54 research outputs found

    POMIAR STRUMIENIA MIESZANINY GAZ-CIECZ Z WYKORZYSTANIEM KRYZY STANDARDOWEJ I KRYZY SZCZELINOWEJ

    Get PDF
    The differential pressure of gas measurement is very often used in industrial measurements. During the gas flow, liquid condensation often occurs. The result is that when measuring a gas flow, the gas-liquid mixture is essentially measured. Errors in the indications of measuring instruments are starting to appear due to a change in the properties of the continuous phase, which is gas. In addition, the appearance of liquid droplets leads to flow disturbances and pressure pulsations. Therefore, new methods and tools for measuring the flow of gas-liquid mixture are being sought. The work involves the use of slotted orifices for measuring gas-liquid mixtures. An analysis of the influence of the slotted orifice geometry on the measurement of the biphasic mixture stream was carried out. Standard orifice and three slotted orifices of various designs. The experiment included measuring the air flow with a small amount of water dispersed in the form of drops.Pomiar gazu metodą zwężkową jest bardzo często stosowany w pomiarach przemysłowych. Podczas przepływu gazu bardzo często dochodzi do wykroplenia się cieczy. Powoduje to, że mierząc przepływ gazu w zasadzie mierzy się mieszaninę gaz – ciecz. Zaczynają pojawiać się błędy wskazań przyrządów pomiarowych wynikających ze zmiany właściwości fazy ciągłej, którą jest gaz. Dodatkowo pojawienie się kropel cieczy prowadzi do powstawania zaburzeń przepływu i pulsacji ciśnienia. W związku z tym  poszukuje się nowych metod i narzędzi do pomiaru przepływu mieszaniny gaz-ciecz. Praca obejmuje zastosowanie kryz szczelinowych do pomiaru mieszanin gaz-ciecz. Przeprowadzono analizę wpływu geometrii kryzy szczelinowej na pomiar strumienia mieszaniny dwufazowej. Badaniom kryzę standardową oraz trzy kryzy szczelinowe o różnych konstrukcjach. Eksperyment obejmował pomiar przepływu powietrza z niewielką ilością wody rozproszonej w postaci kropel

    Funkcjonalizacja mezoporowatej krzemionki SBA-15 w wyniku szczepienia poliwinyloaminy na powierzchni modyfikowanej grupami epoksydowymi

    Get PDF
    Mesoporous SBA-15 silica was modified by grafting of 3-glycidoxypropyltrimethoxysilane (GPTMS). An influence of GPTMS/SBA-15 mass ratio used during this pre-functionalization step on the real amount of epoxy-silane grafted on the SBA-15 surface was studied by thermogravimetry and elemental analysis. The pre-functionalized SBA-15 was subsequently used to attach polyvinylamine (PVAm) chains by the opening of oxirane rings and the formation of bonds with NH2 groups from PVAm. The yield of this process was determined. Furthermore, SEM (scanning electron microscopy), DRIFT (diffuse reflectance infrared Fourier transform spectroscopy) and XPS (X-ray photoelectron spectroscopy) as well as zeta potential measurements were applied to observe the changes in the chemical composition of SBA-15 surface and morphology of the synthesized materials. Various types of organic functionalities present on the modified SBA-15 were identified and analyzed quantitatively.Powierzchnię mezoporowatej krzemionki SBA-15 zmodyfikowano na drodze szczepienia 3-glicydoksypropylotrimetoksysilanu (GPTMS). Z wykorzystaniem metod analiz elementarnej oraz termograwimetrycznej badano wpływ stosunku masowego GPTMS/SBA-15 zastosowanego we wstępnej modyfikacji na rzeczywistą zawartość wprowadzonych na powierzchnię krzemionki grup epoksydowych. Do powierzchni zmodyfikowanego SBA-15 przyłączono następnie łańcuchy poliwinyloaminy (PVAm) w wyniku reakcji otwierania pierścieni oksiranowych połączonej z utworzeniem wiązań z grupami NH2 pochodzącymi od PVAm. Określono wydajność tego procesu. Badania SEM (skaningowej mikroskopii elektronowej), DRIFT (spektroskopii odbicia rozproszonego w podczerwieni), XPS (spektroskopii fotoelektronów) oraz pomiary potencjału zeta pozwoliły na ocenę zmian składu chemicznego powierzchni SBA-15 oraz morfologii zsyntetyzowanych materiałów. Zidentyfikowano oraz oznaczono ilościowo różne rodzaje grup funkcyjnych obecnych na powierzchni modyfikowanej krzemionki SBA-15

