The Vibroacoustic Analysis of The Hydrocarbon Processing Plant Piping System Operating at Elevated Temperature.

In this paper it is presented the vibroacoustic analysis of the selected section of the hydrocarbon processing chemical plant piping system operating at elevated temperature and subjected to dynamic load exciting vibration of the structure. The pump suction and discharge piping system is a part of chemical plant for processing hydrocarbon mixture at 270° C. Elevated temperature is one of static loads that influences the boundary conditions of the piping structure thus generating pump nozzle loadings leading to possible pump body deflection. Deflected shape of the pump body results in generation of flow fluctuation, visible and measurable as a pressure pulsation. This kind of fluctutation has been assumed further to be one of the dynamic loading on piping system structure. The dynamic analysis was performed to quantify the loading effect of pressure pulsation excited in the pump discharge nozzles on the structure of pipelines and the connected pump nozzles. The simulation was based on the numerical analysis of the excitation by acoustic waves propagation in subjected piping system. Measured on–site pressure pulsation at pumps nozzles has been identified and assumed to be the source of the acoustic waves. In the simulation elastic features of the piping structure as well as the fluid, and pressure loses in pipes, taken into account. Final result of the acoustic part of the simulation was spectral characteristics of the acoustic shock forces, defined further as harmonic loads for the dynamic structural analysis. To observe an influence of the acoustic excitation on the piping there was performed structural analysis of the piping system and the combined results of static and dynamic loading influence determined. This part of the analysis has been perfomed by means of FEM computer software Bentley AutoPIPE as well as some use of ANSYS FEM program. Important step in this simulation there was the theoretical modal analysis. This analysis allows to predict possible vibroacoustic resonance in the structural system under specific conditions of the coincidence between acoustic excitation and modals. The results of the combined static and dynamic loadings analysis contain the information on the node displacements, internal forces, resulting stresses in the pipe walls and loads on the pump nozzles and piping supports

Neurofibromatosis type 2 (NF 2) or schwannomatosis? – Case report study and diagnostic criteria

Introduction Neurofibromatosis type 2 (NF2) and schwannomatosis are entities that may, due to the similarity of clinical symptoms, cause diagnostic difficulties. Incidence rate of both diseases is similar and estimated between 1:25,000 and 1:40,000. The genes associated with the development of the aforementioned disorders are located on chromosome 22 and lay in proxmity. Schwannomatosis is characterized by an incomplete penetrance and the risk of its transmission to the offspring is significantly lower than in the case of NF 2. Schwannomatosis clinical characteristic is similar to the NF2, however vestibular schwannomas are not present. Therefore the imaging studies evaluated by an experienced radiologist play a key role in the diagnostic process. Case report Forty two-year-old female hospitalized three times because of the tumors of the spinal canal was admitted to the Department of Neurosurgery and Peripheral Nerve Surgery in 2008 because of the cervical pain syndrome with concomitant headache. She was diagnosed with a schwannomatosis, recently distinguished, the third form of neurofibromatosis. MRI imaging revealed craniocervical junction tumor. Suboccipital craniectomy with concomitant C1–C2 laminectomy was done in order to remove the lesion. After the surgery the patient did not present any deficits in neurological examination and was discharged from hospital in good general condition. Conclusions The patient was diagnosed with schwannomatosis, recently established neurofibromatosis entity which may resemble NF2 clinically. In patients after the age of 30, in whom we observe multiple schwannomas without the concomitant hearing impairment, the diagnosis of schwannomatosis is very likely

The time‐cost trade‐off analysis in construction project using computer simulation and interactive procedure

Several criteria must be considered while preparing the schedule of a construction project. The completion time and project cost are analyzed in most cases. Additionally, the risk related to the criteria has to be taken into account as well. Thus, project planning problem can be denned as a multicriteria decision problem under risk. In this paper, a project scheduling problem including time‐cost trade‐offs is analyzed. We assume that various resource allocations can be considered. A new technique based on computer simulation and interactive approach is proposed. In the first step, simulation experiments are performed to evaluate decision alternatives with respect to the criteria. An interactive technique INSDECM is employed for generating the final solution of the problem. The procedure uses stochastic dominance rules for comparing decision alternatives with respect to the criteria. A numerical example is presented to illustrate the applicability of the technique. Santrauka Rengiant statybos projekto įvykdymo grafiką reikia įvertinti keletą kriterijų. Daugeliu atvejų analizuojamas projekto baigimo laikas ir sąmatinė kaina. Taip pat gali būti įvertinama rizika. Taigi projekto planavimo problema gali būti apibūdinama kaip daugiakriterinė sprendimo problema įvertinant riziką. Straipsnyje analizuojama projekto planavimo problema, suderinant projekto įvykdymo laiką ir kainą. Remiamasi prielaida, kad galimi įvairūs išteklių paskirstymai. Pasiūlyta nauja metodologija, pagrįsta kompiuteriniu modeliavimu ir interaktyvaus metodo taikymu. Pirmuoju etapu imitaciniais modeliais įvertinamos sprendimo alternatyvos. Antruoju etapu galutiniam problemos sprendimui taikoma interaktyvi INSDECM metodologija. Šioje procedūroje, siekiant palyginti sprendimo alternatyvas pagal kriterijus, taikomos stochastinės dominavimo taisyklės. Naujos metodologijos taikymą iliustruoja skaitmeninis pavyzdys.  First published online: 21 Oct 2010 Reikšminiai žodžiai: projekto planavimas, daugiakriterinių sprendimų priėmimo automatizavimas, laiko ir kainos suderinamumas, interaktyvi metodologija, modeliavimas

