Role of Electrode Binder on Contact Formation between La0.6Sr0.4CoO3-? Cathode and Yttrium Doped Cerate-Zirconate Solid Electrolyte

Powder of La0.6Sr0.4CoO3-? (LSCO) was synthesized by a combined citrate-EDTA synthesis route. The high purity of LSCO cathode powder as confirmed by X-ray diffraction (XRD) analysis was prepared to become cathode slurries using different electrode binders namely polyvinyl alcohol (PVA), polyvinyl butyral-co-vinyl alcohol-co-vinyl acetate (PVB), polyvinyl pyrrolidone (PVP), ethyl cellulose (EC) and ethylene glycol (EG). These slurries were separately painted on the pellet surfaces of BaCe0.54Zr0.36Y0.1O2.95 (BCZY) solid electrolyte to fabricate symmetrical cell of LSCO/BCZY/LSCO. The role of electrode binder on contact formation between LSCO and BCZY was investigated. The contact formation at LSCO/BCZY interface was examined by Scanning Electron Microscope equipped with Electron Dispersive Spectroscopy (SEM/EDS). Three distinct areas corresponding to the LSCO cathode, BCZY electrolyte and LSCO/BCZY interface with free or crack/hole was observed in the SEM micrographs. The elemental compositions at these three areas were confirmed by EDS and their percentage was presented. The cells prepared with the aid of EC, EG, PVA and PVB showed poor contact between LSCO and BCZY due to the presence of the crack and/or hole (air gap) at interface except for the cell prepared with PVP. Therefore, PVP plays an important role in making a good contact between LSCO cathode and BCZY electrolyte. Keywords: La0.6Sr0.4CoO3-? cathode, BaCe0.54Zr0.36Y0.1O2.95 electrolyte, electrode binder, SEM/ED

Characterization of La0.6Sr0.4CoO3-α cathode powder prepared by a combined citrate-EDTA method / Abdullah Abdul Samat, Mohd Azlan Mohd Ishak and Nafisah Osman

The La0.6Sr0.4CoO3-α (LSCO) cathode powder was prepared by a combined citrate-EDTA method using nitrate based chemicals. Citric (CA) and ethylenediaminetetraacetic acid (EDTA) were used as chelating agents and ethylene glycol (EG) as a polymerizing agent. The formation of metal complexes of LSCO was analyzed using Fourier transform infrared (FTIR) spectroscopy. Various organic compounds such as carbonyl and carbonate groups were observed in FTIR spectra. The as-synthesized LSCO powder analyzed by thermogravimetric analysis (TGA) showed there were three stages of weight losses with a drastic weight loss observed between 150-550 ºC. A complete decomposition of intermediate compounds was observed at 800 ºC indicating the formation of metal oxide was formed. This result was further confirmed by X-ray diffraction (XRD) analysis which revealed the calcined LSCO powders at 800 ºC and 900 C formed a single perovskite phase. LSCO cathode slurry was prepared by adding polyvinyl pyrrolidone (PVP) as binder. This slurry was painted on pellet surfaces of BaCe0.54Zr0.36Y0.1O2.95 (BCZY) electrolyte. Scanning electron microscopy (SEM) results showed the LSCO cathode was well adhered on BCZY electrolyte. It is apparent that the binder plays an important role in making a good contact between the obtained high purity LSCO cathode and BCZY electrolyte

18F-FDG-PET CT features of colo-colic intussusceptions in patient with colonic carcinoma

Colo-colic intussusception is a rare manifestation of a primary tumour in an adult patient. This article aims to document the rarity of colo-colic intussusception features on the 18 FDG-PET-CT in a patient with primary colonic carcinoma. An 18 FDG-PET-CT was performed for the purpose of pretreatment staging of a colonic carcinoma in a 61-year-old man following a diagnostic colosnoscopic biopsy. He presented with abdominal distension and peri-rectal bleeding for a month. The fused 18 F-FDG PET-CT image revealed an FDG-avid mass in the left hemicolon showing a rim of FDG avidity denoting the head of intussusceptum. There are also multiple FDG-avid nodules seen along the anti-mesenteric colonic fat suspicious for lymph nodes metastasis. Debulking of tumour revealed a mucinous adenocarcinoma of colon with a metastatic lymph node. 18 FDG PET-CT features of intussusception in colonic carcinoma have never been described before. It can potentially become a preferred diagnostic tool in delineating a potential tumour mass within the intussusceptions that help improve prognosis in patients with malignancy

