Hot Pulse Research Articles

Modern therapy for vasomotor symptoms of climacteric syndrome

As a result of the age-related decline in reproductive function, during the perimenopausal and postmenopausal periods female patients experience an estrogen deficiency state. Due to this state, symptoms of estrogen deficiency, which are combined into the concept of “climacteric syndrome”, begin to manifest. Climacteric syndrome is a complex of vegetative-vascular, mental, and metabolic-endocrine disorders that develop in women not only due to decrease in estrogen synthesis, but also the general ageing of the body. Clinical manifestations of the climacteric syndrome have a certain priority of development. With a decrease of the hormonal function of the ovaries, vasomotor disorders step forward. They represent all forms of autonomic regulation disorders, such as hot flashes, arterial pressure and pulse liability, respiratory disorders, hyperhydrosis, chills, and many others. In this article, the greatest emphasis is placed on the issue of vasomotor disorders, in particular hot flashes, in women of the perimenopausal and postmenopausal periods. Attention is paid to the medical and social component of the issue discussed. Given the fact that today the life expectancy of people, including women, is significantly increasing in the developed countries, a large number of females are faced with the issue of menopausal syndrome. The clinical manifestations of menopause not only have an extremely negative impact on the women’s quality of life, but also lay the groundwork for the development of more severe somatic disorders. The article also considers in detail the frequency of hot flashes, and the pathogenetic mechanisms of their development. The “gold standard” for the treatment of patients suffering from vasomotor disorders is particularly detailed. Today, the menopausal hormone therapy is recognized as the most effective therapeutic approach, which, subject to a personalized approach to patients and the absence of contraindications to its prescription, demonstrates high protective capabilities.

Kinematics motion of paddy in hot air pulse flow

This research aims to study the characteristic of paddy motion under the hot air pulse flow in the drying tube length 2 m by using the kinematics motion analysis. The equations of paddy motion are analyzed to evaluate the pattern of paddy motion, total distance that the paddy can travel through the drying tube and Reynolds number of paddy. Results found that Model I, II and III consume the paddy travel time of approximately 1.3, 5.0 and 2.2 s and give a total distance of 2.6, 2.7 and 2.5 m and they have maximum travel velocity of 4.12, 1.37 and 1.85 m/s respectively. When considering the Reynolds number, the models I, II and III give the most values from similar calculations with 1,837, 1,816 and 1,821 respectively. Based on various parameters from all of models, Model III was the closest characteristic of paddy motion to the actual movement in the system.

Microstructure evolution and mechanical properties of γ-TiAl honeycomb structure fabricated by isothermal forging and pulse current assisted diffusion bonding

The hot deformation behavior and pulse current assisted diffusion bonding (PCDB) behavior of sintered γ-TiAl based alloy with near gamma microstructure were investigated for fabricating honeycomb structure via isothermal forging - PCDB route. Honeycomb core structures were fabricated via isothermal forging at 1150–1250 °C with a nominal strain rate of 10−3 s−1 based on the hot deformation behavior of the sintered alloy. Additionally, the mechanical property and structural morphology demonstrated that the best forging parameter was forging at 1200 °C with a nominal strain rate of 10−3 s−1. Subsequently, the effects of bonding temperature, holding time, and bonding pressure on the microstructure evolution, plastic strain, and shear strength of the PCDB joints were investigated. The plastic strain and shear strength of the PCDB joints increased with increasing bonding temperature, time and stress, additionally, the fracture mode transformed from interfacial sliding fracture into substrate fracture with the optimization of bonding parameters. Furthermore, a sound metallurgical bonding joint with smaller plastic strain and shear strength as high as 92% of the base material was achieved at 1100 °C with a holding time of 20 min and a pressure of 25 MPa, showing priority compared to traditional hot pressing diffusion bonding process.

Hot Deformation Behavior and Pulse Current Auxiliary Isothermal Forging of Hot Pressing Sintering TiAl Based Alloys.

This paper focuses on the fabrication of as-forged Ti46.5Al2Cr1.8Nb-(W, B) alloy via pulse current auxiliary isothermal forging (PCIF). The starting material composed of near gamma (NG) microstructure was fabricated by adopting pre-alloyed powders via hot pressing sintering (HPS) at 1300 °C. Isothermal compression tests were conducted at a strain rate range of 0.001–0.1 s−1 and a temperature range of 1125–1275 °C to establish the constitutive model and processing map. The optimal hot deformation parameters were successfully determined (in a strain rate range of 10−3–2.5 × 10−3 s−1 and temperature range of 1130–1180 °C) based on the hot processing map and microstructure observation. Accordingly, an as-forged TiAl based alloy without cracks was successfully fabricated by PCIF processing at 1175 °C with a nominal strain rate of 10−3 s−1. Microstructure observation indicated that complete dynamic recrystallization (DRX) and phase transformation of γ→α2 occurred during the PCIF process. The elongation of as-forged alloy was 136%, possessing a good secondary hot workability, while the sintered alloy was only 66% when tested at 900 °C with a strain rate of 2 × 10−4 s−1.

