Flow Control Using Traveling Waves

Flow separation is the detachment of boundary layer from a surface, which is associated with aerodynamic loss. In this work, the feasibility of controlling flow separation by backward (toward downstream) traveling waves is studied using large-eddy simulations (LES) of traveling waves (1) within an incompressible turbulent channel to investigate the impact of traveling wave parameters such as wave speed and wave steepness, (2) on an inclined plate and suction side of a NACA0018 airfoil at stall angle of attack where the flow is massively separated, and (3) within a compressible wavy turbulent channel. For (3), an LES framework for compressible flow is developed and combined with the curvilinear immersed boundary (CURVIB) method. Both incompressible and compressible frameworks are validated. The incompressible framework is validated for a fully developed turbulent channel, a pitching airfoil, two-dimensional inclined plate, and an NREL PHASE VI wind turbine. The compressible framework is validated by performing simulations for isotropic decay, subsonic and supersonic turbulent channel, and shock diffraction by a cylinder. The results of the simulations of actuated airfoil and plate reveal that low-amplitude backward traveling waves can postpone stall. Moreover, it is found for the first time that traveling waves are more effective than other types of oscillations, e.g., standing waves and pitching motion, in delaying stall because traveling waves can directly increase the axial momentum of the fluid in addition to triggering boundary layer instabilities, which occurs in all type of flow control with periodic excitation. In addition to the axial momentum, the traveling waves increase the lateral velocity of the fluid near the surface, which tends to separate the flow. The scalings of axial force and lateral velocity, which depend on amplitude, wavelength and frequency, were derived analytically using elongated body theory (EBT). Based on the scalings and the results, in contrast to common belief, wave speed (the main parameter for the axial force) is not the only parameter for flow reattachment, and amplitude, wavelength and frequency individually can impact flow separation by triggering instabilities or increasing the lateral velocity

Niosomal Formulation for Co-Administration of Hydrophobic Anticancer Drugs into MCF-7 Cancer Cells

Introduction: Designing and developing drug delivery systems has received tremendous attention during the last decade. The treatment of cancer cells is a complicated process due to the existence of different biological pathways. Therefore, the co-delivery of different drugs could have a synergic effect on the treatment process.Materials and Methods: In this study, different types of span (20, 60, 80) and cholesterol were utilized to formulate tamoxifen/curcumin co-loaded niosomes as a drug carrier system for breast cancer chemotherapy. Niosome characterization was performed through a set of instrument analysis techniques including scanning electron microscopy (SEM) and dynamic light scattering. Release behavior was studied by dialysis method at (pH = 5, 7.4). The stability was monitored during two months storage at two temperatures (4 and 25 °C). Cytotoxicity activity of the best niosomal formulation were assessed on MCF-7 cells, using MTT assay.Results: The optimal niosomal formulation with span 80 and lipid-to-drug molar ratio of 20 was selected, with maximum encapsulation of both drugs and minimum size. Drug release behavior at physiological pH (7.4) (with significant drug release under acidic conditions (pH = 5) and storage stability of up to 2 weeks with little change in drug efficacy and measurement makes it a proper candidate for breast cancer treatment.Conclusion: Finally, the results of this study showed the importance of creating highly biocompatible formulations, allowing the simultaneous transfer of two drugs with controlled release to cancer cells which could improve the chemotherapy process with the synergistic effect of the two drugs

Primjena regresijskog modela u analizi ključnih čimbenika koji pridonose težini nesreća u građevinskoj industriji u Iranu

