Online control of combine reel height in presence of farm roughness using an on-off controller

Adjusting the harvesting combine reel height in presence of the farm rough surface reduces the harvest losses, prevents possible damage to the headland and increases gravel harvest. Regarding the importance of the issue, in this study, the dynamics of the reel height control system of the John Deere1055 combine was modeled and the controllability and observability of the obtained transfer function is determined in state space. After that, with the aim of cutting the stem from a suitable point, an on-off controller is designed to keep the reel height from the ground in a permitted range. At this stage, a reduced model system is used as an approximated system to design a controller. The designed controller is simulated in MATLAB. In this simulation, the roughness of the ground was considered as the control loop noise with the normal probability distribution function. The results confirm that the reel height change is kept in the specified range against the farm roughness. The laboratory sample was also constructed using an independent excitation circuit DC motor, an optical distance sensor, and a micro controller. The experimental test shows that the height control system responses to changes in surface height at an appropriate speed without any oscillation in range

Investigation of reactivity changes due to flooding the irradiation sites of the MNSR reactor using the MCNP code and comparison with experimental results

In this work, the Isfahan Miniature Neutron Source Reactor (MNSR ) has been simulated using the MCNP code, and reactivity worth of flooding the inner irradiation sites of this reactor in an accident has been calculated. Also, by inserting polyethylene capsules containing water inside the inner irradiation sites, reactivity changes of this reactor in same such accident have been measured, the results of which are in good agreements with the calculated results. In this work, the reactivity worth due to flooding one inner irradiation site is 0.53mk , and reactivity worth due to flooding of the whole 5 inner irradiation sites is 2.61 mk

Contact dermatitis in cement workers in Isfahan

<b>BACKGROUND: </b> Due to recent industrialization and inadequately protected workers or in other words poor supervision on constructive workers habits in our large city of Isfahan cement contact dermatitis is relatively high especially among cement factory workers and constructive personnel. <b> PURPOSES: </b> To investigate the prevalence rate of cement contact dermatitis in cement factory workers in Isfahan. <b> METHODS: </b> A case-control clinical study was carried out by randomly selecing 150 factory workders and 150 official clerks in a cement factory in Isfahan in 2001. After a complete physical examination, data was recorded in observational checklists. <b> FINDINGS: </b> The percentages of contact dermatitis prevalences in the first and the second groups were 22&#x0025; and 5.3&#x0025; respectively. About 60&#x0025; of cement workers with contact dermatitis were between 30-40 years of age. There was a direct relationship with age in both groups of the workers. In the high-exposure group, the hand eczema along was 70&#x0025; but in the other group the percentage of involvement was the same in exposed and unexposed anatomical areas. <b> CONCLUSIONS: </b> There was a direct relationship between occurrence and the severity of involvement and duration of contact in the first group. Cent percent of cement workers had contact dermatitis after 10 or less years, but the percentage among the other group was 35&#x0025;. <b> LIMITATION: </b> Irritant contact dermatitis to cement has not been detected

Heritage Contests: What Can We Learn from Social Movements?

© 2018 Informa UK Limited, trading as Taylor & Francis Group. While contests and conflicts are well recognized in heritage research, analysis of the specific circumstances and dilemmas that individuals and groups face when pursuing heritage goals and partaking in heritage contests can benefit from further methodological work. This paper presents a case and method for incorporating concepts from an emerging interactionist perspective on social movements into heritage research in order to better conceptualize and analyze the interactions and processes through which collective identity and heritage is co-produced. We examine the political and interpretive processes at the heart of heritage research, consider areas in which the language and concepts of social movements addresses existing gaps and disagreements, and identify a set of questions that will open new perspectives on heritage movements and contests. We apply these questions to a heritage contest over the World Heritage site of Pasargadae in Iran, emphasizing how heritage activists advanced their perspectives and claims, eventually leading to the incorporation of Iran’s pre-Islamic heritage within the official Islamic republic discourse

Picturing Pasargadae: Visual Representation and the Ambiguities of Heritage in Iran

This paper probes the relationship between visual representations and visitation practices at Pasargadae, a UNESCO World Heritage site in southern Iran. Presenting a systematic analysis of publicly available online images of Pasargadae, the paper examines the complex relationship between the place and its visual representations. Through analysis, the paper elaborates on a sense of intimacy that, while grounding Pasargadae, is also a potential common ground in pre-Islamic heritage in which the Iranian state and society could at once meet and contest versions of identity. Examining this relationship facilitates reflections into both heritage and the peculiarities of its visual representation in the Iranian context