The Synoptic Characteristics, Causes, and Mechanisms of Kahlaa Tornado in Iraq on 14th April 2016

In this study, an analysis of the synoptic characteristics, causes and mechanisms of Kahlaa tornado event was carried out. This tornado occurred on 10:30 UTC (1:30 pm Iraq Local Time) on 14 April 2016 to the north of Kahlaa town in Maysan governorate. We analyzed surface and upper charts, weather conditions, the damage indices, the dynamical features and the instability of the tornado. The analysis showed that there was a low pressure system which was an extension of the Monsoon low in addition to a supercell thunderstorm and a jet stream aloft. The cold trough and high relative vorticity at 500 hPa level, the humid warm wind blowing from the south and the dry cold wind from the north contributed to the initiation of the tornado. According to the damage amount, Kahlaa tornado can be classified as EF2 degree (considerable) on Enhanced Fujita scale. Three indices were calculated to estimate the instability of the tornado. The values of the convective available potential energy (CAPE), K-index, and lifted index were (≥2500 J/kg), (35.3 oC), and (-7), respectively. All these indices confirmed the instability required to form severe thunderstorm essential to tornado formation. Although the forecasting of tornadoes occurrence is difficult, there would be indications that may lead to expect of occurrence. These may include the availability of moisture, heat, and significant wind direction changes with altitude. However, the vital factors were the existence of high instability and a supercell thunderstorm.

Influence of cohesion on drifting snow investigated in cold wind-tunnel

<p>Aeolian transport of particles occurs in many geophysical contexts such as wind-blown sand or snow drift and is governed by a myriad of physical mechanisms. Most of drifting particles are transported within a saltation layer and has been largely studied for cohesionless particles whether for snow or for sand. Thus, the theoretical description of aeolian transport has been greatly improved for the last decades. In contrast cohesive particles-air system have received much less attention and there remain many important physical issues to be addressed.  </p><p>In the present study, the characteristics of drifting cohesive snow phenomena is investigated experimentally. Several wind tunnel experiments were carried out in the Cryopsheric Environment simulator at Shinjo (Sato et al., 2001). Spatial distribution of wind velocity and the mass flux of drifting snow were measured simultaneously by an ultrasonic anemometer and a snow particle counter. Compacted snow was sifted on the floor and left for a determined duration time to become cohesive by sintering. Two kinds of snow beds with different compression hardness were used (“hard snow” with a compression hardness of about 60 kPa and “semi hard snow” with a compression hardness of about 30 kPa). Wind tunnel velocity varied from 7 m/s to 15 m/s. Moreover steady snow drifting can be produced by seeding snow particles at a constant rate at the upwind of the test section.</p><p>It was shown that :</p><p>- on hard snow cover, aerodynamic entrainment does not occur and saltating particles from the seeder just rebounded without splashing particles composing the snow surface (Kosugi et al.,2004). At a given transport rate, the characteristic decay length lν,which can be seen as an estimation of the height of the saltating layer, exhibits a quadratic dependence with the air friction speed, u*. It is in agreement with results obtained by Ho (2011) with saltating sand on non-erodible bed. More surprisingly, lν increases with snow particles diameter, which means that restitution coefficient over hard snow cover also increases with snow particles diameters.</p><p> - On loose snow cover, without seeder, data analysis from  Sugiura et al. (1998), shows that lv is proportional to u* to the power 1.4. This results therefore supports the idea that cohesionless snow doesn’t exist: on erodible sand bed configuration, the decay length is invariant (Ho, 2012).</p><p>-on semi hard snow cover, without seeder, the inter-particle cohesion makes the transport unsteady and spatially inhomogeneous. lv is proportional to u* to the power 1.6. It is therefore an intermediate case between “loose” and “hard “snow. Restitution coefficient on semi-hard snow is higher than on loose snow cover but smaller than on hard snow cover.  Particles are mainly lifted through aerodynamic entrainment so that saturation length is not obtained in the wind-tunnel : the transport rate  is two orders of magnitude lower than   the maximum transport rate observed for loose snow.</p><p>-on semi hard snow cover, with seeder, the drifting snow flux dramatically increases, even for low wind speed, leading sometimes to snow cover vanish. Experimental results provide evidence that impacting particles are efficient to lift cohesive snow particles : the transport rate increases to nearly 10.</p>

ABOUT THE SYNTACTIC CONSTRUCTIONS AND FEATURES OF THE APHORISMS USED IN AZERBAIJAN LANGUAGE

The purpose of the article is to study the syntactic features of the aphorisms of the Azerbaijani language through the definition of the concept of syntactic constructions in the Azerbaijani aphorisms. Simple and complex sentences involved in the formation of aphorisms are studied using specific examples. Literary texts in the Azerbaijani language have been selected as a research method, the concept has been formed on the basis of an analysis of scientific and theoretical approaches and ideas regarding aphorisms in modern linguistics. It is determined that in the formation of aphorisms, various forms are active, which are included in the concept of syntactic construction. Syntactic constructions are formed mainly on the basis of phrases and types of sentences and their relationships. Their diversity also enriches the aphorisms of the given language. It has been revealed that syntactic constructions are simple and complex sentences and phrases. Analysis of aphorisms allows one to determine both sentences and phrases. The study of the syntactic features of Azerbaijani aphorisms is very important from the point of view of determining the ways of language development. It has been proven that the main sources for the formation and enrichment of aphorisms are certain types of sentences. The study has yielded a number of interesting scientific results. The structural analysis of Azerbaijani aphorisms has revealed the problem of using metaphors. The metaphorization of being is a property of the human mind, which is always prone to imagery, and is one of the most important and necessary categories of language. Literary language is a figurative language where the word is not limited to the expression of thought and is actively used in the figurative description of objective reality. Here the word acts as a means of creating an image in the literary language, giving a subjective assessment of the ongoing processes, expressing subtle and deep feelings, forming the reader�s aesthetic taste, as well as emotionally influencing him. One of the meanings of each polysemantic word is real, and the rest are derivatives, secondary or figurative. For example, if we think of the word �cold� in the expression �cold wind� as a word with a real meaning, then it is clear that the word �cold� with the same content in the combinations �cold attitude� or �cold gaze� has a more figurative meaning ...

