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متن کامل


اطلاعات دوره: 
  • سال: 

    1401
  • دوره: 

    12
  • شماره: 

    47
  • صفحات: 

    75-93
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    170
  • دانلود: 

    11
چکیده: 

Background: The expansion of the use of audio and video media technology has faced society with many medical, cultural and economic challenges. In the meantime, excessive use of mobile phones can cause many problems. Objective: The aim of this study was to construct and validate a questionnaire on physical and psychological injuries of mobile phones. Method: The method of the present study was descriptive-correlational and confirmatory factor analysis. The statistical population of the study consisted of all citizens of Khorramabad with a diploma or higher in 1399, which was selected as a statistical sample by available sampling method of 200 people online and virtual. Results: The results showed that the factorized physical and psychological harm questionnaire of cell phone with 42 questions and 10 components (fear of loss, vibration syndrome, duck syndrome, nomophobia, insomnia, hearing problem, eye syndrome, tunnel and neck syndrome SMS) and has good reliability, validity and flexibility in terms of psychometrics. Discussion and Conclusion: The questionnaire of factor analysis of physical and psychological injuries of mobile phones can be used to identify and study the physical and psychological injuries of mobile phones.

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نویسندگان: 

Baghernejhad Elnaz

اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    11
  • شماره: 

    2
  • صفحات: 

    29-60
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    195
  • دانلود: 

    29
چکیده: 

ABSTRACT Despite a wide range of components and criteria affecting travel behavior presented through empirical research, the results of these studies are inconclusive, which could be due to the difference between these components and criteria in the study areas. Therefore, this research presented a method to determine which factors in different physical developments affect travel behavior due to the differences in various physical developments. The required information was collected through 271 questionnaires at the level of three neighborhoods of Monirieh, Koye Bimeh, and Koye Golestan in Tehran, Iran, as the old, conventional, and new neighborhoods, respectively. ANOVA test was exerted to analyze the significant difference between different development patterns in three neighborhoods. Dunnett's T3 was applied to determine which neighborhood caused the difference between groups. Also, the factors affecting travel behavior were obtained based on exploratory factor analysis indicators. Finally, by comparing the results of the ANOVA test and regression analysis, it was discovered that factors such as car ownership, dependence and pro-liking for private cars, density and access to educational centers and parks, access to medical and service centers, and variety and density of retail stores had been introduced as the factors affecting travel behavior due to the differences in development patterns. However, proximity to the public transportation station, accessibility preferences in choosing a residence, dependence, and pro-liking for other than a private car, having a license, number of children under five years old, and age have influenced travel behavior regardless of the variation between neighborhoods. Extended Abstract Introduction Finding factors affecting travel behavior has been one of the main concerns of transportation planners. However, in the last two decades, the importance of the influence of the features of the built environment, including land use, along with demographic-economic characteristics, travel behavior, and attitudes of people, has been raised by urban planners. Studies seek to find factors affecting travel behavior, especially land use characteristics. Despite presenting a wide range of components and criteria affecting travel behavior, the results of the studies are inconclusive, which could be due to the difference between these components and criteria in the study areas. Therefore, this research presented a method to determine which factors in different physical developments affect travel behavior due to the differences in various physical developments. In order to do this, it must first be determined whether the study areas/different development patterns have a significant difference in terms of travel behavior or not. In case of a positive answer to the previous question, the following question is which study areas caused this difference. The next question arises: -Which physical and non-physical characteristics affect travel behavior due to distinctions between different development patterns?   