69 research outputs found

    Energy Sustainability of Turkey in the Case of LNG

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    Energy is both vital and strategic element for a nation to sustain its fundamental activities like security, logistics, heating, etc. Countries sustain their energy demands through internal or external sources. In the case of not being able to maintain energy demands from their internal sources, they would need to import their requirements. Whenever they need to buy raw materials, they have to build terminals to process the raw material into the required form. The dependency on the imports may cause the importing country to weaken its advantage in international conflicts, unemployment, and welfare. Therefore, countries aim to mitigate dependence to one country and seek for alternate countries. To keep the energy sustainable, they should not be dependent on a sole supplier country. A state chooses to increase its number of providers; it might cause economic advantages or disadvantages regarding the type of material. Besides, particular type of resources requires specific terminals, facilities, and technology to process the material to be ready to consume. Consequently, decision-makers should employ a holistic approach that should comprehend all of the aspects of the situation. We study the case of importing and building a terminal of Liquefied Natural Gas (LNG) to define criteria in maintaining the energy sustainability and profitability of Turkey

    Design of a Horizontal Penetrometer for Measuring On-the-Go Soil Resistance

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    Soil compaction is one of the main negative factors that limits plant growth and crop yield. Therefore, it is important to determine the soil resistance level and map it for the field to find solutions for the negative effects of the compaction. Nowadays, high powered communication technology and computers help us on this issue within the approach of precision agriculture applications. This study is focused on the design of a penetrometer, which can make instantaneous soil resistance measurements in the soil horizontally and data acquisition software based on the GPS (Global Positioning System). The penetrometer was designed using commercial 3D parametric solid modelling design software. The data acquisition software was developed in Microsoft Visual Basic.NET programming language. After the design of the system, manufacturing and assembly of the system was completed and then a field experiment was carried out. According to the data from GPS and penetration resistance values which are collected in Microsoft SQL Server database, a Kriging method by ArcGIS was used and soil resistance was mapped in the field for a soil depth of 40 cm. During operation, no faults, either in mechanical and software parts, were seen. As a result, soil resistance values of 0.2 MPa and 3 MPa were obtained as minimum and maximum values, respectively. In conclusion, the experimental results showed that the designed system works quite well in the field and the horizontal penetrometer is a practical tool for providing on-line soil resistance measurements. This study contributes to further research for the development of on-line soil resistance measurements and mapping within the precision agriculture applications

    Diagnostic value of diffusion weighted MRI and ADC in differential diagnosis of cavernous hemangioma of the liver.

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    Aims: To investigate the use of diffusion weighted magnetic resonance imaging (DWI) and the apparent diffusion coefficient (ADC) values in the diagnosis of hemangioma. Materials and methods: The study population consisted of 72 patients with liver masses larger than 1 cm (72 focal lesions). DWI examination with a b value of 600 s/mm2 was carried out for all patients. After DWI examination, an ADC map was created and ADC values were measured for 72 liver masses and normal liver tissue (control group). The average ADC values of normal liver tissue and focal liver lesions, the \u201ccut-off\u201d ADC values, and the diagnostic sensitivity and specificity of the ADC map in diagnosing hemangioma, benign and malignant lesions were researched. Results: Of the 72 liver masses, 51 were benign and 21 were malignant. Benign lesions comprised 38 hemangiomas and 13 simple cysts. Malignant lesions comprised 9 hepatocellular carcinomas, and 12 metastases. The highest ADC values were measured for cysts (3.782\ub10.53 710-3 mm2/s) and hemangiomas (2.705\ub10.63 710-3 mm2/s). The average ADC value of hemangiomas was significantly higher than malignant lesions and the normal control group (p<0.001). The average ADC value of cysts were significantly higher when compared to hemangiomas and normal control group (p<0.001). To distinguish hemangiomas from malignant liver lesions, the \u201ccut-off\u201d ADC value of 1.800 710-3 mm2/s had a sensitivity of 97.4% and a specificity of 90.9%. To distinguish hemangioma from normal liver parenchyma the \u201ccut-off\u201d value of 1.858 710-3 mm2/s had a sensitivity of 97.4% and a specificity of 95.7%. To distinguish benign liver lesions from malignant liver lesions the \u201ccut-off\u201d value of 1.800 710-3 mm2/s had a sensitivity of 96.1% and a specificity of 90.0%. Conclusion: DWI and quantitative measurement of ADC values can be used in differential diagnosis of benign and malignant liver lesions and also in the diagnosis and differentiation of hemangiomas. When dynamic examination cannot distinguish cases with vascular metastasis and lesions from hemangioma, DWI and ADC values can be useful in the primary diagnosis and differential diagnosis. The technique does not require contrast material, so it can safely be used in patients with renal failure. Keywords

