Acoustic properties of lightweight foamed concrete with eggshell waste as partial cement replacement material

Nowadays, almost every industry needs to undergo green and sustainable industrial revolution due to pollutions like waste dumping and noise that deteriorating the environment. Therefore, feasibility study on application of eggshell waste as partial cement replacement in lightweight foamed concrete was conducted by aiming to solve environmental and acoustical issues, i.e. reduce eggshell waste and improve acoustic properties. In this study, compressive strength and acoustic properties of 1300 kg m-3 lightweight foamed concrete with and without 5% eggshell powder as partial cement replacement material were tested. Optimal water to cement ratio of 0.6 was obtained for acoustic properties test by comparing compressive strength result. The result shows that application eggshell powder has generally reduced 7 days compressive strength but improved 28 days compressive strength, and either improve or maintain acoustics properties, in which lightweight foamed concrete that containing eggshell powder has improved noise reduction coefficient at testing ages of 7, 28, and 90 days and improved sound transmission class at testing age of 56 and 90 days. Based on these results, 5% of eggshell powder is feasible to be incorporated into lightweight foamed concrete as partial cement replacement material for sound insulation and strength development purposes

Upper limits on the strength of periodic gravitational waves from PSR J1939+2134

The first science run of the LIGO and GEO gravitational wave detectors presented the opportunity to test methods of searching for gravitational waves from known pulsars. Here we present new direct upper limits on the strength of waves from the pulsar PSR J1939+2134 using two independent analysis methods, one in the frequency domain using frequentist statistics and one in the time domain using Bayesian inference. Both methods show that the strain amplitude at Earth from this pulsar is less than a few times $10^{-22}$.Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July 200

Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers

We study frequency dependent (FD) input-output schemes for signal-recycling interferometers, the baseline design of Advanced LIGO and the current configuration of GEO 600. Complementary to a recent proposal by Harms et al. to use FD input squeezing and ordinary homodyne detection, we explore a scheme which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are sub-optimal among all possible input-output schemes, provide a global noise suppression by the power squeeze factor, while being realizable by using detuned Fabry-Perot cavities as input/output filters. At high frequencies, the two schemes are shown to be equivalent, while at low frequencies our scheme gives better performance than that of Harms et al., and is nearly fully optimal. We then study the sensitivity improvement achievable by these schemes in Advanced LIGO era (with 30-m filter cavities and current estimates of filter-mirror losses and thermal noise), for neutron star binary inspirals, and for narrowband GW sources such as low-mass X-ray binaries and known radio pulsars. Optical losses are shown to be a major obstacle for the actual implementation of these techniques in Advanced LIGO. On time scales of third-generation interferometers, like EURO/LIGO-III (~2012), with kilometer-scale filter cavities, a signal-recycling interferometer with the FD readout scheme explored in this paper can have performances comparable to existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi

Search for gravitational wave bursts in LIGO's third science run

We report on a search for gravitational wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets subsecond bursts in the frequency range 100-1100 Hz for which no waveform model is assumed, and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published in Classical and Quantum Gravit

Searching for a Stochastic Background of Gravitational Waves with LIGO

The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is $\Omega_{\rm GW} < 6.5 \times 10^{-5}$. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure

Quantum state preparation and macroscopic entanglement in gravitational-wave detectors

Long-baseline laser-interferometer gravitational-wave detectors are operating at a factor of 10 (in amplitude) above the standard quantum limit (SQL) within a broad frequency band. Such a low classical noise budget has already allowed the creation of a controlled 2.7 kg macroscopic oscillator with an effective eigenfrequency of 150 Hz and an occupation number of 200. This result, along with the prospect for further improvements, heralds the new possibility of experimentally probing macroscopic quantum mechanics (MQM) - quantum mechanical behavior of objects in the realm of everyday experience - using gravitational-wave detectors. In this paper, we provide the mathematical foundation for the first step of a MQM experiment: the preparation of a macroscopic test mass into a nearly minimum-Heisenberg-limited Gaussian quantum state, which is possible if the interferometer's classical noise beats the SQL in a broad frequency band. Our formalism, based on Wiener filtering, allows a straightforward conversion from the classical noise budget of a laser interferometer, in terms of noise spectra, into the strategy for quantum state preparation, and the quality of the prepared state. Using this formalism, we consider how Gaussian entanglement can be built among two macroscopic test masses, and the performance of the planned Advanced LIGO interferometers in quantum-state preparation

