338 resultados para Bundled conductors


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RESUM L'automatització s'utilitza des de fa molts anys, tot i que va començar a agafar la definició que coneixem actualment al voltant dels anys seixanta i setanta, moment en què es comencen a comercialitzar els primers PLC. A partir d'aquí, el seu creixement ha estat exponencial. En aquest sentit, la tecnologia ha anat avançant i ha augmentat els components que la forma, per això a hores d'ara encara no sabem fins on podrà arribar i què aconseguirà. Per a la indústria tot això ha significat l'automatització de processos que fins ara utilitzaven molt mà d'obra, reduint-la dràsticament. Una de les indústries que més s'ha beneficiat de tots aquests avenços ha estat la de l'automoció, concretament les seves grans línies de producció, automatitzades a uns nivells que fins fa poc temps eren impensables. Aquest projecte forma part d'aquesta indústria, no directament per a la construcció de l'automòbil, sinó indirectament, ja que l'empresa per a la qual s'ha fet l'automatització fabrica peces plàstiques per a automòbils. Concretament, unes peces amb uns injerts metàl•lics conductors que es munten a tots els vehicles i s'utilitzen per accionar els neteja vidres dels cotxes. Aquest fet implica que la fabricació i el disseny de la peça sigui curosament vigilat i controlat per al client final, amb uns controls de qualitat extremadament exigents. El funcionament del procés de fabricació es fa a partir d'unes peces de plàstic produïdes per una injectora que es fan passar per unes estacions automatitzades, cada una de les quals fa una acció concreta per aconseguir el muntatge final.

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Mediayhtiöt miettivät keinoja joilla saataisiin lukijat maksamaan myös verkkopalveluihin julkaistavista sisällöistä. Tässä tutkimuksessa selvitettiin tilaajapohjaisen maksullisen verkkopalvelu-mallin soveltuvuutta Talentum Media Oy:lle sekä kehitettiin yritykselle maksavia asiakkaita houkuttelevan sisältötuotteen konsepti. Tutkimuksessa ei ilmennyt syitä, joiden takia yrityksen olisi syytä lykätä maksullisen verkkopalvelun kehittämistä. Perinteistä lehteä ja sen verkkopalvelua ei kannata nähdä toistensa kilpailijoina. Käyttäjät ovat yhä valmiimpia maksamaan sisällöstä verkossa, kun se on järjestelty houkutteleviksi kokonaisuuksiksi ja paketoitu oikein, sekä kun he säästävät aikaa tai vaivaa verkkopalvelun käytöllä. Verkkopalvelun muuntaminen maksulliseksi on kuitenkin suunniteltava erittäin tarkkaan, muuten käyttäjät saattavat siirtyä ilmaisiin palveluihin. Talentumin verkkopalveluiden käyttäjille tehdyn kyselytutkimuksen mukaan yrityksen verkkopalveluiden käyttäjät maksaisivat mieluiten verkkokoulutuksista, erityisraporteista ja tutkivasta journalismista, ammattikirjojen tiivistelmistä, opastavista tietopaketeista, pörssi- ja yritystiedosta sekä näköislehdistä. Tutkimuksessa kehitettiin maksullisen verkkopalvelun konsepti, joka tarjoaa lukijoille itsensä kehittämisen välineitä sekä informaatiota nopeasti ja vaivattomasti heidän haluamaansa aikaan ja valitsemallaan päätelaitteella. Konseptia seuraavan tuotekehityshankkeen tuloksena syntyvästä verkkopalvelusta odotetaan saatavan merkittävää lisäliikevaihtoa yrityksen online-toiminnoille.

