The biosynthesis of nanoparticles has been proposed as a cost-effective and environmental friendly alternative to chemical and physical methods. The present study was aimed to characterise Catharanthus roseus (C. roseus)-silver nanoparticles (AgNPs) using a standardised C. roseus aqueous extract. Methods: The standardisation was performed by using Liquid Chromatography/Time-of-Flight ion trap Mass Spectrometry. An optimised C. roseus-AgNPs have been previously synthesised. Further characterisation of C. roseus-AgNPs was evaluated by zeta potential analysis and fourier transform infrared spectroscopy (FTIR). Results: The chromatography analysis has revealed presence of thirteen possible indole alkaloids in C. roseus extract which were lochrovicine, lochnerine, vinleurosine, vindolinine, tabersonine, catharanthine, serpentine, catharosine, vincristine, catharine, ajmalicine, vinleurosine, and vindolicine. Zeta potential analysis exhibited the value at -16.6 mV. FTIR spectrum of C. roseus aqueous extract showed the absorption band at 3210.83 cm-1 (C-H stretch), 2934.11 (C-H bond), 1578.15 (N=O stretch), 1388.76 and 1314.89 (N=O bend), 1119.29 (C-O bond) and 729.94 (C-Cl bond). In comparison, FTIR spectrum of C. roseus-AgNP s showed the absorption band at 2925.01 and 2924.97 (C-H bond), 1622.93 (C-C=C symmetric stretch), 1383.19 and 1384.13 (N-O bend), 1037.92/1038.76/1238.3/1117.2 (C-O bond), 3169.4 (O-H bond), 774.59 and 691.53 (C-Cl bond). Conclusion: The present findings have shown that the C. roseus aqueous extract contains alkaloids that may responsible as reducing and stabilising agents in the synthesis of AgNPs.
Wireless Sensor Technologies (WST) is entering a new phase. Recent advances offer vast opportunities for research and development. On top of that, this is the consequence of the decreasing costs of ownership, the increase of smaller sensing devices in engineering and the achievements in radio frequency technology and digital circuits. The aim of this research was to combine the Wireless Sensor Network with ZigBee technology. It is expected to develop Haze Smart Greenhouse to control the temperature and humidity via remote automation. In addition, a GUI interface will be built to ease in controlling and managing the prototype through computer via wired and wireless technology. This Haze Smart Greenhouse prototype will be proposed to be developed and tested with operational via remote automation.
Kathiravan, Yamunah, Mohd Fahmi Mohamad Amran, Noor Afiza Mat Razali, Mohd Afizi Mohd Shukran, Norshahriah Abdul Wahab, Mohammad Adib Khairuddin, et al.
Privacy has always been a constant concern for many people. Internet users are often worried about the browsing information that is left on their storage media. Web browsers were later introduced with a new feature called private browsing to overcome this issue. The private browsing mode is expected to behave as normal browsing session but without storing any data such as browser cookies, history, cache and passwords on the local machine. Unfortunately, previous researchers concluded web browser often failed to provide the intended privacy protection to their user. Along the way of this reviewing process, the weakness and downside of previous web browser vendors have been identified.