Three-dimensional strata movement around coal face of steeply dipping seam group

Steeply dipping seam group,which has complex occurrence conditions,be- longs to the steeply dipping seam.The research on the strata movement around the coal face not only improves safe production technology in practice,but also develops the min- ing theory.By using physical simulation experiments,numerical simulation and site test, the deformation,failure and movement of surrounding rock in longwall working face were analyzed.According to the analysis,characteristics of the seam group were formed which is different from the single seam.Asymmetry mechanics,sequential changes and imbal- ance of strata movement along the tendency working face were summarized.Furthermore the features of upper and lower seams were different.The mining of the lower seam in- duced more complex strata movement along the strike.Multi-section mining disturbed surrounding rocks in larger areas than the single section mining did,which had an impact on and dynamic loading function to the support when mining the lower seam,and pro- duced a great influence on the stability of support-rock system.

Immobilization of Oxyanions on the Reconstructed Heterostructure Evolved from a Bimetallic Oxysulfide for the Promotion of Oxygen Evolution Reaction

Efficient and durable oxygen evolution reaction(OER)requires the electrocatalyst to bear abundant active sites,optimized electronic structure as well as robust component and mechanical stability.Herein,a bimetallic lanthanum-nickel oxysulfide with rich oxygen vacancies based on the La_(2)O_(2)S prototype is fabricated as a binder-free precatalyst for alkaline OER.The combination of advanced in situ and ex situ characterizations with theoretical calculation uncovers the synergistic effect among La,Ni,O,and S species during OER,which assures the adsorption and stabilization of the oxyanion SO_(4)^(2-)onto the surface of the deeply reconstructed porous heterostructure composed of confining Ni OOH nanodomains by La(OH)_3 barrier.Such coupling,confinement,porosity and immobilization enable notable improvement in active site accessibility,phase stability,mass diffusion capability and the intrinsic Gibbs free energy of oxygen-containing intermediates.The optimized electrocatalyst delivers exceptional alkaline OER activity and durability,outperforming most of the Ni-based benchmark OER electrocatalysts.

Risk Assessment of Human Exposure to 2-Methylnaphthalene, Phenanthrene and Didodecylphthalate via Consumption of Shrimps (Macrobrachium vollenhovenii) from Qua Iboe River Estuary, South-South Nigeria

Ibeno, one of the major oil producing communities in South-South Nigeria is a coastal commercial fishery hub that houses Axon-Mobil operational base and pharmaceutical/plastic industries. Shrimp species (Macrobrachium vollenhovenii) is a major aquatic food frequently consumed by inhabitants of the coastal area and those living hinterland, thus, being a major route of human exposure to 2-methylnaphthalene, phenanthrene and didodecyl phthalate in the area. The purpose of the study was to evaluate factors that determine bioaccumulation and assess the potential cancer and non-cancer risk posed by these contaminants through human (adult and children) exposure via shrimp’s consumption using gas chromatography-mass spectroscopy. The associated sediment showed higher mean concentrations of 2-methylnaphthalene, phenanthrene and didodecylphthalate at the two sites relative to those in fresh shrimp samples and factors such as size, lipid content, physicochemical property and environmental condition influenced the uptake of these contaminants. Besides water loss, the traditional drying process enhanced the levels of phenanthrene and didodecylphthalate in dry shrimps most likely due to combustion process and relatively low volatility, respectively and lowered the level of 2-methylnapthalene linked to its relatively high volatility. The potential of cancer and non-cancer development in human were highest via dry large shrimp consumption and followed the sequence: dry small shrimp > fresh large shrimp > fresh small shrimp and were within the USEPA reference standards. Although children were more vulnerable, the exposed individuals may not exhibit notable health-associated adverse effects in the near future. Thus, adequate advocacy is needed to sensitize those living in the catchments who often prefer dry shrimp in their meals on the adverse health implications of these contaminants for their survival and the need to maintain the health of the ecosystem.

