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متن کامل


نویسندگان: 

Shahmoradi Zahra | Mousavi Seyed Hamed

اطلاعات دوره: 
  • سال: 

    2024
  • دوره: 

    43
  • شماره: 

    12
  • صفحات: 

    4524-4547
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    12
  • دانلود: 

    0
چکیده: 

Electro-coalescence has been an environmentally friendly technology for decades. However, Electric Field strength should not exceed a Critical value (Ecrit) to inhibit droplets from disintegrating during coalescence. Response surface methodology (RSM) with a D-optimal design was utilized to develop a model to achieve the maximum Ecrit of a single drop. The p-values showed that all studied variables were statistically significant, including Waveform, frequency, drop diameter, and interfacial tension. The results showed that by increasing the drop diameter,  decreases at all frequencies in the presence and absence of surfactant. Frequency change revealed Ecrit increases with a moderate slope for all waveforms. Because the change in Field periodicity at higher frequencies becomes more frequent, this observation was attributed to a lower degree of drop deformation due to shorter on-time intervals of pulsatile Electric Field and non-compliance of drop vibration with Field frequency. Moreover, the Critical Electric Field declined by decreasing the interfacial tension for all waveforms and the entire frequency range examined. Adding SDS surfactant diminishes the force of surface tension against Electric force and the Critical Field is reduced accordingly. Following  the revelation of the interaction between diameter and frequency, elevated frequencies significantly impact larger droplets, and the sensitivity of Ecrit to the diameter decreases with frequency. This suggests higher frequencies as a valuable and fast controllable variable to compensate for the effect of droplet size distribution. Optimization suggested a minimum drop diameter and a maximum frequency that can be used as two essential limits for the robust electro-coalescer design. The maximum Critical Electric Field was obtained for Pulse 90 at a frequency of 1000 Hz for a drop diameter of 2.12 mm in the absence of the surfactant. These findings can be used to attain the appropriate ranges of variables to design a robust electro-coalescer.

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نویسندگان: 

توحیدی لیلا | پورمیرجعفری فیروزآبادی سیدمحمد | مزدارانی حسین | کوتنیک تادی | پوسیهار گرازد | میکلاوچیچ دامیان

اطلاعات دوره: 
  • سال: 

    1387
  • دوره: 

    5
  • شماره: 

    2 (پیاپی 20-21)
  • صفحات: 

    1-14
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    1855
  • دانلود: 

    218
چکیده: 

مقدمه: الکتروپوریشن یا الکترو تراواسازی یک روش برای افزایش تراوایی غشا سلول توسط میدان الکتریکی خارجی است. این افزایش تراوایی در صورتی آشکار می شود که ولتاژ غشایی القایی با شدت میدان الکتریکی آستانه متناسب است، از یک مقدار بحرانی که بزرگتر شود. در این تحقیق، تغییرات شدت میدان الکتریکی آستانه و نیز ولتاژ غشایی بحرانی منجر به الکتروپوریشن مشاهده پذیر در سلولهای کروی و سلولهای چسبیده با شکل نامنظم، مورد بررسی قرار گرفته است.مواد و روشها: سلولهای کروی با اندازه های مختلف و سلولهای چسبیده با شکلهای متنوع انتخاب شدند. سلولهای انتخاب شده تحت تاثیر چهار پالس الکتریکی با پهنای یکسان 100 میکروثانیه و دامنه افزایشی قرار گرفتند. رخداد الکتروپوریشن با افزایش فلورسانس ناشی از عبور یون کلسیم به داخل سلول، آشکار شده و شدت میدان الکتریکی آستانه برای هر سلول ثبت شد. شکل سه بعدی سلولهای مورد استفاده، از تصاویر سطوح مقطع بدست آمدند. شبیه سازی با روش المان محدود برای بدست آوردن ولتاژ غشایی بحرانی الکتروپوریشن برای سلولهای مختلف انجام شد.نتایج: مقادیر شدت میدان الکتریکی آستانه و نیز ولتاژ غشایی بحرانی برای سلولهای کروی بر حسب شعاع آنها بدست آمد. برای بررسی اثر شکل و جهت گیری سلولها بر شدت آستانه و ولتاژ بحرانی، سلولهای مورد مطالعه بر حسب شکل به سه دسته مجزا تقسیم شدند. مقادیر مورد نظر برای تمام سلولهای هر گروه بدست آمد و نتایج بدست آمده برای هر گروه با یکدیگر مقایسه شدند.بحث و نتیجه گیری: اندازه، شکل و جهت گیری سلولها روی ولتاژ غشایی بحرانی تاثیر می گذارند و تمام این عوامل به نوبه خود شدت میدان الکتریکی آستانه برای ایجاد تراوایی و در نتیجه بازده الکتروپوریشن را تغییر می دهند.

