Scanning laser source and scanning laser detection techniques for different surface crack geometries

Standard test samples typically contain simulated defects such as slots machined normal to the surface. However, real defects will not always propagate in this manner; for example, rolling contact fatigue on rails propagates at around 25º to the surface, and corrosion cracking can grow in a branched manner. Therefore, there is a need to understand how ultrasonic surface waves interact with different crack geometries. We present measurements of machined slots inclined at an angle to the surface normal, or with simple branched geometries, using laser ultrasound. Recently, Rayleigh wave enhancements observed when using the scanning laser source technique, where a generation laser is scanned along a sample, have been highlighted for their potential in detecting surface cracks. We show that the enhancement measured with laser detector scanning can give a more significant enhancement when different crack geometries are considered. We discuss the behaviour of an incident Rayleigh wave in the region of an angled defect, and consider mode-conversions which lead to a very large enhancement when the detector is close to the opening of a shallow defect. This process could be used in characterising defects, as well as being an excellent fingerprint of their presence

Non-contact ultrasonic detection of angled surface defects

Non-destructive testing is an important technique, and improvements are constantly needed. Surface defects in metals are not necessarily confined to orientations normal to the sample surface; however, much of the previous work investigating the interaction of ultrasonic surface waves with surface-breaking defects has assumed cracks inclined at 90° to the surface. This paper explores the interaction of Rayleigh waves with cracks which have a wide range of angles and depths relative to the surface, using a non-contact laser generation and detection system. Additional insight is acquired using a 3D model generated using finite element method software. A clear variation of the reflection and transmission coefficients with both crack angle and length is found, in both the out-of-plane and in-plane components. The 3D model is further used to understand the contributions of different wavemodes to B-Scans produced when scanning a sample, to enable understanding of the reflection and transmission behaviour, and help identify angled defects. Knowledge of these effects is essential to correctly gauge the severity of surface cracking

Establishment and characterization of two human breast carcinoma cell lines by spontaneous immortalization: Discordance between Estrogen, Progesterone and HER2/neu receptors of breast carcinoma tissues with derived cell lines

Background: Breast cancer is one of the most common cancers among women throughout the world. Therefore, established cell lines are widely used as in vitro experimental models in cancer research.Methods: Two continuous human breast cell lines, designated MBC1 and MBC2, were successfully established and characterized from invasive ductal breast carcinoma tissues of Malaysian patients. MBC1 and MBC2 have been characterized in terms of morphology analysis, population doubling time, clonogenic formation, wound healing assay, invasion assay, cell cycle, DNA profiling, fluorescence immunocytochemistry, Western blotting and karyotyping.Results: MBC1 and MBC2 exhibited adherent monolayer epithelial morphology at a passage number of 150. Receptor status of MBC1 and MBC2 show (ER+, PR+, HER2+) and (ER+, PR-, HER2+), respectively. These results are in discordance with histopathological studies of the tumoral tissues, which were triple negative and (ER-, PR-, HER2+) for MBC1 and MBC2, respectively. Both cell lines were capable of growing in soft agar culture, which suggests their metastatic potential. The MBC1 and MBC2 metaphase spreads showed an abnormal karyotype, including hyperdiploidy and complex rearrangements with modes of 52-58 chromosomes per cell.Conclusions: Loss or gain in secondary properties, deregulation and specific genetic changes possibly conferred receptor changes during the culturing of tumoral cells. Thus, we hypothesize that, among heterogenous tumoral cells, only a small minority of ER+/PR+/HER2+ and ER+/PR-/HER2+ cells with lower energy metabolism might survive and adjust easily to in vitro conditions. These cell lines will pave the way for new perspectives in genetic and biological investigations, drug resistance and chemotherapy studies, and would serve as prototype models in Malaysian breast carcinogenesis investigations. © 2012 Kamalidehghan et al.; licensee BioMed Central Ltd

Pleurotus sajor-caju (PSC) Improves Nutrient Contents and Maintains Sensory Properties of Carbohydrate-based Products

The grey oyster mushroom, Pleurotus sajor-caju (PSC), is a common edible mushroom and is now grown commercially around the world for food. This fungus has been broadly used as food or food ingredients in various food products for a long time. To enhance the nutritional quality and sensory attributes of bakery-based products, PSC powder is used in the present study to partially replace wheat flour in baked product formulations. The nutrient content and sensory properties of rice-porridge and unleavened bread (paratha) incorporated with various levels of PSC powder were studied. These food items were formulated with either 0%, 2%, 4% or 6% of PSC powder. Results show PSC powder recorded β-glucan at 3.57g/100g. In sensory evaluation, consumers gave higher score to both rice-porridge and paratha bread containing 2-4% PSC compared to those that are not added with PSC powder. The paratha containing 4% PSC powder can be formulated with the intention in improving overall acceptability of paratha bread. Meanwhile, for rice-porridge, consumers prefer the formulated product added with 4% PSC powder. In conclusion, the addition of PSC powder to partially wheat flour can be recommended for the purpose of enhancing nutritional composition and maintaining the acceptability of carbohydrate-based products

Scanning laser techniques for characterisation of different surface breaking defect geometries

Measurements using a laser scanning system consisting of a pulsed Nd:YAG laser to generate surface ultrasonic waves and an interferometer to detect the surface displacement, are presented for different samples and defect geometries. We show, firstly, details of the interaction of Rayleigh waves in thick samples with machined slots inclined at an angle to the surface normal, or with simple branched geometries, scanning the generation source over the defect (SLLS) or scanning the detection point over the defect (SLD). Secondly, we discuss effects of Lamb waves interacting with V-shaped defects in thin samples. The results from these measurements have shown that the signal enhancement found in the near-field in both cases can be used to position the defect and gain an idea of its geometry, and have shown this to be a suitable fingerprint of the presence of the defect

