In this theoretical study,we investigate the generation of second harmonics(SH)during the interaction of a laser beam with a metallic nanoparticle(MNP)trimer.Utilizing a classical electrodynamics framework,we explore ...In this theoretical study,we investigate the generation of second harmonics(SH)during the interaction of a laser beam with a metallic nanoparticle(MNP)trimer.Utilizing a classical electrodynamics framework,we explore the nonlinear interactions between the laser beam fields and nanoparticles(NPs),accounting for dipole-dipole interactions among the particles.Analytical expressions are derived to quantify the impact of these interactions on SH radiation power for two distinct polarizations of the laser beam.Our findings indicate that when the laser electric field is aligned parallel to the trimer's symmetry axis,there is a significant enhancement in SH radiation power compared to a single non-interacting NP,accompanied by a red-shift in the plasmon resonance peak.Conversely,when the laser electric field is perpendicular to the trimer axis,the SH radiation power from each NP decreases,and the plasmon resonance peak experiences a blue-shift.Additionally,we examine the influence of particle size and interparticle separation on SH generation.These results provide valuable insights into the role of interparticle interactions in enhancing nonlinear optical processes in NP assemblies,with potential implications for the design of nanophotonic devices.展开更多
This study investigates the dromion structure within the context of(2+1)-dimensional modulated positron-acoustic waves in a magnetoplasma consisting of inertial cold positrons and inertialess nonthermal hot electrons ...This study investigates the dromion structure within the context of(2+1)-dimensional modulated positron-acoustic waves in a magnetoplasma consisting of inertial cold positrons and inertialess nonthermal hot electrons and positrons as well as stationary positive ions.The reductive perturbation approach reduces the fluid governing equations to the plasma model to a Davey–Stewartson system.This study provides a detailed analysis of the influence of many related plasma parameters,including the density ratio of hot and cold positrons,the external magnetic field strength,the nonthermal parameter and the density ratio of electrons and cold positrons,on the growing rate of instability.Using the Hirota Bilinear method,it is found that the system supports some exact solutions,such as one-and two-dromion solutions.The change of plasma parameters significantly enhances the characteristics of dromion solutions.The elastic and inelastic collisions between two dromions are discussed at different times.The relevance of this study can help us to understand the various types of collision between energetic particles in confined plasma during the production of energy by thermonuclear fusion.展开更多
Structures modelled with flexible-base assumptions,incorporating soil effects,generally exhibit longer natural periods and higher damping compared to fixed-base models that exclude soil-structure interaction(SSI).Howe...Structures modelled with flexible-base assumptions,incorporating soil effects,generally exhibit longer natural periods and higher damping compared to fixed-base models that exclude soil-structure interaction(SSI).However,the beneficial or detrimental nature of SSI remains contentious in current earthquake damage analyses and research findings.This study introduces a numerical modelling technique,validated by experimental shaking table tests,to examine the effects of SSI on high-rise buildings.The study considers various substructure parameters,including foundation types,soil types,and bedrock depths.Both advantageous and adverse impacts of SSI are identified and analysed.Numerical simulations reveal that increased subsoil stiffness significantly amplifies the base shear of structures compared to bedrock depth effects.Additionally,increased foundation rocking results in higher inter-storey drifts and reduced base shear.Overall,SSI tends to amplify inter-storey drifts,indicating detrimental effects.Specifically,the study found that the inclusion of SSI increased maximum inter-storey drifts by up to 38%,particularly in softer soils,while reducing base shear by up to 44%in structures with classical compensated foundations on D_(e)and E_(e)soil types.In contrast,piled foundation systems experienced an increase in base shear of up to 27%under the same conditions.Conversely,SSI has beneficial impacts on base shear for structures with classical compensated foundations on soil types of D_(e)and E_(e),as it reduces the base shear.For structures with piled foundations and those with classical compensated foundations on C_(e)soil,SSI effects are detrimental.C_(e),D_(e),and E_(e)soils correspond to geotechnical classifications per AS1170,representing stiff,medium,and soft soils respectively.The study also presents minimum base shear ratios considering SSI reduction effects for various foundation types.展开更多
BACKGROUND Thyroid nodules(TN)are increasingly diagnosed worldwide;investigating the association between TN and colon polyps could be helpful in early detection and management.To our knowledge no meta-analysis has ass...BACKGROUND Thyroid nodules(TN)are increasingly diagnosed worldwide;investigating the association between TN and colon polyps could be helpful in early detection and management.To our knowledge no meta-analysis has assessed the relationship between TN and adenomatous colonic polyps.AIM To assess the association between adenomatous colonic polyps,thyroid-stimulating hormone,and TN.METHODS We searched PubMed,MEDLINE,Cochrane Library,EBSCO,and the first 100 articles in Google for articles published in English from inception until April 2025.We included prospective cohorts,retrospective studies,case-control studies,and cross-sectional studies.The keywords thyroid nodules,adenomatous colon polyps,thyroid volume,metabolic syndrome,insulin resistance,and thyroid malignancy were used.RESULTS Out of 237 articles,25 full texts were reviewed,and 5 full texts were included in the final meta-analysis.No relationship was found between TN,colonic polyps,and thyroid-stimulating hormone levels[odd ratio(OR):1.78,95%confidence interval(CI):0.55-5.74,P=0.33].Colonic polyps were more common among patients with TN when addressing heterogeneity(OR:0.42,95%CI:0.30-0.52,P<0.001 and OR:0.08,95%CI:0.70-0.86,P=0.85).CONCLUSION TN were similar among patients with and without adenomatous colonic polyps.However,TN was more common among colon polyps when addressing the heterogeneity.Thyroid-stimulating hormone was not different between those with and without TN.Age,sex,adiposity,and smoking effects might explain the higher rate observed by the included studies.Further studies controlling for the same are needed.展开更多
Machine learning(ML)has emerged as a powerful tool for predicting polymer properties,including glass transition temperature(Tg),which is a critical factor influencing polymer applications.In this study,a dataset of po...Machine learning(ML)has emerged as a powerful tool for predicting polymer properties,including glass transition temperature(Tg),which is a critical factor influencing polymer applications.In this study,a dataset of polymer structures and their Tg values were created and represented as adjacency matrices based on molecular graph theory.Four key structural descriptors,flexibility,side chain occupancy length,polarity,and hydrogen bonding capacity,were extracted and used as inputs for ML models:Extra Trees(ET),Random Forest(RF),Gaussian Process Regression(GPR),and Gradient Boosting(GB).Among these,ET and GPR achieved the highest predictive performance,with R2 values of 0.97,and mean absolute errors(MAE)of approximately 7–7.5 K.The use of these extracted features significantly improved the prediction accuracy compared to previous studies.Feature importance analysis revealed that flexibility had the strongest influence on Tg,followed by side-chain occupancy length,hydrogen bonding,and polarity.This work demonstrates the potential of data-driven approaches in polymer science,providing a fast and reliable method for Tg prediction that does not require experimental inputs.展开更多
