Improving participation in voluntary activities in Iran is important because increasing productivity among young people, given the country's young population, contributes to community sustainability. Therefore, a better understanding of volunteer motivation in Iranian youth is needed. The Volunteer Functions Inventory (VFI) for assessing volunteer motivations has good psychometric properties and is adapted to several languages, but no validated Iranian translation yet exists. The purpose of this study was to investigate the psychometric CHARACTERISTICS of voluntary functions inventory in members of Iranian Red Crescent Society. Sample size was 595 members of Youth Organization of Iranian Red Crescent Society from 31 provinces and 175 cities of Iran that were selected by multi-stage cluster sampling method and responded to voluntary functions inventory. Data were collected using a demographic sample and voluntary functions inventory (VFI). Confirmatory factor analysis using principal components method was used for data analysis. The results of the present study showed that the voluntary functions inventory had validity and reliability. Also, the factor structure showed that 29 items and 6 factors well assess people's attitudes to volunteering, and the structure of this inventory was well-fitted and confirmed all goodness of fit models. The present study provides the use of the Iranian translation of the Voluntary Functions Inventory (6 scales and 29 items) to assess volunteer motivation among young Iranian volunteers.

Nature has aesthetics of its own, what can provoke the human mind into better recognizing the concept of beauty via mental perception. As such, human mind can interact with the nonverbal expressions of nature only to better his/her primitive aesthetic knowledge and reach a more novel recognition of aestheticism via the practice of interpretative deduction. This article has been the result of a series of discussions and dialogues between the authors on the nature of aesthetic geotouring and exploring the NATURAL phenomena based on the Dialectical Method of Socrates and modelled after the Platonic dialogues. The outcome of this dialectic study brings to light the fact that touring in nature through providing the due opportunity for mental perception of aesthetic phenomena can provide a clearer definition of ‘beauty’ in its rich variety. Aesthetic search as such will culminate in forming a more illuminated mental concept of beauty in mind, what can influence human rationale for aesthetic judgment and enrich even more the texture of human aesthetic creation. Such aesthetico-interpretative endeavor might lead to a higher potential for creating more original works of literature and art and culminate in a better judgment about such aesthetic creations.

Background and Aim: Job enrichment is a method that has been used to increase employee satisfaction and work motivation. The Hackman and Oldham job CHARACTERISTICS model (1976) has served as the foundation for many job enrichment efforts. In particular, a considerable amount of research has been devoted to the study of the job CHARACTERISTICS-job satisfaction relations. Te purpose of this study was to statistically determine the relation between job CHARACTERISTICS and job satisfaction among employees of hospitals affiliated to Tehran University of Medical Sciences (TUMS) in 2007. Materials and Methods: This study was a cross-sectional one, including 6 TUMS-affiliated hospitals-Emam, Shariati, Baharlo, Ziaeian, Madaen and Azadi. The sample size was 400, consisting of 200 administrative employees (50%), 151 nurses (38%) and 49 physicians (12%). The random sampling and stratified proportional sampling methods were used to select the hospitals and interviewees, respectively. Two questionnaires were developed and used to identify job CHARACTERISTICS and job satisfaction: 1) job diagnostics surveys (JDS) and 2) Hertzberg's job satisfaction questionnaire. The reliability of the questionnaires was ascertained by test-retest using the Pearson correlation coefficient (r = 0.88). Linear-by-linear association and ordinal logistics regression analysis were used for analyzing the data gathered.Results:The relations between the Motivational Potential Score (MPS) and job CHARACTERISTICS (except for feedback) with job satisfaction were statistically significant (p<0.05). Task identity was the most effective determinant of job satisfaction. Conclusion: It appears that all the job CHARACTERISTICS (except feedback) are important determinants of job satisfaction of the hospital employees. Although the work environment is in need of restructuring, it is important to note, from a positive perspective, that the job CHARACTERISTICS discussed in this study are readily amenable to change job satisfaction at the organizational level.

The purpose of this study was to compare the technique of taking cephalometric radiographs in NATURAL Head Position (NHP) with slightly changing of the head in the direction of flexion and extension (In the amount of 5 degrees.) 40 Cephalometric head films of 20 cases, all of whom were dental students, were utilized in this study.The cephalograms were divided into two groups. At first lateral cephalometric radiographs in NHP were taken from all of the cases, then another radiograph was taken in extended head position (the head changed 5 degrees upward from NHP position) from cases of group one, and in flexion head position (the head changed 5 degrees downward from NHP position) from cases of the second group. In this study 24 landmarks and 36 variable were evaluated.All radiographs were twice and data captured with a digitizer and computer. Evaluation of the results, which are shown in table I, revealed that 9 of the variable among 36 showed significant differences compared to NHP position, and two of the variable was common between the two groups. However, 27 of the measurments didn't show any significant differences. Considering the fact that one fourth of the landmark measurments which were evaluated in this study showed significant differences during slight extension or flexion of head, taking of lateral cephalometric headfilms in NHP is recommended specially when they are to be used in serial studies or ar taken for research purpose.However, because other 27 measurment (which comprise three fourth of all the measurments) showed no significant changes, we concluded that lateral cephlograms which are not taken in NHP may be used for diagnostic and treatment planning purpose.

