Design of a 3D Printed UWB Antenna for a Low-Cost Wireless Heart and Respiration Rate Monitoring

This paper introduces an ultra-wideband (UWB) horn antenna for a low-cost wireless heart and respiration rate monitoring that is manufactured by a 3D printing technology. The proposed design operates within 3.1-10.6 GHz. The horn antenna is designed within the 15-dB gain which is sufficient to be used in medical system. The horn was designed to calculate the gain in MATLAB using an approximation method and simulated using CST Microwave Studio. The proposed antenna is 4-6 GHz (G-Band) operating. A printed antenna which is supported by WR-187 rectangular waveguide is fabricated using low cost polylactic acid (PLA). The surface is then metalized using copper tape on the inside. The simulation result of reflection coefficient for different conductivity and thickness of coating metal is compared, the developed 3D printed antenna successfully operated within given frequency range of 3-11 GHz which covered the ultra-wideband frequency range

Physicochemical and biochemical properties of pepsin-solubilized collagen isolated from the integument of Sea Cucumber (Stichopus vastus)

The integument (high collagen content) of sea cucumber Stichopus vastus is generally wasted after harvesting, whereas only its stomach and intestines are eaten in few Asian countries. Amino acid composition, thermal transition temperature (Tm), zeta potential, solubility, moisture absorption and retention capacities, proximate composition and morphology of pepsin-solubilized collagen (PSC) isolated from the integument of S. vastus were studied. Amino acid composition revealed that glycine was dominant in the isolated collagen. PSC was found to have an isoelectric pH of 4.67, good moisture absorption and retention capacity at higher humidity, a sharp effect of pH and NaCl concentration on solubility, and an inverse relationship between temperature and viscosity. PSC also showed the maximum Tm to be 37.3C, very high protein content and ultrastructural characteristics. Hence, the PSC has the potential to be used as a functional ingredient in food, cosmetics and nutraceutical products

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

Recent Developments for the Application of 3D Structured Material Nickel Foam and Graphene Foam in Direct Liquid Fuel Cells and Electrolyzers

Platinum and platinum-based catalysts are some of the most effective catalysts used in fuel cells. However, electrocatalysts used for direct liquid fuel cells (DLFCs) and electrolyzers are high cost and suffer from several other problems, thus hindering their commercialization as power sources to produce clean energy. Common issues in electrocatalysts are low stability and durability, slow kinetics, catalyst poisoning, high catalyst loading, high cost of the catalytic materials, poisoning of the electrocatalysts, and formation of intermediate products during electrochemical reactions. The use of catalyst supports can enhance the catalytic activity and stability of the power sources. Thus, nickel foam and graphene foam with 3D structures have advantages over other catalyst supports. This paper presents the application of nickel foam and graphene foam as catalyst supports that enhance the activities, selectivity, efficiency, specific surface area, and exposure of the active sites of DLFCs. Selected recent studies on the use of foam in electrolyzers are also presented

Effect of 132kV cross-country fault on distance protection system

Towers with different voltage levels are now widely used transmission system. On this situation, it is probably that the faults that occurred will involve the two different voltage levels at the same time in a same tower. This paper presents the study of the effect of cross-country fault on distance protection. This study has been performed on a simple model circuit in transmission line. The cross-country fault analysis is more complicated than basic fault because it has to be considered fault locations simultaneously in the analysis. PSCAD/EMTDC software is used to perform the modeling and analysis of the effect of cross-country fault on distance protection. From simulation result, it can be identified the effect of cross-country fault on distance protection and the result can be compared with the basic fault analysis

CO-COMBUSTION OF REFUSE DERIVED FUEL WITH COAL IN A FLUIDISED BED COMBUSTOR

Power generation from biomass is an attractive technology which utilizes municipal solid waste-based refused derived fuel. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from refuse derived fuel was co-fired with coal in a 0.15 m diameter and 2.3 m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those from pure coal combustion. This study proved that the blending effect had increased the carbon combustion efficiency up to 12% as compared to single MSW-based RDF. Carbon monoxide levels fluctuated between 200-1600 ppm were observed when coal is added. It is evident from this research that efficient co-firing of biomass with coal can be achieved with minimum modification of existing coal-fired boilers

N-doped CNT: distribution electron on different ratio N/C for oxygen reduction reaction

Carbon nanotubes (CNTs) have the advantage to improve electrochemical fuel cell reactions by increasing the dispersion of nanoparticles as well as having high strength in mechanical and electrical properties. Therefore, this study presents the comparison of nitrogen doped CNT and other doping heteroatom on CNT as a catalyst support for application in the Direct Liquid Fuel Cell (DLFC). The doping ratio in CNT was conducted to determine the effect of the oxygen reduction reaction. In addition, the effect of CNT diameter in oxygen adsorption also has been tested. The models and calculations were done using density functional theory (DFT). The result showed that the ratio of N/C is decreases as the diameter of CNT decreases. The value is even dropped as the unit cell is increased to 1x1x2. The band gap value of CNT before doping is higher compared to after nitrogen doping. While increasing the diameter of doped CNT has increased the mulliken charge distribution and thus make the model more stable. In the adsorption energy of molecule oxygen, the 1x1x2 unit cell of CNT and large diameter show a remarkable and stable compared to in 1x1x1 unit cell and small diameter of CNT. Thus, the adsorption energy of the oxygen molecule shows a more stable value in the low doping ratio and high CNT diameter compared to a high doping ratio and a small diameter of the CNT. This result shows the potential of the CNT in helping to improve electrochemical reaction in DLFC

Effects of heat-moisture and alkali treatment on the enzymatic hydrolysis of porous sago (Metroxylon sagu) starch

Pretreatment(s) of heat-moisture treatment (HMT) and alkali treatment was tested for the enzymatic hydrolysis of sago (Metroxylon sagu) starch. HMT was undergone by autoclaving the sago starch at 120°C for 60 min. While sodium hydroxide pellets (0.60% [w/w starch dry basis (d.b.)] to 50 g of sago starch) were applied as the alkali treatment. Dual pretreatments were also evaluated. The dextrose equivalent values of porous starch with alkali pretreatment (31%), HMT (37%), and dual pretreatments (42%) were significantly higher than those of non-pretreated porous sago starch (21%). Greater porosity of pretreated starch granules (0.91–5.19 µm) was also obtained. The thermal properties (gelatinization temperature) of porous starch with pretreatments were improved compared to the non-pretreated porous sago starch. In addition, the pretreatment(s) also improved the oil adsorption capacity of the porous starch. Dual pretreatments were an efficient way to facilitate enzymatic hydrolysis in preparing porous sago starch

Carbon dioxide adsorption on sawdust biochar

Biochar has been acknowledged for its unique property which makes it potential candidates as adsorbent for carbon dioxide (CO2) in the flue gas system. In this study, the properties of raw sawdust biochar (SB) and amine treated sawdust biochar (NSB) are being compared. Ultimate analysis was performed using elemental analyzer to determine the carbon, hydrogen, nitrogen and sulfur contents in the adsorbent. Physiochemical characterization has been performed to characterize the biochar properties. Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) were used to evaluate the functional groups and surface area of the biochar. Thermogravimetric analyzer (TGA) was used to discover the thermal properties, reactivity during adsorption. During the adsorption study, it was observed that raw sawdust biochar gasified at 850 °C gave the highest adsorption of 0.47 kg CO2/kg biochar at temperature of 30 °C. The incorporation of nitrogen functionalities onto the carbon surface may cause decrement of surface area of carbon