Context:In irrigated agriculture,the salt stress is a major problem due to accumulation of salt from the irrigation water in the soil layers.Objectives:The aim of this study is to determinate the effect of salinity on...Context:In irrigated agriculture,the salt stress is a major problem due to accumulation of salt from the irrigation water in the soil layers.Objectives:The aim of this study is to determinate the effect of salinity on some agromorphological traits and seed nutritional quality of three sesames(Sesamum indicum L.)varieties.Methodology:This is how four solutions of different NaCl concentrations from 0,60,120 to 240 mM were used to water sesame plants at the five-leaves stage and this for two months in completely randomized device with four repetitions.Results:The results show a negative effect of the salinity growth and yield parameters,mineral elements,ascorbic acid(to 21.4% in White cultivar,28% in Brown and 24.2% in Black cultivar from 0 to 240 mM NaCl),oil(to 22.6%in White cultivar,32% in Brown and 25.5% in Black cultivar from 0 to 240 mM NaCl)and accumulation of Na(Sodium)content(to 11.8% in White cultivar,15.3% in Brown and 12.2% in Black cultivar from 0 to 240 mM NaCl),osmolytes as proteins(to 14.5% in White cultivar,11.5% in Brown and 9.6%in Black cultivar from 0 to 240 mM NaCl)and antioxydants components.Varieties White and Brown were less affected by salinity.Conclusion:White variety exhibited higher adaptive potential under salinity stress when compared to Brown variety(rich in fiber)and closely followed by Black variety.Thus White variety could be recommended for consumer oil,minerals and proteins.As for Black variety,it could be used,as glucid and antioxydants additives in food.展开更多
The aim of this research is to assess the energy potential of cow dung and corn cob inputs,with a view to estimating their biogas potential.The inputs were characterized in the microbiology laboratory of the National ...The aim of this research is to assess the energy potential of cow dung and corn cob inputs,with a view to estimating their biogas potential.The inputs were characterized in the microbiology laboratory of the National Control Office Quality in Matoto,Conakry.The experiment to produce methane from cow dung and maize cob was carried out at the Applied Research in Natural Sciences Laboratory of the University of Kindia(UK)using the following equipment:Three digesters were each connected to an air chamber(gasometer)by means of flexible pipes 8 mm in diameter,connected by clamps,liquid adhesives,valves and Teflon.This research focused on determining the quantity of biogas contained in each type of substrate(cow dung,maize cob and their mixture).Three experiments on the methanization of these inputs were carried out,with anaerobic digestion lasting 27 days,in a temperature range of 27℃ to 31℃(mesophilic range).The results were as follows:maize cob 28.4 L,cow dung 22.6 L and codigestion 38.7 L.These results compared with similar studies revealed a coincidence.展开更多
BACKGROUND Congenital scoliosis(CS)is a spinal deformity caused by defective segmentation and development of vertebrae during early embryogenesis.It occurs in 0.5%-1%in 1000 births and may rarely occur with congenital...BACKGROUND Congenital scoliosis(CS)is a spinal deformity caused by defective segmentation and development of vertebrae during early embryogenesis.It occurs in 0.5%-1%in 1000 births and may rarely occur with congenital defects affecting the heart or genitourinary system.Truncus arteriosus(TA)is a life-threatening cardiac defect in which a single arterial trunk supplies both systemic and pulmonary circulation,leading to complications such as pulmonary hypertension,heart failure,and severe hypoxia.Although rare individually,the co-occurrence of both conditions poses unique diagnostic and therapeutic challenges,with limited documentation in medical literature.CASE SUMMARY We present a 36-week preterm neonate with CS associated with TA type 1,pre-senting with respiratory distress,cyanosis,and altered spinal curvature.This case demonstrates the complexity of managing neonates with multiple congenital de-fects.Here,the patient was managed with oxygen supplementation,heart failure medication,nasogastric feeding,and multidisciplinary care to optimize her for surgical corrections.A coordinated,interdisciplinary approach was employed to optimize outcomes,particularly in a resource-limited setting.Immediate re-spiratory and cardiovascular stabilization and long-term orthopedic and cardiac interventions were central to improving the patient’s quality of life and survival.CONCLUSION Recognizing co-existing congenital anomalies and their embryological interre-lation is critical in holistic patient care,particularly during neonatal and infancy.展开更多
Acorn production in oaks(Quercus spp.)shows considerable inter-annual variation,known as masting.The effects of pollen sourced from trees within or outside the stand on acorn production were investigated in pedunculat...Acorn production in oaks(Quercus spp.)shows considerable inter-annual variation,known as masting.The effects of pollen sourced from trees within or outside the stand on acorn production were investigated in pedunculate oak(Quercus robur L.)in an ancient mixed woodland during two moderate masting years.Comparisons were made between natural pollination,hand pollinations with out-of-stand pollen,in-stand pollen or a 1:1 combination of the two pollen sources,and for bagged flowers left unpollinated.After all treatments,>85%of the flowers or developing acorns were aborted between May and August of both years.When flowers were protected with pollen bags and no pollen added,no acorns were produced.In contrast,hand pollination with out-of-stand pollen produced the most acorns both years and significantly more than within-stand pollen or natural pollination in 2022.Hand pollination with out-of-stand or within-stand pollen provided significantly more acorns than natural pollination in 2023.In 2022,hand pollination with a 1:1 mixture of out-of-stand and within-stand pollen yielded an intermediate number of mature acorns between those for the out-of-stand and within-stand pollination treatments.The study provides clear evidence of maternal choice during acorn development in pedunculate oak and of the benefits of pollen supplementation.It also confirms that pedunculate oak is a fruit-maturation masting species;abortion of pollinated flowers and immature acorns determines a mast year(rather than the number of flowers produced)at this site.展开更多
We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Trans...We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Transiting Exoplanet Survey Satellite(TESS).The derived radial velocity curve is based on 17 spectra obtained between 2021and 2023,covering all orbital phases of this binary system.The orbital period determined from TESS data,P=27.019803±0.000003 days,agrees within uncertainties with the period established in previous studies.The model constructed for the TESS photometric light curve achieves a precision of 0.01%.The effective temperatures of both components,as well as the system metallicity,were directly derived from the spectra and are Teff,A=6250±50 K,Teff,B=5855±50 K,and[Fe/H]=-0.10±0.08,respectively.Our analysis of the photometric and spectroscopic data allowed us to directly compute the luminosities of the components,LA=1.82 L☉and LB=1.07 L☉,their radii,RA=1.15 R☉and RB=1.00 R☉,and their masses,MA=1.137 M☉and MB=1.023 M☉,with uncertainties below 1%.Comparison with evolutionary tracks indicates that the system’s age is 1.18±0.10 Gyr,and both components are still on the main sequence.The V454 Aur system is particularly interesting due to the partial eclipse of the primary component,which results in the“inversion”of the primary and secondary minima in the photometric light curve.展开更多
