The study of welding and U-press machine maintenance and repairing policies with Markov approach: A case study in APM

This research aimed to clarify maintenance and repairing policies with Markov approach in the case study of Welding and U-press machines in Ahwaz pipe Mills. Documents and the reports of maintenance and accounting unit of the factory are the tools for collecting data. Sampling is the method of data collection in this study prepared by Welding and U-press machines produced in the production line No. 4 of the factory. The data used in this study were related to the year 2010 when the factory was working at full capacity.  The five research questions were used to describe the subject dimensions relating to the replacement policies: Fixed time, fixed course, group replacement, repairing or replacing. The production line No. 4 of Ahwaz pipe Mills factory is the statistical population of the study. Research approach is Markov chain utilized in pipe mills factory according to the description of maintenance and repairing policies. By using probability matrix of previous data, the future behavior was predicted and the production data was used in data mining to investigate further. The results of this study confirmed that choosing correct maintenance and repairing policies according to the study of system behavior and considering the information facilitate the repair costs and indicated a possible solution is not possible for all situations. And proper policy for the U-Press machines is to replace at the fixed time

The study of welding and U-press machine maintenance and repairing policies with Markov approach: A case study in APM

This research aimed to clarify maintenance and repairing policies with Markov approach in the case study of Welding and U-press machines in Ahwaz pipe Mills. Documents and the reports of maintenance and accounting unit of the factory are the tools for collecting data. Sampling is the method of data collection in this study prepared by Welding and U-press machines produced in the production line No. 4 of the factory. The data used in this study were related to the year 2010 when the factory was working at full capacity.  The five research questions were used to describe the subject dimensions relating to the replacement policies: Fixed time, fixed course, group replacement, repairing or replacing. The production line No. 4 of Ahwaz pipe Mills factory is the statistical population of the study. Research approach is Markov chain utilized in pipe mills factory according to the description of maintenance and repairing policies. By using probability matrix of previous data, the future behavior was predicted and the production data was used in data mining to investigate further. The results of this study confirmed that choosing correct maintenance and repairing policies according to the study of system behavior and considering the information facilitate the repair costs and indicated a possible solution is not possible for all situations. And proper policy for the U-Press machines is to replace at the fixed time

The study of welding and U-press machine maintenance and repairing policies with Markov approach: A case study in APM

This research aimed to clarify maintenance and repairing policies with Markov approach in the case study of Welding and U-press machines in Ahwaz pipe Mills. Documents and the reports of maintenance and accounting unit of the factory are the tools for collecting data. Sampling is the method of data collection in this study prepared by Welding and U-press machines produced in the production line No. 4 of the factory. The data used in this study were related to the year 2010 when the factory was working at full capacity.  The five research questions were used to describe the subject dimensions relating to the replacement policies: Fixed time, fixed course, group replacement, repairing or replacing. The production line No. 4 of Ahwaz pipe Mills factory is the statistical population of the study. Research approach is Markov chain utilized in pipe mills factory according to the description of maintenance and repairing policies. By using probability matrix of previous data, the future behavior was predicted and the production data was used in data mining to investigate further. The results of this study confirmed that choosing correct maintenance and repairing policies according to the study of system behavior and considering the information facilitate the repair costs and indicated a possible solution is not possible for all situations. And proper policy for the U-Press machines is to replace at the fixed time

Thoracoscopic Congenital Diaphragmatic Hernia repair in neonate: The First Experience of Iranian Group

