163 research outputs found

    Meningkatkan Hasil Belajar Siswa Kelas IV SD Kristen Belso A2 Ambon dengan Menggunakan Model Pembelajaran Double Loop Problem Solving pada Materi Pengukuran Panjang dan Berat

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    This study aims to determine whether there is an increase in students' learning outcomes taught using Double Loop Problem Solving (DLPS) on the measurement material. The design of this study was a pre-experimental design with one group pre test post test design. The research sample was sixth grades which amounted to 24 people. The research techniques used were test and non-test techniques. Analysis of student learning outcomes data descriptively obtained from the results of percentages and average students while to determine the increase in student learning outcomes, we used the N-gain test formula. The results showed that using of the Double Loop Problem Solving (DLPS) learning model could improve student learning outcomes in the measurement material. This is supported by a pre-test and post-test analysis that uses normalized N-gain values where 21% of students are in the N-gain category with a High category, 58% of students are in the moderate category and 21% are in the low categor

    Suctioning of clear amniotic fluid at birth: A systematic review

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    Context Upper airway suctioning at birth was considered standard procedure and is still commonly practiced. Negative effects could exceed benefits of suction. Question In infants born through clear amniotic fluid (P) does suctioning of the mouth and nose (I) vs no suctioning (C) improve outcomes (O). Data sources Information specialist conducted literature search (12th September 2021, re-run 17th June 2022) using Medline, Embase, Cochrane Databases, Database of Abstracts of Reviews of Effects, and CINAHL. RCTs, non-RCTs and observational studies with a defined selection strategy were included. Unpublished studies, reviews, editorials, animal and manikin studies were excluded. Data extraction Two authors independently extracted data, risk of bias was assessed using the Cochrane ROB2 and ROBINS-I tools. Certainty of evidence was assed using the GRADE framework. Review Manager was used to analyse data and GRADEPro to develop summary of evidence tables. Meta-analyses were performed if ≥2 RCTs were available. Outcomes Primary: assisted ventilation. Secondary: advanced resuscitation, oxygen supplementation, adverse effects of suctioning, unanticipated NICU admission. Results Nine RCTs (n = 1096) and 2 observational studies (n = 418) were identified. Two RCTs (n = 280) with data concerns were excluded post-hoc. Meta-analysis of 3 RCTs, (n = 702) showed no difference in primary outcome. Two RCTs (n = 200) and 2 prospective observational studies (n = 418) found lower oxygen saturations in first 10 minutes of life with suctioning. Two RCTs (n = 200) showed suctioned newborns took longer to achieve target saturations. Limitations Certainty of evidence was low or very low for all outcomes. Most studies selected healthy newborns limiting generalisability and insufficient data was available for planned subgroup analyses. Conclusions Despite low certainty evidence, this review suggests no clinical benefit from suctioning clear amniotic fluid from infants following birth, with some evidence suggesting a resulting desaturation. These finding support current guideline recommendations that this practice is not used as a routine step in birth.publishedVersio

    Polyoxymethylene (POM) integrity resulting from its dependencies on material geometries and processing methodology

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    POM-copolymer bond breaking leads to change depending with respect to processing methodology and material geometries. This paper present the oversights effect on the material integrity due to different geometries and processing methodology. Thermo-analytical methods with reference were used to examine the degradation of thermomechanical while Thermogravimetric Analysis (TGA) was used to judge the thermal stability of sample from its major decomposition temperature. Differential Scanning Calorimetry (DSC) investigation performed to identify the thermal behaviour and thermal properties of materials. The result shown that plastic gear geometries with injection molding at higher tonnage machine more stable thermally rather than resin geometries. Injection plastic gear geometries at low tonnage machine faced major decomposition temperatures at 313.61˚C, 305.76 ˚C and 307.91 ˚C while higher tonnage processing method are fully decomposed at 890˚C, significantly higher compared to low tonnage condition and resin geometries specimen at 398˚C. Chemical composition of plastic gear geometries with injection molding at higher and lower tonnage are compare based on their moisture and VOC content, polymeric material content and the absence of filler. Results of higher moisture and VOC content are report in resin geometries (0.120%) compared to higher tonnage of injection plastic gear geometries which is 1.264%. The higher tonnage of injection plastic gear geometry are less sensitive to thermo-mechanical degradation due to polymer chain length and molecular weight of material properties such as tensile strength, flexural strength, fatigue strength and creep resistance

