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Wyświetlanie 1-20 z 20
Tytuł:
GAP/DNTF Based PBX Explosives: a Novel Formula Used in Small Sized Explosive Circuits
Autorzy:
An, C.
Wen, X.
Wang, J.
Wu, B.
Powiązania:
https://bibliotekanauki.pl/articles/358581.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
explosive circuits
GAP/DNTF based PBX explosives
thermal stability
mechanical sensitivity
propagation reliability
detonation velocity
Opis:
With 3,4-dinitrofurazanofuroxan (DNTF) and glycidyl azide polymer (GAP) as the main explosive and binder respectively, GAP/DNTF based PBX explosives were designed, prepared and used to fill the small groove of some explosive circuits. The formulation was: DNTF 85 wt.%, GAP 11 wt.%, 2,4-toluene diisocyanate (TDI) and other additives making up the final 4 wt.%. After the uncured slurry mixture was prepared by uniform mixing, a squeezing device was used to charge the circuit groove (dimensions less than 1 mm × 1 mm). Scanning electron microscope (SEM) results showed a fine charging effect. Differential Scanning Calorimetry (DSC) was used to determine the energy of activation (Ea) and the pre-factor (A) of GAP/DNTF and these were compared with those for raw DNTF. The influences and causes of it have been investigated. The experimental results for propagation reliability showed that when the dimensions of the linear groove were 0.8 mm × 0.8 mm, 0.7 mm × 0.7 mm, 0.6 mm × 0.6 mm or 0.5 mm × 0.5 mm, GAP/DNTF based PBX explosives can propagate explosion successfully. Furthermore, the H50 and friction sensitivity of GAP/DNTF based PBX explosives were obtained using the following mechanical sensitivity experiments. These properties are vital if GAP/DNTF based PBX explosives are to be applied in complex explosive circuits.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 2; 397-410
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the rheological properties of CL-20/HTPB casting explosives
Autorzy:
Li, H.-X..
Wang, J-Y.
An, C.-W.
Powiązania:
https://bibliotekanauki.pl/articles/358310.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
casting explosive
particle gradation
rheological properties
plasticizer
Opis:
The rheological properties of ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12hexaazaisowurtzitane (CL-20)/hydroxy-terminated polybutadiene (HTPB) casting explosives with different formulations were tested and analyzed. The effects of both the weight percentage (wt.%) of CL-20 and its particle size, as well as the type and content of plasticizers, on the rheological properties of CL-20/HTPB casting explosives were investigated in detail. The results show that the viscosity and pseudoplasticity of CL-20/HTPB casting explosives increase with increasing wt.% of CL-20 and decreasing particle size. The gradation of CL-20 particle size also affects the rheological properties of the casting explosives. When the mixing ratio of 30 μm to 2 μm particles is 3:1, the viscosity reaches its lowest value and the non-Newtonian index reaches the maximum value of 0.5698. The viscosity, non-Newtonian index and impact sensitivity of the samples studied are clearly decreased by the addition of dioctyl adipate (DOA), dioctyl sebacate (DOS) or dibutyl phthalate (DBP). However, the three plasticizers do not appear to affect the thermal decomposition of CL-20/HTPB casting explosives. With respect to the rheological properties, mechanical properties and sensitivity, DOA is the optimum plasticizer to use in CL-20/HTPB casting explosives.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 2; 237-255
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Insensitive Booster Explosive: DAAF Surface-coated with Viton A
Autorzy:
Li, X.
Wu, B.
Liu, S.
An, C.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/358841.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
DAAF
refinement
surface-coated
thermal analysis
impact sensitivity
Opis:
3,3’-Diamino-4,4’-azoxyfurazan (DAAF) is the principal component of an insensitive booster explosive; refined DAAF and DAAF surface-coated with Viton A were prepared. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were employed to characterize the morphology, composition, and thermal decomposition of these samples. The impact sensitivity and theoretical detonation velocity of DAAF-based composites were also measured and analyzed. The results showed that DAAF surface-coated with Viton A was successfully obtained, and the impact sensitivity of DAAF/Viton A composites was much lower than that of crude DAAF. In addition, DAAF/Viton A composites exhibited better thermal stability compared to crude DAAF and refined DAAF. The theoretical detonation velocity of DAAF/Viton A composites and TATB/Viton A composites are roughly the same. Therefore, there is still great potential for DAAF to be used as the main explosive component of a booster explosive.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 3; 445-455
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Process Optimization and Characterization of an HMX/Viton Nanocomposite
Autorzy:
Shi, X.
