An Experimental Investigation on the Effects of MQL Method on Grinding of Nickel Based Superalloy 738 (Inconel 738)

In this research, the usage possibility of minimum quantity lubrication in grinding super alloy Inconel 738 has been studied empirically to reach improved grinding and lubricating conditions. For reaching this purpose, based on Taguchi design of experiment method grinding variables were set in three levels and lubrications were set in six levels in order to compare conventional, dry and MQL methods. Studies have shown that in grinding this material by MQL method we can obtain the results very close to conventional mode in terms of force and surface roughness even having better surface quality. Results in MQL method by considering various oils with different viscosities show that Behzist 6046 and Canola herbal-based oil are the best replacement of conventional method in terms of force reduction and surface roughness. In fact, in the case of using the MQL method together with Behzist 6046 oil, a 50% reduction in the force output is observed and when using Behzist 6043 oil, there is only a 30% difference in the surface roughness obtained with the traditional method, which creates a better surface smoothness is visible. For all the 100 investigated modes, the results show that the optimal levels for the variables of advance speed, stone wheel speed and chipping depth are level 1, 2046 rpm and 5 microns, respectively. The specific vertical force can be predicted in more than 50% of the tests with the least error (about 20%)

Source identification and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments (Case study: Pars special economic energy zone)

Background and purpose: Polycyclic aromatic hydrocarbons (PAH) compounds are amongst the most hazardous environmental pollutants due to some features such as chemical stability, low degradation, bioaccumulation, and high toxicity for living organisms. Their resources are found in Persian Gulf beaches, so, this study aimed at investigating the concentration, source identification, and ecological risk of PAH compounds in coastal sediments in Pars Special Economic Energy Zone (PSEEZ), Iran. Materials and methods: In order to assess the concentration of PAHs, 16 stations along the coast were selected and in each station two samples were collected. After preparation and extraction of samples using Soxhlet, the concentrations of these compounds were determined by HPLC. The toxicity evaluation indicators and diagnostic ratios were used to assess the ecological risk and determining their origin. Results: Mean concentration of PAHs in sediment was 292.72±54.44 ng/g dry weight. The mean effects range-median quotient of the PAHs (M-ERM-Q, M-PEL-Q), toxic equivalence quotient (TEQ), and mutagenic equivalence quotient (MEQ) showed that current values were less than the permissible limit. Comparison of PAHs concentration with sediment quality standards (NOAA, SQGs, and EPA) showed that the values for all compounds were lower than the standard limits (PEC, TEC, PEL, TEL, ERM). However, among these compounds, the average concentration of Acl was higher than the ERL standard and the concentrations of Acl, Ace, and Phe were higher than the EPA toxicity threshold. Conclusion: In this study, moderate PHAs pollution was seen in the region. Both petrogenic and fuel sources were found to be involved in introduction of these compounds into coastal sediments depending on the location of the station and its sources of contamination. Also, in terms of ecological risk, these compounds have low risks for living organisms. © 2018, Mazandaran University of Medical Sciences. All rights reserved

Determination of mercury, lead, arsenic, cadmium and chromium in salt and water of Maharloo Lake, Iran, in different seasons

Background and purpose: Today, environmental pollutions are of the most important issues and hazardous in food safety around the world. Given the importance of salt and water in dietary, and extracting them from Maharloo Lake, Iran, this study aimed to investigate the concentrations of heavy metals, as environmental pollutions, in salt and water of this lake at different seasons. Materials and methods: In order to monitor heavy metals, including chromium (Cr), mercury (Hg), arsenic (As), cadmium (Cd) and lead (Pb), water and salt samplings were done in each season from August 2009 to May 2010. Using atomic absorption, the concentration of the mentioned metals was determined after digesting the samples. Results: The order of concentration of detected metals in different seasons in salt was Cr > As > Cd > Pb > Hg, and in water was Cr > As > Hg > Cd > Pb. In salt, the highest concentrations of Cr, Cd, Pb, and As were detected in spring and of Hg was seen in summer. Also in water, the highest concentrations of As and Cd were detected in spring, of Cr and Hg in summer, and of Pb in autumn. Conclusion: In summary, it could be concluded that the changes in the concentration of metals during different seasons was caused by the changes in the inlet water and human activities, especially agricultures. In addition, compared to Iranian standard, determined concentrations of Pb and Hg in salt samples were lower

Persian Identity Aspects in Delgosha's System of Poems based on Shahnameh's Ferdowsi Re-creations

Poetic historiography has been formed as one of the historiographical forms of the Mongolian period, following the advent of historiography. In this historiography, as its name implies, history is written in order. The poetic historiography provides a lot of information about the reconstruction of some of the historical events of this time and in terms of showing evidence of the revival of the Iranian and the Persian language. Although the Ilkhani and Timurid periods are the most important periods in Iran's poetic historiography, and many epopees have been created in this age, this kind of historiography has been less studied by researchers. The present research seeks to study the ideas of Iranian identity by a descriptive-analytical method in the poem called Daftar Delgosha by Saheb Shabankareh. The results of the research show that, in Saheb Shabankareh's opinion, the history and historical past have played the most important role in the restoration and reconstruction of the Iranian identity in Islamic times. The deep view of the poet towards Ferdowsi and the influence of Shahnameh have led him to repeatedly refer to the characters and heroes of Shahnameh in his poem. Sometimes even his heroes consider themselves superior to the champions of Shahnameh

