Investigations on the thermo-physical properties of nanofluid-based carbon nanofibers under modified testing conditions

Rod shaped carbon nanofibers with 1wt%, 3wt% and 5wt% of iron catalyst loadings are developed by Chemical Vapour Deposition (CVD) and the morphology of the carbon nanofibers are characterized. Nanofluids are prepared by dispersing 0.5wt% of carbon nanofiber in the mixture of Sodium Dodecyl Sulfate (SDS) and deionized water to measure the thermal conductivity at varying temperature conditions. The results show that the thermal conductivity of nanofluid-based carbon nanofiber decreases with the increment in catalyst loading. The morphology examination indicates an increment in the diameter of carbon nanofiber during catalyst loading. Further surface area study for the nanofibers, based on nitrogen absorption analysis, confirms the possible mechanisms that scale down the thermal transport in nanofluid

How electromyography readings from the human forearm are made cryptic, trivial, or non-trivial information for use in synthetic systems

The success of reading potentials generating from human muscle activities is evident that proves that the human body’s neural system is naturally electronics. Now, modern engineering is accepting it as one field of engineering science. Due to this, the concept of a cyborg is beginning to realize as products such as exoskeletons and neuroprostheses. The object of this work, however, is to view from a different perspective as to how this is beneficial to the functions beyond the mentality of today’s applications. We hypothesized that the recorded potentials from muscle activities may be regarded similar as to the signals that jump between synapses in the biological neurons. We suggest that these signals, instead of mere electrical in nature, their waveforms might include emotion characteristics from uniquely combined muscle activities and feeling. The system codes the signals where the newly created information may be made cryptic, trivial, or nontrivial depending on how they are going to be utilized in the synthetic systems. So that the artificial system could sense, for instance, the emotion of the human host

Review on EMG Acquisition and Classification Techniques: Towards Zero Retraining in the Influence of User and Arm Position Independence

The surface electromyogram (EMG) is widely studied and applied in machine control. Recent methods of classifying hand gestures reported classification rates of over 95%. However, the majority of the studies made were performed on a single user, focusing solely on the gesture classification. These studies are restrictive in practical sense: either focusing on just gestures, multi-user compatibility, or rotation independence. The variations in EMG signals due to these conditions present a challenge to the practical application of EMG devices, often requiring repetitious training per application. To the best of our knowledge, there is little comprehensive review of works done in EMG classification in the combined influence of user-independence, rotation and hand exchange. Therefore, in this paper we present a review of works related to the practical issues of EMG with a focus on the EMG placement, and recent acquisition and computing techniques to reduce training. First, we provided an overview of existing electrode placement schemes. Secondly, we compared the techniques and results of single-subject against multi-subject, multi-position settings. As a conclusion, the study of EMG classification in this direction is relatively new. However the results are encouraging and strongly indicate that EMG classification in a broad range of people and tolerance towards arm orientation is possible, and can pave way for more flexible EMG devices

The Classification of EMG Signals with Zero Retraining in the Influence of User and Rotation Independence

The surface electromyogram (EMG) contains information directly related to muscle contraction and modern classification techniques can obtain near-zero error when identifying various gestures over the forearm. However, good results come at a compromise over the ease of use. Once the EMG classifier trained on a user is changed, the accuracy rate will be greatly reduced. Furthermore, changing the position of the forearm also causes drop in accuracy rate. Acknowledging the limitations of EMG classification, this study aims to investigate the EMG signals based on the gestures, and evaluate if there are any gestures which are inherently robust to these variations. The EMG of forearm gestures have been classified in the combined influence user independence, rotation independence and hand exchange independence. Experiment results on 20 participants indicated that truly independent classification can be achieved for most forearm gestures (up to 100%) in some arm positions. Hand exchange is also not feasible as the study has shown that the data field for both hands are fairly different. Out of the nine gestures under study, only the wrist extension was found to be truly independent of all the influences