Wang, C.
Wang, J.
Li, X.
An, C.
Ji, W.
Powiązania:
https://bibliotekanauki.pl/articles/358667.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HMX
spray drying
processing parameters
optimization
impact sensitivity
nanoparticles
Opis:
HMX/Viton A nanocomposites were prepared by a spray drying process using different processing parameters, which included the dry gas inlet temperature, the air flow rate, and the solution feed flow rate. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the nanocomposites. The effects of the processing parameters on the morphology of the samples were investigated and are discussed. The thermal decomposition behaviour and impact sensitivity of the raw HMX and HMX/Viton A nanocomposites were also measured and compared. Optimal morphology and dispersion of the coated samples was achieved when the dry gas inlet temperature and the air and solution feed flow rates were 55 °C, 660 L/h and 1.5 mL/min, respectively. Under these optimal processing conditions, the nanocomposites were spherical in shape, ranged from 0.2-2 μm in size, and were composed of many tiny particles of 50-100 nm in size. The crystal phase of the nanocomposites was the same as that of raw HMX. Compared with those of raw HMX, the melting point and impact sensitivity of the nanocomposites were lower and the thermal decomposition rate was slightly higher.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 3; 487-495
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of Ultrafine HMX/TATB Explosive Co-crystals
Autorzy:
An, C.
Li, H.
Zhang, Y.
Ye, B.
Xu, C.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/358105.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HMX
TATB
ultrafine co-crystals
ball milling
mechanical sensitivity
Opis:
An explosive co-crystal of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was prepared by the ball milling method. The raw materials and co-crystals were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Raman spectroscopy. Impact and friction sensitivity of the co-crystals were tested and analyzed. The results showed that the HMX/TATB co-crystals are spherical in shape and 100-300 nm in size. The co-crystals are different from anintimate mixture of HMX/TATB and they exhibit a new co-crystal structure. HMX/TATB co-crystals are formed by N-O···H hydrogen bonding between −NO2 (HMX) and −NH2 (TATB). The drop height of ultrafine HMX/TATB explosive co-crystals is 12.7 cm higher than that of ultrafine HMX, whilst the explosion probability of friction is 20% lower than that of ultrafine HMX. Ultrafine HMX/TATB explosive co-crystals are difficult to initiate under impact and friction conditions.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 4; 876-887
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Proteomics profiles reveal the potential roles of proteins involved in chicken macrophages stimulated by Lipopolysaccharide
Autorzy:
Li, S.
Chen, Y.
Xue, W.
Wang, Q.
Huai, Z.
An, C.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/16647586.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
chicken macrophage (HD11)
immune response
lipopolysaccharide (LPS)
proteomics
Opis:
Lipopolysaccharide (LPS), a core part of gram-negative bacteria, is crucial for inducing an inflammatory response in living things. In the current study, we used LPS from Salmonella to stimulate chicken macrophages (HD11). Proteomics was used to investigate immune-related proteins and their roles further. Proteomics investigation revealed 31 differential expression proteins (DEPs) after 4 hours of LPS infection. 24 DEPs expressions were up-regulated, while seven were down-regulated. In this investigation, ten DEPs were mainly enriched in S. aureus infection, complement, and coagulation cascades, which were all implicated in the inflammatory response and clearance of foreign pathogens. Notably, complement C3 was shown to be up-regulated in all immune-related pathways, indicating that it is a potential protein in this study. This work contributes to a better understanding and clarification of the processes of Salmonella infection in chickens. It might bring up new possibilities for treating and breeding Salmonella-infected chickens.
Źródło:
Polish Journal of Veterinary Sciences; 2023, 26, 2; 265-274
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation Method for the Bandgap of Antimonide Based Multicomponent Alloys
Autorzy:
An, N.
Liu, C.
Fan, C.
Dong, X.
Song, Q.