갱년기증후군 환자의 안면홍조 증상과 맥 에너지와의 상관성 연구

갱년기증후군 환자의 안면홍조 증상과 맥 에너지와의 상관성 연구

Hamiltonian Monte Carlo algorithm for the characterization of hydraulic conductivity from the heat tracing data

Estimating spatial distributions of the hydraulic conductivity in heterogeneous aquifers has always been an important and challenging task in hydrology. Generally, the hydraulic conductivity field is determined from hydraulic head or pressure measurements. In the present study, we propose to use temperature data as source of information for characterizing the spatial distributions of the hydraulic conductivity field. In this way, we performed a laboratory sandbox experiment with the aim of imaging the heterogeneities of the hydraulic conductivity field from thermal monitoring. During the laboratory experiment, we injected a hot water pulse, which induces a heat plume motion into the sandbox. The induced plume was followed by a set of thermocouples placed in the sandbox. After the temperature data acquisition, we performed a hydraulic tomography using the stochastic Hybrid Monte Carlo approach, also called the Hamiltonian Monte Carlo (HMC) algorithm to invert the temperature data. This algorithm is based on a combination of the Metropolis Monte Carlo method and the Hamiltonian dynamics approach. The parameterization of the inverse problem was done with the Karhunen-Loève (KL) expansion to reduce the dimensionality of the unknown parameters. Our approach has provided successful reconstruction of the hydraulic conductivity field with low computational effort.

Miocene uplift of the NE Greenland margin linked to plate tectonics: Seismic evidence from the Greenland Fracture Zone, NE Atlantic

Tectonic models predict that, following breakup, rift margins undergo only decaying thermal subsidence during their post-rift evolution. However, post-breakup stratigraphy beneath the NE Atlantic shelves shows evidence of regional-scale unconformities, commonly cited as outer margin responses to inner margin episodic uplift, including the formation of coastal mountains. The origin of these events remains enigmatic. We present a seismic reflection study from the Greenland Fracture Zone – East Greenland Ridge (GFZ-EGR) and the NE Greenland shelf. We doc- ument a regional intra-Miocene seismic unconformity (IMU), which marks the termination of syn-rift deposition in the deep-sea basins and onset of: (i) thermo-mechanical coupling across the GFZ, (ii) basin compression, and (iii) contourite deposition, north of the EGR. The onset of coupling across the GFZ is constrained by results of 2-D flexural backstripping. We explain the thermo-mechanical coupling and the deposition of contourites by the forma- tion of a continuous plate boundary along the Mohns and Knipovich ridges, leading to an accelerated widening of the Fram Strait. We demonstrate that the IMU event is linked to onset of uplift and massive shelf-progradation on the NE Greenland margin. Given an estimated middle-to-late Miocene (ca. 15-10 Ma) age of the IMU, we speculate that the event is synchronous with uplift of the East and West Greenland margins. The correlation between margin uplift and plate-motion changes further indicates that the uplift was triggered by plate tectonic forces, induced perhaps by a change in the Iceland plume (a hot pulse) and/or by changes in intra-plate stresses related to global tectonics.

Consolidation of W–Ta composites: Hot isostatic pressing and spark and pulse plasma sintering

Composites consisting of tantalum fiber/powder dispersed in a nanostructured W matrix have been consolidated by spark and pulse plasma sintering as well as by hot isostatic pressing. The microstructural observations revealed that the tungsten–tantalum fiber composites consolidated by hot isostatic pressing and pulse plasma sintering presented a continuous layer of Ta2O5 phase at the W/Ta interfaces, while the samples consolidated by spark plasma sintering evidenced a Ta+Ta2O5 eutectic mixture due to the higher temperature of this consolidation process. Similar results have been obtained for the tungsten–tantalum powder composites. A (W, Ta) solid solution was detected around the prior nanostructured W particles in tungsten–tantalum powder composites consolidated by spark and pulse plasma sintering. Higher densifications were obtained for composites consolidated by hot isostatic pressing and pulse plasma sintering.