Nanofluid-based Nanocarbons An Investigation of Thermal Conductivity Performance

This paper presents a study of thermal conductivity performance, using a nanofluid-based nanocarbon formulate, with three different types of nanocarbons. NC300, NC200, and commercial carbon nanotube (CNT)were used together with Sodium Dodecyl Sulphate (SDS) as a dispersant, and deionized water as a solvent. A weighted ratio of the nanocarbons (0.4 - 1.0wt%) was set-up and the thermal conductivity was measured at 6°C, 25°C, and 45°C using a KD2 Pro thermal properties analyser. The results showed that NC300 with 1wt% of nanocarbons at 45°C gave the highest improvement of almost 30%, compared to deionized water. Meanwhile, the best nanofluid, based on prepared nanocarbons (NC200) and commercial CNT, showed improvement of more than 9% and 12%, respectively, with the addition of 0.6wt% nanocarbons at 45°C. Morphology analysis using electron microscopy, revealed the structural properties of the nanocarbons. NC300 showed a loose CNT with an average diameter of 70-150nm. NC200 are supported by nanocarbons with an average diameter of 10- 30nm. Meanwhile, the commercial CNT showed a similar characteristic to that of NC300. Even though NC200 had the smallest diameter of all nanocarbons, (which should provide the highest surface area), the larger sizes of the activated carbons, as a nanocarbon support, are expected to reduce thermal conductivity performance

The Influence Of Pd Nanoparticle Size On Pd/TiO2 Catalysts For Cinnamaldehyde Hydrogenation Reaction

Palladium nanoparticles (PdNP) supported onto the anatase phase of TiO2 were successfully synthesised using a colloidal method. This synthesis method involved the reduction of K2PdCl4 solution by NaBH4 at different temperatures (1, 25, 50, 75oC) and stabilised with PVA ligand. Transmission electron microscope (TEM) was used to determine the particle size of PdNP on the TiO2. Colloidal synthesis at 1oC and 25oC produced PdNP with less than a 3 nm diameter, whereas when the synthesis temperatures were higher than 25oC, PdNP were produced with a size larger than 4 nm. The catalytic activity of Pd/TiO2 was significantly improved when palladium (Pd) was produced at 1oC with high selectivity towards the hydrogenation of cinnamaldehyde to hydrocinnamaldehyde. The conversion and selectivity trends from the cinnamaldehyde hydrogenation reaction demonstrated the influence of Pd nanoparticle size to provide active sites for the reduction of C=C and C=O bonds. Pd with a diameter of 2.58 nm favoured hydrogenation of C=C bond to produce high selectivity towards hydrocinnamaldehyde, meanwhile a large Pd diameter > 4 nm allowed simultaneaous reduction of C=C and C=O bonds to give comparable selectivity between hydrocinnamaldehyde and hydrocinnamylalcohol

Carbon Nanotubes-Based Sensor For Ammonia Gas Detection – An Overview.

A sensitive, selective and reliable sensing techniques for ammonia (NH3) gas detection have been highly demanded since NH3 is both a commonly utilized gas in various industrial sectors, and considered as a toxic and caustic agent that can threat human health and environment at a certain level of concentrations. In this article, a brief on the fundamental working principles of sensor specifications of the analytes detection techniques relying has been reviewed. Furthermore, the mechanism of NH3 detection and recent progress in the development of advanced carbon nanotubes (CNTs)-based NH3 gas sensors, and their performance towards the hybridization with the conductive polymers was comprehensively reviewed and summarized. Finally, the future outlook for the development of high performance NH3 sensors was presented in the conclusions part

