Dependence of impact regime boundaries on the initial temperatures of projectiles and targets

Towards higher impact velocities,ballistic events are increasingly determined by the material temperatures.Related effects might range from moderate thermal softening to full phase transition.In particular,it is of great interest to quantify the conditions for incipient or full melting of metals during impact interactions,which result in a transition from still strength-affected to hydrodynamic material behavior.In this work,we investigate to which extent the respective melting thresholds are also dependent on the initial,and generally elevated,temperatures of projectiles and targets before impact.This is studied through the application of a model developed recently by the authors to characterize the transition regime between high-velocity and hypervelocity impact,for which the melting thresholds of materials were used as the defining quantities.The obtained results are expected to be of general interest for ballistic application cases where projectiles or targets are preheated.Such conditions might result,for example,from aerodynamic forces acting onto a projectile during atmospheric flight,explosive shapedcharge-jet formation or armor exposure to environmental conditions.The performed analyses also broaden the scientific understanding of the relevance of temperature in penetration events,generally known since the 1960s,but often not considered thoroughly in impact studies.

Uncommon and Impact-Suspicious Geologic Phenomena across Jordan and Adjacent Areas, Arabian Plate

For the discovery and analysis of Jebel Waqf as Suwwan (JWS) Impact Crater, Jordan pushed the authors to consequently focusing on other unusual geologic phenomena such as circular/oval structures (some of “crypto-volcanic” origin), disharmonic folding, horizontal stylolites, and a broad stripe of?Sanidine-Hornfels-Facies, all of them hosted in Upper Cretaceous/Paleogene carbonate rocks exposed across Jordan and adjacent areas. Shatter cones are the most useful tools during field work in the realm of circular structures. In addition to the impact-geologic data of JWS Impact Structure hitherto available, the cooling process of melted Lower Cretaceous Kurnub-Sandstone could be verified by microscopically identified SiO2-modifications between the melting point (1714°C) and low temperatures. In comparison with the Suffield 500 tons explosion tests [20] and with the Ries Impact Crater, Germany, excavation and vaporization processes of target rocks demand drilling between Central Uplift and Inner Ring of the JWS Impact Structure (“Chert-Carbonate-Impact-Chess Game”). In a scenario: “Impacting meets Plate Tectonics”, phenomena like disharmonic folding, horizontal stylolites, and an abundance of circular/oval structures of high diameter variation through northwest Jordan are discussed under aspects of gravitational gliding, effects of seismic surface waves (Love-), transpressional structures related to Jordan Rift-Tectonics, and possible impact processes of unknown number occurred on the Arabian Plate in southeastern direction with northwest-directed impulse. The so-called “Mottled Zone” of Jordan and Palestine owning a high number (~100) of mineral neoformations with formation temperatures up to ~1120°C(pseudo-wollastonite = β-CaSiO3), is to be interpreted as of “Sanidine-Hornfels-Impact Facies” under ricochet conditions along an “Avenue of Ricochet-Impact-Thermo-Cataclysm”. Marble-related travertines represent a low temperature facies of the impact event. The temporal projection of patterns like Rapid Climate Change (RCC), astrophysical data [Hoyle’s Comet: 47], acid events in ice-cores, tektite fall, Rise and Fall of Neolithic/Bronze Age Cultures, reveals an amazing “Ensemble” of coincidences among all of these parameters since the Middle/Upper Pleistocene boundary throughout Holocene. Ten short Interval Cases are discussed as being “Rare Event”- suspicious. Myths like the “Gilgamesch Epos” and “John’s Apocalypse” surprisingly provide realistic hints on impact events comparable with modern observations and experiments, which are: approach of extraterrestrial bodies, impact cratering, earthquakes and faulting, supercyclonic whirl-storms (wildfires), effects of hot ejecta, destruction of fauna, flora, and cities, long-lasting flooding, darkness caused by ashes and dust circulating in atmosphere and stratosphere (sintwinter), and environmental pollution. Such hints were handed down in myths of ~180 ethnic peoples around the globe. “High probability Cases” focus on impact events on ~9600 yr B.P and on ~6000 yr B.P. Other “Rare Events” may have possibly occurred about ~8000 yr B.P. and on ~3200 yr. B.P. (all radiocarbon yr.cal.). Core-drilling in the pull-apart basins of the Jordan Rift System (Dead Sea, Lake Tiberias) as traps having possibly preserved volcanic and impact ejecta would be a challenging international and interdisciplinary project.