    The prognostic value of arterial stiffness in systolic heart failure

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    Background: Increased arterial stiffness is an indicator of mortality. This study consists of an 18-month follow-up of the mortality in advanced heart failure patients with increased arterial stiffness.Methods: The study followed up 98 patients with a diagnosis of heart failure in NYHA class III and IV (76 males, 22 females and mean age of 60 ± 12 years) with a left ventricular ejection fraction ≤ 35% as determined by the Simpson method. Augmentation index (Aix) and pulse wave propagation velocity (PWV) parameters were used as indicators of arterial stiffness. Aix and PWV values were measured by arteriography.Results: 36 patients died. Both Aix and PWV were powerful determinants of mortality, independent of other prognostic variables (p = 0.013, OR: 0.805; p = 0.025, OR: 0.853). A cutoff value for Aix of –14.33 gave 91.2%, 80.3% sensitivity and specificity. A cutoff value for PWVof 11.06 gave 82.4%, 65.4% sensitivity and specificity mortality was predicted. Left ventricular ejection fraction (p = 0.008, OR: 0.859) and B-type natriuretic peptide (p = 0.01, OR: 0.833) was the other independent determinant of mortality. A significant difference was found inboth Aix and PWV between the compensated measurements and decompensated heart failure measurements made in 70 patients (p = 0.035, p = 0.048).Conclusions: Measurement of arterial stiffness is a convenient, inexpensive and reliable method for predicting mortality in patients with advanced heart failure

    Cybersecurity Acquisition Framework Based on Risk Management: Economics Perspective

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    Acquisition Research Program Sponsored Report SeriesSponsored Acquisition Research & Technical ReportsCyber attacks continuously target organizations, however, the mitigation actions taken for defense are not sufficiently effective. Ability to compute the cost of attacks is crucial to assess the effectiveness of countermeasure investments. In this study, we developed a framework to have a well-informed decision-making process in cybersecurity acquisition by evaluating the business impact caused by the operability losses of assets. We tested the developed framework using various attack and mitigation scenarios. The findings suggest that using a simulation approach to calculate the business impact of cyber attacks provides the ability to support decision-making process.Approved for public release; distribution is unlimited.Approved for public release; distribution is unlimited

