12 research outputs found
Supraclinoid direct carotid-cavernous sinus fistula
Carotid-cavernous fistulas (CCFs) are vascular shunts between the carotid arterial system with direct drainage into the cerebral venous system, mainly to the cavernous sinus. Direct CCF is a well-recognised complication following head trauma. Classically in direct or traumatic CCF, vessel wall tear occurs at the cavernous segment of the internal carotid artery, between the fixed and free segment. Tears at the supraclinoid segment are rare. We report a case of an internal carotid artery supraclinoid segment pseudoaneurysm, with a direct communication with the cavernous sinus, draining into the superior ophthalmic vein
Kesan ketebalan filem terhadap fotoelektrokimia titania dioksida (TiO2) yang disediakan melalui kaedah pemendapan bantuan aerosol wap kimia (AACVD)
Titanium oksida (TiO2) merupakan semikonduktor yang mempunyai jurang jalur yang besar dengan ciri-ciri foto penukaran
dalam spektra UV sesuai digunakan dalam pelbagai aplikasi. Dalam penyelidikan ini, kaedah pemendapan bantuan aerosol
wap kimia (AACVD) digunakan bagi menghasilkan lapisan filem TiO2 dengan ketebalan yang berbeza berdasarkan tempoh
pemendapan yang dikenakan (3, 5 dan 7 min). Lapisan filem dimendapkan pada suhu 450oC. Melalui kedah AACVD, lapisan
TiO2 yang dimendapkan di atas kaca FTO (florin dop tin oksida) akan menjadi lebih nipis dan struktur lapisan menjadi lebih
padat.Titanium diisopropoxide bis(acetylacetonate) dan etanol digunakan untuk menghasilkan pelopor AACVD. Ciri morfologi
dan ketebalan filem nipis TiO2 diuji menggunakan mikroskopi daya atom (AFM) yang menunjukkan permukaan berliang
pada filem nipis tersebut. Ciri optik filem nipis TiO2 diuji menggunakan spektra pancaran ultra-lembayung cahaya nampak
(UV-Vis) dan keputusan menunjukkan filem nipis memberikan ketelusan yang tinggi pada kawasan kelihatan berdasarkan
jurang jalur yang diperolehi. Prestasi filem nipis dicirikan menggunakan voltammetri sapuan linear (LSV) dan spektroskopi
impedans elektrokimia (EIS). TiO2-5 min memperoleh purata ketebalan 61 nm melihatkan prestasi J-V terbaik iaitu 6.30 x
10-4 A/cm-2 dan memberikan rintangan cas yang terendah. Tambahan, pemendapan filem menunjukkan kelekatan yang baik
pada substrat, kebolehkeluaran semula dan permukaan filem nipis yang sekata. Berdasarkan keputusan yang diperolehi, TiO2
yang disediakan menggunakan kaedah AACVD sangat sesuai digunakan dalam pelbagai aplikasi seperti sel suria generasi
ketiga yang memerlukan filem nipis dengan ketebalan yang rendah, berliang, ketelusan yang tinggi, fotoaktif, dan stabil
Peningkatan kecekapan pemisahan air menggunakan g-C3N4 yang disinar gama
Dalam kajian ini, kesan sinar gama ke atas bahan semikonduktor g-C3N4 kGy (0.1 kGy dan 0.5) dibincangkan dan dibandingkan dengan sampel yang tidak disinar untuk melihat perbezaanya. Bahan g-C3N4 disintesis dari urea melalui proses pempolimeran haba pada suhu 520°C. Struktur dan morfologi g-C3N4 dianalisis dengan menggunakan pembelauan Sinar- X (XRD), spektroskopi transformasi Fourier inframerah (FT-IR), mikroskop pengimbas elektron pancaran medan dengan spektroskopi tenaga sinar-X (FESEM-EDX), spektroskopi cahaya nampak - ultraungu (UV-Vis) dan ketumpatan arus (LSV). Sinar gama telah mengubah struktur ikatan g-C3N4 dan mengurangkan sela jalur iaitu daripada 2.80 eV kepada 2.72 eV. Di samping itu, sampel g-C3N4 yang disinar pada 0.1 kGy menghasilkan prestasi lima kali ganda lebih tinggi iaitu daripada 3.59 μAcm-2 kepada 14.2 μAcm-2 pada 1.23 V lawan Ag/AgCl dalam larutan elektrolit 0.5 M Na2SO4 (pH7). Kesimpulannya, keputusan kajian menunjukkan bahan semikonduktor yang dirawat dengan sinar gama berpotensi untuk meningkatkan fotoelektrokimia (PEC) pemisahan air
Blended Wing-Body Unmanned Aerial Transport Aircraft: A conceptual design
