Kinetics and mechanism of the reaction between atomic chlorine and dimethyl selenide; comparison with the reaction between atomic chlorine and dimethyl sulfide

Dimethyl selenide is the most abundant gaseous selenium species in marine environments. In this work, the value of the rate coefficient for the gas-phase reaction between dimethyl selenide and Cl atoms has been determined for the first time. The value of the second-order rate coefficient obtained was (5.0±1.4)×10–10 cm3 molecule–1 s–1. The very fast nature of the reaction means that, when estimating the lifetime of dimethyl selenide in the atmosphere, loss due to reaction with Cl atoms should be considered along with loss due to reaction with O3 and with OH and NO3 radicals. Analysis of the available kinetic data suggests that at 760 Torr the dominant reaction pathway for the reaction of Cl atoms with dimethyl selenide will be the addition of Cl to the Se atom forming an adduct of the type CH3Se(Cl)CH3. Theoretical calculations, at the B3LYP/6-311++G(2df,p)//B3LYP/6-311++G(d,p) level of theory, show that at 298 K the value of rH for the formation of the adduct is –111.4 kJ mol–1. This value may be compared to –97.0 kJ mol–1, the value calculated for rH for the formation of the analogous sulfur adduct, CH3S(Cl)CH3, following the reaction between Cl atoms and dimethyl sulfide. Variational RRKM theory was used to predict the thermal decomposition rates of the two adducts back to starting materials. The estimated rate constant for the decomposition of the selenium adduct to the reactants is 5×10–5 s–1, compared to 0.02 s–1 in the case of the sulfur adduct. However, our calculations suggest that the CH3Se(Cl)CH3 adduct, which is initially formed highly excited, will not be stabilised under atmospheric conditions, but rather will decompose to yield CH3SeCl and CH3, a process that is calculated to be exothermic with respect to the initial reactants by 5.8 kJ mol–1. The formation of CH3SCl and CH3 from the sulfur adduct, on the other hand, is endothermic by 20.8 kJ mol–1 with respect to the initial reactants, and is thus not expected to occur

The Economic Impact of Migration – Productivity Analysis for Spain and the UK

As a consequence of increased internationalization over the past 20 years labour has become increasingly mobile, and yet the implications for firm and industry performance have been largely ignored. This paper explores the direct economic consequences of immigration on host nations’ productivity performance at a sectoral level. We consider its impact in two very different European countries, Spain and the UK. Whilst the UK has traditionally had a substantial in-flow of migration, for Spain, the phenomenon is much more recent. The paper provides an overview of the role played by immigration on per capita income, highlighting the importance of demographic differences. We then go on to analyze the role of migration on productivity using two different approaches: i) growth accounting methodology and ii) econometric estimation of a production function. Our findings indicate that migration has had very different implications for Spain and the UK, migrants being more productive than natives in the UK but less productive than natives in Spain. This may in part be a function of different immigration policies, particularly related to the skill requirements on entry, but also in part a feature of the host nations’ ability to ‘absorb’ foreign labour.Migration, productivity

APLIKASI PEMILIHAN BIDANG MINAT SISWA SMA MENGGUNAKAN METODE ANALYTICAL HIERARCHY PROCESS STUDY KASUS (SMA KR. YBPK-1 SURABAYA)

Seiring dengan perkembangan dunia teknologi dan pendidikan Para siswa SMA kelas X yang akan melanjutkan pendidikannya di tingkat selanjutnya harus memutuskan pilihan jurusan, ini merupakan sesuatu yang cukup sulit diputuskan oleh kebanyakan siswa SMA. Kebanyakan siswa SMA sekarang sulit untuk menentukan minat memilih jurusan pada waktu SMA. maka demikian penyelesaian studi kasus ini menggunakan metode ANALYTICAL HIERARCHY PROCESS dengan menunjukan 3 kriteria (IPA, IPS, BAHASA), membuat nilai bobot, Melakukan perhitungan matrix nilai bobot dan menentukan local priority, Membuat tabel interval tiap mata pelajaran, Mengitung matrix tiap interval untuk mencari nilai total dan nilai local priority di tiap mata pelajaran, Menghitung hasil akhir nilai global priority. Setelah dilakukan uji coba dari Sistem Pemilihan Bidang Minat Pada Jurusan SMA maka dapat diambil kesimpulan, dari hasil penelitian menunjukan bahwa metode AHP dapat digunakan untuk menentukan jurusan dengan rata – rata akurasi 78%, dengan data akurasi IPA = 70%, IPS= 75%, BAHASA = 90%. Pada pembuatan aplikasi ini terdapat saran Untuk pengembangan lebih lanjut aplikasi ini, bisa dikembangkan lagi dengan menambahkan bidang minat ekstakulikuler jadi tidak hanya dari akademik saja, Untuk pengembangan lebih lanjut aplikasi Sistem pemilihan Bidang Minat ini terdapat latihan soal untuk memulai penjurusan akademik. Kata kunci : Perangkat lunak, Bidang Minat SM

