Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the sof...Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.Three CCDs have been characterised,the two flight devices and the flight spa re.This has been carried out at the Open University in a bespo ke cleanroom measure ment facility.The results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.The se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented.展开更多
Since their discovery, zeolites have generated significant interest in various technological fields, such as molecular sieves, ion exchangers, catalysts, and especially as adsorbents. This article focuses on character...Since their discovery, zeolites have generated significant interest in various technological fields, such as molecular sieves, ion exchangers, catalysts, and especially as adsorbents. This article focuses on characterizing the types of zeolites present in Sangarédi bauxite. To achieve this objective, we conducted a physico-chemical characterization (moisture, particle size, volumetric density, porosity) and determined the optimal conditions for activating the zeolite samples (15% H2SO4 concentration, L/S ratio of 2, temperature of 70˚C, duration of 3 hours). Techniques used to characterize the samples included desiccation gravimetry, mechanical sieving, X-ray fluorescence (atomic percentage), X-ray diffraction, BET method, and water pycnometry. Additionally, we assessed the adsorption capacity of zeolites activated by the elimination of methylene blue in an aqueous solution, which was selected as a model water pollutant. According to X-ray fluorescence and diffraction data, there are nine types of zeolite in Sangarédi bauxite, divided into five families. Regarding physical activation, a good porous structure was observed at a temperature of 300˚C to 340˚C for 4 hours. Above this range, material condensation occurs, leading to a sudden increase in mass loss, which can be explained by a change in their crystalline structure. After treatment with sulfuric acid, the activated samples showed an increase in specific surface area (from 72 to 130.25 m2∙g−1 on average) and porosity (from 0.07% to 0.3%), as well as an increased susceptibility to methylene blue discoloration (from 13.58% to 30.35%). These results confirm the improvement in the microporous structure and the formation of a more developed molecular sieve network. Thanks to the identified structural and textural characteristics, it can be concluded that the activated zeolites obtained are extremely reactive materials and can be used effectively in water treatment.展开更多
The materials studied were lateritic soils from Souza-Mbanga-Cameroon, with a view to their better use in road geotechnics. In order to achieve the set objective, the work was carried out in two phases, firstly in the...The materials studied were lateritic soils from Souza-Mbanga-Cameroon, with a view to their better use in road geotechnics. In order to achieve the set objective, the work was carried out in two phases, firstly in the field, to provide a morpho-structural description of the soil profiles, followed by a laboratory phase to analyse the samples collected in the field. The results of the physical characterisation of the soil samples show that, for average values, the water content is 9.87%, the percentage of fines 48%, the plasticity index 21.6%, the liquidity limit 50.91%, and the consistency index 1.97. These soils are classified as silty sands in the LCPC classification and as fine soils in the GTR classification. The average value of the maximum dry density is 1.81 g/cm<sup>3</sup> and that of the water content at the modified Proctor optimum is 16.24%. The CBR index is between 1.8% and 17.8%, showing that these soils belong to classes S1, S2, S3, S4 and S5. Souza-Mbanga lateritic soils can be used in their natural state as subgrades.展开更多
The 'Industry 4.0' era is characterised by a series of new digital technologies, which affect every link of the vertical value chain and are the important driving force of world change. Digitalisation creates ...The 'Industry 4.0' era is characterised by a series of new digital technologies, which affect every link of the vertical value chain and are the important driving force of world change. Digitalisation creates new jobs for people and creates more value for businesses.展开更多
Laser scanning can provide timely assessments of mine sites despite adverse challenges in the operational environment.Although there are several published articles on laser scanning,there is a need to review them in t...Laser scanning can provide timely assessments of mine sites despite adverse challenges in the operational environment.Although there are several published articles on laser scanning,there is a need to review them in the context of underground mining applications.To this end,a holistic review of laser scanning is presented including progress in 3D scanning systems,data capture/processing techniques and primary applications in underground mines.Laser scanning technology has advanced significantly in terms of mobility and mapping,but there are constraints in coherent and consistent data collection at certain mines due to feature deficiency,dynamics,and environmental influences such as dust and water.Studies suggest that laser scanning has matured over the years for change detection,clearance measurements and structure mapping applications.However,there is scope for improvements in lithology identification,surface parameter measurements,logistic tracking and autonomous navigation.Laser scanning has the potential to provide real-time solutions but the lack of infrastructure in underground mines for data transfer,geodetic networking and processing capacity remain limiting factors.Nevertheless,laser scanners are becoming an integral part of mine automation thanks to their affordability,accuracy and mobility,which should support their widespread usage in years to come.展开更多
