Classification system of the physical streambed habitat.

A streambed is the channel bottom of a stream, river, or creek; the physical confine of the normal water flow. It provides necessities for fish and microinvertebrate including shelter, food, and breeding spots. Therefore, it is an essential part of aquatic animal habitats and often seen as an index of stream health. There is no generally accepted method to quantify streambed physical components and depending upon state and organization a variety of methods are used. The procedure provided in the rapid bioassessment protocol (RBP) (Kaufmann et al., 1999; Sylte and Fischenich, 2002) is probably the most widely used method to assess the effect of various land use activates on stream habitat for management purposes in the United States. The RBP method was not intended as a procedure to assess streambed habitat; although it is often used for this purpose. This approach reduces the streambed physical components into the two variables: embeddedness and epifaunal substrate. Definitions and sampling procedure of these variables are vague and subjective. Streambed components with varying characteristics are grouped under the same category and some streambed components as important as gravel are not included in the categorizing of the streambed habitat. A measurement method that combines a photographic technique and grid sampling was developed to assess streambed components in a direct and simple way at the required level of accuracy. The portable photographic box (PPB) device utilizes a photographic technique to record images of physical streambed components under typical base flow of wadeable gravel-bed streams. Recorded images were digitized manually and the area of each streambed component in each grid cell was estimated to evaluate projected area of streambed component. The PPB facilitates sampling of streambed components of unit population with adequate picture quality rapidly. Five scenarios for sampling methods with varying accuracy and field and laboratory time requirements for quick and simple inventory of impaired stream habitat were recommended. Based on statistical analysis, residual was reduced from 33% in the rapid bioassessment to 28%, 14%, 7%, 5% and 0% in the first, second, third, fourth, and fifth scenario, respectively. In addition, measurement of the dissolved oxygen and temperature in ten riffles indicated that temperature in the first layer of subsurface was similar to those measured in the water column. No evidence was found to support substrate measurement of temperature. However, the dissolved oxygen concentration varied significantly for embedded and free patches. In contrast to the free gravel and epifaunal substrate, the DO content in fine material, embedded gravel, and embedded epifaunal substrate components was in anoxia and hypoxia. Hypoxia and anoxia lasted for several days after flood events

Diffusion through the ex vivo vitreal body - bovine, porcine, and ovine models are poor surrogates for the human vitreous

© 2018 The Authors. Published by Elsevier B.V.The human vitreous humour is a complex gel structure whose composition and physical properties can vary considerably from person to person and also change with age. To date, the viscoelastic properties of the human vitreous gel has not been thoroughly investigated and despite many years of intensive research, an ideal vitreous substitute remains a challenge. Understanding the physical structure and properties of the vitreous is of fundamental and therapeutic interest, providing a clear insight into diffusion and transport of administered ophthalmic drug molecules into the vitreous. A number of mammalian surrogates, mainly bovine, porcine and ovine vitreous humours have been greatly used in the literature as a means of studying ophthalmic drug transport and diffusion. In this study, the mechanical, physical and rheological properties of ovine, porcine, and bovine surrogates were investigated and compared to human vitreous. In addition, a bespoke Franz cell construct was used to compare the diffusion of a model drug (i.e. fluorescein) through vitreous samples. Despite the similarity in rheological properties between bovine, porcine and human vitreous samples (p > 0.05), diffusion of fluorescein through the different vitreous samples revealed great differences in values of steady-state flux and diffusion coefficient. In addition, a first-generation vitreous mimic, composed of 4.5 mg/mL hyaluronic acid with complex viscosity of 0.3 ± 0.01 Pa has been evaluated and was demonstrated to be a better mimic of the human vitreous than the mammalian samples investigated.Peer reviewedFinal Published versio