We present a wideband polarization analysis of the mode-changing pulsar PSR J1938+2213 using the ultra-wideband low-frequency receiver on Murriyang,the Parkes 64 m radio telescope.Polarization profiles for both the bu...We present a wideband polarization analysis of the mode-changing pulsar PSR J1938+2213 using the ultra-wideband low-frequency receiver on Murriyang,the Parkes 64 m radio telescope.Polarization profiles for both the burst and weak emission modes are obtained.We find that the pulse widths of the two modes exhibit distinct frequency dependencies:the pulse width increases with frequency in the burst mode,but decreases in the weak mode.The linear and circular polarization fractions also show different trends with frequency between the two modes.Our spectral analysis shows that both modes follow power-law spectra,but with differing spectral indices.展开更多
BACKGROUND Since non-alcoholic fatty liver disease(NAFLD)is associated with abnormal liver function tests,treatment recommendations aim to reduce the level of known markers of liver inflammation,such as alanine transa...BACKGROUND Since non-alcoholic fatty liver disease(NAFLD)is associated with abnormal liver function tests,treatment recommendations aim to reduce the level of known markers of liver inflammation,such as alanine transaminase(ALT),aspartate transaminase(AST)and gamma-glutamyl transferase(GGT).Essential phospholipids(EPLs)have been shown to reduce levels of these liver enzymes and improve ultrasonographic features.While non-invasive diagnostic tests have been developed to stage inflammation,these tests were not specifically designed to evaluate patients with NAFLD.This highlights the need to describe the liver enzyme profile across the different levels of NAFLD severity for improved grading and staging of NAFLD.AIM To describe liver enzyme profiles across NAFLD severity to inform a diagnostic staging algorithm and identify who may benefit from EPLs.METHODS This post-hoc analysis of the observational MANPOWER study included 2843 adult patients with newly diagnosed NAFLD.The primary endpoint was assessment of baseline liver enzyme profiles.Secondary endpoints were effectiveness of Essentiale®(an EPL)on liver enzyme levels and ultrasonography findings across three definitions of NAFLD:(1)Statistical distribution of liver enzyme levels;(2)MANPOWER cut-offs;and(3)Presence of physiciandiagnosed non-alcoholic steatohepatitis.The best performing algorithm was used to describe the risk factors and profiles associated with increased liver enzyme levels.RESULTS Of the 2843 patients included in this post-hoc analysis,most were female(62.2%),with a mean age of 48.4 years(SD 8.59 years).Overall,mean levels of ALT,AST and GGT increased with NAFLD severity for all three subgroups,with the rate of chronic comorbidities correlated with NAFLD severity.Across each subgroup of interest,Essentiale significantly reduced average liver enzyme levels and improved ultrasonography features,including diffuse liver hyperechogenicity and heterogeneous liver structure(P<0.05),with greater benefit associated with increased severity.Compared with all algorithms tested,the algorithm based on the statistical distribution of liver enzymes displayed the highest accuracy,sensitivity and specificity for the grading and staging of NAFLD and could form the basis of a diagnostic algorithm.CONCLUSION Liver enzyme profiles may identify NAFLD severity and allow monitoring of therapeutic response.Essentiale may improve liver enzyme levels and ultrasonography features.An algorithm could aid in the diagnosis/staging of NAFLD.展开更多
Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the...Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the treatment of gastrointestinal and respiratory issues along with increasing the platelet count in patients suffering from dengue.In this review paper,the nutritional composition and bioactive compounds of guava leaves,including proteins,vitamins,minerals,and polysaccharides,have been reviewed.The methods of extraction of bioactive compounds from guava leaves and their bioactivities,including antioxidant,anti-diabetic,and anti-cancer potential,have been explored.Further,encapsulation techniques for improving the transport of bioactive compounds and living cells into foods have been studied.The application of guava leaves in different food systems such as herbal tea,pork sausage,chocolates,jelly,meals for chickens,functional beverages,and as antibacterial agents in food preservatives has also been investigated.The findings of this review illustrated that the phytochemicals present in guava leaves showed excellent antimicrobial and antioxidant properties.Encapsulation appears to be a promising technique for improving the stability,bioavailability,and controlled release of bioactive chemicals extracted from guava leaves.Different methods for the encapsulation of bioactive compounds employed and applied in distinct food systems showed preservation of phytochemicals,improved bioactivities,and nutritional values.Overall,this review paper demonstrated how guava leaves,an abundant source of bioactive compounds,can be used as a multipurpose component to create functional foods,edible coatings,and active packaging to enhance the nutritional,antioxidant,and antimicrobial properties of various food systems that have qualities that promote health.展开更多
In this study we theoretically demonstrate ultrahigh-resolution two-dimensional atomic localization within a three-levelλ-type atomic medium via superposition of asymmetric and symmetric standing wave fields.Our anal...In this study we theoretically demonstrate ultrahigh-resolution two-dimensional atomic localization within a three-levelλ-type atomic medium via superposition of asymmetric and symmetric standing wave fields.Our analysis provides an understanding of the precise spatial localization of atomic positions at the atomic level,utilizing advanced theoretical approaches and principles of quantum mechanics.The dynamical behavior of a three-level atomic system is thoroughly analyzed using the density matrix formalism within the realm of quantum mechanics.A theoretical approach is constructed to describe the interaction between the system and external fields,specifically a control field and a probe field.The absorption spectrum of the probe field is thoroughly examined to clarify the spatial localization of the atom within the proposed configuration.A theoretical investigation found that symmetric and asymmetric superposition phenomena significantly influence the localized peaks within a two-dimensional spatial domain.Specifically,the emergence of one and two sharp localized peaks was observed within a one-wavelength domain.We observed notable influences of the intensity of the control field,probe field detuning and decay rates on atomic localization.Ultimately,we have achieved an unprecedented level of ultrahigh resolution and precision in localizing an atom within an area smaller thanλ/35×λ/35.These findings hold promise for potential applications in fields such as Bose-Einstein condensation,nanolithography,laser cooling,trapping of neutral atoms and the measurement of center-of-mass wave functions.展开更多
