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Aims: Manual tasks and load carrying and handling are the most important tasks in a sofa making workshop. Evaluation of these types of tasks is very important for identifying the health risks to which workers are exposed. The aim of this study was the ergonomic evaluation of occupational tasks in a sofa making workshop based on KIM and presentation of corrective actions.
Instruments and Methods: The present descriptive cross-sectional study was conducted in a sofa making workshop in Ardabil in 2017. All tasks of the sofa making workers (n=22) were examined, among which 7 main tasks were identified. The identified tasks were analyzed, using KLM-MHO and KLM-LHC methods. Manual tasks and load lifting and carrying tasks were evaluated, scored, and checked out, using EXCELL 2010.
Findings: Among the tasks examined, the tasks of woodcarving, preparation for coloring, and sofa dressing showed the highest final score (Risk Grade 4), followed by jointing wood parts with glue and coloring (Risk Grade 3). Most items with high workload were related to grips status, repetitive movement in the hand-finger area, position and repetitive movements of the joints at the end of motion range, and curved forward trunk posture.
Conclusion: In carving, preparation for coloring, and dressing tasks, the amount of workload is high. In jointing wood parts with glue and coloring tasks, the amount of workload increases dramatically. And, in designing layout on wood and cutting tasks, the amount of load increases.

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Aims: Musculoskeletal disorders are the most common work-related complications in industrial environments. Inappropriate body working postures are considered as one of the most important risk factors for musculoskeletal disorders. The aim of this study was the ergonomic assessment of body working postures among the employees of a car services workshop, using OWAS technique.
Instruments and Methods: This study was a descriptive cross sectional study conducted in 2017 in a car services workshop selected through simple random sampling method. The study sample was one of the representatives of Iran Khodro Company in Ahwaz. Based on the study sample, 960 different body postures were recorded. Using OWAS method as a posture assessment method, each of the occupations was photographed for 40 minutes at 30 second intervals. The data were evaluated by Excel 2012 software and the photographs were evaluated by OWAS method.
Findings: Workers' work environment was ergonomically appropriate. Generally, 95.0% of the working postures were related to Level 1, indicating that most of the workstations did not need to be modified. The repetitive movements had the highest body working postures score.
Conclusion: Just in the case of car repairers, there was a need for redesigning the workstation. In other cases, the tasks of repairing, coloring, and pressing were related to Code 1.

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The aporia of causal necessity can be defined by looking at the dilemma of (1) the permanent, logical, and metaphysical concomitance of necessity and causation, or (2) the negation of one without the negation of the other, and in fact, the denial of the permanent concomitance of necessity and causation. This Aristotelian doctrine that everything has a cause cannot necessarily be a logical and philosophical result of determinism, the negation of the possibility of the future, and the collapse of potentiality into actuality. Necessity is the description of the causality that occurred in the context of the current reality of the present and the past, not the causality that occurs in the future. It is possible not to consider this meaning of necessity as requiring determinism and the principle of causality. In fact, the operator and the logical and metaphysical modality of causality is the actual reality of necessity, which is not always coextensive with determinism. By ignoring the final cause, Democritus reduces all the actions of nature to necessity. The reductionism resulting from the denial of the teleology of the world is a characteristic feature of Democritean mechanical necessitism.

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Locus of Control (LOC) is a psychological construct that deals with people's perception of the extent to which they are in control of what happens to them and it has been proved to play a crucial role in one’s success or failure in various aspects of life. Although LOC is by no means a stable construct, the current body of research had a linear one-shot cause-effect perspective towards it. Hence, framed within a Complex Dynamic Systems Theory (CDST), this case study tries to revisit Iranian university students' LOC through the application of Dynamic Ensemble (DE). To this end, five students from Bojnord university who were attending their General English (GE) course participated in this study. The data collection was done through semi-structured interviews, task-motometers, students' journals, and participant classroom observations during seven classroom sessions. The collected data were qualitatively content analyzed by the application of MaxQDA software. Having analyzed the collected data, several macro-systemic, micro-systemic, and contextual factors were identified as being influential on the students' internality or externality of LOC. Considering the fact that many scholars believe internal LOC is the healthier attribute, this study focuses on the factors which can help teachers lead their students to become internalizers.
 