Overhanging rock slopes(steeper than 90°) are typically avoided in rock engineering design, particularly where the scale of the slope exceeds the scale of fracturing present in the rock mass. This paper highlight...Overhanging rock slopes(steeper than 90°) are typically avoided in rock engineering design, particularly where the scale of the slope exceeds the scale of fracturing present in the rock mass. This paper highlights an integrated approach of designing overhanging rock slopes where the relative dimensions of the slope exceed the scale of fracturing and the rock mass failure needs to be considered rather than kinematic release of individual blocks. The key to the method is a simplified limit equilibrium(LE) tool that was used for the support design and analysis of a multi-faceted overhanging rock slope. The overhanging slopes required complex geometries with constantly changing orientations. The overhanging rock varied in height from 30 m to 66 m. Geomechanical modelling combined with discrete fracture network(DFN)representation of the rock mass was used to validate the rock mass strength assumptions and the failure mechanism assumed in the LE model. The advantage of the simplified LE method is that buttress and support design iterations(along with sensitivity analysis of design parameters) can be completed for various cross-sections along the proposed overhanging rock sections in an efficient manner, compared to the more time-intensive, sophisticated methods that were used for the initial validation. The method described presents the development of this design tool and assumptions made for a specific overhanging rock slope design. Other locations will have different geological conditions that can control the potential behaviour of rock slopes, however, the approach presented can be applied as a general guiding design principle for overhanging rock cut slope.展开更多
C-type lysozyme genes （Lyzls） belong to the class of lysozymes and are highly expressed in the testis and epididymis. The members Lyzl4 and Spaca3 have been reported to play a role in sperm-egg binding and fertilisa...C-type lysozyme genes （Lyzls） belong to the class of lysozymes and are highly expressed in the testis and epididymis. The members Lyzl4 and Spaca3 have been reported to play a role in sperm-egg binding and fertilisation in mice. However, the function of the remaining two mouse c-type lysozyme genes, Lyzll and Lyzl6, is still not clear. In the present study, we analysed the tissue expression and androgen-dependent expression of mouse c-type lysozyme genes and the possible contribution of human recombinant LYZL6 （rLYZL6） to immunity. The expression of Lyzlswas detected by RT-PCR, Western blots, immunohistochemistry and immunofluorescence. The bacteriolytic activity of rLYZL6 was analysed by a colony-forming assay. In mice, the expression of Lyzlgenes was mainly in the testis and epididymis in a developmentally regulated manner and androgen- or testicular factor-regulated manner. Immunodetection revealed the presence of LYZL6 protein in primary spermatocytes and round spermatids of the testis and on the post-acrosomal area and midpiece of mature epididymal spermatozoa. The rLYZL6 protein exhibited antibacterial activity. From the results, Lyzls may play a role in mitochondrial function of spermatozoa and LYZL6 may contribute to the innate immunity of the male genital tract.展开更多
Novel applications of nanotechnology may lead to the release of engineered nanoparticles（ENPs）, which result in concerns over their potential environmental hazardous impact. It is essential for the research workers ...Novel applications of nanotechnology may lead to the release of engineered nanoparticles（ENPs）, which result in concerns over their potential environmental hazardous impact. It is essential for the research workers to be able to quantitatively characterise ENPs in the environment and subsequently to assist the risk assessment of the ENPs. This study hence explored the application of nanoparticle tracking system（NTA） to quantitatively describe the behaviour of the ENPs in natural sediment-water systems. The NTA allows the measurement of both particle number concentration（PNC） and particle size distribution（PSD） of the ENPs. The developed NTA method was applied to a range of gold and magnetite ENPs with a selection of surface properties. The results showed that the positively-charged ENPs interacted more strongly with the sediment than neutral and negatively-charged ENPs. It was also found that the citrate coated Au ENPs had a higher distribution percentage（53%） than 11-mercaptoundecanoic acid coated Au ENPs（20%） and citrate coated magnetite ENPs（21%）. The principles of the electrostatic interactions between hard（and soft） acids and bases（HSAB） are used to explain such behaviours; the hard base coating（i.e. citrate ions） will interact more strongly with hard acid（i.e. magnetite） than soft acid（i.e. gold）.The results indicate that NTA is a complementary method to existing approaches to characterise the fate and behaviour of ENPs in natural sediment.展开更多
C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)...C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)activated heterogeneous catalysis offers a number of advantages,such as relatively mild reaction conditions and energy efficiency,in comparison to the conventional thermal catalysis.This review presents the state-of-the-art for the application of NTP-catalysis towards C1 chemistry,including the CO2 hydrogenation,reforming of CH4 and CH3OH,and water-gas shift(WGS)reaction.In the hybrid NTP-catalyst system,the plasma-catalyst interactions aremultifaceted.Accordingly,this reviewalso includes a brief discussion on the fundamental research into themechanisms of NTP activated catalytic C1 chemistry,such as the advanced characterisation methods(e.g.,in situ diffuse reflectance infrared Fourier transform spectroscopy,DRIFTS),temperatureprogrammed plasma surface reaction(TPPSR),kinetic studies.Finally,prospects for the future research on the development of tailor-made catalysts for NTP-catalysis systems(which will enable the further understanding of its mechanism)and the translation of the hybrid technique to practical applications of catalytic C1 chemistry are discussed.展开更多