Integrating the photovoltaic/thermal(PV/T)system in green hydrogen production is an improvement in sustainable energy technologies.In PV/T systems,solar energy is converted into electricity and thermal energy simultan...Integrating the photovoltaic/thermal(PV/T)system in green hydrogen production is an improvement in sustainable energy technologies.In PV/T systems,solar energy is converted into electricity and thermal energy simultaneously using hot water or air together with electricity.This dual use saves a significant amount of energy and officially fights greenhouse gases.Different cooling techniques have been proposed in the literature for improving the overall performance of the PV/T systems;employing different types of agents including nanofluids and phase change materials.Hydrogen is the lightest and most abundant element in the universe and has later turned into a flexible energy carrier for transportation and other industrial applications.Issues,including the processes of Hydrogen manufacturing,preservation as well as some risks act as barriers.This paper provides an analysis of several recent publications on the efficiency of using PV/T technology in the process of green hydrogen production and indicates the potential for its increased efficiency as compared to conventional systems that rely on fossil fuels.Due to the effective integration of solar energy,the PV/T system can play an important role in the reduction of the levelized cost of hydrogen(LCOH)and hence play an important part in reducing the economic calculations of the decarbonized energy system.展开更多
Photodegradation is considered as a universal contributing factor to litter decomposition and carbon(C)cycling within the Earth’s biomes.Identifying how solar radiation modifies the molecular structure of litter is e...Photodegradation is considered as a universal contributing factor to litter decomposition and carbon(C)cycling within the Earth’s biomes.Identifying how solar radiation modifies the molecular structure of litter is essen-tial to understand the mechanism controlling its decom-position and reaction to shifts in climatic conditions and land-use.In this study,we performed a spectral-attenuation experiment following litter decomposition in an understory and gap of a temperate deciduous forest.We found that short-wavelength visible light,especially blue light,was the main factor driving variation in litter molecular struc-ture of Fagus crenata Blume,Quercus crispula Blume,Acer carpinifolium Siebold&Zuccarini and Betula platyphylla Sukaczev,explaining respectively 56.5%,19.4%,66.3%,and 16.7%of variation in its chemical composition.However,the variation also depended on canopy openness:Only in the forest gap was lignin aromatic C negatively associated with C-oxygen(C–O)bonding in polysaccharides receiv-ing treatments containing blue light of the full spectrum of solar radiation.Regardless of species,the decomposition index of litter that explained changes in mass and lignin loss was driven by the relative content of C–O stretching in poly-saccharides and lignin aromatic C.The results suggest that the availability of readily degradable polysaccharides pro-duced by the reduction in lignin aromatic C most plausibly explains the rate of litter photodegradation.Photo-products of photodegradation might augment the C pool destabilized by the input of readily degradable organic compounds(i.e.,polysaccharides).展开更多
The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable...The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable sources,storage,and transport.The challenges,advantages,and uses of H_(2) energy are included at length.Moreover,apart from the sustainable production approaches,the approaches and current developments for combating the carbon dioxide(CO_(2))emissions from existing H_(2) production facilities are highlighted in terms of ca rbon capture,utilization,and storage(CCUS).Concisely,the review discusses current material and recent technological adva ncements in developing pilot projects and large-scale establishments for viable and rapidly emerging sou rce-ba sed H_(2) productio n.Moreover,the review also aims to provide an in-depthdiscussion and explore current developments based on the advantages of H_(2) energy in terms of its utilization,based on its high energy density,and its ability to be used as a feedstock and fuel.On the other hand,the challenges of H_(2) are also elabo rated.Next,the role of CCUS in a carbon-neutral economy and value chain for minimization of emissions from existing facilities is thoroughly deliberated,and the recent commercial-scale implementation of CCUS technologies is highlighted.Extending the utilization and recycling of captured CO_(2) emissions along with H_(2) to produce e-fuels in terms of current advances is detailed in this review.Fu rthermore,the most applicable,efficient,a nd develo ping approaches are discussed for physical and chemical H_(2) storage,considering recent la rge-scale implementations of liquid carriers and liquid organic hydrogen carriers as storage options.Lastly,the review elaborates on recent insights into advances in H_(2) transport infrastructure,including compressed and liquid H_(2) delivery via roads,ships,pipelines,and flight cargo.The review gives precise insights into the recent scenario through an elaborated conclusion of each discussion topic separately and a discussion of future perspectives.The current review will help researchers to fully understand the ongoing research advancements and challenges in the H_(2) value chain for formulating new solutions for sustainable H_(2) production,alo ng with focusing on suitable approaches for its storage and tra nsport to make the production and utilization of H_(2) applicable on a large scale.展开更多
The Marplex Convention was established to prevent the manufacture of unmarked plastic explosives and stipulates that a volatile detection agent must be added at the time of manufacture.However,to-date,laboratory testi...The Marplex Convention was established to prevent the manufacture of unmarked plastic explosives and stipulates that a volatile detection agent must be added at the time of manufacture.However,to-date,laboratory testing remains the internationally accepted practice for identifying and quantifying the taggants stipulated in the Convention.In this project,portable FTIR and Raman instruments were tested for their ability to detect 2,3-dimethyl-2,3-dinitrobutane(DMDNB),the chemical marker incorporated in plastic explosives that are manufactured within Australia.While both FTIR and Raman instruments detected solid DMDNB(98%purity),field analysis of plastic explosives at an Australian Defence establishment showed that both FTIR and Raman spectra were matched the relevant explosive(RDX or PETN),rather than the DMDNB taggant.For all three plastic explosives tested,the concentration of DMDNB was measured by SPME-GC-MS to be between 1.8 and 2%,greater than the minimum 1%concentration stipulated by the Marplex Convention.Additional testing with a plastic explosive analogue confirmed that the minor absorption peaks that would characterize low concentrations of DMDNB were masked by absorption bands from other compounds within the solid.Thus,while both FTIR and Raman spectroscopy are suitable for detection of plastic explosives,neither rely on the presence of DMDNB for detection.It is likely that similar results would be found for other taggants stipulated by the Marplex Convention,given they are also present in concentrations less than 1%.展开更多
文摘In this theoretical study,we investigate the generation of second harmonics(SH)during the interaction of a laser beam with a metallic nanoparticle(MNP)trimer.Utilizing a classical electrodynamics framework,we explore the nonlinear interactions between the laser beam fields and nanoparticles(NPs),accounting for dipole-dipole interactions among the particles.Analytical expressions are derived to quantify the impact of these interactions on SH radiation power for two distinct polarizations of the laser beam.Our findings indicate that when the laser electric field is aligned parallel to the trimer's symmetry axis,there is a significant enhancement in SH radiation power compared to a single non-interacting NP,accompanied by a red-shift in the plasmon resonance peak.Conversely,when the laser electric field is perpendicular to the trimer axis,the SH radiation power from each NP decreases,and the plasmon resonance peak experiences a blue-shift.Additionally,we examine the influence of particle size and interparticle separation on SH generation.These results provide valuable insights into the role of interparticle interactions in enhancing nonlinear optical processes in NP assemblies,with potential implications for the design of nanophotonic devices.