Methodology The present research method is analytical and experimental based on quantitative methods. This research chose the frequency of travel by private car, public transportation, and walking as the travel behavior. According to the research's purpose, indicators and criteria affecting travel behavior were extracted after reviewing the theoretical and experimental literature. Then, the required information was collected through 271 questionnaires at the level of three neighborhoods of Monirieh, Koye Bimeh, and Koye Golestan as the old, conventional, and new neighborhoods, respectively. The questionnaire was compiled as a Likert scale in five parts of travel information, demographic-economic characteristics, perceptual characteristics of land use, travel habits, and access preferences of people in choosing their residence. ANOVA test was used to analyze the significant difference between different groups of a characteristic (here, different development patterns or the three case studies). Dunnett T3 was exerted to determine which neighborhood caused the difference between groups. Also, the factors affecting travel behavior were obtained based on exploratory factor analysis indicators. Finally, by comparing the results of the ANOVA test and regression analysis, it was discovered which factors affecting travel behavior were due to the differences in study areas and which factors affect travel behavior regardless of development patterns.   Results and discussion This research aims to identify the factors affecting travel behavior due to the differences in development patterns. In this regard, the findings in line with the first research question show that the frequency of three modes of travel, by private car, transportation, and pedestrian, differ significantly in the three neighborhoods. Furthermore, ANOVA test results depict that there is a significant difference between these three neighborhoods in terms of factors affecting travel behavior, such as perceptually environmental characteristics of the neighborhood, dependence and pro-liking for personal cars, variety and density of retail stores, density and access to educational units and parks, access to medical and service centers, and car ownership. Finally, by comparing the results of the ANOVA test with the regression analysis assessing the relationship between physical and non-physical factors (the same indicators in the same study areas) with travel behavior, the factors affecting travel behavior owing to different development patterns were identified. Factors such as car ownership, dependence and pro-liking for private cars, density and access to educational units and parks, access to medical and service centers, and variety and density of retail stores have been introduced as the factors affecting travel behavior due to the differences in development patterns. However, proximity to the public transportation station, accessibility preferences in choosing a place of residence, dependence, and pro-liking for other than a private car, having a certificate, number of children under five years old, and age have influenced on travel behavior regardless of the variation between neighborhoods (different physical development patterns).   Conclusion In In order to discover the factors affecting travel behavior due to the differences in patterns of physical development, this research has provided a more detailed analysis of the factors affecting travel behavior. It has achieved more accurate components than previous studies in this regard. Detailed analysis of studies related to travel behavior and finding the main components affecting it, considering the extent of variables and data, can pave the way for professionals in transportation planning and urban planning, in addition to providing detailed methods and criteria in the related literature.   Funding There is no funding support.   Authors’ Contribution Authors contributed equally to the conceptualization and writing of the article. All of the authors approved thecontent of the manuscript and agreed on all aspects of the work declaration of competing interest none.   Conflict of Interest Authors declared no conflict of interest.   Acknowledgments  We are grateful to all the scientific consultants of this paper.

