Experimental and theoretical investigations of new Schiff base compound adsorption on aluminium in 1 M HCl

The new Schiff base, 2,2\u27-((1Z,1\u27Z)-(((propane-1,3-diylbis(oxy))bis(2,1-phenyle­ne))bis­(me­tha­­nyl­­ylidene))bis(azanylylidene))diethanol, was investigated as a cor­ro­sion inhibitor of aluminium in 1 M HCl. Polarization and electrochemical impedance mea­surements were used for this purpose. Polarization curves showed that the compound is a mixed-type corrosion inhibitor. Also, the results showed an increase in inhibition efficiency as the concentration of the compound increased. The maximum corrosion inhibition effici­ency of approximately 81 % was reached at the concentration of 2 mg/L of the inhibitor. The results of the density functional theory method were consistent with the experimental results. The surface morphology of the samples was examined under atomic force microscopy

Synthesized Schiff Base Acted as Eco-Friendly Inhibitor for Mild Steel in 1N H2SO4

2,2'-((1Z,1'Z)-(((propane-1,3-diylbis(oxy))bis(2,1-phenylene))bis(methanylylidene))bis(azanyly lidene))diethanol (2-PPM) was synthesized. This compound evaluated as novel corrosion inhibitor for mild steel in 1N H2SO4 solution. Polarization study showed that the compound was mixed type inhibitor. Electrochemical impedance study showed that the presence of this compound decreases the double layer capacitance and increases the charge transfer resistance.Weight loss study showed that, the corrosion inhibition property of 2-PPM on the external area of mild steel samples in the solution is mainly depends on the inhibitor concentration and immersion period. Further, the maximum protection efficiency obtained by weight loss technique was 65 %. SEM and AFM results fully support the chemical and electrochemical results

Transmitted vibrations to the wrist and arm of a chainsaw operator: The effect of wood cutting process

Introduction: Due to the non-developed mechanization situation, chainsaw is a widely used tool in Iranian forests. This tool can trigger unwelcome disorders (e.g., white finger syndrome) due to the transmitted vibrations from its handle to the body members. Characterizing these vibrations can result in minimizing the intensity of these disorders. This study aims to investigate the effect of different hardwood species (Beech, Hornbeam, and Alder) on the vibrations transmitted to the wrist and arm. Material and Methods: Experiments are conducted during four operations including Beech-, Hornbeam-, and Alder-cross-cutting and without cutting as the control sample. Vibration accelerations in three directions of a local Cartesian coordinate system are measured at three points including chainsaw handle, operator's arm and wrist. Using the time and frequency spectra of vibration accelerations, root mean square (RMS), total vibration acceleration, total vibration transmissibility, and frequency-weighted vibration acceleration are calculated based on ISO 5349 (2001) and ISO 10819 (2013) standards. The calculated parameters were statistically analyzed in SAS. Results: The results showed that variations in wood species could significantly affect the RMS at all three points. The RMS magnitude decreases from handle towards the arm. Interestingly, a significant variation in vibration transmissibility is observed in different frequencies. This study confirms that body organs can damp the high-frequency vibrations better than the low frequency ones. Conclusion: Although the RMS for cutting operations is less than the control sample, frequency-weighted vibration acceleration and consequently the risk of white finger syndrome is higher in cutting regimes. Furthermore, some vibration accelerations (below 40 Hz for wrist and below 25 Hz for arm) are amplified during transmission despite significant damping in total vibrations

Morphological and Physiological Traits in Seedlings’ Populations Obtained from the Hybridization of Promising Genotypes of Quince ( Cydonia oblonga