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Permanent magnet generators (PMG) represent the cutting edge technology in modern wind mills. The efficiency remains high (over 90%) at partial loads. To improve the machine efficiency even further, every aspect of machine losses has to be analyzed. Additional losses are often given as a certain percentage without providing any detailed information about the actual calculation process; meanwhile, there are many design-dependent losses that have an effect on the total amount of additional losses and that have to be taken into consideration. Additional losses are most often eddy current losses in different parts of the machine. These losses are usually difficult to calculate in the design process. In this doctoral thesis, some additional losses are identified and modeled. Further, suggestions on how to minimize the losses are given. Iron losses can differ significantly between the measured no-load values and the loss values under load. In addition, with embedded magnet rotors, the quadrature-axis armature reaction adds losses to the stator iron by manipulating the harmonic content of the flux. It was, therefore, re-evaluated that in salient pole machines, to minimize the losses and the loss difference between the no-load and load operation, the flux density has to be kept below 1.5 T in the stator yoke, which is the traditional guideline for machine designers. Eddy current losses may occur in the end-winding area and in the support structure of the machine, that is, in the finger plate and the clamping ring. With construction steel, these losses account for 0.08% of the input power of the machine. These losses can be reduced almost to zero by using nonmagnetic stainless steel. In addition, the machine housing may be subjected to eddy current losses if the flux density exceeds 1.5 T in the stator yoke. Winding losses can rise rapidly when high frequencies and 10–15 mm high conductors are used. In general, minimizing the winding losses is simple. For example, it can be done by dividing the conductor into transposed subconductors. However, this comes with the expense of an increase in the DC resistance. In the doctoral thesis, a new method is presented to minimize the winding losses by applying a litz wire with noninsulated strands. The construction is the same as in a normal litz wire but the insulation between the subconductors has been left out. The idea is that the connection is kept weak to prevent harmful eddy currents from flowing. Moreover, the analytical solution for calculating the AC resistance factor of the litz-wire is supplemented by including an end-winding resistance in the analytical solution. A simple measurement device is developed to measure the AC resistance in the windings. In the case of a litz-wire with originally noninsulated strands, vacuum pressure impregnation (VPI) is used to insulate the subconductors. In one of the two cases studied, the VPI affected the AC resistance factor, but in the other case, it did not have any effect. However, more research is needed to determine the effect of the VPI on litz-wire with noninsulated strands. An empirical model is developed to calculate the AC resistance factor of a single-layer formwound winding. The model includes the end-winding length and the number of strands and turns. The end winding includes the circulating current (eddy currents that are traveling through the whole winding between parallel strands) and the main current. The end-winding length also affects the total AC resistance factor.

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Today’s electrical machine technology allows increasing the wind turbine output power by an order of magnitude from the technology that existed only ten years ago. However, it is sometimes argued that high-power direct-drive wind turbine generators will prove to be of limited practical importance because of their relatively large size and weight. The limited space for the generator in a wind turbine application together with the growing use of wind energy pose a challenge for the design engineers who are trying to increase torque without making the generator larger. When it comes to high torque density, the limiting factor in every electrical machine is heat, and if the electrical machine parts exceed their maximum allowable continuous operating temperature, even for a short time, they can suffer permanent damage. Therefore, highly efficient thermal design or cooling methods is needed. One of the promising solutions to enhance heat transfer performances of high-power, low-speed electrical machines is the direct cooling of the windings. This doctoral dissertation proposes a rotor-surface-magnet synchronous generator with a fractional slot nonoverlapping stator winding made of hollow conductors, through which liquid coolant can be passed directly during the application of current in order to increase the convective heat transfer capabilities and reduce the generator mass. This doctoral dissertation focuses on the electromagnetic design of a liquid-cooled direct-drive permanent-magnet synchronous generator (LC DD-PMSG) for a directdrive wind turbine application. The analytical calculation of the magnetic field distribution is carried out with the ambition of fast and accurate predicting of the main dimensions of the machine and especially the thickness of the permanent magnets; the generator electromagnetic parameters as well as the design optimization. The focus is on the generator design with a fractional slot non-overlapping winding placed into open stator slots. This is an a priori selection to guarantee easy manufacturing of the LC winding. A thermal analysis of the LC DD-PMSG based on a lumped parameter thermal model takes place with the ambition of evaluating the generator thermal performance. The thermal model was adapted to take into account the uneven copper loss distribution resulting from the skin effect as well as the effect of temperature on the copper winding resistance and the thermophysical properties of the coolant. The developed lumpedparameter thermal model and the analytical calculation of the magnetic field distribution can both be integrated with the presented algorithm to optimize an LC DD-PMSG design. Based on an instrumented small prototype with liquid-cooled tooth-coils, the following targets have been achieved: experimental determination of the performance of the direct liquid cooling of the stator winding and validating the temperatures predicted by an analytical thermal model; proving the feasibility of manufacturing the liquid-cooled tooth-coil winding; moreover, demonstration of the objectives of the project to potential customers.

