University College of Azarabadegan

Abs tractIncome inequality is a major problem in mos t countries, particularly the underdeveloped world.Unequal dis tribution of income weakens the achievement of sus tainable global economic growth and acts as an impasse to achieve the goals of sus tainable development, including the reduction of poverty and hunger in the world.One of the mos t important factors affecting income inequality is the rent of natural resources, which can have different effects depending on the way natural resources are used.This s tudy was conducted to inves tigate the effect of natural resource rent on income inequality, taking into account the role of the shadow economy and the human capital index.For this purpose, the annual data of 1971-2020 and the Markov-switching method were used.The results show that natural resources have a positive and significant effect on income inequality; furthermore, the relationship of shadow economy with income inequality in both regimes (low and high levels of inequality is significantly positive, and the effect of human capital on income inequality in both regimes is negative and significant.This s tudy is presented with recommendations to politicians to promote the legalization of undeclared economic activities and reduce dependence on natural resources as mechanisms to reduce the s tructural problem of income inequality.

Energy harvesting from vortex-induced vibrations (VIV) is gaining more attention in many applied cases. This paper studied the nonlinear dynamics of a tunable VIV-based energy harvester. The energy harvester structure consists of a base-clamped cylinder having an adjustable mass (the tuner) which enables the system to actively synchronize with vortex-shedding frequencies. The Euler-Bernoulli beam theory and the extended Hamilton’s principle are used to extract the nonlinear partial differential equations of the distributed model for the cylinder, tuner motion, harvested voltage, and fluctuated lift force. The reduced-order model of the system of equations is derived via the Galerkin method using modified mode shapes. The method of multiple time scales is employed to obtain the approximated analytical solution of the 1:1 internal resonance of the lumped parameter system. The dynamical response of the system is shown by investigating various parameters of the harvester. Additionally, the locus of the points at which the higher orbits of harvested voltage occur is specified for the tuner equilibrium position. The results show the proposed design significantly increases energy harvesting performance by a factor of 900%. This paper is offered as a contribution towards energy harvester design and optimization with the goal of capturing higher energy orbits.

IntroductionNurses are the largest group of health‐care providers and their clinical decisions have an essential role in patients' clinical condition. Evidence‐based nursing has been proposed as a health‐care method based on the latest findings and evidence. Therefore, we aimed to determine the effect of evidence‐based nursing education on dialysis nurses' clinical decision‐making.Material and MethodsThis single‐blind experimental study conducted in 2021 at dialysis wards of teaching hospitals affiliated to Urmia University of Medical Sciences. In this study, a total of 60 dialysis nurses were recruited using convenience sampling and allocated to two groups of intervention (n = 30) and control (n = 30). Data were collected at three time points of before, 1 week after, and 1 month after the intervention using a demographic questionnaire and the Lauri and Salantera Clinical Decision‐Making Questionnaire (LSCD‐MQ). Nurses in the intervention group received 12 sessions of evidence‐based nursing education, while nurses in the control group received no intervention.ResultsThe results showed the mean score of clinical decision‐making had a significant decreasing trend over time (p < 0.001) so that it decreased significantly 1 week after the intervention (72.83 ± 4.90) compared with before the intervention (69.5 ± 67.34) in the intervention group. Moreover, participants' decision‐making moved toward analytical decision‐making. The results also indicated there was a significant difference between the baseline mean score of clinical decision‐making and the postintervention mean scores obtained 1 week (p = 0.025) and 1 month (p = 0.001) after the intervention. However, this difference was not found to be significant in the control group (p = 1.000).ConclusionsThe study results indicate the positive effect of evidence‐based education on nurses' clinical decision‐making. Therefore, nurses are recommended to apply evidence‐based education methods to improve their level of clinical decision‐making. Health officials are also recommended to hold in‐service evidence‐based workshops to update nurses' knowledge.

In the present work, a Proton-Exchange Membrane Fuel Cell (PEMFC) as a three-dimensional and single phase was studied. Computational fluid dynamics and finite volume technique were employed to discretize and solve a single set of flow fields and electricity governing equations. The obtained numerical results were validated with valid data in the literature and good agreement was observed between them. The main purpose of this paper is to investigate the effect of deformation of the geometric structure of a conventional cubic fuel cell into a cylindrical one. For this purpose, some important parameters indicating the operation of the fuel cell such as oxygen distribution, water, hydrogen, proton conductivity of the membrane, electric current density, and temperature distribution for two voltage differences between the anode and cathode and the proposed models were studied in detail. Numerical results showed that in the difference of voltages studied, the proposed new model had better performance than the conventional model and had a higher current density, in which at V = 0.4 [V], about a 10.35 % increase in the amount of electric current density was observed and the average increment in generated power was about 8 %, which could be a considerable value in a stack of cells. Finally, the discussion of critical parameters for both models was presented in more detail. The core idea of the results is that the Oxygen and Hydrogen utilization, water creation, and heat generation are greater in the new model.