The. objectives.of this study are to convert at laboratory s.cale agric.ultural residues into activated carbons （AC） with specific properties, to characterize them and to test them in adsorption reactor for tetracyc...The. objectives.of this study are to convert at laboratory s.cale agric.ultural residues into activated carbons （AC） with specific properties, to characterize them and to test them in adsorption reactor for tetracycline removal, a common antibiotic. Two new ACs were produced by direct activation with steam from beet pulp （BP-H2O） and peanut hu_lls （PH-H2O） in environmental friendly conditions BP-H2O and PH-H2Opresentcarbon content rangedcarbons with different intrinsic properties.展开更多
Flexible strip supercapacitors are developed and their electrochemical properties are characterized. Activated carbon is used as the electrode material and it is found to have a good porous structure which provides a ...Flexible strip supercapacitors are developed and their electrochemical properties are characterized. Activated carbon is used as the electrode material and it is found to have a good porous structure which provides a large surface area for energy storage.Furthermore, this activated carbon performs well. The manufacturing processes for the supercapacitors are described in detail and the preparation process has good reproducibility. The strip supercapacitors are combined in series and parallel to measure their electrical properties. The performances of these two samples in series or in parallel both follow the theoretical models. The electrochemical potential window of a series circuit of these two strip supercapacitors is 4.8 V. The energy and power of the series or parallel circuits are equal to the sums of the two strip supercapacitors.展开更多
The feasibility of durian tree sawdust (DTS), coconut coir (CC) and oil palm empty fruit bunch (EFB) as low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. T...The feasibility of durian tree sawdust (DTS), coconut coir (CC) and oil palm empty fruit bunch (EFB) as low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. The effects of solution pH and initial metal concentration on adsorption capacity were examined in batch experiments. The affinity and the adsorption capacity of DTS, CC and EFB were evaluated. The adsorption behaviour of Cu(II), Pb(II) and Zn(II) ions onto DTS, CC and EFB was described using Freundlich and Langmuir isotherm models. The separation factor (RL) analysis suggests that the removal of metal ions onto three agricultural wastes studied was favourable. The maximum adsorption capacities (Q) estimated from the Langmuir isotherm model for Cu(II), Pb(II) and Zn(II) were 18.42, 20.37 and 22.78 mg/g for DTS, 18.38, 37.04 and 24.39 mg/g for CC, and 26.95, 37.59 and 21.19 mg/g for EFB, respectively. The characterisation studies were carried out using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDX) and Fourier Transform Infrared Spectrometer (FTIR). The surface morphology of the biosorbents changed significantly following interaction with metal ions. The primary adsorption mechanism was complexation between metal ions and binding sites of biosorbents. Both hydroxyl and amine groups are the main binding sites in DTS, CC and EFB.展开更多
The development of a pseudo-one pot synthesis of 3（5）,4-dinitropyrazole enabled us to use it as a starting material for energetic plasticisers. Its acidic proton allowed simple derivatisation on one of the ring nitr...The development of a pseudo-one pot synthesis of 3（5）,4-dinitropyrazole enabled us to use it as a starting material for energetic plasticisers. Its acidic proton allowed simple derivatisation on one of the ring nitrogens. The thermal characteristics of two derivatives were evaluated. For instance, the N-allyl compound was a liquid with very low glass transition temperature, whereas the N-propargyl compound was a sticky solid at ambient temperature. The two compounds were both thermally stable according to STANAG 4582.展开更多
This study is done with the aim to bring together the various antimicrobial peptides that are present in the crustacean hemolymph and their sources along with its characteristics.Invertebrates lack immune systems that...This study is done with the aim to bring together the various antimicrobial peptides that are present in the crustacean hemolymph and their sources along with its characteristics.Invertebrates lack immune systems that involve antigen-antibody reactions and do not have an immune memory, therefore most invertebrate species show no evidence of acquired immunity.Crustaceans possess an open circulatory system, where nutrients, oxygen, hormones, and cells are distributed in the hemolymph. They lack adaptive immune system and rely exclusively on their innate immune mechanisms that include both cellular and humoral responses. Antimicrobial peptides and proteins form an important means of host defense in eukaryotes. In addition to their role as endogenous antibiotics, antimicrobial peptides have functions in inflammation,wound repair and regulation of the adaptive immune system. Over the past several years, many antimicrobial peptides have been found and characterized in crabs.展开更多
The efficacy of coconut tree sawdust (CTS), eggshell (ES) and sugarcane bagasse (SB) as alternative low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. Batch...The efficacy of coconut tree sawdust (CTS), eggshell (ES) and sugarcane bagasse (SB) as alternative low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. Batch adsorption studies were carried out to evaluate the effects of solution pH and initial metal concentration on adsorption capacity. The optimum biosorption condition was found at pH 6.0, 0.1 g biomass dosage and at 90 min equilibrium time. The adsorption data were fitted to the Freundlich and Langmuir isotherm models. The adsorption capacity and affinity of CTS, ES and SB were evaluated. The Freundlich constant (n) and separation factor (RL) values suggest that the metal ions were favourably adsorbed onto biosorbents. The maximum adsorption capacities (Q) estimated from the Langmuir isotherm model for Cu(II), Pb(II) and Zn(II) were 3.89, 25.00 and 23.81 mg/g for CTS, 34.48, 90.90 and 35.71 mg/g for ES, and 3.65, 21.28 and 40.00 mg/g for SB, respectively. The characterisation studies were performed using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDX) and Fourier Transform Infrared Spectrometer (FTIR). Interaction with metal ions led to the formation of discrete aggregates on the biosorbents surface. The metal ions bound to the active sites of the biosorbents through either electrostatic attraction or complexation mechanism.展开更多