Impact of black cherry on pedunculate oak vitality in mixed forests:Balancing benefits and concerns

The vitality of European forests continues to decline due to new pests and diseases,climate-change related disturbances and high loads of atmospheric nitrogen deposition.Deteriorating soil health is a major factor underpinning the low vitality of West-European forests.Selecting tree species with soil ameliorative traits is proposed as an avenue to counteract soil acidification and improve overall forest vitality.Here we evaluate the impact of black cherry(Prunus serotina Ehrh.),a known rich litter species,on the vitality of neighboring pedunculate oak(Quercus robur L.)in ten mixed forests on sand in Germany,Belgium and the Netherlands.We found that black cherry admixture increases foliar N and P to a surplus whereas it causes deficiencies in foliar Mg,thereby resulting in an overall negative effect on oak foliar nutrient concentrations.Contrary,defoliation of oak leaves by herbivory decreases with the proximity of black cherry.Using structural equation modelling(SEM),we tested the hypothesized‘improved soil health’pathway.Our analyses showed that black cherry admixture leads to lower accumulation in the humus layer,resulting in higher soil base saturation which has a positive effect on foliar Ca yet a negative effect on total chlorophyll.Moreover,the SEM illustrated that herbivory of oak leaves decreases when black cherry is admixed,both via dilution and improved soil health.Indirect effects of black cherry on oak vitality via“improved soil health”in our SEM are however small in comparison to direct relations.Hence,our study showed that the combined positive and negative impacts of black cherry on oak vitality are limited,which tempers the potential benefits of using the rich litter species to counteract oak decline via improved soil health–yet,the concern of black cherry as an invasive alien species negatively affecting the vitality of mature pedunculate oak trees may also be exaggerated.

The Last 15,000 Years: Climate-Controlled and “Rare-Event”-Triggered/Rise and Fall of Holocene Cultures in the Near/Middle East and in Central Europe—Evidence and Background

Pushed by the results of a preceding publication on the possibly Quaternary Jebel Waqf as Suwwan Meteorite Crater, Jordan [5], where an amazing coincidence of Rapid Climate Changes (RCCs) with Rise and Fall of Neolithic and Bronze Age Cultures became evident for the Near/Middle East, this paper deals with the same subject, however, relating to the complete Holocene period in the same area and, additionally, in Central Europe as well. By application of modern climatic data [6] comprising isotope analysis (δ18O, 14C, 10Be), acid and aerosol events, and greenhouse gases (CO2, CH4) Greenland ice cores as well as other astro-/geophysical and geological parameters, an overwhelming coincidence/relation/interdependence of both natural and cultural evidences becomes obvious throughout the last 15,000 years across the Northern Hemisphere. Apart from solar output and other astrophysical processes, most important climate- and Earth-related parameters are Mega-Volcanism (i.e.Santorini Greece: ~3640 yr cal. B. P.), Impact Events (i.e. during Mesolithic: ~9600 yr cal. B. P), rapid oceanic current change (DO-Events), and Plate Tectonics (possibly Atlantis-Event: ~11,500 yr cal. B.P. = Pleistocene/Holocene boundary). The most essential parameter is a significant temperature change related to more or less restricted latitude realms of the Northern Hemisphere. Thus, glacier advance/retreat controls the mobility of peoples (i.e. Nations' Migration, Teutonic Empires) and the access to ore deposits (Au, Ag, Cu, Sn, Zn, Pb, Fe) located in Alpine Mountain Ranges (i.e. End-Neolithic, Early Bronze Age). Myths like the Gilgamesh Epos and John Apocalypse convincingly reveal realistic contents relating to natural hazards like tsunamis, impact and flooding events. They unmisunderstandably make obvious that Myths may provide valuable contributions, especially to Geosciences. Some of the controlling parameters interrelate with others or present a kind of hierarchy: Mega-Volcanism/impact events à ejecta à wildfires, heat storms à cosmic winter, sint winter à stop of photosynthesis à mass extinction environmental pollution à greenhouse effects. Significant events (21 cases in total) occurred on i.e.

