1,369 research outputs found

    On the Chinese Exchange Rate Regime: an Attempt to Flexibility during 2015

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    This study will demonstrate, through an econometric and asset allocation approach, if and how the Chinese exchange rate regime was changing during 2015. Particularly, China to improve its exchange rate formation system implemented, during July and August 2015, three depreciation as a step toward a market-oriented exchange rate. This situation, along with the new right of the RMB to be an international currency in SDR should generate a loss of weight about the USD in the Chinese basket peg. For this reason, moving from Frankel-Wei’s basic econometric model - but with some appropriate changes - our objective is to verify if the Chinese monetary policy about the exchange rate has affected the inner balance of the Chinese basket-peg leading it towards a flexible exchange rate regime

    Template electrosynthesis of La(OH)3 and Nd(OH)3 nanowires using porous anodic alumina membranes

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    High quality arrays of Ln(OH)3 (Ln = La, Nd) nanowires have been successfully fabricated for the first time by an electrochemical process using anodic alumina membrane templates. A physico-chemical characterisation of electrodeposited hydroxides has been carried out by different techniques (XRD, SEM and EDX). The results show that the synthesized nanostructures are crystalline, dense, continuous, well aligned, and with high aspect ratio, suggesting further development of possible applications in the lanthanide family species

    Structural Analysis and Photocurrent Spectroscopy of CCCs on 99.99% Aluminum

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    A characterization of chromate conversion coatings (CCCs) formed in the presence and in the absence of accelerator (ferro-ferricyanide redox couple) has been performed by various techniques (transmission electron microscopy, TEM, glow discharge optical emission spectrometry, GDOES, X-ray absorption near-end structure, XANES, and photon correlation spectroscopy). The results of a detailed investigation on morphological, compositional, and solid-state properties of freshly converted aluminum samples at different immersion times (30 s-90 min) are reported. The TEM and GDOES data suggest the presence of iron-cyanide species only in the external layer of CCC of nearly constant thickness. The XANES data suggest the presence of both Cr(VI) and Cr(III) species with a ratio Cr(VI)/Cr(III) close to 1:2. This ratio remains constant with the conversion time and seems slightly affected by the composition of conversion solution. The photoelectrochemical study suggests an insulating or slightly p-type behavior for CCC layers. A bandgap value of about 2.55 eV has been estimated, regardless of the conversion solution, although some differences in the photocurrent spectra have been observed for coatings formed in the presence or absence of accelerator. The location of electronic energy levels of the Al/CCC/electrolyte interface has been derived which could account for the different kinetics of coating formation in the presence of accelerator

    Physicochemical Characterization of Passive Films and Corrosion Layers by Differential Admittance and Photocurrent Spectroscopy

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    Two different electrochemical techniques, differential admittance and photocurrent spectroscopy, for the characterization of electronic and solid state properties of passive films and corrosion layers are described and critically evaluated. In order to get information on the electronic properties of passive film and corrosion layers as well as the necessary information to locate the characteristic energy levels of the passive film/electrolyte junction like: flat band potential (Ufb), conduction band edge (EC) or valence band edge (EV), a wide use of Mott-Schottky plots is usually reported in corrosion science and passivity studies. It has been shown, in several papers, that the use of simple M-S theory to get information on the electronic properties and energy levels location at the film/electrolyte interface can be seriously misleading and/or conflicting with the physical basis underlying the M-S theory. A critical appraisal of this approach to the study of very thin and thick anodic passive film grown on base-metals (Cr, Ni, Fe, SS etc..) or on valve metals (Ta, Nb, W etc..) is reported in this work, together with possible alternative approach to overcome some of the mentioned inconsistencies. At this aim the theory of amorphous semiconductor Schottky barrier, introduced several years ago in the study of passive film/electrolyte junction, is reviewed by taking into account some of the more recent results obtained by the present authors. Future developments of the theory appears necessary to get more exact quantitative information on the electronic properties of passive films, specially in the case of very thin film like those formed on base metals and their alloys. The second technique described in this chapter, devoted to the physico-chemical characterization of passive film and corrosion layers, is a more recent technique based on the analysis of the photo-electrochemical answer of passive film/electrolyte junction under illumination with photons having suitable energy. Such a technique usually referred to as Photocurrent Spectroscopy (PCS) has been developed on the basis of the large research effort carried out by several groups in the 1970’s and aimed to investigate the possible conversion of solar energy by means of electrochemical cells. In this work the fundamentals of semiconductor/electrolyte junctions under illumination will be highlighted both for crystalline and amorphous materials. The role of amorphous nature and film thickness on the photo-electrochemical answer of passive film/solution interface is reviewed as well the use of PCS for quantitative analysis of the film composition based on a semi-empirical correlation between optical band gap and difference of electronegativity of film constituents previously suggested by the present authors. In this frame the results of PCS studies on valve metal oxides and valve metal mixed oxides will be discussed in order to show the validity of the proposed method. The results of PCS studies aimed to get information on passive film composition and carried out by different authors on base metals (Fe, Cr, Ni) and their alloys, including stainless steel, will be also compared with compositional analysis carried out by well-established surface analysis techniques

