Contributions of Ibn Al-Haytham on optics

The objective of this cpapter is to explore optics in view of Ibn Haytham's work on optics.The methodology adopted is based on data collected from articles, journals and books. This chapter investigates the contribution of Ibn AI-Haytham in optics and related fields. Moreover, the main focus of this chapter is to discuss optics theory by Ibn AlHaytham.nThe significance of this is that it provides knowledge on optics theory based on Ibn Haytham's wor

Reduction of low grade iron ore pellet using palm kernel shell

Effective use of local iron ore and biomass waste as energy and material resources in iron making is an interesting economic prospect since Malaysia imports iron ore to supply its domestic steel consumption while there is an abundance of biomass waste from the palm oil industry. In this work, a composite pellet made of Malaysian iron ore with palm kernel shell (PKS) waste was subjected to reduction tests using an electric tube furnace to investigate the effect of temperature and PKS content on reduction rate. Several iron ore samples taken from different mining locations were subjected to thermal and X-ray diffraction (XRD) analysis. The rate of iron ore reduction increased with increasing temperature up to 900 °C. XRD analysis revealed that the original iron ore mainly contains iron oxide hydrate and was converted into simple hematite after heating and then become magnetite after reduction. The Fe content in the original ore increased almost 12% when 40 wt% of PKS was used. The iron oxide was successfully reduced to magnetite and small amount of wustite when up to 20 wt% of PKS was present in the mixture. Besides, 20 wt% of PKS in reduction process can reduce CO2 emissions by almost 18.69 wt% as well as decrease carbon consumption by 19.78 wt%. Thus, the utilization of biomass as a reducing agent for low grade iron ore reduction is an attractive method for upgrading iron ore as well as reducing CO2 emissions

Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873–1173 K. The extent of reduction was estimated on the basis of mass loss, and the magnetization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic ceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was partially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic properties

Effects of petroleum-based oils as dispersing aids on physicochemical characteristics of magnetorheological elastomers

This paper investigated the effects of petroleum-based oils (PBOs) as a dispersing aid on the physicochemical characteristics of natural rubber (NR)-based magnetorheological elastomers (MREs). The addition of PBOs was expected to overcome the low performance of magnetorheological (MR) elastomers due to their inhomogeneous dispersion and the mobility of magnetic particles within the elastomer matrix. The NR-based MREs were firstly fabricated by mixing the NR compounds homogeneously with different ratios of naphthenic oil (NO), light mineral oil (LMO), and paraffin oil (PO) to aromatic oil (AO), with weight percentage ratios of 100:0, 70:30, 50:50, and 30:70, respectively. From the obtained results, the ratios of NO mixed with low amounts of AO improved the material physicochemical characteristics, such as thermal properties. Meanwhile, LMO mixed the AO led to the best results for curing characteristics, microstructure observation, and magnetic properties of the MREs. We found that the LMO mixed with a high content of AO could provide good compatibility between the rubber molecular and magnetic particles due to similar chemical structures, which apparently enhance the physicochemical characteristics of MREs. In conclusion, the 30:70 ratio of LMO:AO is considered the preferable dispersing aid for MREs due to structural compounds present in the oil that enhance the physicochemical characteristics of the NR-based MREs

Analysis of stock market reaction in Malaysia during Covid-19 pandemic via ARIMA

Investment has become a major money-making business in this world through investment in financial markets, stock markets, and forex. There is uncertainty about which stocks to buy during a pandemic like Covid-19. Poor investment choices will affect the profitability of the investors, shifting their risk appetite to be more defensive. Thus, this research is carried out to study the movement of stocks for the year 2020 in Malaysia based on the data obtained from Yahoo Finance. The objective is to provide investors with a guide to investing efficiently during a pandemic. This study investigates how Covid-19 impacts the rate of growth or reduction of stocks so that the performance of the stocks can be forecasted in the future. The moving average method is used to analyze the trend of the stock by comparing the top gainers against the top losers during the periods of pre Covid-19 and Covid-19. The Autoregressive Integrated Moving Average (ARIMA) model studies the autocorrelation function (ACF) graph of selected stocks to further understand the movement of the stocks and compare it to the closing prices of the selected stocks. Based on the findings, it was demonstrated that the quantitative method used could be used to study the effects of a pandemic, as well as the severity of the losses incurred, and profits earned by the industries. The industries that are essential to the country, like pharmaceuticals and rubber manufacturing, are able to maintain their businesses. Moreover, these sectors have profited from the pandemic. The tourism and aviation industries have been hit the hardest by the pandemic, as evidenced by falling stock prices. Thus, it would be wise for investors to invest in an essential sector company during the Covid-19 pandemic

