Principles of Language Learning and Teaching

The End of History and the Last Man

In this chapter we will be concentrating on one of the key processes in the ‘cultural circuit’ (see Du Gay et al., 1997, and the Introduction to this volume) – the practices of representation. The aim of this chapter is to introduce you to this topic, and to explain what it is about and why we give it such importance in cultural studies. The concept of representation has come to occupy a new and important place in the study of culture. Representation connects meaning and language to culture. But what exactly do people mean by it? What does representation have to do with culture and meaning? One common-sense usage of the term is as follows: ‘Representation means using language to say something meaningful about, or to represent, the world meaningfully, to other people.’ You may well ask, ‘Is that all?’ Well, yes and no. Representation is an essential part of the process by which meaning is produced and exchanged between members of a culture. It does involve the use of language, of signs and images which stand for or represent things. But this is a far from simple or straightforward process, as you will soon discover. How does the concept of representation connect meaning and language to culture? In order to explore this connection further, we will look at a number of different theories about how language is used to represent the world. Here we will be drawing a distinction between three different accounts or theories: the reflective, the intentional and the constructionist approaches to representation. Does language simply reflect a meaning which already exists out there in the world of objects, people and events (reflective)? Does language express only what the speaker or writer or painter wants to say, his or her personally intended meaning (intentional)? Or is meaning constructed in and through language (constructionist)? You will learn more in a moment about these three approaches. Most of the chapter will be spent exploring the constructionist approach, because it is this perspective which has had the most significant impact on cultural studies in recent years. This CHAPTER ONE

From Work to Representation

Understanding second language acquisition

Dye-sensitized solar cells (DSSCs) belong to the group of thin-film solar cells which have been under extensive research for more than two decades due to their low cost, simple preparation methodology, low toxicity and ease of production. Still, there is lot of scope for the replacement of current DSSC materials due to their high cost, less abundance, and long-term stability. The efficiency of existing DSSCs reaches up to 12%, using Ru(II) dyes by optimizing material and structural properties which is still less than the efficiency offered by first- and second-generation solar cells, i.e., other thin-film solar cells and Si-based solar cells which offer ~ 20–30% efficiency. This article provides an in-depth review on DSSC construction, operating principle, key problems (low efficiency, low scalability, and low stability), prospective efficient materials, and finally a brief insight to commercialization.

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Dye-Sensitized Solar Cells: Fundamentals and Current Status

In this study, dye-sensitized solar cells (DSSCs) were fabricated using double-layer photoanodes consisting of TiO 2 nanoparticles (NPs) and Zn-doped TiO 2 hollow fibers (HFs). The TiO 2 HFs were prepared by co-axial electrospinning and used as the light-scattering layer in the DSSC. The thickness variations of the TiO 2 NP and Zn-doped TiO 2 HF photoanode layers affect the performance of the DSSC, especially the short-circuit photocurrent density. The thickness of the TiO 2 NP layer significantly affected the absorbance of photons and N719 dye molecules in the double-layer photoanode, while that of the Zn-doped TiO 2 HF layer affected the scattering of light, as indicated by the low light transmittance in the photoanode. Conventional DSSCs consist of single-layer photoanodes, and exhibit relatively low efficiency, i.e., 1.293% and 0.89% for TiO 2 NP and Zn-doped TiO 2 HF, respectively. However, herein, the highest efficiency of the DSSC (3.122%) was achieved with a 15 μm NP-5 μm HF photoanode, for which the short-circuit photocurrent density, open-circuit photovoltage, and fill factor were 15.81 mA/cm 2 , 0.566 V, and 34.91%, respectively.

Improved Performance of Dye-Sensitized Solar Cells with TiO 2 Nanoparticles/Zn-Doped TiO 2 Hollow Fiber Photoanodes

Stability and efficiency of dye-sensitized solar cells based on papaya-leaf dye.

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Exploring the Implementation of Local Wisdom-Based Character Education among Indonesian Higher Education Students.

Dye-sensitized solar cells (DSSCs) based on natural sensitizers have become a topic of significant research because of their urgency and importance in the energy conversion field and the following advantages: ease of fabrication, low-cost solar cell, and usage of nontoxic materials. In this study, the chlorophyll extracted from papaya leaves was used as a natural sensitizer. Dye molecules were adsorbed by TiO2 nanoparticle surfaces when submerged in the dye solution for 24 h. The concentration of the dye solution influences both the amount of dye loading and the DSSC performance. The amount of adsorbed dye molecules by TiO2 nanoparticle was calculated using a desorption method. As the concentration of dye solution was increased, the dye loading capacity and power conversion efficiency increased. Above 90 mM dye solution concentration, however, the DSSC efficiency decreased because dye precipitated on the TiO2 nanostructure. These characteristics of DSSCs were analyzed under the irradiation of 100 mW/cm2. The best performance of DSSCs was obtained at 90 mM dye solution, with the values of , ,  FF, and efficiency of DSSCs being 0.561 V, 0.402 mA/cm2, 41.65%, and 0.094%, respectively.

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Performance Enhancement of Dye-Sensitized Solar Cells Using a Natural Sensitizer

The objectives of this  study were :  ( 1)  to determine  the process of  the  interactive media development for the  course of   Technical Measur e ment,  and ( 2)  to analyse  the e f fectiveness of  the  media. This study is  categorised into  research and development.  The data collection techniques used  questionaires and tests. The results  show :  ( 1) the process of  the  interactive  media development consisted of  needs analysis, product development, individual  test , small group s  test and  final  product implementation.  ( 2) The  developed  product  is proved to be an effective instructional  media  to improve the students’ achievement in  the  course of  Technical Measur e ment.  There is a positive and significant difference between the students treated with the developed interactive media and the students treated with the conventional media .  It was supported by the mean scores of the experimental and control groups were 78.83 and 69.78 respectively. Penelitian ini bertujuan untuk mengetahui: (1) proses pengembangan media interaktif untuk  pembelajaran pengukuran teknik; dan (2) efektivitas pengembangan media interaktif untuk  pembelajaran pengukuran teknik. Penelitian ini merupakan research and development . Pengumpulan data dilakukan menggunakan angket dan tes. Hasil penelitian antara lain: (1) proses pembuatan media pembelajaran dilakukan melalui tiga tahap yaitu: analisis kebutuhan, pengembangan produk,  uji coba satu-satu, uji coba kelompok kecil dan implementasi produk akhir; dan (2) produk multimedia ini dapat digunakan sebagai salah satu media untuk meningkatkan pemahaman materi pengukuran teknik. Terdapat perbedaan hasil belajar antara siswa yang menggunakan media interaktif dan siswa yang menggunakan media konvensional. Media interaktif  lebih efektif daripada media konvensional, dapat dilihat dari  rerata kelas eksperimen sebesar 78,83 yang lebih besar dari rerata kelas kontrol sebesar 69,78.

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Suyitno Suyitno

Papers

Improved Performance of Dye-Sensitized Solar Cells with TiO 2 Nanoparticles/Zn-Doped TiO 2 Hollow Fiber Photoanodes

Stability and efficiency of dye-sensitized solar cells based on papaya-leaf dye.

Exploring the Implementation of Local Wisdom-Based Character Education among Indonesian Higher Education Students.

Performance Enhancement of Dye-Sensitized Solar Cells Using a Natural Sensitizer

Pengembangan Multimedia Interaktif Pengukuran Teknik untuk Meningkatkan Hasil Belajar Siswa SMK