Background: Congenital diaphragmatic hernia (CDH) occurs due to a failure in closing pleuroperitoneal membrane thus resulting in an incomplete diaphragm formation1, which allows passage of the abdominal viscera into the thorax.1,3 Until 1995, the standard method for treatment of CDH was performed by open surgery through the abdomen or thoracic cavity. Minimally invasive approach via thoracoscopy or laparoscopy is applicable for treatment of CDH since 1995.4 Now a day’s thoracoscopic repair of CDH (T’Scopy CDH) is performed in many centers. In this paper, we present our experience of T’Scopy CDH repair from Iran.Patients and Methods: From 2011 to 2015, 74 patients with CDH were admitted to Pediatric Surgery Department of Dr. Sheikh (Sarvar) Pediatric Hospital. Twenty one patients (28%) met our inclusion criteria and underwent T’Scopy CDH repair. The median age at the time of repair was 5 days (2-daysold to 4-years-old patients). Inclusion criteria were weight over 2 kg and stable hemodynamics and arterial blood gas. Fourteen cases were intubated before entering the operating room. The defect was in the left side except in two cases. In 8 cases, we used thoracic wall as part of repair. Also, mesh support was utilized in 8 cases even in cases were primary repair of diaphragm was possible in order to reinforcing the repair (5 cases). Of these 8 cases, in 3 patients, whole repair was accomplished by mesh due to presence of a large defect.Results: The mean time of operation was 80 minutes (40-230 minutes). Intraoperative mortality was zero. In hospital, mortality occurred in two cases due to septicemia in one and respiratory and cardiac failure in another. Conversion to open surgery was required in 6 cases. Late recurrence was observed in 2 cases. The mean time of follow up was 14.6 months (3-36 months).Conclusion: It seems that appropriate case selection and liberal use of thoracic wall and mesh as a part of repair may cause better results and decreased chance of early and late recurrence

Magnetic Nanoparticles Linked to Pyridinium Hydrotribromide Groups as Catalysts for Selective Oxidation of Alcohols and Protection of Alcohols

In this research, a novel magnetic nanocatalyst based on iron oxide nanoparticles linked with pyridinium hydrotribromide (Fe3O4@PyHBr3) was synthesized in three steps. In the first step, 3-(aminopropyl)triethoxysilane (APTES) was reacted with 4-(bromomethyl)pyridine hydrobromide. In the second step, the product obtained in the first step was reacted with iron oxide nanoparticles. In the last step, a grinding reaction was carried out with KBr and HIO4 in a mortar. The Fe3O4@PyHBr3 nanocatalyst was characterized by FT-IR, CHN, XRD, SEM, TGA and VSM analysis. The magnetic nanocatalyst was used as a catalyst for the selective oxidation of alcohols to aldehydes and ketones using 30% H2O2 as oxidant in a short time and with high yields. Moreover, no overoxidation of the alcohols was observed. The nanocatalyst was efficiently recycled in five consecutive cycles without significant loss of its catalytic activity. Moreover, trimethylsilylation and tetrahydropyranylation of alcohols were carried out in the presence of this nanocatalyst

Sulfonated Magnetic Nanocomposite Based on Reactive PGMA-MAn Copolymer@Fe 3

Chelating magnetic nanocomposites have been considered as suitable materials for removal of heavy metal ions for water treatment. In this work poly(glycidyl methacrylate-maleic anhydride) copolymer (PGMA-MAn) is modified with 4-aminobenzenesulfonic acid (ABSAc) and subsequently the product reacted with modified Fe3O4 nanoparticles and 1,2-ethanedithiol (EDT) in the presence of ultrasonic irradiation for preparation of tridimensional chelating magnetic nanocomposite. Synthesized magnetic nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), vibrating sample magnetometer (VSM), energy dispersive X-ray analysis (EDX), elemental mapping analysis (EMA), Brunauer-Emmett-Teller (BET), and thermal gravimetric analysis (TGA). The adsorption behavior of Cu(II) ions was investigated by synthesized nanocomposite in various parameters such as pH, contact time, metal ion concentration, and adsorbent dosage. The equilibrium distribution coefficient (kd) was determined and the findings prove that the kd value is approximately high in the case of all selected metal ions. The synthesized nanocomposite exhibited good tendency for removing Cu(II) ions from aqueous solutions even at an acidic pH

Functionalization of polymers and nanomaterials for water treatment, food packaging, textile and biomedical applications: a review

AbstractThe inert nature of most commercial polymers and nanomaterials results in limitations of applications in various industrial fields. This can be solved by surface modifications to improve physicochemical and biological properties, such as adhesion, printability, wetting and biocompatibility. Polymer functionalization allows to graft specific moieties and conjugate molecules that improve material performances. In the last decades, several approaches have been designed in the industry and academia to graft functional groups on surfaces. Here, we review surface decoration of polymers and nanomaterials, with focus on major industrial applications in the medical field, textile industry, water treatment and food packaging. We discuss the advantages and challenges of polymer functionalization. More knowledge is needed on the biology behind cell–polymer interactions, nanosafety and manufacturing at the industrial scale