Diseño y evaluación de una secuencia de enseñanza para introducir los conceptos de sustancia y reacción química en la educación secundaria

Este trabajo propone una secuencia de enseñanza que facilite el aprendizaje de los conceptos de sustancia, sustancia simple, compuesto y reacción química. La secuenciación y organización de los contenidos se fundamenta en un análisis histórico de la construcción de la teoría atómica daltoniana y la secuencia de enseñanza se completa mediante dos programas de actividades basados en el modelo de aprendizaje como investigación orientada. La eficacia de la secuencia de enseñanza se evaluó mediante un diseño postest en el que se comparaban las respuestas de los alumnos de los grupos experimentales (N=187) con las formuladas por estudiantes de grupos de control que no habían sido tratados (N= 381). Los resultados muestran que la utilización del programa ha favorecido un mayor aprendizaje en los estudiantes de los grupos experimentales

Conceptual design of the EU-DEMO dual coolant lithium lead equatorial module

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Within the framework of EUROfusion Program, the Dual Coolant Lithium Lead (DCLL) is one of the four EU breeder blanket concepts that are being investigated as candidates for DEMO. DCLL uses PbLi as the main coolant, tritium breeder, tritium carrier, and neutron multiplier. The main structures, including the first wall, are cooled with helium. The EU program proposed for the next years will consider a DCLL version limited to 550 °C in order to allow the use of conventional materials and technologies. During the first year of EUROfusion activities, a draft design of the DCLL has been proposed. The main blanket performances were adapted to the new specifications and the CAD model of DEMO. The breeder zone has been toroidally divided into four parallel PbLi circuits, separated through stiffening grid radial walls. The PbLi flow routing has been designed to maximize the amount of thermal power extracted by flowing PbLi and to avoid the occurrence of reverse flows due to volumetric heating. Thermal hydraulics, magnetohydrodynamic and neutronics calculations have been performed for the first draft design. The new DCLL design employs Eurofer-alumina-Eurofer sandwich as flow channel insert (FCI).Postprint (published version

Dispatcher3 D4.2 - Prototype package (first release) - User manual

This deliverable along with deliverable D4.1. Technical documentation first release consists of the release of the first prototype of Dispatcher3. The release consists of the binaries and Docker version of the prototype (sent to the Topic Manager). The first release prototype package consists of a set on individual machine learning models which can be executed using Jupyter notebooks. It also includes the integration of the outcome of some of these individual models into a visualisation which would be part of the advice generator to provide high-level information to the end users. All models described in the Deliverable D4.1 will be available and executable in this release. Data required to run the models (with some examples) are also provided. If data are public raw sample values are provided, otherwise pre-computed features are delivered so that the models can be run on individual flight examples. The prototypes can be run using local data (provided in the release) or with data stored in cloud storage (Amazon Web Services (AWS)). This deliverable serves as a manual for the execution of the first release prototype software

Effective Free Energy for Individual Dynamics

Physics and economics are two disciplines that share the common challenge of linking microscopic and macroscopic behaviors. However, while physics is based on collective dynamics, economics is based on individual choices. This conceptual difference is one of the main obstacles one has to overcome in order to characterize analytically economic models. In this paper, we build both on statistical mechanics and the game theory notion of Potential Function to introduce a rigorous generalization of the physicist's free energy, which includes individual dynamics. Our approach paves the way to analytical treatments of a wide range of socio-economic models and might bring new insights into them. As first examples, we derive solutions for a congestion model and a residential segregation model.Comment: 8 pages, 2 figures, presented at the ECCS'10 conferenc

Multi-resolution shape-based image retrieval using Ridgelet transform

Complicated shapes can be effectively characterized using multi-resolution descriptors. One popular method is the Ridgelet transform which has enjoyed very little exposure in describing shapes for Content-based Image Retrieval (CBIR). Many of the existing Ridgelet transforms are only applied on images of size M×M. For M×N sized images, they need to be segmented into M×M sub-images prior to processing. A different number of orientations and cut-off points for the Radon transform parameters also need to be utilized according to the image size. This paper presents a new shape descriptor for CBIR based on Ridgelet transform which is able to handle images of various sizes. The utilization of the ellipse template for better image coverage and the normalization of the Ridgelet transform are introduced. For better retrieval, a template-option scheme is also introduced. Retrieval effectiveness obtained by the proposed method has shown to be higher compared to several previous descriptors