76 research outputs found

    Effect of ultra-low temperature on some mechanical properties of painted and film-coated plywood

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    Plywood is used for insulation systems in liquid natural gas cargo ships because of its good thermal properties. However, there are only a few research investigating the mechanical properties of plywood exposed to ultra-low temperatures. This study aims to determine how plywood reacts when exposed to ultra-low temperatures, such as - 196 °C. To achieve this purpose, the present study investigated the bending strength, modulus of elasticity, and tensile-shear strength of painted and film-coated plywood under ultra-low temperatures. The mechanical properties of plywood were discovered to be significantly impacted by the ultra-low temperature as a result of this research.. Moreover, not only the bending strength of the painted and film-coated plywood increased with decreasing temperature, but also the modules of elasticity of the painted and film-coated plywood increased. At decreasing temperature, the tensile shear strength of the painted and film-coated oven-dried plywood increased, but the ensile-shear strength of painted and film-coated air-dried plywood decreased. The tensile shear strength of air-dried plywood was determined to be more sensitive to the temperature change. Therefore, attention should be paid to plywood used in liquefied natural gas cargo ships with high humidity

    Proizvodnja laganih troslojnih iverica iskorištenjem otpadnih autoguma

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    The aim of the study is to investigate the production possibilities of particleboard by using waste tirerubbers with different properties as fillers and find a solution to a serious environmental pollution problem caused by waste tires. For this purpose, waste summer and winter tires were ground, rubber powders were obtained by separating rubber materials from other materials, and particleboards with different properties were produced using this sawdust in different percentages. The oven-dry density, air-dry density, and equilibrium moisture content at (65±5) % RH and (20±2) ºC, thickness swelling (TS, 2 hours and 24 hours), water absorption (WA, 2 hours and 24 hours) characteristics, bending strength, modulus of elasticity, and internal bond strength were determined according to the applicable European standards. The hydrophobic nature of the tire rubber enhanced the water absorption ratios of particleboards. In addition, mechanical performance of groups was affected by tire content, and it was mainly determined that the values decreased dramatically with increasing tire content. It was especially observed that this decrease was more pronounced when subtracting 30 % to 20 % waste tire content. The groups including winter waste tire rubber achieved better performance than summer waste tire groups. The use of waste rubber in boards resulted in a decrease in the equilibrium moisture content and mechanical strength of the samples.Cilj ovog rada bio je istražiti mogućnosti proizvodnje ploča iverica iskorištenjem otpadnih autoguma različitih svojstava kao punila te pronalaženje rješenja za ozbiljno onečišćenje okoliša otpadnim autogumama. Za potrebe eksperimenta samljevene su otpadne ljetne i zimske autogume, a odvajanjem gumenih od negumenih dijelova dobiven je prah gume, koji se u različitim omjerima upotrebljavao za proizvodnju ploča iverica različitih svojstava. Prema europskim standardima određena su ova svojstva ploča iverica: gustoća u apsolutno suhom i prosušenom stanju, relativni sadržaj vode pri (65±5) RH i (20±2) °C, debljinsko bubrenje (TS, nakon 2 sata i 24 sata) i upijanje vode (WA, nakon 2 sata i 24 sata). Zbog hidrofobne prirode praha autoguma povećani su omjeri upijanja vode ploča iverica. Osim toga, udjel dodane količine praha autoguma utjecao je na mehanička svojstva ploča iverica te je utvrđeno da se te vrijednosti drastično smanjuju s povećanjem količine praha autoguma u pločama. Posebno je naglašeno smanjenje mehaničkih svojstava ploča iverica kada udio praha autoguma prijeđe 20 %. Uzorci ploča iverica s prahom od zimskih guma imali su bolja svojstva od uzoraka s prahom od ljetnih guma. Uporaba otpadnih autoguma u proizvedenim ivericama rezultirala je smanjenjem ravnotežnog sadržaja vode i mehaničke čvrstoće uzoraka