1. Introduction
Locus of Control (LOC) is a psychological construct, which refers to peoples’ beliefs about the control they have over the situations and experiences affecting their lives (Rotter, 1966). Rotter (1966) introduced a model for LOC with two dimensions namely, internal and external LOC. He asserted internalizers ascribe the reasons for their success or failure to some internal factors such as their own attempts, abilities, activities, and behaviors. In contrast, externalizers think that some external factors like fate, powerful others, and chance or luck, that is out of their control, affect their fate and achievements.
LOC is a multidimensional psychological construct and it has a dynamic nature, which means that it changes over different situations (Ghonsooly & Elahi Shirvan, 2011). This dynamicity underscores the nonlinearity of changes, which means there are almost no predictable cause-effect relations in the systems behavior (Larsen-Freeman, 2016; Waninge et al., 2014).  Thus, in order to get a better and deeper understanding of LOC in interaction with its surrounding environment, this study focuses on the contextual and intra/interpersonal factors which can help a student improve their state of internal LOC.
Research question
How can the underlying variables of  students’ LOC in a course of General English be defined in light of Complex Dynamic System Theory (CDST) through the application of Dynamic Ensemble ?
Dynamic ensemble
Hiver and Al-Hoorie (2016) applied the underlying tenets of CDST in a research study to propose the dynamic ensemble, which is a list of complexity considerations that tries to make CDST easily applicable in the field of applied linguistic research.
2. Methodology
The purpose of this study was to delve deep into the procedural, individual and contextual factors; therefore, in order to allow for the intensive concentration and observation in part of the researchers a limit of five Iranian university students who were attending their GE course (two males and three females) was decided. One of the main aims of this study is to provide evidence for the dynamic nature of LOC . Thus, deviant or extreme case sampling strategy (Dornyei, 2007) was employed in order to select our participants from the highest and lowest scoring students on a specific version of the Internal Control Index (Duttweiler, 1984) which was translated into Persian and validated for the Iranian context by Ghonsooly and Elahi (2010).
On the basis of the main purpose and the qualitative nature of this study, different types of data collection  including interviews, observation, journals, and task-motometers were applied by the researchers to ensure the data collection is done thoroughly and every environmental aspects of the participants were taken into account.
 
3. Results
The findings of this study revealed the dynamic and multidimensional nature of LOC which means it changes over and over under the influence of different situations and circumstances and in relation with some other factors. This finding is in accordance with what Larsen-Freeman (2016) asserted in her seminal paper about non-linearity and complexity of students’ behavior in classroom studies. In fact, analyzing the collected data indicated that during the process of language learning, the students experienced fluctuations in their LOC and these fluctuations occur even during a single class under the influence of different intra/interpersonal or environmental factors which is in line with what Waninge et al. (2014) introduced as the dynamic nature of psychological constructs. The dynamic nature of students’ LOC underscores the nonergodicity of human’s behavior (Lowie &Verspoor, 2019). Application of dynamic ensemble revealed the fact that the student’s LOC was under the influence of many factors.
At the micro-structural considerations level, learner’s beliefs and motivations, their positive and negative attitudes, and the students’ learning expectations affected the students’ internality and externality of LOC. It was recognized that the motivational factors and students’ positive attitudes toward the effectiveness of learning English reinforced students’ internal LOC. Learning English seemed to play an important role in helping the students reach their future goals such as traveling abroad or being accepted in higher level of educational degrees. These sorts of motivating factors helped the students try more and be more self-reliant and it helped them believe today’s struggles would positively affect their future.
In addition, the students’ beliefs about the teacher’s responsibility were among the factors which in most cases led them towards being externalizers. The source of this effect was in the teaching expectations that the students had but they received little or no answer to these expectations on the part of their teacher. The students’ increased knowledge was another motivating factor which helped the students to rely on themselves and consequently become internalizers. This finding is in accordance with what Peek (2016) highlights about the positive effects of students’ knowledge and learning skills on their internal LOC.
At the micro-structural considerations level, cognitive, linguistic, and affective factors influenced the students’ LOC differently. It was indicated that the students with rich background knowledge were more internalizers. However, in some occasions the knowledgeable students preferred to be silent to immune themselves from their classmates’ laughter and judgements.  Furthermore, topical interest in some of the tasks was another reason for making the students internalizer. Also, speaking in front of the others, being laughed at, and negative judgment by teachers as well as classmates were among the affective factors making students’ more externalizers.
 We also found that curriculum design and course assessment were sometimes planned in a way that hurt students’ full concentration on the process of learning (e.g., being tired due to  participation in hard practical classes just before attending their English language classes) and led them towards being externalizers.
 
