Morphology and properties evolution upon ring-opening polymerization during extrusion of cyclic butylene terephthalate and graphene-related-materials into thermally conductive nanocomposites

In this work, the study of thermal conductivity before and after in-situ ring-opening polymerization of cyclic butylene terephthalate into poly (butylene terephthalate) in presence of graphene-related materials (GRM) is addressed, to gain insight in the modification of nanocomposites morphology upon polymerization. Five types of GRM were used: one type of graphite nanoplatelets, two different grades of reduced graphene oxide (rGO) and the same rGO grades after thermal annealing for 1 hour at 1700{\deg}C under vacuum to reduce their defectiveness. Polymerization of CBT into pCBT, morphology and nanoparticle organization were investigated by means of differential scanning calorimetry, electron microscopy and rheology. Electrical and thermal properties were investigated by means of volumetric resistivity and bulk thermal conductivity measurement. In particular, the reduction of nanoflake aspect ratio during ring-opening polymerization was found to have a detrimental effect on both electrical and thermal conductivities in nanocomposites

Effect of morphology and defectiveness of graphene-related materials on the electrical and thermal conductivity of their polymer nanocomposites

In this work, electrically and thermally conductive poly (butylene terephthalate) nanocomposites were prepared by in-situ ring-opening polymerization of cyclic butylene terephthalate (CBT) in presence of a tin-based catalyst. One type of graphite nanoplatelets (GNP) and two different grades of reduced graphene oxide (rGO) were used. Furthermore, high temperature annealing treatment under vacuum at 1700{\deg}C was carried out on both RGO to reduce their defectiveness and study the correlation between the electrical/thermal properties of the nanocomposites and the nanoflakes structure/defectiveness. The morphology and quality of the nanomaterials were investigated by means of electron microscopy, x-ray photoelectron spectroscopy, thermogravimetry and Raman spectroscopy. Thermal, mechanical and electrical properties of the nanocomposites were investigated by means of rheology, dynamic mechanical thermal analysis, volumetric resistivity and thermal conductivity measurements. Physical properties of nanocomposites were correlated with the structure and defectiveness of nanoflakes, evidencing a strong dependence of properties on nanoflakes structure and defectiveness. In particular, a significant enhancement of both thermal and electrical conductivities was demonstrated upon the reduction of nanoflakes defectiveness

Pelayanan Bus Kampus terhadap Mahasiswa Universitas Riau di Pekanbaru

This study aims to see and find out how the campus bus service to students. The population of this research is Student bus users campuses, research was conducted at the University of Riau Pekanbaru object of study is the Student bus users campus, average per / week as many as 2464 sample of this research is Student bus users campus, method used Quota sampling with consideration average per / day fluctuate, the number of bus stops are in the main, the average bus capacity 3x 90, ability Writer. sample size of this study are 96 students at the University of Riau. Then the data were analyzed using quantitative descriptive. Based on the analysis, it was found that student users Bus dominated by FAPERIKA with percentages26% this is because the farthest distance from the bus ride to reach faculty FAPERIKA and views from the campus bus user forces dominated by force in 2015 with a percentage of 39.58%, this is due to for force generation 2015 is classified as dense lecture schedule, not many peer networks, mostly parents of students have not facilitate private vehicles, therefore the students often use the campus bus for personal use. facilities and infrastructure of the bus to facilities bus by category comfortably as many as 48 people with a percentage of 50%, response facilities stop choosing less comfortable are 72 people with a percentage of 75% due to overcrowding at the shelter, sometimes do not have a place to sit while waiting for the bus to arrive because bus turnaround quite long, and if the rain splash hujan.hal this which causes less comfortable students. We recommend that facilities need to be added/enlarged his stops. for the fleet of bus user states do not need the addition of a fleet of 65 people with a percentage of 67.70%. Student responses to the Operational hour bus stating unfavorable approximately as many as 59 people with a percentage of 61.46%, this is due to a less than optimal operational hours therefore critical operations clock needs to be improved

Effect of processing conditions on the thermal and electrical conductivity of poly (butylene terephthalate) nanocomposites prepared via ring-opening polymerization