某些过渡金属钌配合物非线性光学性能的从头算和密度泛函理论研究

实验发现金属钌的某些配合物具有大的非线性光学性能 .我们的理论研究表明金属钌配合物[Ru(NH3 ) 4LDLA]n + (n =2 ,3;LD,LA=吡啶衍生物配体 )的非线性光学性能取决于推电子基团LD 的给电子能力以及拉电子基团LA 的受电子能力 ,LD 和LA 的推拉电子能力越强越有利于提高配合物的二阶非线性光学系数 β,因此带正电荷的LA 能大幅度提高 β值 .虽然增加共轭体系的长度有利于提高 β值 ,但在Ru的配体中 ,吡啶环间或吡啶环与苯环间不一定要保持共面也会有大的β值 .DFT和abinitio方法的计算结果对比表明 ,对于含过渡金属Ru的化合物 ,在HF水平上难以得到满意的结论 ,由从头算有限场方法计算得到的 β值偏小 ,而用TDDFT方法能得到可与实验值符合较好的结果 .

Pilot-scale Experiment for Purification of CO from Industrial Tail Gases by Pressure Swing Adsorption

用压力，净化从工业气体解除的碳一氧化物(公司) 的秋千吸附(PSA ) 技术是一个高效率、节俭的方法。在这篇文章，为公司纯化的一个四床的 PSA 实验被改进并且优化，在哪个一套 120 m3 路h ? 1 台飞行员规模 PSA 设备被开发从工业尾巴气体净化公司，对工业生产合适的一套控制系统被开发，并且公司纯化上的操作参数的影响被调查。试验性的结果显示飞行员规模 PSA 设备能生产合格产品气体并且在优化条件下面得到高公司恢复比率。研究可以提供可靠基本数据，为公司的工业规模利用，从工业尾巴气体，并且有竞争力量和一个宽广支持的应用程序勘探的强壮的市场。

Ambient nanoparticles/nanominerals and hazardous elements from coal combustion activity:Implications on energy challenges and health hazards

Coal is the most abundant fossil fuel in the world. Because of the growth of coal mining, coal-fired power plants and coal-burning industries, the increase of the emission of particulates(coarse, fine or ultrafine)is of great concern. There is a relationship between increasing human morbidity and mortality and progressive environmental air pollution caused by these types of particles. Thus, the knowledge of the physico-chemical composition and ambient concentrations of coal-derived nanoparticles will improve pollution control strategy. Given the current importance of this area of research, the advanced characterization of this coal combustion-derived nanoparticles/nanominerals as well as hazardous elements is likely to be one of the hottest research fields in coming days. In this review, we try to compile the existing knowledge on coal-derived nanoparticles/nanominerals and discuss the advanced level of characterization techniques for future research. This review also provides some of aspects of health risks associated with exposure to ambient nanoparticles. In addition, the presence of some of the hazardous elements in coal and coal combustion activities is also reviewed.

Instrumental neutron activation analysis of beachrock samples of South East Coast of Tamilnadu,India

Element profiles of some beach rock samples collected from South East Coast of Tamilnadu, India have been determined using single comparator method of INAA. The geo-chemical behavior of the elements in the region is discussed. The irradiations were done at thermal neutron flux of ~ 1011 cm-2·s-1 at 20kW power using Kalpakkam Mini Reactor (KAMINI), IGCAR, Kalpakkam, Tamilnadu, India. Around 19 elements have been determined from 15 samples by high-resolution gamma spectrometry. The accuracy and precision were evaluated by assaying the irradiated Standard Reference Material (SRM 1646a Estuarine sediment) and were found to be in good agreement with certified values.

Burn-Up Measurements on Dissolver Solution of Mixed Oxide Fuel Using HPLC-Mass Spectrometric Method

