Influence of Organic Montmorillonite Orientation on Flame Retardancy of HIPS/OMMT Nanocomposite

2011 ◽  
Vol 332-334 ◽  
pp. 1803-1806 ◽  
Author(s):  
Mao Juan Bai ◽  
Jun Zhang

The different organic montmorillonite (OMMT) orientation HIPS/OMMT nanocomposites were prepared through the melting intercalated method and second produce. The flame retardancy of the two composites was evaluated by the Cone calorimeter. The structure of burnt residues was observed by digital camera and scanning electron microscope (SEM). The experimental results show that the Heat Release Rate (HRR) and Mass Loss Rate (MLR) for horizontal orientation HIPS/OMMT nanocomposites are lowed in comparison with the vertical orientation composite. The burnt residue of horizontal orientation HIPS/OMMT nanocomposites has a continuous skin layer and three-dimensional texture cellular layer under the skin layer after burning. This kind of structure of char residues has a great effect on the flame retardancy of the composites. While vertical HIPS/OMMT nanocomposites do not formed the continuous skin layer, and the voids in char layer are vertical, which provide the passage for flammable gas, and its flame retardancy is not good.

1997 ◽  
Vol 106 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Akihiro Ikui ◽  
Masaharu Sudo ◽  
Isamu Sando ◽  
Shuji Fujita

Postnatal developmental relationships in human ears were studied by a computer-aided three-dimensional reconstruction and measurement method. We measured the angle, in reference to the horizontal plane, between the tympanic annulus, the oval window, and the internal auditory canal (IAC) in 20 normal temporal bones obtained from individuals between 1 day old and 76 years old. The horizontal plane was defined as the plane sloped 30° infero-anteriorly from the plane of the horizontal canal in each specimen. The plane of the tympanic annulus changed from a nearly horizontal orientation (34.2° from the horizontal plane) in neonates to a more vertical orientation (63.3° from the horizontal plane) in adults. The tympanic annulus and oval window planes remained at the same angle to each other (11.9° ± 5.1°) throughout postnatal development, as did the plane of the tympanic annulus and the LAC (68.6° ± 5.3°). These findings have implications for ear surgeons, especially those operating on young children.


Author(s):  
Sidney D’Mello ◽  
Eric Mathews ◽  
Lee McCauley ◽  
James Markham

We studied the characteristics of four commercially available RFID tags such as their orientation on an asset and their position in a three dimensional real world environment to obtain comprehensive data to substantiate a baseline for the use of RFID technology in a diverse supply chain management setting. Using RFID tags manufactured by four different vendors and a GHz Transverse Electromagnetic (GTEM) cell, in which an approximately constant electromagnetic (EM) field was maintained, we characterized the tags based on horizontal and vertical orientation on a simulated asset. With these baseline characteristics determined, we moved two of the four tags through a real world environment in three dimensions using an industrial robotic system to determine the effect of asset position in relation to the reader on tag readability. Combining the data collected over these two studies, we provide a rich analysis of the feasibility of asset tracking in a real world supply chain, where there would likely be multiple tag types. We offer fine grained analyses of the tag types and make recommendations for diverse supply chain asset tracking.


Perception ◽  
2021 ◽  
pp. 030100662110065
Author(s):  
Klaus Landwehr

The Oppel–Kundt illusion consists in the overestimation of the length of filled versus empty extents. Two experiments explored its relation to the horizontal-vertical illusion, which consists in the overestimation of the length of vertical versus horizontal extents, and to the oblique effect, which consists in poorer discriminative sensitivity for obliquely as opposed to horizontally or vertically oriented stimuli. For Experiment 1, Kundt’s (1863) original stimulus was rotated in steps of 45° full circle around 360°. For Experiment 2, one part of the stimulus remained at a horizontal or vertical orientation, whereas the other part was tilted 45° or 90°. The Oppel–Kundt illusion was at its maximum at a horizontal orientation of the stimulus. The illusion was strongly attenuated with L-type figures when the vertical part was empty, but not enhanced when this part was filled, suggesting that the horizontal-vertical illusion only acts on nontextured extents. There was no oblique effect.


2021 ◽  
pp. 1-13
Author(s):  
Melek Deniz Paker ◽  
Murat Cinar

Abstract A significant portion of world oil reserves reside in naturally fractured reservoirs and a considerable amount of these resources includes heavy oil and bitumen. Thermal enhanced oil recovery methods (EOR) are mostly applied in heavy oil reservoirs to improve oil recovery. In situ combustion (/SC) is one of the thermal EOR methods that could be applicable in a variety of reservoirs. Unlike steam, heat is generated in situ due to the injection of air or oxygen enriched air into a reservoir. Energy is provided by multi-step reactions between oxygen and the fuel at particular temperatures underground. This method upgrades the oil in situ while the heaviest fraction of the oil is burned during the process. The application of /SC in fractured reservoirs is challenging since the injected air would flow through the fracture and a small portion of oil in the/near fracture would react with the injected air. Only a few researchers have studied /SC in fractured or high permeability contrast systems experimentally. For in situ combustion to be applied in fractured systems in an efficient way, the underlying mechanism needs to be understood. In this study, the major focus is permeability variation that is the most prominent feature of fractured systems. The effect of orientation and width of the region with higher permeability on the sustainability of front propagation are studied. The contrast in permeability was experimentally simulated with sand of different particle size. These higher permeability regions are analogous to fractures within a naturally fractured rock. Several /SC tests with sand-pack were carried out to obtain a better understanding of the effect of horizontal vertical, and combined (both vertical and horizontal) orientation of the high permeability region with respect to airflow to investigate the conditions that are required for a self-sustained front propagation and to understand the fundamental behavior. Within the experimental conditions of the study, the test results showed that combustion front propagated faster in the higher permeability region. In addition, horizontal orientation almost had no effect on the sustainability of the front; however, it affected oxygen consumption, temperature, and velocity of the front. On the contrary, the vertical orientation of the higher permeability region had a profound effect on the sustainability of the combustion front. The combustion behavior was poorer for the tests with vertical orientation, yet the produced oil AP/ gravity was higher. Based on the experimental results a mechanism has been proposed to explain the behavior of combustion front in systems with high permeability contrast.


Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 906 ◽  
Author(s):  
Chunjing Zhang ◽  
Bo Shuai ◽  
Xuefeng Zhang ◽  
Xinxin Hu ◽  
Hui Zhang ◽  
...  

Flexibility, stretchability, and flame retardancy are of ever increasing importance in constructing grouting materials. Herein, a simple and effective strategy to make organic-inorganic composite grouting material in a “flexible, stretchable, and flame retardant” way was based on the excellent synergistic interactions among polyurethane prepolymer, red mud, polyethylene glycol, and trimethylolpropane. The resultant polyurethane/red mud composite grouting material with three-dimensional network structure presented a favorable flexibility, desirable compressive strength of 29.2 MPa at 50% compression state, and a good elongation at 15.1%. The grouting material was mainly composed of amorphous polyurethane and crystalline red mud, and its probable formation mechanism was reaction of prepolymer with H2O, polyethylene glycol and trimethylolpropane under vigorous stirring in the presence of catalyst. Furthermore, the grouting material possessed favorable thermal stability, flame retardancy and repairment performance for roadway cracks. This work may open a simple and convenient avenue for the massive engineering application of red mud and preparation of flexible organic-inorganic hybrid grouting material.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Na Liu

Objective. To explore the application of 3D image technology in motor and sensory nerve classification. Methods. A total of 200 sections of the 5cm-long popliteal fossa peroneal nerve from adult volunteers were cut and frozen. The slices were 10 m thick, and the interval between the slices was 0.25 mm. Acetylcholinesterase histochemical staining was used to observe the changes of nerve bundles under the microscope. The stained sections were transformed into digital images by the digital camera system, and the images were stitched to obtain a two-dimensional panoramic image 100 times magnified. The properties of the functional bundles were manually judged. Using Amira 3.1 three‐dimensional reconstruction software to realize the three-dimensional reconstruction and visualization of nerve can not only accurately perceive the complex three-dimensional surface structure of nerve, but also arbitrarily display, rotate, scale, and segment the three-dimensional structure inside nerve, and carry out three-dimensional measurement in time. It has made preliminary achievements in brachial plexus, lumbosacral plexus, neural stem functional bundle (group), and intramuscular nerve routing and distribution, including the regeneration process of sensory nerve and three-dimensional reconstruction and visualization of composite tissue containing sensory nerve. Conclusion. Based on histology and computer technology, the functional band of short peroneal nerve can be reconstructed in 3D, which provides a feasible basis for the three-dimensional reconstruction of the functional band of the long peripheral nerve.


2021 ◽  
Vol 13 (1) ◽  
pp. 80-87
Author(s):  
Minghao Li ◽  
Yu Li

Flame retardants are widely used in many materials and products, and there is a pressing need to enhance the performance of flame retardants while lowering their toxicity. In this paper, using polychlorinated biphenyl flame retardants as an example, a three-dimensional quantitative structure-double-activity relationship (3D-QSA2R) model, with the double activities of flame retardancy and toxicity, was constructed by introducing a vector normalized method to achieve the goal of environmental risk management and control the sources of chemicals. The results showed that the 3D-QSA2R model has good robustness and strong predictive ability. PCB-209 was used as a target molecule for the contour map analysis and molecular modification. The comprehensive values (C) of six novel PCB-209 molecules were increased by up to 53.61%. The physical and chemical parameters (frequency and Gibbs free energy), functional properties (stability and insulation) and the other three POP properties of the novel PCB-209 molecules showed that the Cl atom substitution reaction of PCB209 molecules could occur and exist stably in the environment. With improvement in stability, the insulation of six novel PCB-209 molecules was not influenced after modification, and the environmental persistence, bioconcentration and long-distance migration of six novel PCB-209 molecules were increased up to 99.47%, 15.29% and 100.9%, respectively. The flame retardancy and toxicity of the new molecules were verified by Gaussian software and the EPI database, respectively. The single activity verification values of flame retardancy and toxicity followed the trend of C values predicted by the double-activity 3D-QSA2R model established in this paper. The ratio between the two single activities of the new PCB-209 molecule generally conformed to the weight setting, which satisfies the purpose of setting the weight as the main way to improve the efficacy of flame retardants.


2019 ◽  
pp. 089270571986940
Author(s):  
Chuigen Guo ◽  
Ran Chen ◽  
Liping Li

The main aim of this study was to evaluate the thermal degradation and flame retardancy of straw flour (SF)-polypropylene (PP) composites and wood flour (WF)-PP composites. Biomass silica exists in SF, despite only 18 wt% loading of ammonium polyphosphate (APP); the APP in combination with biomass silica can effectively improve the flame retardancy on total heat release, heat release rate (HRR), mass loss rate, time to ignition (TTI), and limited oxygen index; it can obtain UL-94 V-0 rating, reduce the average and peak HRR by 44% and 41%, respectively, and increase the TTI by 8%. It attributes to the interaction effect between biomass silica in SF and APP, which more effectively enhances the thermal stability of the SF/PP/APP composites at high temperature and increases the char residue. The silica could form an intercalated network in char structure and then boost the physical integrity. The enhanced physical integrity and thermal stability lead to an effectively synergetic effect on flame retardancy of SF/PP/APP composites.


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