Core-Shell Fine Structure of FeNi Magnetic Nanoparticles Produced by Electrical Explosion of Wire

Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">45</sub> Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">55</sub> magnetic nanoparticles (MNPs) were fabricated by electric explosion of wire. In order to reduce the pyrophoricity of the MNPs, oxygen passivation was performed leading to the creation of the surface barrier layer. The surface features of MNPs are important for the development of MNPs containing composites (polymer/MNPs microwave absorbers or composites for power electronic devices). X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy and X-ray photoelectronic spectroscopy (XPS) were used for structural characterization. XPS analysis of the samples was conducted varying the electron exit angle with respect to the surface. The main phase is the FeNi fcc metallic core and the barrier layer is an iron–nickel NiFe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> oxide with a thickness of 2–6 nm. Small toroidal cores of 1.5 cm in diameter were prepared by hot pulse pressing. Their structure was studied by XRD, SEM–EDX techniques. The magnetic properties of the cores were measured using double coil winding. Obtained materials are interesting for power and electronic applications.

In vitro Studies of the Antibody Response: Antibodies of Different Specificity are Made in Different Populations of Cells.

In vitro Studies of the Antibody Response: Antibodies of Different Specificity are Made in Different Populations of Cells.

Renewed melting at the abandoned Húnafloí Rift, northern Iceland, caused by plume pulsing

The abandoned Húnafloí Rift (HR), near Skagi in northern Iceland, provides an opportunity to investigate how relocation of an oceanic spreading ridge influences melt generation. Melting recommenced beneath HR several million years after spreading ceased at 7–4 Ma. Both the older (pre-HR abandonment) and younger (post-abandonment) lavas are tholeiitic basalts with high Fe–Ti and enriched incompatible trace element compositions. The HR lavas are compositionally similar to modern lavas from central Iceland (above the Iceland Plume conduit) and the Eastern Volcanic Zone (a propagating rift). Although older and younger HR lavas are compositionally similar, geological and geophysical observations indicate different mantle melting conditions. For the older lavas, a plume migration reconstruction suggests that the combination of incompatible trace element enrichment and crustal thickness of ∼25 km can be explained by plume-driven upwelling, a scenario similar to central Iceland at present. The smaller volume of the younger HR lavas (<1 km melt thickness) and their greater distance from the plume centre argues against plume-driven upwelling to explain their enrichment. Rare earth element inversion modelling indicates that the younger lavas come from reactivation of the deepest part of the melting region beneath HR. We suggest that the base of the HR melting region was reactivated when a pulse of unusually hot asthenosphere, known to be producing unusually thick crust ∼700 km away from the plume centre today, passed laterally beneath the HR at ∼3 Ma. A thermal and kinematic ridge–plume interaction model indicates that this scenario can explain both the volume and composition of the younger Skagi lavas, provided that a small amount of decompression occurs. The decompression may result either from extension or from buoyancy-driven upwelling of hot mantle beneath the relatively thin lithosphere of the abandoned HR. The hypothesis that a hot plume pulse caused the younger HR lavas is significant not only as an example of interaction between mid-ocean ridge melting and time-dependent mantle convection, but also because this same hot pulse may have subsequently helped promote intensification of the Northern Hemisphere Glaciation when it uplifted the oceanic gateways either side of Iceland.

Characterization of the volatile profile of Brazilian Merlot wines through comprehensive two dimensional gas chromatography time-of-flight mass spectrometric detection

Wine aroma is an important characteristic and may be related to certain specific parameters, such as raw material and production process. The complexity of Merlot wine aroma was considered suitable for comprehensive two-dimensional gas chromatography (GC×GC), as this technique offers superior performance when compared to one-dimensional gas chromatography (1D-GC). The profile of volatile compounds of Merlot wine was, for the first time, qualitatively analyzed by HS-SPME-GC×GC with a time-of-flight mass spectrometric detector (TOFMS), resulting in 179 compounds tentatively identified by comparison of experimental GC×GC retention indices and mass spectra with literature 1D-GC data and 155 compounds tentatively identified only by mass spectra comparison. A set of GC×GC experimental retention indices was also, for the first time, presented for a specific inverse set of columns. Esters were present in higher number (94), followed by alcohols (80), ketones (29), acids (29), aldehydes (23), terpenes (23), lactones (16), furans (14), sulfur compounds (9), phenols (7), pyrroles (5), C13-norisoprenoids (3), and pyrans (2). GC×GC/TOFMS parameters were improved and optimal conditions were: a polar (polyethylene glycol)/medium polar (50% phenyl 50% dimethyl arylene siloxane) column set, oven temperature offset of 10°C, 7s as modulation period and 1.4s of hot pulse duration. Co-elutions came up to 138 compounds in 1D and some of them were resolved in 2D. Among the co-eluted compounds, thirty-three volatiles co-eluted in both 1D and 2D and their tentative identification was possible only due to spectral deconvolution. Some compounds that might have important contribution to aroma notes were included in these superimposed peaks. Structurally organized distribution of compounds in the 2D space was observed for esters, aldehydes and ketones, alcohols, thiols, lactones, acids and also inside subgroups, as occurred with esters and alcohols. The Fischer Ratio was useful for establishing the analytes responsible for the main differences between Merlot and non-Merlot wines. Differentiation among Merlot wines and wines of other grape varieties were mainly perceived through the following components: ethyl dodecanoate, 1-hexanol, ethyl nonanoate, ethyl hexanoate, ethyl decanoate, dehydro-2-methyl-3(2H)thiophenone, 3-methyl butanoic acid, ethyl tetradecanoate, methyl octanoate, 1,4 butanediol, and 6-methyloctan-1-ol.