Burn-up measurement on an irradiated mixed oxide (MOX) test fuel pellet was carried out through measurements on the dissolver solution by HPLC-Thermal Ionization Mass Spectrometric (TIMS) technique. The studies carried out using HPLC as well as TIMS for quantification of burn-up value are described. While in one case, both the separation and determination of elements of interest (U, Pu and Nd) were carried out by HPLC;in another case, TIMS technique was used to quantify them from the HPLC separated fractions.The rapid separation procedures developed in our laboratory earlier were employed to isolate pure fractions of the desired elements. The individual lanthanide fission products (La to Eu) were separated from each other using dynamic ion-exchange chromatographic technique whereas uranium and plutonium were separated from each other using reversed phase chromatographic technique. The pure fractions of U, Pu and Nd obtained after HPLC separation procedure for “spiked” and “unspiked” dissolver solutions were used in TIMS measurements for the first time in our laboratory. In TIMS analysis, isotopic abundances of uranium, plutonium and neodymium fractions obtained from HPLC separation procedure on an “unspiked” fuel sample were measured. For the determination of U, Pu and Nd by isotopic dilution mass spectrometric technique (IDMS), known quantities of tracers enriched in 238U, 240Pu and 142Nd were added to the pre-weighed dissolver solution and subjected to HPLC separation procedures. The isotope ratios viz. 142Nd/(145Nd +146Nd), 238U/233U and 240Pu/239Pu in the pertinent “spiked” fractions were subsequently measured by TIMS. The spikes were pre-standardized in our laboratory employing reverse isotopic dilution technique against the standard solutions available in our laboratory (for 238U, 239Pu and 142Nd, standard solutions of 233U, 239Pu (of higher abundance than in the sample) and 150Nd were employed as spikes). The burn-up values from duplicate spiking experiments were computed based on the summation of 145Nd + 146Nd. The concentrations of neodymium, uranium and plutonium were also measured using HPLC with post-column derivatisation technique using aresenazo(III) as the post-column reagent. The atom % burn-up computed from HPLC and TIMS techniques were in good agreement.

Serum and urine metabolomic fingerprinting in diagnostics of inflammatory bowel diseases

AIM:To evaluate the utility of serum and urine metabolomic analysis in diagnosing and monitoring of inflammatory bowel diseases(IBD).METHODS:Serum and urine samples were collected from 24 patients with ulcerative colitis(UC),19 patients with the Crohn’s disease(CD)and 17 healthy controls.The activity of UC was assessed with the Simple Clinical Colitis Activity Index,while the activity of CD was determined using the Harvey-Bradshaw Index.The analysis of serum and urine samples was performed using proton nuclear magnetic resonance(NMR)spectroscopy.All spectra were exported to Matlab for preprocessing which resulted in two data matrixes for serum and urine.Prior to the chemometric analysis,both data sets were unit variance scaled.The differences in metabolite fingerprints were assessed using partial least-squaresdiscriminant analysis(PLS-DA).Receiver operating characteristic curves and area under curves were used to evaluate the quality and prediction performance of the obtained PLS-DA models.Metabolites responsible for separation in models were tested using STATISTICA10 with the Mann-Whitney-Wilcoxon test and the Student’s t test(α=0.05).RESULTS:The comparison between the group of patients with active IBD and the group with IBD in remission provided good PLS-DA models(P value 0.002for serum and 0.003 for urine).The metabolites that allowed to distinguish these groups were:N-acetylated compounds and phenylalanine(up-regulated in serum),low-density lipoproteins and very low-density lipoproteins(decreased in serum)as well as glycine(increased in urine)and acetoacetate(decreased in urine).The significant differences in metabolomic profiles were also found between the group of patients with active IBD and healthy control subjects providing the PLS-DA models with a very good separation(P value<0.001 for serum and 0.003 for urine).The metabolites that were found to be the strongest biomarkers included in this case:leucine,isoleucine,3-hydroxybutyric acid,N-acetylated compounds,acetoacetate,glycine,phenylalanine and lactate(increased in serum),creatine,dimethyl sulfone,histidine,choline and its derivatives(decreased in serum),as well as citrate,hippurate,trigonelline,taurine,succinate and 2-hydroxyisobutyrate(decreased in urine).No clear separation in PLS-DA models was found between CD and UC patients based on the analysis of serum and urine samples,although one metabolite(formate)in univariate statistical analysis was significantly lower in serum of patients with active CD,and two metabolites(alanine and N-acetylated compounds)were significantly higher in serum of patients with CD when comparing jointly patients in the remission and active phase of the diseases.Contrary to the results obtained from the serum samples,the analysis of urine samples allowed to distinguish patients with IBD in remission from healthy control subjects.The metabolites of importance included in this case up-regulated acetoacetate and down-regulated citrate,hippurate,taurine,succinate,glycine,alanine and formate.CONCLUSION:NMR-based metabolomic fingerprinting of serum and urine has the potential to be a useful tool in distinguishing patients with active IBD from those in remission.

