Combustion theory for liquids with a free surface. 3: Special problems

Two special problems concerning the combustion of liquids with a free surface, i.e., flame quenching during the mixing of a burning liquid inside a container and liquid burnout from a porous layer, are analyzed using a quasi-one-dimensional model. The critical parameters corresponding to the quenching of a burning fluid with a free surface are determined. Determinations are also made of the limiting pressure gradients corresponding to the transition from the combustion mode where the liquid evaporates from the surface of a porous layer to the mode where the phase transition surface lies inside the porous layer

Поворот 1900 года в логике Бертрана Рассела, возникновение парадокс а и сп особ его разрешения

Russell’s initial project in philosophy (1898) was to make mathematics rigorous reducing it to logic. Before August 1900, however, Russell’s logic was nothing but mereology. First, his acquaintance with Peano’s ideas in August 1900 led him to discard the part-whole logic and accept a kind of intensional predicate logic instead. Among other things, the predicate logic helped Russell embrace a technique of treating the paradox of infinite numbers with the help of a singular concept, which he called “denoting phrase”. Unfortunately, a new paradox emerged soon: that of classes. The main contention of this paper is that Russell’s new conception only transferred the paradox of infinity from the realm of infinite numbers to that of class-inclusion. Russell’s longelaborated solution to his paradox developed between 1905 and 1908 was nothing but to set aside of some of the ideas he adopted with his turn of August 1900: (i) With the Theory of Descriptions, he reintroduced the complexes we are acquainted with in logic. In this way, he partly restored the pre-August 1900 mereology of complexes and simples. (ii) The elimination of classes, with the help of the “substitutional theory”, and of propositions, by means of the Multiple Relation Theory of Judgment, completed this process.Исходный философский проект Рассела (1898) состоял в том, чтобы сделать математику строгой, сведя её к логике. До августа 1900 г., однако, логика Рассела представляла собой не более чем мереологию. В августе 1900 г. он познакомился с идеями Пеано, что привело его к отказу от логики части и целого и принятию вместо неё своего рода интенсиональной логики предикатов. Среди прочего, логика предикатов помогла Расселу найти способ справиться с парадоксом бесконечных чисел с помощью одного-единственного понятия — того, что он назвал «обозначающим выражением». К сожалению, вскоре обнаружился новый парадокс, на этот раз связанный с классами. Основной тезис данной статьи состоит в том, что новая концепция Рассела лишь перенесла парадокс бесконечности из области бесконечных чисел в сферу отношений включения на множествах. Решение парадокса, над которым Рассел долго работал в период между 1905 и 1908 гг., заключалось не в чём ином, как в том, чтобы отказаться от некоторых идей, принятых им во время «поворота» в августе 1900 г. (i) В теории дескрипций была отчасти восстановлена мереология сложных и простых объектов в духе периода, предшествовавшего августу 1900 г. (ii) Элиминация классов посредством «подстановочной теории» и устранение пропозиций за счёт теории суждения как множественного отношения завершили этот процесс

Предимства и недостатъци на транспланти и имплантанти, използвани в уголемяващата ринопластика

Транспланти и импланти в ринохирургията се използват често, за да се реконструира поддържането структури за върха за нос, коригиране на седловиден нос, както и подобряване на функцията на носната клапа или форма на върха на носа. Уголемяващата ринопластика е била прилагана предимно при пациенти от жълтата раса, африканци или афроамериканци. Днес, с бързото развитие на пластичната и естетична хирургия, уголемяващата ринопластика е придобила голяма популярност в Азия. Целта на нашата статия е да представим световния опит по този проблем

Elevated surface chlorophyll associated with natural oil seeps in the Gulf of Mexico

Natural hydrocarbon seeps occur on the sea floor along continental margins, and account for up to 47% of the oil released into the oceans. Hydrocarbon seeps are known to support local benthic productivity, but little is known about their impact on photosynthetic organisms in the overlying water column. Here we present observations with high temporal and spatial resolution of chlorophyll concentrations in the northern Gulf of Mexico using in situ and shipboard flow-through fluorescence measurements from May to July 2012, as well as an analysis of ocean-colour satellite images from 1997 to 2007. All three methods reveal elevated chlorophyll concentrations in waters influenced by natural hydrocarbon seeps. Temperature and nutrient profiles above seep sites suggest that nutrient-rich water upwells from depth, which may facilitate phytoplankton growth and thus support the higher chlorophyll concentrations observed. Because upwelling occurs at natural seep locations around the world, we conclude that offshore hydrocarbon seeps, and perhaps other types of deep ocean vents and seeps at depths exceeding 1,000 m, may influence biogeochemistry and productivity of the overlying water column