Mathematical Modelling of Magnetic Abrasive Machining Hybrid Operation: A Review

الانهاء بالحث الممغنط هو طريقة انهاء سطحي غير تقليدي لإنتاج اجزاء ذات نوعية عالية والتي يسيطر عليها بالطاقة المغناطيسية. طورت عملية الحك الممغنط بعض الخواص الميكانيكية للسطح. بعض طرق الانهاء السطحي التقليدية مثل تنعيم السطح الداخلي، التجليخ والتنعيم الخارجي بدلت الان بهذه الطريقة. في هذا البحث (مراجعة) سنتناول بالتفصيل اساس عملية الانهاء بالحث الممغنط، متغيرات العملية وتأثيرها على المخرجات (الاستجابة)، نمذجة العملية وتطورها للسطوح المستقيمة. اضافة الى ذلك هناك نوع جديد من الانهاء بالحث الممغنط المندمج مع التشغيل الكهروكيمياوي لإنتاج التشغيل بالحك الممغنط الكهروكيمياوي. اداء النموذج الرياضي والامثلية المتعددة لتنبأ المخرجات مثل معدل الازالة المعدنية، الانهاء السطحي والمنطقة المتأثرة بالحرارة.... الخ وجدت للمقارنة بدلالة دقة وسرع التنبؤ.   Magnetic Abrasive Finishing (MAF) or super finishing is a modern unconventional finishing technique to produce high quality of parts, which is controlled by a magnetic energy. Magnetic abrasive operation develops some of the mechanical properties such as the surface quality. Nowadays, many of the traditional finishing technique such as honing, polishing and grinding are now being replaced by this process. In this review, principles of the MAF process, processing factors and their influence on the responses, the process modeling and development of the MAF method for flat surfaces will be examined in details research work in the literature. Additionally, there is a new type of MAF connected with Electrochemical Machining (ECM) to produce Electrochemical Magnetic Abrasive Machining (EMAM). The performance of models and multi-optimizing for predicting the responses such as metal removal rate (MRR), surface finish (SF), heat affected zone (HAZ) etc. are found to comparable in terms of the prediction accuracy and speed. &nbsp

Is adiponectin associated with acute myocardial infarction in Iranian non obese patients?

<p>Abstract</p> <p>Backgrounds</p> <p>Adiponectin is an adipose tissue-derived mediator with significant anti-atherogenic properties. A few studies were done in acute phase of myocardial infarction especially in non obese patients. We design a study to investigate the association between adiponectin concentration and acute phase of myocardial infarction in non obese patients.</p> <p>Methods</p> <p>This case-control study was done in Paymaneah Hospital (Jahrom, Iran) from Feb 2007 to May 2008. Plasma adiponectin levels were measured in 43 patients with AMI (mean age: 62.7 ± 13.3 years, male: 67.4%) at the first 24 hours of admission and 43 normal controls (mean age: 62.1 ± 12.3 years, male: 55.8%) matched for age, sex and other CAD risk factors.</p> <p>Results</p> <p>Adiponectin levels in patients with AMI (3.36 μg/mL) were significantly lower than that of the control group (5.03 μg/mL) (p < 0.0001). Lower adiponectin were independently associated with higher risk of AMI (odds ratio = 8.97; 95% CIs: 2.3–34.5; p = 0.001). Adiponectin levels negatively correlated with triglyceride (r = -0.46, p = 0.002) and total cholesterol (r = -0.32, p = 0.03) in the case group and with body mass index (BMI) in control subjects.</p> <p>Conclusion</p> <p>The present study showed that adiponectin was associated with AMI in non obese patients but it is not related to sex, age and other CAD risk factors.</p

Optimization of EDM Process Factors for Machining Al-Si Alloy Using Response Surface Methodology