Some morphological and physiological traits of seedlings in eight quince populations from seeds obtained in 2015 (350 progenies per population) were evaluated in 2017 and 2018. They resulted from open pollination of ‘Viduja’, KVD2 and KVD4 genotypes as well as from the crossings of ‘Viduja’ × KVD4, KVD2 × ‘Viduja’, KVD2 × KVD4, KVD4 × ‘Viduja’ and KVD4 × KVD2. Populations showed significant differences in some measured traits, including height and diameter of seedlings, canopy width, annual growth, leaf iron, and chlorophyll content, as well as catalase and peroxidase activities. Based on the results of descriptive statistics, a high variation coefficient was observed in canopy width, peroxidase activity, chlorophyll, and iron content traits. Results of simple correlation showed that there were significant positive correlations between leaf iron content and catalase activity as well as canopy width with both annual growth and leaf length. Cluster analysis among populations based on total traits divided the populations into four distinct groups. The role of the female parents was visible in reciprocal crosses of ‘Viduja’ × KVD4 and KVD2 × KVD4, but all populations with similar female parents were not grouped in the same clusters

A Model for Education of Entrepreneur Students in Elementary Schools

Background and Purpose:   The aim of this study was to provide a Model for Education of Entrepreneur Students in Elementary. Metod: The statistical population in the qualitative section includes experts in the field of entrepreneurship and in the small part of the managers and experts of the Chaharmahal and Bakhtiari province and entrepreneurship faculty of the Faculty of Entrepreneurship of Tehran University in 1397 (N = 684).Sample size in the qualitative section was estimated based on the data saturation principle (10 people) and in the quantitative section 297 people were estimated based on Cochran formula. A qualitative sampling was used to select the sample in the qualitative section and in the quantitative section a stratified sampling was used. The data collection tool was a qualitative, semi-structured interview and a researcher-made questionnaire in the quantitative section. The face validity of the questionnaire was verified through trial and content validity through expert judgment and convergent validity through the calculation of the mean of the variance extracted. The reliability of the questionnaire was obtained through Cronbach's alpha for the whole questionnaire of 0.84. To analyze the data in the qualitative section, open and axial coding and in the quantitative part of the AVE, AVE, Kolmogorov-Smirnov, exploratory factor analysis, confirmatory factor analysis and t-tests were used. Results: The results obtained to identify 6 dimensions and 41 indicators led to the naming of the following: individual, social, economic, structural, behavioral, and environmental. In addition, 9 methods, 7 infrastructure and 7 requirements were also identified for the development of entrepreneurial students through this model. Conclusion: Other results showed that the current status of the dimensions, indicators and methods, infrastructure and requirements for the education of the student is lower than the average of the society. 21 The executive mechanism was also developed to educate entrepreneurial students in the elementary degree agreed upon by a sample of research. Model 6 includes a philosophy and objectives of the model, theoretical foundations, dimensions and indicators, infrastructures and requirements, and the implementation mechanism for raising entrepreneurship in the elementary school, and its degree of appropriateness was 95 percent confirmed by experts

Experimental investigation of new compound adsorption on carbon steel in 1M HCl

117-123The effect of new compounds named, 6,6'-(((2,2-dimethylpropane-1,3-diyl)bis(azanediyl))bis(methylene))bis(2- methoxyphenol) (RSH) on the corrosion inhibiting of ST- 37 low carbon steel in 1.0 M HCl has been studied. The inhibitor effects on the corrosion behaviour of the samples have been determined at three different concentrations, 0.5, 1.0, 1.5 and 2.0 mg/L. Weight loss, polarization curves, AC impedance measurements and Atomic Force Microscopy (AFM) have been utilized to study the corrosion behaviour of carbon steel in corrosive environment in the presence and absence of new ligand. Results show that the inhibition occurs through adsorption of the inhibitors molecules on the metal surface. The inhibition efficiency was found to increase with increasing inhibitor’s concentration. Polarization data indicated that this compounds act as mixed-type inhibitors. The corrosion efficiency of RSH at an optimal concentration of 2mg/L is 86. The adsorption of inhibitors follows the Langmuir isotherm. The values of free energy of adsorption in the presence of the corrosion inhibitor are around -32 KJmol-1, which indicate chemiosorption of the molecules. Powerful Atomic Force microscopy is used for the surface morphology studies

