Monitoring and evaluation of transformers are essential to prevent their insulation failure. In this paper, the use of 2-furan-carboxaldehyde (2-FAL) and methanol (MeOH) concentrations as the main products of paper insulation degradation, and insulation condition markers, has been studied. In order to study the degradation process and production of degradation products, the thermal aging process of the transformer insulation system was implemented in laboratory conditions. The results of laboratory studies show that in the early stages of degradation the amount of MeOH is significant compared to 2-FAL. Also, the estimation of the degree of polymerization (DP) in the early stages of degradation (DP>800) through MeOH concentration and with decreasing DP (DP <800) through 2-FAL concentration is closer to the real value. The results of studies performed on 35 distribution transformers confirm the production of significant amounts of MeOH in the early stages of degradation. Also, the estimated DP values for the studied transformers were obtained through 2-FAL and MeOH concentration. The results show that estimating the amount of DP through MeOH concentration is associated with a probability of error of about 9% compared to estimating DP through 2-FAL concentration.

A Comparative study of the absorbency properties of different brands of endodontic paper points (Diadent, Roeko, Ariadent, Ali) has been conducted. Four brands of standardized absorbent paper points were tested. 30 paper points of each brand (size 40) were selected randomly and each dry paper points were weighted using a laboratory balance with 10-5 gr accuracy. A length of 16mm from the tip was then lowered in normal saline for 5 seconds. The moist paper points were weighted again and the differences between two measurements were taken.In the second method we used lower premolar human teeth which were prepared endodonticaly (MAF=40 & Flaring = 60).Before drying with each paper points, the tooth canal was washed with 10cc of normal saline. And the difference between dry weight and postimmersion weight were measured.In both methods Diadent shows the highest absorbency properties then Roeko and Airadent & Ali but were not statisticaly significant.According to intracanal method Diadent has absorbed 965.333xI0-5gr of normal sa line & Ariadent 855.8´10-5 gr & Roeko 845.667´10-5 gr Ali 443.8´10-5gr.According to other method Diadent has absorbed 972.8´I0-5gr of normal saline & Roeko 866.4´I0-5gr & Ariadent 588.133´I0-5gr.

Statistical Shape Models are used to interpret shapes. They include mean and variance of corresponding points of training shapes. One of the most important challenges in building statistical shape models is to establish correct correspondences among landmarks in a training set. In this paper, the non-rigid CPD (Coherent Point Drift) method is used to find correct correspondences among points. This method uses both Deterministic Annealing and a non-rigid scheme to register two shapes simultaneously. Then, the statistical shape model is built using a rigid transformation. The proposed method is evaluated using Compactness, Generalization ability and Specificity measures. The built model is compared to models created using the ICP (Iterative Closest Point), TPS-RPM (Thin Plate Spline – Robust Point Matching) and MDL (Minimum Descreption Length) methods by these metrics. The results show that the proposed method performs like the MDL regarding Specificity measure (0.21±0.06). The Compactness and Generalization ability measures of the proposed method are very similar to those for the MDL method. The run-time of our proposed method is about 68 seconds which is faster than non-rigid TPS-RPM and MDL approaches (390 and 3600 seconds respectively). Our results are superior to the ICP and TPS-RPM algorithms.

Non-cooperative intelligent control agents (ICAs) with dedicated cost functions, can lead the system to poor performance and in some cases, closed-loop instability. A robust solution to this challenge is to place the ICAs at the feedback Nash equilibrium point (FNEP) of the differential game between them. This paper introduces the designation of a robust decentralized infinite horizon LQR control system based on the FNEP for a linear time-invariant system. For this purpose, two control strategies are defined. The first one is a centralized infinite horizon LQR (CIHLQR) problem (i.e. a supervisory problem), and the second one is a decentralized control problem (i.e. an infinite horizon linear-quadratic differential game). Then, while examining the optimal solution of each of the above strategies on the performance of the other, the necessary and sufficient conditions for the equivalence of the two problems are presented. In the absence of the conditions, by using the least-squares error criterion, an approximated CIHLQR controller is presented. It is shown that the theorems could be extended from a two-agent control system to a multi-agent system. Finally, the results are evaluated using the simulation results of a Two-Area non-reheat power system.

Background: Finding a reliable diagnostic method for brucellosis is the most challengeable problem. In this study we determined the optimal diagnostic cut-off point for ELISA test.Methods: We gathered 56 confirmed cases of brucellosis. Furthermore blood samples from 126 controls including 73 healthy controls and 53 without brucellosis febrile patients were collected. In all of the cases and controls ELISA Ig G and ELISA Ig M levels were measured and compared with each other by Box plot graph and the Receiver Operating Characteristic (ROC) curve. The sensitivity and specificity of ELISA Ig G and Ig M were fixed in different cut-off values and Ig G and Ig M levels yielding maximal sensitivity plus specificity were selected for determination of optimal cut-off point.Results: The nineteen patients had positive blood cultures for Brucella melitensis. The standard agglutination test results were 1/160 or more in 54 patients. The Box plot graph indicated a high degree of dispersion for Ig G and Ig M data in patients with brucellosis compared with febrile patients without brucellosis and healthy controls. We observed partial overlap for Ig M data (not for Ig G) between cases and controls. The area under ROC curve for discrimination of cases and healthy controls was more for Ig G than Ig M.Conclusions: The ELISA Ig G is more reliable test than ELISA Ig M in diagnosis of brucellosis. Using cut-off of 10 IU/ml and 50 IU/ml have the most sensitivity (92.9%) and specificity (100%) for ELISA Ig G test, respectively. 

In this paper, we improve some recent coupled fixed point results for single-valued operators in the framework of ordered b-metric spaces established by Bota et al. [M-F. Bota, A. Petrusel, G. Petrusel and B. Samet, Coupled fixed point theorems for single-valued operators in b-metric spaces, Fixed Point Theory Appl. (2015) 2015: 231]. Also, we prove that Perov-type fixed point theorem in ordered generalized b-metric spaces is equivalent with Ran-Reurings-type theorem in ordered b-metric spaces.

Dear Editor, A Paper with the title "Compliance of operating room sterilization procedures with valid scientific guidelines" was published by Dr. Batoolsadat Sajadinejad et al (1). in, Vol 9-Issue 4. 2021. This study, which is a descriptive-analytical cross-sectional study, aims to investigate the compatibility of current sterilization procedures of operating room environment and instruments (OR) with valid scientific standards in Vali-Asr Hospital, Birjand. The study results suggest that the quality of infection control and sterilization in the ORs of Vali-Asar Hospital, Birjand is not in accordance with the methods recommended by reasonable scientific standards and guidelines. With thanks and respect to the dear authors, some more points from the statistical point of view should be mentioned: Regarding the sample size, 50 questionnaires are mentioned only in the findings section of the abstract, and it is not clear from the text on which statistical formula and source this figure is based. . .