537 research outputs found
Renal function assessment in adults with recurrent calcium kidney stone disease
The prevalence of nephrolihiasis and chronic kidney disease has risen over the past three decades, we sought to
determine if person with a history of kidney stones have lower renal function relative to non stone formers.
Methods: We conducted a case-control study utilizing 138 recurrent calcium kidney stone formers and 127 age
and gender matched controls with no history of renal disease, all subjects were aged 30-55 years old, with no history
of hypertension, diabetes mellitus, congestive heart failure and liver disease and also no urinary tract obstruction and
medications can affect Glomerular Filtration Rate (GFR).
We estimated GFR by Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology
Collaboration (CKD-EP I) equations and categorized using cut points suggested by Kidney Disease Outcomes Quality
Initiative (K/DOQI) guidelines.
Results: Mean GFR in case group and control group was: 80.17(18.45) ml/min/1.73m2
and 83.80(15.75) ml/
min/1.73m2 respectively (P value: 0.09). Distribution of subjects among stone formers in stage I, II, III was 59(42.8%),
71(51.4%) and 8(5.8%) and in control group was 67(52.8%), 59(46.4%) and 1(0.8%) respectively, (p: 0.03). There was
an inverse correlation between GFR and number of passed stone but there was no significant correlation between
history of extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL) and estimated GFR.
Conclusion: Recurrent calcium stone disease may be associated with nephron damage and an increased risk of
chronic kidney disease
An Optimal Energy Management Strategy for Hybrid Electric Vehicles
Hybrid Electric Vehicles (HEVs) are used to overcome the short-range and long charging time problems of purely electric vehicles. HEVs have at least two power sources. Therefore, the Energy Management (EM) strategy for dividing the driver requested power between the available power sources plays an important role in achieving good HEV performance.
This work, proposes a novel real-time EM strategy for HEVs which is named ECMS-CESO. ECMS-CESO is based on the Equivalent Consumption Minimization Strategy (ECMS) and is designed to Catch Energy Saving Opportunities (CESO) while operating the vehicle. ECMS-CESO is an instantaneous optimal controller, i. e., it does not require prediction of the future demanded power by the driver. Therefore, ECMS-CESO is tractable for real-time operation.
Under certain conditions ECMS achieves the maximum fuel economy. The main challenge in employing ECMS is the estimation of the optimal equivalence factor L*. Unfortunately, L* is drive-cycle dependent, i. e., it changes from driver to driver and/or route to route. The lack of knowledge about L* has been a motivation for studying a new class of EM strategies known as Adaptive ECMS (A-ECMS). A-ECMS yields a causal controller that calculates L(t) at each moment t as an estimate of L*. Existing A-ECMS algorithms estimate L*, by heuristic approaches. Here, instead of direct estimation of L*, analytic bounds on L* are determined which are independent of the drive-cycle. Knowledge about the range of L*, can be used to adaptively set L(t) as performed by the ECMS-CESO algorithm.
ECMS-CESO also defines soft constraints on the battery state of charge (SOC) and a penalty for exceeding the soft constraints. ECMS-CESO is allowed to exceed a SOC soft constraint when an energy saving opportunity is available. ECMS-CESO is efficient since there is no need for prediction and the intensive calculations for finding the optimal control over the predicted horizon are not required. Simulation results for 3 different HEVs are used to confirm the expected performance of ECMS-CESO.