Evaluating the cutting rate (CR) of stones is important in the cost estimation and the planning of the stone processing plants. This research used regression models to estimate the stones’ CR based on their physico-mechanical CHARACTERISTICS. Stone processing factories in Mahallat City (Markazi province, Iran) were visited, and the CR of diamond circular saws was recorded on six different travertine stones. Next, the stone block samples were collected from the quarries for laboratory tests. Stones’ porosity (n), uniaxial compressive strength (UCS), and Schmidt hammer hardness (SH) were determined in the laboratory as their physico-mechanical CHARACTERISTICS. Correlation relationships of CR with physico-mechanical CHARACTERISTICS were evaluated using simple and multiple regression analyses, and estimator models were developed. Results showed that multiple regression models are more reliable than simple regression for estimating the stones’ CR. The validity of the developed multiple regression models was verified with the published data of one researcher. The findings indicated that these models are accurate enough for estimating the CR of stones. Consequently, the multiple regression models provide practical advantages for estimating the CR and save time and cost during the planning and design of the stone processing factories.

Compatibility is a serious problem in silica-added NATURAL rubber (NR) because of the difference in the polarities of silica and NR. Thus, a coupling agent, such as silane, or a compatibilizer must be incorporated. In this work, amine-functionalized NR was synthesized by an in situ epoxidation process using performic acid and later modified with hexamethylene diamine (HMDA) by a ring-opening reaction. The effects of amine-modified epoxidized NR (ENR-HMDA) content on the cure CHARACTERISTICS, physical and mechanical properties of various NR blends (NR/ENR-HMDA) without filler were studied. ENR-HMDA enhanced the vulcanization process. The maximum torque of compounds increased with the corporation of ENR-HMDA and scorch time and cure time decreased. The cure rate index of NR/ENR-HMDA increased by 98%. All vulcanized rubber blends showed the strain-induced crystallization at high extension. Mechanical properties and crosslink density of the blends were higher than those of NR and NR incorporated with unmodified ENR. Tensile strength was 61% and 43% higher than that for NR and NR/ENR, respectively. The NR/ENR-HMDA blends showed a single Tg that indicated the miscibility of both components. The developed ENR-HMDA compound can be used to improve the compatibility of NR and fillers which would enable the fabrication of a wide range of rubber products.

Strict emission regulations together with reducing fossil fuels resources lead to more attention on new combustion strategies and alternative fuels such as biodiesel which is renewable, environmentally friendly and more cost-effective than other fuels. In this study, CONVERGE CFD software coupling with chemical kinetics mechanism is used to numerically investigation of NATURAL gas (NG)/biodiesel dual fuel engine. The discussed biodiesel consists of 25% methyl decanoate (MD), 25% methyl-9-decanoate (MD9D) and 50% diesel. A comparative study of NG/diesel and NG/biodiesel fueled cases is performed to highlight the combustion CHARACTERISTICS of biodiesel. For all simulated cases, it is supposed that 5% of energy is supplied by high reactive fuel (i.e., Diesel or Biodiesel) and 95% is coming with low reactive fuel (i.e., NATURAL Gas). Results revealed that in full load condition, using biodiesel/NG led to 86% lower carbon monoxide (CO) and 91% unburned hydrocarbons (UHC). On the other hand, peak pressure and maximum in-cylinder temperature increased 5% and 83 K, respectively which led to 0.6% efficiency improvement. according to the results of different injection timing, when it was advanced from -4 to -20 crank angle degree after top dead center (CAD ATDC) for biodiesel/NG and diesel/NG, the indicated mean effective pressure (IMEP) and gross thermal efficiency (GTE) reached at their peaks 18.3 bar and 48.2% at -12 CAD ATDC, 18.05 bar and 47.7% at -8 CAD ATDC respectively.

The aim of this study was to investigate the effect of using portulaca oleracea as a source of plant antioxidants for feeding fattening male lambs, on carcass traits, meat quality, and oxidative stability. Twenty-one male lambs with an average weight of 24±1.5 kg and 150±15 days old were fed with one of the experimental rations included a diet without portulaca oleracea as control, a diet containing 7.5%, and a diet containing 15% portulaca oleracea, for 84 days. The muscle (Longissimus dorsi) samplewas used to determine pH, chemical composition, colorimetric properties, and oxidative stability of meat. Meat lipid oxidation was determined after 1, 7, and 30 days of refrigerated storage using thiobarbituric acid (TBARS). The use of portulaca oleracea in diets improved meat color CHARACTERISTICS such as L, chroma, and Hue. The highest ash concentration and the lowest meat moisture were observed in the treatment of 15% portulaca oleracea (P<0.05). Meat pH was the lowest in the first hour after slaughter but did not differ at 24 h. Compared to the control, in both treatment groups feeding the lambs with portulaca significantly reduced the concentration of Malondialdehyde in the meat of the lambs and increased the meat oxidative stability (P<0.05). The results of this experiment showed that feeding portulaca oleracea by improving properties such as color and increasing the meat oxidative stability improves meat quality, which may have lead to an increase in its nutritional value in terms of human health.