Surface TLR2 and TLR4 Expression on Mature Rat Mast Cells Can Be Affected by Some Bacterial Components and Proinflammatory Cytokines

The aim of our study was to determine whether some bacterial components as well as some proinflammatory cytokines can affect surface mast cell levels. By the use of flow cytometry technique, we documented that freshly isolated mature rat peritoneal mast cells do express surface TLR2 and TLR4 protein, but not CD14 molecules, and respond to stimulation with TLR2 and TLR4 ligands by cysteinyl leukotriene generation. The level of TLR2 protein is modulated by PGN and CCL5 treatment, but not by LPS, LAM, TNF, or IL-6. Surface mast cell TLR4 expression is affected by LPS, LAM, IL-6, and CCL5. Considering that TLR-mediated activation conditions not only engaged these cells in antibacterial defense and development of inflammation but also might influence allergic processes, our observations that surface TLR2 and TLR4 expression can be regulated both bacterial components and proinflammatory cytokines seem to be very intriguing and importance

Effects of Polylactide Copolymer Implants and Platelet-Rich Plasma on Bone Regeneration within a Large Calvarial Defect in Sheep

The aim of this study was to verify whether L-lactide/DL-lactide copolymer 80/20 (PLDLLA) and platelet-rich plasma (PRP) trigger bone formation within critical-sized calvarial defects in adult sheep ( = 6). Two craniectomies, each ca. 3 cm in diameter, were created in each animal. The first craniectomy was protected with an inner polylactide membrane, filled with PRP-polylactide granules, and covered with outer polylactide membrane. The second control craniectomy was left untreated. The animals were euthanized at 6, 7, 17, 19, 33, and 34 weeks after surgery, and the quality and the rate of reossification were assessed histomorphometrically and microtomographically.The study demonstrated that application of implantsmade of PLDLLA 80/20 combined with an osteopromotive substance (e.g., PRP) may promote bone healing in large calvarial defect in sheep. These promising proof-of-concept studies need to be verified in the future on a larger cohort of animals and over a longer period of time in order to draw definitive conclusions

Antiarrhythmic drugs for pharmacological cardioversion of atrial fibrillation and sex differences: Insights from the CANT II Study

Background: Data on sex differences in terms of action of antiarrhythmic agents (AADs) are limited. This study aimed to evaluate the clinical profile of patients with atrial fibrillation (AF), and efficacy and safety of AADs used for pharmacological cardioversion (PCV) of AF.Methods: This research was a sub-analysis of the retrospective multicenter Cardioversion with ANTazoline II (CANT) registry, which comprised 1365 patients with short-duration AF referred for urgent PCV with the use of AAD. Patients were categorized according to and compared in terms of clinical parameters and PCV outcomes. The primary endpoint was return of sinus rhythm within 12 hours after drug infusion, and the composite safety endpoint involved bradycardia <45 bpm, hypotension, syncope, or death.Results: The sex distribution of patients qualified for PCV was even (men, n = 725; 53.1%). Females were older and more symptomatic and had higher CHA2DS2-VASc scores, higher prevalence of tachyarrhythmia, and higher use of chronic anticoagulation. The overall efficacy (71.4% vs. 70.1%; P = 0.59) and safety (5.2% vs. 4.6%; P = 0.60) of PCV was comparable in men and women. Amiodarone (68.3% vs. 65.9%; P = 0.66) and antazoline (77.1% vs. 80.0%; P = 0.19) had similar efficacy in men and women, but propafenone had a lower rate of rhythm conversion in men (64.7% vs. 79.3%; P = 0.046). None of the assessed AADs differed in terms of safety profile in both sexes.Conclusion: Female patients with AF have different clinical profiles but similar efficacy and safety of AADs as compared to male participants. Propafenone has significantly lower efficacy in men, which requires further investigation