    Live Cell Imaging of Bone Marrow Stromal Cells on Nano-pitted and Polished Titanium Surfaces: A Micro-Incubator in vitro Approach

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    Current orthopedic implants are not conducive for optimal integration of the biomaterial with newly-formed tissue (osseointegration) inside a patient’s body. In this study, medical-rade Ti-6Al-4V was used as a substrate due to its biocompatibility and ability to facilitate cellular adhesion and proliferation. Live cell imaging was conducted on bone marrow stromal cells, genetically modified to express the green fluorescent protein (GFP), from the 24-96 hours growth period, with the first 24 hours of growth being held inside a lab-scale incubator. Periodic images were recorded on nanopitted anodized and polished Ti-6Al-4V substrates to study how substratestiffness influences adhesion and proliferation. Collected images were analyzed for mitosis, adhesion, and filopodia-stretchability using ImageJ, an image processing program. Images were enhanced in order to perform cell counts at 24, 48, 72, and 96 hours of growth. Continuous recordings were produced to account for the number of mitosis occurrences and cellular migration on each of the substrates. Based on the conducted experiments, it appears that polished Ti-6Al-4V has a higher cell adherence than “nanopitted” anodized surface and an improved rate of proliferation which may be because the cells once adhered on the nano-pitted surface have less ability to detach in-order to undergo mitosis.https://engagedscholarship.csuohio.edu/u_poster_2014/1004/thumbnail.jp

    An interesting journey of an ingested needle: a case report and review of the literature on extra-abdominal migration of ingested Foreign bodies

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    Swallowed foreign bodies encounter a major problem especially in children, but fortunately they mostly do not cause any related complication and are easily passed with the stool. In this paper, an interesting journey of a needle is presented. A 20-year old female admitted to our emergency service after she had swallowed a sewing machine needle, which is initially observed in the stomach in the plain abdominal radiography. During the follow-up period, the needle traveled through bowels, and surprisingly was observed in the left lung on 10th day of the follow-up. It was removed with a thoracotomy and pneumotomy under the fluoroscopic guidance. The postoperative period was uneventful and the patient was discharged from the hospital on the day 5. We also review the literature on interesting extra-abdominal migrations of swallowing foreign bodies

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Intra-abdominal use of taurolidine or heparin as alternative products to an antiadhesive barrier (Seprafilm (R)) in adhesion prevention: An experimental study on mice

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    PURPOSE: Seprafilm (R) (Genzyme Biosurgery, Cambridge, MA) remains a widely used product in postoperative adhesion prevention. This study was designed to compare the antiadhesive effects of taurolidine, heparin, and Seprafilm (R) in a murine cecal abrasion model. METHODS: Sixty male Balb/c mice underwent a cecal abrasion procedure and were randomized into four groups (n=15 in each). Groups T, H, and S animals intraperitoneally received taurolidine, heparin, and Seprafilm (R), respectively, and Group C animals were reserved as control. Animals were killed on Day 21, and the severity of adhesions was evaluated with a scoring system ranging between 0 to 5. In addition, the localizations of the adhesions were questioned. RESULTS: Five (1 in Group S and 4 in Group H) animals died before they were killed. The deaths were related to intra-abdominal bleeding, and mortality rate was significantly higher in Group H than those in other groups (P < 0.05 for each comparison). The severity of adhesions was significantly less in the study groups than Group C, and in Group H than Groups T and S (P < 0.05 for each comparison). In addition, adhesions located cecum over itself were significantly less in the study groups than the control group, and those between small bowel and cecum were significantly lower in Groups T and S than the control group (P < 0.05 for each comparison). CONCLUSIONS: All products are effective in adhesion prevention. Heparin use provides the best results but may be associated with a higher mortality rate related to intra-abdominal bleeding. Taurolidine may be an alternative product to Seprafilm (R), but further studies are required
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