Melt Spinning of the Fine PEEK Filaments

The production of fine filaments using the melt spinning process needs considerable effort. A thermoplastic melt is stretched from the spinneret under a constant take-up speed. The high performance thermoplastic PEEK is solidified in the melt spinning process in a small distance and short time. Therefore, the fine PEEK filaments in the fibre formation zone underwent a high deformation and cooling rate. To make the melt spinning process stable and to produce the fine PEEK filaments, material properties and material behaviour are examined using on-line and off-line measurements. The fibre speed measured using Laser Doppler Anemometry and simultaneous temperature measured using infrared thermography enable both the strain rate and consequently the apparent extensional viscosity to be estimated. This provides the apparent extensional viscosity over the spinning line, which can itself show the structural development of PEEK fibres in the fibre formation zone, i.e. necking and solidification phenomena. The one-dimensional fibre formation model must include both procedural and material parameters. The heat transfer coefficient was estimated using the filament temperature measurement and showed a relatively high contribution of radiation and free convection in comparison to forced convection near the spinneret. The improved model of PEEK fibre formation gave a good agreement to both temperature and speed measurements, and also confirmed the high deformation rate effect on the extensional viscosity, which could be simulated with a properly generalised Newtonian constitutive equation. The end properties of the fibres, such as as-spun filament fineness, orientation (expressed using total birefringence) and total crystallisation (examined using DSC) are investigated in relation to different spinning conditions, i.e. take-up speed, throughput and the draw down ratio. The tensile test diagram results, measuring phenomena such as the elongation at break, tenacity, and the Young modulus of elasticity are also analysed in order to complete the correlation of the above-mentioned spinning conditions to the structural properties of as-spun fine PEEK filaments. The melt spinning of fine PEEK fibres under different spinning conditions is examined with the purpose of finding the optimum take-up speed and throughputs. Other spinning conditions, such as the temperature of melt processing, and the arrangement and diameter of the spinneret holes, are changed in order to make the process more stable. The recommendations for further study can be used to further examine some aspects of this work; however, this work presents a new concept for fine PEEK melt spinning supported by spinnability examinations under different spinning conditions and the improved model of fibre formation, which is also relevant for typical industrial processing applications

Three-Dimensional Technology in the Educational Process and Learning

The need for extraordinary innovation in the field of electronics technology, has also changed the nature of education and the teaching process. On the other hand, as previous research has shown, the highest level of learning is done through the sense of sight. So it is worthy to use visual teaching aids, in order to achieve more, and we can also have it mixed with new technologies and prevent the vision students, to rely on the teachers only. One of these emerging technologies is the three-dimensional visual technology. This technology has a great potential, in most areas, that it has opened its place. The aim of this study is to evaluate the notice and interest of students in their learning process is technology the three-dimensional. The data which is needed; is collected with library research, and methodology of the study is cross-sectional in nature

The Study for the Situation of Higher Education in Today's World and in Other Countries to Help a Good Knowledge Management in Our Country

No doubt the higher education system plays a crucial role in the development of the society. Therefore considering the important role of these institutions in various aspects, to ensure a well quality performance in any of its functions, in order to avoid wasting human and material assets are undeniable necessity. The most important in realization of the solution, is the study and awareness of the situation of higher education in today's world and the use of statistics and experiences of other countries in this course and interpretation of this information. The aim of this study is to investigate the situation of higher education in the today's world in order to help to manage a well knowledge and also to eliminate the challenges associated with the higher education is important. The data which is needed; is collected with library research, and methodology of the study is cross-sectional in nature

CFD MODELLING OF DISPERSION WITHIN RANDOMLY DISTRIBUTED CYLINDER ARRAYS

Vegetation has a significant role in reducing the negative effects of polluted water on natural water bodies. However, a lack of understanding with respect to vegetation-flow interactions may result in poorer performance than expected. The most common vegetation types have been modelled as cylinders by many researchers both in the laboratory and numerical studies. However, experimental studies face practical issues, such as the need for expensive equipment. The quality of the velocity and scalar transport data collected from laboratory setups is also often lower than expected. On the other hand, attempts to model flow and mixing within cylinder arrays using advanced CFD models, e.g. LES, are extremely computationally expensive and cannot be used to produce comparable data to that recorded in laboratory setups. This thesis proposes and validates the use of commercial less-computationally expensive CFD models (RSM models available in ANSYS FLUENT) as a complementary tool. This tool allows cylinder arrays to be modelled at the same scale as laboratory setups, provides high-resolution flow and turbulence data of high accuracy, and in combination with scalar transport modelling, provides estimated mixing coefficients of the same level of accuracy as those observed in laboratory studies. The general modelling methodology is built based on the results of a series of preliminary studies. These include novel studies on estimating the advective zone length and the minimum required mixing reach length necessary to provide the desired accuracy, both presented for the first time, as well a validation of the general methodology. The developed methodology was used to produce a new high-resolution and high-accuracy dataset. The main outcome of this thesis is a very convincing set of evidence that justifies the use of the CFD model as an alternative to traditional lab-based work. A few future studies are suggested to develop a deeper understanding of the processes that control mixing