A Randomized Triple-Blind Clinical Trial of the Effect of Low-Level Laser Therapy on Infiltration Injection Pain in the Anterior Maxilla

Objective: To evaluate the level of pain experienced during infiltration anesthesia of the anterior maxilla following low-level laser therapy (LLLT) with 810-980 nm wavelengths. Material and Methods: In the current triple-blind clinical trial, 84 patients received a total of 168 infiltration anesthesia injections (1.8 mL of 2% lidocaine plus 1:100,000 epinephrine) in the anterior maxilla. Each patient received two injections into the buccal mucosa of the right and left central incisors with a two-week interval. One injection was performed after LLLT, while the other injection was administered conventionally without laser. The pain level was measured immediately after injection using a visual analog scale (VAS). Results: There was a significant difference in the pain level experienced with and without LLLT, such that the mean pain score following LLLT was significantly lower than that without LLLT (p<0.05). No significant difference was found in the pain level between laser and no laser groups in males, but the difference in this regard was significant in females (p<0.05) and female patients experienced a significantly lower level of pain following LLLT. Conclusion: The low-level laser therapy can be successfully used to decrease the level of pain experienced during infiltration anesthesia of the anterior maxilla

Determination and Ecological Risk Assessment of Heavy Metals (Cd, Pb, Cu, Zn) in Surface Sediments of Coastal Regions of Bushehr Province

Background: Persian Gulf is one of the most important ecosystems in the world that in recent decades has been exposed to various environmental pollutants such as heavy metals from human and natural activities. Therefore, the aim of this study investigates the concentration of heavy metals (cadmium, lead, copper and zinc) and ecological risk assessment of them in coastal sediments in of Bushehr province in Persian Gulf. Methods: In order to assess the concentration of metals, 54 stations along the coastal zones were selected and in each station three samples of sediment and plant were taken. After preparation and digestion of the samples, the concentrations of these metals were determined by using polarography. Results: The average of total concentration of detected metals Zn, Cu, Pb and Cd in sediment 52.40 ± 2. 62, 34.99±2.76, 11.53 ±2.01 and 2.41± 0.89 μg/g, respectively. Also, the results of comparison of heavy metals concentration in coastal areas in Bushehr Province (Jam, Deir, Bushehr, Dashti, Genaveh and Deilam) with ANOVA test showed there was a significant difference between the concentrations of sediments in different coastal areas. The results showed that the Pollution Load Index (PLI) and ecological risk represents less to moderately pollution in the region. Also, the environmental risk of metals in the region was evaluated as (Cd>Cu> Pb> Zn). Conclusion: According to the results, the pollution and ecological risk of metals in the region for Zn, Cu and Pb is low but for Cd is moderateevaluated

The Relationship between the Results of Coagulation Profile and Severity of Pulmonary Involvement in COVID-19 Patients

Introduction: COVID-19 is currently a global pandemic, and coagulation-related mortality has been widely reported in patients suffering from it. Objective: this article aimed to investigate the coagulation profile of COVID-19 patients. Methods: This was a cross-sectional study conducted using a retrospective research design. We recruited patients with COVID-19 admitted to a hospital from June 15th to July 7th, 2020. Upon patients' entering a blood sample was drawn from each patient for assessing patient’s coagulation profile (PT, PTT, INR, Platelet count); and a chest high-resolution computed tomography (HRCT) scan was performed for each patient. The study patients were divided in to sever group (CO-RADS score 5) and non-sever group (CO-RADS score <5). Results: Thirty-six patients (20 males and 16 females) with a mean age of 54.7±17.5 years were studied. Of them, 11 cases (30.56%) had severe pulmonary involvement. Also, the coagulation profiles were longer in the severe group than non-sever group. As well, the means of platelet count that were 232.440 per microliter in the non-severe group and 289.180 per microliter in the severe and non-sever groups, respectively; but still not statistically significant (p>0.05). The Area under the ROC Curve (AUC) for PT and INR was 0.615 and 0.611, respectively. The AUC for platelet count was 0.680 (95% CI: 0.501 to 0.859) and had an acceptable discriminating power. Conclusions: In this study, we did not find any statistically significant relationship between the results of coagulation tests and the severity of pulmonary involvement according to HRCT scan findings in COVID-19 patients. But further analyses suggest that, except PTT, the other coagulation tests (PT, INR, and platelet count) may discriminate severe COVID-19 patients

The Employment of Learning Orientation in Promoting the Innovative Behavior for the Employees of the Directorate of Education in Najaf: A Survey