Computer modeling of high-pressure leaching process of nickel laterite by design of experiments and neural networks

Due to the complex chemical composition of nickel ores, the requests for the decrease of production costs, and the increase of nickel extraction in the existing depletion of high-grade sulfide ores around the world, computer modeling of nickel ore leaching process be- came a need and a challenge. In this paper, the design of experiments （DOE） theory was used to determine the optimal experimental design plan matrix based on the D optimality criterion. In the high-pressure sulfuric acid leaching （HPSAL） process for nickel laterite in ＂Rudjinci＂ ore in Serbia, the temperature, the sulfuric acid to ore ratio, the stirring speed, and the leaching time as the predictor variables, and the degree of nickel extraction as the response have been considered. To model the process, the multiple linear regression （MLR） and response surface method （RSM）, together with the two-level and four-factor full factorial central composite design （CCD） plan, were used. The proposed re- gression models have not been proven adequate. Therefore, the artificial neural network （ANN） approach with the same experimental plan was used in order to reduce operational costs, give a better modeling accuracy, and provide a more successful process optimization. The model is based on the multi-layer neural networks with the back-propagation （BP） learning algorithm and the bipolar sigmoid activation function.

Did Major Impacts Affect Sedimentologic/Sequence-Analytical Pattern of the Early Palaeozoic Sedimentary Systems of Jordan,Arabian Plate?

Based on profound sequence-analytical data of the early Palaeozoic sedimentary systems of Jordan, Arabian Plate, a correlation attempt is proposed with regard to possible major impact events after Price [10]. His methodological concept tells that abrupt 441 Ma. Referring to the fact that major impacts may trigger, respectively influence, exogenic and endogenic processes on an over-regional, even global, extent, this paper put the “sensitive” geological setting of Jordan at the Arabian Platform’s margin into focus. That mainly concerns the early Palaeozoic coastlines as to sea level change as well as the Jordan Valley Rift as being possibly to susceptible for tectonic re-activation changes of both direction and speed of plate motions would indicate such convulsive processes as occurred on: 550 Ma, 526.5 Ma, 514 Ma, 502 Ma, 456/455.4 Ma, and following triggering of magmatism at the Precambrian/Cambrian boundary. The following phenomena are taken into account: Faulting and magmatism triggered along the Jordan Valley Rift (Wadi Araba) in connection with the Pan-African Orogeny, anoxic sediments, temporary high detrital input onto the adjoining stable platform from Gondwana hinterlands, and significant chemical weathering in the Gondwana source areas by intensive acid (nitric) rain directing mineral content variation in the “Nubian Sandstones” (e.g. feldspar, kaolinite/dickite, tourmaline).

A Novel Medium Access Control Protocol for Real-Time Wireless Communications in Industrial Automation

In this paper, a novel Medium Access Control (MAC) protocol for industrial Wireless Local Area Networks (WLANs) is proposed and studied. The main challenge in industry automation systems is the ultra-low network latency with a target upper bound in the order of 1 ms while maintaining high network reliability and availability. The novelty of the proposed wireless MAC protocol resides in its similar latency performance as its counterpart in wired industrial LAN. First, the functional design of the MAC protocol is introduced. Then its performance results gained from hardware implementation (SystemC and VHDL) on an FPGA platform are presented. Finally, a real-time communication module which achieves the ultra-low latency required in industrial automation is described.

Prevalence and antimicrobial susceptibility patterns of bacteria in ICU patients with lower respiratory tract infection: A cross-sectional study

Objective: To investigate the prevalence of isolated organisms in patients with lower respiratory tract infections and the antibiotic susceptibilities at a tertiary care center. Methods: In this observational and cross-sectional analysis, 114 patients admitted in the intensive care unit were enrolled. The endotracheal aspirates and bronchoalveolar lavage were collected. The bacteria were isolated and identified, and finally, antimicrobial sensitive pattern of the isolated bacteria was examined. Results: The prevalence of infection was 72.72% in male patients and 27.28% in females. The predominant bacteria were Klebsiella pneumoniae (37.50%) followed by Acinetobacter spp. (36.36%), Pseudomonas aeruginosa (7.95%),Escherichia coli (6.81%), Proteus mirabilis (2.27%), atypical Escherichia coli (1.13%), Enterococcus spp. (1.13%),Elizabethkingia meningoseptica (1.13%),Staphylococcus aureus (1.13%),Proteus vulgaris (1.13%), Citrobacter freundii (1.13%), and Citrobacter koseri (1.13%). High resistance to cephalosporins (82.18%) was demonstrated in all Gram-negative bacteria. Bacteria showed susceptibility to colistin (88.75%) followed by tigecycline (83.11%), gentamycin (36.18%), and amikacin (49.23%). Conclusions: As the most frequent respiratory organisms, Klebsiella pneumoniae and Acinetobacter spp. have increased resistance to cephalosporins and susceptibility to colistin followed by tigecycline.