Construction industry involves the highest risk of occupational accidents and bodily injuries, which range from mild to very severe. The aim of this cross-sectional study was to identify the factors associated with accident severity rate (ASR) in the largest Iranian construction companies based on data about 500 occupational accidents recorded from 2009 to 2013. We also gathered data on safety and health risk management and training systems. Data were analysed using Pearson’s chi-squared coefficient and multiple regression analysis. Median ASR (and the interquartile range) was 107.50 (57.24-381.25). Fourteen of the 24 studied factors stood out as most affecting construction accident severity (p<0.05). These findings can be applied in the design and implementation of a comprehensive safety and health risk management system to reduce ASR.Građevinska se industrija povezuje s najvišim rizikom od nesreća na radu i tjelesnih ozljeda u rasponu od blagih do vrlo teških. Cilj ovoga presječnog istraživanja bio je utvrditi čimbenike povezane s indeksom težine nesreća među najvećim građevinskim tvrtkama u Iranu na temelju podataka iz 500 izvještaja o nesrećama na radu prikupljanih od 2009. do 2013. Usto smo prikupili podatke o upravljanju rizikom za sigurnost i zdravlje radnika te o njihovu obrazovanju u tom pogledu. Podaci su analizirani Pearsonovim hi-kvadratnim testom i modelom višestruke regresije. Medijan indeksa težine nesreća (i interkvartilni raspon) iznosio je 107,50 (57,24-381,25). Na težinu nesreća najviše je utjecalo četrnaest od 24 ispitana čimbenika (p<0,05). Ovi rezultati mogu biti korisni u osmišljavanju i uspostavi obuhvatnih sustava upravljanja rizikom za sigurnost i zdravlje radnika kako bi se smanjio indeks težine nesreća na radu

Effect of interlayer thickness on mechanical properties of steel/polymer/steel laminates fabricated by roll bonding technique

Nowadays, metal/polymer/metal laminates are extensively used in various industries due to their unparalleled properties. In this study, the roll bonding process was employed for lamination of low carbon steel (St14) and semi-melted thermoplastic polyurethane sheets. The T-peel and Single Lap Shear (SLS) tests were conducted to determine the optimal rolling speed to achieve the highest bond strength between the polymer core and the steel skins. Then, with the goal of investigation of the effect of polymer volume fraction on the mechanical properties of laminates, the lamination process was performed at the optimal rolling speed and various thickness reductions. The uniaxial tensile tests were conducted at three directions of 0°, 45°, and 90° with respect to rolling direction for the skin sheet and four different laminates. The results of both T-peel and SLS tests recommend the lowest rolling speed (25 rpm) to acquire maximum bond strength. The results of tensile tests show that the mechanical properties of the laminates depend on the sample direction. Abstract-Nowadays, metal/polymer/metal laminates are extensively used in various industries due to their unparalleled properties. In this study, the roll bonding process was employed for lamination of low carbon steel (St14) and semi-melted thermoplastic polyurethane sheets. The T-peel and Single Lap Shear (SLS) tests were conducted to determine the optimal rolling speed to achieve the highest bond strength between the polymer core and the steel skins. Then, with the goal of investigation of the effect of polymer volume fraction on the mechanical properties of laminates, the lamination process was performed at the optimal rolling speed and various thickness reductions. The uniaxial tensile tests were conducted at three directions of 0°, 45°, and 90° with respect to rolling direction for the skin sheet and four different laminates. The results of both T-peel and SLS tests recommend the lowest rolling speed (25 rpm) to acquire maximum bond strength. The results of tensile tests show that the mechanical properties of the laminates depend on the sample direction. It is also observed that as the volume fraction of the polymer in the laminate structure increases, the yield strength, tensile strength and elastic modulus decrease. The bond strength of the metal/ polymer interface is directly related to the ductility behavior of the laminates

Ubiquinone Ameliorates Hippocampus Injury Induced by Cerebral Ischemia/Reperfusion

Background: Apoplexy is known as a critical issue all over the world and certain parts of the brain are more sensitive to Ischemia/cerebral reperfusion such as the hippocampus. Coenzyme Q10 is a powerful anti-oxidant, which helps in cells membrane durability. Aim: This study attempts to find the effect of coenzyme Q10 on the change of hippocampal area texture after cerebral reperfusion/Ischemia.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Methods: Twenty-four male Wistar rats were organized into 4 groups of six including control, Ischemia, vehicle and experimental groups, with 100 mg /Kg of coenzyme Q10. Coenzyme Q10 was given to the rats 5 days before and 3 days after Ischemia/reperfusion induction. Ischemia was done for 20 minutes by reciprocal blocking of carotid arteries. The rat’s brains were removed and stained by applying the chrysalis fast violet method. The number of viable cells of the hippocampal regions of all 4 groups was counted by Imaging-Pro-Plus software. Statistical analysis of the data was then accomplished by one-way ANOVA and Tukey's test. Results: Findings revealed that the number of viable cells in CA2 and CA3 area reduced following ischemia induction. Whereas, there was no notable change between the control and experimental groups in terms of cells numbers. Besides, there was no remarkable change between the control, experimental and ischemia groups in terms of the number of cells within CA4 area. Conclusion: The results support the use of coenzyme Q10 as a neurotrophic substance and as an adjunctive therapy in patients at risk for ischemic stroke