Powiązania:
https://bibliotekanauki.pl/articles/1030612.pdf
Data publikacji:
2018-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Ea
42.55.Px
81.15.Hi
Opis:
As the most important material parameter of semiconductor, bandgap is necessary to be investigated to meet the design requirements of the high-performance optoelectronic devices. A new method of is proposed to calibrate the bandgap of antimonide based multi-component alloys with considering the effect of spin-orbit splitting off bands and the doublet degeneracy of valance band on the bandgaps of Sb-containing materials. A correction factor is introduced in the conventional calculation, and the spin-orbit splitting method is proposed. Besides, the In_xGa_{1-x}As_ySb_{1-y} films with different compositions are grown on GaSb substrates by molecular beam epitaxy, and the corresponding bandgaps are obtained by photoluminescence to test the accuracy and reliability of this new method. An error rate analysis reveals that the α calculated by the spin-orbit splitting correction method is decreased to 2%, almost one order of magnitude smaller than the Moon method, which means that the new method can calculate the antimonide multicomponent more accurately with some applicability. This work can give a reasonable interpretation for the reported results and beneficial to tailor the antimonides properties and optoelectronic devices.
Źródło:
Acta Physica Polonica A; 2018, 133, 1; 118-120
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulated impacts of rainfall extremes on yield responses of various barley varieties in a temperate region
Autorzy:
Yoon, C.Y.
Kim, S.
An, K.N.
Powiązania:
https://bibliotekanauki.pl/articles/2083065.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
barley
rainfall
simulation
food cost
grain
yield
Opis:
As population rises, more people need to be fed. With increasing income, the potential exists for increases in the demand for cereals (i.e., barley). Since barley has a high level of tolerance to environmental stressors, this crop has been recommended as a potential crop for food security in marginal environments. In this study, a crop growth Agricultural Land Management Alternatives with Numerical Assessment Criteria model, was parameterized and used to simulate the yields of two barley types grown in a temperate environment at a latitude of 35°N. In order to apply this crop model to barley, 19 years of field data were used to model calibration and validation. As a result, the ALMANAC model accurately simulated yields for both barley types. The validated model was used to predict yields under three diverse seasonal rainfall scenarios associated with different patterns of the Central Pacific El Niño influence. According to the simulation results, excessively high seasonal rainfall decreased barley yields. Crop price and annual revenue of the two barley types were also evaluated using a non-linear regression model. For the malt type, the food price was higher with a higher rainfall, while naked barley had a higher revenue under the conditions of a lower rainfall.
Źródło:
International Agrophysics; 2021, 35, 2; 119-129
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the effect of planting distance and harvesting time on the carotenoids and phytochemicals of selected orange-fleshed sweet potato varieties
Autorzy:
Kalu, O.O.
Ojimelukwe, P.C.
Ukom, A.N.
Powiązania:
https://bibliotekanauki.pl/articles/11369.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Źródło:
International Letters of Natural Sciences; 2017, 66
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between sunshine duration and global solar radiation in South-Eastern Romania
Autorzy:
Paltineanu, C.
Mihailescu, I.F.
Torica, V.
Albu, A.N.
Powiązania:
https://bibliotekanauki.pl/articles/24665.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
global solar radiation
Romania
air temperature
air humidity
sunshine duration
extra-terrestrial radiation
Źródło:
International Agrophysics; 2002, 16, 2
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
STM Study on the (100) Surface of the Ag-In-Yb 1/1 Cubic Approximant
Autorzy:
Cui, C.
Sharma, H.
Nugent, P.
Shimoda, M.
Pang Tsai, An
Powiązania:
https://bibliotekanauki.pl/articles/1373497.pdf
Data publikacji:
2014-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.44.Br
68.35.B-
68.37.Ef
Opis:
Scanning tunneling microscopy studies have revealed a periodic step-terrace structure in the (100) surface of the Ag-In-Yb 1/1 cubic approximant. The step height between the large terraces is about 0.73 nm, approximately one-half of the lattice constant, which is consistent with the bcc-like crystalline structure of this crystal. Two small terraces are observed between the adjacent large terraces. High-resolution STM images of the large terrace exhibit a square lattice of protrusions with a lattice constant of about 1.55 nm, which is consistent with the bulk lattice constant. The scanning tunneling microscopy results suggest that the large terraces are associated with the planes that intersect the centers of rhombic triacontrahedral clusters (the building unit of the crystal) and show the highest atomic density along the [100] axis. It is highly likely that the small terraces are related to moderate atomic density planes and are less stable than the large terraces.
Źródło:
Acta Physica Polonica A; 2014, 126, 2; 577-580
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of antidote potential of methanol leaf extract of Bauhinia monandra on heparin-induced thrombocytopenia in mice
Autorzy:
Nworie, K.M.