Animal models of acute gastric mucosal injury: Macroscopic and microscopic evaluation

Acute gastric mucosal injury is a common disorder of the gastrointestinal tract and the search for new therapeutics is ongoing. The aim of this study is to update and expand the information related to the most widely used rat models of acute gastric ulcer, the ethanol‐induced ulcer and the indomethacin‐induced ulcer. These two models are compared in terms of macroscopic and microscopic features. Experimentally, ethanol was given orally in a single dose and indomethacin was subcutaneously injected into male Wistar rats. After ulcerative challenges, the stomachs were removed and visually inspected. Anti‐ulcerative drugs were used to validate the models. Histological analysis of the stomachs determined the microscopic score. The methodology used for model evaluation applied to macroscopic and microscopic gastric lesions. With these methods it was possible to induce lesions in the gastric mucosa. Microscopic evaluation permitted assessment of the inflammatory and apoptotic impact in the mucosa not observable by macroscopic evaluation. Groups of animals were treated with two standard drugs: sulcralfate suspension or lansoprazole solution. Both drugs reduced macroscopic and microscopic lesions, particularly the hemorrhagic ones. Both models induced acute gastric mucosal injury and no single evaluation method can address all the aspects of the pathology of gastric lesions. As a complement to macroscopic evaluation, microscopy appears to be a relevant tool to selectively identify specific aspects of the development of mucosal injury, quantify the extent of lesions, and contribute to an appropriate interpretation of results. The score systems established here offer a reliable method for testing antiulcer drugs.

The Born-Oppenheimer Approximation Revisited

We present an improved Born-Oppenheimer method for the treatment of molecules. Our development is based on taking into account a portion of the kinetic energy which was inadvertently omitted by Born and Oppenheimer. Our theory replaces the set of standard atom-atom potentials by an evolution operator. In particular, in contrast to the traditional Born-Oppenheimer method our amended basis describes the so-called Wannier phenomenon which deforms potential surfaces, and traps one or more threshold electrons into an unstable equilibrium. Within our framework that trapping manifests itself as a Fresnel distribution. Finally we discover a π/2 phase jump in the evolution operator caused by the diffraction of a two-electron wave from a potential ridge.

Physical activity in primary and secondary prevention of cardiovascular disease:Overview updated

Although the observed progress in the cardiovascular disease treatment, the incidence of new and recurrent coronary artery disease remains elevated and constitutes the leading cause of death in the developed countries. Three-quarters of deaths due to cardiovascular diseases could be prevented with adequate changes in lifestyle, including increased daily physical activity. New evidence confirms that there is an inverse dose-response relationship between physical activity and cardiovascular disease and mortality risk. However, participation in moderate to vigorous physical activity may not fully attenuate the independent effect of sedentary activities on increased risk for cardiovascular diseases. Physical activity also plays an important role in secondary prevention of cardiovascular diseases by reducing the impact of the disease, slowing its progress and preventing recurrence. Nonetheless, most of eligible cardiovascular patients still do not benefit from secondary prevention/cardiac rehabilitation programs. The present review draws attention to the importance of physical activity in the primary and secondary prevention of cardiovascular diseases. It also addresses the mechanisms by which physical activity and regular exercise can improve cardiovascular health and reduce the burden of the disease.

Monitoring of central corneal thickness after phacoemulsification—comparison of statical and rotating Scheimpflug pachymetry,and spectral-domain OCT

AIM:To explore the possibility of deploying three contactless devices(static and rotating Scheimpflug technology,spectral domain optical coherence tomography)for measuring central corneal thickness(CCT)in preoperative and postoperative examinations of cataract patients.METHODS:Totally 72 patients who had undergone surgery without complications were selected.The CCT was measured prior to the operation,as well as on the first,5th-7th and 28th day following the operation using the Nidek NT 530-P,Sirius?,and Topcon OCT-2000 devices.RESULTS:A significant postoperative increase and subsequent decrease in CCT was identified with all three devices.The correlations were highly significant and thus reflect a very good degree of comparability at all times with the exception of the rotating Scheimpflug camera.The postoperative results from the latter differed significantly from the other devices.The correlations were Sirius/Topcon(P=0.010)and Sirius/Nidek(P<0.0005).No statistically significant difference could be identified in the comparison between Topcon and Nidek(P=0.056).CONCLUSION:All three devices are suitable for postoperative monitoring of CCT.The measurement results are only comparable to a limited extent and not interchangeable in the course of treating a single patient.This is due to the different imaging technology used in the devices and the resulting modalities for conducting the measurements.

