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Deborah Number
The Deborah number (De) is a dimensionless number, often used in rheology to characterize the fluidity of materials under specific flow conditions. It quantifies the observation that given enough time even a solid-like material might flow, or a fluid-like material can act solid when it is deformed rapidly enough. Materials that have low relaxation times flow easily and as such show relatively rapid stress decay. Definition The Deborah number is the ratio of fundamentally different characteristic times. The Deborah number is defined as the ratio of the time it takes for a material to adjust to applied stresses or deformations, and the characteristic time scale of an experiment (or a computer simulation) probing the response of the material: : \mathrm = \frac, where stands for the relaxation time and for the "time of observation", typically taken to be the time scale of the process. The numerator, relaxation time, is the time needed for a reference amount of deformation to occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimensionless Number
A dimensionless quantity (also known as a bare quantity, pure quantity, or scalar quantity as well as quantity of dimension one) is a quantity to which no physical dimension is assigned, with a corresponding SI unit of measurement of one (or 1), ISBN 978-92-822-2272-0. which is not explicitly shown. Dimensionless quantities are widely used in many fields, such as mathematics, physics, chemistry, engineering, and economics. Dimensionless quantities are distinct from quantities that have associated dimensions, such as time (measured in seconds). Dimensionless units are dimensionless values that serve as units of measurement for expressing other quantities, such as radians (rad) or steradians (sr) for plane angles and solid angles, respectively. For example, optical extent is defined as having units of metres multiplied by steradians. History Quantities having dimension one, ''dimensionless quantities'', regularly occur in sciences, and are formally treated within the field of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Book Of Judges
The Book of Judges (, ') is the seventh book of the Hebrew Bible and the Christian Old Testament. In the narrative of the Hebrew Bible, it covers the time between the conquest described in the Book of Joshua and the establishment of a kingdom in the Books of Samuel, during which biblical judges served as temporary leaders. The stories follow a consistent pattern: the people are unfaithful to Yahweh; he therefore delivers them into the hands of their enemies; the people repent and entreat Yahweh for mercy, which he sends in the form of a leader or champion (a "judge"; see ''shophet''); the judge delivers the Israelites from oppression and they prosper, but soon they fall again into unfaithfulness and the cycle is repeated. Scholars consider many of the stories in Judges to be the oldest in the Deuteronomistic history, with their major redaction dated to the 8th century BCE and with materials such as the Deborah#The Song of Deborah, Song of Deborah dating from much earlier. Conte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimensionless Numbers Of Fluid Mechanics
A dimensionless quantity (also known as a bare quantity, pure quantity, or scalar quantity as well as quantity of dimension one) is a quantity to which no physical dimension is assigned, with a corresponding SI unit of measurement of one (or 1), ISBN 978-92-822-2272-0. which is not explicitly shown. Dimensionless quantities are widely used in many fields, such as mathematics, physics, chemistry, engineering, and economics. Dimensionless quantities are distinct from quantities that have associated dimensions, such as time (measured in seconds). Dimensionless units are dimensionless values that serve as units of measurement for expressing other quantities, such as radians (rad) or steradians (sr) for plane angles and solid angles, respectively. For example, optical extent is defined as having units of metres multiplied by steradians. History Quantities having dimension one, ''dimensionless quantities'', regularly occur in sciences, and are formally treated within the field of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AIChE
The American Institute of Chemical Engineers (AIChE) is a professional organization for chemical engineers. AIChE was actually established in 1908 to distinguish chemical engineers as a profession independent of chemists and mechanical engineers. As of 2018, AIChE had over 60,000 members, including members from over 110 countries worldwide.About the AIChE, Overview (from the AIChE website) Student chapters at various universities around the world have also been established throughout its history. The student chapters tend to focus on providing networking opportunities in both academia and in industry as well as increasing student involvement locally and nationally. History of formation :''This section consists of excerpts from a historical pamphlet written for the Silver Anniversary of the AICHE in 1932.'' In 1905, ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Williams–Landel–Ferry Equation
The Williams– Landel– Ferry Equation (or WLF Equation) is an empirical equation associated with time–temperature superposition. The WLF equation has the form : \log(a_T) = \frac where ''\log(a_T)'' is the decadic logarithm of the WLF shift factor, ''T'' is the temperature, ''T''r is a reference temperature chosen to construct the compliance master curve and ''C''1, ''C''2 are empirical constants adjusted to fit the values of the superposition parameter ''a''T. The equation can be used to fit (regress) discrete values of the shift factor aT vs. temperature. Here, values of shift factor aT are obtained by horizontal shift log(aT) of creep compliance data plotted vs. time or frequency in double logarithmic scale so that a data set obtained experimentally at temperature T superposes with the data set at temperature Tr. A minimum of three values of aT are needed to obtain C1, C2, and typically more than three are used. Once constructed, the WLF equation allows for the est ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymers
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'', meani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time–temperature Superposition
The time–temperature superposition principle is a concept in polymer physics and in the physics of glass-forming liquids. This superposition principle is used to determine temperature-dependent mechanical properties of linear viscoelastic materials from known properties at a reference temperature. The elastic moduli of typical amorphous polymers increase with loading rate but decrease when the temperature is increased.Experiments that determine the mechanical properties of polymers often use periodic loading. For such situations, the loading rate is related to the frequency of the applied load. Curves of the instantaneous modulus as a function of time do not change shape as the temperature is changed but appear only to shift left or right. This implies that a master curve at a given temperature can be used as the reference to predict curves at various temperatures by applying a shift operation. The time-temperature superposition principle of linear viscoelasticity is based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yahweh
Yahweh *''Yahwe'', was the national god of ancient Israel and Judah. The origins of his worship reach at least to the early Iron Age, and likely to the Late Bronze Age if not somewhat earlier, and in the oldest biblical literature he possesses attributes typically ascribed to weather and war deities, fructifying the land and leading the heavenly army against Israel's enemies. The early Israelites were polytheistic and worshipped Yahweh alongside a variety of Canaanite gods and goddesses, including El, Asherah and Baal. In later centuries, El and Yahweh became conflated and El-linked epithets such as El Shaddai came to be applied to Yahweh alone, and other gods and goddesses such as Baal and Asherah were absorbed into Yahwist religion. Towards the end of the Babylonian captivity, the very existence of foreign gods was denied, and Yahweh was proclaimed as the creator of the cosmos and the one true God of all the world, giving birth to Judaism, which has 14–15 mill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Divine Countenance
The divine countenance is the face of God. The concept has special significance in the Abrahamic religions. In Islam Islam considers God to be beyond ordinary vision as the Quran states that "Sights cannot attain him; he can attain sights", but other verses indicate that he would be visible in the hereafter. The Quran makes many references to the face of God but its use of the Arabic word for a physical face — ''wajh'' — is symbolic and is used to refer to God's presence which, in Islam, is everywhere: "wherever you turn, there is the face of God". In Judaism and Christianity In Judaism and Christianity, the concept is the manifestation of God rather than a remote immanence or delegation of an angel, even though a mortal would not be able to gaze directly upon him. In Jewish mysticism, it is traditionally believed that even the angels who attend him cannot endure seeing the divine countenance directly. Where there are references to visionary encounters, these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deborah
According to the Book of Judges, Deborah ( he, דְּבוֹרָה, ''Dəḇōrā'', " bee") was a prophetess of the God of the Israelites, the fourth Judge of pre-monarchic Israel and the only female judge mentioned in the Bible. Many scholars contend that the phrase, "a woman of Lappidot", as translated from biblical Hebrew in Judges 4:4 denotes her marital status as the wife of Lappidot.Van Wijk-Bos, Johanna WH. ''The End of the Beginning: Joshua and Judges''. Wm. B. Eerdmans Publishing, 2019. Alternatively, "lappid" translates as "torch" or "lightning", therefore the phrase, "woman of Lappidot" could be referencing Deborah as a "fiery woman." Deborah told Barak, an Israelite general from Kedesh in Naphtali, that God commanded him to lead an attack against the forces of Jabin king of Canaan and his military commander Sisera (Judges 4:6–7); the entire narrative is recounted in chapter 4. Judges chapter 5 gives the same story in poetic form. This passage, often called ''Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheology
Rheology (; ) is the study of the flow of matter, primarily in a fluid ( liquid or gas) state, but also as "soft solids" or solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an applied force. Rheology is a branch of physics, and it is the science that deals with the deformation and flow of materials, both solids and liquids.W. R. Schowalter (1978) Mechanics of Non-Newtonian Fluids Pergamon The term ''rheology'' was coined by Eugene C. Bingham, a professor at Lafayette College, in 1920, from a suggestion by a colleague, Markus Reiner.The Deborah Number The term was inspired by the of |
Bible
The Bible (from Koine Greek , , 'the books') is a collection of religious texts or scriptures that are held to be sacred in Christianity, Judaism, Samaritanism, and many other religions. The Bible is an anthologya compilation of texts of a variety of forms originally written in Hebrew, Aramaic, and Koine Greek. These texts include instructions, stories, poetry, and prophecies, among other genres. The collection of materials that are accepted as part of the Bible by a particular religious tradition or community is called a biblical canon. Believers in the Bible generally consider it to be a product of divine inspiration, but the way they understand what that means and interpret the text can vary. The religious texts were compiled by different religious communities into various official collections. The earliest contained the first five books of the Bible. It is called the Torah in Hebrew and the Pentateuch (meaning ''five books'') in Greek; the second oldest part was a coll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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