Small Scale Hydro Turbines For Sustainable Rural Electrification Program

Hydropower is one of the world leading green alternative energy to produce electricity besides solar and wind energy. Most potential sites for large hydropower scheme in Peninsular Malaysia have been explored. Due to cabling cost and geographical constraints rural electrification program requires in-situ application which make small hydropower scheme more favourable choice. This run-of-river scheme is environmental friendly as no dam is required. Potential locations in Malaysia have been suggested for small hydro turbine applications, which are ideal for eco-friendly tourist industry and remote power supply. The two such sites are Kg. Tual, Raub, Pahang and Gunung Ledang, Tangkak, Johor. The preliminary studies have been conducted at both locations to select suitable hydro turbine based on their head and water flow rate. Altimeter and water velocity probe are used for data collection. As each location is unique, the correct data are needed to estimate the power production and the turbine type. Kg. Tual scheme is found capable of producing 266.99 kW with cost of energy of RM0.017 per kWh by using Pelton or Turgo turbine. However, Gunung Ledang site is suitable of using Kaplan or crossflow turbine as it is able of producing only 4.75 kW at a cost of RM0.159 per kWh

Composites Based On Conductive Polymer With Carbon Nanotubes In DMMP Gas Sensors – An Overview

A number of recent terrorist attacks make it clear that rapid response, high sensitivity and stability are essential in the development of chemical sensors for the detection of chemical warfare agents. Nerve agent sarin [2-(fluoro-methyl-phosphoryl) oxypropane] is an organophosphate (OP) compound that is recognized as one of the most toxic chemical warfare agents. Considering sarin’s high toxicity, being odorless and colorless, dimethyl methylphosphonate (DMMP) is widely used as its simulant in the laboratory because of its similar chemical structure and much lower toxicity. Thus, this review serves to introduce the development of a variety of fabricated chemical sensors as potential sensing materials for the detection of DMMP in recent years. Furthermore, the research and application of carbon nanotubes in DMMP polymer sensors, their sensitivity and limitation are highlighted. For sorption-based sensors, active materials play crucial roles in improving the integral performances of sensors. The novel active materials providing hydrogen-bonds between the polymers and carbon nanotubes are the main focus in this review

Kereaktifan Dan Pencirian Mangkin Co(II)-Dop Sno2 Dan Ni(II)/Co(II)-Dop Sno2 Menggunakan Spektroskopi Pembelauan Sinar-X (XRD) Dan Spektroskopi Fotoelektron Sinar-X (XPS)

Oksida timah (IV) telah dikenalpasti sebagai mangkin yang berpotensi dalam rawatan emisi gas-gas toksik daripada kenderaan bermotor dan aktiviti industri. Kehadiran oksida logam daripada kumpulan peralihan baris pertama sebagai bahan pendop boleh meningkatkan keupayaan pemangkinnya. Dalam kajian ini, mangkin Co(ll)-dop Sn02 (30:70) dan Ni(II)Co(ll) -dop SnO2 (0. 10:29.97:69.93) disediakan mengunakan kaedah modifikasi sol-gel dengan variasi suhu pengkalsinan yang pelbagai. Mangkin Co(ll)-dop SnO2, yang dikalsinkan pada suhu 400°C dan Ni(ll)/Co(II)-dop SnO2 pada suhu pengkalsinan 600°C didapati masing-masing memberikan aktiviti pemangkinan yang terbaik iaitu T100(CO)=l75°C dan T100(CO)=I50°C berbanding mangkin komersil, Pt/AI2O3 [T100(CO)=200°C]. Kajian fizikal bagi melihat transformasi struktur dan pengenalpastian sepsis pada permukaan mangkin ini dilakukan menggunakan Spektroskopi Pembelauan Sinar -X (XRD) dan Spektroskopi Fotoelektron Sinar –X (XPS). Analisis XRD mcnggambarkan kehadiran fasa SnO2 tetragonal dan Co3O4 kubik yang bertindak sebagai tapak aktif dalam pengoksidaan pemangkinan. Kewujudan oksida kobalt (campuran keadaan pengoksidaan +2 dan +3) dan kehadiran campuran spesis Co3+ dan Co2+ -O didapati turut menyumbang kepada pengoksidaan gas karbon monoksida (CO) yang baik seperti disahkan daripada analisis XP