Исследование зон усталостного разрушения шнеков

Шнек - основной рабочий орган машин для переработки отходов - экструдеров. От качества его изготовления зависит производительность цеха и целостность корпуса машины. При переработке многокомпонентного сырья, которым является Refuse Derived Fuel - это общее название альтернативных видов топлива, получаемых при переработке отходов. В качестве сырья используется практически любой органический материал: целлюлоза, резина, пластик, кожа, дерево, пищевые заменители. В исследовании использован пример на базе работы с RDF-сырьем Мусороперерабатывающего комбината "Янино", Ленинградская область. Именно при работе с такими высокоабразивными отходами возникает необходимость многократно повышать ресурс шнеков за счет использования новых технологий обработки металлов, так как в составе данного сырья могут встречаться металлические компоненты и трудно размалываемые силикаты.Screw - the main working organ of machines for processing waste - extruders. From the quality of its production depends the productivity of the shop and the integrity of the machine body. When refining a multicomponent raw material, which is Refuse Derived Fuel - this is the general name for alternative fuels obtained from recycling. As raw material, almost any organic material is used: cellulose, rubber, plastic, leather, its substitutes. The study used an example based on work with RDF-raw materials of the Janino Refuse Processing Plant. Leningrad region. It is when working with such highly abrasive waste that it becomes necessary to increase the service life of screw augmentedly by using new processing technologies, since metal components and hard-to-break silicates can occur in the composition of this raw material

Algometry with a clothes peg compared to an electronic pressure algometer: a randomized cross-sectional study in pain patients

<p>Abstract</p> <p>Background</p> <p>Hypersensitivity of the central nervous system is widely present in pain patients and recognized as one of the determinants of chronic pain and disability. Electronic pressure algometry is often used to explore aspects of central hypersensitivity. We hypothesized that a simple pain provocation test with a clothes peg provides information on pain sensitivity that compares meaningfully to that obtained by a well-established electronic pressure algometer. "Clinically meaningful" was defined as a medium (r = 0.3-0.5) or high (r > 0.5) correlation coefficient according to Cohen's conventions.</p> <p>Methods</p> <p>We tested 157 in-patients with different pain types. A calibrated clothes peg was applied for 10 seconds and patients rated the pain intensity on a 0 to 10 numerical rating scale. Pressure pain detection threshold (PPdt) and pressure pain tolerance threshold (PPtt) were measured with a standard electronic algometer. Both methods were performed on both middle fingers and ear lobes. In a subgroup of 47 patients repeatability (test-retest reliability) was calculated.</p> <p>Results</p> <p>Clothes peg values correlated with PPdt values for finger testing with r = -0.54 and for earlobe testing with r = -0.55 (all p-values < 0.001). Clothes peg values also correlated with PPtt values for finger testing with r = -0.55 (p < 0.001). Test-retest reliability (repeatability) showed equally stable results for clothes peg algometry and the electronic algometer (all r-values > 0.89, all p-values < 0.001).</p> <p>Conclusions</p> <p>Information on pain sensitivity provided by a calibrated clothes peg and an established algometer correlate at a clinically meaningful level.</p

The effects of air velocity on the performance of pad evaporative cooling systems

The aim of this study is to determine the relationship that is found among the velocity of the air passing through the pad, the obtained decrease at the temperature of the air passing the pad and the cooling efficiency at the cellulose based evaporative cooling pad, and be of help to the people who designed and operate these systems. In this study, cellulose based evaporative cooling pad (CELdek R7060-15, Munters AB, Kista, Sweden) was used and the tests conducted were completed at 2 periods. Air velocities were determined as 0.5, 1.0 and 1.5 ms-1 at the first period, and 0.75, 1.25 and 1.75 ms-1 at the second period. The water flow rate at the air velocities, chosen for both periods, was selected as 4 Lmin-1m-2. As a result of the research, it was determined that it was not possible to make a mathematical connection among velocities of the air passing through the pad, obtained decrease at the temperature of the air passing the pad and the cooling efficiency. However, it can be said that the most appropriate air velocity for the pad used in the test should be higher than 0.5 ms-1 and lower than 1.5 ms-1. © 2011 Academic Journals

The influence of anaesthesia on CPSP development after carpal tunnel surgery

Background: Chronic postsurgical pain (CPSP) is a frequent adverse event after surgery. Although CPSP is much more acknowledged as an important complication in daily clinical practice, its etiology is still not sufficiently explored and demands further investigation. Recent studies revealed the role of the anaesthetic procedure as a possible risk factor of CPSP. The aim of this study was to investigate the influence of anaesthesia on the development of CPSP. Methods: A prospective, multicentric, observational study with a six-month follow-up was carried out. 48 patients completed the study within the study period. Pain intensities were recorded on the first postoperative day and after one, three and six months. After descriptive analysis of the data we took the normal distribution of the data for granted. Accordingly, non-parametric tests like the Mann-Whitney U test, the Chi-square test or the exact test after Fisher were used for statistical analysis. Results: Following carpal tunnel surgery 25% of the patients developed CPSP. 35% of them had general anaesthesia, whereas 17.9% received regional anaesthesia. Significant differences in pain intensity were evidenced. Patients with general anaesthesia reported stronger pain than patients with regional anaesthesia. The pain quality did not differ between the two study groups. Conclusion: Overall results showed an advantage of regional anaesthesia regarding the prevention of CPSP. Patients who underwent general anaesthesia suffered significantly more pain following a carpal tunnel surgery than patients with regional anaesthesia. Patients who had a general anaesthesia suffered from CPSP more often than those who had a regional anaesthesia. The anaesthetic procedure had no influence on the pain quality. However, more, larger and randomized studies are needed to establish the superiority of regional anaesthesia when it comes to preventing CPSP