Nanocomposite hydrogels are the combination of known components that are a hydrogel and nanometre-sized fillers,typically leading to improved mechanical properties or new functionalities.With simplicity of design and ...Nanocomposite hydrogels are the combination of known components that are a hydrogel and nanometre-sized fillers,typically leading to improved mechanical properties or new functionalities.With simplicity of design and ease of synthesis,recent advances have highlighted that this family of hydrogels holds the significant promise of application in diverse biomedical and engineering fields.The elaborate design and investigation as well as suitable application of nanocomposite hydrogels require the synergy of mechanics,materials science,engineering,and biology.Despite similarities in design and fabrication,the data of mechanical properties for nanocomposite hydrogels scatter in a large space.It is worthwhile comparing various nanocomposite hydrogels for similarities and differences in mechanical properties to aid in designing novel hydrogels with extreme properties,and guide practical applications.This review aims to fill,in the literature,the missing gap of addressing mechanical measurement methods and comparison of mechanical properties in this ever-evolving broad area of research.Finally,the challenges and future research opportunities are highlighted.展开更多
Isotropy in microstructure and mechanical properties remains a challenge for laser powder bed fusion(LPBF)processed materials due to the epitaxial growth and rapid cooling in LPBF.In this study,a high-strength TiB_(2)...Isotropy in microstructure and mechanical properties remains a challenge for laser powder bed fusion(LPBF)processed materials due to the epitaxial growth and rapid cooling in LPBF.In this study,a high-strength TiB_(2)/Al-Cu composite with random texture was successfully fabricated by laser powder bed fusion(LPBF)using pre-doped TiB_(2)/Al-Cu composite powder.A series of advanced characterisation techniques,including synchrotron X-ray tomography,correlative focussed ion beam-scanning electron microscopy(FIB-SEM),scanning transmission electron microscopy(STEM),and synchrotron in situ X-ray diffraction,were applied to investigate the defects and microstructure of the as-fabricated TiB_(2)/Al-Cu composite across multiple length scales.The study showed ultra-fine grains with an average grain size of about 0.86μm,and a random texture was formed in the as-fabricated condition due to rapid solidification and the TiB_(2)particles promoting heterogeneous nucleation.The yield strength and total elongation of the as-fabricated composite were 317 MPa and 10%,respectively.The contributions of fine grains,solid solutions,dislocations,particles,and Guinier-Preston(GP)zones were calculated.Failure was found to be initiated from the largest lack-of-fusion pore,as revealed by in situ synchrotron tomography during tensile loading.In situ synchrotron diffraction was used to characterise the lattice strain evolution during tensile loading,providing important data for the development of crystal-plasticity models.展开更多
Thermal plasma technology provides a stable and long term treatment of mixed wastes through vitrification processes. In this work, a transferred plasma system was realized to vitrify mixed wastes, taking advantage of ...Thermal plasma technology provides a stable and long term treatment of mixed wastes through vitrification processes. In this work, a transferred plasma system was realized to vitrify mixed wastes, taking advantage of its high power density, enthalpy and chemical reactivity as well as its rapid quenching and high operation temperatures. To characterize the plasma discharge, a temperature diagnostic is realized by means of optical emission spectroscopy （OES）. To typify the morphological structure of the wastes samples~ scan- ning electron microscopy （SEM）, and X-ray diffraction （XRD） techniques were applied before and after the plasma treatment.展开更多
This thesis gives overview of the connotation of rural spatial structure,indicating 4 kinds of elements,namely nodus,passage,region and flow.Their spatial arrangement and interaction lead to the corresponding rural sp...This thesis gives overview of the connotation of rural spatial structure,indicating 4 kinds of elements,namely nodus,passage,region and flow.Their spatial arrangement and interaction lead to the corresponding rural spatial structure.This thesis also offers panorama of the related theoretical progress of intra-county and rural areas,indicating that the research theories of regional spatial structure at present,mainly focus on macroscopic region or urban space,but there is shortage of researches on county spatial structure,especially microscopic rural spatial structure.On such basis,4 kinds of theoretical models and characteristics of regional spatial structure have been introduced.We build analysis index system of rural structural elements on the basis of 4 elements,and conduct rural spatial structural analysis,taking Jinhu County as an example.The result shows that rural spatial structure in Jinhu County is still at stage of nucleus-cluster development and rural system is not so sound.In addition,the passage network system of infrastructure has not taken shape,and county economy presents diseconomy of scale.The spatial interaction and association among towns in Jinhu County are weak.The characteristic analysis model of spatial structure in this research can objectively reflect regional characteristic of spatial structure.展开更多
文摘Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.Three CCDs have been characterised,the two flight devices and the flight spa re.This has been carried out at the Open University in a bespo ke cleanroom measure ment facility.The results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.The se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented.