    Carcinomatous meningitis as a clinical presentation of lung adenocarcinoma : case report

    Get PDF
    Nowotworowe zajęcie opon mózgowo-rdzeniowych jest rzadko występującym powikłaniem choroby nowotworowej o niekorzystnym rokowaniu. Największe ryzyko zajęcia opon mózgowo-rdzeniowych odnotowano w przypadku nowotworów układu krwiotwórczego, raka sutka, raka płuca, czerniaka i gruczolakoraków przewodu pokarmowego. Zróżnicowana manifestacja kliniczna nowotworowego zapalenia opon mózgowo-rdzeniowych wynika z równoczesnego i wielopoziomowego zajęcia układu nerwowego, co implikuje wdrożenie szerokiej diagnostyki różnicowej. Rozpoznanie ustala się, opierając się na korelacji obrazu klinicznego z wynikami badań dodatkowych, w szczególności badania analitycznego i cytologicznego płynu mózgowo-rdzeniowego oraz badania rezonansu magnetycznego z kontrastem. W niniejszej publikacji zaprezentowano przypadek 59-letniej pacjentki z nowotworowym zapaleniem opon mózgowo-rdzeniowych, które stanowiło pierwszą manifestację gruczolakoraka płuca.Carcinomatous meningitis is a rare complication of a malignant disease with a fatal outcome. The greatest predilection for neoplastic meningitis was observed in the course of hematological malignancies, breast cancer, lung cancer, melanoma and gastrointestinal adenocarcinomas. The simultaneous and multilevel nervous system involvement results in the diverse clinical manifestation, therefore it requires a wide differential diagnosis. The diagnosis is based on the correlation of the clinical presentation with the results of additional tests, especially the examination of cerebrospinal fluid and magnetic resonance imaging with contrast. We present the case of 59-year old woman with the carcinomatous meningitis as the first manifestation of lung adenocarcinoma

    Investigation on the Low-Temperature Transformations of Poly(furfuryl alcohol) Deposited on MCM-41

    Get PDF
    MCM-41-type mesoporous silica was used as a support for poly(furfuryl alcohol) deposition. This material was produced by precipitation–polycondensation of furfuryl alcohol (FA) in aqueous slurry of the SiO2 support followed by controlled partial carbonization. By tuning the FA/MCM-41 mass ratio in the reaction mixture, various amounts of polymer particles were introduced on the inner and outer surface of the MCM support. The thermal decomposition of the PFA/MCM-41 composites was studied by thermogravimetry (TG) and spectroscopic techniques (DRIFT, XPS), whereas the evolution of textural parameters with increasing polymer content was investigated using low-temperature adsorption of nitrogen. The mechanism of thermal transformations of PFA deposited on the MCM-41 surface was discussed in detail. It was found that heating at a temperature of about 523 K resulted in opening of the furan rings and the formation of γ-diketone moieties, which were found to be the highest effective surface species for the adsorption of polar volatile organic compounds. A further increase in calcination temperature caused a drop in the amounts of surface carbonyls and the appearance of condensed aromatic domains.This work was supported by the Polish Ministry of Science and Higher Education under Grant N N507 553238. Rafał Janus thanks the Foundation for Polish Science MPD Programme cofinanced by the EU European Regional Development Fund for the financial support. The research was carried out with equipment purchased thanks to financial help from the European Regional Development Fund within the framework of the Polish Innovation Economy Operational Program (Contract POIG.02.01.00-12-023/08)

    Proton pump inhibitor (PPI) administration and Clostridioides difficile infection - is this a real clinical problem? A critical review of the literature

