72 research outputs found

    Processing and Characterization of Activated Carbon from Coconut Shell and Palm Kernel Shell Waste by H3PO4 Activation

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    Palm kernel shell and coconut shell are used as a precursor for the production of activated carbon, a way of mitigating the tons of waste produced in Ghana. The raw Palm kernel shell and coconut shell were activated chemically using H3PO4. A maximum activated carbon yield of 26.3 g was obtained for Palm kernel shell and 22.9 g for coconut shell at 400oC, an impregnation ratio of 1.2 and 1-hour carbonization time. Scanning electron microscopy reveals well-developed cavities of the H3PO4 activated coconut shell and Palm kernel shell compared to the non-activated carbon. Iodine number of 743.02 mg/g and 682.11 mg/g, a porosity of 0.31 and 0.49 and the electrical conductivity of 2010 ÎŒS/cm and 778 ÎŒS /cm were obtained for the AC prepared from the coconut shell and Palm kernel shell respectively. The results of this work show that high-quality activated carbon can be manufactured locally from coconut shell and Palm kernel shell waste, and a scale-up of this production will go a long way to reduce the tons of coconut shell and Palm kernel shell waste generated in the country

    Cyclometalation of lanthanum(iii) based MOF for catalytic hydrogenation of carbon dioxide to formate

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    The hydrogenation of carbon dioxide (CO2) to formic acid is of great importance due to its useful properties in the chemical industry. In this work, we have prepared a novel metal-organic framework (MOF), JMS-1, using bipyridyl dicarboxylate linkers, with molecular formula [La2(bpdc)3(DMF)3]n. Network analysis of JMS-1 revealed a new 7-connected topology (zaz). The MOF backbone of the activated phase (JMS-1a) was functionalized by cyclometalation using [RuCl2(p-cymene)]2 to produce Ru(ii)@JMS-1a. Both JMS-1a and Ru(ii)@JMS-1a were able to convert CO2 in the presence of hydrogen to formate. Ru(ii)@JMS-1a displayed outstanding conversion evidenced by a yield of 98% of formate under optimized conditions of total pressure 50 bar (CO2/H2 = 1 : 4, temperature 110 \ub0C, time 24 h, 5 mmol KOH, 8 mL ethanol). This work is significant in providing new strategies of incorporating active catalytic centres in MOFs for efficient and selective conversion of CO2 to formate

    ICON 9-an international phase III randomized study to evaluate the efficacy of maintenance therapy with olaparib and cediranib or olaparib alone in patients with relapsed platinum-sensitive ovarian cancer following a response to platinum-based chemotherapy

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    BACKGROUND: Two novel biological agents-cediranib targeting angiogenesis, and olaparib targeting DNA repair processes-have individually led to an improvement in ovarian cancer control. The aim of ICON9 is to investigate the combination of cediranib and olaparib maintenance in recurrent ovarian cancer following platinum-based therapy. PRIMARY OBJECTIVE: To assess the efficacy of maintenance treatment with olaparib in combination with cediranib compared with olaparib alone following a response to platinum-based chemotherapy in women with platinum-sensitive ovarian, fallopian tube or peritoneal cancer during first relapse. STUDY HYPOTHESIS: Maintenance therapy with cediranib and olaparib in combination is associated with improved patient outcomes compared with olaparib alone. TRIAL DESIGN: International phase III randomized controlled trial. Following a response to platinum-based chemotherapy patients are randomized 1:1 to either oral olaparib and cediranib (intervention arm) or oral olaparib alone (control arm). MAJOR INCLUSION CRITERIA: Patients with a known diagnosis of high grade serous or endometrioid carcinoma of the ovary, fallopian tube or peritoneum, progressing more than 6 months after first-line platinum-based chemotherapy, who have responded to second-line platinum-based chemotherapy. PRIMARY ENDPOINTS: Progression-free and overall survival. Co-primary endpoints to be assessed using a fixed-sequence gatekeeping approach: (1) progression-free survival, all patients; (2) progression-free survival, BRCA wild type; (3) overall survival, all patients; (4) overall survival, BRCA wild type. SAMPLE SIZE: 618 patients will be recruited. ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: Accrual is expected to be completed in 2024 with presentation of results in 2025. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03278717