High resolution X-ray spectroscopy of Supergiant HMXB 4U1700−37 during the compact object eclipse.

We present an analysis of the first observation of the iconic High Mass X-ray Binary 4U 1700−37 with the Chandra High Energy Transmission Gratings during an X-ray eclipse. The goal of the observation was to study the structure/physical conditions in the clumpy stellar wind through high resolution spectroscopy. We find that: a) emission line brightness from K shell transitions, corresponding to near neutral species, directly correlates with continuum illumination. However, these lines do not greatly diminish during eclipse. This is readily explained if fluorescence Kα emission comes from the bulk of the wind. b) The highly ionised Fe xxv and Fe xxvi Lyα diminish during eclipse. Thus, they must be produced in the vicinity of the compact object where log ξ > 3. c) to describe the emission line spectrum, the sum of two self consistent photo ionisation models with low ionisation (log ξ ∼ −1) and high ionisation (log ξ ∼ 2.4) is required. From their emission measures, the clump-to-interclump density ratio can be estimated to be nc/ni ∼ 300. To fit the complex He-like Si xiii profile, the plasma requires a broadening with vbulk ∼ 840 km s−1. Reproducing the observed r ≈ f line fluxes requires the addition of a third collisionally ionised plasma. d) Emission lines widths appear unresolved at the hetg gratings resolution with exception of Silicon. There is no clear radial segregation between (quasi)neutral and ionised species, consistent with cold wind clumps interspersed in a hot rarefied interclump medium.

Chandra spectral measurements of the O supergiant ζ Puppis indicate a surprising increase in the wind mass-loss rate over 18 yr

ABSTRACT New long Chandra grating observations of the O supergiant ζ Pup show not only a brightening of the X-ray emission line flux of 13 per cent in the 18 yr since Chandra’s first observing cycle, but also clear evidence – at more than 4σ significance – of increased wind absorption signatures in its Doppler-broadened line profiles. We demonstrate this with non-parametric analysis of the profiles as well as Gaussian fitting and then use line-profile model fitting to derive a mass-loss rate of 2.47 ± 0.09 × 10−6${\mathrm{M_{\odot }~{\mathrm{y}r^{-1}}}}$, which is a 40 per cent increase over the value obtained from the cycle 1 data. The increase in the individual emission line fluxes is greater for short-wavelength lines than long-wavelength lines, as would be expected if a uniform increase in line emission is accompanied by an increase in the wavelength-dependent absorption by the cold wind in which the shock-heated plasma is embedded.

Aspergillosis infection over 20 years: a case report of probable vascular invasion in central nervous system

Background Aspergillosis infection of central nervous system (CNS) is rare and fatal. Diagnosis of invasive aspergillosis remains difficult. Aspergillosis of CNS can be an acute, subacute, or chronic onset, and the longest course of the disease was currently reported to be 4 years. Here, we report a case with recurrent headache over 20 years. Case presentation A 54-year-old man was admitted to our neurological disease ward due to intermittent throbbing headache lasting for more than 20 years that had grown notably worse over the past week. The headache was localized to the side of his head blown by a cold wind. He also experienced nausea and vomiting when the headache became severe. The headache usually lasted for 3–4 h after he was blown by the cold wind, though he had no fever. The neurological examination was normal. Magnetic resonance imaging (MRI) of the brain was negative for parenchymal and meningeal lesions. However, the case had increased intracranial pressure (ICP), and elevated protein level in the cerebrospinal fluid (CSF). Aspergillus fumigatus was found in CSF by nanopore targeted sequencing (NTS) and in blood by enzyme-linked immunosorbent assay (ELISA). Aspergillus fumigatus-specific antibody IgG was 104.62 AU/mL, aspergillus galactomannan (GM) antigen was 3.27 μg/L, D-dimer was 3.25 mg/L and fibrinogen degradation product was 11.50 mg/L, which were markedly higher than the normal levels. The patient was prescribed by voriconazole. After the treatment of 14 days, the ICP, CSF protein level, Aspergillus fumigatus-specific antibody IgG, GM antigen, D-dimer and fibrinogen degradation product returned normal. Aspergillus was disappeared by NTS test of CSF. His headache has never occurred again after blowing by a cold wind. Conclusions This report reveals that aspergillosis infection of CNS can last for more than 20 years and the major symptom is only intermittent throbbing headache in an immunocompetent patient. Vascular invasion is probably the mechanism of headache in our case with CNS aspergillosis infection. Performing high-throughput gene sequencing technology in CSF is important when the pathogen is not determined for the patients with suspected CNS infection.

“A Cold Wind A’ Blowin’ ” (1991–2019)

During the period covered at the beginning of this chapter (the early 1990s), WAMU-FM and the Birchmere both still featured bluegrass; by the chapter’s close, in the contemporary period, this powerful radio station had completely transitioned to a news and talk format and the Birchmere only occasionally booked this genre. The sheer number of bands and venues diminished noticeably as did the general interest in bluegrass. The shrinkage of bluegrass programming on WAMU-FM was gradual and deliberate, occurring over some dozen years. The local bluegrass community vehemently protest, but to no avail. However, the existence of the WAMU-FM spin-off bluegrasscountry.org and the formation of DC Bluegrass Union reflect the existence of the ongoing, though diminished, local bluegrass community.