    MANAJEMEN PEMBINAAN PERPUSTAKAAN KELURAHAN DI KOTA BANDUNG

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    Dinas Perpustakaan dan Kearsipan (Dispusip) Kota Bandung merupakan suatu bentuk dari perpustakaan umum yang memiliki fungsi membina perpustakaan. Pemberdayaan perpustakaan kelurahan di Kota Bandung saat ini belum terealisasi sesuai dengan jumlah kelurahan yang terdapat di kota Bandung sebanyak 151 kelurahan. Perpustakaan kelurahan dapat menjalankan fungsinya dengan baik sesuai dengan fungsi perpustakaan dengan penerapan fungsi manajemen perpustakaan. Masalah yang menjadi kajian pada penelitian ini bagaimana implementasi manajemen pembinaan perpustakaan kelurahan di Kota Bandung oleh Dispusip Kota Bandung. Tujuan penelitian ini yaitu untuk mendeskripsikan mengenai perencanaan, pengorganisasian, penggerakan dan pengawasan pembinaan perpustakaan kelurahan oleh Dispusip Kota Bandung. Metode yang digunakan pada penelitian ini adalah metode kualitatif dengan pendekatan studi kasus. Partisipan dalam penelitian ini terdiri atas tiga informan yang bertindak sebagai pustakawan dan key informan sebagai Kepala Bidang Pengembangan Perpustakaan dan Kearsipan menggunakan teknik purposive sampling. Instrumen penelitian yang digunakan adalah wawancara, observasi dan studi dokumentasi. Teknik analisis data yang digunakan adalah data reduction, data display, dan conclusion drawing (verification). Berdasarkan hasil penelitian yaitu sebuah konstuksi model manajemen pembinaan perpustakaan kelurahan yang menunjukkan bahwa kegiatan pembinaan perpustakaan kelurahan oleh Dispusip Kota Bandung relevan dengan fungsi manajemen. Fungsi perencanaan, pengorganisasian, penggerakan kegiatan manajemen pembinaan perpustakaan kelurahan di Kota Bandung terealisasi cukup baik. Namun pada fungsi pengawasan belum berjalan secara optimal, hal ini dikarenakan oleh keterbatasan sumber daya manusia yang dimiliki oleh Dispusip Kota Bandung. Program pembinaan ini diharapkan dapat mewujudkan penyelenggaraan perpustakaan kelurahan dan dapat memberikan kontribusi terhadap perbaikan/ penyempurnaan manajemen pembinaan perpustakaan oleh Dispusip Kota Bandung. ;--- Dinas Perpustakaan dan Kearsipan (Dispusip) Kota Bandung is a form of public library, which function is to develop urban village libraries. Currently, the empowerment of urban village libraries in 151 village in Bandung City is not realized yet. Urban village libraries can perform its functions properly in accordance with the implementation of library management functions. The problem of this study is how Dispusip Kota Bandung manages the implementation of urban village libraries coaching in Bandung City. The purpose of this study is to describe the planning, organizing, actuating, and controlling of urban village libraries coaching by Dispusip Kota Bandung. The research method used in this study is qualitative method with a case study approach. The subjects of this study consist of three informants who act as a librarian and a key informant as a Head of Library and Archive Development by using purposive sampling technique. The research instruments used in this study are interviews, observations, and documentation studies. This study uses data analysis technique of data reduction, data display, and conclusion drawing (verification). Based on the study of a model construction of urban village libraries coaching, the result is that the coaching activities of urban village libraries done by Dispusip Kota Bandung is relevant to the management functions. The functions of planning, organizing, and actuating of village libraries coaching activities in Bandung City are realized quite well. However, the function of controlling has not run optimally. This is due to the limitations of human resources owned by Dispusip Kota Bandung. This coaching program is expected to be able to realize the enforcement of urban village libraries and to give contribution to the improvement of library coaching management done by Dispusip Kota Bandung

    Study on ZrB2-based ceramics reinforced with SiC fibers or whiskers machined by micro-electrical discharge machining

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    The effects of different reinforcement shapes on stability and repeatability of micro electrical discharge machining were experimentally investigated for ultra-high-temperature ceramics based on zirconium diboride (ZrB2) doped by SiC. Two reinforcement shapes, namely SiC short fibers and SiC whiskers were selected in accordance with their potential effects on mechanical properties and oxidation performance. Specific sets of process parameters were defined minimizing the short circuits in order to identify the best combination for different pulse types. The obtained results were then correlated with the energy per single discharge and the discharges occurred for all the combinations of material and pulse type. The pulse characterization was performed by recording pulses data by means of an oscilloscope, while the surface characteristics were defined by a 3D reconstruction. The results indicated how reinforcement shapes affect the energy efficiency of the process and change the surface aspect
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