253 research outputs found

    Properties of gypsum particleboard with added mineral dolomite

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    Red pine (Pinus brutia) wood particles and dolomite mineral were used in varying proportions to form mineral-added gypsum particleboards. Mechanical, physical, and chemical properties of the boards were tested. The increasing  mineral content was found to improve the water absorption properties but the increased amount of  gypsum  in the mixture negatively affected the thickness swelling and water absorption properties. The usage of dolomite mineral in the board composition increased the internal bond properties and higher than the standard of 0,28 MPa. However, all types of boards had modulus of elastic, modulus of rupture and thermal conductivity results values below the standards.  Moreover, the thermal conductivity values decreased in all board types because of the reduction of the mineral dolomite. Thermal gravimetric analysis, Fourier transform infrared spectrometry tests were applied to examine the thermal and flame retardancy properties of inorganic materials, wood-gypsum composites, which are used at different rates for synergistic effect. The gypsum and dolomite amount affected the thermal variation, whereas the increment in the weight of the wood particles also increased the thermal degradation. It was determined that stresses at 850-980 cm-1 reveal Ca-O and Mg-O, reveal at 881cm-1 C-OH, weak vibration at 1619 cm-1 and a strong bond structure in the 1445-950-882 cm-1 bands. These bands express the characteristic presence of the CaO and MgO belonging to dolomite. The study demonstrated the feasibility of producing mineral-based gypsum board products using wood chips

    An early indicator index of tornadic storms for Euro-Mediterranean region

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    Tornadoes are the most violent and destructive of all the severe weather phenomena that localized convective storms produce. There is a requirement in operational meteorology increasing nowadays that an indicator index which allows to reduce the uncertainty of severe convective storms and tornadoes in the scope of climate change adaptation strategies. The main intention is not to replace or substitute mesoscale modeling approaches, or composite indexes, but to warn operationally to draw attention to the Eastern Mediterranean and Türkiye in particular a few days in advance. The development of some indicators using atmospheric variables can undertake a crucial role by enabling such numerical models to be run only at certain time intervals, thus enduring lower computational costs. In this study, Eastern Mediterranean oscillation index (EMEDOi) has been developed in order to be able to detect the presence of ULLs (upper-level low) and frontogenesis approach is employed for selected tornadic storm events in Türkiye. EMEDOi has 7 different its variations (members) which these members have been developed to detect differences depending on the entry directions of cyclones and storms influencing Türkiye from the west of the country. In line with the GDAS data analysis, values of geopotential height are derived for the requirement of EMEDOi in a limited area. A few of the results from the study are as in the following: 86% of the trained tornado events revealed that the EMEDO-Oper index was in negative phase at the time a tornado was reported, regardless of whether the events featured a supercell mesoscale convective storm or a frontal movement. The hourly period until the local minimum is obtained can be described and characterized as the process by which the EMEDO-Oper index value decreases continuously. The time required to reach the local minimum varies based on the tornado occurrence. Based on the tornadic storm scenario in the test cluster in 2022 and the train cluster, this timeframe is predicted to be roughly 33.2 h on average. In western Türkiye, there is a 79% chance of a tornado occurring between six and forty-two hours after the EMEDO-Oper index reaches its local minimum. In particular, the projected chance for this period is 63% between 12 and 30 h after the local minimum is obtained. Besides, the majority of the tornado incidents with EMEDO-Oper values below − 0.75 were evaluated. After an EMEDO-Oper index value falls below that threshold, it is likely to forecast the risk period of a tornado in Türkiye with a probability of 79% and the local minimum point must be identified

    A rare lesıon of breast: Hydatıd cyst

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    Hydatid cyst (HC) is a lesion most commonly seen in the liver but can occur in many parts of the body. Breast involvement with HC  is extremely rare. It can be isolated or accompanied by other organ involvements. In this report, we present a 46-year-old female with  isolated HC located in the right breast. In the ultrasonography and MR images of the patient, the lesion was compatible with the HC,  and homogenous dens lesion was shown on mammography. Diagnosis of HC was confirmed pathological. With this study, it was aimed to emphasize the radiological findings of isolated breast HC