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; يقدم هذا البحث نهجا متكاملا لنمذجة العملية والأمثلية متعددة الاهداف لمتغيرات التشغيل بالشرارة الكهربائية لسبيكة الالمنيوم سيليكون (Al-Si) اعتمادا على نمط استجابة السطح (RSM) إلى جانب تكنيك دالة الرغبة (DF). أختيرت ثلاث متغيرات منفصلة كمدخلات وهي تيار النبضة (Ip)، فترة إفراغ النبضة (Ton) وفترة توقف النبضة (Toff) للتأكد من تأثير المتغيرات الثلاث سابقة الذكر على المخرجات المتمثلة بمعدل إزالة المادة (MRR)، معدل بلى القطب (EWR) وخشونة السطح (Ra). تحليل عام للتفاوت (ANOVA) عند درجة من الأهمية مقدارها 5% لتعيين المعاملات الأكثر تأثيرا، وأنجز اختبار مدى كفاءة كافة النماذج. ولفهم السلوك الشامل لقابلية تشغيل لسبيكة الالمنيوم سيليكون (Al-Si) تحت أوضاع التشغيل المتفاوتة، تم إجراء تحليل التأثير الأساسي. بينت النتائج ان معدل الازالة المعدنية يزداد مع رفع تيار النبضة وفترة إفراغ النبضة. يمكن الاستحصال ايضا على نقصان في كل من معدل بلى القطب وخشونة السطح عن طريق خفض تيار النبضة ووقت إفراغ النبضة. ومع ذلك، فإن تيار النبضة هو العامل المتحكم (الاكثر تأثيرا) على معدل الازالة المعدنية وخشونة السطح متبوعا زمن تفريغ النبضة وزمن توقف النبضة، في حين أن في معدل بلى القطب فان تيار النبضة هو العامل الاكثر تأثيرا يليه زمن توقف النبضة وزمن إفراغ النبضة. أخيرا استعملت أسلوب الامثلية متعددة الاهداف بالاعتماد على نظرية دالة الرغبة للاستحصال على المقدار الامثل لمتغيرات التشغيل بحيث يمكن الاستحصال من خلالها على اعلى مقدار لمعدل الازالة المعدنية وأدنى مقدار لكل من متوسط بلى القطب وخشونة السطح مع المتغيرات المؤثرة.This work exhibits an incorporated way to deal with the procedure demonstrating and multi-target improvement of EDM parameters of Al-Si based on response surface methodology (RSM) combined with desirability function (DF) method. The’ effect’ of’ process’ parameters&nbsp; &nbsp;for’ example, pulse current (Ip), pulse’ on’ time’ (Ton) as well as pulse’ off’ time’ (Toff) on’ metal removal’ rate’ (MRR), electrode’ wear’ rate’ (EWR) and’ surface’ roughness’ (Ra), were analyzed. An extensive investigation of difference (ANOVA) at fixed indicative level of 5%, was done to completely distinguish the most persuasive parameters, and the sufficiency of all fitted relapse models were checked. To completely comprehend the trademark machinability conduct under various EDM conditions, fundamental effect investigation. The results indicate that MRR increases with the rising Ip and Ton. Low EWR and Ra can be acquired by diminishing Ip and Ton. Be that as it may, the Ip is the most commanding parameter pursued by Ton and Toff for MRR and Ra whereas in the EWR, the Ip is the foremost factor, followed by the Toff and Ton. Lastly, a multi-optimization way dependent upon the desirability function (DF) idea was used to discover ideal blends of machining parameters so that it was capable to produce the the most extreme estimation of MRR and least estimations of EWR and Ra, inside the noteworthy information parameters

Optimization of Friction Stir Welding Parameters of Al 6061 and Al 7075 Using GRA

لحام الخلط الاحتكاكي هو تكنولوجيا واعدة لربط سبائك الألومنيوم غير المتشابهة. سبائك الالمنيوم تستخدم بصورة شائعة في صناعات الفضاء مثل ابدان الطائرات والالواح والأجنحة نظرا لمتانته العالية نسبه الى وزنه. لذلك هنالك محاوله للوصول الى أمثليه متغيرات عمليه اللحام الاحتكاكي عند لحام سبيكتين من الالمنيوم هما6061 و7075 باستخدام برنامجMinitab 16 &nbsp;من اجل تحسين خصائص الشد مثل اجهاد الخضوع (YS) ومتانة الشد القصوى(UTS) ونسبة الاستطالة(E) . طريقه Taguchi استخدمت كأساس لتحليل العلاقة الرمادية (GRA) باستخدام عاملين هما سرعه دوران الاداة (TRS) وسرعه اللحام (WS بأربع مستويات. النتائج اظهرت ان المتغيرات التي هي سرعه دوران الاداة وسرعه اللحام لها تأثير كبير على اجهاد الخضوع ومتانة الشد القصوى ونسبة الاستطالة. كما اظهرت النتائج ان طريقه Taguchi المستخدمة كأساس لتحليل العلاقة الرمادية تحسن المخرجات لسبيكتي الالمنيوم 6061 7075 الملحومتان.Friction stir welding (FSW) is proved as a promising welding technology for joining dissimilar aluminium alloys. Aluminium alloys are used extensively within the aerospace industry for applications such as fuselage and wing skin panels due to their high strength to weight ratio. Therefore, an effort is made to optimize the process parameters of FSW using Al 6061 and Al 7075 alloys by the Minitab 16 program in order to enhance &nbsp;tensile properties such as elongation (E), yield stress (YS), and ultimate tensile strength (UTS). Grey relational analysis (GRA) based on the Taguchi method is applied using two factors tool rotational speeds (TRS) and welding speed (WS) with four levels. Results show that the variables, namely the tool rotation speed and welding speed have a significant effect on yield stress, ultimate tensile strength and elongation. Results also show that the Taguchi based grey relational approach improved properties of output response of welded Al 6061 and Al 7075 aluminum alloys