Okorie, A.N.
Ebere, D.N.
Obike, O.C.
Powiązania:
https://bibliotekanauki.pl/articles/79858.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thrombocytopenia
methanol extract
leaf extract
Bauhinia monandra
antidote potential
phytochemical
mice
mouse
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2019, 100, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occurrence of a new sulphate mineral: Ca7Na3K(SO4)9 in the Emet borate deposits, western Anatolia (Turkey)
Autorzy:
García-Veigas, J.
Ortí, F.
Rosell, L.
Gündog(an, I.
Helvac, C.
Powiązania:
https://bibliotekanauki.pl/articles/2059025.pdf
Data publikacji:
2010
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Miocene
K-sulphate
emetite
glauberite
probertite
evaporites
Opis:
Emetite, a new sulphate mineral, Ca734
Źródło:
Geological Quarterly; 2010, 54, 4; 431-438
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of Al Nanoparticles and Their Influence on the Thermal Decomposition of RDX
Autorzy:
Hou, C.
Geng, X.
An, Ch.
Wang, J.
Xu, W.
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/358260.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
Al nanoparticles
properties
RDX
thermal decomposition
Opis:
Aluminum (Al) nanoparticles were prepared by the DC arc plasma method in order to study the influence of Al nanoparticles on the thermal decomposition of cyclotrimethylenetrinitramine (RDX). The Al powder was characterized by TEM, BET, XRD, and LSA, and the thermal decomposition of RDX and RDX/nanometer Al were examined by DSC. Based on the DSC curves, the thermal decomposition parameters of the samples were calculated and compared. The results showed that the particles of Al are homogeneous and fine, and that the surface is smooth. The TEM results showed that the nanoparticles are spherical, with an average diameter of approximately 60 nm. The peak temperature of RDX decomposition decreased by 4.36 K at the heating rates of 5, 10, and 20 K/min after the addition of nano-Al powder, and the activation energy for decomposition decreased by about 11 kJ/mol. Furthermore, the critical explosion temperature was also reduced. These observable changes indicate that Al nanoparticles act as catalysts for the thermal decomposition of RDX.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 1; 123-133
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water quality challenges and impact
Autorzy:
Obilonu, A.N.
Chijioke, C.
Igwegbe, W.E.
Ibearugbulem, O.I.
Abubakar, Y.F.
Powiązania:
https://bibliotekanauki.pl/articles/11787.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
water quality
water body
environment pollution
prevention
treatment
challenge
impact
waste water
acid rain
fish
sediment
pollutant
Opis:
Man’s activities on the environment often results in pollution and degradation of water bodies. Water bodies must therefore be jealously guided and protected from being polluted, which will affect water quality and availability for desired usage. Causes of water quality impairment are urban and rural storm water runoff, inadequate waste water treatment, nutrient entrophication, atmospheric deposition and acid rain, pollutant in sediments and fish, and nuisance aquatic weed growth and invasive species. Other factors include unhygienic disposal and inadequate treatment of human and livestock wastes, indecent management and treatment of industrial residues, inappropriate agricultural practices and unsafe solid waste discharge. Suggested strategies to combat water quality problems which should form the basis of policy solution for improving water quality include: (i) prevention of pollution; (ii) treatment of polluted water; (iii) safe use of waste water; and (iv) restoration and protection of ecosystem. It is recommended that our water bodies and the environment in general should be protected through appropriate legislation guidelines and public literacy campaign and mass education to sensitize, educate and make the people a fully environmentally literate society. Taking these steps internationally, nationally and locally will mean better water quality for our present society and future generation.
Źródło:
International Letters of Natural Sciences; 2013, 04
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Safety of honey consumed in Enugu State, Nigeria: a public health risk assessment of lead and polycyclic aromatic hydrocarbons
Autorzy:
Ozoani, H.A.
Ezejiofor, A.N.
Amadi, C.N.
Chijioke-Nwauche, I.
Orisakwe, O.E.
