Effect of gap lenghts of sphere-sphere electrodes on air breakdown level under lightning impulse

Impinging jets are a best method of achieving particularly high heat transfer coefficient and are therefore employed in many engineering applications. In this study we seek to understand the mechanism of the distributed heat on the curve surface with the goal of identifying preferred methods to predicting jet performance. The goals that have been achieved in the numerical results displayed are determine the influence of impingement jet characteristics on thermal and flow field on a curve surface, determine the variation of Nusselt numbers (NuD) along the curve surface in order to understand the heat transfer characteristics and study the effect of position (in the center, in the mid and in the end) and angle (α=90°, 60° and 30°) of jet impingement on curve surface, different Reynolds numbers (ReD) in range of (5000, 6000, 7000, 8000 and 9000). The program, which was extracted results it is (GAMBIT 2.4.6) and (FLUENT 6.3), simulation is (2-D) in submerged jet flow and the continuity, momentum and energy equations were solved by means of a finite volume method (FVM). This study covers the effect of different Reynolds numbers (ReD) on average Nusselt numbers (Nuavg) and local Nusselt numbers (NuD). From the result, the average Nusselt numbers (Nuavg) increased with the increase of Reynolds numbers (ReD) for all cases, in comparison between different positions (center, mid and end), of nozzle on curve surface at angle (α=90°) the maximum value of average Nusselt numbers (Nuavg=388.3) is found when the nozzle locate in the end followed by the mid position and smallest value of average Nusselt numbers (Nuavg=182.25) in the center of curve surface. In case of slant angle (α=60º) the maximum value of average Nusselt numbers (Nuavg=387.47) is found when the nozzle locate in the end followed by the mid position and smallest value of average Nusselt numbers (Nuavg=308.3) in the center of curve surface

Hematological, biochemical, and histopathological evaluation of the Morus alba L. leaf extract from Brunei Darussalam: acute toxicity study in ICR mice

Background: Studies have reported that the phytochemical content of Mulberry (Morus alba Linn.) is influenced by the area where it grows. On the other hand, the study of the bioactivity and toxicity of mulberry leaves from Brunei Darussalam still needs to be completed. In particular, the investigation regarding the safe dose for Mulberry’s application from Brunei Darussalam has yet to be studied. Hence, toxicity information must be considered even though the community has used it for generations. Aim: This study investigated Morus alba ethanolic leaf extract (MAE) to observe the acute toxicity in mice. Methods: In particular, this study utilized 12 female Institute of Cancer Research mice, 8 weeks old, divided into 2 groups: the control group and the MAE group (2,000 mg/kg single dose). Physiology, hematology, biochemistry, and histology were analyzed during the study. Results: The examination result indicated no mortality and behavioral changes throughout the testing period. However, the mice developed mild anemia and leukopenia, followed by decreased numbers of neutrophils, lymphocytes, and monocytes. In addition, the mice developed a mild hepatocellular injury, indicated by significant (p 0.05). Conclusion: It was evident that a single oral administration of MAE was not lethal for mice (LD50, which was higher than 2,000 mg/kg). However, the administration of high doses of MAE must be carefully considered

Growth kinetic and composition of the interfacial layer for RF sputtering Al2O3 layer on germanium

Purpose – The quality of GeOx–Ge interface and the equivalent oxide thickness (EOT) are the main issues in fabricating high-k/Ge gate stack due to the low-k of GeOx interfacial layer (IL). Therefore, a precise study of the formation of GeOx IL and its contribution to EOT is of utmost importance. In this study, the GeOx ILs were formed through post-oxidation annealing of sputtered Al2O3 on the Ge substrate. The purpose of this paper is to report on growth kinetics and composition of IL between Al2O3 and Ge for HCl- and HF-last Ge surface. Design/methodology/approach – After wet chemical cleaning with HCl or HF, Al2O3 was grown onto the Ge surface by RF sputtering. Thickness and composition of IL formed after post-anneal deposition at 400°C in dry oxygen ambience were evaluated as a function of deposition time by FESEM and characterized by X-ray photoelectron spectroscopy, respectively. Findings – It was observed that the composition and thickness of IL were dependent on the starting surface and an aluminum germinate-like composition was formed during RF sputtering for both HF- and HCl-last starting surface. Originality/value – The novelty of this work is to investigate the starting surface of Ge to IL growth between Al2O3/Ge that will lead to the improvement in Ge metal insulator field effect transistors (MISFETs) applicatio