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بازدید 1855

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اطلاعات دوره: 
  • سال: 

    2025
  • دوره: 

    21
  • شماره: 

    2
  • صفحات: 

    3662-3662
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    7
  • دانلود: 

    0
چکیده: 

The study investigates the Electric Field and space charge distributions in propylene carbonate under direct current (DC) applied Fields using Kerr effect. Propylene carbonate is known for its high permittivity and is utilised in many applications, including electrochemical systems and diElectric materials. Understanding the behaviour of Electric Fields and space charge distributions within propylene carbonate is Critical for optimising its performance in these applications. In the study, Kerr effect is employed which by applying the DC Electric Field across the test liquid for measuring the Electric Field and space charge distributions within the propylene carbonate. The experimental setup involved a controlled application of DC Fields, and the Kerr effect measurements were conducted using an optical system. The results show significant understandings into the behaviour of space charges and their influence on the Electric Field distribution in propylene carbonate. Distinct patterns of charge accumulation and Electric Field distortion were observed and analysed in the diElectric liquid properties and charge transport mechanisms. The relationship between Electric Fields and space charges in propylene carbonate under DC conditions has been provided by the findings. The study also shows that the Kerr effect is a useful tool for studying Electric Field distributions in complex materials.

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اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    8
تعامل: 
  • بازدید: 

    192
  • دانلود: 

    0
چکیده: 

IN THE PRESENT STUDY THE EFFECT OF AC ElectricAL Field ON ASPHALTENE PRECIPITATION IS INVESTIGATED. AN ASPHALTENIC CRUDE OIL WITH 11.32WT% ASPHALTENE WAS SELECTED TO CONSIDER THE EFFECT OF AN AC Electric FILED EFFECT ON ASPHALTENE PRECIPITATION. IT WAS SHOWN THAT IN THE PRESENCE OF AN Electric Field, MIXING OF ASPHALTENIC CRUDE OIL WITH HEPTANE LEADS TO ENHANCEMENT OF ASPHALTENE PRECIPITATION. THE PRECIPITATION BEHAVIOR OF ASPHALTENE IN CRUDE OIL-HEPTANE WAS CONSIDERED AT DIFFERENT VALUES OF Electric FieldS AND EXPOSURE TIME OF Field. THE RESULTS SHOWED THAT AN INCREASE IN Electric Field STRENGTH FOR SMALL EXPOSURE TIME UP TO 5 MINUTES A SINUSOIDAL BEHAVIOR IS OBSERVABLE FOR ASPHALTENE PRECIPITATED VALUE WHILE WITH INCREASING THE EXPOSURE TIME OF Field UP TO 30 MINUTES A LOW INCREASING TREND IS OBSERVED FOR ALL THE Electric Field STRENGTH. THIS CAN BE EXPLAINED BY AN INTERACTION BETWEEN THE Electric Field FORCES AND THE CHARGE OF ASPHALTENE PARTICLES. THIS INFORMATION IS USEFUL FOR MANIPULATION OF THE SITUATION WHERE Electric Field IS APPLIED TO ASPHALTENIC CRUDE OILS.

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نویسندگان: 

ZIMMERMANN U. | VICKEN J.

اطلاعات دوره: 
  • سال: 

    1982
  • دوره: 

    65
  • شماره: 

    -
  • صفحات: 

    165-182
تعامل: 
  • استنادات: 

    1
  • بازدید: 

    100
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

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بازدید 100

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اطلاعات دوره: 
  • سال: 

    1393
  • دوره: 

    11
تعامل: 
  • بازدید: 

    293
  • دانلود: 

    108
چکیده: 

لطفا برای مشاهده چکیده به متن کامل (PDF) مراجعه فرمایید.