Team-based assessment of professional behavior in medical students

Introducrion: Self and peer assessment provides important information about the individual’s performance and behavior in all aspects of their professional environment work. The aim of this study is to evaluate the professional behavior and performance in medical students in the form of team based assessment. Methods: In a cross-sectional study, 100 medical students in the 7th year of education were randomly selected and enrolled; for each student five questionnaires were filled out, including one self-assessment, two peer assessments and two residents assessment. The scoring system of the questionnaires was based on seven point Likert scale. After filling out the questions in the questionnaire, numerical data and written comments provided to the students were collected, analyzed and discussed. Internal consistency (Cronbach’s alpha) of the questionnaires was assessed. A p<0.05 was considered as significant. Results: Internal consistency was acceptable (Cronbach’s alpha 0.83). Interviews revealed that the majority of students and assessors interviewed found the method acceptable. The range of scores was 1-6 (Mean±SD=4.39±0.57) for the residents' assessment, 2-6 (Mean±SD=4.49±0.53) for peer assessment, and 3-7 (Mean±SD=5.04±0.32) for self-assessment. There was a significant difference between self assessment and other methods of assessment. Conclusions: This study demonstrates that a team-based assessment is an acceptable and feasible method for peer and self-assessment of medical students’ learning in a clinical clerkship, and has some advantages over traditional assessment methods. Further studies are needed to focus on the strengths and weaknesses

Different causes of referral to ophthalmology emergency room

Background: Eye-related complaints compose approximately 1-6% of complaints of patients referring to general emergency ward around the world. Eye injuries are the most common cause of referral to eye emergency ward. To understand the impact of eye injuries in Iran and to plan preventive strategies, it is important to understand the complete magnitude of the problem with regard to true population-based data and standard reproducible definitions. Aim: The main goal of this study was to identify the major causes of referrals to eye emergency ward in patients with eye-related complaints in an eye referral Hospital in Iran. Settings and Design: In a cross-sectional study, 3150 patients who referred to Farabi Hospital emergency ward, Tehran, Iran, from January to December 2007 were included in the study and their detailed information were recorded. Materials and Methods: The patients′ demographic data, medical history and final diagnosis were recorded in a questionnaire. Results: The mean age of patients was 33.2±16.8 years and 2380 patients (75.6%) were males. While 299 patients (9.5%) were referred for non-urgent reasons, work-related injuries were the most common cause of referral (955 patients; 30.3%). In patients referred due to trauma (1950 patients), work-related injuries occurred in 955 patients (49%) and occurred accidentally (by chance) in 819 patients (42%). The majority of patients referred with traumatic injuries were males (1708 patients; 87.6% versus 242 patients; 12.4%). The most common etiologies of eye trauma (1950 patients) were metal filings (814 patients; 41.8%), blunt trauma (338 patients; 17.3%), fireworks (236 patients; 12.1%) and sharp objects (222 patients; 11.4%). Globe injury was diagnosed in 1865 patients (95.7%) of trauma cases. In patients referred due to non-traumatic reason (1200 patients), eye infection occurred in 482 patients (40.2%) and 299 patients (24.9%) were referred for non-urgent reasons. There was little difference between the frequency of non-trauma-related problems among genders (672 male patients; 56% versus 528 female patients; 44%). Conclusions: This study identified multiple risk factors whose presence significantly increases severity of an eye injury. Male gender, youth and unprotected eyes during high-risk activities such as sports and certain jobs are risk factors for eye injuries. In patients referred due to non-traumatic reasons, males and females are similar. Considerable proportion of non-trauma-related problems was due to eye infection, that one of the most important reasons may be connected to the increasing use of contact lenses in our target population. Thereupon, we need for further educative and preventive interventions at the level of general population