基金The authors extend their appreciation to the Deanship of Scientific Research and Libraries in Princess Nourah bint Abdulrahman University for funding this research work through the Research Group project under Grant No.(RG-1445-0005).
文摘This study investigates the dromion structure within the context of(2+1)-dimensional modulated positron-acoustic waves in a magnetoplasma consisting of inertial cold positrons and inertialess nonthermal hot electrons and positrons as well as stationary positive ions.The reductive perturbation approach reduces the fluid governing equations to the plasma model to a Davey–Stewartson system.This study provides a detailed analysis of the influence of many related plasma parameters,including the density ratio of hot and cold positrons,the external magnetic field strength,the nonthermal parameter and the density ratio of electrons and cold positrons,on the growing rate of instability.Using the Hirota Bilinear method,it is found that the system supports some exact solutions,such as one-and two-dromion solutions.The change of plasma parameters significantly enhances the characteristics of dromion solutions.The elastic and inelastic collisions between two dromions are discussed at different times.The relevance of this study can help us to understand the various types of collision between energetic particles in confined plasma during the production of energy by thermonuclear fusion.
文摘Structures modelled with flexible-base assumptions,incorporating soil effects,generally exhibit longer natural periods and higher damping compared to fixed-base models that exclude soil-structure interaction(SSI).However,the beneficial or detrimental nature of SSI remains contentious in current earthquake damage analyses and research findings.This study introduces a numerical modelling technique,validated by experimental shaking table tests,to examine the effects of SSI on high-rise buildings.The study considers various substructure parameters,including foundation types,soil types,and bedrock depths.Both advantageous and adverse impacts of SSI are identified and analysed.Numerical simulations reveal that increased subsoil stiffness significantly amplifies the base shear of structures compared to bedrock depth effects.Additionally,increased foundation rocking results in higher inter-storey drifts and reduced base shear.Overall,SSI tends to amplify inter-storey drifts,indicating detrimental effects.Specifically,the study found that the inclusion of SSI increased maximum inter-storey drifts by up to 38%,particularly in softer soils,while reducing base shear by up to 44%in structures with classical compensated foundations on D_(e)and E_(e)soil types.In contrast,piled foundation systems experienced an increase in base shear of up to 27%under the same conditions.Conversely,SSI has beneficial impacts on base shear for structures with classical compensated foundations on soil types of D_(e)and E_(e),as it reduces the base shear.For structures with piled foundations and those with classical compensated foundations on C_(e)soil,SSI effects are detrimental.C_(e),D_(e),and E_(e)soils correspond to geotechnical classifications per AS1170,representing stiff,medium,and soft soils respectively.The study also presents minimum base shear ratios considering SSI reduction effects for various foundation types.
文摘BACKGROUND Thyroid nodules(TN)are increasingly diagnosed worldwide;investigating the association between TN and colon polyps could be helpful in early detection and management.To our knowledge no meta-analysis has assessed the relationship between TN and adenomatous colonic polyps.AIM To assess the association between adenomatous colonic polyps,thyroid-stimulating hormone,and TN.METHODS We searched PubMed,MEDLINE,Cochrane Library,EBSCO,and the first 100 articles in Google for articles published in English from inception until April 2025.We included prospective cohorts,retrospective studies,case-control studies,and cross-sectional studies.The keywords thyroid nodules,adenomatous colon polyps,thyroid volume,metabolic syndrome,insulin resistance,and thyroid malignancy were used.RESULTS Out of 237 articles,25 full texts were reviewed,and 5 full texts were included in the final meta-analysis.No relationship was found between TN,colonic polyps,and thyroid-stimulating hormone levels[odd ratio(OR):1.78,95%confidence interval(CI):0.55-5.74,P=0.33].Colonic polyps were more common among patients with TN when addressing heterogeneity(OR:0.42,95%CI:0.30-0.52,P<0.001 and OR:0.08,95%CI:0.70-0.86,P=0.85).CONCLUSION TN were similar among patients with and without adenomatous colonic polyps.However,TN was more common among colon polyps when addressing the heterogeneity.Thyroid-stimulating hormone was not different between those with and without TN.Age,sex,adiposity,and smoking effects might explain the higher rate observed by the included studies.Further studies controlling for the same are needed.
文摘Machine learning(ML)has emerged as a powerful tool for predicting polymer properties,including glass transition temperature(Tg),which is a critical factor influencing polymer applications.In this study,a dataset of polymer structures and their Tg values were created and represented as adjacency matrices based on molecular graph theory.Four key structural descriptors,flexibility,side chain occupancy length,polarity,and hydrogen bonding capacity,were extracted and used as inputs for ML models:Extra Trees(ET),Random Forest(RF),Gaussian Process Regression(GPR),and Gradient Boosting(GB).Among these,ET and GPR achieved the highest predictive performance,with R2 values of 0.97,and mean absolute errors(MAE)of approximately 7–7.5 K.The use of these extracted features significantly improved the prediction accuracy compared to previous studies.Feature importance analysis revealed that flexibility had the strongest influence on Tg,followed by side-chain occupancy length,hydrogen bonding,and polarity.This work demonstrates the potential of data-driven approaches in polymer science,providing a fast and reliable method for Tg prediction that does not require experimental inputs.
