CO2 Kuznets Curve Revisited: From Cross-Sections to Panel Data Models

The Environmental Kuznets Curve (EKC) predicts that environmental degradation intensifies when per capita income increases and subsequently subsides after a certain income level is reached, resulting in an inverted U-shaped relationship. There is abundant literature on the topic that corroborates the existence of a positive income elasticity for environmental quality. However, results are controversial. We take the case of CO2, by comparing the results of the cross-sectional estimates with those derived from a panel approach. To this end, we use data from 182 countries during the period 1992-2011. We found that the EKC hypothesis is acceptable under both approaches, although the estimated turning points in cross-sections seem unreliable. Our application underlines the importance of adequately address central problems such as heterogeneity, structural breaks and spatial interaction. La curva de Kuznets (EKC) predice que la degradación medioambiental se intensifica inicialmente al aumentar la renta per cápita, para disminuir a continuación tras haber alcanzado cierto nivel de renta o turning point. Esta estructura se traduce en una relación en forma de U invertida entre ambas variables. Existe abundante literatura sobre el tema que corrobora la existencia de una elasticidad neta positiva para la calidad medioambiental. Sin embargo, los resultados son controvertidos. Analizamos el caso de CO2 comparando los resultados de las estimaciones transversales, con las derivadas de un enfoque panel. Para ello utilizamos datos de 182 países durante el periodo 1992-2011. Comprobamos que la hipótesis EKC resulta aceptable bajo ambos enfoques, aunque los turning point estimados en los cortes transversales son poco creíbles. Nuestra aplicación subraya la importancia de tratar adecuadamente problemas centrales como la heterogeneidad, las rupturas estructurales y la interacción espacial

Studi Pengembangan Model Baru Bahan Belajar Universitas Terbuka

Salah satu tantangan yang dihadapi institusi pendidikan jarak jauh adalah memaksimumkan efektivitas bahan belajar yang digunakan. Hasil studi tentang bahan belajar modul yang pernah dilakukan menunjukkan adanya tuntutan akan peningkatkan kualitas bahan belajar, baik dari segi desain instruksionalnya, maupun dari segi pemanfaatan teknologinya. Universitas Terbuka sebagai institusi pendidikan jarak jauh perlu menyusun dan menciptakan suatu pola baru cara pengorganisasian bahan belajar yang sesuai dengan kebutuhan sekarang ataupun masa datang. Karena itu diadakan studi yang bertujuan untuk mengembangkan model baru bahan belajar UT sehingga diperoleh pola pengorganisasian bahan belajar yang fleksibel, berkualitas tinggi, dan memanfaatkan teknologi yang maksimal. Studi pengembangan ini dilaksanakan melalui 3 tahap penelitian yang masing-masing memerlukan waktu 1 tahun. Studi Tahap I mencakup 3 jenis kegiatan yaitu Studi Dokumentasi, Lokakarya Perumusan Konsep dan Seminar tentang Konsep Dasar pengembangan Modul yang Baru. Dalam studi dokumentasi telah dikumpulkan berbagai bahan belajar dari Negara yang mengembangkan program belajar jarak jauh, yaitu Canada, Inggris, Australia, Malaysia, India, Jepang (tidak dapat dianalisis, karena disampaikan dalam bahas Kanji/Jepang) dan Indonesia. Bahan belajar terdiri dari mata kuliah-mata kuliah di bidang IPA dan IPS. Dalam pengkajiannya, bahan belajar diseleksi dan diidentifikasi untuk melihat komponen yang terdapat dalam perangkat tersebut, dan peranan dari media elektronik yang digunakan misalnya audio kaset atau video. Studi ini antara lain menemukan bahwa isi paket matakuliah non Asia minimal terdiri dari katalog matakuliah, BMP, dan buku kerja, sedangkan paket matakuliah dari negara-negara di Asia umumnya hanya terdiri dari BMP dan media penunjang saja. Adanya penjadualan untuk mempela jari modul sangat membantu mahasiswa, dan adanya katalog memungkinkan mahasiswa mengenali karakteristik setiap matakuliah, termasuk system penilaiannya. Model paket matakuliah yang paling lengkap adalah paket dari Athabasca University Canada, sedangkan model yang unik (kumpulan artikel dan study guide) berasal dari Monas Distance Education (Australia). Peranan tutor dalam proses belajar mahasiswa cukup besar dan umpan balik yang diberikan umumnya terprogram dengan baik. Pada umumnya pemanfaatan media elektronik dirancang bersamaan dengan media cetaknya dan bersifat integrated. Media elektronik memuat penjelasan tentang hal-hal pokok dan penting dalam•perkuliahan, dengan mempertimbangkan faktor kesendirian mahasiswa dan faktor kejenuhan mereka. Adanya rekomendasi dari studi ini adalah studi dokumentasi sebaiknya dilengkapi dengan pengkajian berdasarkan aspek psikologis, paedagogis, substantif, dan ekonomis dari bahan yang dikaji. Bahan belajar sebaiknya dilengkapi dengan buku pedoma mahasiswa untuk setiap matakuliah, yang dituangkan dalam bentuk cetak ataupun kaset audio dan video. Pengembangan Bahan belajar non cetak hendaknya memuat strategi-strategi baru. Umpan balik untuk mahasiswa lebih ditingkatkan, misalnya melalui radio. Hasil penelitian setiap tahap akan diinformasikan kepada fakultas agar proses evaluasi berjalan seiring dengan pengembangan modul di fakultas