Online literature circles in learning Hamlet among pre-service teachers

Literature instruction may serve multiple functions. This case study aimed at investigating the perceptions on the use of online literature circles among 62 first year Teaching English as a Second Language pre-service teachers in a literature course at Universiti Teknologi Malaysia. The participants were assigned to read and participate in online literature circles about the play Hamlet by William Shakespeare. Based on cooperative learning, the participants rotated in playing the roles of the Discussion Director, Device Detective, Imaginative Illustrator, Creative Connector, and Passage Picker in each group. Data from a survey were analyzed in descriptive statistics, while data from the role sheets based on the five roles and the online video of 3 literature circle discussions were analyzed thematically. The findings are significant for teacher training institutions and in-service teachers. This study was able to show that online literature circles were perceived as interesting, engaging, challenging, and fun. The participants engaged in different learning processes involving cognitive, affective, and language skills. Though this study identified some challenges, online literature circles have many benefits and are recommended for literature instruction for pre-service teacher training

Pengaruh agen kimia berbeza terhadap penguraian terma dan pembentukan fasa bahan La0.6Sr0.4CoO3- δ yang disediakan melalui kaedah Sol-Gel

Sifat penguraian terma dan pembentukan fasa bahan lantanum strontium kobalt oksida, La0.6Sr0.4CoO3-δ (LSC) yang disediakan melalui kaedah sol-gel berbantu agen kimia berbeza, iaitu agen serakan, agen pempolimeran dan agen permukaan aktif atau surfaktan telah dicirikan secara sistematik masing-masing melalui analisis termogravimetrik (TG) dan pembelauan sinar-X (XRD). Penguraian terma bahan organik dan bahan bukan organik yang tidak diperlukan dalam serbuk pelopor bahan LSC telah lengkap pada suhu kurang daripada 1000 °C bagi serbuk pelopor yang disediakan dengan menggunakan agen serakan dan agen pempolimeran, dan suhu melebihi 1000 °C bagi serbuk pelopor yang disediakan dengan menggunakan surfaktan. Sifat penguraian terma ini dipengaruhi oleh suhu pengeringan serbuk pelopor tersebut dan berat molekul agen kimia. Pembentukan fasa tunggal perovskit LSC telah disahkan dalam serbuk pelopor yang disediakan dengan menggunakan agen serakan, iaitu karbon teraktif dan agen pempolimeran, iaitu etilena glikol selepas serbuk pelopor tersebut dikalsin pada suhu 900 °C. Sebaliknya, fasa tunggal perovskit LSC tidak terbentuk secara lengkap dalam serbuk pelopor yang disediakan dengan menggunakan surfaktan (polietilena glikol, Triton-X-100, Brij-97 dan Tween-80) walaupun selepas serbuk pelopor tersebut telah dikalsin pada suhu yang lebih tinggi iaitu 1100 °C. Kepekatan surfaktan, nisbah molar surfaktan kepada logam kation dan nilai pH larutan bahan pelopor yang tidak sesuai telah menyumbang kepada keputusan tersebut

Association between Hs-CRP and other cardiovascular risk factors with blood pressure in young adults

INTRODUCTION: Hypertension remains the leading preventable risk factor for premature mortality and morbidity worldwide. The use of high-sensitivity C-reactive protein (hs-CRP) as the global risk prediction assessment for cardiovascular diseases (CVD) in asymptomatic individuals suggests the possibility that higher hs-CRP, or subclinical inflammation, maybe one of the causal factors contributing to an increased risk of CVD in young hypertensive patients. Most studies of hypertension and hs-CRP association were conducted regionally, whereby most of the participants were Caucasians with age beyond 40 years old. Studies of this association among young adults in Asian populations are lacking, therefore, a generalization of data might be limited to certain ages and populations only. MATERIALS AND METHOD: This comparative cross-sectional study analysed the association between hs-CRP and other cardiovascular risk factors with three different blood pressure statuses categorised into Normotensive (NT), Pre-hypertensive (PHT), and Hypertensive (HPT) groups among young adults in Kuantan, Pahang, Malaysia. RESULTS: Independently, the association was significant only in males and subjects with parental history of hypertension in the prehypertensive group. However, in the hypertensive group, the relationships were significant not only in males and individuals with parental histories of hypertension but also in obese subjects. Hs[1]CRP was not associated with blood pressure status in the present study. CONCLUSION: The hypothesis that hs[1]CRP has an independent association with blood pressure status was not demonstrated in the present study. However, the observed association between circulating hs-CRP and blood pressure status is likely to be driven by confounders namely age, gender, genetic factors, and BMI status

