301 research outputs found
Use of bioethanol byproduct for supplementary cementitious material production
Corn stover has the potential for use as a supplementary cementitious material (SCM) for concrete. The impact of distilled water and dilute acid pretreatments and post-treatments on the pozzolanic reactivity of corn stover ash (CSA) was studied. Additionally, the potential use of a bioethanol byproduct called high lignin residue (HLR) for SCM production was examined. Pretreated CSA and high lignin residue ash (HLRA) increased the early reactivity of cement paste when used as 20% replacement of cement in the system whereas unpretreated CSA was found to severely suppress the hydration reaction. The highest compressive strength was obtained from samples containing HLRA
Psychometric properties of the Persian version of co-rumination questionnaire
Background: Although growing studies support features of co-rumination as a vulnerability factor in internalizing symptoms and positive factor in friendship, little attention has been paid to the psychometric properties of the Co-Rumination Questionnaire (CRQ). Objectives: This study aimed to determine the psychometric properties of the Persian version of this questionnaire. Methods: This research is a descriptive-exploratory study and 550 high school students who were selected by random cluster sampling from schools in Tehran. They completed CRQ, Beck depression inventory-II (BDI-II), and ruminative response scale (RRS) from winter 2014 to summer 2015. Construct validity, internal consistency reliability, and factor structure were investigated. Results: The factor analysis identified two interpretable factors with the eigenvalue higher than 2. The results from concurrent validity measurement in the current study showed that co-rumination has a positive correlation with depression signs (P < 0.01) and rumination response style (P < 0.01). The CRQ validity was determined using the half-split method employing Spearman-Brown (0.82) and Guttman correlation test (0.81) and internal consistency (0.90). According to these values, this questionnaire has acceptable internal consistency reliability. Conclusions: The Persian version of CRQ has reliability and validity for assessing co-rumination among adolescent participants. This study provides primary evidence on the applicability of the Persian version of the CRQ in the Iranian population. Copyright © 2020, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited
The serological study of cystic echinococcosis and assessment of surgical cases during 5 years (2007- 2011) in Khorram Abad, Iran
Background: Echinococcus granulosus is a cestode whose larval stage causes cystic echinococcosis in wild animals, livestock, and human.Objective: The aim of this study is to highlight the seroepidemiology of E. granulosus infection and surgical cases in the general population of Khorram Abad district, southwest of Iran.Materials and Methods: Anti.E. granulosus antibodies were tested in 617 inhabitants in Khorram Abad by enzyme.linked immunoassay and antigen B. The surgical cases of cystic echinococcosis were investigated in Shohaday.e.Ashayer Hospital of Khorram Abad (as a referral center) from 2007 to 2011.Results: In total, 95 (15.4%) of the 617 participants (mean age 39.6 } 17.6 years) had anti.E. granulosus antibodies. Prevalence of infection was more in males (60%) than females (40%), and showed statistical significance (P < 0.001). High.titer antibodies were most prevalent among the subjects aged 20-29 years. There was significant association between the presence of Echinococcus antibodies and the sector of residence, education of volunteers, and occupation (P < 0.05). According to hospital records, 58 cystic echinococcosis cases were referred to the hospital during the 5 years. Among the cases, 28 (48.3%) were men and 30 (51.7%) were women. They were between 4 and 74 years of age (36.6 } 18.9 years). The liver was the organ where most of the hydatid cysts (51.7%) were located, followed by lungs (20.7%).Conclusion: This is the first report of the seroprevalence and contributing factors for E. granulosus infection in the general population in Khorram Abad. The findings confirm the importance of diagnosing human cystic echinococcosis in these regions, given the prevalence rates of surgical cases during the last 5 years, and need further evaluation of the risk factors present.Key words: Cystic echinococcosis, hospitals records, hydatidosis, seroepidemiolog
Effect of peak power on microstructure, mechanical and tribological properties of W-Ti-C-N(O) ceramic films produced by hybrid sputtering
This research investigates the impact of peak power (from 44 to 105 kW) on the structural and tribological
properties of W-Ti-C-N(O) films. Chemical analysis of the coatings, using energy-dispersive spectroscopy and
Raman spectroscopy, indicates that increasing target power results in a rise in the oxygen (from 2.6 to 12.0 at%),
carbon (from 19.7 to 32.4 at%), and sp3 (from 9.8% to 24.3%) content. Morphological and topographical
analysis reveal that an increase in target power causes a transition from a columnar structure (with nodular
grains) to a dense structure (with textured grains). The indentation and dry sliding tests demonstrate that the
maximum level of H/E2 (0.00047 GPa-1) is achieved, along with a low wear rate of 8.1 × 10-7 mm3/N.m.info:eu-repo/semantics/publishedVersio
Influence of Al2O3 reinforcement on precipitation kinetic of Cu-Cr nanocomposite