The use of computer games for education purposes due to the positive potential of such games

The new educational theories are based on the principle that learning process should be based on interests, needs and satisfaction, and motivational. One of the main interests of the child and adult is video games that they play long hours in front of computers and other tools. Using appropriate strategies can take advantage of the game for education purposes. The aim of this study was to investigate the potential and the use of computer games in the world today and to use them for educational purposes. This research demonstrates that despite the positive potential of these Games,Unfortunately in the field of education is not a good use of them

Strawberry root and crown rot disease survey 2005 and 2006 seasons

Reports of unusually high numbers of plant deaths in strawberry crops from growers in Western Australia prompted a survey to identify the cause. Plant and soil samples were taken from a range of growers and runner sources over a two-year period and tested for plant pathogens. Fusarium oxysporum f. sp. fragariae was identified as the predominant pathogen, the first recording of this in Western Australia. Further work is planned to clarify the epidemiology of this pathogen and evaluate suitable methods of control. Patcheshttps://researchlibrary.agric.wa.gov.au/bulletins/1169/thumbnail.jp

PORTA: THE LANGUAGE OF DOORS

In my master design studio, I was asked to imagine what I would say, what would be my story, if I was a door.This is the poem I wrote as an answer to this query: IF I WAS A DOOR Come closer; Let me tell you how painful my loneliness is. Behind this coarse body, stories are hidden. Come closer; Tear the threshold curtains Let me tell you of the woman with henna colored hair Who sat beside me days and years, cried and waited for her son Who went to war years ago. I wonder if she is still there. Dusty alleys of our parish, Children of the street whose voice’s tingles Swept me to far places; to flying Pelican of Golshan garden in Tabas, Alborz Mountains, smell of rain, smell of earth Come closer; let me tell you how beautiful the other side of the world is with these little windows on my skin. Could I be green, like the pines of our garden, Could I have had a platform for every tired traveler to rest and tell me of his journey. Could I have had a doorkeeper to tell these secrets to: Scent of satin, hanging sweetbrier from my brow, secret melody of swallows… Would they not replace me with another: There, that house, that parish is all my memory. This thesis is about the doorway; it is also about threshold, transition, and the in-between. It aims to encourage a more engaged interaction between people and the spaces around them

Comparing the Conventional with Low Dose of Bupivacaine Plus Fentanyl in Spinal Anesthesia on the Neonate Apgar Score in Yazd City

Introduction: Spinal anesthesia is the preferred method of anesthesia in cesarean section, due to less complications. The augmentation of opioids to spinal anesthetics can improve the quality and increase the duration of analgesia. This study aimed to compare the conventional with low dose of bupivacaine plus fentanyl in spinal anesthesia on the neonate Apgar score in elective cesarean section. Methods: The present double-blind randomized clinical trial was conducted on 150 pregnant mothers undergoing cesarean section with the spinal anesthesia during 2017-2018. The mothers were randomly assigned to two groups of 75. The spinal anesthesia was performed in the first group with the injection of 15 mg of 0.5% hyperbaric bupivacaine plus 1 ml of normal saline, and in the second group with the injection of 12.5 mg of 0.5% hyperbaric bupivacaine plus 25 μg of fentanyl. For both groups, 1- and 5-minute neonatal Apgar scores were assessed. Finally, the data were analyzed by SPSS17 software using statistical tests. Results: The mean age of the samples was 30.1±5.19 years with a range of 18-42 years (P-value=0.246). The mean gestational age was 38 weeks, the mean 1-minute Apgar score was 8.88 and the mean 5-minute Apgar score was 9.89. Conclusion: With the augmentation of fentanyl to bupivacaine for spinal anesthesia, the conventional dose can be reduced, which not only reduces the common side effects of Marcainee, but also provides an appropriate level of anesthesia and does not affect the neonatal Apgar score

Bis[4-amino-N-(pyrimidin-2-yl-κN)benzene­sulfonamidato-κN](4,4′-di­methyl-2,2′-bipyridine-κ2 N,N′)cadmium dimethyl­formamide disolvate

In the title compound, [Cd(C10H9N4O2S)2(C12H12N2)]·2C3H7NO, the CdII ion lies on a twofold rotation axis, is six-coordinated by N atoms, and displays a trigonal–prismatic geometry arising from the two sulfadiazinate ligands and one 4,4′-dimethyl-2,2′-bipyridine ligand. Both ligands are bidentate and coordinate via their N atoms. The O and carbonyl C atoms of the dimethyl­formamide mol­ecule show disorder and were modelled with two different orientations and with site occupancies of 0.584 (10):0.416 (10). The geometry around the sulfadiazine S atom is distorted tetra­hedral. The crystal structure involves N—H⋯O hydrogen bonds which link mol­ecules into a three-dimensional network. Weak C—H⋯O hydrogen bonds are also observed