The National Small Wind Turbine Centre

In August 2008, the Federal government announced funding for a National Small Wind Turbine Centre (NSWTC) to be operated by the Research Institute of Sustainable Energy (RISE), based at Murdoch University in Perth, Western Australia. The aim of the NSWTC is to promote the small wind turbine (SWT) market and industry in Australia by providing services in the areas of Testing, Standards and Labelling, Professional Development and Training, and Research. This paper summarises the work that has been carried out to date by the NSWTC in the area of Standards and Labelling. Existing certification and labelling schemes for SWTs are summarised and an overview is given of the NSWTC participation in the International Energy Agency (IEA) Task 27, a task aimed at research that will advance standards, improve the quality of SWT testing around the globe and lead to an international consumer label for SWTs. Options for certification and labelling for the emerging Australian SWT industry are analysed and the idea of introducing an Australian consumer label for SWTs is discussed

Exact equations for smoothed Wigner transforms and homogenization of wave propagation

The Wigner Transform (WT) has been extensively used in the formulation of phase-space models for a variety of wave propagation problems including high-frequency limits, nonlinear and random waves. It is well known that the WT features counterintuitive 'interference terms', which often make computation impractical. In this connection, we propose the use of the smoothed Wigner Transform (SWT), and derive new, exact equations for it, covering a broad class of wave propagation problems. Equations for spectrograms are included as a special case. The 'taming' of the interference terms by the SWT is illustrated, and an asymptotic model for the Schroedinger equation is constructed and numerically verified.Comment: 16 pages, 8 figure

Diagrammatic approach in the variational coupled-cluster method

Recently, as demonstrated by an antiferromagnetic spin-lattice application, we have successfully extended the coupled-cluster method (CCM) to a variational formalism in which two sets of distribution functions are introduced to evaluate Hamiltonian expectation. We calculated these distribution functions by employing an algebraic scheme. Here we present an alternative calculation based on a diagrammatic technique. Similar to the method of correlated-basis functionals (CBF), a generating functional is introduced and calculated by a linked-cluster expansion in terms of diagrams which are categorized and constructed according to a few simple rules and using correlation coefficients and Pauli exclusion principle (or Pauli line) as basic elements. Infinite resummations of diagrams can then be done in a straightforward manner. One such resummation, which includes all so-called ring diagrams and ignores Pauli exclusion principle, reproduces spin-wave theory (SWT). Approximations beyond SWT are also given. Interestingly, one such approximation including all so-called super-ring diagrams by a resummation of infinite Pauli lines in additional to resummations of ring diagrams produces a convergent, precise number for the order-parameter of the one-dimensional isotropic model, contrast to the well-known divergence of SWT. We also discuss the direct relation between our variational CCM and CBF and discuss a possible unification of the two theories.Comment: 18 pages, 9 figure

Kehidupan Harun a.s. dan Dakwahnya

Allah SWT has informed through the Qur'an many stories of the previous people, whether it is the story of the people who are obedient to Allah SWT or the story of the people who do not obey. For every Ummah, Allah SWT has sent prophets and apostles to preach so that they always obey Allah SWT. Likewise, Allah SWT has sent Musa a.s and Harun a.s to the Israel generation and the Qibthi who inhabited Egypt. In carrying out his da'wah, Moses or Musa a.s had prayed for Allah SWT to make Harun a.s. be appointed as a prophet and then Allah SWT granted. So Allah SWT gave him the advantage of eloquence in speech and brilliance in thinking so that he could help Musa a.s. in his da'wah. This short article will specifically discuss the story of the Prophet Harun a.s as narrated in the Qur'an. ABSTRAKAllah SWT telah menginformasikan melalui Al-Qur'an banyak kisah orang-orang terdahulu, baik itu kisah orang-orang yang taat kepada Allah SWT maupun kisah orang-orang yang tidak taat. Bagi setiap umat, Allah SWT telah mengutus para nabi dan rasul untuk berdakwah agar selalu taat kepada Allah SWT. Demikian juga Allah SWT telah mengutus Musa a.s dan Harun a.s kepada generasi Israel dan Qibthi yang mendiami Mesir. Dalam menjalankan dakwahnya, Musa atau Musa a.s telah berdoa kepada Allah SWT agar Harun a.s. diangkat menjadi nabi dan kemudian dikabulkan Allah SWT. Maka Allah SWT memberinya kelebihan kefasihan dalam berbicara dan kecemerlangan dalam berpikir sehingga ia dapat membantu Musa a.s. dalam dakwahnya. Artikel singkat ini secara khusus akan membahas kisah Nabi Harun a.s sebagaimana diriwayatkan dalam Al-Qur'an

Hadis Tentang Eksistensi Allah SWT

Efforts to prove the existence of God is an important endeavor, not only to convince other people (read: atheists and agnostics) that God exists rationally, but also to pave the way for claims to the truth of revelation, if the arguments are strong. However, efforts to prove the existence of God through philosophy are also not without risk, because if that effort fails, in the sense that it does not have strong and irrefutable arguments, then it becomes a reason for an atheist or agnostic to stick to his stance: not believing in the existence of God. The hadith about the existence/form of Allah SWT after being studied and traced from the path of Imam Bukhari and Ahmad is sourced from Imran bin Husein with continued sanad and tsiqqah, starting from the initial sanad to the end of the sanad. Likewise from the point of view of the matan it also looks authentic because there is no apparent conflict with the Qur'an. In understanding this hadith, the form of Allah SWT described in the hadith is monotheism and the beginning and the end