文摘Context:In irrigated agriculture,the salt stress is a major problem due to accumulation of salt from the irrigation water in the soil layers.Objectives:The aim of this study is to determinate the effect of salinity on some agromorphological traits and seed nutritional quality of three sesames(Sesamum indicum L.)varieties.Methodology:This is how four solutions of different NaCl concentrations from 0,60,120 to 240 mM were used to water sesame plants at the five-leaves stage and this for two months in completely randomized device with four repetitions.Results:The results show a negative effect of the salinity growth and yield parameters,mineral elements,ascorbic acid(to 21.4% in White cultivar,28% in Brown and 24.2% in Black cultivar from 0 to 240 mM NaCl),oil(to 22.6%in White cultivar,32% in Brown and 25.5% in Black cultivar from 0 to 240 mM NaCl)and accumulation of Na(Sodium)content(to 11.8% in White cultivar,15.3% in Brown and 12.2% in Black cultivar from 0 to 240 mM NaCl),osmolytes as proteins(to 14.5% in White cultivar,11.5% in Brown and 9.6%in Black cultivar from 0 to 240 mM NaCl)and antioxydants components.Varieties White and Brown were less affected by salinity.Conclusion:White variety exhibited higher adaptive potential under salinity stress when compared to Brown variety(rich in fiber)and closely followed by Black variety.Thus White variety could be recommended for consumer oil,minerals and proteins.As for Black variety,it could be used,as glucid and antioxydants additives in food.
文摘The aim of this research is to assess the energy potential of cow dung and corn cob inputs,with a view to estimating their biogas potential.The inputs were characterized in the microbiology laboratory of the National Control Office Quality in Matoto,Conakry.The experiment to produce methane from cow dung and maize cob was carried out at the Applied Research in Natural Sciences Laboratory of the University of Kindia(UK)using the following equipment:Three digesters were each connected to an air chamber(gasometer)by means of flexible pipes 8 mm in diameter,connected by clamps,liquid adhesives,valves and Teflon.This research focused on determining the quantity of biogas contained in each type of substrate(cow dung,maize cob and their mixture).Three experiments on the methanization of these inputs were carried out,with anaerobic digestion lasting 27 days,in a temperature range of 27℃ to 31℃(mesophilic range).The results were as follows:maize cob 28.4 L,cow dung 22.6 L and codigestion 38.7 L.These results compared with similar studies revealed a coincidence.
文摘BACKGROUND Congenital scoliosis(CS)is a spinal deformity caused by defective segmentation and development of vertebrae during early embryogenesis.It occurs in 0.5%-1%in 1000 births and may rarely occur with congenital defects affecting the heart or genitourinary system.Truncus arteriosus(TA)is a life-threatening cardiac defect in which a single arterial trunk supplies both systemic and pulmonary circulation,leading to complications such as pulmonary hypertension,heart failure,and severe hypoxia.Although rare individually,the co-occurrence of both conditions poses unique diagnostic and therapeutic challenges,with limited documentation in medical literature.CASE SUMMARY We present a 36-week preterm neonate with CS associated with TA type 1,pre-senting with respiratory distress,cyanosis,and altered spinal curvature.This case demonstrates the complexity of managing neonates with multiple congenital de-fects.Here,the patient was managed with oxygen supplementation,heart failure medication,nasogastric feeding,and multidisciplinary care to optimize her for surgical corrections.A coordinated,interdisciplinary approach was employed to optimize outcomes,particularly in a resource-limited setting.Immediate re-spiratory and cardiovascular stabilization and long-term orthopedic and cardiac interventions were central to improving the patient’s quality of life and survival.CONCLUSION Recognizing co-existing congenital anomalies and their embryological interre-lation is critical in holistic patient care,particularly during neonatal and infancy.
基金supported by Future Trees TrustThe Patsy Wood Trust+2 种基金Scottish Forestry TrustAitchinson Tait TrustAction Oak
文摘Acorn production in oaks(Quercus spp.)shows considerable inter-annual variation,known as masting.The effects of pollen sourced from trees within or outside the stand on acorn production were investigated in pedunculate oak(Quercus robur L.)in an ancient mixed woodland during two moderate masting years.Comparisons were made between natural pollination,hand pollinations with out-of-stand pollen,in-stand pollen or a 1:1 combination of the two pollen sources,and for bagged flowers left unpollinated.After all treatments,>85%of the flowers or developing acorns were aborted between May and August of both years.When flowers were protected with pollen bags and no pollen added,no acorns were produced.In contrast,hand pollination with out-of-stand pollen produced the most acorns both years and significantly more than within-stand pollen or natural pollination in 2022.Hand pollination with out-of-stand or within-stand pollen provided significantly more acorns than natural pollination in 2023.In 2022,hand pollination with a 1:1 mixture of out-of-stand and within-stand pollen yielded an intermediate number of mature acorns between those for the out-of-stand and within-stand pollination treatments.The study provides clear evidence of maternal choice during acorn development in pedunculate oak and of the benefits of pollen supplementation.It also confirms that pedunculate oak is a fruit-maturation masting species;abortion of pollinated flowers and immature acorns determines a mast year(rather than the number of flowers produced)at this site.
基金support from the National Research Foundation(NRF)of South Africasupported by the Ministry of Science and Higher Education of Russia,topic No.FEUZ-2023-0019。
文摘We present the results of our study of the long-period eclipsing binary star V454 Aur.The results are based on spectroscopic data obtained with the UFESéchelle spectrograph and photometric observations from Transiting Exoplanet Survey Satellite(TESS).The derived radial velocity curve is based on 17 spectra obtained between 2021and 2023,covering all orbital phases of this binary system.The orbital period determined from TESS data,P=27.019803±0.000003 days,agrees within uncertainties with the period established in previous studies.The model constructed for the TESS photometric light curve achieves a precision of 0.01%.The effective temperatures of both components,as well as the system metallicity,were directly derived from the spectra and are Teff,A=6250±50 K,Teff,B=5855±50 K,and[Fe/H]=-0.10±0.08,respectively.Our analysis of the photometric and spectroscopic data allowed us to directly compute the luminosities of the components,LA=1.82 L☉and LB=1.07 L☉,their radii,RA=1.15 R☉and RB=1.00 R☉,and their masses,MA=1.137 M☉and MB=1.023 M☉,with uncertainties below 1%.Comparison with evolutionary tracks indicates that the system’s age is 1.18±0.10 Gyr,and both components are still on the main sequence.The V454 Aur system is particularly interesting due to the partial eclipse of the primary component,which results in the“inversion”of the primary and secondary minima in the photometric light curve.