The Effectiveness of Group Dialectical Behavior Therapy on Emotional Regulation and Rumination in Girls with Traumatic Experience

Introduction: The aim of this study was to evaluate the efficacy of group dialectical behavior therapy on emotional regulation and rumination among female students with traumatic experiences. The traumatic experiences among teenagers and young females have various negative impacts on their future life.Methods: With reference to the Counseling Center of Education Ministry of Mashhad City. 24 female students with traumatic symptoms were selected in this quasi-experimental study to participate in this study. They were assigned randomly into control and experimental groups using the traumatic events questionnaire and the Structured Clinical Interview (SCID). In the pre-test, post-test and two-month follow-up, the difficulties in Emotion Regulation Scale of Gratz and Roemer (DERS) was conducted. The experimental participants spent 14 sessions of group dialectical behavior therapy.Results: The results demonstrated that there were a significant difference between mean scores of emotional regulation difficulties in girls with traumatic experiences who received group dialectical behavior therapy and the mean scores of emotional regulation difficulties in girls with traumatic experiences who did not receive the intervention (P&lt;0.05).Conclusion: With the impact of dialectical behavior group therapy on the cognitive and emotional aspects of female participants with traumatic experiences, students were able to increase their emotional regulation and manage rumination.Declaration of Interest: NoneKey words: Dialectical behavior therapy, Rumination, Emotion regulation, Traumatic experiences

Effect of Tubular Orientation on the Microtensile Bond Strength of Composite-dentin using Universal Bonding Agents

The aim of this study was to evaluate the effect of dentinal tubules orientation on the composite-dentin microtensile bond strength using universal adhesives. A total of 36 caries-free third molars were selected. The teeth were allocated to (axial, wall) and (occlusal, floor) groups and each group was divided into three subgroups based on the type of bonding used. The specimens were then sectioned to obtain dentin-composite sticks with a binding area of approximately 1 mm2. Then sticks were mounted in the universal testing machine (UTM) at a crosshead speed of 0.5mm/min. Data collection was carried out using two-way ANOVA and T-test. Then, the failure mode of the specimens was observed using a stereomicroscope, and one specimen from each group was evaluated under a scanning electron microscope (SEM). The results of two-way ANOVA showed that the highest and lowest mean microtensile bond strength (μTBS) were observed in the group of Adper Single Bond 2 adhesive (axial, wall) (28.92±8.75) and Single Bond Universal adhesive (occlusal, floor) (12.83±7.90), respectively. On the other hand, there was no significant difference between the three adhesives in the mean of μTBS in the (occlusal, floor)orientation, but the mean μTBS of Adper Single Bond 2 adhisive was significantly higher than that of G-premio and Single Bond Universal adhesives in the (axial, wall) orientation (P=0.05). There was no significant difference in two universal adhesives (P= 0.994). The stereomicroscopic analysis showed that the highest adhesive failure was related to Adper Single Bond 2 in (axial, wall) orientation. However, the failure mode results were nearly identical in both adhesives in the (axial, wall) orientation. The failure mode results were also similar in all three adhesives in the (occlusal, floor) orientation. The dentinal tubules orientation showed no significant effect on the microtensile bond strength of the Gpremio, Single Bond Universal adhesives. Adper Single Bond 2 had a significantly higher μTBS rate in the (axial, wall) orientation, but its μTBS was similar to that of the universal adhesives in the (occlusal, floor) orientation, which was not statistically significant

Effect of 940nm Diode Laser Irradiation on Microtensile Bond Strength of an Etch and Rinse Adhesive (Single Bond 2) to Dentin

