• Title/Summary/Keyword: Papyrus

Search Result 14, Processing Time 0.019 seconds

Papyrus reinforced poly(L-lactic acid) composite

  • Nishino, Takashi;Hirao, Koichi;Kotera, Masaru
    • Advanced Composite Materials
    • /
    • v.16 no.4
    • /
    • pp.259-267
    • /
    • 2007
  • Mechanical reinforcement of an all-sustainable composite, composed of papyrus stem-milled particles as reinforcement and poly-L-lactic acid (PLLA) resin as matrix, was investigated. The papyrus particles (average diameter of $70{\mu}m$) could be well dispersed in PLLA resin up to 50 wt% without any surface modification. Young's modulus of the composite was 4.2 GPa at 50 wt% of the papyrus content. This is a two-fold increment in modulus as compared to that of the PLLA matrix. The tensile strength of the composite was almost constant around 48 MPa irrespective of the papyrus content. Temperature dependence of the storage modulus demonstrated that the incorporation of papyrus restricts the large drop in the modulus above the glass transition of PLLA.

Controversial History of Pi in Ancient Egypt, Old Babylonia, and Ancient Greek Mathematics (고대 이집트, 고바빌로니아, 고대 그리스 수학에 나타난 원주율 논쟁)

  • Park, Jeanam
    • Journal for History of Mathematics
    • /
    • v.33 no.4
    • /
    • pp.223-236
    • /
    • 2020
  • We examine how the formulas of the area and the circumference of a circle related to pi in the ancient Egyptian and the Old Babylonian fields of mathematics have been controversial. In particular, the Great Pyramid of Khufu, Ahmes Papyrus Problem 48 and Moscow Mathematical Papyrus Problem 10 have raised extensive controversy over π. We propose the pi-theory of the Great Pyramid of Khufu as a dynamic symmetry based on Euclid's rectangle. In addition, we argue that the ancient Egyptian or Old Babylonian mathematics influenced Solomon's Molten Sea, Plato and Archimedes' pi.

Chemistry, Biology and Natural Products

  • Sankawa, Ushio
    • Proceedings of the Korean Society of Applied Pharmacology
    • /
    • 1998.11a
    • /
    • pp.22-26
    • /
    • 1998
  • The medicinal plants have been used as drugs for thousands of years and many of them are used in traditional medicines. How long are these medicinal plants used as drugs\ulcorner Ebers papyrus (BC 1550) is one of the oldest documents which described more than 700 kinds of herbal drugs. Some of herbal medicines described in the papyrus are familiar and ‘Opium’ is a good example. Some of the drugs described in the papyrus are hardly recognized as drugs by the standard of present day. We can trace back the history of medicinal plants from quite different approach. The investigations on group behavior of chimpanzees in Africa by ‘The Primate Institute of Kyoto University’ has revealed that chimpanzees suffered illness take specific plants which are not taken as daily food stuff. The chemical analysis clarified that the plants contain very bitter constituents and suggested that chimpanzees take medicinal plants to cure their illness. It is worth to note that young chimpanzees just learn what elder ones take when they suffer illness, but elders never teach to their children! It is no doubt that the chimpanzee's medicinal plants were found by random, and try and error screening. The medicinal plants found in this study have been used as herbal medicines by the peoples in the region.

  • PDF

Squaring the Circle and Recognizing Right Triangles of Ancient Egyptians (고대 이집트인들의 원의 구적과 직각삼각형의 인식)

  • Park, Mingu;Park, Jeanam;Hong, Kyounghee
    • Journal for History of Mathematics
    • /
    • v.30 no.4
    • /
    • pp.221-232
    • /
    • 2017
  • In this paper, we discuss how ancient Egyptians find out the area of the circle based on $\ll$Ahmose Papyrus$\gg$. Vogel and Engels studied the quadrature of the circle, one of the basic concepts of ancient Egyptian mathematics. We look closely at the interpretation based on the approximate right triangle of Robins and Shute. As circumstantial evidence for Robbins and Shute's hypothesis, Egyptians prior to the 12th dynasty considered the perception of a right triangle as examples of 'simultaneous equation', 'unit of length', 'unit of slope', 'Egyptian triple', and 'right triangles transfer to Greece'. Finally, we present a method to utilize the squaring the circle by ancient Egyptians interpreted by Robbins and Shute as the dynamic symmetry of Hambidge.