    Simulation study on enhancing hydrogen production in an ocean thermal energy (OTEC) system utilizing a solar collector

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    This article reports the simulation study on the performance of utilizing a solar collector at the inlet of an evaporator to provide auxiliary heat into a system for hydrogen generation in an OTEC cycle. The conventional method of OTEC is simulated by FORTRAN programming and the results were compared with the presence of solar collector on the system. In the simulation experimental, the incoming temperature of warm seawater was boosted by using a flat plate solar collector. For the purpose of the experiment, a 100 kW OTEC cycle that was designed incorporated a solar boosting capability. Its thermodynamic efficiency was then compared through a series of simulation involving several control parameters. The results reveal that the proposed solar boosted OTEC enhanced the thermal efficiency, TE. Increase in solar power absorption can increase the net power output, thus increasing the amount of hydrogen produced. The results obtained provided insights, from a thermodynamic perspective, on the outcome of combining sustainable energy with solar thermal energy to improve the system performance

    Developing community energy systems to facilitate Ethiopia's transition to sustainable energy

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    In Ethiopia, renewable energy offers people an affordable, dependable, and eco-friendly power supply while decreasing the carbon footprint. However, delivering a renewable future for the country requires a massive change in social practices and systems of provision. The slow progress of renewable development is hindering the transition to a cleaner energy future. Over 80 % of people live in rural areas where it is expensive to reach them via grid networks in Ethiopia, requiring off-grid alternatives. Community energy systems, which are off-grid energy systems in which communities play a key role, offer alternative strategies to close the country's energy access gap. However, community energy systems remain underdeveloped in Ethiopia. There is a need to understand the opportunities for community energy and the barriers that hinder its development in Ethiopia, and their role in energy transitions. This paper adopts an experimental lens to understand the diverse dimensions of community energy projects through how they are made, maintained, and lived. Using a comparative analysis of three multi-method, qualitative case studies, this paper argues that the political context poses the biggest obstacle to the development of community energy in Ethiopia despite these projects' tangible benefits. The analysis indicates that community energy projects allow communities to be involved in all stages of project development. In every project, communities assume project management responsibilities after commissioning. However, these projects encounter challenges in resourcing capital, managing supply chains, and building necessary skills among community members to understand business models to ensure sustained operation of the systems

    Selective oxidation of methane to methanol using supported AuPd catalysts prepared by stabilizer-free sol-immobilization

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    The selective oxidation of methane to methanol, using H<sub>2</sub>O<sub>2</sub>, under mild reaction conditions was studied using bimetallic 1 wt % AuPd/TiO<sub>2</sub> prepared by stabilizer-free sol-immobilization. The as-prepared catalysts exhibited low, unselective oxidation activity and deleterious H<sub>2</sub>O<sub>2</sub> decomposition, which was ascribed to the small mean particle size of the supported AuPd nanoparticles. Heat treatments were employed to facilitate particle size growth, yielding an improvement in the catalyst turnover frequency and decreasing the H<sub>2</sub>O<sub>2</sub> decomposition rate. The effect of support phase was studied by preparing a range of AuPd catalysts supported on rutile TiO<sub>2</sub>. The low surface area rutile TiO<sub>2</sub> yielded catalysts with effective oxygenate production but poor H<sub>2</sub>O<sub>2</sub> utilization. The influence of the rutile-TiO<sub>2</sub> support was investigated further by producing catalysts with a lower metal loading to maintain a consistent metal loading per square meter compared to the 1 wt % AuPd/P25 TiO<sub>2</sub> catalyst. When calcined at 800 °C, the 0.13 wt % AuPd catalyst demonstrated significantly improved turnover frequency of 103 h<sup>–1</sup>. In contrast, the turnover frequency was found to be ca. 2 h<sup>–1</sup> for the rutile-supported 1 wt % AuPd catalyst calcined at 800 °C. The catalysts were probed by electron microscopy and X-ray photoelectron spectroscopy to understand the influence of particle size and oxidation state on the utilization of H<sub>2</sub>O<sub>2</sub> and oxygenate productivity. This work shows that the key to highly active catalysts involves the prevention of deleterious H<sub>2</sub>O<sub>2</sub> decomposition, and this can be achieved through carefully controlling the nanoparticle size, metal loading, and metal oxidation state