    A Study on Composite Panels Prepared from Mixture of Mineral Adducts with Calabrian Pine Tree (Pinus brutia) Residues

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    The heat transfer coefficient values of 0.250 W/mK and l: 0.261 W/mK were found for Type 1 boards (bark based experimental boards of XBI and YBV)and l: 0.321 W/mK and l: 0.311 W/mK were found for Type 2 boards (cone based experimental boards of XCV and YCII), respectively. But all these are lower than standard value of 0.065 W/mK. However, visual evaluation show that all samples have low flame spreading properties which did not reach the threshold limit of 150 mm under a single flame combustion test. All Type 1 boards show lower mass loss (w, %) than control sample (B0: 11.97%), regardless of mineral additive type and proportions. The lowest mass loss of 6.36% was obtained with sample of YBIV. It is noticeable that olivine-cone (YC) and olivine-bark (YB) based panels usually show lower mass loss than dolomite-cone and dolomite-bark based panels at similar experimental conditions. The surface burning tests clearly indicate that the both mineral additions have lowering effects on burning feature of boards. This is probably olivine and dolomite could be absorbing heat and release water. Hence the burning area might become colder during evaporation of water with increasing charring and improve insulation of materials. The heat insulation levels of boards have found to be closely related with mineral content. But olivine seems to more effective for improving insulation properties for Type 1 boards. It is also found that both type panels (Type 1 and 2) which prepared from various proportions of dolomite and olivine as additives (10-50%) were show higher resistance against thermal degradation than control panels which prepared only (100%) from lignocellulosic material (cone and bark)

    Reducing the Complexity of Normal Basis Multiplication

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    In this paper we introduce a new transformation method and a multiplication algorithm for multiplying the elements of the field GF(2k)(2^k) expressed in a normal basis. The number of XOR gates for the proposed multiplication algorithm is fewer than that of the optimal normal basis multiplication, not taking into account the cost of forward and backward transformations. The algorithm is more suitable for applications in which tens or hundreds of field multiplications are performed before needing to transform the results back

    Sustainable solutions for the construction sector: integration of secondary raw materials in the production cycle of concrete

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    The construction industry is one of the largest consumers of raw materials and energy and one of the highest contributor to green-houses gases emissions. In order to become more sustainable it needs to reduce the use of both raw materials and energy, thus lim-iting its environmental impact. Developing novel technologies to integrate secondary raw materials (i.e. lightweight recycled aggre-gates and alkali activated “cementless” binders - geopolymers) in the production cycle of concrete is an all-inclusive solution to im-prove both sustainability and cost-efficiency of construction industry. SUS-CON “SUStainable, Innovative and Energy-Efficiency CONcrete, based on the integration of all-waste materials” is an European project (duration 2012-2015), which aim was the inte-gration of secondary raw materials in the production cycle of concrete, thus resulting in innovative, sustainable and cost-effective building solutions. This paper presents the main outcomes related to the successful scaling-up of SUS-CON concrete solutions in traditional production plants. Two European industrial concrete producers have been involved, to design and produce both pre-cast components (blocks and panels) and ready-mixed concrete. Recycled polyurethane foams and mixed plastics were used as aggre-gates, PFA (Pulverized Fuel Ash, a by-product of coal fuelled power plants) and GGBS (Ground Granulated Blast furnace Slag, a by-product of iron and steel industries) as binders. Eventually, the installation of SUS-CON concrete solutions on real buildings has been demonstrated, with the construction of three mock-ups located in Europe (Spain, Turkey and Romania

    Effects of Proton Pump Inhibitors and H2 Receptor Antagonists on the Ileum Motility