文摘Since their discovery, zeolites have generated significant interest in various technological fields, such as molecular sieves, ion exchangers, catalysts, and especially as adsorbents. This article focuses on characterizing the types of zeolites present in Sangarédi bauxite. To achieve this objective, we conducted a physico-chemical characterization (moisture, particle size, volumetric density, porosity) and determined the optimal conditions for activating the zeolite samples (15% H2SO4 concentration, L/S ratio of 2, temperature of 70˚C, duration of 3 hours). Techniques used to characterize the samples included desiccation gravimetry, mechanical sieving, X-ray fluorescence (atomic percentage), X-ray diffraction, BET method, and water pycnometry. Additionally, we assessed the adsorption capacity of zeolites activated by the elimination of methylene blue in an aqueous solution, which was selected as a model water pollutant. According to X-ray fluorescence and diffraction data, there are nine types of zeolite in Sangarédi bauxite, divided into five families. Regarding physical activation, a good porous structure was observed at a temperature of 300˚C to 340˚C for 4 hours. Above this range, material condensation occurs, leading to a sudden increase in mass loss, which can be explained by a change in their crystalline structure. After treatment with sulfuric acid, the activated samples showed an increase in specific surface area (from 72 to 130.25 m2∙g−1 on average) and porosity (from 0.07% to 0.3%), as well as an increased susceptibility to methylene blue discoloration (from 13.58% to 30.35%). These results confirm the improvement in the microporous structure and the formation of a more developed molecular sieve network. Thanks to the identified structural and textural characteristics, it can be concluded that the activated zeolites obtained are extremely reactive materials and can be used effectively in water treatment.
文摘The materials studied were lateritic soils from Souza-Mbanga-Cameroon, with a view to their better use in road geotechnics. In order to achieve the set objective, the work was carried out in two phases, firstly in the field, to provide a morpho-structural description of the soil profiles, followed by a laboratory phase to analyse the samples collected in the field. The results of the physical characterisation of the soil samples show that, for average values, the water content is 9.87%, the percentage of fines 48%, the plasticity index 21.6%, the liquidity limit 50.91%, and the consistency index 1.97. These soils are classified as silty sands in the LCPC classification and as fine soils in the GTR classification. The average value of the maximum dry density is 1.81 g/cm<sup>3</sup> and that of the water content at the modified Proctor optimum is 16.24%. The CBR index is between 1.8% and 17.8%, showing that these soils belong to classes S1, S2, S3, S4 and S5. Souza-Mbanga lateritic soils can be used in their natural state as subgrades.
文摘The 'Industry 4.0' era is characterised by a series of new digital technologies, which affect every link of the vertical value chain and are the important driving force of world change. Digitalisation creates new jobs for people and creates more value for businesses.
基金the Australian Coal Industry’s Research Program(ACARP)(Project No.C27057).
文摘Laser scanning can provide timely assessments of mine sites despite adverse challenges in the operational environment.Although there are several published articles on laser scanning,there is a need to review them in the context of underground mining applications.To this end,a holistic review of laser scanning is presented including progress in 3D scanning systems,data capture/processing techniques and primary applications in underground mines.Laser scanning technology has advanced significantly in terms of mobility and mapping,but there are constraints in coherent and consistent data collection at certain mines due to feature deficiency,dynamics,and environmental influences such as dust and water.Studies suggest that laser scanning has matured over the years for change detection,clearance measurements and structure mapping applications.However,there is scope for improvements in lithology identification,surface parameter measurements,logistic tracking and autonomous navigation.Laser scanning has the potential to provide real-time solutions but the lack of infrastructure in underground mines for data transfer,geodetic networking and processing capacity remain limiting factors.Nevertheless,laser scanners are becoming an integral part of mine automation thanks to their affordability,accuracy and mobility,which should support their widespread usage in years to come.