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نویسندگان: 

Khademinia Shahin

اطلاعات دوره: 
  • سال: 

    2024
  • دوره: 

    1
  • شماره: 

    3
  • صفحات: 

    29-33
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    1
  • دانلود: 

    0
چکیده: 

Dy2Ce2O7 nanopowders were synthesized for the first time via solid-state reactions using Ce(NO3)3·6H2O and Dy2O3 as raw materials in a stoichiometric 1:1 Ce:Dy molar ratio. The synthesized materials were characterized by powder X-ray diffraction (PXRD). Structural analysis, performed using the FullProf program with profile matching and constant scale factors, confirmed a predominant cubic Dy2Ce2O7 structure with the Fd-3m space group. Field-emission scanning electron microscopy (FESEM) revealed that the Dy2Ce2O7 particles exhibited uniform spherical morphologies. Ultraviolet-visible (UV-Vis) spectroscopy demonstrated strong light absorption in the UV-visible region. The direct optical band gaps for samples S1, S2, S3, and S4 were determined to be 2.7 eV, 2.6 eV, 2.5 eV, and 2.4 eV, respectively.

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مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources
اطلاعات دوره: 
  • سال: 

    2015
  • دوره: 

    5
  • شماره: 

    3
  • صفحات: 

    199-208
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    374
  • دانلود: 

    0
چکیده: 

Contamination of soil was investigated in this study from the Tehran Oil refining Co. of Iran. Fifteen soil samples were collected at several points in the Azimabad, 15 km south of Tehran City, Iran. Samples were collected at depths of 0-30 cm. Control samp leswere prepared to determine background levels of soil contamination with petroleum hydrocarbons for comparison with contaminated sites. Total petroleum hydrocarbon (TPH) and poly-aromatic hydrocarbons (PAH) concentrations varied from 101334.0-101367.1 and 25321.1-25876.6 mg kg-1 respectively. The results elevated levels of TPH and PAH contents when compared with the control sample. Soil acidity (low pH of 5.3-5.9) and low electrical conductivity provided evidence of reduced metabolic activities on the affected site. Microbial growth rates for bacteria and fungi expressed as colony forming units were 2.62×109 and 4.14×106 CFU/g soil, respectively for the contaminated and 5.76×109 and 6.83×106 CFU/g soil, for the control treatments respectively. These drastic changes can have impact on the nutrient cycle and prevents the absorption of nutrients by plant root sand lead to a reduction in yield.

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بازدید 374

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نشریه: 

JOURNAL OF NANOSTRUCTURES

اطلاعات دوره: 
  • سال: 

    2025
  • دوره: 

    15
  • شماره: 

    3
  • صفحات: 

    1115-1120
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    9
  • دانلود: 

    0
چکیده: 

In this study, we fabricated CMC-PVP films doped with diverse amounts of SiO2 via casting method approach to examine their optical and structural characteristics. To create the samples, distilled water and a certain weight proportion of CMC and PVP polymers were first combined using a magnetic mixer and heated to 60°C for 1 h. The resulting homogenous solution was then poured into glass molds and allowed to evaporate. FTIR spectroscopy was used to examine the film structures and validate interactions between SiO2 and the CMC-PVP blend. According to optical analysis, transmittance values decreased as the proportion of SiO2 doping enhanced. Additionally, the refractive index, extinction coefficient, reflectance, absorbance, and absorption coefficient were enhanced. The optical energy gap values decreased with increasing SiO2 doping percentages, which were varied from 3.96 eV to 3.73 eV.

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اطلاعات دوره: 
  • سال: 

    1381
  • دوره: 

    26
  • شماره: 

    2
  • صفحات: 

    129-131
تعامل: 
  • استنادات: 

    3
  • بازدید: 

    3356
  • دانلود: 

    322
چکیده: 

سابقه و هدف: از آنجا که رشد کودکان و نوجوانان معیار مهمی برای ارزیابی وضعیت سلامت آنان می باشد، به منظور بررسی رشد جسمانی و سن بروز مراحل مختلف بلوغ، قد، وزن و سن ظهور نمو سینه ها، موهای ناحیه زهار و سن شروع اولین قاعدگی در دختران 11 تا 14 ساله در شیراز مورد بررسی قرار گرفت.مواد و روشها: در این مطالعه مقطعی، با روش نمونه گیری تصادفی چند مرحله ای حدود 10% از مدارس راهنمایی شیراز انتخاب و با استفاده از جداول اعداد تصادفی از هر 10 دختر 11 تا 14 ساله، یک نفر جهت بررسی انتخاب شدند.یافته ها: متوسط قد و وزن دختران در این مطالعه در مقایسه با استاندارد مرکز ملی آمارهای بهداشتی (NCHS) کمتر بود. متوسط سن شروع جوانه پستانها و رشد موهای ناحیه زهار بترتیب 1.8± 10.8 و 0.69± 11.5 سال بود. سن شروع اولین قاعدگی بطور متوسط 0.78 ±12.55 سالگی بود.نتیجه گیری و توصیه ها: با توجه به نتایج حاصله، بنظر می رسد رشد جسمانی دختران در مقطع سنی 11 تا 14 سال در شیراز کمتر از استانداردهای بین المللی است ولی سن شروع بلوغ و سیر آن قابل مقایسه با مقادیر آن در کشورهای دیگر است.