International differences in employee silence motives: Scale validation, prevalence, and relationships with culture characteristics across 33 Countries

Employee silence, the withholding of work-related ideas, questions, or concerns from someone who could effect change, has been proposed to hamper individual and collective learning as well as the detection of errors and unethical behaviors in many areas of the world. To facilitate cross-cultural research, we validated an instrument measuring four employee silence motives (i.e., silence based on fear, resignation, prosocial, and selfish motives) in 21 languages. Across 33 countries (N = 8,222) representing diverse cultural clusters, the instrument shows good psychometric properties (i.e., internal reliabilities, factor structure, measurement invariance). Results further revealed similarities and differences in the prevalence of silence motives between countries, but did not necessarily support cultural stereotypes. To explore the role of culture for silence, we examined relationships of silence motives with the societal practices cultural dimensions from the GLOBE Program. We found relationships between silence motives and power distance, institutional collectivism, and uncertainty avoidance. Overall, the findings suggest that relationships between silence and cultural dimensions are more complex than commonly assumed. We discuss the explanatory power of nations as (cultural) units of analysis, our social scientific approach, the predictive value of cultural dimensions, and opportunities to extend silence research geographically, methodologically, and conceptuallyinfo:eu-repo/semantics/publishedVersio

Stable Au-Ag alloy nanoparticles encapsulated in single crystal multi-hollow zeolites

SSCI-VIDE+ING+RAT:FRM:ATUInternational audienceHighly dispersed Au, Ag and Au-Ag alloy nanoparticles were homogeneously embedded in a chemically inert matrix made of silicalite-1 multi-hollow single crystals. The particles were fully accessible to small reactant molecules such as CO. The Au nanoparticles were as active as the Ag-Au material for CO oxidation at room temperature. Operando diffuse reflectance FT-IR spectroscopy revealed the presence of both metals at the surface of the particles, silver replacing a large fraction of the Au atoms otherwise located at low coordination sites. This study shows that CO adsorption followed by IR is a useful technique to estimate the surface composition of nanoalloy particles buried in a zeolite matrix

Highly dispersed Au, Ag and Au-Ag alloy nanoparticles encapsulated in single crystal multi-hollow silicalite-1

SSCI-VIDE+ING+RAT:ATU:FRMInternational audienceHighly dispersed Au, Ag and Au-Ag alloy nanoparticles were homogeneously embedded in a chemically inert matrix made of silicalite-1 multi-hollow single crystals. The particles were fully accessible to small reactant molecules such as CO. The Au nanoparticles were as active as the Ag-Au material for CO oxidation at room temperature. Operando diffuse reflectance FT-IR spectroscopy revealed the presence of both metals at the surface of the particles, silver replacing a large fraction of the Au atoms otherwise located at low coordination sites. Thisstudy shows that CO adsorption followed by IR is a useful technique to estimate the surface composition of nanoalloy particles buried in a zeolite matrix

