• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.870-877
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• 1998

With impedance spectrum measurements, impedance was studied in the interface between sample solutions for $K^+-ion$ selective PVC membrane electrode containing neutral carriers [dibenzo-18-crown-6 (D18Cr6) and valinomycine (Val)]. Response characteristics of electrode were examined by measuring AC impedance spectra that were resulted from the chemical structure and the content of carrier, variation of plasticizer, membrane thickness, doping of base electrolytes, and concentration variation of sample solution. Transport characteristics of PVC membrane electrode were also studied. It was found that the equivalent circuit for the membrane in $K^+$ solution could be expressed by a series combination of solution resistance and a parallel circuit consisting of the bulk resistance and geometric capacitance of the membrane system. But the charge transfer resistance and Warburg resistance were overlapped a little in the low concentration and low frequency ranges. The carrier, D18Cr6 was best for electrode and impedance characteristics, and ideal electrode characteristics were appeared especially in case of doping of the base electrolyte[potassium tetraphenylborate(TPB)]. The optimum carrier content was about 3.23 wt% in case of D18Cr6 and Val. DBP was best as a plasticizer. As membrane thickness decreased the impedance characteristics was improved, but electrode characteristics were lowered for membrane thickness below the optimum. In the case of D18Cr6, the selectivity coefficients by the mixed solution method for the $K^+$ ion were the order of $NH_4{^+}>Ca^{2+}>Mg^{2+}>Na^+$.

• Journal of the Korean Vacuum Society
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• v.18 no.6
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• pp.459-467
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• 2009

$Cd_2GeSe_4$ and $Cd_2GeSe_4:Co^{2+}$ films were prepared on indium-tin-oxide(ITO)-coated glass substrates by using thermal evaporation. The crystallization was achieved by annealing the as-deposited films in flowing nitrogen. X-ray diffraction spectra showed that the $Cd_2GeSe_4$ and the $Cd_2GeSe_4:Co^{2+}$ films were preferentially grown along the (113) orientation. The crystal structure was rhomohedral(hexagonal) with lattice constants of $a=7.405\;{\AA}$ and $c=36.240\;{\AA}$ for $Cd_2GeSe_4$ and $a=7.43\;{\AA}$ and $c=36.81\;{\AA}$ for $Cd_2GeSe_4:Co^{2+}$ films. From the scanning electron microscope images, the $Cd_2GeSe_4$ and $Cd_2GeSe_4:Co^{2+}$ films were plated, and the grain size increased with increasing annealing temperature. The optical energy band gap, measured at room temperature, of the as-deposited $Cd_2GeSe_4$ films was 1.70 eV and increased to about 1.74 eV and of the as-deposited $Cd_2GeSe_4:Co^{2+}$ films was 1.79 eV and decreased to about 1.74 eV upon annealing in flowing nitrogen at temperatures from $200^{\circ}C$ to $500^{\circ}C$. The dynamical behavior of the charge carriers in the $Cd_2GeSe_4$ and $Cd_2GeSe_4:Co^{2+}$ films were investigated by using the photoinduced discharge characteristics technique.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.1
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• pp.115-157
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• 2013

Some contracting States of the Convention on International Civil Aviation (commonly known as the Chicago Convention) issue FAOC(Foreign AOC and/or Operations Specifications) and conduct various safety audits for the foreign operators. These FAOC and safety audits on the foreign operators are being expanded to other parts of the world. While this trend is the strengthening measure of aviation safety resulting in the reduction of aircraft accident, it is the source of concern from the legal as well as economic perspectives. FAOC of the USA doubly burdens the other contracting States to the Chicago Convention because it is the requirement other than that prescribed by the Chicago Convention of which provisions are faithfully observed by almost all the contracting States. The Chicago Convention in its Article 33 stipulates that each contracting State recognize the validity of the certificates of airworthiness and licenses issued by other contracting States as long as they meet the minimum standards of the ICAO. Consequently, it is submitted that the unilateral action of the USA, China, Mongolia, Australia, and the Philippines issuing the FOAC to the aircraft of other States is against the Convention. It is worry some that this breach of international law is likely to be followed by the European Union which is believed to be in preparation for its own unilateral application. The ICAO established by the Chicago Convention to be in charge of safe and orderly development of the international civil aviation has been in hard work to both upgrade and emphasize the safe operation of aircraft. As the result of these endeavors, it prepared a new Annex 19 to the Chicago Convention with the title of "Safety Management" and with the applicable date 14 November 2013. It is this Annex and other ICAO documents relevant to the safety that the contracting States to the Chicago Convention have to observe. Otherwise, it is the economical burden due to probable delay in issuing the FOAC and bureaucracies combined with many different paperworks and regulations depending on where the aircraft is flown. It is exactly to avoid this type of confusion and waste that the Chicago Convention aimed at when it was adopted in 1944. The State of the operator shall establish a system for both the certification and the continued surveillance of the operator in accordance with ICAO SARPs to ensure that the required standards of operations are maintained. Certainly the operator shall meet and maintain the requirements established by the States in which it operate. The authority of a State stops where the authority of another State intervenes or where the former has yielded its power by an international agreement for the sake of international cooperation. Hence, it is not within the realm of the State to issue FAOC towards foreign operators for the reason that these foreign operators are flying in and out of the State. Furthermore, there are other safety audits such as ICAO USOAP, IATA IOSA, FAA IASA, and EU SAFA that assure the safe operation of the aircraft, but within the limit of their power and in compliance with the ICAO SARPs. If the safety level of any operator is not satisfactory, the operator could be banned to operate in the contracting States with watchful eyes until the ICAO SARPs are met. This time-honoured practice has been applied without any serious problems. Besides, we have the new Annex 19 to strengthen and upgrade with easy reference for contracting States. We don't have no reason to introduce additional burden to the States by unilateral actions of some States. These actions have to be corrected. On the other hand, when it comes to the carriage of the Personal or Pilot Log Book, the Korean regulation requiring it is in contrast with other relevant provisions of USA, USOAP, IOSA, and SAFA. The Chicago Convention requires in its Articles 29 and 34 only the carriage of the Journey Log Book and some other certificates, but do not mention the Personal Log Book at all. Paragraph 5.1.1.1 of Annex 1 to the Chicago Convention even makes it clear that the carriage in the aircraft of the Personal Log Book is not required on international flights. The unique Korean regulation in this regards giving the unnecessary burden to the national flag air carriers has to be lifted at once.