UAVs have advantages in assisting works such as aerial surveillance, agriculture and transport with minimal risk, low operating costs, relatively inexpensive price and ability to automate the work. Currently the UAV technology is expanding to include unconventional designs and configurations to suit to their purposes. Blended Wing-Body (BWB) technology promises high aerodynamic efficiency that translates to better flight performance over conventional fixed wing, multirotor and helicopter-type UAVs. Previous research has characterized flight behavior of a Blended Wing-Body UAV stabilized by four elevons. The study leads to optimization of BWB UAV design that ensured positive stability and good controllability. While many courier companies are focusing on the short-range, last-mile delivery using multirotor drones, the transportation of parcels between cities is still by land vehicles susceptible to traffic congestion, floods and other natural disasters. Fixed-wing UAV is preferred for such transportation in Africa and no such service is offered in Malaysia. The popular multirotor transport drone proposed by courier companies in Malaysia is limited to short range delivery within a city. This paper introduces a conceptual design of a parcel transport UAV called Baseline-X BWB that carries two kilograms of payload for inter-city transport. The conceptual design scope of discussion is limited to aerodynamic estimation, flight performance and monetary cost. The advantages of this prototype over other UAVs are its longer range per battery capacity, larger and heavier payload capacity, and lower operating cost per mile and fleet cost per route than conventional design of the same size making it feasible and profitable for operators.
Keywords: Air Transport; Blended Wing-Body; Unmanned Aerial Vehicle
eISSN: 2398-4287© 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.
DO
Performance-Enhancing Sulfur-Doped TiO<sub>2</sub> Photoanodes for Perovskite Solar Cells
High-performance electron transport layer (ETL) anode generally needs to form a uniform dense layer with suitable conduction band position and good electron transport properties. The TiO2 photoanode is primarily applied as the ETL because it is low-cost, has diverse thin-film preparation methods and has good chemical stability. However, pure TiO2 is not an ideal ETL because it lacks several important criteria, such as low conductivity and conduction band mismatch with compositional-tailored perovskite. Thus, TiO2 is an inefficient photo-anode or ETL for high-performance perovskite devices. In this study, sulfur as dopant in the TiO2 photo-anode thin film is used to fabricate solid-state planar perovskite solar cells in relatively high humidity (40–50%). The deposited S-doped thin film improves the power conversion efficiency (PCE) of the device to 6.0%, with the un-doped TiO2 producing a PCE of 5.1% in the best device. Improvement in PCE is due to lower recombination and higher photocurrent density, resulting in 18% increase in PCE (5.1–6.0%)
Rapid fabrication of efficient P-type perovskite-sensitized solar cells using hot-air drying method
© 2020 The successful development of organic-inorganic perovskite materials mainly based on CH3NH3PbI3 has improved the PCE of solar cells significantly and reduced the fabrication cost relatively. The majority of the researches focused on studying different ways of improving the performance and stability of perovskite devices with less attention paid to minimizing the time of fabrication. The reduction of fabrication time can simultaneously reduce the fabrication cost and boost the industrial manufacturing capability. In this work, we report a simple and rapid method of making CH3NH3PbI3 layer at ambient laboratory conditions and applying it for advancing the photon-to-electricity conversion efficiency of liquid-state CuO-based perovskite-sensitized solar cells. The whole fabrication process starting from electrodepositing CuO to sandwiching counter electrode entails less than 10 min and the device efficiency reaches up to 0.35% under one sun illumination