scholarly journals Melt-Mixed PP/MWCNT Composites: Influence of CNT Incorporation Strategy and Matrix Viscosity on Filler Dispersion and Electrical Resistivity

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 189 ◽  
Author(s):  
Petra Pötschke ◽  
Fanny Mothes ◽  
Beate Krause ◽  
Brigitte Voit

Small-scale melt mixing was performed for composites based on polypropylene (PP) and 0.5–7.5 wt % multiwalled carbon nanotubes (MWCNT) to determine if masterbatch (MB) dilution is a more effective form of nanofiller dispersion than direct nanotube incorporation. The methods were compared using composites of five different PP types, each filled with 2 wt % MWCNTs. After the determination of the specific mechanical energy (SME) input in the MB dilution process, the direct-incorporation mixing time was adjusted to achieve comparable SME values. Interestingly, the electrical resistivity of MB-prepared samples with 2 wt % MWCNTs was higher than that of those prepared using direct incorporation—despite their better dispersion—suggesting more pronounced MWCNT shortening in the two-step procedure. In summary, this study on PP suggests that the masterbatch approach is suitable for the dispersion of MWCNTs and holds advantages in nanotube dispersion, albeit at the cost of slightly increased electrical resistivity.

2020 ◽  
Vol 5 (10) ◽  
pp. 1174-1178
Author(s):  
W. A. Akinfiresoye ◽  
A. A. Akintade ◽  
S. A. Fasoyin

The traditional method of using hands to depulp African Locust Bean (ALB) inside a flowing river led to the conception and development of a simple operated 3 kg capacity ALB depulping machine at the Farm Power and Machinery Workshop of Agricultural and Bio-Environmental Engineering, Rufus Giwa Polytechnic, Owo, Ondo State, Nigeria. The depulping machine has the hopper, the depulping unit which has the shaft carrying paddles to beat off the seed from the pulp, the frame, the water reservoir to aid the process and 2.2 kW power unit. ALB of moisture contents 60%, 71% and 78% were depulp at machine speed of 173 rpm. The time taken for each operation to be completed was taken. It was discovered that the machine performance in terms of efficiency and throughput increases as the moisture content of the ALB increases while the specific mechanical energy decreases as the moisture content increases. At moisture content of 78%, the efficiency of the depulping machine was 83%, the throughput was about 236 kg/h and the specific mechanical energy was 122.32 KG/KJ. The cost of the machine was Seventy Eight Thousand Naira (NGN 78,000:00). It is recommended for small and medium ALB farmers.


2016 ◽  
Vol 49 (4) ◽  
pp. 356-367 ◽  
Author(s):  
Paulina Latko ◽  
Mateusz Bielecki ◽  
Rafał Kozera ◽  
Anna Boczkowska

This article describes nanocomposites of triblock copolymer styrene–ethylene/butylene–styrene doping with 5 wt% of multiwalled carbon nanotubes (CNTs) prepared by melt mixing process. The selection of processing temperature was made according to the state of macrodispersion of CNTs within polymer matrix. Afterwards, the relationship between rotational speed, mixing time and electrical conductivity has been noted. It was confirmed that the temperature of 300°C and rotational speed of 100 r/min lead to significant decreasing of CNT agglomerations resulting in high electrical conductivity equal to 8.0 S/m.


2020 ◽  
Vol 3 (1) ◽  
pp. 61
Author(s):  
Kazuhiro Aruga

In this study, two operational methodologies to extract thinned woods were investigated in the Nasunogahara area, Tochigi Prefecture, Japan. Methodology one included manual extraction and light truck transportation. Methodology two included mini-forwarder forwarding and four-ton truck transportation. Furthermore, a newly introduced chipper was investigated. As a result, costs of manual extractions within 10 m and 20 m were JPY942/m3 and JPY1040/m3, respectively. On the other hand, the forwarding cost of the mini-forwarder was JPY499/m3, which was significantly lower than the cost of manual extractions. Transportation costs with light trucks and four-ton trucks were JPY7224/m3 and JPY1298/m3, respectively, with 28 km transportation distances. Chipping operation costs were JPY1036/m3 and JPY1160/m3 with three and two persons, respectively. Finally, the total costs of methodologies one and two from extraction within 20 m to chipping were estimated as JPY9300/m3 and JPY2833/m3, respectively, with 28 km transportation distances and three-person chipping operations (EUR1 = JPY126, as of 12 August 2020).