 

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In this article, the linear quadratic regulator method (LQR) for voltage control of a linear time-varying model of a robot is used to design an on line adaptive optimal stable controller to trace the robot arm path. Normally, off line solving of Riccati differential equations in backward with final conditions for linear time-varying system or converting the Riccati differential equation to algebraic one in linear time-invariant system is inevitable in LQR. However, in this paper, the differential Riccati equations are considered as the adaptation laws along with a voltage control strategy to be solved on line in forward method with initial conditions. Choosing a proper Lyapunov function guarantees the asymptotic stability of the tracking. Furthermore, parametric model uncertainties such as mass parameter variation and external disturbances which affect the dynamics of the model, are also taken into account. Simulation results show the energy used by dc motors of the voltage optimal control strategy is less than that of the torque control strategy and as well as the classical PID one. The superior performance of the voltage optimal control over torque control strategy is also shown in presence of disturbance.

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This study investigated the effect of CarboxyMethyl Cellulose (CMC), tragacanth, and Saalab hydrocolloids in two concentrations (0.3 and 0.7%) and different frying media (Refined Canola Oil (RCO), RCO+1% Bene Kernel Oil (BKO), and RCO+1 mg L^-1 UnSaponifiable Matter (USM) of BKO on acrylamide formation in fried potato slices. The hydrocolloid coatings significantly reduced acrylamide formation in potatoes fried in all oils (P< 0.05). Increasing the hydrocolloid coating concentration from 0.3 to 0.7% produced no effective inhibition of acrylamide (P> 0.05). The 0.7% CMC solution was identified as the most promising inhibitor of acrylamide formation in RCO oil, with a 62.9% reduction in acrylamide content. The addition of BKO or USM to RCO led to noticeable reduction in the acrylamide level in fried potato slices. The findings suggest that a 0.7% CMC solution and RCO+USM are promising inhibitors of acrylamide formation in fried potato product.

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Vegetables have a short shelf life, and because they are eaten fresh, it is necessary to use healthy and natural methods to increase their shelf life. The present study has investigated the effect of active packaging containing the active ingredient of thymol on the color and pH measurements, microbial evaluation, total mold and yeast count, and the sensory properties of seasonal salad during six-day storage refrigerator temperature. For this purpose, seasonal salads were packed with oriented polypropylene (OPP) and low-density polyethylene (LDPE) films immersed in thymol essential oil for 1, 2, and 3 days. Results show that season salads packed with OPP and LDPE films immersed in thymol essential oil for three days had higher pH and lower mold and yeast count than control and other treatments. The mold and yeast count were significantly lower (p < 0.05) in a sample packed with OPP films containing essential oil compared to the LDPE/ thymol essential oil. The L* and a*values decreased during storage time. The L* and -a * indices of season salads were lower in OPP and LDPE films immersed in thymol essential oil for three days than the neat and other groups. Sensory evaluation showed that immersion in thymol essential oil improved sensory attributes (p <0.05).  The coated films, especially OPP, improved the color, reduced the number of mold and yeast, increased the shelf life, and improved the sensory attributes of seasonal salads. Therefore, films treated with thymol essential oil can act as active packaging.

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