文摘Overhanging rock slopes(steeper than 90°) are typically avoided in rock engineering design, particularly where the scale of the slope exceeds the scale of fracturing present in the rock mass. This paper highlights an integrated approach of designing overhanging rock slopes where the relative dimensions of the slope exceed the scale of fracturing and the rock mass failure needs to be considered rather than kinematic release of individual blocks. The key to the method is a simplified limit equilibrium(LE) tool that was used for the support design and analysis of a multi-faceted overhanging rock slope. The overhanging slopes required complex geometries with constantly changing orientations. The overhanging rock varied in height from 30 m to 66 m. Geomechanical modelling combined with discrete fracture network(DFN)representation of the rock mass was used to validate the rock mass strength assumptions and the failure mechanism assumed in the LE model. The advantage of the simplified LE method is that buttress and support design iterations(along with sensitivity analysis of design parameters) can be completed for various cross-sections along the proposed overhanging rock sections in an efficient manner, compared to the more time-intensive, sophisticated methods that were used for the initial validation. The method described presents the development of this design tool and assumptions made for a specific overhanging rock slope design. Other locations will have different geological conditions that can control the potential behaviour of rock slopes, however, the approach presented can be applied as a general guiding design principle for overhanging rock cut slope.
基金This research was financially supported by the grants from the National Natural Science Foundation of China （No. 31071262） and the Shandong Science and Technology Department （No. 032050102）.
文摘C-type lysozyme genes （Lyzls） belong to the class of lysozymes and are highly expressed in the testis and epididymis. The members Lyzl4 and Spaca3 have been reported to play a role in sperm-egg binding and fertilisation in mice. However, the function of the remaining two mouse c-type lysozyme genes, Lyzll and Lyzl6, is still not clear. In the present study, we analysed the tissue expression and androgen-dependent expression of mouse c-type lysozyme genes and the possible contribution of human recombinant LYZL6 （rLYZL6） to immunity. The expression of Lyzlswas detected by RT-PCR, Western blots, immunohistochemistry and immunofluorescence. The bacteriolytic activity of rLYZL6 was analysed by a colony-forming assay. In mice, the expression of Lyzlgenes was mainly in the testis and epididymis in a developmentally regulated manner and androgen- or testicular factor-regulated manner. Immunodetection revealed the presence of LYZL6 protein in primary spermatocytes and round spermatids of the testis and on the post-acrosomal area and midpiece of mature epididymal spermatozoa. The rLYZL6 protein exhibited antibacterial activity. From the results, Lyzls may play a role in mitochondrial function of spermatozoa and LYZL6 may contribute to the innate immunity of the male genital tract.
基金CEFIC LRI,Natural Science Foundation of Jiangsu Province(No.BK20130186)the Fundamental Research Funds for the Central Universities(No.2013QNA18)for funding this project
文摘Novel applications of nanotechnology may lead to the release of engineered nanoparticles（ENPs）, which result in concerns over their potential environmental hazardous impact. It is essential for the research workers to be able to quantitatively characterise ENPs in the environment and subsequently to assist the risk assessment of the ENPs. This study hence explored the application of nanoparticle tracking system（NTA） to quantitatively describe the behaviour of the ENPs in natural sediment-water systems. The NTA allows the measurement of both particle number concentration（PNC） and particle size distribution（PSD） of the ENPs. The developed NTA method was applied to a range of gold and magnetite ENPs with a selection of surface properties. The results showed that the positively-charged ENPs interacted more strongly with the sediment than neutral and negatively-charged ENPs. It was also found that the citrate coated Au ENPs had a higher distribution percentage（53%） than 11-mercaptoundecanoic acid coated Au ENPs（20%） and citrate coated magnetite ENPs（21%）. The principles of the electrostatic interactions between hard（and soft） acids and bases（HSAB） are used to explain such behaviours; the hard base coating（i.e. citrate ions） will interact more strongly with hard acid（i.e. magnetite） than soft acid（i.e. gold）.The results indicate that NTA is a complementary method to existing approaches to characterise the fate and behaviour of ENPs in natural sediment.
基金the financial support from the Jiangsu Specially-Appointed Professors Program and the European Commission under the Marie Skłodowska-Curie Individual Fellowship(H2020-MSCA-IFNTPleasure-748196).
