Evaluation of the photoprotective role of quercetin to selected light-adapted and shade-tolerant plant species

Plants respond to different light intensities depending on their genetic make-up, mutation and other environmental conditions. Mikania micrantha, Clidemia hirta, and Tetracera sarmentosa were selected so as to analyse how varying light intensity affects some gas exchange characteristics, pigment and production of total flavonoid content. Besides, the study was aimed at evaluating the photoprotective role of quercetin to the selected plants, in addition to correlating how the production of flavonoids affects the plants photosynthesis. The photosynthetic rates of the selected plants were determined using LI-6400. The chlorophyll, carotenoid, anthocyanin, flavonoid, antioxidant enzymes, malondialdehyde, soluble sugar and soluble protein contents were quantified using spectroscopic techniques. Quercetin was quantified using high-performance liquid chromatography (HPLC). Sun-exposed plants were having the maximum photosynthesis and quercetin content compared with semi-shaded or fully shaded plants. The highest quercetin content was recorded for sun-exposed C. hirta (0.950 ± 0.023 μg/ml) while the lowest was recorded for shaded T. sarmentosa (0.13 ± 0.007 μg/ml). The highest oxidative stress was recorded for sun-exposed T. sarmentosa (6.19 ± 019 μg/ml) which was also having the lowest quantum efficiency of photosystem II (0.509 ± 0.003). Superoxide dismutase activity was lowest under sun-exposed C. hirta (1.86 ± 0.06 U/mg protein), while peroxidase and catalase were lowest under Sun-exposed T. sarmentosa (59.59 ± 2.67 and 3.75 ± 0.17) U/mg protein respectively. The result obtained makes it possible to accept the generated hypothesis of the study because the quercetin content was higher when the antioxidant enzymes of the plants were low. This leads to a conclusion that increase in the production of secondary metabolites at high light intensity is not due to high CO2 assimilation rate, but rather due to the production of photoprotective metabolites to conquer the light stress

Effects of Sintering Temperatures on Microstructures and Mechanical Properties of Sn4.0Ag0.5Cu1.0Ni Solder Alloy

This research was carried out to investigate the effects of sintering temperature on the properties of Sn-4.0Ag-0.5Cu-1.0Ni solder alloy by varying the temperatures. The Sn-4.0Ag-0.5Cu-1.0Ni solder alloy was prepared by using powder metallurgy method by press and sinter routes. 99.9% of pure Sn, Ag, Cu and Ni powder were used in this research where the pre-mixed powder undergoing milling process for 6 hours using a planetary ball machine. Hydraulic press machine was used to compact the solder powder at identically 5 tons(125 bars) for all samples. Five different temperatures of sintering specifically at 120℃, 150℃, 180℃, 220℃ and 250℃ were used. Characterizations on the microstructures such as grain size, thickness of intermetallic compound and, wettability angle were carried out using Scanning Electron Microscopy. Meanwhile, properties of the solder alloy were also evaluated through hardness and tensile test. It is expected that sintering process could be able to improve the strength of the solder joint by decreasing the intermetallic compound grain size. So far, most papers commonly used 180℃ as their sintering parameter without anyone providing the promising findings and various effects of the temperature onto solder. Therefore, this work is conducted to make a clarification and be the pilot study for the next sintering works for soldering. This paper reports experimental results of properties of Sn-4.0Ag-0.5Cu-1.0Ni solder alloy at different sintering temperatures

Exploration dive finding the frogfish

A couple months back, my team and I went to Perhentian Island in Terengganu for a project called exploration dive. We were assisted by Mr Azharil Art from D’Lagoon Dive Centre, which was recommended by Mr Saiful Bahri Yakup, our team member who is a very well experienced diving instructor. We spent quite some time there with a few numbers of dive trip pursuing research related to marine life and the underwater environment. Nonetheless, this writing will only enumerate our work focusing on frogfish, including its behaviour, habitat, and species

Commercial Diving A Career Path Worths a Consideration

Commercial diving is categorised under a professional diving practice where it enables divers who are involved with any underwater jobs such as construction, engineering, industrial, repair, and maintenance, being carried out offshore and on land

14 UMPSA students participate in Introduction to Underwater Welding Programme

BANGI, 21 August 2023 – A total of 14 Universiti Malaysia Pahang Al-Sultan Abdullah (UMPSA) students recently participated in the Introduction to Underwater Welding Programme in Bangi, Selangor

UMPSA anjur Program Jurulatih Renang Tahap 1 dan Penyelamatan Di Air

SHAH ALAM, 25 September 2023 - Fakulti Teknologi Kejuruteraan Mekanikal dan Automotif (FTKMA), Universiti Malaysia Pahang Al-Sultan Abdullah (UMPSA) dengan kerjasama Aquasplash Academy telah menganjurkan program Jurulatih Renang Tahap 1 dan Penyelamatan Di Air baru-baru ini

Mengharungi gelombang Kepelbagaian cabaran dan keseronokan renang di perairan terbuka

Aktiviti renang di perairan terbuka kian mendapat tempat dalam kalangan peminat sukan air di Malaysia. Ia menawarkan pengalaman yang sangat unik dengan cabaran yang berbeza berbanding renang di kolam. Perenang di perairan terbuka harus menghadapi pelbagai elemen alam semulajadi seperti arus yang kuat serta cuaca yang tidak menentu. Namun, bagi mereka yang meminati aktiviti ini, nilai kepuasan serta keseronokan yang diperoleh adalah tidak terbanding

UMPSA organises Level 1 Swimming Coach and Water Rescue Programme

SHAH ALAM, 25 September 2023 - The Faculty of Mechanical and Automotive Engineering Technology (FTKMA), Universiti Malaysia Pahang Al-Sultan Abdullah (UMPSA) in collaboration with Aquasplash Academy recently organised a Level 1 Swimming Coach and Water Rescue programme

The Effectiveness of Bismuth Addition to Retard the Intermetallic Compound Formation

The aim of this paper is to study the effectiveness of bismuth addition in the solder alloy to retard the intermetallic compound formation and growth. In this study, three categories of solders such as Sn-4Ag-xCu (x = 0.5, 0.7, 1.0) and Sn-4Ag-0.5Cu-xBi (x = 0.1, 0.2, 0.4) were used. Ni/Au surface finish substrates were dipped into the molten solder at a temperature of 180-190 oC and allowed to cool at room temperature. The intermetallic compound (IMCs) were subjected to the characterization in terms of composition and morphology. The IMC phases were identified by energy dispersive x-ray (EDX), whereas the optical microscope and scanning electron microscopy (SEM) were used to observe microstructure evolution of the solder joint. The results clearly showed that copper concentration dependency was high during the reflow stage. Besides, only Ni3Sn4 and Ni3Sn2 were detected for all copper concentrations. The addition of Bi was found to have no significant effect on the type of IMCs formed, but yet the grain became further refined

14 pelajar UMPSA sertai Program Pengenalan Kimpalan Bawah Air

BANGI, 21 Ogos 2023 – Seramai 14 orang pelajar Universiti Malaysia Pahang Al-Sultan Abdullah (UMPSA) telah menyertai Program Pengenalan Kepada Kimpalan Bawah Air di Bangi, Selangor baru-baru ini