In this paper, the kinetic of precipitation process in mechanically alloyed Cu-1 wt.% Cr and Cu-1 wt.% Cr/3 wt.% Al2O3 solid solution was compared using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The ageing kinetics in Cu¿Cr and Cu¿Cr/Al2O3 can be described using Johnson¿Mehl¿Avrami (JMA) and Sestak¿Berggren (SB) models, respectively. These different behaviors have been discussed in details. It was found that in presence of Al2O3 reinforcement, the ageing activation energy is decreased and the overall ageing process is accelerated. This behavior is probably due to higher dislocation density previously obtained during ball milling and Al2O3¿Cu interface. TEM observations confirm that Al2O3¿Cu interface and structural defects act as a primary and secondary nucleation sites, respectively.Gobierno de España ENE 2007-67926-C02-0
Effect of substrate bias voltage on structural and tribological properties of W-Ti-C-N thin films produced by combinational HiPIMS and DCMS co-sputtering
Protective multi-component thin films at the surface of cutting tools have been significantly developed to reduce
wear and friction. The present work investigates the effect of substrate bias voltage on the structural-tribological
relations of W-Ti-C-N thin films produced by HiPIMS and DCMS co-sputtering. Chemical analysis of the coatings
is obtained and composite phase structure is revealed. Morphology of the coatings illustrates that defectless
surfaces may be achieved. Topographical parameters are investigated by employing graphical software. Indentation,
scratch and pin-on-disk tests (pin is AISI 52100 steel) are applied to study mechanical behaviors of the
films. To produce a wear-resistant film, a median bias voltage ( 60 V) and as a result, optimum content of
tungsten concentration (19.2 at. %), grain size (42.8 nm) and average peak interval (188 nm) is required. Finally,
a model based on the representative volume element is developed to show crack propagation and delamination.info:eu-repo/semantics/publishedVersio
Psychometric properties of the Persian version of co-rumination questionnaire
Background: Although growing studies support features of co-rumination as a vulnerability factor in internalizing symptoms and positive factor in friendship, little attention has been paid to the psychometric properties of the Co-Rumination Questionnaire (CRQ). Objectives: This study aimed to determine the psychometric properties of the Persian version of this questionnaire. Methods: This research is a descriptive-exploratory study and 550 high school students who were selected by random cluster sampling from schools in Tehran. They completed CRQ, Beck depression inventory-II (BDI-II), and ruminative response scale (RRS) from winter 2014 to summer 2015. Construct validity, internal consistency reliability, and factor structure were investigated. Results: The factor analysis identified two interpretable factors with the eigenvalue higher than 2. The results from concurrent validity measurement in the current study showed that co-rumination has a positive correlation with depression signs (P < 0.01) and rumination response style (P < 0.01). The CRQ validity was determined using the half-split method employing Spearman-Brown (0.82) and Guttman correlation test (0.81) and internal consistency (0.90). According to these values, this questionnaire has acceptable internal consistency reliability. Conclusions: The Persian version of CRQ has reliability and validity for assessing co-rumination among adolescent participants. This study provides primary evidence on the applicability of the Persian version of the CRQ in the Iranian population. Copyright © 2020, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited
Comparing the Effects of Lidocaine Spray versus Intravenous Lidocaine Administration after Laryngeal Mask Airway (LMA) Insertion
Background and Objective: Laryngeal Mask Airway (LMA) is commonly used in short-term surgical anesthesia. Intravenous lidocaine is used for better patient tolerance after LMA insertion. Regarding the side effects of intravenous lidocaine, the aim of this study is to compare the effect of lidocaine spray versus intravenous lidocaine on blood pressure, heart rate, sore throat, cough, laryngospasm, and other side effects including nausea, vomiting, and convulsions after LMA insertion.
Methods: This double-blind randomized clinical trial was conducted on 120 patients aged 18-65 years with indications for short-term elective eye surgery, in 2 equal groups of 60 people. The first group was given 1% intravenous lidocaine at the rate of 1.5 mg/kg, and the second group was administered with 5 puffs of 10% lidocaine spray in the throat. Then, blood pressure by a sphygmomanometer, heart rate by a heart rate monitoring system, sore throat intensity based on VAS criteria, and cough intensity based on mild, moderate and severe were measured and compared in the two groups.
Findings: 79 men (65.8%) and 41 women (42.2%) participated in this study. Clinically, there was no significant change in blood pressure in the two groups. The mean intensity of sore throat two and three hours after waking up in lidocaine spray group (0.51±1.33 and 0.41±1.07) compared to intravenous lidocaine (1.15±2.02 and 1.9±1.08) showed a significant decrease (p<0.05). Also, there were no significant changes in heart rate, cough and laryngospasm between the two groups. In addition, no cases of nausea, vomiting and seizures were found in the two groups.
Conclusion: Based on the results of this study, lidocaine spray can be suggested to reduce the severity of sore throat caused by LMA insertion
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