Toxicity and antifeedant activity of essential oils from three aromatic plants grown in Colombia against Euprosterna elaeasa and Acharia fusca(Lepidoptera:Limacodidae)

Objective:To determine the biological effects of essential oils(EOs) isolated from Cymbopogon iiardus,Cymbopogon Jlexuosus and Cvrnbopogon marlinii grown in Colombia against two Lepidoptera larvae,common pests in the oil palm.Methods:Specimens were captured in the field and the antifeedant activity and dermal contact lethality of EOs were measured against Acharia fusca and Euprosterna elaeasa(Lepidoptera:I.imacodidae) at various concentrations 0.002-0.600 μL/cm^3 and 0.002-8 μL/g,respectively.Results:All EOs exhibited strong antifeedant and toxicity activity toward Acharia fusca and Euprosterna elaeasa larvae.Cymbopogon marlinii oil was llie most active againsl both pest insect species,although all tested EOs were better than the synthetic;repellent IR535 on both insects.Conclusions:Colombian EOs have potential for integrated pest management programs in the oil palm industry.

Ultrasonic Plasma Engineering Toward Facile Synthesis of Single-Atom M-N4/N-Doped Carbon(M=Fe,Co) as Superior Oxygen Electrocatalyst in Rechargeable Zinc-Air Batteries

As bifunctional oxygen evolution/reduction electrocatalysts,transition-metal-based single-atom-doped nitrogen-carbon(NC)matrices are promising successors of the corresponding noblemetal-based catalysts,offering the advantages of ultrahigh atom utilization effciency and surface active energy.However,the fabrication of such matrices(e.g.,well-dispersed single-atom-doped M-N4/NCs)often requires numerous steps and tedious processes.Herein,ultrasonic plasma engineering allows direct carbonization in a precursor solution containing metal phthalocyanine and aniline.When combining with the dispersion effect of ultrasonic waves,we successfully fabricated uniform single-atom M-N4(M=Fe,Co)carbon catalysts with a production rate as high as 10 mg min-1.The Co-N4/NC presented a bifunctional potential drop ofΔE=0.79 V,outperforming the benchmark Pt/C-Ru/C catalyst(ΔE=0.88 V)at the same catalyst loading.Theoretical calculations revealed that Co-N4 was the major active site with superior O2 adsorption-desorption mechanisms.In a practical Zn-air battery test,the air electrode coated with Co-N4/NC exhibited a specific capacity(762.8 mAh g(-1))and power density(101.62 mW cm^(-2)),exceeding those of Pt/C-Ru/C(700.8 mAh g^(-1) and 89.16 mW cm^(-2),respectively)at the same catalyst loading.Moreover,for Co-N4/NC,the potential difference increased from 1.16 to 1.47 V after 100 charge-discharge cycles.The proposed innovative and scalable strategy was concluded to be well suited for the fabrication of single-atom-doped carbons as promising bifunctional oxygen evolution/reduction electrocatalysts for metal-air batteries.

Environmental assessment and nano-mineralogical characterization of coal,overburden and sediment from Indian coal mining acid drainage

The deterioration of environmental conditions is the major contributory factor to poor health and quality of life that hinders sustainable development in any region.Coal mining is one of the major industries that contribute to the economy of a country but it also impacts the environment.The chemical parameters of the coal,overburden,soil and sediments along with the coal mine drainage(CMD)were investigated in order to understand the overall environmental impact from high sulphur coal mining at northeastern coalfield(India).It was found that the total sulphur content of the coal is noticeably high compared to the overburden(OB)and soil.The volatile matter of the coal is sufficiently high against the high ash content of the soil and overburden.The water samples have a High Electrical Conductivity(EC)and high Total Dissolve Solid(TDS).Lower values of pH,indicate the dissolution of minerals present in the coal as well as other minerals in the mine rejects/overburden.The chemical and nano-mineralogical composition of coal,soil and overburden samples was studied using a High Resolution-Transmission Electron Microscopy(HR-TEM),Energy Dispersive Spectroscopy(EDS),Selected-Area Diffraction(SAED),Field Emission-Scanning Electron Microscopy(FE-SEM)/EDS,X-ray diffraction(XRD),Fourier Transform Infrared Spectroscopy(FTIR),Raman and Ion-Chromatographic analysis,and Mossbauer spectroscopy.From different geochemical analysis it has been found that the mine water sample from Ledo colliery has the lowest pH value of 3.30,Tirap colliery samples have the highest electrical conductivity value of5.40 ms cm^(-1)Both Ledo and Tirap coals have total sulphur contents within the range 3-3.50%.The coal mine water from Tirap colliery(TW-15 B)has high values of Mg^(2+)(450 ppm),and Br^-(227.17 ppm).XRD analysis revealed the presence of minerals including quartz and hematite in the coals.Mineral analysis of coal mine overburden(OB)indicates the presence both of pyrite and marcasite which was also confirmed in XRD and Mossbauer spectral analysis.The presented data of the minerals and ultra/nano-particles present shows their ability to control the mobility of hazardous elements,suggesting possible use in environmental management technology,including restoration of the delicate Indian coal mine areas.