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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

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Demand for increased energy efficiency has put an immense need for novel energy efficient systems. Electrical machines are considered as a much matured technology. Further improvement in this technology needs of finding new material to incorporate in electrical machines. Progress of carbon nanotubes research over the latest decade can open a new horizon in this aspect. Commonly known as ‘magic material’, carbon nanotubes (CNTs) have promising material properties that can change considerably the course of electrical machine design. It is believed that winding material based on carbon nanotubes create the biggest hope for a giant leap of modern technology and energy efficient systems. Though carbon nanotubes (CNTs) have shown amazing properties theoretically and practically during the latest 20 years, to the best knowledge of the author, no research has been carried out to find the future possibilities of utilizing carbon nanotubes as conductors in rotating electrical machines. In this thesis, the possibilities of utilizing carbon nanotubes in electrical machines have been studied. The design changes of electrical machine upon using carbon nanotubes instead of copper have been discussed vividly. A roadmap for this carbon nanotube winding machine has been discussed from synthesis, manufacturing and operational points of view.

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Prior customer orientation research has concentrated mainly on studying the economical potential of customer orientation to companies. Service quality research instead has concentrated on emphasizing the evaluation of service quality from the customer’s perspective. This means that the service providers lack important information regarding customer orientation and service quality they would need for managerial purposes such as selecting and training employees. Therefore, there is an emerging need to study how customer orientation and service quality relate to company processes, policies and employees, and this study answers to those calls. The objective of this study was to examine what is the role of sales personnel’s’ customer orientation in quality of service delivery and what features support the development of customer orientation among sales personnel. Also the components customer orientation were studied extensively in order to understand how they relate to service quality. The empiric part of the study was conducted as a qualitative research by interviewing seven sales people from operative, tactical and strategic levels of the case corporation in order to get a broader view for customer orientation. The findings propose that both organizational factors and individual factors are affecting customer orientation construct inseparably. Organizational factors are bundled in this study under standards, support and systems, whereas individual factors are formed of employees’ personal attributes, motivation and self-perceived decision making authority. The findings suggest that in the service delivery process at an operative level, customer orientation appears largely in the employees’ individualistic characteristics. Their social and technical skills and motivation to serve customers are the most identifiable factors for customer orientation and consequently, quality service. However, organizational standards, support and systems are strongly dictating the frames the operative sales people operate in, having an influence on how the employees are experiencing their decision making authority and in the end, customer orientation. When looking at the service delivery process at tactical and strategic levels, customer orientation is affecting mainly in the organizational constructs through setting standards, support and systems. However, tactical and strategic level employees influence the operative level through individual customer orientation components as well. The findings indicate that their emotion and personal interaction skills are affecting the overall service delivery process mainly through supervisor support and motivation of the operative level employees. Based on this study it can be argued that an organization can operate as a facilitator and create certain frames for customer oriented sales behavior through standards, support and systems. However, as the impact of individual customer orientation factors on sales people’s service quality seems decisive, from an organizational perspective it puts pressures on the recruitment.