    D-band point to multi-point deployment with G-band transport

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    The first Point to MultiPoint wireless system at D-band has been designed and is in advanced development. The European Commission H2020 ULTRAWAVE "Ultra capacity wireless layer beyond 100 GHz based on millimeter wave Traveling Wave Tubes"project aims to respond to the demand of high capacity at level of tens of Gigabit per second, in urban areas, where fiber backhaul is not economically viable and high density small cell architectures are deployed. A transmission hub powered by a novel D-band TWTs will feed a number of terminals arbitrarily allocated in the corresponding area sector. This paper illustrates the main characteristics, advantages and networking aspects and provide a summary of the latest results of the ULTRAWAVE project

    Investigating the influence of acid sites in continuous methane oxidation with N2O over Fe/MFI zeolites

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    Methane oxidation using N2O was carried out with Fe–MFI zeolite catalysts at 300 °C. Methane conversion over Fe–ZSM-5, Fe–silicalite-1 and Fe–TS-1 indicates that Brønsted acidity is required to support the Fe-based alpha-oxygen active site for the important initial hydrogen abstraction step. Increasing the calcination temperature of Fe–ZSM-5 from 550 to 950 °C showed that the catalyst retained the MFI structure. However, at 950 °C the Brønsted and Lewis acid sites were altered significantly due to the migration of aluminium, which led to a significant decrease in catalytic performance. Over Fe–ZSM-5 the desired partial oxidation product, methanol was observed to undergo a reaction path similar to the methanol to olefin (MTO) process, which predominately produced ethene and subsequently produced coke. Methanol control experiments over Fe–silicalite-1, Fe–ZSM-5, Fe–TS-1 and H–ZSM-5 indicated that with the presence of Brønsted acidity the catalysts were more effective at forming ethene and subsequent aromatic species from DME, which resulted in an increased level of catalyst fouling. The implication of these observations is that the desorption of methanol is crucial to afford high mass balances and selectivity, however, Brønsted acid sites appear to slow this rate. These sites appear to effectively retain methanol and DME under reaction conditions, leading to low mass balances being observed. Our results confirm that to afford efficient and continuous methane oxidation by N2O, the catalytic active site must be Fe coordinated to Al

    Occurrence of Ancylostoma in dogs, cats and public places from Andradina city, São Paulo state, Brazil

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    The aim of this study was to determine the frequency and intensity of Ancylostoma spp. in 33 dogs and 52 cats by means of coproparasitological examinations and parasitological necropsy, and assess the presence of contaminated feces with eggs of that parasite in public places of Andradina Municipality, São Paulo State, Brazil. Willis-Mollay and Sedimentation methods indicated Ancylostoma spp. eggs in 87.8% (29/33) dogs and 94.2% (49/52) cats. The species A. caninum and A. braziliense were found in 63.6% (21/33) and 30.3% (10/33) of dogs, respectively. Considering cats, 67.3% (35/52) were parasitized by A. braziliense, 21.1% (11/52) by A. caninum, and 9.6% (5/52) by A. tubaeforme. Forty-two canine fecal samples were collected from public environments, including 23 squares/gardens and 19 streets/sidewalks. Positive samples for Ancylostoma spp. accounted for 64.3% (27/42); squares/gardens had 60.9% (14/23) positive samples, and streets and sidewalks, 68.4% (13/19). No association was observed between the number of Ancylostoma spp parasites and age, sex and breed of the animals and also the ratio of EPG counts and the parasitic intensity observed at necropsy (p > 0.05). Based on the high occurrence of hookworm in dogs and cats in this study, the treatment with anti helminthics are needed even in those animals with negative stool tests, besides adopting control of the number of animals in public places, in order to decrease the likelihood of environmental contamination, since this parasite represents a potential hazard to human and animal health
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