Powiązania:
https://bibliotekanauki.pl/articles/874918.pdf
Data publikacji:
2020
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Opis:
Background: Information about lead (Pb) and polycyclic aromatic hydrocarbons (PAHs) concentrations in honey and their dietary intake is very important in human health risk assessment. Currently, there are paucity of data on the risk assessment and concentrations of lead and PAHs in honey in Nigeria. Objective: This study has determined the potential human health risk of lead and PAHs associated with the consumption of honey in Enugu state, Nigeria. Materials and methods: Lead and US EPA 16 priority PAHs in honey harvested from rural and urban communities in March 2016 were determined using Atomic Absorption Spectrometer and Gas Chromatograph respectively. Carcinogenic and non-carcinogenic risk assessments were carried. Results: The mean concentration of Pb in honey ranged from 0.005 mg/kg – 0.08 mg/kg. The mean concentrations of 16 PAHs in honey ranged from 4.71E-03 – 2.72 mg/kg. The dietary intake of the PAHs for adults and children ranged from 0.0021 – 0.0259 mg/kg/day and 0.0011 – 0.0129 mg/kg/day respectively. The levels of BaPeq and their margin of exposure MOE suggest non-significant health risk. The incremental life cancer risk ILCR of Pb were within safe range of <1E-04. Conclusion: Consumption of honey from Enugu State, Nigeria may not pose a significant health risk.
Źródło:
Roczniki Państwowego Zakładu Higieny; 2020, 71, 1
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Eocene South American native ungulates from the Quebrada de los Colorados Formation at Los Cardones National Park, Argentina
Autorzy:
Fernandez, M.
Zimicz, A.N.
Bond, M.
Chornogubsky, L.
Arnal, M.
Cardenas, M.
Fernicola, J.C.
Powiązania:
https://bibliotekanauki.pl/articles/2082287.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Mammalia
South American native ungulates
Casamayoran SALMA
Paleogene
Quebrada de Los
Colorados Formation
Argentina
Opis:
In the last few years, the Quebrada de Los Colorados Formation has become an important middle Eocene fossiliferous unit in Northwestern Argentina. In this unit, the South American native ungulates were until now only represented by the order Notoungulata, including one family of Typotheria and three of Toxodontia. In this contribution, we present a new faunistic assemblage of South American native ungulates, collected from outcrops of the Quebrada de Los Colorados Formation at Los Cardones National Park, Calchaquí Valleys, Salta Province (Argentina). This new assemblage is constituted by the following taxa: litoptern Didolodontidae cf. Ernestokokenia sp., Astrapotheria indet., and notoungulate Notostylopidae Homalostylops sp., a ?Homalostylops sp., typothere “Oldfieldthomasiidae” Colbertia falui sp. nov., Colbertia lumbrerense, and Colbertia sp. and toxodont “Notohippidae” Pampahippus secundus. Colbertia falui sp. nov. differs from the other species of Colbertia by the following features: lower cheek teeth with both more labially angular and oblique trigonid; lower premolars more labio-lingually compressed; with proportionally larger trigonid, and shorter talonid; ectoflexid transversally deeper; lower molars with a more developed paralophid, and more expanded metalophid and entoconid; the latter is located in a more mesial position, being closer to the metaconid; deep and lingually narrower talonid basin; disto-lingual sulcus transversally shallower; more developed cingulids; and m3 with less lingually projected hypoconulid. This new fauna markedly increases the taxonomic richness known for this formation since it includes the first mention of notostylopids, “oldfieldthomasiids”, litoptern didolodontids, and astrapotheres. With the current evidence, we postulate an ungulate migration from Patagonia to Northwestern Argentina during the Eocene. We also hypothesize that the observed taxonomic differences among the Quebrada de Los Colorados, Geste, and Lumbrera formations are more probably associated to orogenic factors that have regulated the faunal dynamic in Northwestern Argentina during the Paleogene than to a differential sampling effort or taphonomic biases.
Źródło:
Acta Palaeontologica Polonica; 2021, 66, 1; 85-97
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology Change Of Si Deposit In Molten Salt Electrorefining
Zmiana morfologii osadu Si podczas elektrorafinacji w stopionych solach
Autorzy:
Ryu, H. Y.
Kwon, S. C.
Han, M. H.
An, Y. S.
Lee, J. S.
Lee, J. H.