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Hiilinanojohteet ovat sähkönjohteita, joiden valmistuksessa on käytetty hiilinanoputkia, eli yhden atomikerroksen paksuisesta hiiliatomiverkosta koostuvia rakenteita. Hiilinanoputket ovat viime vuosina keränneet suurta mielenkiintoa erinomaisten fysikaalisten ominaisuuksiensa ansiosta. Tämän työn tavoitteena on selvittää, voitaisiinko hiilinanojohteiden sähkönjohtavuus saada riittävälle tasolle, jotta niillä saatettaisiin korvata nykyisiä kuparista valmistettuja johteita. Vaikka kuparilla on erinomainen johtavuus, sen käytöllä on omat heikkoutensa, kuten korkea hinta, virran ahtautuminen, suuri tiheys ja heikko mekaaninen kestävyys. Hiilinanojohteet voisivat olla yksi osa-alue kehitettäessä uusia energiatehokkaita ja ympäristöystävällisiä laitteita nyky-yhteiskunnan tarpeisiin. Työn tulosten perusteella voidaan todeta, että nykyisten hiilinanojohteiden sähkönjohtavuus on yhä liian pieni laajamittaiseen käyttöön. Johtavuus on kuitenkin lisääntynyt jatkuvasti viime vuosina. Kehitystyön avulla hiilimateriaalin potentiaalia saadaan hyödynnettyä koko ajan enemmän, ja ajan myötä hiilijohteista voi tulla varteenotettava kilpailija perinteisille johdemateriaaleille. Hiilinanojohteet tulevat luultavasti aluksi yleistymään käyttökohteissa, joissa niiden muut ominaisuudet täydentävät hyvin sähkönjohtavuutta.

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Wind is one of the most compelling forms of indirect solar energy. Available now, the conversion of wind power into electricity is and will continue to be an important element of energy self-sufficiency planning. This paper is one in a series intended to report on the development of a new type of generator for wind energy; a compact, high-power, direct-drive permanent magnet synchronous generator (DD-PMSG) that uses direct liquid cooling (LC) of the stator windings to manage Joule heating losses. The main param-eters of the subject LC DD-PMSG are 8 MW, 3.3 kV, and 11 Hz. The stator winding is cooled directly by deionized water, which flows through the continuous hollow conductor of each stator tooth-coil winding. The design of the machine is to a large degree subordinate to the use of these solid-copper tooth-coils. Both steady-state and timedependent temperature distributions for LC DD-PMSG were examined with calculations based on a lumpedparameter thermal model, which makes it possible to account for uneven heat loss distribution in the stator conductors and the conductor cooling system. Transient calculations reveal the copper winding temperature distribution for an example duty cycle during variable-speed wind turbine operation. The cooling performance of the liquid cooled tooth-coil design was predicted via finite element analysis. An instrumented cooling loop featuring a pair of LC tooth-coils embedded in a lamination stack was built and laboratory tested to verify the analytical model. Predicted and measured results were in agreement, confirming the predicted satisfactory operation of the LC DD-PMSG cooling technology approach as a whole.

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In this thesis, bacteriorhodopsin (BR) photosensor’s optical and electrical properties were studied. The BR sensor consisted of a dry film with BR in polyvinyl alcohol and covered with transparent conductors. In the experiments the BR photocycle was started with two lasers. The characteristics of the BR sensor were measured in two ways. The first approach was theoretical and it required knowing the laser parameters. The second way required assembling a measurement setup for the optical response measurements. However, no measurable results were obtained due to low laser power. The photoelectric response was measured in the experiments with two laser systems and the amplifier was tested. In the experiment with a Cavitar laser, the photoelectric response was obtained. In the experiment with FemtoFiber Pro laser, the photoelectric response was not measured. The expected amplitude of the response was obtained. The experimental data was analyzed and possible solutions for reducing the interference were given.