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اطلاعات دوره: 
  • سال: 

    2016
  • دوره: 

    19
تعامل: 
  • بازدید: 

    161
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

IN THE PRESENT PROJECT WE STUDIED THE INFLUENCE OF AN EXTERNAL Electric Field ON THE STRENGTH AND MECHANISM OF INTERMOLECULAR INTERACTIONS. WE SHOWED THAT AN EXTERNAL Electric Field CAN STRENGTHEN/SOFTEN A CHEMICAL BOND OR CHANGE THE ENERGY BARRIER OF A TRANSITION STATE. THE MAJOR THEME OF OUR RESEARCH IS TO UNDERSTAND THE MECHANISM OF IONRECEPTOR INTERACTIONS IN BATTERIES, SUPERCAPACITORS, ELECTROCHEMICAL ELECTRODES, AND HIGH-Field CONDITIONS LIKE TIP OF SCANNING TUNNELING MICROSCOPE (STM) PROBE. IN THE END, IF TIME PERMITS WE EXPLAIN THE APPLICATION OF AN EXTERNAL Electric Field FOR BUILDING HIGH-DENSITY MEMORIES ON THE BASIS OF ENDOHEDRAL FULLERENES. ...

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بازدید 161

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نویسندگان: 

Gillies Donald

اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    17
  • شماره: 

    42
  • صفحات: 

    80-90
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    136
  • دانلود: 

    25
چکیده: 

The aim of this paper is to consider whether Critical rationalism has any ideas which could usefully be applied to the internet.  Today we tend to take the internet for granted and it is easy to forget that it was only about two decades ago that it began to be used to any significant extent. Accordingly in section 1 of the paper, there is a brief consideration of the history of the internet.  At first sight this makes it looks implausible that any of Popper’s ideas could be applicable to the internet, since Popper died before the internet came into general use.  However, section 2 argues that Popper’s theory of World 3 does apply very well to the internet.  This application is significant because, as shown in section 3, it leads to the problem of misinformation, which is one of the most significant problems generated by the internet.  In section 4 there is an attempt to solve this problem using ideas taken from Popper’s epistemology. It is argued that there should be changes in education designed to prepare students for the internet age. Teaching in the internet age should focus on presenting to the students not just the accepted theories but also the evidence on which they are based. An illustration of how this might be done is given by considering an example from science teaching, namely the teaching of Newtonian mechanics in the last years of school or first years of university.

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نویسندگان: 

Chmielewski Adam

اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    17
  • شماره: 

    42
  • صفحات: 

    205-224
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    114
  • دانلود: 

    12
چکیده: 

In this paper, I address the issue of the possible applicability of the ideas of Karl R. Popper’s social and political philosophy in the contemporary political life of postcolonial countries. Through reference to the reception of Popper’s philosophy in Central and Eastern Europe, I argue that Popper’s writings were effective in catalysing the political wholesale transformation by undermining Marxists’ pretensions to scientific status rather than through his anti-utopian and anti-revolutionary political recommendations. In the context of attempts to apply Popper’s ideas in postcolonial countries, especially Sub-Saharan Africa, I claim that the influence of Popper’s social thought on the politics of those countries may not be as effective as expected or desired.

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نویسندگان: 

Hainscho Thomas

اطلاعات دوره: 
  • سال: 

    1402
  • دوره: 

    17
  • شماره: 

    42
  • صفحات: 

    91-106
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    124
  • دانلود: 

    15
چکیده: 

'Post-truth' has become a buzzword for numerous current crises: the fragmentation of the media landscape, the ongoing debate about 'fake news', the loss of trust in science, etc. Although these crises take place in society, it is claimed that the roots of post-truth can be traced back to the history of philosophy. Occasionally, it is asserted that Karl Popper's Critical rationalism gave rise to post-truth: His rejection of verificationism has limited truth claims in the realm of science. Given the absence of infallible evidence and certainty, Critical rationalism calls for challenging scientific authority. I argue that post-truth is compatible with Critical rationalism from an epistemological point of view, considering that both positions are Critical of certainty. However, in Critical rationalism, fallibilism, responsibility, and the idea of criticism are combined, and in this respect, it offers a possible way to overcome the problems that are associated with post-truth. This treatment of the problems of post-truth results from the recognition of moral responsibility to take action on the basis of a hypothesis that remains open to revision.

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بازدید 124

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