Understanding long-term carbon cycle trends: The late Paleocene through the early Eocene

[1] The late Paleocene to the early Eocene (~58–52 Ma) was marked by significant changes in global climate and carbon cycling. The evidence for these changes includes stable isotope records that reveal prominent decreases in δ18O and δ13C, suggesting a rise in Earth's surface temperature (~4°C) and a drop in net carbon output from the ocean and atmosphere. Concurrently, deep-sea carbonate records at several sites indicate a deepening of the calcite compensation depth (CCD). Here we investigate possible causes (e.g., increased volcanic degassing or decreased net organic burial) for these observations, but from a new perspective. The basic model employed is a modified version of GEOCARB III. However, we have coupled this well-known geochemical model to LOSCAR (Long-term Ocean-atmosphere Sediment CArbon cycle Reservoir model), which enables simulation of seawater carbonate chemistry, the CCD, and ocean δ13C. We have also added a capacitor, in this case represented by gas hydrates, that can store and release13C-depleted carbon to and from the shallow geosphere over millions of years. We further consider accurate input data (e.g., δ13C of carbonate) on a currently accepted timescale that spans an interval much longer than the perturbation. Several different scenarios are investigated with the goal of consistency amongst inferred changes in temperature, the CCD, and surface ocean and deep ocean δ13C. The results strongly suggest that a decrease in net organic carbon burial drove carbon cycle changes during the late Paleocene and early Eocene, although an increase in volcanic activity might have contributed. Importantly, a drop in net organic carbon burial may represent increased oxidation of previously deposited organic carbon, such as stored in peat or gas hydrates. The model successfully recreates trends in Earth surface warming, as inferred from δ18O records, the CCD, and δ13C. At the moment, however, our coupled modeling effort cannot reproduce the magnitude of change in all these records collectively. Similar problems have arisen in simulations of short-term hyperthermal events during the early Paleogene (Paleocene-Eocene Thermal Maximum), suggesting one or more basic issues with data interpretation or geochemical modeling remain

Inventory of current EU paediatric vision and hearing screening programmes

Background: We examined the diversity in paediatric vision and hearing screening programmes in Europe. Methods: Themes relevant for comparison of screening programmes were derived from literature and used to compile three questionnaires on vision, hearing and public-health screening. Tests used, professions involved, age and frequency of testing seem to influence sensitivity, specificity and costs most. Questionnaires were sent to ophthalmologists, orthoptists, otolaryngologists and audiologists involved in paediatric screening in all EU fullmember, candidate and associate states. Answers were cross-checked. Results: Thirty-nine countries participated; 35 have a vision screening programme, 33 a nation-wide neonatal hearing screening programme. Visual acuity (VA) is measured in 35 countries, in 71% more than once. First measurement of VA varies from three to seven years of age, but is usually before the age of five. At age three and four picture charts, including Lea Hyvarinen are used most, in children over four Tumbling-E and Snellen. As first hearing screening test otoacoustic emission (OAE) is used most in healthy neonates, and auditory brainstem response (ABR) in premature newborns. The majority of hearing testing programmes are staged; children are referred after one to four abnormal tests. Vision screening is performed mostly by paediatricians, ophthalmologists or nurses. Funding is mostly by health insurance or state. Coverage was reported as >95% in half of countries, but reporting was often not first-hand. Conclusion: Largest differences were found in VA charts used (12), professions involved in vision screening (10), number of hearing screening tests before referral (1-4) and funding sources (8)