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In 1948, The St. Catharines Civic Orchestra was founded by Jan Wolanek who was also the first conductor. Initially, this was a community orchestra and in 1963 its governing body assumed the name St. Catharines Symphony Association. In 1978 the name was again changed to The Niagara Symphony Association to reflect regional responsibilities. Wally Laughton was named Assistant Conductor in 1952/53. R.C. Clarke took over the orchestra for an interim period after Wolanek left in 1957. In 1958 Leonard Pearlman became the Music Director. It was under his direction that the Niagara Symphony Chorus came into existence in 1963. Milton Barnes succeeded Pearlman in 1964 and he was responsible for directing the symphony’s first opera production. He also made a concerted effort to attract younger people to symphonic music. In 1972 Leonard Atherton became the Music Director. He started the Cantata Choir and the Madrigal Singers. It was under his tenure that the orchestra became professional. When Atherton left in 1980, there were three seasons of guest conductors, the most notable of these conductors was Uri Mayer. In 1981 James Vincent Fusco was appointed as composer in residence and in 1983 Ermanno Florio became the Music Director. He retained this position until 1995 when Michael Reason took over. Daniel Swift was appointed as Music Director and Conductor in 1999 and the Niagara Symphony Orchestra became the orchestr in residence at Brock University. Laura Thomas was appointed as Associate Conductor 1n 2004. Daniel Swift’s resignation in 2008 began a search for a new Music Director. Bradley Thachuck was appointed as Music Director Designate and Principal Conductor in 2010. The orchestra is a fully professional, charitable institution with 52 members.The orchestra has also been led by Victor Feldbrill and Howard Cable. A junior symphony was first formed under Leonard Pearlman in 1960/61, but it wasn’t until 1965 that The St. Catharines Youth Orchestra was founded. The orchestra has consistently been an award winner in music festivals. The musicians range in age from 12 to 18 years. The highlight of the 1973-74 season was the orchestra’s participation in the first Canadian Festival of Youth Orchestras at The Banff School of Fine Arts. The St. Catharines Youth Orchestra has evolved from the St. Catharines School String and Brass Ensembles to a full scale symphony under the direction of conductor Paul van Dongen. In 1974 the Symphony House music program came into existence. It was 1976 when Richard Grymonpre was hired as the principal violinist of the St. Catharines Symphony Orchestra and conductor of the St. Catharines Youth Orchestra. Tak Ng Lai took over the position as conductor in 1978. Laura Thomas is currently the Music Director of The Niagara Youth Orchestra. Source: Niagara Symphony, Orchestra in Residence, Brock University website and notes from Niagara Symphony files

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Two classes of compounds have been prepared and characterized as building blocks for chiral magnets and ferromagnetic conductors. In the fIrst project, the organic framework of a pentadentate, (N302) macro cycle has been synthetically modifIed to introduce phenyl substituents into its organic framework and the synthesis of four new [Fe(In(N302)(CN)2] complexes (I) - (IV) is presented. [Molecular diagram availble in pdf] This work represents the fIrst structural and magnetic studies of a family of spin crossover macrocycles that comprise of both structural and stereo-isomers. Magnetic susceptibility and Mossbauer data for the R,R-complex (I) is consistent with both a thermal and a light induced spin crossover transition. The X-ray data supports a change in geometry accompanying the thermal spin transition, from a high spin (HS) 7 -coordinate complex at room temperature to a low spin (LS) 5-coordinate complex at 100 K. The crystal structure ofthe racemic complex (III) reveals a HS, 7-coordinate complex at 200 K that undergoes no signifIcant structural changes on cooling. In contrast, the magnetic - susceptibility and Mossbauer data collected on a powder sample of the racemic complex are consistent with a LS complex. Finally, the meso complex (IV) was prepared and its structure and magnetic properties are consistent with a 5-coordinate LS complex that remains low spin, but undergoes conformational changes on cooling in solution. The chiral [Fe(H)(N302)(CN)2] macro cycle (I), together with its Mn(H) and Fe(H) derivatives have also been exploited as building blocks for the self-assembly of chiral magnets. In the second project, a synthetic route for the preparation of tetrathiafulvalene (TTF) donors covalently attached to a diisopropyl verdazyl radical via a cross conjugated pyridyl linker IS presented. Following this strategy, four new TTF-py- (diisopropyl)verdazyl radicals have been prepared and characterized (V) - (VIII) . [Molecular diagram available in pdf] The first (2:1) charge transfer complex ofa TTF-py-(diisopropyl)verdazyl radical donor and a TCNQ acceptor has been prepared and structurally characterized. The crystal packing shows that the donor and acceptor molecules are organized in a mixed stacking arrangement consistent with its insulating behaviour. EPR and magnetic susceptibility data support intramolecular ferromagnetic interactions between the TTF and the verdazyl radicals and antiferromagnetic interactions between TTF donors within a stack. In an attempt to increase the intramolecular exchange interaction between the two radicals, a TTF-x-(diisopropyl)verdazyl radical (IX) was prepared, where the two radicals are connected ia a conjugated divinylene linker. The neutral radical donors stack in a more favourable head-to-head arrangement but the bulky isopropyl groups prevent the donor radicals from stacking close enough together to facilitate good orbital overlap. [Molecular diagram available in pdf].