基金supported by the National Natural Science Foundation of China(Nos.12288102,12203092,12041304,12403060,12203045,12203093,12163001 and 12463007)the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(Nos.2022A03013-3,and 2022A03013-2)+7 种基金the National SKA Program of China(No.2020SKA0120100)the National Key Research and Development Program of China(Nos.2022YFC2205202 and 2021YFC2203502)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Nos.2022D01B71 and 2022D01B218)the Tianshan Talent Training Program for Young Elite Scientists(No.2023TSYCQNTJ0024)the 2022 Project Xinjiang Uygur Autonomous Region of China for Tianchi Talents,the open research project funded by the Key Laboratory of Xinjiang Uyghur Autonomous Region(No.2021000059)the National Key Research and Development Program(No.2022YFA1603104)The research is partly supported by the Operation,Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments,budgeted from the Ministry of Finance of China(MOF)and administrated by the Chinese Academy of Sciences(CAS)Murriyang,CSIRO’s Parkes radio telescope,is part of the Australia Telescope National Facility(https://ror.org/05qajvd42)which is funded by the Australian Government for operation as a National Facility managed by CSIRO.
文摘We present a wideband polarization analysis of the mode-changing pulsar PSR J1938+2213 using the ultra-wideband low-frequency receiver on Murriyang,the Parkes 64 m radio telescope.Polarization profiles for both the burst and weak emission modes are obtained.We find that the pulse widths of the two modes exhibit distinct frequency dependencies:the pulse width increases with frequency in the burst mode,but decreases in the weak mode.The linear and circular polarization fractions also show different trends with frequency between the two modes.Our spectral analysis shows that both modes follow power-law spectra,but with differing spectral indices.
文摘BACKGROUND Since non-alcoholic fatty liver disease(NAFLD)is associated with abnormal liver function tests,treatment recommendations aim to reduce the level of known markers of liver inflammation,such as alanine transaminase(ALT),aspartate transaminase(AST)and gamma-glutamyl transferase(GGT).Essential phospholipids(EPLs)have been shown to reduce levels of these liver enzymes and improve ultrasonographic features.While non-invasive diagnostic tests have been developed to stage inflammation,these tests were not specifically designed to evaluate patients with NAFLD.This highlights the need to describe the liver enzyme profile across the different levels of NAFLD severity for improved grading and staging of NAFLD.AIM To describe liver enzyme profiles across NAFLD severity to inform a diagnostic staging algorithm and identify who may benefit from EPLs.METHODS This post-hoc analysis of the observational MANPOWER study included 2843 adult patients with newly diagnosed NAFLD.The primary endpoint was assessment of baseline liver enzyme profiles.Secondary endpoints were effectiveness of Essentiale®(an EPL)on liver enzyme levels and ultrasonography findings across three definitions of NAFLD:(1)Statistical distribution of liver enzyme levels;(2)MANPOWER cut-offs;and(3)Presence of physiciandiagnosed non-alcoholic steatohepatitis.The best performing algorithm was used to describe the risk factors and profiles associated with increased liver enzyme levels.RESULTS Of the 2843 patients included in this post-hoc analysis,most were female(62.2%),with a mean age of 48.4 years(SD 8.59 years).Overall,mean levels of ALT,AST and GGT increased with NAFLD severity for all three subgroups,with the rate of chronic comorbidities correlated with NAFLD severity.Across each subgroup of interest,Essentiale significantly reduced average liver enzyme levels and improved ultrasonography features,including diffuse liver hyperechogenicity and heterogeneous liver structure(P<0.05),with greater benefit associated with increased severity.Compared with all algorithms tested,the algorithm based on the statistical distribution of liver enzymes displayed the highest accuracy,sensitivity and specificity for the grading and staging of NAFLD and could form the basis of a diagnostic algorithm.CONCLUSION Liver enzyme profiles may identify NAFLD severity and allow monitoring of therapeutic response.Essentiale may improve liver enzyme levels and ultrasonography features.An algorithm could aid in the diagnosis/staging of NAFLD.
文摘Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the treatment of gastrointestinal and respiratory issues along with increasing the platelet count in patients suffering from dengue.In this review paper,the nutritional composition and bioactive compounds of guava leaves,including proteins,vitamins,minerals,and polysaccharides,have been reviewed.The methods of extraction of bioactive compounds from guava leaves and their bioactivities,including antioxidant,anti-diabetic,and anti-cancer potential,have been explored.Further,encapsulation techniques for improving the transport of bioactive compounds and living cells into foods have been studied.The application of guava leaves in different food systems such as herbal tea,pork sausage,chocolates,jelly,meals for chickens,functional beverages,and as antibacterial agents in food preservatives has also been investigated.The findings of this review illustrated that the phytochemicals present in guava leaves showed excellent antimicrobial and antioxidant properties.Encapsulation appears to be a promising technique for improving the stability,bioavailability,and controlled release of bioactive chemicals extracted from guava leaves.Different methods for the encapsulation of bioactive compounds employed and applied in distinct food systems showed preservation of phytochemicals,improved bioactivities,and nutritional values.Overall,this review paper demonstrated how guava leaves,an abundant source of bioactive compounds,can be used as a multipurpose component to create functional foods,edible coatings,and active packaging to enhance the nutritional,antioxidant,and antimicrobial properties of various food systems that have qualities that promote health.
文摘In this study we theoretically demonstrate ultrahigh-resolution two-dimensional atomic localization within a three-levelλ-type atomic medium via superposition of asymmetric and symmetric standing wave fields.Our analysis provides an understanding of the precise spatial localization of atomic positions at the atomic level,utilizing advanced theoretical approaches and principles of quantum mechanics.The dynamical behavior of a three-level atomic system is thoroughly analyzed using the density matrix formalism within the realm of quantum mechanics.A theoretical approach is constructed to describe the interaction between the system and external fields,specifically a control field and a probe field.The absorption spectrum of the probe field is thoroughly examined to clarify the spatial localization of the atom within the proposed configuration.A theoretical investigation found that symmetric and asymmetric superposition phenomena significantly influence the localized peaks within a two-dimensional spatial domain.Specifically,the emergence of one and two sharp localized peaks was observed within a one-wavelength domain.We observed notable influences of the intensity of the control field,probe field detuning and decay rates on atomic localization.Ultimately,we have achieved an unprecedented level of ultrahigh resolution and precision in localizing an atom within an area smaller thanλ/35×λ/35.These findings hold promise for potential applications in fields such as Bose-Einstein condensation,nanolithography,laser cooling,trapping of neutral atoms and the measurement of center-of-mass wave functions.
