combustion of a quiescent coal char particle cloud has been studied in the media with spatially discrete sources by means of numerical approach. A thermal model based on diffusion-controlled regime of coal char particles has been generated in order to estimate the characteristics of flame propagation in heterogeneous media. The model uses discrete heat sources to analyze dust combustion of particles with the diameter of 50 ÎŒm. Oxygen and Nitrogen have been considered as the main oxidizer and the inert gas, respectively. Flame propagation speed in various dust and oxygen concentrations has been studied. Flame speed as a function of particle size has been investigated and comparison between cases with and without consideration of radiation effect has been made. Furthermore, minimum ignition energy as a function of dust concentration for different particle sizes has been studied. Results show a reasonable compatibility with the existing experimental data

    Psychotherapy for Depression and Anxiety in Premenstrual Syndrome (PMS): A Systematic Review and Meta-Analysis

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    Background: There are several therapeutic methods for the premenstrual syndrome (PMS). Although psychotherapy has been introduced for women with PMS, no regular reconsiderations of these treatments are available. Aim of the present meta-analysis was conducted to evaluate the effect of psychotherapy interventions on the PMS. Materials and Methods:  The present systematic review and meta- analysis was conducted no restriction in date of publication until 13th March 2018 on electronic international databases of Medline (via PubMed), Scopus, Web of Science, and Cochrane Library as well as Iranian databases, such as Magiran, Medlib, and SID, using equivalent keywords in Persian. The quality of studies and data extraction was assessed by two authors. The standardized mean difference (SMD) measure was applied to calculate the main effect size. Results: Seven trials were included in systematic review. Depression level [SMD =-0.978;

    Inhibition of G-protein signalling in cardiac dysfunction of intellectual developmental disorder with cardiac arrhythmia (IDDCA) syndrome.

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    BACKGROUND: Pathogenic variants of GNB5 encoding the ÎČ5 subunit of the guanine nucleotide-binding protein cause IDDCA syndrome, an autosomal recessive neurodevelopmental disorder associated with cognitive disability and cardiac arrhythmia, particularly severe bradycardia. METHODS: We used echocardiography and telemetric ECG recordings to investigate consequences of Gnb5 loss in mouse. RESULTS: We delineated a key role of Gnb5 in heart sinus conduction and showed that Gnb5-inhibitory signalling is essential for parasympathetic control of heart rate (HR) and maintenance of the sympathovagal balance. Gnb5-/- mice were smaller and had a smaller heart than Gnb5+/+ and Gnb5+/- , but exhibited better cardiac function. Lower autonomic nervous system modulation through diminished parasympathetic control and greater sympathetic regulation resulted in a higher baseline HR in Gnb5-/- mice. In contrast, Gnb5-/- mice exhibited profound bradycardia on treatment with carbachol, while sympathetic modulation of the cardiac stimulation was not altered. Concordantly, transcriptome study pinpointed altered expression of genes involved in cardiac muscle contractility in atria and ventricles of knocked-out mice. Homozygous Gnb5 loss resulted in significantly higher frequencies of sinus arrhythmias. Moreover, we described 13 affected individuals, increasing the IDDCA cohort to 44 patients. CONCLUSIONS: Our data demonstrate that loss of negative regulation of the inhibitory G-protein signalling causes HR perturbations in Gnb5-/- mice, an effect mainly driven by impaired parasympathetic activity. We anticipate that unravelling the mechanism of Gnb5 signalling in the autonomic control of the heart will pave the way for future drug screening

    Clinical presentation and natural history of infantile-onset ascending spastic paralysis from three families with an ALS2 founder variant.

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    Biallelic mutations of the alsin Rho guanine nucleotide exchange factor (ALS2) gene cause a group of overlapping autosomal recessive neurodegenerative disorders including infantile-onset ascending hereditary spastic paralysis (IAHSP), juvenile primary lateral sclerosis (JPLS), and juvenile amyotrophic lateral sclerosis (JALS/ALS2), caused by retrograde degeneration of the upper motor neurons of the pyramidal tracts. Here, we describe 11 individuals with IAHSP, aged 2-48 years, with IAHSP from three unrelated consanguineous Iranian families carrying the homozygous c.1640+1G>A founder mutation in ALS2. Three affected siblings from one family exhibit generalized dystonia which has not been previously described in families with IAHSP and has only been reported in three unrelated consanguineous families with JALS/ALS2. We report the oldest individuals with IAHSP to date and provide evidence that these patients survive well into their late 40s with preserved cognition and normal eye movements. Our study delineates the phenotypic spectrum of IAHSP and ALS2-related disorders and provides valuable insights into the natural disease course
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