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نویسندگان: 

Jasim Ahmed Nsaif

نشریه: 

JOURNAL OF NANOSTRUCTURES

اطلاعات دوره: 
  • سال: 

    2025
  • دوره: 

    15
  • شماره: 

    3
  • صفحات: 

    1291-1302
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    9
  • دانلود: 

    0
چکیده: 

MnO thin films with different annealing temperatures were deposited via chemical spray pyrolysis. XRD analysis indicates that all films were polycrystalline with a dominant peak along the (111) plane. The average crystallite was increased via annealing temperature (400 to 500) oC. The dislocation density decreased from 50.33 to 42.18 nm when annealing temperature was raised from (400 to 500) oC. AFM was used to evaluate the morphology of the deposit films. As annealing temperature increased, the average particle size was measured to be between 77.6, 46.1, and 32.6 nm. SEM images show uniform spherical nano-grains, altering film morphology, which decreases with increasing temperature. The UV-Visible absorption spectra were utilized to obtain the optical parameters. Variations in film sensitivity to NO2 at different annealing temperatures highlight intricate relationships between temperature, film responsiveness, and NO2 concentration response. Oxidation induced by NO2 in MnO film (400, 450, and 500) °C results in elevated resistance due to electron drift, correlating with sensitivity, with the highest resistance observed at 500 °C.

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نویسنده: 

BABAZADEH MIRZA AGHA

اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    21
تعامل: 
  • بازدید: 

    164
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

NANOCOMPOSITES ARE A SPECIAL CLASS OF MATERIALS HAVING UNIQUE PHYSICAL PROPERTIES AND WIDE APPLICATION POTENTIAL IN DIVERSE AREAS. ENCAPSULATION OF INORGANIC NANOPARTICLES INSIDE THE SHELL OF CONDUCTING POLYMERS SUCH AS POLYPYRROLE (PPY) IS THE MOST POPULAR AND INTERESTING ASPECT OF NANOCOMPOSITES SYNTHESIS. …

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نویسنده: 

MANSOUR LAKOURAJ MOSLEM

اطلاعات دوره: 
  • سال: 

    2013
  • دوره: 

    20
تعامل: 
  • بازدید: 

    110
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

IN RECENT YEARS, RESEARCHES IN THE FIELD OF SUPRAMOLECULAR COMPOUNDS SUCH AS CALIXARENES AS SYNTHETIC RECEPTORS HAVE BEEN EXTENSIVELY DEVELOPED. IN ORDER TO ACHIEVE HIGHLY EFFECTIVE RECEPTORS, VARIOUS DERIVATIVES HAVE BEEN PREPARED BY INTRODUCING A VARIETY OF FUNCTIONAL GROUPS ON CALIXARENE...

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نویسندگان: 

KUMAR SANTOSH | Saha Abir

نشریه: 

IRANIAN POLYMER JOURNAL

اطلاعات دوره: 
  • سال: 

    2021
  • دوره: 

    30
  • شماره: 

    9
  • صفحات: 

    935-951
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    48
  • دانلود: 

    0
چکیده: 

The widespread uses of natural fibre/filler-reinforced composites are the recent advanced trend in the research field. This study investigates the effects of a relatively low concentration of graphene nanoplatelets (GNPs) in microwood particles-reinforced epoxy composites to enhance their physical, mechanical, thermal and fracture properties. The hybrid composites were prepared with hand layup techniques with different weight percentages of wood particles (0, 2. 5, 5, 7. 5 and 10) at a constant 0. 5% of GNPs. The surface modification of untreated and treated wood particles was analysed with X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy, showing that treated wood particles have a better interlocking bond with GNPs and epoxy matrix. The increments of 35. 55% tensile strength, 30. 64% flexural strength, 22. 98% hardness, 41. 67% impact strength, 16. 05% conductivity, 26. 71% fracture toughness and 74. 38% fracture energy were recorded with WGPC-5. 0 hybrid composites compared to WGPC-0. The maximum storage modulus (2. 4 GPa) and loss modulus (0. 26 GPa) also confirmed better interfacial bonding strength and stiffness for WGPC-5. 0 hybrid composites with the highest glass transition temperature of 92 °, C. The corrosion rate and water absorption properties were higher for the higher weight percent of wood particles. The morphological analysis confirmed that higher loading of wood particles (7. 5–, 10%) resulted in agglomeration, thus weak bonding of particles with epoxy matrix and therefore decrements in the properties were observed.

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