停留精巣の研究 第3報: 停留精巣患者における精巣内複合糖質の組織化学的研究

3～37歳の停留精巣患者23例の停留精巣および対側陰嚢内精巣において, 光顕組織化学的方法にて複合糖質の変化を観察し, さらに正常精巣組織と比較した.停留精巣精細管壁及び間質では, 正常精巣に比べ酸性ムコ多糖(精細管壁:コンドロイチン硫酸A及びC, 間質:コンドロイチン硫酸B)が減少し, 特に精細管壁において顕著であった.なお, 患側精細管上皮においては, 思春期前から思春期以後を通じ, グリコーゲン及びガラクトース含有量の減少が認められたThe complex carbohydrates in the undescended and contralateral scrotal testes of patients with cryptorchidism, were examined by light microscopic histochemical methods, in comparison with those of normal testes. In the undescended testes, histochemical reactions for acidic and neutral complex carbohydrates were apparently weaker than in the normal testes, especially pronounced in the seminiferous tubular walls. In the germinal and supporting cells of the undescended testes, the amount of galactose residues in the complex carbohydrates decreased from the prepubertal to post-pubertal periods. Periodic acid-Schiff reaction also revealed a decrease in the glycogen content in the germinal and supporting cells of the undescended testes from pre-pubertal to post-pubertal periods

Eagle syndrome – from symptom to diagnosis. Case report

Introduction: Eagle syndrome is a rare condition caused by elongation of the styloid process or ossification of the stylohyoid ligament. It’s named after Watt W. Eagle an otolaryngologist at Duke university, who described the first case in 1937. In the clinical presentation, we found different signs of syndrome – dysphagia, odynophagia, otalgia, foreign body sensation, facial pain, trismus, headache, increased salivation, and/or voice changes. The diagnosis of Eagle’s syndrome is based on an optimal medical history and physical examination. The most accurate imaging technique is the CT- scan. 3-D CT reconstruction of the neck specify the size of length of the styloid process (>3 mm) and the ossified stylohyoid ligament. The treatment includes conservative and surgical approach.Material and methods: We present a 65- years old female, in a good health condition, with the following complains: difficulty swallowing, foreign body sensation in the throat. The patient states that she had palpated cartilage in the right side in the area of the tonsillar fossa. The physical examination revealed no abnormal findings, but palpable right styloid process. We performed CT and 3-D CT reconstruction, which showed an elongation of styloid process on right side. Results: The patient refused the surgical treatment. The conservativetherapy includes the nonsteroidal anti- inflammatory medications.Conclusion: Eagle’s syndrome is a rare condition with vast differential diagnosis, vague symptomatology and ambiguous incidence and etiology. When we suggest the syndrome, the CT scan is the imaging method of choice for diagnosis. It shows the measurement of styloid process, the position in the neurovascular complex and the prepositions of damages. The treatment can be surgical or non-surgical depend on the size, position and surgical risk of the approac

The use of digital devices in the field of healthcare in Bulgaria

Abstract Background The opportunities that information and communication technologies provide in the field of healthcare are many and constantly growing. Thanks to them, consumers have access to health information, consultations and remote treatment and connection with medical centers. They help to improve health promotion activities, whose mission is to promote health as a core value. The aim of the present study is to explore the attitudes regarding the use of digital devices in the field of healthcare of Bulgarian population. Methods A direct anonymous survey was conducted among 356 respondents, randomly selected and with an average age of 38.26 ± 0.15 (110 men and 246 women). The study was conducted from October 2018 to April 2019. The data analysis was performed using the statistical software SPSS v.23.0. Results The results showed that 78.9% of respondents have used or are willing to use digital devices to search for and record health information. A statistical gender difference was found in the answer to the question of using a digital device for self-registration of information (χ2 = 28.6, P &amp;lt; 0.05), as women are more likely to do so. More than 75% of respondents are willing to share health information with a medical professional in real-time via the internet. Older people are more reserved and hesitant about providing health information to a state agency (66.7%). The smartphone and computer/laptop are among the most preferred digital modalities in the healthcare field, with men and younger respondents more likely to use digital devices in relation to their health (χ2=39.9, P &amp;lt; 0.05). Women are more critical about the use of information and communication technologies in healthcare (χ2=48.2, P &amp;lt; 0.05). Conclusions The present study found a positive attitude among all respondents towards the introduction of modern technologies in the healthcare field and the opportunity of remote contact with medical professionals, using personal digital devices. Key messages The opportunities that information and communication technologies provide in the field of healthcare are many and constantly growing. The aim of the present study is to explore the attitudes regarding the use of digital devices in the field of healthcare of Bulgarian population. </jats:sec