Successful preparation of polymer nanocomposites, exploiting graphene-related materials, via melt mixing technology requires precise design, optimization and control of processing. In the present work, the effect of different processing parameters during the preparation of poly (butylene terephthalate) nanocomposites, through ring-opening polymerization of cyclic butylene terephthalate in presence of graphite nanoplatelets (GNP), was thoroughly addressed. Processing temperature (240{\deg}C or 260{\deg}C), extrusion time (5 or 10 minutes) and shear rate (50 or 100 rpm) were varied by means of a full factorial design of experiment approach, leading to the preparation of polybutylene terephthalate/GNP nanocomposite in 8 different processing conditions. Morphology and quality of GNP were investigated by means of electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry and Raman spectroscopy. Molecular weight of the polymer matrix in nanocomposites and nanoflake dispersion were experimentally determined as a function of the different processing conditions. The effect of transformation parameters on electrical and thermal properties was studied by means of electrical and thermal conductivity measurement. Heat and charge transport performance evidenced a clear correlation with the dispersion and fragmentation of the GNP nanoflakes; in particular, gentle processing conditions (low shear rate, short mixing time) turned out to be the most favourable condition to obtain high conductivity values

The Rejection of Techno-Culture in the "Alita Battle Angel" Movie by Robert Rodriguez: An Application of Jean Francois Lyotard’s Postmodernism Theory

This research aimed to describe The Rejection of Technoculture in the Alita: Battle Angel Movie by using Jean Francois Lyotard Theory. This research used the Descriptive Qualitative Method. The source of the data in this research is Alita: Battle Angel Movie directed by Robert Rodriguez that is published in 2019. The data was collected through watching the movie carefully several times, pausing every scene to read the conversation text, screen shooting the image that related, and taking a note about the data. This research is analyzed by identifying characters that represented the Technoculture, Displaying and interpreting the data about Technoculture by using Postmodernism theory by Jean Francois Lyotard Theory and Drawing the conclusion. The result of this research found that Alita, Zapan, Grewishka are characters that represented the Technoculture (Cyborg and Human Relationship and Hedonism) represented in the Alita: Battle Angel Movie through the power of science and technology, individualism, and rationality. The Rejection of Technoculture depicted through the character of Alita that her power is not evolved from technology but originating from the legendary martial art called Punzer Kuntz before her body is combined with Ido's technological tools. Technology is not necessarily having an important role in the human body as described by the heroine character, Alita herself, whose overall strength did not come from technology. Alita in this movie is a parody because she is a robot that humanized herself.  In fact, she shows many aspects of his humanity that humans are busy degrading themselves

Durable graphite oxide nanocoating for high performing flame retarded foams

Recent developments in the design of water-based coatings encompassing platelet-like nanoparticles have clearly demonstrated the flame retardant potential of this approach for open cell flexible foams. However, the relatively high number of deposition steps required and the limited reports on the durability of the deposited coatings to multiple compression cycles currently represent the main constraints to this approach. This paper addresses these limitations by exploiting a few steps deposition procedure to produce coatings with durable flame retardant properties. Graphite oxide, sodium alginate and sodium hexametaphosphate were combined in a continuous protective coating that extends to the complex three-dimensional structure of the foam. The flame retardant properties of the coatings were evaluated before and after 1000 compression cycles. Even after such multiple deformations, the coated foams showed no melt dripping and self-extinguishment during flammability tests, as well as a highly reduced heat release rates (-70%) and total smoke release (-70%) during cone calorimetry tests. Furthermore, the ability to withstand the penetration of an impinging flame focused on one side of the coated foam for more than 5 min was also maintained. These results clearly demonstrate the durability of the coated foams, opening to real life application fields such as transports seats where high levels of flame retardancy must be maintained for long time under frequent mechanical stress

Advances in powder bed fusion 3D printing in drug delivery and healthcare

Powder bed fusion (PBF) is a 3D printing method that selectively consolidates powders into 3D objects using a power source. PBF has various derivatives; selective laser sintering/melting, direct metal laser sintering, electron beam melting and multi-jet fusion. These technologies provide a multitude of benefits that make them well suited for the fabrication of bespoke drug-laden formulations, devices and implants. This includes their superior printing resolution and speed, and ability to produce objects without the need for secondary supports, enabling them to precisely create complex products. Herein, this review article outlines the unique applications of PBF 3D printing, including the main principles underpinning its technologies and highlighting their novel pharmaceutical and biomedical applications. The challenges and shortcomings are also considered, emphasising on their effects on the 3D printed products, whilst providing a forward-thinking view