The potential of standardized quassinoid-rich extract of Eurycoma longifolia in the regulation of the oestrous cycle of rats

Objective: To evaluate the effects of Eurycoma longifolia (E. longifolia) standardized extract on the oestrous cycle, levels of reproductive hormones and histology of the ovaries of Sprague-Dawley rats. Methods: Female rats were orally treated with E. longifolia standardized extract at the dose levels of 2.5, 5.0, 10.0, 25.0, 50.0 and 100.0 mg/kg of body weight over 5 days. Vaginal smears were monitored daily within the duration and after withdrawal of the treatment before being sacrificed. The body weights of the females were recorded before and after the 5 days treatment. At the end of the experiments, blood samples were collected for determination of testosterone, oestradiol and progesterone levels. Ovaries were removed, weighed and examined for histomorphological changes. Results: The administration of E. longifolia standardized extract did not significantly alter the oestrous cycle of the rats during the 5 days treatment and after withdrawal of the treatments. This was supported by normal testosterone, oestradiol and progesterone levels as well as normal morphology of the ovaries. Conclusions: The data obtained showed that E. longifolia standardized extract did not exhibit any toxic effect on reproductive activities of female rats suggesting potential use in the management of infertility

Molecular phylogenetic inference of White-Spotted Guitarfish (Rhynchobatus australiae) collected from local Malaysian fish markets

The white-spotted guitarfish (Rhynchobatus australiae) is in high demand at local Malaysian fish markets because its fins are a valuable food source. To date, few molecular studies have characterized their genetic identity. We have conducted a molecular study to infer the phylogenetic relationships of white-spotted guitarfish, which portray a similar morphology to sharks and rays. The main objective of this study was to determine the phylogenetic position of R. australiae using cytochrome oxidase I (COI) sequences of mitochondrial DNA based on fish samples collected from local Malaysian fish markets. This study included nine genetic samples of R. australiae and fourteen samples from other members of the shark and ray families, including Sphyrna lewini (Sphyrnidae), Rhizoprionodon oligolinx and Carcharhinus sorrah (Carcharhinidae), Dasyatis zugei, Himantura walga, Himantura gerradi, Himantura jenkinsii and Neotrygon kuhlii (Dasyatidae). Chimaera fulva, a member of the Chimaera family, was used as the outgroup. Sequences in size of ~701 base pairs were successfully obtained from all fish samples. The phylogenetic tree topology was reconstructed using distance-based (neighbor-joining) and character-based (maximum parsimony) methods using MEGA and PAUP software. Results indicated that R. australiae formed monophyletic clade and is closely related to sharks (Sphyrnidae and Carcharhinidae). This conclusion was also supported by genetic distance analysis which indicated that Rhynchobatidae and sharks (Carcharhinidae and Sphyrnidae) were closer to each other than to rays (Dasyatidae). This study has proven the efficiency of the COI mitochondrial locus in revealing the phylogenetic position of R. australiae. Research findings from this study have increased our understanding of the phylogenetic relationships among guitarfish, sharks, and rays, and their respective taxonomic positions are given their shared morphological characters. This will benefit us in identifying these fish species before consumption from local fish markets

The concept of Wasatiyyah in governing the Muslim community of Singapore

Wasatiyyah is the original nature of Islam, therefore Allah calls Muslims as ummatan wasatan. The principle of wasatiyyah is the reason why Islamic sharia can be relevant to be practiced anywhere and at all times, including in secular countries such as Singapore. This article discusses the concept of wasatiyyah implemented by MUIS and related institutions in governing the Muslim community in Singapore. The research method in this article is qualitative with a literature review approach. The collected data was analyzed using the opinion of scholars or experts in the field of sharia law. From the results of this study, the author concludes that in governing the Muslim community of Singapore, MUIS and related institutions have adopted the concept of wasatiyyah