基金funding support from Arabian Gulf University to cover any necessary publication fees.
文摘Integrating the photovoltaic/thermal(PV/T)system in green hydrogen production is an improvement in sustainable energy technologies.In PV/T systems,solar energy is converted into electricity and thermal energy simultaneously using hot water or air together with electricity.This dual use saves a significant amount of energy and officially fights greenhouse gases.Different cooling techniques have been proposed in the literature for improving the overall performance of the PV/T systems;employing different types of agents including nanofluids and phase change materials.Hydrogen is the lightest and most abundant element in the universe and has later turned into a flexible energy carrier for transportation and other industrial applications.Issues,including the processes of Hydrogen manufacturing,preservation as well as some risks act as barriers.This paper provides an analysis of several recent publications on the efficiency of using PV/T technology in the process of green hydrogen production and indicates the potential for its increased efficiency as compared to conventional systems that rely on fossil fuels.Due to the effective integration of solar energy,the PV/T system can play an important role in the reduction of the levelized cost of hydrogen(LCOH)and hence play an important part in reducing the economic calculations of the decarbonized energy system.
基金supported by the National Natural Science Foundation of China (32122059)the National Key R&D Program of China(2021YFD2200402)+5 种基金the Chinese Academy of Sciences Young Talents Programthe LiaoNing Revitalization Talents Program (XLYC2007016) to QWW2024 Joint Fund Project Funding Program (2023-MSBA-137) to JJDChinese Academy of Sciences President's International Fellowship Initiative (2022VCA0010)the Japan Society for the Promotion of Science (KAKENHI,17F17403) to QWW and HKAcademy of Finland Project(324555) to TMR
文摘Photodegradation is considered as a universal contributing factor to litter decomposition and carbon(C)cycling within the Earth’s biomes.Identifying how solar radiation modifies the molecular structure of litter is essen-tial to understand the mechanism controlling its decom-position and reaction to shifts in climatic conditions and land-use.In this study,we performed a spectral-attenuation experiment following litter decomposition in an understory and gap of a temperate deciduous forest.We found that short-wavelength visible light,especially blue light,was the main factor driving variation in litter molecular struc-ture of Fagus crenata Blume,Quercus crispula Blume,Acer carpinifolium Siebold&Zuccarini and Betula platyphylla Sukaczev,explaining respectively 56.5%,19.4%,66.3%,and 16.7%of variation in its chemical composition.However,the variation also depended on canopy openness:Only in the forest gap was lignin aromatic C negatively associated with C-oxygen(C–O)bonding in polysaccharides receiv-ing treatments containing blue light of the full spectrum of solar radiation.Regardless of species,the decomposition index of litter that explained changes in mass and lignin loss was driven by the relative content of C–O stretching in poly-saccharides and lignin aromatic C.The results suggest that the availability of readily degradable polysaccharides pro-duced by the reduction in lignin aromatic C most plausibly explains the rate of litter photodegradation.Photo-products of photodegradation might augment the C pool destabilized by the input of readily degradable organic compounds(i.e.,polysaccharides).
基金part of a research project PIF Alfa HI initiative 726174Alfaisal University and its Office of Research&Innovation for their continuous support throughout this study。
文摘The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable sources,storage,and transport.The challenges,advantages,and uses of H_(2) energy are included at length.Moreover,apart from the sustainable production approaches,the approaches and current developments for combating the carbon dioxide(CO_(2))emissions from existing H_(2) production facilities are highlighted in terms of ca rbon capture,utilization,and storage(CCUS).Concisely,the review discusses current material and recent technological adva ncements in developing pilot projects and large-scale establishments for viable and rapidly emerging sou rce-ba sed H_(2) productio n.Moreover,the review also aims to provide an in-depthdiscussion and explore current developments based on the advantages of H_(2) energy in terms of its utilization,based on its high energy density,and its ability to be used as a feedstock and fuel.On the other hand,the challenges of H_(2) are also elabo rated.Next,the role of CCUS in a carbon-neutral economy and value chain for minimization of emissions from existing facilities is thoroughly deliberated,and the recent commercial-scale implementation of CCUS technologies is highlighted.Extending the utilization and recycling of captured CO_(2) emissions along with H_(2) to produce e-fuels in terms of current advances is detailed in this review.Fu rthermore,the most applicable,efficient,a nd develo ping approaches are discussed for physical and chemical H_(2) storage,considering recent la rge-scale implementations of liquid carriers and liquid organic hydrogen carriers as storage options.Lastly,the review elaborates on recent insights into advances in H_(2) transport infrastructure,including compressed and liquid H_(2) delivery via roads,ships,pipelines,and flight cargo.The review gives precise insights into the recent scenario through an elaborated conclusion of each discussion topic separately and a discussion of future perspectives.The current review will help researchers to fully understand the ongoing research advancements and challenges in the H_(2) value chain for formulating new solutions for sustainable H_(2) production,alo ng with focusing on suitable approaches for its storage and tra nsport to make the production and utilization of H_(2) applicable on a large scale.
基金funded by the Defence Science Technology Group(DSTG)。
文摘The Marplex Convention was established to prevent the manufacture of unmarked plastic explosives and stipulates that a volatile detection agent must be added at the time of manufacture.However,to-date,laboratory testing remains the internationally accepted practice for identifying and quantifying the taggants stipulated in the Convention.In this project,portable FTIR and Raman instruments were tested for their ability to detect 2,3-dimethyl-2,3-dinitrobutane(DMDNB),the chemical marker incorporated in plastic explosives that are manufactured within Australia.While both FTIR and Raman instruments detected solid DMDNB(98%purity),field analysis of plastic explosives at an Australian Defence establishment showed that both FTIR and Raman spectra were matched the relevant explosive(RDX or PETN),rather than the DMDNB taggant.For all three plastic explosives tested,the concentration of DMDNB was measured by SPME-GC-MS to be between 1.8 and 2%,greater than the minimum 1%concentration stipulated by the Marplex Convention.Additional testing with a plastic explosive analogue confirmed that the minor absorption peaks that would characterize low concentrations of DMDNB were masked by absorption bands from other compounds within the solid.Thus,while both FTIR and Raman spectroscopy are suitable for detection of plastic explosives,neither rely on the presence of DMDNB for detection.It is likely that similar results would be found for other taggants stipulated by the Marplex Convention,given they are also present in concentrations less than 1%.