Powiązania:
https://bibliotekanauki.pl/articles/354346.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
molten salt
silicon
morphology
electrorefining
current density
sól stopiona
krzem
morfologia
elektrorafinacja
gęstość prądu
Opis:
The effects of processing parameters on the morphology change in a Si deposit recovered by means of molten salt electrorefining are evaluated using electrochemical techniques such as cyclic voltammetry and chronopotentiometry at 800°C. It was found that concentration of K2SiF6 and current density were important parameters in determining deposit size. Higher concentrations of K2SiF6 were effective in coarsening the silicon deposit and decreasing the cell potential. Silicon nanofiber was recovered at 5 wt% of K2SiF6 whereas dense particles were prepared at 30 and 50 wt% of K2SiF6. The morphology of the Si deposit was determined by the concentration of Si in the electrolyte which is related to the formation of crystal and growth of Si. The formation mechanism of the Si deposit was interpreted by using high resolution TEM as well as electrochemical properties.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1491-1497
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Epidemiology of tree-hole breeding mosquitoes in the tropical rainforest of Imo State, South-East Nigeria
Autorzy:
Anosike, J C
Nwoke, B.E.B.
Okere, A.N.
Oku, E.E.
Asor, J.E.
Emmy-Egbe, I.O.
Adimike, D.A.
Powiązania:
https://bibliotekanauki.pl/articles/50771.pdf
Data publikacji:
2007
Wydawca:
Instytut Medycyny Wsi
Tematy:
ecology
South-East Nigeria
yellow fever
mosquito
epidemiology
tree hole
Nigeria
human disease
Imo State
forest reserve
disease vector
rural area
tropical region
Opis:
The study of tree-hole breeding mosquitoes was carried out in the tropical rainforest of Imo State Nigeria (two rural areas and two forest reserves in some parts of Orlu Senatorial Zone) between May – October 2002. Using standard entomological procedures, two macrohabitats (natural tree-holes and bamboo traps) and two microhabitats (leaf axils of cocoyams/pineapples and leaf axils of plantain/banana) were sampled for various mosquito species. Mosquitoes were recovered from all the various biotypes sampled. Types of mosquitoes species encountered, their relative abundance, as well as genera varied signifi cantly during the study (p<0.05). Four genera of mosquitoes: Aedes, Culex, Anopheles and Toxorhynchites were recovered while 16 species of mosquitoes encountered include: Aedes aegypti, Ae. africanus, Ae. simpsoni, Ae. albopictus, Ae. stokesi, Ae. taylori, Ae. apicoargenteus, Culex quinquefasciatus, Cx. nebulosus, Cx. trigripes, Cx. decens, Anopheles gambiae, An. funiestus, An. coustani and Toxorhynchites viridibasis. Most of the mosquitoes showed oviposition preferences for one or more habitats. The presence of Ae. africanus, Ae. simpsoni and Ae. aegypti indicate that the study areas were at risk of yellow fever epidemic. The presence of Anopheles and Culex species ensured endemicity of malaria and fi lariasis, while the recovery of Ae. albopictus in this region suggests a possible outbreak of dengue fever in future if not properly controlled.
Źródło:
Annals of Agricultural and Environmental Medicine; 2007, 14, 1
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Bending, Impact Fracture Behavior and Characteristics of Stainless Steel Clad Plates with Different Rolling Temperature
Autorzy:
An, Q.
Fan, K. Y.
Ge, Y. F.
Liu, B. X.
He, J.
Wang, S.
Chen, C. X.
Ji, P. G.
Tolochko, O.
Powiązania:
https://bibliotekanauki.pl/articles/2049433.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
stainless steel clad plate
interface characteristics
bending behavior
impact morphologies
delamination crack
Opis:
The interface characteristics, bending and impact behavior, as well as fracture characteristics of stainless steel clad plates fabricated by vacuum hot rolling at different rolling temperatures of 1100°C, 1200°C and 1300°C are investigated in detail. The interface bonding strength is gradually increased with the increasing rolling temperature due to the sufficient diffusion behavior of alloy element. The bending toughness and impact toughness are gradually decreased, while the bending strength increase with the increase of the rolling temperature, which is attributed to mechanisms of matrix softening and interface strengthening at high rolling temperature. Due to the weak interface at 1100°C, the bending and impact crack propagation path was displaced by delamination cracks, which in turn lead to reduction in stress intensity of the main crack, playing an effective role in toughening the stainless steel clad plates. Moreover, the impact fracture morphologies of clad plates show a typical ductile-brittle transition phenomenon, which is attributed to the matrix softening behavior with the increasing rolling temperature.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 1; 229-239
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
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