Kaedah diagnostik semasa dan penggunaan ujian Titik Penjagaan Pantas (POC) bagi mendiagnos Hiperkolesterolemia Famili (FH)

Hiperkolesterolemia Famili (FH) ialah penyakit genetik yang diwarisi secara autosomal dominan dan dicirikan melalui peningkatan kepekatan plasma kolesterol lipoprotein berketumpatan rendah (LDL-C) di dalam darah. Pesakit FH yang tidak didiagnosis di peringkat awal dan tidak dirawat boleh meningkatkan risiko penyakit jantung koronari pramatang. Dengan kepesatan teknologi dalam bidang biologi molekul, terdapat pelbagai strategi telah diambil untuk membolehkan diagnosis awal FH dilakukan. Teknik-teknik ini dapat meningkatkan keberkesanan kos dan tempoh masa pengesanan adalah lebih cepat. Kaedah diagnostik semasa yang sedia ada untuk mendiagnosis FH yang melibatkan kriteria skor berasaskan algoritma dan pelbagai kaedah diagnosis molekul seperti kaedah penjujukan generasi kedua (NGS), penjujukan Sanger, multiplex ligation-dependent probe amplification (MLPA) dan mikroatur melalui hibridisasi DNA akan dibincangkan di dalam ulasan ini. Walau bagaimanapun, ujian genetik molekul ini tidak tersedia secara meluas atas sebab seperti prosedur yang memakan masa, kos yang tinggi dan keperluan kepada kakitangan terlatih. Oleh itu, ulasan ini memberi penekanan kepada penggunaan ujian titik penjagaan pantas (point of care, POC) sebagai pendekatan untuk mendiagnosis FH kerana ketiadaan ujian genetik bagi pemeriksaan rutin di negara yang kekurangan infrastruktur dan kepakaran. Ujian aliran lateral (LFA) telah mendapat perhatian sebagai kaedah diagnostik POC kerana ianya mudah, memerlukan kos yang rendah dan proses yang lebih cepat. Kelebihan ini menjadikan LFA sebagai teknik yang berpotensi dalam menangani beberapa cabaran bagi diagnosis FH khususnya bagi diagnosis awal terhadap keluarga pesakit

Kajian kes mengenai penggunaan perisian sosial di perpustakaan IPTA dan IPTS di Malaysia

Web 2.0 is an application and social networking software that provides interactive information sharing, user oriented design and collaboration on the Internet. Some popular social software that are being used are Facebook Twitter, Blog dan Flickr. This article is the results of a study which seeks to identify the usage of Web 2.0 applications in 20 public and 14 private academic libraries throughout Malaysia. A virtual survey was conducted from October 2009 to February 2010. The findings show that Web 2.0 applications are being used in some academic libraries. Currently, the Blog is the most widehly used application

Computer aided learning in the community follow up module: a pilot study

The need to deliver teaching material to undergraduates using the is compelling in view of the many advantages that the Internet provides. Report on the use of Computer Aided Learning (CAL) in teaching various major disciplines in medicine among. In view of this, the Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia, embarked on a pilot study on the use of CAL for teaching of Year Four medical students undertaking the Community Follow-up Project (CFUP) to test the viability of CAL as a teaching method. Objectives: This paper describes our experience in the design and deployment of CAL as a complement to the traditional teaching methods of CFUP. We also present the findings of a survey on students’ opinion of the use of CAL in the CFUP. Methods: A website containing lecture notes and a discussion forum was set up to provide the CAL component. Students were asked to access the websites, download lecture notes and participate in a tutorial in the form of the discussion forum. A survey was conducted at the end of the CFUP to gauge students’ experience of computer use and their reaction to survey indicated that students were able to use the CFUP website and gained from the teaching material posted online. Discussion: A high percentage of our students possessed their own computers and all participants had access to the Internet. Students were able to access the website and participate in the discussion forum. Conclusion: The results demonstrate that it is viable to use CAL as teaching methods in the CFUP

