A Comprehensive Method For Coordinating Distributed Energy Resources In A Power Distribution System

Utilities, faced with increasingly limited resources, strive to maintain high levels of reliability in energy delivery by adopting improved methodologies in planning, operation, construction and maintenance. On the other hand, driven by steady research and development and increase in sales volume, the cost of deploying PV systems has been in constant decline since their first introduction to the market. The increased level of penetration of distributed energy resources in power distribution infrastructure presents various benefits such as loss reduction, resilience against cascading failures and access to more diversified resources. However, serious challenges and risks must be addressed to ensure continuity and reliability of service. By integrating necessary communication and control infrastructure into the distribution system, to develop a practically coordinated system of distributed resources, controllable load/generation centers will be developed which provide substantial flexibility for the operation of the distribution system. On the other hand, such a complex distributed system is prone to instability and black outs due to lack of a major infinite supply and other unpredicted variations in load and generation, which must be addressed. To devise a comprehensive method for coordination between Distributed Energy Resources in order to achieve a collective goal, is the key point to provide a fully functional and reliable power distribution system incorporating distributed energy resources. A road map to develop such comprehensive coordination system is explained and supporting scenarios and their associated simulation results are then elaborated. The proposed road map describes necessary steps to build a comprehensive solution for coordination between multiple agents in a microgrid or distribution feeder.\u2

Bioleaching of Low Grade Uranium Ore of Saghand Mine

ABSTRACT: This study deals with bioleaching of the low grade uranium ore of Saghand mine in Iran using a mixed culture of mesophilic bacteria (Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans). Experiments were carried out in shaking flask examining the effect of temperature, initial ferrous ion concentration, pulp density and particle size. Variations of pH, Eh, ferrous ion concentration, cells growth and uranium extraction were monitored. The highest rates of leaching and extraction were obtained at 35ºC, 2.5% (w/v) pulp density, 4 g/l ferrous ion and -106µm particle size

The Effects of Knee Orthosis with Two Degrees of Freedom Joint Design on Gait and Sit-to-Stand Task in Patients with Medial Knee Osteoarthritis

Objectives: Knee bracing as a conservative treatment option for patients with medial knee osteoarthritis (KOA) is of great interest to health practitioners and patients alike. Optimal orthotic knee joint structure is essential to achieve biomechanical and clinical effectiveness. Therefore, this study aimed to identify the effects of a knee orthosis with a new two-degrees-of-freedom (DOF) joint design on selected gait parameters and in a sit-to-stand task in patients with mild-to-moderate medial KOA. Methods: This study was conducted both at the Physical Medicine and Rehabilitation Clinic in Shahid Modarres Academic Hospital and the Biomechanical Laboratory of Rehabilitation Faculty of Iran University of medical Sciences in Tehran, Iran from September 2015 to October 2017. The gait performance of 16 patients was assessed without an orthosis, using a common one-DOF (DOF) knee orthosis and using the same knee orthosis with a two-DOF orthotic joint design. The interactive shearing force between limb and brace in the shell area during a sit-to-stand test was also identified. Repeated measures analysis of variance was used to analyse the data. Results: Compared with walking with no orthosis, both orthosis conditions reduced the external knee adduction moment significantly (P ≤0.05). A significant increase between the one-DOF and two-DOF conditions in terms of walking speed (P = 0.041 and P = 0.009, respectively) and stride length (P = 0.028 and P = 0.038, respectively) was observed. In a sit-to-stand test, wearing the orthosis significantly decreased knee transverse plane range of motion (P ≤0.05). There was a 41.31 ± 8.34 Newtons reduction in knee flexion constraint force. Conclusion: The two-DOF knee orthosis was more comfortable compared to the one-DOF knee orthosis during deep knee flexion. Otherwise, the one- DOF- and two-DOF-braces performed similarly. Keywords: Knee Osteoarthritis; Orthosis; Braces; Gait Analysis; Rotations; Kinematics; Kinetics; Patient Comfort

Design, Implementation and Testing of a Novel Prototype Orthotic Knee Joint with Two Degrees of Freedom in a Patient with Medial Knee Osteoarthritis