文摘C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)activated heterogeneous catalysis offers a number of advantages,such as relatively mild reaction conditions and energy efficiency,in comparison to the conventional thermal catalysis.This review presents the state-of-the-art for the application of NTP-catalysis towards C1 chemistry,including the CO2 hydrogenation,reforming of CH4 and CH3OH,and water-gas shift(WGS)reaction.In the hybrid NTP-catalyst system,the plasma-catalyst interactions aremultifaceted.Accordingly,this reviewalso includes a brief discussion on the fundamental research into themechanisms of NTP activated catalytic C1 chemistry,such as the advanced characterisation methods(e.g.,in situ diffuse reflectance infrared Fourier transform spectroscopy,DRIFTS),temperatureprogrammed plasma surface reaction(TPPSR),kinetic studies.Finally,prospects for the future research on the development of tailor-made catalysts for NTP-catalysis systems(which will enable the further understanding of its mechanism)and the translation of the hybrid technique to practical applications of catalytic C1 chemistry are discussed.
文摘The. objectives.of this study are to convert at laboratory s.cale agric.ultural residues into activated carbons （AC） with specific properties, to characterize them and to test them in adsorption reactor for tetracycline removal, a common antibiotic. Two new ACs were produced by direct activation with steam from beet pulp （BP-H2O） and peanut hu_lls （PH-H2O） in environmental friendly conditions BP-H2O and PH-H2Opresentcarbon content rangedcarbons with different intrinsic properties.
基金supported by European Union Seventh Framework Programme(FP7/2007-2013)(No.81063)
文摘Flexible strip supercapacitors are developed and their electrochemical properties are characterized. Activated carbon is used as the electrode material and it is found to have a good porous structure which provides a large surface area for energy storage.Furthermore, this activated carbon performs well. The manufacturing processes for the supercapacitors are described in detail and the preparation process has good reproducibility. The strip supercapacitors are combined in series and parallel to measure their electrical properties. The performances of these two samples in series or in parallel both follow the theoretical models. The electrochemical potential window of a series circuit of these two strip supercapacitors is 4.8 V. The energy and power of the series or parallel circuits are equal to the sums of the two strip supercapacitors.
文摘The feasibility of durian tree sawdust (DTS), coconut coir (CC) and oil palm empty fruit bunch (EFB) as low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. The effects of solution pH and initial metal concentration on adsorption capacity were examined in batch experiments. The affinity and the adsorption capacity of DTS, CC and EFB were evaluated. The adsorption behaviour of Cu(II), Pb(II) and Zn(II) ions onto DTS, CC and EFB was described using Freundlich and Langmuir isotherm models. The separation factor (RL) analysis suggests that the removal of metal ions onto three agricultural wastes studied was favourable. The maximum adsorption capacities (Q) estimated from the Langmuir isotherm model for Cu(II), Pb(II) and Zn(II) were 18.42, 20.37 and 22.78 mg/g for DTS, 18.38, 37.04 and 24.39 mg/g for CC, and 26.95, 37.59 and 21.19 mg/g for EFB, respectively. The characterisation studies were carried out using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDX) and Fourier Transform Infrared Spectrometer (FTIR). The surface morphology of the biosorbents changed significantly following interaction with metal ions. The primary adsorption mechanism was complexation between metal ions and binding sites of biosorbents. Both hydroxyl and amine groups are the main binding sites in DTS, CC and EFB.
文摘The development of a pseudo-one pot synthesis of 3（5）,4-dinitropyrazole enabled us to use it as a starting material for energetic plasticisers. Its acidic proton allowed simple derivatisation on one of the ring nitrogens. The thermal characteristics of two derivatives were evaluated. For instance, the N-allyl compound was a liquid with very low glass transition temperature, whereas the N-propargyl compound was a sticky solid at ambient temperature. The two compounds were both thermally stable according to STANAG 4582.
基金financially supported by University Grants Commission,Government of India
文摘This study is done with the aim to bring together the various antimicrobial peptides that are present in the crustacean hemolymph and their sources along with its characteristics.Invertebrates lack immune systems that involve antigen-antibody reactions and do not have an immune memory, therefore most invertebrate species show no evidence of acquired immunity.Crustaceans possess an open circulatory system, where nutrients, oxygen, hormones, and cells are distributed in the hemolymph. They lack adaptive immune system and rely exclusively on their innate immune mechanisms that include both cellular and humoral responses. Antimicrobial peptides and proteins form an important means of host defense in eukaryotes. In addition to their role as endogenous antibiotics, antimicrobial peptides have functions in inflammation,wound repair and regulation of the adaptive immune system. Over the past several years, many antimicrobial peptides have been found and characterized in crabs.
文摘The efficacy of coconut tree sawdust (CTS), eggshell (ES) and sugarcane bagasse (SB) as alternative low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. Batch adsorption studies were carried out to evaluate the effects of solution pH and initial metal concentration on adsorption capacity. The optimum biosorption condition was found at pH 6.0, 0.1 g biomass dosage and at 90 min equilibrium time. The adsorption data were fitted to the Freundlich and Langmuir isotherm models. The adsorption capacity and affinity of CTS, ES and SB were evaluated. The Freundlich constant (n) and separation factor (RL) values suggest that the metal ions were favourably adsorbed onto biosorbents. The maximum adsorption capacities (Q) estimated from the Langmuir isotherm model for Cu(II), Pb(II) and Zn(II) were 3.89, 25.00 and 23.81 mg/g for CTS, 34.48, 90.90 and 35.71 mg/g for ES, and 3.65, 21.28 and 40.00 mg/g for SB, respectively. The characterisation studies were performed using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDX) and Fourier Transform Infrared Spectrometer (FTIR). Interaction with metal ions led to the formation of discrete aggregates on the biosorbents surface. The metal ions bound to the active sites of the biosorbents through either electrostatic attraction or complexation mechanism.