Identification of petroleum aromatic fraction by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry

Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS) is commercially available in the 1990s, with the characteristics of large peak capacity, high resolution, high sensitivity, etc. However, its application to the petroleum and geological analyses is just emerging in China and overseas. In this research, the analytical method for petroleum aromatic fraction using GC×GC-TOFMS is set up, via the choice of the column system and optimization of setting parameters, such as temperature programming, modulation time, hot pulse time, flow rate of carrier gas, data acquisition rate and data processing. The results indicate that different polar compounds of aromatic fraction distribute as bands on structured GC×GC chromatogram. Within each band, homologous compounds appear as a roof-tile structure based on the number of substituent residues. The aromatic compounds are identified and characterized according to the GC×GC chromatogram and mass spectra. According to the polarity and the number of rings, aromatic compounds are spatially present on one chromatogram, which directly reflects the distribution characteristics of complex compounds of aromatic hydrocarbons. In addition, quantitative analysis is favored as some overlapped peaks on traditional GC-MS chromatogram have been separated completely on GC×GC. Some heterocyclic atom aromatic compounds at trace level can be clearly identified using this method, for polarity differences from other interfered aromatic compounds. The development of this method and chromatogram recognition offer petroleum geologists a practical example for the application performance of GC×GC-TOFMS.

Production, properties, and erosion characteristics of B4C−Al composite materials

The paper examines the phase composition, structure, and erosion properties of B4C–Al composite materials produced by hot pulse pressing. It is shown that powder components actively interact to form new phases during pressing, TiB2 and AlB12 being the main phases. The erosion properties of the composites are greatly dependent on the composition of powder mixtures and compaction temperature. The structural features of the composites, namely the nanosized secondary phases at B4C grain boundaries, intensify the anode mass transfer to the titanium substrate and the formation of a protective coating up to 50 μm thick. The microhardness of this coating is about 40 GPa and its wear resistance is threefold higher than that of the substrate material.

Optimization of separation and detection conditions for comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry analysis of polychlorinated dibenzo- p-dioxins and dibenzofurans

The 2,3,7,8-substituted polychlorinated dibenzo- p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are among the most toxic compounds known, and several sources of exposure to these chemicals should be monitored to protect human and environmental health. The current predominant method of analysis is too expensive and cumbersome, and comprehensive two-dimensional GC coupled to time-of-flight mass spectrometry (GC × GC–TOF-MS) has the potential to lower the costs and speed analysis of PCDD/Fs. In this study, GC × GC–TOF parameters were evaluated and optimized to yield complete separation of the 17 most important PCDD/F congeners from polychlorinated biphenyls (PCBs) interferences, and to attain the lowest detection limits. The optimization study entailed evaluation of oven temperature programs, column flow rates, ion source temperatures, electron ionization energy, data acquisition rate, and various GC × GC parameters, including modulation period, modulator temperature offset and hot pulse duration. After optimization, all 17 PCDD/Fs were separated in <60 min, and in particular, the critical pair of 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) and pentachlorobiphenyl congener CB126 did not co-elute chromatographically. Accurate identification and determination of all analytes could be made using their deconvoluted full mass spectra. In GC × GC, the modulation period and start time were the most important factors that affected sensitivity and selectivity for the analysis of the PCDD/Fs. The modulation period should be ≤4 s to preserve separations achieved in one-dimensional GC, and the modulation start time was important to achieve one large slice and two smaller symmetrical slices of TCDD to maximize its detection sensitivity. After optimization, the method could identify 0.25 pg of TCDD with standard injection from its full mass spectrum.

