Showing 4 results for Voc
Masoumeh Sadri Khanlou, Mohammadreza Monazzam, Kamal Azam, Alireza Mortezapour, Seyed Abolfazl Zakerian,
Volume 9, Issue 3 (9-2019)
Abstract
Introduction: Nearly a third of people work in jobs that use voice to be part of their work. Teachers as the largest group of professional vocal users, are at risk of vocal disorders. The aim of this study was to investigate the effect of different risk factors on vocal disorders in teachers.
Material and Methods: This is a cross-sectional and descriptive-analytic study that was conducted on 73 primary and secondary male and female school teachers in Saveh in 2017 by random sampling. The researcher-made questionnaire on risk factors affecting verbal disorders with the aim of identifying risk factors and a Voice Handicap Index (VHI) questionnaire (30 items) aimed at evaluating verbal disorders and symptom questionnaire were used in this study. All of them have been shown to be valid and reliable in previous studies. Data were analyzed using t-test and chi square statistical tests by SPSS ver.24.
Results: The reliability of the researcher-made questionnaire on the risk factors affecting vocal disorders was confirmed by Cronbach’s alpha (0.736) and its validity was confirmed by the experts regarding the adequacy of the number of questions, the lack of ambiguity and the assessment of content fitness. According to our gathered data, vocal disorders were observed in 55% of the teachers. Also the results showed the rate of vocal disorders in female teachers is far higher than male teachers. Functional disturbance of vocal cords and allergy as general risk factors, teaching tools and poor air quality as environmental risk factors and inadequate vocal rest and job stress as occupational risk factors contributed to increasing vocal disorders in teachers. Among the symptom associated with verbal disorders in teachers, vocal fatigue and hoarseness were more common in comparison with other symptoms.
Conclusion: Due to the prevalence of vocal disorders in half of the teachers and the impact of general, environmental and occupational risk factors, it is necessary to identify and control the risk factors of vocal disorders in teachers. It can also be concluded that teachers can enjoy a healthy voice by considering the principles of ergonomics and occupational health.
Zahra Alaei, Roohollah Ghasemi, Mohammad Reza Pourmand, Ali Karimi, Ensieh Masoorian, Farideh Golbabaei,
Volume 12, Issue 2 (6-2022)
Abstract
Introduction: Volatile organic compounds are the most common pollutants in the air, and among them, toluene is the most common form, which is toxic resulting in liver and kidneys damages. Regarding the fact that this compound is widely used in various chemical industries, implementing an efficient method for controlling its concentration is of great importance. The comparative survey of the capability of virgin activated carbon with the one immobilized by pseudomonas putida PTCC, and also the performance of the biofiltration system involving pseudomonas putida bacteria immobilized on activated carbon for the adsorption and degradation of toluene from the air as well as regenerating the activated carbon were aimed in the present study.
Material and Methods: The microbial growth process was initiated by incubation of pre-culture in a rotary shaker, at 150rpm overnight. After 4 days, the strain pseudomonas putida, PTCC No: 1694 was immobilized on a certain amount of activated carbon. Subsequently, an airstream containing toluene was introduced into the biofilter, and the inlet and outlet concentrations of toluene were measured.
Results: The obtained results illustrated that the increase in the volume of the media and decrease in the gas flow rate significantly enhances efficiency. The great performance of the biofilter was confirmed by the high efficiency of the immobilized activated carbon which exhibited 89% yield during 14 hours. On the second cycle, the biofiltration system was able to adsorb toluene at an efficiency of 81%, while the virgin activated carbon exhibited far less efficiency with the value of 28%.
Conclusion: The provided results demonstrated the feasibility and reusability of the biofilter system for toluene removal. The proposed technique also extends the activated carbon’s capacity, which could be a potential solution to re-use the activated carbon in industrial applications.
Zeinab Rostami, Mohammad Reza Abedi, Parisa Nilforooshan,
Volume 13, Issue 4 (12-2023)
Abstract
Introduction: Due to the lack of an instrument for measuring the career issues of those with bipolar disorder, the present study was conducted to develop and examine the psychometric characteristics of the Career Issues Inventory for Persons with Bipolar Disorder (CII-BD).
Material and Methods: To check the diagnostic validity, via purposive sampling and interviews by a psychiatrist, 108 people were selected from two sample groups (53 normal people and 55 participants with bipolar disorder). The items were extracted from three sources including scientific articles related to the career issues of bipolar people, interviews with individuals with bipolar disorder, and interviews with experts using the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) systematic qualitative method. Finally, the items of the CII-BD were reduced to 81 questions. Content, construct, and convergent validity plus factor analysis of CII-BD were also examined. The reliability of CII-BD was evaluated by internal consistency and test-retest method with seven weeks intervals after the initial implementation of the CII-BD.
Results: The convergent validity of the sum score of CII-BD with the sum score of the symptom inventory of people with bipolar disorder among the sample of normal people and the sample of persons with bipolar disorder was (r=0.79, P<0.01, N=53) and (r=0.78, P<0.0001, N=53) respectively. In construct validity examination, nine subscales were extracted using the factor analysis method with varimax rotation, which included communication problems, poor work performance, insecurity, grandiosity, unreliability, change-seeking, vulnerability, lack of boundaries, and lack of self-control towards the opposite sex. In the reliability analysis, Cronbach’s alpha coefficient was 0.96 (N=55, participants with bipolar disorder) and 0.86 (N=53, normal people), respectively, P<0.05, showing the high internal consistency of CII-BD. The test-retest correlation coefficient of the sum scores of the CII-BD was r = 0.91, P < 0.01, which indicated the credible stability of the CII-BD.
Conclusion: The CII-BD is a valid and reliable instrument to measure the specific career issues of bipolar persons and their early vocational rehabilitation. It is suggested that future research should focus on choosing a job and job placement for bipolar disorder persons.
Akram Tabrizi, Mostafa Jafarizaveh, Hamid Shirkhanloo, Farideh Golbabaeie,
Volume 14, Issue 4 (12-2024)
Abstract
Introduction: Volatile organic compounds (VOCs) are hazardous toxic pollutants in the air, which are released from various industrial sources. Due to the adverse effects of xylene on health, the effective removal of VOCs from the air by nano sorbents is crucial. In this study, nanographene (NG) and nanographene oxide (NGO) were used as adsorbents to investigate the efficiency of xylene removal.
Material and Methods: In this study, in order to investigate the absorption efficiency of nanographene and nanographene oxide after the synthesis of nano absorbents in a dynamic system, xylene vapor was produced in a chamber in pure air and stored in a Tedlar sampling bag and then transferred to the adsorbent. Subsequently, the effect of various parameters such as xylene concentration, inlet air flow rate, and absorbent mass values at 32% humidity and 25°C temperature on the absorption rate and performance of the desired absorbents was investigated. Finally, the gas chromatographic flame ion detector (GC-FID) determined the concentration of xylene in air after the adsorption-desorption process.
Results: The average adsorption efficiencies for NG and NGO were found to be 96.8% and 17.5%, respectively. The characteristics of the NG and NGO adsorbents indicated that the particle size range was less than 100 nanometers.
Conclusion: The results demonstrated that the adsorption efficiency of NG for the removal of xylene from the air is higher than that of NGO. The GC-MS method validated the proposed approach in real air samples.