Author(s):  
Mohammad Istiak Hossain ◽  
Jan I. Markendahl

AbstractSmall-scale commercial rollouts of Cellular-IoT (C-IoT) networks have started globally since last year. However, among the plethora of low power wide area network (LPWAN) technologies, the cost-effectiveness of C-IoT is not certain for IoT service providers, small and greenfield operators. Today, there is no known public framework for the feasibility analysis of IoT communication technologies. Hence, this paper first presents a generic framework to assess the cost structure of cellular and non-cellular LPWAN technologies. Then, we applied the framework in eight deployment scenarios to analyze the prospect of LPWAN technologies like Sigfox, LoRaWAN, NB-IoT, LTE-M, and EC-GSM. We consider the inter-technology interference impact on LoRaWAN and Sigfox scalability. Our results validate that a large rollout with a single technology is not cost-efficient. Also, our analysis suggests the rollout possibility of an IoT communication Technology may not be linear to cost-efficiency.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2263
Author(s):  
Mahmood Ebadian ◽  
Shahab Sokhansanj ◽  
David Lee ◽  
Alyssa Klein ◽  
Lawrence Townley-Smith

In this study, an inter-continental agricultural pellet supply chain is modeled, and the production cost and price of agricultural pellets are estimated and compared against the recent cost and price of wood pellets in the global marketplace. The inter-continental supply chain is verified and validated using an integration of an interactive mapping application and a simulation platform. The integrated model is applied to a case study in which agricultural pellets are produced in six locations in Canada and shipped and discharged at the three major ports in Western Europe. The cost of agricultural pellets in the six locations is estimated to be in the range of EUR 92–95/tonne (CAD 138–142/tonne), which is comparable with the recent cost of wood pellets produced in small-scale pellet plants (EUR 99–109/tonne). The average agricultural pellet price shipped from the six plants to the three ports in Western Europe is estimated to be in a range of EUR 183–204 (CAD 274–305/tonne), 29–42% more expensive that the average recent price of wood pellets (EUR 143/tonne) at the same ports. There are several potential areas in the agricultural pellet supply chains that can reduce the pellet production and distribution costs in the mid and long terms, making them affordable supplement to the existing wood pellet markets. Potential economic activities generated by the production of pellets in farm communities can be significant. The generated annual revenue in the biomass logistics system in all six locations is estimated to be about CAD 21.80 million. In addition, the logistics equipment fleet needs 176 local operators with a potential annual income of CAD 2.18 million.


2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Hirofumi Niiya ◽  
Kenichi Oda ◽  
Daisuke Tsuji ◽  
Hiroaki Katsuragi

Abstract The formation of aggregates consisting of snow, water, and tephra has been reported in small-scale experiments on three-phase flows containing tephra, water, and snow, representing lahars triggered by snowmelt. Such aggregates reduce the mobility of mud flow. However, the formation mechanism of such aggregates under various conditions has not been investigated. To elucidate the formation conditions and mechanical properties of the aggregates, we performed mixing experiments with materials on a rotating table and compression tests on the resulting aggregates with a universal testing machine in a low-temperature room at $$0\,^{\circ }\text {C}$$ 0 ∘ C . From experiments with varying component ratios of the mixture and tephra diameter, the following results were obtained: (i) the aggregate grew rapidly and reached maturity after a mixing time of 5 min; (ii) the mass of aggregates increased with snow concentration, exhibiting an approximately linear relationship; (iii) single aggregates with large mass formed at lower and higher tephra concentrations, whereas multiple aggregates with smaller mass were observed at intermediate concentrations; (iv) the shape of the aggregate satisfied the similarity law for an ellipsoid; (v) the compressive mechanical behavior could be modeled by an empirical nonlinear model. The obtained mechanical properties of the aggregates were independent of the experimental conditions; (vi) scaling analysis based on the Reynolds number and the strength of the aggregates showed that the aggregates cannot form in ice-slurry lahars. Our findings suggest that low-speed lahars containing snow and ice are likely to generate aggregates, but snow and ice in the ice-slurry lahars are dispersed without such aggregates.


2019 ◽  
Vol 11 (8) ◽  
pp. 2400 ◽  
Author(s):  
Karthikeyan Mariappan ◽  
Deyi Zhou

Agriculture is the main sources of income for humans. Likewise, agriculture is the backbone of the Indian economy. In India, Tamil Nadu regional state has a wide range of possibilities to produce all varieties of organic products due to its diverse agro-climatic condition. This research aimed to identify the economics and efficiency of organic farming, and the possibilities to reduce farmers’ suicides in the Tamil Nadu region through the organic agriculture concept. The emphasis was on farmers, producers, researchers, and marketers entering the sustainable economy through organic farming by reducing input cost and high profit in cultivation. A survey was conducted to gather data. One way analysis of variance (ANOVA) has been used to test the hypothesis regards the cost and profit of rice production. The results showed that there was a significant difference in profitability between organic and conventional farming methods. It is very transparent that organic farming is the leading concept of sustainable agricultural development with better organic manures that can improve soil fertility, better yield, less input cost and better return than conventional farming. The study suggests that by reducing the cost of cultivation and get a marginal return through organic farming method to poor and small scale farmers will reduce socio-economic problems such as farmers’ suicides in the future of Indian agriculture.


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