Exploring the connection between the testing of reading and literacy: the case of the MUET

The Malaysian University English Test (MUET), introduced in 1999, is a potentially high-stakes test because of the fact that it is a mandatory requirement for admission into public universities. It was introduced with the aim of bringing about a higher level of English proficiency, especially crucial for those entering university. The paper focuses on the impact of the Reading component on literacy, and examines four factors that are perceived to affect the impact of the MUET, namely: 1) the perceived status of the MUET, 2) the sociopolitical situation, 3) the teacher/teaching, and 4) the test construct. It concludes that the reading construct in the MUET Reading component is inadequately operationalized and suggests that the construct be reviewed in the light of long-term literacy goals

Investigating the undergraduate experience of assessment in higher education

This paper reports on the preliminary findings of a doctoral study in progress, which is situated in the context of quality in higher education, and is premised on the view that the student learning experience is ultimately the most meaningful and lasting measure of academic quality. The literature on assessment in higher education clearly places assessment at the heart of student learning and it is claimed that “the truth about an educational system” may be discovered by examining its assessment procedures (Rowntree, 1987, p.1). Using a qualitative case study approach, the study aims to reveal the values inherent in assessment, to show how these are conveyed through institutional discourses and through practices of lecturers, and how students’ learning behaviour may be affected by their perspectives of assessment. Data gathering activities for the entire doctoral research include focus group discussions and individual interviews with finalyear undergraduates, interviews with their lecturers, observations of lectures and classroom assessments, examination of documents related to the course descriptions and assessment, as well as a study of the administrative and procedural aspects of assessment which are part of the assessment praxis. The emerging themes reported here, based solely on the analysis of two of the focus group discussions, indicate how assessment praxis in higher education seems to be a reproduction of dominant power structures that have inculcated patterns of student passivity in learning

English use as an identity marker among Malaysian undergraduates

The English language, a legacy of the British colonialists, has been indelibly woven into the history of Malaysia, and because of its pervasive influence through its role in the education system, it is an important part of the identity construction of those who have gone through the system. This paper reports on the qualitative findings of a study investigating the impact of English on the sociocultural identity construction of young adult Malaysians. The data were obtained from interviews conducted with 20 Malaysian undergraduates from both public and private universities. English is one of the languages in their linguistic repertoire. The demographic composition of the respondents reflects in general the cultural and linguistic diversity of Malaysia. The paper will focus on how the use of English among these university students is perceived as an identity marker that enhances the perception of their personal and social status, and how its use may sometimes be used as the basis by members of the same ethnic community for “othering” them. The paper concludes by suggesting that since competence in the use of English is basically perceived as a form of cultural capital, a move towards enhancing English use among students within a policy that strongly advocates multilingualism is the way towards developing a more inclusive moderate sociocultural identit

The English Language and its impact on identities of multilingual Malaysian undergraduates

Despite the increasing prominence of English as a world lingua franca, there is little research on how the use of English affects the identities of Malaysian speakers. Asmah Haji Omar observed that interest in language and identity seemed to be confined to studies on national identity. A doctoral study by Lee Su Kim of the identity of Malaysian speakers of English found that there was resentment in certain localized contexts amongst the Malay respondents in the study towards the use of English. Expressions of resentment and ambivalence towards the use of the English language were also prevalent amongst the non-Malay respondents within certain contexts. This paper presents the findings of a qualitative research study which sets out to investigate the impact of English on the identities of young Malaysian undergraduates in selected private and public universities in Malaysia. Using qualitative methods, this research study essentially takes off from Lee Su Kim’s doctoral research study, and aims to explore on a larger scale the role of English in the identity construction of a younger Malaysian cohort from both public and private universities. The findings presented here are from a few selected case studies that provide the qualitative data. The discussion will focus on how different multilingual Malaysian undergraduates regard English vis a vis the other languages in their repertoire and how it has affected their identity constructions and everyday negotiations. Three dominant themes arising from the findings will be discussed, 1) Multilingualism with English emerging as the dominant language, 2) English viewed as a pragmatic language and a language of empowerment, and 3) Varying degrees of ‘othering’