THE PAPYRUS CODEX -A SURVEY- (파피러스 코덱스에 관한 고찰)

  • Park Young Sook
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.4
    • /
    • pp.72-85
    • /
    • 1975
  • 일반적으로 파피러스(papyrus)는 4세기에 벨럼(vellum)의 사용으로 그 사용이 대체될 때까지 서양에 있어서 책(冊)의 유일한 재료로서 생각되고 있으며, 또한 파피러스는 두루말이(roll)형태의, 양피지(parchment)는 코덱스(codex) 형태의 도서를 의미하였다고 가정되고 있다. 이 보문(報文)은 문헌조사에 의한 개관으로서, 파피러tm와 코덱스에 대해 각각 서술하였고, 위의 가정을 논했으며, 파피러스 코덱스의 외형에 관하여 기술하였다. 코덱스라는 새로운 형태의 책이 양피지에서부터 시작된 것은 사실이나 두루말이에서부터 코덱스로의 변화가 반드시 도서재료의 변화를 뜻하지는 않는다. 그 최초의 사용시기는 알 수 없으나, 파피러스재료가 코덱스 형태에 차용되었음은 확실하다. 파피러스 코덱스에 대한 참조로서, 84-86년에 쓰여진 마샬(Martial)의 시에서 처음 언급하였으며 카시오도로스 (Cassiodorus)의 저서에 나타난 문귀는 6세기에도 사용되었음을 나타낸다. 확실한 것은 2세기초부터 4세기에 벨럼이 도서의 주재료가 될 때까지 기독교문학 특히 성경에 사용되었음이다. 1897년, 그레코${\cdot}$로망시대의 에집트마을인 옥시링쿠스(Oxyrhnchus)답사에서 그렌휄(Grenfell)과 헌트(Hunt)는 파피러스 책을 처음 발굴하였다. 즉, 200년경에 쓰여진 로기아(Logia;예수교훈집)로서 페이지수가 매겨진 근대도서형태의 단편이었다. 체스터 베이티(Chester Beatty)소장 파피러스는 그 전부가 재료는 파피러스이며, 형태는 코덱스이고, 내용은 기독교문학이다. 이는 파피러스 코덱스가 2세기초부터 기독교도에 치매 사용되어 왔음을 확실하게 말해 준다. 진정한 의미의 도서제본은 파피러스로 만든 코덱스에서 시작되었다. 이는 근대도서와 같이 장(sheet )이나 첩(quire)을 묶어서 제본하였다. 이때의 접는 방법, 배열, 크기 및 종행단(縱行段)에 대해서 기술하였다.

  • PDF

The Ethnobotanical Knowledge on Sedge Plants in Korea (Cyperaceae)

  • Chung, Kyong-Sook;Kang, Shin-Ho
    • Proceedings of the Plant Resources Society of Korea Conference
    • /
    • 2019.10a
    • /
    • pp.20-20
    • /
    • 2019
  • Sedge family is second largest family in the Korean flora with more than 240 taxa, following Aster family (about 300 taxa). Although high species diversity, a very limited number of taxa has been utilized for ethnobotanical usages. In the study, previous researches on Cyperaceae ethnobotanical information are documented and analyzed for future research directions on the taxa. A total number of seven taxa has been used for medicinal, food, and material purposes: Carex boottiana Hook. & Arn., Cyperus amuricus Maxim., Cyperus esculentus L., Cyperus exaltatus Retz., Cyperus rotundus L., Eleocharis kuroguwai Ohwi, and Bolboschoenus maritimus (L.) Palla. Underground parts such as tubers are used with medicinal purpose, and aboveground portions such as leaves and stems provide materials for various tools and foods for people and animals. They are all native to Korea, except C. esculentus, which is introduced from Mediterranean areas for anti-erosion materials. The ethnobotanical value of C. esculentus has been well recognized from ancient times, for example, starch grains in USA (excavations at the Mashantucket Pequot Reservation) and Tiger nut milk (Horchata de chufa in Spain). Among material sources, C. exaltatus has a long history in the Korean peninsula from Three Kingdoms of Korea (57 BC~668 AD). C. rotundus is distributed widely in Asia, Africa, Europe, and America, and utilized for medicines, food, and materials. In addition, Eleocharis kuroguwai is only one taxon utilized for ethnobotanical uses among fifteen Eleocharis Korean native species. The number of species with ethnobotanical uses is small in sedge family, but the family has long been utilized accompanying long human history. Cyperus papyrus L., the source of papyrus paper (Egypt in the Nile Delta), is also a member of sedge family. Sedge family has contributed to human societies in various aspects but, the cultural, botanical, ecological values of family members have been underestimated.