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    Objectives. To investigate the effects of proton pump inhibitors (PPIs) and H2 receptor antagonists on ileum motility in rats with peritonitis and compare changes with control group rats. Methods. Peritonitis was induced by cecal ligation and puncture in 8 rats. Another of 8 rats underwent a sham operation and were accepted as controls. Twenty-four hours later after the operation, the rats were killed, and their ileum smooth muscle was excised and placed in circular muscle direction in a 10 mL organ bath. Changes in amplitude and frequency of contractions were analyzed before and after PPIs and H2 receptor blockers. Results. PPI agents decreased the motility in a dose-dependent manner in ileum in both control and intraabdominal sepsis groups. While famotidine had no significant effect on ileum motility, ranitidine and nizatidine enhanced motility in ileum in both control and intraabdominal sepsis groups. This excitatory effect of H2 receptor antagonists and inhibitor effects of PPIs were significantly high in control group when compared to the peritonitis group. The inhibitor effect of pantoprazole on ileum motility was significantly higher than the other two PPI agents. Conclusions. It was concluded that H2 receptor antagonists may be more effective than PPIs for recovering the bowel motility in the intraabdominal sepsis situation

    Relationship between psychosocial status, diabetes mellitus, and left ventricular systolic function in patients with stable multivessel coronary artery disease

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    Background: Negative emotional conditions contribute to the development of coronary artery disease (CAD). Depression and anxiety are prognostic factors in patients with CAD. The aim of our study was to investigate the association between emotional conditions and left ventricular (LV) systolic functions in CAD. Methods: 168 patients (102 men, 66 women, mean age 66.3 &#177; 9.9 years) with stable angina and multivessel disease (MVD) were included in the study. According to the LV ejection fraction (LVEF) in echocardiography, patients were divided into two groups, the preserved group (LVEF > 50%), and the impaired group (LVEF < 50%). The preserved group consisted of 94 patients and the impaired group consisted of 74 patients. Emotional status was evaluated using the Hamilton Depression (HAM-D), Hamilton Anxiety (HAM-A), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) scores. Results: The prevalence of diabetes mellitus (DM) was significantly higher in the impaired group than in the preserved group (29.8% vs 56.8%, p < 0.01). The HAM-D, HAM-A, BAI and BDI scores were higher in the impaired group compared to the preserved group (HAM-D: 12.1 &#177; 3.3 vs 14.5 &#177; 2.3, p = 0.03; HAM-A: 12.7 &#177; 3.4 vs 14.3 &#177; 2.2, p = 0.01; BAI: 18.6 &#177; &#177; 6.4 vs 22.1 &#177; 6.6, p = 0.01 and BDI: 13.9 &#177; 2.5 vs 17.2 &#177; 2.0, p = 0.002, respectively). In multivariate analysis, BDI scores (odds ratio [OR]: 2.197, < 95% confidence interval [CI] 1.101&#8211;4.387; p = 0.026), HAM-A scores (OR: 1.912, < 95% Cl 1.092&#8211;2.974; p = 0.041) and DM (OR: 2.610, < 95% Cl 1.313&#8211;5.183; p = 0.006) were important risk factors for LV dysfunction in stable patients with MVD. Conclusions: This study demonstrated that emotional status and DM are factors associated with impaired LV systolic function in patients with stable CAD

    Symptomatic simple renal cyst managed by laparoscopic unroofing in a child

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    Simple renal cysts (SRC) in children are uncommon, usually asymptomatic, and discovered incidentally during investigation for other urinary or abdominal symptoms. The management of SRC in children depends on the symptoms and imaging. Patients can be followed by ultrasonography or other imaging or may be decided an intervention. The available procedures for the treatment of symptomatic cysts are percutaneous aspiration with or without sclerotherapy and open or laparoscopic approaches of the lesions. Only a few small series have been published SRC in children, and is not sufficient data available regarding laparoscopic approach. In this case report, we present a case of symptomatic SRC who underwent laparoscopic unroofing
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