We observe infrared laser excited photoconductivity from a single carbon nanotube incorporated as the channel of an ambipolar field-effect transistor (FET). Electron−hole pairs are generated within the nanotube molecule, and the carriers are separated by an applied electric field between the source and drain contacts. The photocurrent shows resonances whose energies are in agreement with the energies of exciton states of semiconducting nanotubes of the appropriate diameter. The photocurrent is maximized for photons polarized along the direction of the carbon nanotube. Thus, the nanotube FET acts as a polarized photodetector with a diameter 1000 times smaller than the wavelength of the light it detects and has an estimated quantum efficiency of >10%. A photovoltage is observed when an asymmetric band lineup due to two nonequivalent Schottky barriers or an asymmetric coupling of the gate to the nanotube is present.

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The present authors have previously demonstrated the electrokinetic fabrication of a single-walled carbon nanotube (SWCNT) gas sensor by employing dielectrophoresis. Because this method employs mass-produced SWCNTs, it can realize cheaper and more flexible SWCNT gas sensor fabrication than that based on the on-site synthesis of SWCNTs. In this study, a new protocol was proposed and tested for the separation and enrichment of semiconducting SWCNTs, aiming to improve the SWCNT gas sensor sensitivity. The protocol employed a spin column filled with size-exclusion dextran-based gel beads as well as two surfactants (sodium dodecyl sulfate and sodium deoxycholate), which had different affinities to metallic and semiconducting SWCNTs. The separation and enrichment of the semiconducting SWCNTs were confirmed by measuring their optical and electrical properties. The CNT gas sensor fabricated using enriched semiconducting SWCNTs was highly sensitive to nitrogen dioxide (NO 2 ) gas, -more sensitive by 10 times than that fabricated using the pristine SWCNT mixture.

Masyarakat modern cenderung memakai listrik secara kontinyu. Dan, tergantung dari pemakaian, besaran listrik yang dipakai berubah seiring waktu. Nilai besaran listrik harus berada dalam batasan tertentu agar sistem yang bekerja menggunakan listrik dapat berfungsi dengan baik. Selain itu, teknologi hijau mendorong pemakaian listrik optimal sesuai dengan keperluannya. Tetapi, pengukuran konvensional untuk nilai besaran listrik terpakai tidak efisien, pengecekan dilakukan berkala dan harus ditera langsung pada perangkat pengukur seperti meteran listrik. Dan, pada sistem tenaga listrik yang lebih kompleks seperti sistem tiga fasa dapat terjadi fluktuasi perubahan beban, ketidakseimbangan beban pada tiap fasa, mau pun keadaan abnormal yang terjadi dalam rentang yang singkat. Sehingga, kebutuhan informasi pemakaian besaran listrik waktu nyata diperlukan. Penelitian untuk Dashboard Pengawasan Besaran Listrik Waktu Nyata dilakukan dengan tujuan melakukan pengawasan terhadap besaran listrik terpakai. IoT (Internet of Things) dimanfaatkan untuk mendapatkan data mengenai besaran listrik seperti Tegangan, Arus, Daya, Faktor Daya, dan Energi. IoT kemudian mengirimkan data besaran listrik ke server basis data yang kemudian diakses oleh Dashboard untuk disajikan dalam grafik yang mudah dipahami.

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The increasing frequency of lightning strikes endangers human safety and life. The grounding system was introduced to face the lightning strikes. This research aimed to understand the changes of grounding resistance value using concrete mixed with bentonite and coconut fiber. The research was conducted in the Laboratory of Electrical Engineering, University of Lampung. The research was started from October 2017 to April 2018. This research used the Ufer grounding system. Concretes with (25 x 25 x 30) cm3 in volume were planted at a depth of 50 cm with copper-coated electrodes that were 16 mm in diameter. 4 concrete was produce with different component T1= concrete, 30% bentonite, T2= concrete, 30% bentonite, 1.5% coconut fiber, T3= concrete, 30% bentonite, 0.75% coconut fiber, T4= concrete + 1.5% coconut fiber. The results show that the lowest grounding resistance values were 45.896 Ω on the concrete with bentonite: cement: sand: gravel = 0.3: 0.7: 2: 4. By adding 1.5% coconut fiber, the grounding resistance value is 3.5 times smaller than the grounding resistance values of the soil (161.2 Ω). Adding bentonite and coconut fiber can decrease the grounding resistance values

Electromagnetic interference (EMI) due to lightning strike in Unmanned Aerial Vehicle (UAV) became a critical issue, since it could cause a severe damaged to electronic equipment which was installed in UAV. This paper proposed a method to reduce EMI by creating shield over the body of UAV with aluminum foil with thickness 0.15mm. A standard lightning impulse-voltage generated by impulse generator was delivered to the high voltage (HV) electrode at a particular distance from UAV. Indirect effect of lightning strike was investigated by measuring induced voltage inside the compartment of UAV fuselage during flashover between the HV electrode and UAV. Flashover between the HV electrode and UAV simulated the lightning strike. The result showed that the highest voltage only 1V at UAV compartment when 150kV impulse voltage supplied to the electrode with striking area on the wing. The measured voltage was far below 100V as the insulation level of low voltage equipment inside UAV. Although the direct effect of lightning has created a burning hole on the surface aluminum foil with thickness 0.15mm, the effect was overcome by increasing the thickness to 0.3mm. The application of aluminum foil over the surface of UAV repelled the electromagnetic interference which acted as a Faraday cage. The shielding method was successfully reduced the effect of EMI.