Knee braces are a conservative treatment option for patients with knee osteoarthritis (KOA). However, no commercially available orthotic knee joint currently reflects natural knee movements. A prototype orthotic knee joint with two degrees of freedom (DOF) in the sagittal and transverse planes was developed to more closely simulate the natural motion of the knee joint. The prototype was tested on a male subject with medial KOA during a sit-to-stand task. The efficacy of the transverse plane DOF was assessed by comparing the limb-orthosis interaction force when the transverse plane was locked to mimic a one-DOF setting versus when it was unlocked. Unlocking the transverse plane eliminated the 45-Newton shearing force produced with the one-DOF setting at wide angles of flexion. The two-DOF orthotic knee joint prototype demonstrated greater conformity to natural knee movements, allowing the wearer to better tolerate bracing-related difficulties.  Keywords: Knee Joint; Knee Osteoarthritis; Orthotic Devices; Braces; Rotation; Movement; Materials Testing

Risk Factors of Post-Partum Depression Among Pregnant Women Attending Primary Health Centers, Mazandaran Province, Iran

Post-partum depression (PPD) is the most common psychological complication of childbirth. Disagreement about the causes of PPD is considerable and currently its etiology is still not fully understood. The aim of this study is to determine the contribution of demographic, sociological, psychological, obstetric and gynecological, cultural and hormone-related risk factors to developing PPD in pregnant women in Mazandaran province, Iran. This is the first ever study of its kind in the country. In this prospective cohort study, 2,279 eligible pregnant women 16 to 45 years of age in their third trimester who attended Primary Health Centers were screened for depression using the Iranian version of Edinburgh Postnatal Depression Scale (EPDS). Of those, 1801 pregnant mothers were found to be free from depression and were followed up 2, 8 and 12 weeks post-partum. The potential risk factors were assessed using 15 standardardized questionnaires. Data were analyzed using Chi-square and simple and multiple logistic regression. Out of 2,279 participants, 478 (21.0%) of those had EPDS score >12 during third trimester of pregnancy. Among 1,801 pregnant mothers who did not have depression during third trimester pregnancy, the cumulative incidence rates of depression occurring in post-partum period were 6.9% (120/1,739), 4.6% (69/1,509) and 4.8% (65/1,357) at 2, 8 and 12 weeks post-partum, respectively. In the multiple logistic regression model, the factors predictive of PPD during the twelve weeks after birth after excluding mothers who were depressed in third trimester of pregnancy were a) depression during the first and second trimester of pregnancy (OR= 2.55, 95% CI=1.59-4.1), b) having a psychiatric disorder in pregnancy based on General Health Questionnaire (GHQ) (OR= 1.08, 95% CI=1.06-1.11), c) gestational diabetes (OR=2.93, 95% CI=1.46-5.88), d) recurrent urinary infection during pregnancy (OR=2.25, 95% CI=1.44-3.52), e) unwanted pregnancy (OR= 2.5, 95% CI= 1.69-3.7), and f) low household income (OR=3.57, 95% CI=1.49-8.5). On the other hand, the risk of post-partum depression was decreased for mothers with elevated age (OR=0.88, 95% CI= 0.84-0.92) and for mothers who reported high self efficacy about mothering based on Parental Expectation Survey (OR=0.7, 95% CI= 0.62-0.78). The findings of this study indicated that a high incidence of post-partum depression was identified in Iranian women, making PPD one of the major public health problems. These findings indicate that several domains of risk factors including demographic, psychological, sociological and obstetric factors put mothers at risk for post-partum depression. Antenatal depressive symptoms were shown to be a key antenatal risk factor for postnatal depression. Culture element was not a risk factor for developing PPD in this traditional society. Key Words: Post-partum depression, risk factors, longitudinal, cohort, Ira

Study of Hierarchical Relationship Model between the prosecution service and the police in the Criminal Process

Relations between the prosecution service and the police follow different models in accordance with the ruling system- Accusatorial or Inquisitorial-. This paper uses the strategy of logical analysis and library method to introduce hierarchical communication model that is in accordance with inquisitorial system. This relationship is contrary to the model in accusatorial system, which is regulated by a kind of network interaction. The components of the hierarchy model include:1- broad powers of the prosecutor and governance over the police, 2- limited police powers and 3- obedience of the prosecutor and vertical relations between the prosecutor and the police. This model has the benefits such as coherent organization, certainty and equality in law enforcement, and suffers from damage such as inefficiency in monitoring, ignoring human dimensions, costly, and inflexible relationships. It seems that it is not necessary to endure these damage in the police and prosecution service relationships, because, based on the many other successful experiences of other countries in the world, hierarchical model governing prosecution service and police can be improved by making non-fundamental change. Since the model of Prosecutor's office and police relations in Iran is hierarchical, this paper can improve these relations