An improved method to identify BAC clones using pooled overgos

Hybridization using overgo probes is an established approach for screening arrayed bacterial artificial chromosome (BAC) libraries. We have improved the use of overgos by increasing the yield of positive clones using reduced levels of radioisotopes and enzyme. The strategy involves labeling with all four radiolabeled nucleotides in a hot pulse followed by a cold nucleotide chase and then extending the exposure time to compensate for reduced specific activity of the probes. The resulting cost savings and reduced human exposure to radiation make the use of highly pooled overgo probes a more attractive approach for screening of BAC libraries from organisms with large genomes.

The role of shock waves in expansion tube accelerators

Simulations are combined with laboratory measurements to show the important role of shock waves in a popular physics demonstration, the “ping pong cannon.” The simulation and measurements confirm a developing shock wave that reflects from the end of the closed tube and approaching ball and the eventual formation of a transient localized pressure build-up near the exit tape barrier. This 2atm burst of pressure peaks within a few microseconds of the ball’s arrival, resulting from the combination of near ambient gas density and shock heating to about 1200K. Pulsed schlieren images beyond the exit confirm the sequence of internally reflected shock waves and the intense, hot air pressure pulse that explosively removes the exit tape just prior to the ball arrival.

Hot zones evolution and dynamics in heterogeneous catalytic systems.

Stationary and complex moving hot regions formed for temperatures close to the extinction temperature of uniformly ignited states of several catalytic systems, such as thin rings and hollow cylinders, a thin radial flow reactor (RFR) and a shallow packed bed. IR imaging revealed that the hot and cold regions (temperature difference of the order of 100 degrees C) were separated by a sharp (about 3 mm wide) temperature front. The transition from the branch of uniformly ignited to the states with a hot region was usually supercritical. In some experiments a disjoint branch of states with hot regions existed and two qualitatively different states with hot zones existed under the same operating conditions. A very intricate periodic motion of a hot zone was observed in a shallow packed bed reactor. For example, Fig. 16 shows a hot zone which splits and later coalesces several times during the long (14 h) period. Hot pulse motions were observed on a single catalytic pellet. These were caused by global coupling between the surface reaction rate and the ambient reactant concentration and the inherent nonuniformity of the catalytic activity. It is not yet clear what rate processes generate the transversal hot zones in uniform packed bed reactors. (c) 2002 American Institute of Physics.

Mechanical and magnetic properties of Ni-Co dispersed Al2O3 nanocomposites

Effects of the fabrication processing on the microstructure and properties of composites were investigated. High-density Ni-Co dispersed-Al2O3 (Al2O3/Ni-Co) composites were obtained by hydrogen reduction and consolidated using hot pressing and pulse electric current sintering (PECS) of Al2O3, Ni(NO3)2·6H2O and Co(NO3)2·6H2O powder mixtures. Microstructural investigations of the hot-pressed composite fabricated using again wet/dry ball-milled powder mixture after calcination revealed that fine Ni-Co particles, about 145 nm in diameter, dispersed homogeneously at the matrix grain boundaries. In particular, fine microstructure of dispersion with the average size of 90 nm was realized for the specimen consolidated by PECS method. High strength of over 1 GPa and hardness of 19 GPa were measured for the nanocomposites prepared from the again ball-milled powder mixture. The ferromagnetism of nano-sized Ni-Co contributes to the magnetic properties of the composites. A change in the coercive force with dispersion size was observed. Also, the extent of magnetic response by an applied stress was strongly influenced by the size of Ni-Co particles. The relations between microstructure and mechanical as well as magnetic properties are discussed.

Hydrocarbon-bearing fluid inclusions in the Drau Range (Eastern Alps, Austria): implications for the genesis of Bleiberg-type Pb-Zn deposits

Hydrocarbons in ore minerals of Bleiberg-type Pb-Zn deposits and in authigenic quartz of the Drau Range (Eastern Alps) have been analysed by bulk-sample gas chromatography and fluorescence microscopy. Microthermometric data and the molecular composition of the hydrocarbons indicate a hot (120° to 130°C) pulse of migrating condensate-like hydrocarbons within Late Triassic sediments during Middle Cretaceous to Early Tertiary times. The molecular composition of hydrocarbons enclosed in authigenic quartz corresponds to the composition of hydrocarbons trapped in Bleiberg-type ore minerals, therefore a common fluid source is assumed. The hydrocarbons possibly played an important role as reducing agents in the late stage of sulfide precipitation.