Impact of preoperative pain on postoperative pain chronification. Six-month follow-up after urologic surgery

Background. We examined the influence of preoperative pain on postoperative pain chronification in urological patients. Methods. Pain was determined before operation, immediately afterwards and 3 or 6 months post-surgically. Acute and chronic pain was analysed in detail with regard to severity, grade of chronification and pain intensity. We also assessed patients with the Hospital Anxiety and Depression Scale. Results. Patients with preoperative pain reported postoperatively higher pain scores compared to patients without preoperative pain. Patients with higher Hospital Anxiety and Depression Scale scores reported higher pain scores for the first 7 days after the operation. Three months after surgery 51.2% of all patients and 6 months after surgery 1.2% of all patients reported about pain. Conclusion. Our results give evidence to the fact that preexisting pain prior to surgery has an influence on the postoperative pain course. To avoid chronification adequate therapy of the preexisting pain should be carried out

Технологические решения для строительства поисково-оценочной вертикальной скважины на целевой пласт Ю11-2 нефтяного месторождения

Выполнено обоснование профиля и конструкции скважины, определены глубины спуска обсадных колонн и их число, выбраны интервалы цементирования, рассчитаны диаметр проектной скважины и диаметры обсадных колонн и разработана схема обвязки устья скважины на нефтяном месторождении (Томской области Парабельского района).Justification of the profile and design of the well was carried out, the casing string descent depths and their number were determined, cementing intervals were selected, the diameter of the project well and the diameters of the casing strings were calculated, and a wellhead piping scheme was developed at an oil field (Tomsk Region, Parabel District)

Transformations from WISE to 2MASS, SDSS and BVI Photometric Systems: II. Transformation Equations for Red-Clump Stars

We present colour transformations for the conversion of Wide-Field Survey Explorer W1, W2, and W3 magnitudes to the Johnson-Cousins BVIc, Sloan Digital Sky Survey gri, and Two Micron All Sky Survey JHK(s) photometric systems, for red clump (RC) stars. RC stars were selected from the Third Radial Velocity Experiment Data Release. The apparent magnitudes were collected by matching the coordinates of this sample with different photometric catalogues. The final sample (355 RC stars) was used to obtain metallicity-dependent and free-of-metallicity transformations. These transformations combined with known absolute magnitudes at shorter wavelengths can be used in space density determinations for the Galactic (thin and thick) discs at distances larger than the ones evaluated with JHK(s) photometry alone, hence providing a powerful tool in the analysis of Galactic structure

Anesthesiological management of Caesarean sections. Nationwide survey in Germany

Background. The rate of Caesarean sections in Germany continues to rise. The change in anesthetic technique of choice from general to spinal anesthesia began later than in other countries and at the last survey in 2002 was not widely established. The literature on the anesthetic management of Caesarean sections contains many controversies, for example fluid preload before performing spinal anesthesia and the vasopressor of choice. Other issues have received relatively little attention, such as the level of experience of anesthesiologists working autonomously on the labour ward or the timing of antibiotic prophylaxis. The aim of the current survey was to provide an updated overview of anesthetic management of Caesarean sections in Germany. Material and Methods. A questionnaire was sent out to 709 departments of anesthesiology serving obstetric units in Germany. The questionnaire concerned various aspects of anesthetic management of Caesarean sections. Results. A total of 360 questionnaires (50.8%) were returned of which 346 were complete and could be analyzed, accounting for 330,000 births and 90,000 Caesarean sections per year. The predominant anesthetic method used for Caesarean sections was spinal anesthesia (90.8%) using hyperbaric bupivacaine and in approximately one third of the hospitals surveyed without administering intrathecal opioids. Approximately 12% of the departments surveyed used traumatic Quincke needles. In 86.2% the vasopressor of choice was caffedrine/theodrenaline. Nitrous oxide was used in only 19.2% of departments surveyed when general anesthesia is performed. An antibiotic drug was administered in only 11% of hospitals before cord clamping. In 43.1% no neonatologist was available to treat unexpected critically ill newborns. In 32.1% of departments surveyed residents with less than 2 years experience worked autonomously on the labour ward. Conclusions. Currently the predominant anesthetic technique of choice in Germany is spinal anaesthesia and at a much higher rate than in 2002. In addition 12% of departments use traumatic Quincke needles which are associated with a higher incidence of postpuncture headache. Nitrous oxide is no longer frequently used in Germany. Finally, the administration of an antibiotic before cord clamping has been shown to lead to lower rates of endometritis and postoperative wound infection without detrimental effects on the newborn. This is practiced in only a small minority of departments across Germany