基金Flinders University through the DVCR Research Investment Fund Scheme to provide Research Support for ECR to MCR Academics.
文摘Nanocomposite hydrogels are the combination of known components that are a hydrogel and nanometre-sized fillers,typically leading to improved mechanical properties or new functionalities.With simplicity of design and ease of synthesis,recent advances have highlighted that this family of hydrogels holds the significant promise of application in diverse biomedical and engineering fields.The elaborate design and investigation as well as suitable application of nanocomposite hydrogels require the synergy of mechanics,materials science,engineering,and biology.Despite similarities in design and fabrication,the data of mechanical properties for nanocomposite hydrogels scatter in a large space.It is worthwhile comparing various nanocomposite hydrogels for similarities and differences in mechanical properties to aid in designing novel hydrogels with extreme properties,and guide practical applications.This review aims to fill,in the literature,the missing gap of addressing mechanical measurement methods and comparison of mechanical properties in this ever-evolving broad area of research.Finally,the challenges and future research opportunities are highlighted.
基金the support of the Diamond Light Source for providing the beamtime(MG22506)at the I12 beamlinethe support from the Royal Society International Exchange Grant(IECNSFC191319)and Research Grant(RGSR2202122)。
文摘Isotropy in microstructure and mechanical properties remains a challenge for laser powder bed fusion(LPBF)processed materials due to the epitaxial growth and rapid cooling in LPBF.In this study,a high-strength TiB_(2)/Al-Cu composite with random texture was successfully fabricated by laser powder bed fusion(LPBF)using pre-doped TiB_(2)/Al-Cu composite powder.A series of advanced characterisation techniques,including synchrotron X-ray tomography,correlative focussed ion beam-scanning electron microscopy(FIB-SEM),scanning transmission electron microscopy(STEM),and synchrotron in situ X-ray diffraction,were applied to investigate the defects and microstructure of the as-fabricated TiB_(2)/Al-Cu composite across multiple length scales.The study showed ultra-fine grains with an average grain size of about 0.86μm,and a random texture was formed in the as-fabricated condition due to rapid solidification and the TiB_(2)particles promoting heterogeneous nucleation.The yield strength and total elongation of the as-fabricated composite were 317 MPa and 10%,respectively.The contributions of fine grains,solid solutions,dislocations,particles,and Guinier-Preston(GP)zones were calculated.Failure was found to be initiated from the largest lack-of-fusion pore,as revealed by in situ synchrotron tomography during tensile loading.In situ synchrotron diffraction was used to characterise the lattice strain evolution during tensile loading,providing important data for the development of crystal-plasticity models.
文摘Thermal plasma technology provides a stable and long term treatment of mixed wastes through vitrification processes. In this work, a transferred plasma system was realized to vitrify mixed wastes, taking advantage of its high power density, enthalpy and chemical reactivity as well as its rapid quenching and high operation temperatures. To characterize the plasma discharge, a temperature diagnostic is realized by means of optical emission spectroscopy （OES）. To typify the morphological structure of the wastes samples~ scan- ning electron microscopy （SEM）, and X-ray diffraction （XRD） techniques were applied before and after the plasma treatment.
基金Supported by Huaiyin Institute of Technology Young Talent Project of Science Foundation(HGQN0707)
文摘This thesis gives overview of the connotation of rural spatial structure,indicating 4 kinds of elements,namely nodus,passage,region and flow.Their spatial arrangement and interaction lead to the corresponding rural spatial structure.This thesis also offers panorama of the related theoretical progress of intra-county and rural areas,indicating that the research theories of regional spatial structure at present,mainly focus on macroscopic region or urban space,but there is shortage of researches on county spatial structure,especially microscopic rural spatial structure.On such basis,4 kinds of theoretical models and characteristics of regional spatial structure have been introduced.We build analysis index system of rural structural elements on the basis of 4 elements,and conduct rural spatial structural analysis,taking Jinhu County as an example.The result shows that rural spatial structure in Jinhu County is still at stage of nucleus-cluster development and rural system is not so sound.In addition,the passage network system of infrastructure has not taken shape,and county economy presents diseconomy of scale.The spatial interaction and association among towns in Jinhu County are weak.The characteristic analysis model of spatial structure in this research can objectively reflect regional characteristic of spatial structure.