Highly dispersed Au, Ag and Au-Ag alloy nanoparticles encapsulated in single crystal multi-hollow silicalite-1

SSCI-VIDE+ING+RAT:ATU:FRMInternational audienceHighly dispersed Au, Ag and Au-Ag alloy nanoparticles were homogeneously embedded in a chemically inert matrix made of silicalite-1 multi-hollow single crystals. The particles were fully accessible to small reactant molecules such as CO. The Au nanoparticles were as active as the Ag-Au material for CO oxidation at room temperature. Operando diffuse reflectance FT-IR spectroscopy revealed the presence of both metals at the surface of the particles, silver replacing a large fraction of the Au atoms otherwise located at low coordination sites. Thisstudy shows that CO adsorption followed by IR is a useful technique to estimate the surface composition of nanoalloy particles buried in a zeolite matrix

Stable Au-Ag alloy nanoparticles encapsulated in single crystal multi-hollow zeolites

SSCI-VIDE+ING+RAT:FRM:ATUInternational audienceHighly dispersed Au, Ag and Au-Ag alloy nanoparticles were homogeneously embedded in a chemically inert matrix made of silicalite-1 multi-hollow single crystals. The particles were fully accessible to small reactant molecules such as CO. The Au nanoparticles were as active as the Ag-Au material for CO oxidation at room temperature. Operando diffuse reflectance FT-IR spectroscopy revealed the presence of both metals at the surface of the particles, silver replacing a large fraction of the Au atoms otherwise located at low coordination sites. This study shows that CO adsorption followed by IR is a useful technique to estimate the surface composition of nanoalloy particles buried in a zeolite matrix

Contributions and limitations of IR spectroscopy of CO adsorption to the characterization of bimetallic and nanoalloy catalysts

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Stable Au-Ag alloy nanoparticles encapsulated in single crystal multi-hollow zeolites: application to CO removal at low temperature studied by operando IR spectroscopy

MICROSCOPIE+ING+RAT:ATU:LBU:FRMInternational audienceThe preparation of well-defined and stable alloy nanoparticle remains a challenge. We have shown that it was possible to prepare well-defined alloy nanoparticles encapsulated in single crystal hollow zeolite nanoboxes that were stable at 500°C in the presence of steam. The overall metal loading in these single hollow nanoboxes had yet to be kept low if the preparation of small particles was sought. We have recently reported a novel method to prepare well-dispersed nickel nanoparticles at high loading (i.e. 6 wt.%) using multi-hollow single crystal zeolites.The present contribution reports for the first time the preparation of Au and Au-Ag nanoparticles dispersed in multi-hollow silicalite-1 single crystals, derived from the method reported earlier2. Highly dispersed Au and Au-Ag nanoparticles with a diameter around 3 nm were obtained, even after calcination at 550°C.The CO oxidation activity and the species present at the surface of the catalyst were evaluated using a diffuse reflectance FT-IR spectroscopic (DRIFTS) cell described elsewhere. The Au and Au-Ag materials exhibited a maximum of activity, as expected1. Surprisingly, the Au-only sample was as active as the Au-Ag sample at lower temperatures, possibly due to a large fraction of low coordination sites that are able to adsorb and activate CO. This was confirmed by the operando DRIFTS data, which showed a significantly higher band at 2134 cm-1, corresponding to CO adsorbed on step and corner sites4. The proportion of these sites was lower on the Au-Ag sample, but the alloy exhibited partially oxidised Ag sites (bands at 2189 and 2172 cm-1) that could too adsorb CO. The activity of an Ag-only sample was significantly lower over this temperature range, stressing again the synergy existing between Au and Ag for CO oxidation.This work shows that it is possible to prepare highly dispersed and stable Au and Au-Ag nanoparticles in multi-hollow zeolites that exhibit interesting activity for CO oxidation at room temperature