The Selangor State Assembly oversight and government accountability

Government choices, decisions and actions impacts the lives of a country’s citizens. It is imperative to ensure that every decision made by the legislative body has the best interest of the citizens at heart. The constitution of Malaysia provides that, apart from the parliament, at the state level, the State Assembly is entrusted to accomplish that duty. The Selangor State Assembly (SSA) is the legislative body that oversees the government of Selangor. The SSA follows the parliamentary model of government. This paper attempts to examine the effectiveness of the SSA oversight in ensuring the Selangor state government accountability in relation to the Talam case. The concept of accountability has two facets – answerability and enforcement. This study is an explorative attempt to describe the effectiveness of the SSA oversight used in ensuring government accountability. Matching internal and external oversights with the different forms of accountability must have high enforcement or sanctions capacity for the oversight mechanisms to be effective. This paper will examine the following research questions: a) What are the mechanisms available to ensure the accountability of the SSA; b) Are the mechanisms in place ensuring the government accountability in Selangor; and c) What are the challenges in ensuring government accountability in Selangor and how they are to be resolved. The data of this research paper would mainly be from secondary sources. The work of Pelizzo and Stapenhurst (2014) in legislative oversight and government accountability will be used as the theoretical guideline of this study. Their conceptual model highlighted that legislature under some conditions (context) can perform efficiently and effectively their oversight function (which also depends on the tools at their disposal). Legislative oversight, if effectively performed, can keep government accountable; a greater accountability can lead to a reduction in the level of corruption. Reduced corruption results in improved economic development and living standards. This study reveals the extent of the SSA legislative oversight effectiveness in ensuring the Selangor state government accountability

Optical properties of diamond like carbon films prepared by DC-PECVD

Diamond-like carbon (DLC) thin films were deposited at different substrate temperatures using methane and hydrogen gas in DC-PECVD at 2x10-1Torr. From the light transmission using UV-VIS spectroscopy it was found that the optical transition had changed from allowed indirect transition to allowed direct transition as the substrate temperature increased. The Optical gap increased with temperature, highest of 3.034 eV was observed at 573 K, beyond which it dropped. Colour of the film changed from light brownish to a colourless transparent film in the higher temperature. The Urbach energy decreased from 1.25 eV to 0.75 eV with increasing substrate temperature till 573 K and a slight increase after it. This trend is attributed to change in sp3/sp2 ratio or change in structure. The cluster size decreases with temperature, resulting in larger band gap and the structure more ordered. Similar pattern is also witnessed in the emission spectrum of the photoluminescence

Power-dependent nonlinear optical behaviours of ponceau bs chromophore at 532 nm via z-scan technique

This paper reports on the power-dependent nonlinear optical (NLO) attributes for both nonlinear refractive index, n2 and nonlinear absorption coefficient, β of Ponceau BS (PBS) chromophore, a synthetic organic compound that falls under azo family. Single-beam Z-scan technique was utilized for the nonlinear measurement. Dominant absorption peak is observed in the visible region due to the high conjugation of diazene functional group absorption. The existence of vital vibrational bonds e.g. the azo bond (1576 cm−1) was confirmed via Fourier Transform Infrared Spectroscopy (FTIR). The intermolecular charge transfer (ICT) of delocalized electrons is responsible for the quick nonlinear response of the sample under intense laser excitation. Response from the closed and open aperture Z-scan technique indicates that PBS chromophore exhibits self-defocusing effects with negative sign of n2 and reverse saturable absorption (RSA) in the order of 10−9 and 10−4 respectively. The real and imaginary components of third order susceptibility, χ3 are relatively high in the order of 10−8 and 10-5 respectively under different laser powers (0.12, 0.14, 0.16, 0.18 & 0.20 W). In short, PBS chromophore shows promising features and can be considered as a potential candidate for various NLO applications under low-power laser operation

Simulation study of cooling system for photovoltaic panel using ansys

Photovoltaic or PV system are very important nowadays because of its functionality of absorbing energy of sunlight and convert it to electric energy. By applying the PV panel, it can cut the cost of billing for the users. It also called a green technology because it produces clean of the energy that can avoid from global warming and air pollutant. Despite of the benefits that it produces, the efficiency process of the system depends on how it been take care. The PV panel cannot be exposed to the high temperature of sunlight. If PV panel getting hot, the PV panel system cannot produce a full of its efficiency to user. By applying the cooling system on the PV panel, it can control and reduce the temperature of PV panel when the temperature increase. The simulation run was taken place in this research by using Ansys software. The result shows the reduction of the temperature of PV panel by applying mass flow rate of air and water. The inclination angle also plays a role in the simulation because if the angle of inclination of PV panel exposed more to sunlight it easily can make the PV panel hot. When the values of the mass flow rate increased, the lower the temperature of the PV panel can be achieved

Morphology and composition of strontium calcium aluminate matrix doped with Dy3+

The aim of the present study was to determine the influence of doping rare earth ion on strontium calcium aluminate (CaO-SrO-SiO2-Al2O3). Therefore, the authors have manufactured luminescent material consisting of 40CaO-5SrO-5SiO2-50Al2O3 doped with Dy3+. The compositions have been selected on the basis of chemical stability. Five pellets were prepared with different calcination temperatures and times, namely 400 and 600°C for 1 and 2 h, in order to shed light on their luminescence behaviour. X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy elaborate and characterise the formation of small particle of photoluminescent material in the phosphor matrix host material