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The increasing interest in the interaction of light with electricity and electronically active materials made the materials and techniques for producing semitransparent electrically conducting films particularly attractive. Transparent conductors have found major applications in a number of electronic and optoelectronic devices including resistors, transparent heating elements, antistatic and electromagnetic shield coatings, transparent electrode for solar cells, antireflection coatings, heat reflecting mirrors in glass windows and many other. Tin doped indium oxide (indium tin oxide or ITO) is one of the most commonly used transparent conducting oxides. At present and likely well into the future this material offers best available performance in terms of conductivity and transmittivity combined with excellent environmental stability, reproducibility and good surface morphology. Although partial transparency, with a reduction in conductivity, can be obtained for very thin metallic films, high transparency and simultaneously high conductivity cannot be attained in intrinsic stoichiometric materials. The only way this can be achieved is by creating electron degeneracy in a wide bandgap (Eg > 3eV or more for visible radiation) material by controllably introducing non-stoichiometry and/or appropriate dopants. These conditions can be conveniently met for ITO as well as a number of other materials like Zinc oxide, Cadmium oxide etc. ITO shows interesting and technologically important combination of properties viz high luminous transmittance, high IR reflectance, good electrical conductivity, excellent substrate adherence and chemical inertness. ITO is a key part of solar cells, window coatings, energy efficient buildings, and flat panel displays. In solar cells, ITO can be the transparent, conducting top layer that lets light into the cell to shine the junction and lets electricity flow out. Improving the ITO layer can help improve the solar cell efficiency. A transparent ii conducting oxide is a material with high transparency in a derived part of the spectrum and high electrical conductivity. Beyond these key properties of transparent conducting oxides (TCOs), ITO has a number of other key characteristics. The structure of ITO can be amorphous, crystalline, or mixed, depending on the deposition temperature and atmosphere. The electro-optical properties are a function of the crystallinity of the material. In general, ITO deposited at room temperature is amorphous, and ITO deposited at higher temperatures is crystalline. Depositing at high temperatures is more expensive than at room temperature, and this method may not be compatible with the underlying devices. The main objective of this thesis work is to optimise the growth conditions of Indium tin oxide thin films at low processing temperatures. The films are prepared by radio frequency magnetron sputtering under various deposition conditions. The films are also deposited on to flexible substrates by employing bias sputtering technique. The films thus grown were characterised using different tools. A powder x-ray diffractometer was used to analyse the crystalline nature of the films. The energy dispersive x-ray analysis (EDX) and scanning electron microscopy (SEM) were used for evaluating the composition and morphology of the films. Optical properties were investigated using the UVVIS- NIR spectrophotometer by recording the transmission/absorption spectra. The electrical properties were studied using vander Pauw four probe technique. The plasma generated during the sputtering of the ITO target was analysed using Langmuir probe and optical emission spectral studies.

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Materials exhibiting transparency and electrical conductivity simultaneously, transparent conductors, Transparent conducting oxides (TCOs), which have high transparency through the visible spectrum and high electrical conductivity are already being used in numerous applications. Low-emission windows that allow visible light through while reflecting the infrared, this keeps the heat out in summer, or the heat in, in winter. A thin conducting layer on or in between the glass panes achieves this. Low-emission windows use mostly F-doped SnO2. Most of these TCO’s are n type semiconductors and are utilized in a variety of commercial applications, such as flat-panel displays, photovoltaic devices, and electrochromic windows, in which they serve as transparent electrodes. Novel functions may be integrated into the materials since oxides have a variety of elements and crystal structures, providing great potential for realizing a diverse range of active functions. However, the application of TCOs has been restricted to transparent electrodes, notwithstanding the fact that TCOs are n-type semiconductors. The primary reason is the lack of p-type TCOs, because many of the active functions in semiconductors originate from the nature of the pn-junction. In 1997, H. Kawazoe et al.[2] reported CuAlO2 thin films as a first p-type TCO along with a chemical design concept for the exploration of other p-type TCOs.