Statement of the Problem: Laser can influence bonding mechanism by increasing the penetration depth of adhesive in smear layer. The effect of 940 nm diode laser on microtensile bond strength of adhesive to dentin has not been investigated in previous studies. Purpose: The aim of this study was to evaluate the effect of 940 nm diode laser irradiation on microtensile bond strength of Single Bond 2 to dentin. Materials and Method: Thirty sound premolars extracted for orthodontic reasons were randomly divided into five groups as follows: G1 or control: etching+ Single Bond2 (SB); G2: diode laser (940 nm wavelength, 1W power, continuous mode)+ etching+ SB; G3: etching+ laser irradiation+ SB; G4: etching+ SB+ laser irradiation+ adhesive curing; G5: etching+ laser irradiation+ SB +laser irradiation +adhesive curing. After the bonding procedure, Z250 composite resin was applied on the dentin surface in three layers of 2 mm thickness. After 24 hours of immersion in distilled water at 37°C and thermocycling for 1000 thermal cycles, the teeth were sectioned into 1mm2 sticks. The microtensile bond strength was measured using a universal testing machine. Bond strength (MPs) was analyzed by one-way ANOVA followed by HSD post hoc Tukey’s test (α=0.05). Results: G4 (38.35±8.99) showed the significant highest bond strength compared to other groups (p= 0.000). G5 (25.16±6.14) showed significantly higher bondstrength than the control group (18.85±4.79) (p= 0.032).Bond strength of G2 (23.39±6.07) and G3 (22.85±5.11) groups was the same and similar to that in the control group (p> 0.05). Conclusion: Based on the results of this study, it may be concluded that dentin surface irradiation with 940 nm diode laser after adhesive application and prior to curing can significantly increase the bond strength of composite to dentin

Sustaining the National Spinal Cord Injury Registry of Iran (NSCIR-IR) in a Regional Center: Challenges and Solutions

Background: The National Traumatic Spinal Cord Injury Registry in Iran (NSCIR-IR), was implemented initially in three hospitals as a pilot phase from 11 Oct 2015 to 19 Jun 2016 and has been active in eight centers from 19 Jun 2016. Poursina Hospital, a trauma care referral center in Rasht, Guilan Province of Iran is one of the registry sites, and has been involved in registering eligible patients since 1 Jan 2016. This study aimed to identify the challenges and solutions for sustaining the NSCIR-IR in a regional center. Methods: This was a mixed-methods study. For the quantitative analysis, a retrospective observational design was used to measure case capture or case identification rate, mapping cases in the registry against those eligible for registry inclusion amongst the register of hospital admissions. For the qualitative component, data was collected using focus group discussions and semi-structured interviews, followed by thematic analysis. Results: From 19 Jun 2016 to 24 Jan 2018, the proportion of case capture (case identification rate) was 17%. The median time between case identification and data entry to the system was 30.5 d (range: 2 to 193 d). Thematic analysis identified a lack of trained human resources as the most important cause of low case identification rate and delay in data completion. Conclusion: Recruitment and education to increase trained human resources are needed to improve case capture, the timeliness of data input and registry sustainability in a regional participating site

Psychometric properties of Persian version of wound-QOL questionnaire among older adults suffering from chronic wounds

BackgroundPatients with chronic wounds experience various biopsychosocial problems which severely affects their quality of life (QoL). Thus, a Persian instrument to assess the QoL of these patients is required. This study aimed to determine the psychometric properties of the Persian version of the wound-QOL questionnaire.MethodsThis methodological study was performed on Iranian patients during 2021–2022. The translation was carried out via forward-backward method. Face validity was addressed with 10 patients and content validity with 12 wound specialists. Construct validity was also assessed by performing exploratory factor analysis (EFA) (n = 100) and convergent validation with EQ-5D-3L plus Pain VAS Score and known-groups validity. The reliability was assessed by internal consistency using Cronbach’s alpha coefficient and test–retest.ResultsA total of 100 patients with chronic wounds were included in the study. Two factors with cumulative variance of 65.39% were extracted during EFA. The results revealed a significant and high correlation between the total scores of wound-QOL questionnaire, the Persian version of EQ-5D-3L (p = 0.000, r = 0.502), and Pain score (0–10; p = 0.000, r = 0.627). The Cronbach’s alpha was 0.743 and stability of the questionnaire (α = 0.872) was confirmed. In confirming the known-groups validity, the results showed that this tool can differentiate the QOL of patients with different wounds.ConclusionThe Persian version of the wound-QOL questionnaire is a valid and reliable questionnaire which can measure the QoL of patients with chronic wounds. This instrument can be used in clinical evaluation as well as research purposes across the Iranian population