A Novel Experience in Treatment of Liver Hydatidosis in Pediatrics: A Clinical Trial Study

Background Hydatidosis is a conventional health public problem in most parts of the world. Safe treatment of patients with hydatidosis has been a topic of debate for a long time. Surgical treatment always was associated with high morbidity and mortality. Medical treatment is also controversial. In this study, alternative procedure named Percutaneous, Aspiration and hypertonic Saline Instillation (PAHSI) was applied to treat patients with hydatidosis. Materials and Methods In this single-blind clinical trial, thirty-eight patients, ranging in age between 6 months and 16 years, with 81 hepatic hydatid cysts underwent PAHSI treatment. The consecutive steps including sonographic guidance, aspiration of cyst content and injection of 15% saline hypertonic were carried out in this method. Patients with multiple cysts also were treated by this procedure. Results Participants were 18 boys (47.3%) and 20 girls (52.6%) with mean age of 8.08+ 3.92 years. Almost half of the patients had single cyst (52.63%). During 2- year follow- up, no recurrences were observed; therefore, re-hospitalization and possible complications reduced considerably. Furthermore, this method was applicable to cure multiple cysts. Conclusion In PAHSI strategy, it seems that the complications of surgery (laparotomy and anesthesia) decreased since no complications observed after procedure, and cosmetic results in future are much better due to avoidance of incision

CD133 expression in patients with peripheral neuroblastic tumor: a systematic review

Introduction: Neuroblastoma is known as one of the most common solid tumors in children, which is recently under the investigation for the expression of CD133, a marker of cancer stem cells. Revealing the prognostic value of CD133 marker expression is important in predicting the outcome and survival of neuroblastoma patients. In this systematic review, we aimed to review the studies on association between CD133 expression and other peripheral neuroblastic tumor prognostic factors.Methods: PubMed was searched for the relevant articles. No time and language limitation were included in our search strategy. Data regarding the patients’ number and age, tumor stage, histology and CD133 expression were extracted.Results: Overall, only 4 relevant articles were retrieved. One articles revealed the positive association between CD133 expression in neuroblastoma samples and its resistance to chemotherapy treatment. Three of the included articles showed the positive relation between CD133 expression rate and tumor stage progression. Two of the included studies revealed much worse survival of the neuroblastoma patients with more expression of CD133.Discussion: Based on included studies, CD133 expression is positively related with poor outcome prognosis in patients, more advanced tumor stage, shorter disease-free survival and overall survival. Conclusion: Although the expression of CD133 has shown increasing trend by advancing the neuroblastoma tumor stage, more studies with larger sample size are needed to accurately reveal the relation

Investigating Diagnostic Value of Ultrasonography in Acute Appendicitis

Background: Acute appendicitis is one of the most commonly diagnosed surgical diseases that its accurate diagnosis is still a problem, and there is no certainty. Ultrasound is recommended for diagnosis of appendicitis as an easy and noninvasive method. Therefore, due to the spread of disease and the urgent need to accurately diagnose in all educational centers, we decided to determine the diagnostic value of this inclusive method in identifying acute appendicitis. Materials and Methods: This is a descriptive cross-sectional research that was conducted on 540 patients referring to Educational Center of Ayatollah Kashani Hospital. All individuals suspected to appendicitis, and undergone ultrasound was included in the study, and then the result of ultrasound was compared to the obvious pathological results. Data were entered into statistical software of SPSS 20 and were analyzed. Results: According to the ultrasound findings, appendicitis was diagnosed as negative in 351 ones and positive in 189 ones. Ultrasound sensitivity in the diagnosis of appendicitis was 37.1%, while its specificity was 87.2%. The positive predictive value was 96.8% and the negative predictive value was only 11.7%. Conclusion: Considering very low-negative predictive value in educational centers, it is suggested that ultrasound is done for diagnosis of appendicitis only in complicated cases of appendicitis and differential diagnose (kidney stones, and ovarian cysts). In addition, it is recommended that routine ultrasound be avoided for all patients