الغرض: يسعى البحث الحالي الى معرفة طبيعة العلاقة بين اتجاه التعلم (Learning orientation) وسلوك الابتكار(Innovative Behavior), وكذلك معرفة تأثير المتغير المستقل(اتجاه التعلم)  بأبعاده الاربعة (الالتزام بالتعلم, مشاركة الرؤية, انفتاح الذهني, تبادل المعرفة) والذي تم قياسه باستخدام مقياس(Calantone, Cavusgil & Zhao, 2002) على المتغير التابع(سلوك الابتكار) بأبعاده الستة (توليد الفكرة, البحث عن فكرة, اتصالات الفكرة, انشطة بدء التنفيذ, اشراك الاخرين, التغلب على العقبات) والذي تم قياسه باستخدام مقياس(Lukeš, & Stephan, 2017). التصميم/المنهجية: تم تطبيق البحث على عينة من الموظفين العاملين في مديرية تربية النجف الاشرف وتم اختيار عينة عشوائية بسيطة مكونة من (93) موظفا, واعتمد البحث الحالي الاستبانة اداة رئيسة لجمع البيانات, وسعى البحث لاختبار علاقة الارتباط والتأثير لبيان العلاقة بين متغيرات البحث, وتم اعتماد عدة تحليلات احصائية  لمعالجة البيانات منها الفا كور نباخ  والمتوسط الحسابي  الموزون والانحراف المعياري  ومعامل الارتباط البسيط وتحليل الانحدار باستخدام البرنامج الاحصائي (SPSS  VR.23). اهمية البحث: تبرز اهمية البحث الحالي من ندرة الدراسات التي تناولت العلاقة بين متغيرات اتجاه التعلم واسلوك الابتكار) وكذلك محاولة البحث الحالي دراسة ومعالجة مشكلة واقعية تؤثر بشكل مباشر على الافراد العاملين والمجتمع في مديرية تربية النجف الاشرف. النتائج: توصل البحث الى استنتاجات معرفية وتطبيقية  منها وجود علاقة ارتباط ذات دلالة احصائية  بين المتغير المستقل والمتغير التابع  ووجود تأثير ذو دلالة احصائية بين  اتجاه التعلم وسلوك الابتكار. التوصيات: -1على المنظمة قيد الدراسة الاهتمام باتجاه التعلم  لدى العاملين وترسيخ هذا السلوك في ممارسات عملهم اليومي. -2على المنظمة قيد الدراسة تشجيع سلوك الابتكار بين العاملين بالشكل الذي يؤدي الى تحقيق التميز والنجاح التنظيمي.Purpose: The current research seeks to know the nature of the relationship between learning orientation and innovation behavior, as well as to know the effect of the independent variable (learning orientation) in its four dimensions (commitment to learning, sharing of visionOpen-mindedness, Intraorganizational knowledge sharing), which was measured using a scale (Calantone, Cavusgil & Zhao, 2002)The dependent variable (innovation behavior) with its six dimensions (idea generation, idea search, idea communication, Implementation starting activities, engaging others, overcoming obstacles), which was measured using the scale (Lukeš, & Stephan, 2017). Design /methodology: The research was applied to a sample of employees working in the in  Education Directorate Najaf, and a simple random sample consisting of (93) employees was chosen. The current research adopted the questionnaire as a main tool for data collection, and the research aims to test the relationship and influence to find out the relationship between the research variables. Several statistical analyzes were adopted to process the data, including Cronbach's Alpha the weighted mean, standard deviation, simple correlation coefficient and regression analysis using the statistical program (SPSS VR.23). The importance of the research: The importance of the current research emerges from the lack of studies that dealt with the relationship between the variables of the learning orientation and innovation behavior) as well as the current research attempt to study and address a realistic problem that directly affects the working individuals and society in the in  Education Directorate Najaf. Results: The research reached cognitive and applied conclusions, including the existence of a statistically significant correlation between the independent variable and the dependent variable and the presence of a statistically significant effect between the direction of learning and the behavior of innovation. Recommendations: 1-The organization under study should pay attention to the direction of learning among workers and instill this behavior in their daily work practices. 2-The organization under study is required to encourage innovation behavior among employees in a manner that leads to achieving organizational excellence and success

A Randomized Triple-Blind Clinical Trial of the Effect of Low-Level Laser Therapy on Infiltration Injection Pain in the Anterior Maxilla

Objective: To evaluate the level of pain experienced during infiltration anesthesia of the anterior maxilla following low-level laser therapy (LLLT) with 810-980 nm wavelengths. Material and Methods: In the current triple-blind clinical trial, 84 patients received a total of 168 infiltration anesthesia injections (1.8 mL of 2% lidocaine plus 1:100,000 epinephrine) in the anterior maxilla. Each patient received two injections into the buccal mucosa of the right and left central incisors with a two-week interval. One injection was performed after LLLT, while the other injection was administered conventionally without laser. The pain level was measured immediately after injection using a visual analog scale (VAS). Results: There was a significant difference in the pain level experienced with and without LLLT, such that the mean pain score following LLLT was significantly lower than that without LLLT (p<0.05). No significant difference was found in the pain level between laser and no laser groups in males, but the difference in this regard was significant in females (p<0.05) and female patients experienced a significantly lower level of pain following LLLT. Conclusion: The low-level laser therapy can be successfully used to decrease the level of pain experienced during infiltration anesthesia of the anterior maxilla