  • PDF

Development of M&S Model for Helicopter Rotor Blades Dynamic Analysis using Modelica (Modelica를 이용한 헬기 로터 블레이드 동적해석 M&S 모델 개발)

  • Park, Joongyong
    • Journal of the Korean Society of Systems Engineering
    • /
    • v.11 no.2
    • /
    • pp.75-83
    • /
    • 2015
  • This paper describes modeling & simulation(M&S) model for dynamic analysis of helicopter rotor blades. Simulation model is developed using Dymola tool which implements the open source language - Modelica. Modelica is appropriate for developing multibody dynamic analysis model. To develop an M&S model efficiently, model based systems engineering(MBSE) is applied. Some diagrams such as requirement diagram, block definition diagram and sequence diagram etc. are drawn to capture the concept of M&S model. This activity is done utilizing the open source tool - Papyrus.

The History of Library Classification before Dewey in Western library (서양의 자료분류법의 발달과정 - 고대에서 해리스까지 -)

  • Kim Myung-Ok
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.25
    • /
    • pp.185-213
    • /
    • 1993
  • This study is on the history of classification in Western library from ancient to Harris(1870), before Dewey. It looks into the classification systems of librarians, bibliographers, booksellers and libraries of that time. One of the earliest was the classification of the clay tablets in the Assyrian library of Assurbanipal. But the earliest recorded system in the papyrus is that which Callimachus(B.C. 310-240) devised for the library at Alexandria. In the medival, the monastry libraries used many classifications. but their libraries were very small. Gesner, Naude, Brunet, Jefferson, Edwards, Harris etc. tried to make a good classification for bibliographies and libraries. Especially Brunet made the scheme based on the French system, and it used on bibliographical classification and shelf classification in the many libraries. In 1859, Edwards made the classification scheme for the public library in the Great Britain. In 1870, Harris made the famous inverted Baconian classification and it strongly influenced the Dewey Decimal Classification.

  • PDF

The Wandering of Classic Manuscripts and Their Return to the Library (고전 필사본 유랑과 도서관으로의 귀환)

  • Hee-Yoon Yoon
    • Journal of Korean Library and Information Science Society
    • /
    • v.53 no.4
    • /
    • pp.1-23
    • /
    • 2022
  • The record is both an palmistry and a fingerprint for human life and world of knowledge. Books, which are synonymous with records, are a channel through which history is traced and a window to savor. And the most primitive form of the book is the classics of ancient Greece and Rome, and the best part is the manuscript. It refers to the original recorded on papyrus, parchment, paper, etc. and the translated and translated copies of them. If we reflect on the long history of knowledge and culture, the classic manuscripts have continued to scatter and collect like a river flowing through time and space due to not only natural disasters, but also artificial cultural vandalism and the bibliocaust. Therefore, this study traced and linked the wandering and library return of classic manuscripts from ancient Greece to the medieval Renaissance period. As a result, dynasties and empires, monarchs and prime ministers, generals and conquerors, nobles and wealthy, clergy and scholars concentrated on collecting and translating classical manuscripts. If the ancient Greek and Roman scholars did not record knowledge and wisdom in papyrus and parchment, the medieval Byzantine and Islamic Empires did not collect, translate and reproduce classics, the book hunters didn't keep track of the classics, the Renaissance humanists did not restore and reinterpret the classics through intellectual exodus, and the historical library did not collect and preserve the classics and their translations, modern people would not have access to classical knowledge. Nevertheless, the tracing of classical manuscripts is an aporia in which many difficulties and contradictions overlap in the tracing of classic manuscripts due to historical flow, geographical wandering, and linguistic transformation. When a new manuscript is discovered and interpreted, correction and supplementation are inevitable, so the pursuit of the wandering and return of the classic manuscripts through follow-up research must be continued.

The Study for the Various Methods for the Volume of Frustum of Pyramid (사각뿔대 부피를 구하는 다양한 방법에 대한 탐구)

  • Yoon, Dae-Won;Kim, Dong-Keun
    • Journal for History of Mathematics
    • /
    • v.23 no.3
    • /
    • pp.91-106
    • /
    • 2010
  • This is the study for various methods for getting the volume of frustum of pyramid. This study will first deal with how the formula of getting the volume of frustum of pyramid has been changed in the history of Mathematics. Secondly, based on the study of 'Prasolov' this study will deal with the calculation method for the volume of frustum of pyramid which was written in the 14th question of 'Moscow Papyrus' and search for the rules of solution for frustum of pyramid in the middle school textbooks. Finally, this study will consider various solutions for the volume of frustum of pyramid and its generalization.