Analytical Relevance of Trace Metal Speciation in Environmental and Biophysicochemical Systems

This article presents a review of the analytical relevance of trace metal speciation analysis, which must be considered in environmental and biophysicochemical systems for reliable and efficient assessment and monitoring of trace metals. Examples are given of methodological approaches used for speciation analysis. An overview of speciation analysis in sediments, aquatic ecosystems and agrosystems is also presented.

Raman Optical Activity and Raman Spectra of Amphetamine Species--Quantum Chemical Model Calculations and Experiments

Theoretical calculations and preliminary measurements of vibrational Raman optical activity (ROA) spectra of different species of amphetamine (amphetamine and amphetamine-H+) are reported for the first time. The quantum chemical calculations were carried out as hybrid ab initio DFT-molecular orbital calculations by use of the Gaussian 03W program, based on complete geometry minimizations of the conformational energy of the S-(+)-amphetamine molecule, the S-(+)-amphetamine-H+ ion, and the R-(–)-amphetamine molecule. Following this, harmonic frequency calculations have been made, providing information about the cation vibrational bands, expected in salts of single anions (chlorides) as well as in salts of anions with internal bonds (sulfates, hydrogen phosphates, etc.). It shows that the kind of anion should be given better attention, as so far it has often not been the case, when the spectra are employed for identification purposes. The DFT calculations show that the most stable conformations are those allowing for close contact between the aromatic ring and the amine hydrogen atoms. The internal rotational barrier within the same amphetamine enantiomer has a considerable influence on the Raman and ROA spectra. As predicted the experimental ROA spectra were found to depend on the chirality. Two street samples, provided by the London Police, were also measured and compared to the calculated ROA spectra. The street samples were found to contain different enantiomers of the protonated amphetamine-H+ sulfate. According to the present study the AMPH+ ion in aqueous sulfate solution seems to adopt a conformation in which the phenyl and ammonium groups are in transpositions, similar to what has been found in the solid state.

Reaction of Crossed Diperoxidation Between Cyclic Ketones and Alkyl Ketones

The reaction of crossed diperoxidation between the cyclic ketones and the alkyl ketones was investigated. The reaction is a competing in different ketones. It is slightly favorable to resulting in crossed ketone diperoxide and to resulting in crossed cycloketone diperoxide when the cycloketone reacts with the aliphatic ketone.

Influence of Co-Solvent on the Extraction Behaviour of Uranium and Thorium Nitrates with Organophosphorous Compounds

Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.

Recovery of Uranium and Plutonium from Waste Matrices Using Supercritical Fluid Extraction

Supercritical fluid extraction (SFE) of plutonium in its nitrate form from actual waste, i.e. plutonium bearing cellulose matrix was demonstrated using 0.1 litre capacity extraction vessel. Complete recovery of plutonium was demonstrated using modified supercritical carbon dioxide (Sc-CO2), i.e. Sc-CO2 containing octylphenyl-N, N-diisobutyl-carbamoyl- methylphosphine oxide (φCMPO). Near complete recovery of uranium was demonstrated from simulated waste matri- ces, i.e. uranium bearing teflon, glass and cellulose matrices using preparative scale SFE, i.e. from 1 litre capacity ex- traction vessel. The recovery of uranium was established using Sc-CO2 modified with acetyl acetone.