This work also investigates the performance of the model predictive control with respect to the predicated horizon length
Exploring the implementation of FonF tasks from learners’ perspective: a study on young learners
Impact of Awareness Raising about Listening Micro-skills on the Listening Comprehension Enhancement: An Exploration of the Listening Micro-skills in EFL Classes
It is common practice in the classes that teachers focus on the outcome of listening rather than the listening process itself. Based on the interventionist view of language teaching, one of the ways proposed for teaching listening is to break it into smaller micro-skills and give learners awareness about them. But before giving awareness, it is important to identify the micro-skills that learners need mostly in performing listening tasks. This study was aimed at exploring the most frequently used listening micro-skills in EFL classes at lower levels. Also, an attempt was made to investigate the impact of awareness raising about these micro-skills on the EFL learners’ listening comprehension enhancement. For studying the effect of awareness raising, 252 EFL female learners took part in the study and 30 experts and teachers from different universities took part in identifying the most frequently used micro-skills in the EFL context. After gathering data, 10 listening micro-skills were identified as being the most frequently used skills for performing tasks in EFL classes. Also, after awareness raising activities about these micro-skills, a significant difference was found between the learners in the experimental and control groups. The results of the study are discussed in the light of teachers’ language awareness (TLA) and implications for the educators and task designers
The effect of 2 nitroglycerin ointment application on the phlebitis intensity, induced by intravenous catheter
چکیده: زمینه و هدف: شیوع بالای عارضه فلبیت یکی از مسایل مهم در رابطه با تزریقات وریدی می باشد. در بیمارستان هایی که میزان عوارض ناشی از تزریقات وریدی کمتر بوده، مدت اقامت بیماران در بیمارستان و همچنین موارد مرگ و میر کاهش چشمگیری داشته است. این مطالعه با هدف بررسی تاثیر کاربرد پماد نیتروگلیسرین 2 بر شدت فلبیت ناشی از کاتتر وریدی انجام شده است. روش بررسی: در این مطالعه کارآزمایی بالینی یک سو کور 300 نفر از بیماران بستری در بخش قلب و سی سی یو بیمارستان قائم شهر مشهد به روش مبتنی بر هدف انتخاب و به صورت تصادفی در دو گروه شاهد و آزمون قرار گرفتند. در گروه آزمون پس از جایگذاری کاتتر وریدی در قسمت دیستال کاتتر پماد نیتروگلیسرین 2 به میزان 5/0 اینچ گذاشته و پانسمان میشد و در گروه شاهد جایگذاری کاتتر وریدی بدون استفاده از پماد نیتروگلیسرین انجام شد. پس از جایگذاری کاتتر هر 12 ساعت محل کاتتر از نظر وجود علایم فلبیت بررسی و در گروه آزمون پانسمان پماد نیتـــروگلیسرین تعـویض میشد. داده های به دست آمده به کمک آزمون های آماری t مستقل، کای دو و آزمون دقیق فیشر تجزیه و تحلیل شد. یافته ها: شدت فلبیت در گروه آزمون کمتر از گروه شاهد بود (001/0
Resource Management in a Peer to Peer Cloud Network for IoT
Software-Defined Internet of Things (SDIoT) is defined as merging heterogeneous objects in a form of interaction among physical and virtual entities. Large scale of data centers, heterogeneity issues and their interconnections have made the resource management a hard problem specially when there are different actors in cloud system with different needs. Resource management is a vital requirement to achieve robust networks specially with facing continuously increasing amount of heterogeneous resources and devices to the network. The goal of this paper is reviews to address IoT resource management issues in cloud computing services. We discuss the bottlenecks of cloud networks for IoT services such as mobility. We review Fog computing in IoT services to solve some of these issues. It provides a comprehensive literature review of around one hundred studies on resource management in Peer to Peer Cloud Networks and IoT. It is very important to find a robust design to efficiently manage and provision requests and available resources. We also reviewed different search methodologies to help clients find proper resources to answer their needs
Equivalent Consumption Minimization Strategy With Consideration of Battery Aging for Parallel Hybrid Electric Vehicles
The equivalent consumption minimization strategy (ECMS) is a well-known energy management strategy for Hybrid Electric Vehicles (HEV). ECMS is very computationally efficient since it yields an instantaneous optimal control. ECMS has been shown to minimize fuel consumption under certain conditions. But, minimizing the fuel consumption often leads to excessive battery damage. This paper introduces a new optimal control problem where the cost function includes terms for both fuel consumption and battery aging. The Ah-throughput method is used to quantify battery aging. ECMS (with the appropriate equivalence factor) is shown to also minimize the cost function that incorporates battery aging. Simulation results show that the proposed aging ECMS algorithm significantly improves battery aging with little or no fuel economy penalty compared to ordinary ECMS
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