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

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)

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

Връзката между носната обструкция и енурезис ноктурна – описание на клиничен случай и преглед на литературата

Представяме клиничен случай на 20-годишен пациент с енурезис ноктурна и носна обструкция, дължаща се на девиация на носната преграда, който беше опериран в нашата клиника. След направената септопластика в продължение на деветмесечно наблюдение са преустановени напълно нощните напикавания на пациента. Известна и описана в литературата е връзката между първичната енурезис ноктурна и обструктивната сънна апнея при децата – сънната апнея е често срещана при децата с нощно напикаване и първичното нощно напикаване е чест симптом на такъв обструктивен синдром. Липсват категорични данни за връзката между изолираното нарушено носно дишане без сънна апнея и първичната енурезис ноктурна. Обсъждане на ролята на носната обструкция при случаите на нощно напикаване, които не се повлияват от приложените лечения в детска и по-късна възраст

Case Report of Advanced Juvenile Nasopharyngeal Angiofibroma with Cavernous Sinus Involvement: Advantages of Advanced Radiotherapy Thechnique Volumetric Modulated Arc Therapy

Objectives: In very advance unresectable stages Juvenile nasopharyngeal angiofibroma (JNA)radiotherapy is treatment of choice. Usually JNA is in close proximity to different organ at risk, which necessitates accurate and precise radiation delivery. Series reported the application of IMRT (Intensity Modulated Radiotherapy) with good sparing of organ at risk, but the literature search found no report on VMAT (Volumetric Modulated Arc Therapy) treatment in case of JNA.Clinical case: The present publication report for first time a patient irradiated with VMAT and IGRT (Image guided radiotherapy) for JNA. The stage of the tumor based on CT and MRI was IIIB according to Radkovsi with cavernous sinus invasion. Moderate total radiation dose 36 Gy in 1.8 Gy per fraction was delivered. No early and late toxicity was recorded. The patient is followed up every six months and persistent residual tumor on MRI was seen, but no bleeding onphysical exam. At one year follow up this is accepted as good local control.Conclusion: VMAT and IGRT could be safely applied with reduction of the radiation dose at organ of risk. VMAT is promising in the treatment of juvenile angiofibroma with advantages over conventional radiotherapy, but as this is case report of only one patient, further experience with VMAT is needed in JN