IMS国内商用迈入新阶段 业务创新仍待强化

相比国内运营商,国外运营商胆子更大一些,能更多地与互联网应用企业进行深度合作和终端定制开发。近期,中国电信IMS一期集采结束,华为、中兴、上海贝尔三家厂商瓜分了十个省份的大单。

A New Species of Trimeresurus Lacépède, 1804(Squamata: Viperidae) from Southwestern China, Vietnam, Thailand and Myanmar

The pit vipers of the genus Trimeresurus Lacépède, 1804 is one of the largest groups of Asian snakes, distributed from India to China and Indonesia. Recent surveys in Jiangcheng and Simao, Yunnan Province, China resulted in a new species previously allocated to T. albolabris. Combining morphological and molecular data, we describe it as Trimeresurus guoi sp. nov. The new species morphologically differs from T. albolabris in the yellow green ventral color;an indistinct ventrolateral line;the a bsence of a postocular stripe;the firebrickred iris;a dark red stripe on dorsal tail;hemipenes with relatively weak sparse papillae, reaching 23 rd subcaudal when unextruded. Molecularly, the new species forms a clearly divergent lineage(BPP 1.00/UFB 100). Uncorrected pairwise distances of mitochondrial gene Cyt b between the new species and other known species of the subgenus Trimeresurus range from 0.052(T. albolabris) to 0.071(T. insularis).

阿尔卡特朗讯IMS:引领通信新时代

IMS标准的积极推动者；IMS融合解决方案的框架；技术创新的IMS融合解决方案；

Quantifying the parameter dependent basin of the unsafe regime of asymmetric Lévy-noise-induced critical transitions

In real systems,the unpredictable jump changes of the random environment can induce the critical transitions(CTs)between two non-adjacent states,which are more catastrophic.Taking an asymmetric Lévy-noise-induced tri-stable model with desirable,sub-desirable,and undesirable states as a prototype class of real systems,a prediction of the noise-induced CTs from the desirable state directly to the undesirable one is carried out.We first calculate the region that the current state of the given model is absorbed into the undesirable state based on the escape probability,which is named as the absorbed region.Then,a new concept of the parameter dependent basin of the unsafe regime(PDBUR)under the asymmetric Lévy noise is introduced.It is an efficient tool for approximately quantifying the ranges of the parameters,where the noise-induced CTs from the desirable state directly to the undesirable one may occur.More importantly,it may provide theoretical guidance for us to adopt some measures to avert a noise-induced catastrophic CT.

LARGE TIME ASYMPTOTIC BEHAVIOR OF THE COMPRESSIBLE NAVIER-STOKES EQUATIONS IN PARTIAL SPACE-PERIODIC DOMAINS

In this article, we study the large time behavior of the 3-D isentropic compressible Navier-Stokes equation in the partial space-periodic domains, and simultaneously show that the related profile systems can be described by like Navier-Stokes equations with suitable ＂pressure＂ functions in lower dimensions. Our proofs are based on the energy methods together with some delicate analysis on the corresponding linearized problems.

Role of magnifying narrow-band imaging endoscopy for diagnosis of Helicobacter pylori infection and gastric precancerous conditions:Few issues

Standard endoscopy with biopsy and narrow-band imaging with guided biopsy are techniques for the detection of Helicobacter pylori(H.pylori)-related gastritis and precancerous lesions.In this study,the authors compared standard endoscopy and magnified narrow-band imaging(commonly known as NBI-M)in the diagnosis of H.pylori infections,atrophic gastritis,and intestinal metaplasia.Although the sensitivity of NBI-M is better than standard endoscopy,the diagnostic accuracy did not differ substantially between the diagnostic modalities.Future prospective studies may guide endoscopists in difficult cases regarding which modality is more useful and cost-effective for the diagnosis of H.pylorirelated gastritis and precancerous conditions.