Probabilistic Seismic Performance Assessment of Tall RC Special Moment-resisting Frame Buildings Equipped with Buckling-restrained Braces under Near-field Excitations

Many tall buildings have already been constructed near faults throughout the world, several of which have sustained casualties and economic losses during strong ground motions. This study investigates the effect of near-fault excitations on the vulnerability of tall, reinforced concrete (RC) special moment-resisting frame (SMRF) buildings equipped with buckling-restrained braces (BRBs) using seismic fragility curves. After attaining the structure’s response modification factor (R), three-dimensional (3D) models of 15-, 25- and 35-story frames were developed by the OpenSees software according to the Iranian code provisions. Thus, the seismic response of the elements was obtained. Subsequently, incremental dynamic analysis (IDA) was conducted by selecting a suitable number of compatible accelerograms in two near-field and far-field groups. Considering the maximum story drift as the demand parameter and selecting the interstory drift ratios (IDR) for the slight, moderate, extensive, and complete collapse seismic performance levels proposed by Hazus, IDA curves were plotted. Then, the seismic fragility curves were produced using the structural reliability relations. The median fragility at complete collapse damage level reduced from 0.73g, 0.62g, and 0.61g to 0.68g, 0.59, and 0.57g for the 15-, 25, and 35-story near-field and far-field earthquake models, respectively. This was attributed to increasing vulnerability and seismic fragility of the structures as a result of both height increase and distance reduction from fault. Based on the results, the most vulnerable structure, i.e., the 35-story near-fault model, experienced a 40, 17, 18, and 6% increase in median fragility at slight, moderate, extensive, and complete collapse damage levels, respectively

Effects of acupressure at the hugo point (LI4) on labor pain and duration of delivery in nulliparous women

Introduction: Most women have experienced child birth and its pain, which is inevitable. If this pain is not controlled it leads to prolonged labor and injury to the mother and fetus. This study was conducted to identify the effect of acupressure on sanyinjiao and hugo points on delivery pain in nulliparous women. Methods:This was a randomized controlled clinical trial on 84 nulliparous women in hospitals of Ardebil, Iran. The participants were divided by randomized blocks of 4 and 6 into two groups. The intervention was in the form of applying pressure at sanyinjiao and hugo points based on different dilatations. The intensity of the pain before and after the intervention was recorded by visual scale of pain assessment. To determine the effect of pressure on the intensity of labor pain, analytical descriptive test was conducted in SPSS (version 13). Results:There was a significant decrease in mean intensity of pain after each intervention in the experimental group with different dilatations (4, 6, 8, and 10 cm). Moreover, the Student’s independent t-test results indicated that the mean intensity of pain in the experimental group after the intervention in all four dilatations was significantly lower than the control group. Repeated measures ANOVA test indicated that in both experimental and control groups in four time periods, there was a statistically significant difference. Conclusion:Acupressure on sanyinjiao and hugo points decreases the labor pain. Therefore, this method can be used effectively in the labor process

Protecting River Environment through Proper Management of Material Mining by Matrix Method (Case Study of A'la River in Iran)

Regarding the importance of rivers, appropriate management of aggregate mining is of great significance. Mining of river materials has a direct impact on environmental conditions of the river. Today, aggregate mining management represents a crucial topic in river engineering. Often selected based on the pattern of the considered river, matrix method provides a suitable approach to improve the river aggregate mining management. The present research aims at presenting the application of the matrix method in river material mining location evaluation. Given the capabilities of the matrix method for determining potential of mine area and aggregate mining method, this method can be seen as a suitable solution for reducing negative environmental impacts of river material mining. A'la River is one of the most important rivers streaming in Khouzestan Province (Iran), with its sediment load and mining potential being of critical importance. In this research, the reach of A'la River at the intersection of Rood-Zard River and Rahmhormoz diversion dam was studied for aggregate mining and application of matrix method. The main purpose of this work is to study the application of matrix method to A'la River. The results indicate braided pattern of the river and appropriateness of the matrix method. Available volume of aggregate for mining within the mentioned reach of A'la River was estimated as 50,000 m3, and scraping method at a maximum depth of 1 m was proposed for mining of the aggregates