Sputtered Encapsulation as Wafer Level Packaging for Isolatable MEMS Devices: A Technique Demonstrated on a Capacitive Accelerometer

sensor

Dielectrophoresis Manipulation: Versatile Lateral and Vertical Mechanisms

Discussing the topic of the capability of dielectrophoresis (DEP) devices in terms of the selective detection and rapid manipulation of particles based on the DEP force (FDEP) via contactless methods is challenging in medical research, drug discovery and delivery. Nonetheless, the process of the selective detection and rapid manipulation of particles via contactless DEP based on dielectric particles and the surrounding medium can reduce the effects of major issues, including physical contact with the particles and medium contamination to overcome operational difficulties. In this review, DEP microelectromechanical system (MEMS) microelectrodes with a tapered profile for the selective detection and rapid manipulation of particles were studied and compared with those of conventional designs with a straight-cut profile. The main objective of this manuscript is to review the versatile mechanism of tapered DEP MEMS microelectrodes for the purpose of selective detection and rapid manipulation. Thus, this review provides a versatile filtration mechanism with the potential for a glomerular-based membrane in an artificial kidneys’ development solution for implementing engineered particles and cells by lateral attraction as well as vertical repulsion in the development of lab-on-a-chip applications. For tapered DEP MEMS microelectrodes, the scope of this study methodology involved the characterisation of DEP, modelling of the polarisation factor and the dynamic dielectric changes between the particles and medium. Comprehensive discussions are presented on the capability of tapered DEP microelectrodes to drive the selected particles and the simulation, fabrication and testing of the tapered profile. This study revealed an outstanding performance with the capability of producing two regions of high electric field intensity at the bottom and top edges of the side wall of tapered microelectrodes. Observations on particle separation mainly by the lateral attraction force of particles with positive DEP on the y-axis and vertical repulsion force of particles with negative DEP on the z-axis proved an efficient and uniform FDEP produced by tapered electrodes. In conclusion, this study confirmed the reliability and efficiency of the tapered DEP microelectrodes in the process of selective detection and rapid manipulation at a higher efficiency rate than straight-cut microelectrodes, which is significant in DEP technology applications

Therapeutic effect of Morus alba leaf extract and chlorogenic acid on inhibiting the progression of kidney disease

It is well-established that Morus alba and its derivatives have been clinically proven to have antioxidant and anti-inflammatory properties. Although several studies have mentioned the beneficial effect of Morus alba on kidney disorders, the role of Morus alba in CKD still needs to be explored. Thus, this study investigated the effect of Morus alba and chlorogenic acid treatment on renal fibrosis in mice induced with unilateral urethral obstruction (UUO). Twenty-five Balb/c mice were randomly divided into five groups: the sham-operated group, the UUO untreated group, and the UUO treated with enalapril (ENA), Morus alba leaves extract (MLE) and chlorogenic acid (CGA) groups. Urine, blood, and organ samples were collected to evaluate urinalysis, haematology, biochemistry, and histopathology. The result indicated that the UUO group had significantly higher levels of creatinine (p < 0.001) and urea (p < 0.05), as well as hydronephrosis and urine crystal sedimentation (p < 0.05). In comparison to the UUO group, the MLE and CGA groups displayed improved urine profiles, ameliorated anaemia (p < 0.05), and urine crystals (p < 0.05). The administration of CGA also significantly reduced serum creatinine (p < 0.05) and protein-creatinine ratio (UPCr) levels. In addition, MLE and CGA could prevent hydronephrosis and delay renal damage, particularly in the dilation of Bowman’s space, tubular injury, loss of tubular epithelium, and cellular inflammation. In conclusion, Morus alba and CGA had a therapeutic effect in minimising the progression of renal damage. As a result, it can be promoted as a complementary renoprotective product based on natural products, as it has a potentially similar effect to enalapril

Lab-on-a-chip Dielectrophoretic Manipulation of Beta-2 microglobulin for Toxin Removal in An Artificial Kidney

Background: This paper presents a fundamental study of protein manipulation under the influence of dielectrophoretic (DEP) force for a lab-on-a-chip platform. Objective: Protein manipulation is dependent on the polarisation factor of protein when exposed to an electric field. Therefore the objective of this work is a microfluidic device and measurement system are used to characterise the human beta-2 microglobulin (β2M) protein via lateral attractive forces and vertical repulsive forces by means of DEP responses. Method: The manipulation of the β2M protein was conducted using a microfluidic platform with a tapered DEP microelectrode and the protein concentration was quantified based on a biochemical interaction using an Enzyme-Linked Immunosolvent Assay (ELISA). The protein distribution has been analysed based on the β2M concentration for each microfluidic outlet. Results: At 300 kHz, the protein experienced a negative DEP (nDEP) with of 83.3% protein distribution on the middle microchannel. In contrast, the protein experienced a positive DEP (pDEP) at 1.2 MHz with of 78.7% of protein on the left and right sides of the microchannel. Conclusion: This is concept proved that the tapered DEP microelectrode is capable of manipulating a β2M via particle polarisation, hence making it suitable to be utilised for purifying proteins in biomedical application