    Comparative assessment of genetic diversity matrices and clustering methods in white Guinea yam (Dioscorea rotundata) based on morphological and molecular markers

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    Open Access Journal; Published online: 06 Aug 2020Understanding the diversity and genetic relationships among and within crop germplasm is invaluable for genetic improvement. This study assessed genetic diversity in a panel of 173 D. rotundata accessions using joint analysis for 23 morphological traits and 136,429 SNP markers from the whole-genome resequencing platform. Various diversity matrices and clustering methods were evaluated for a comprehensive characterization of genetic diversity in white Guinea yam from West Africa at phenotypic and molecular levels. The translation of the different diversity matrices from the phenotypic and genomic information into distinct groups varied with the hierarchal clustering methods used. Gower distance matrix based on phenotypic data and identity by state (IBS) distance matrix based on SNP data with the UPGMA clustering method found the best fit to dissect the genetic relationship in current set materials. However, the grouping pattern was inconsistent (r = − 0.05) between the morphological and molecular distance matrices due to the non-overlapping information between the two data types. Joint analysis for the phenotypic and molecular information maximized a comprehensive estimate of the actual diversity in the evaluated materials. The results from our study provide valuable insights for measuring quantitative genetic variability for breeding and genetic studies in yam and other root and tuber crops

    Interpenetrated Magnesium–Tricalcium Phosphate Composite: Manufacture, Characterization and In Vitro Degradation Test

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    Magnesium and calcium phosphates composites are promising biomaterials to create biodegradable load-bearing implants for bone regeneration. The present investigation is focused on the design of an interpenetrated magnesium–tricalcium phosphate (Mg–TCP) composite and its evaluation under immersion test. In the study, TCP porous preforms were fabricated by robocasting to have a prefect control of porosity and pore size and later infiltrated with pure commercial Mg through current-assisted metal infiltration (CAMI) technique. The microstructure, composition, distribution of phases and degradation of the composite under physiological simulated conditions were analysed by scanning electron microscopy, elemental chemical analysis and X-ray diffraction. The results revealed that robocast TCP preforms were full infiltrated by magnesium through CAMI, even small pores below 2 lm have been filled with Mg, giving to the composite a good interpenetration. The degradation rate of the Mg–TCP composite displays lower value compared to the one of pure Mg during the first 24 h of immersion test.Magnesium and calcium phosphates composites are promising biomaterials to create biodegradable load-bearing implants for bone regeneration. The present investigation is focused on the design of an interpenetrated magnesium–tricalcium phosphate (Mg–TCP) composite and its evaluation under immersion test. In the study, TCP porous preforms were fabricated by robocasting to have a prefect control of porosity and pore size and later infiltrated with pure commercial Mg through current-assisted metal infiltration (CAMI) technique. The microstructure, composition, distribution of phases and degradation of the composite under physiological simulated conditions were analysed by scanning electron microscopy, elemental chemical analysis and X-ray diffraction. The results revealed that robocast TCP preforms were full infiltrated by magnesium through CAMI, even small pores below 2 lm have been filled with Mg, giving to the composite a good interpenetration. The degradation rate of the Mg–TCP composite displays lower value compared to the one of pure Mg during the first 24 h of immersion test

    A combined experimental and simulation method for appraising the energy performance of green roofs in Ningbo's Chinese climate

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    A passive means of lowering the energy demand of buildings is the application of green roofs. The complexity between heat and moisture exchanges in green roof layers and the large variations of green roof types make the need for experimental or simulation assessments necessary for quantifying the energy benefits from green roofs. The current treatment of green roofs in simulation programs is either over-simplistic, for example by ignoring heat and moisture exchanges such as evapotranspiration, or the more advanced models have limitations and require inputs that are rarely available in practice. In this paper a combination of experimental and modelling techniques are used to assess the potential heating and cooling load reductions from the application of green roofs in the subtropical climate of Ningbo in China. The method provides a generalised energy performance assessment of green roofs in Ningbo by overcoming the limitations of existing gre
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