    Get PDF
    Background: Proton pump inhibitors (PPIs) are widely used drugs that reduce gastric acid secretion. In recent years, there has been a gradual increase in their use. The safety of prolonged PPI therapy and the potential for cumulative side effects of these drugs raise legitimate concerns. An association between PPI administration and the risk of Clostridioides difficile infection has been suggested. The findings regarding this phenomenon require further unequivocal verification. Material and methods: A review of publications obtained from the PubMed database and published between 2016-2023. Based on the keywords "proton pump inhibitor", "PPI" and "Clostridium", 132 articles were selected. Finally, 6 meta-analyses were included in the analysis. Results: Studies conducted in recent years have shown a statistically significant increase in the risk of C. difficile infection in patients taking PPIs compared to those who avoid this therapy. The aforementioned relationship was observed in both adults and pediatric patients. One study proved that the risk remained high even up to 1 year after the end of treatment. The described relationship is still a matter of debate due to the fact that patients using antacids are usually elderly, have several comorbidities and a higher risk of developing C. difficile infection regardless of PPI use. Conclusions: The relationship between the use of PPIs and the risk of developing C. difficile infection is still controversial, which justifies the need for continued clinical trials to objectively resolve this issue. PPIs exert high efficacy in the treatment of acid-dependent diseases, but due to the many ambiguities surrounding possible side effects, caution in their administration seems warranted, especially for long-term therapy in elderly patients with polypharmacy

    The role of probiotics in the treatment of depressive disorders. A critical review

    Get PDF
    Depressive disorders are a widespread problem in modern medicine. According to current data from the World Health Organisation, an estimated 280 million people worldwide suffer from depression. In recent years, there have been reports of a correlation between the composition of the gut microbiota and the development of depressive disorders and attempts to modify it through the use of psychobiotics. The literature from the PubMed database published between 2018-2023 has been explored. 596 articles were selected based on the keywords "probiotics" and "depression". Six randomized clinical trials were finally included in the analysis. As defined elsewhere, psychobiotics are probiotic bacteria which supplemented in adequate amounts, interact with the gut-brain axis and show beneficial effects on patients' mental health. Results from recent RCTs suggest that daily probiotic supplementation significantly reduces the severity of depression compared to placebo (p<0.05). Additionally, this effect may be enhanced by the combined use of a probiotic with a prebiotic. Furthermore, some researchers indicate that probiotics may lead to significant improvements in cognitive function in patients suffering from depressive disorders. In conclusion, intestinal dysbiosis may be an important factor leading to the development of mental illness. Results of recent studies suggest that specific strains of probiotic bacteria may offer therapeutic benefits in the treatment of the aforementioned disorders. However, further clinical studies are needed to objectively confirm the relationship between gut microbiota composition and the development of depression

    Oral squamous cell carcinoma – do we always need elective neck dissection? evaluation of clinicopathological factors of greatest prognostic significance: a cross-sectional observational study

    Get PDF
    The aim of the study was to find clinical and pathological factors with the greatest prognostic significance in patients with OSCC. The analysis included 125 patients grouped according to the tumor primary site (TPS): the floor of the mouth (FOM), tongue (TC) and retromolar triangle (RMT). Grading (G), tumor size (pT), nodal metastases (NM), local recurrence (LR), nodal recurrence (NR), perineural invasion (PNI), lymphovascular invasion (LVI), extranodal extension (pENE), and nodal yield (NY) were evaluated in each group.ResultsWith regard to TPS, FOM appeared to be the most metastatic. However, the recurrence rate was similar to TC tumors, which were characterized by higher G than those in other locations. When analyzing G, the highest percentage of LR (40.5%) and NM (34.5%) was observed among patients with G2. As G increased, so did the number of pENE G1 – 7.4%; G2 – 31%; G3 – 35.7%; LVI: G1 – 25.9%; G2 – 50%; G3 – 57.1%; PNI: G1 – 29.6%; G2 – 47.6%; G3 – 92.9%; NR G1 – 14.8%; G2 – 32.1%; G3 – 21.4%. Grading did not affect the type of growth and did not directly affect the occurrence of NR. pT and DOI increased the frequency of NM but we did not observe any effect of pT and DOI on LR, PNI, and LVI. NY in the study group did not increase the risk of NR.ConclusionTumor primary sites within the FOM, TC, and pT classification are the factors that increase the risk of NM and LR. However, apart from the primary site predisposing to the occurrence of NM, the histological structure of the tumor turned out to be the most important feature affecting the patient’s prognosis. The number of cases of pENE+, LVI+, PNI+, NM+, and NR+ increased with the increase in G. Although the pT, DOI increased the frequency of NM, we did not observe the effect of the pT and DOI on LR, PNI and LVI. Thus, even in the case of a small tumor of the FOM and TC with at least G2, elective neck dissection should be performed each time
    corecore