Thermal Stability and Rheological Properties of Epoxidized Natural Rubber-Based Magnetorheological Elastomer

Determination of the thermal characteristics and temperature-dependent rheological properties of the magnetorheological elastomers (MREs) is of paramount importance particularly with regards to MRE applications. Hitherto, a paucity of temperature dependent analysis has been conducted by MRE researchers. In this study, an investigation on the thermal and rheological properties of epoxidized natural rubber (ENR)-based MREs was performed. Various percentages of carbonyl iron particles (CIPs) were blended with the ENR compound using a two roll-mill for the preparation of the ENR-based MRE samples. The morphological, elemental, and thermal analyses were performed before the rheological test. Several characterizations, as well as the effects of the strain amplitude, temperature, and magnetic field on the rheological properties of ENR-based MRE samples, were evaluated. The micrographs and elemental results were well-correlated regarding the CIP and Fe contents, and a uniform distribution of CIPs was achieved. The results of the thermal test indicated that the incorporation of CIPs enhanced the thermal stability of the ENR-based MREs. Based on the rheological analysis, the storage modulus and loss factor were dependent on the CIP content and strain amplitude. The effect of temperature on the rheological properties revealed that the stiffness of the ENR-based MREs was considered stable, and they were appropriate to be employed in the MRE devices exposed to high temperatures above 45 °C

Enhancement of sensitivity of magnetostrictive foam in low magnetic fields for sensor applications

Magnetostrictive materials are usually used in sensor technology since they are sensitive to magnetization and strain. Unfortunately, to date, only a few magnetostrictive materials are being used, as the need for a strong magnetic field (1 T) and not sensitive at a low magnetic field. Thus, in this study, a new magneto-active (MA) polyurethane foam was fabricated to obtain a strain at a low magnetic field corresponding to below 1 T. The in-situ fabrication of the MA foam was carried out with various compositions of carbonyl iron particles (CIPs), particularly at 35, 45, 55, 65 and 75 wt%. An analysis of the magnetic properties revealed that all the MA foams showed high magnetic saturation with low remanence values. Furthermore, the MA foam of 75 wt% showed the highest magnetostrictive strain of 1.66% at 0.45 T. The sensitivity of the MA foam is 0.0146%/mT with 42% of improvement. Analyses show MA foam of 75 wt% had a low density, biggest pores and long struts that might have led to high flexibility for elongation to produce a high strain percentage within the practical magnetic field range. Hence, this MA foam can be further utilized for sensor applications

Magnetization of low grade iron ore using empty fruit bunch ash

Malaysian low grade iron ore is unsuitable as raw material for domestic iron making due to high energy consumption which correspond to low iron content. The present agricultural residues from domestic palm oil industry are attractive proposition as energy source for iron making. This work describes the use of ash produced from pyrolysis of palm oil Empty Fruit Bunch (EFB) to magnetize the low grade iron ore. A briquette composite of iron ore and ash is subjected to reduction process using an electric tube furnace under argon atmosphere at 873K and 1073K. The ore was successfully magnetized through reduction process as carbon in EFB ash act as reductant. The results showed that the reduction degree was greatly enhanced with increasing of temperature and time. The significant phase changes of iron ore from a non-magnetic material of goethite to a strong magnetic material of magnetite was detected in XRD patterns. The process indicated that substitution of coal with EFB ash as an energy source has a potential in replacing fossil fuel by magnetizining the iron ore as well as encourage waste management control