Lelomyosarcoma(LMS) is an uncommon malignant spindle cell tumor of the head and neck region. It is extremely rare in the oral cavity that arises from smooth muscle differentiation. It may arise as primary, radiation-associated, or metastatic tumor. The clinical appearance of these tumors can be deceptively benign and can be mistaken for non-malignant conditions. Here We present a case with atypical leiomyoma of the mandible in a 40-year- old man who referred with complaint of pain and swelling in his jaw. He underwent surgery and histology and immonohistochemestery studies confirmed the diagnosis. After 6 months recurrence occurred. Histologic examination confirmed leiomyosarcoma so he was managed with surgical excision followed by radiotherapy and chemotherapy without any recurrence or metastasis after 2 years of follow-up.

The use of colors in food industry is essential for the creation of new products or their improvement. As an important pigment group, anthocyanin could be used as a natural coloring pigment in foods. This study aims at exploring strategies that result in color stability of anthocyanin in pear‐shaped variety of blueberry (Cornus mas–Macrocarpa). In this study, the effects of different pH values (1, 2, 3, 4) as well as various concentrations (0, 120, 240, 480, 960 mg/L) of five copigments, including tannic, caffeic, benzoic, and coumaric acids, on anthocyanin copigment complexes (ratio 1:1) were investigated. The studied copigments were tannic, caffeic, benzoic, and coumaric acids. Anthocyanin was influenced by the highest concentration of 960 mg/L copigment in the presence of different pHs. Five groups were considered, one of which contained anthocyanin without copigment and the rest consisted of copigments. To evaluate the response of copigmentation through spectrophotometer, absorbance from samples was measured after 30 min of adding copigment to anthocyanin in the range of 450–600 nm wavelengths. The results showed that caffeic acid possessed the greatest anthocyanin stability compared to other copigments and it was the best copigment. An increase in the concentrations of copigments led to a higher level of anthocyanin stability and changes in hyperchromic and bathochromic. Moreover, the results revealed that the strongest hyperchromic effect for all organic acids was observed in pH 2, and the strongest bathochromic changes were observed in pH 4.

We present the case of a 30-year-old man with no past history of disease or recent trauma, who was seen in the emergency room after developing sharp pain in the left hemithorax. Chest roentgenogram showed costopherenic angle blunting and an oval mass in the left mediastinum. A computed tomographic scan showed extrapleural mass with coarse calcifications and pleural effusion, confirmed by magnetic resonance imaging. The tumor was biopsied and removed during thoracotomy. The pathology reported revealed chondrosarcoma, which is a rare cause for a spontaneous massive hemothorax. Invasion of the intercostals vessels by the tumor was the probable cause of hemothorax in this patient.

SummaryGenotypes of Lolium perenne, Festuca rubra, Dactylis glomerata and Holcus lanatus which appeared to be differentially sensitive to acute or chronic SO2 injury were compared in various morphological and physiological studies to examine some possible mechanisms of tolerance. Stomatal number and size showed no relationship with tolerance, but stomatal resistance in clean air showed a relationship with intra‐ and interspecific differences in tolerance to acute injury. Also, acute doses of SO2 increased stomatal resistance in tolerant, but not in sensitive species.Membrane permeability was increased by acute doses of SO2, but there were no differential effects which could be related to tolerance. Uptake of 14CO2 by leaf segments in buffered solution was reduced in the presence of sulphite to a greater extent in genotypes of Lolium perenne sensitive to chronic injury. Prefumigation for 13 months with a low concentration of SO2 increased the sensitivity to sulphite, especially in the sensitive genotypes.The species tolerant of acute SO2 injury, Dactylis glomerata and Holcus lanatus, had lower rates of 14CO2 fixation than sensitive species, and were affected less by sulphite. There were no relationships between prefumigation or sensitivity to chronic injury and the uptake or oxidation of sulphite in three Lolium perenne genotypes. Species sensitive to acute injury absorbed more 35SO2 than tolerant species. Oxidation of the absorbed radioactivity was fastest in the most tolerant and slowest in the least tolerant species.It is concluded that many of the differential responses to acute injury can be explained by avoidance mechanisms. Some potential mechanisms of tolerance to chronic injury are discussed.