    The effect of activated protein C on experimental acute necrotizing pancreatitis

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    INTRODUCTION: Acute pancreatitis is a local inflammatory process that leads to a systemic inflammatory response in the majority of cases. Bacterial contamination has been estimated to occur in 30–40% of patients with necrotizing pancreatitis. Development of pancreatic necrosis depends mainly on the degree of inflammation and on the microvascular circulation of the pancreatic tissue. Activated protein C (APC) is known to inhibit coagulation and inflammation, and to promote fibrinolysis in patients with severe sepsis. We investigated the effects of APC on histopathology, bacterial translocation, and systemic inflammation in experimental acute necrotizing pancreatitis. MATERIALS AND METHOD: Forty-five male Sprague-Dawley rats were studied. Rats were randomly allocated to three groups. Acute pancreatitis was induced in group II (positive control; n = 15) and group III (treatment; n = 15) rats by retrograde injection of taurocholate into the common biliopancreatic duct. Group I rats (sham; n = 15) received an injection of normal saline into the common biliopancreatic duct to mimic a pressure effect. Group III rats were treated with intravenous APC 6 hours after induction of pancreatitis. Pancreatic tissue and blood samples were obtained from all animals for histopathological examination and assessment of amylase, tumor necrosis factor-α, and IL-6 levels in serum. Bacterial translocation to pancreas and mesenteric lymph nodes was measured. RESULTS: Acute pancreatitis developed in all groups apart from group I (sham), as indicated by microscopic parenchymal necrosis, fat necrosis and abundant turbid peritoneal fluid. Histopathological pancreatitis scores in the APC-treated group were lower than in positive controls (10.31 ± 0.47 versus 14.00 ± 0.52; P < 0.001). Bacterial translocation to mesenteric lymph nodes and to pancreas in the APC-treated group was significantly decreased compared with controls (P < 0.02 and P < 0.007, respectively). Serum amylase, tumor necrosis factor--α, and IL-6 levels were also significantly decreased in comparison with positive controls (P < 0.001, P < 0.04 and P < 0.001, respectively). CONCLUSION: APC improved the severity of pancreatic tissue histology, superinfection rates and serum markers of inflammation during the course of acute necrotizing pancreatitis

    Can pretreatment hepatic artery perfusion scintigraphy in patients with liver malignancies predict the treatment response of the selective internal radiation therapy with 90Y resin microspheres?

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    PURPOSEWe aimed to evaluate whether the perfusion pattern from pretreatment hepatic artery perfusion scintigraphy (HAPS) in patients with liver malignancies can predict response to selective internal radiation therapy (SIRT).METHODSThis retrospective study analyzed 152 consecutive patients treated with yttrium-90 (90Y) resin microspheres between April 2015 and July 2017. HAPS using single-photon emission computed tomography/computed tomography (SPECT/CT) with 99mtechnetium macroaggregated albumin (99mTc-MAA) was performed before SIRT. Investigators visually classified perfusion patterns of tumors as heterogeneous or diffuse in HAPS. Between diffuse and heterogeneous pattern group, positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) were performed in third and sixth month after SIRT, and tumor response assessed and compared by using RECIST 1.1 or mRECIST. Overall survival (OS) and progression-free survival (PFS) were also compared with Kaplan-Meier/log-rank analyses.RESULTSOf 216 SIRT procedures, 172 were classified as heterogeneous and 44 as diffuse. Diffuse 99mTc- MAA uptake was associated with longer median OS than heterogeneous (22.2 vs. 14.4 months, respectively; P = .047). Subsegmental infusion was associated with longer OS than either lobar or segmental infusion (P = .090). Mean estimated OS was longer in patients with hepatocellular carcinoma (HCC) (34.2 months) than with colorectal carcinoma (CRC) (16.4 months) (P = .044). Patients with both diffuse and heterogeneous patterns were able to show complete response after SIRT. No statistically significant differences were observed between perfusion patterns and PFS or response rates to SIRT.CONCLUSIONAlthough tumor perfusion patterns from preplanning HAPS analyses are useful for estimating tumor uptake of 90Y, they may not reliably predict hepatic treatment response, as patients with different perfusion patterns can show clinical response to SIRT

    Clinical usefulness of epicardial adipose tissue in patients with high-intermediate pre-test probability for coronary artery disease

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    Background: Epicardial adipose tissue (EAT) is thought to be associated with the extension and severity of coronary artery disease (CAD), and echocardiographic measurement of EAT thickness is considered to be a possible cardiovascular risk indica­tor. The European Society of Cardiology Task Force recommends further non-invasive testing in patients with an intermediate pre-test probability (PTP) for the diagnosis of CAD. Aim: We sought to evaluate the clinical usefulness of performing EAT measurements in patients with a high-intermediate PTP. Methods: Patients referred to an outpatient clinic with stable chest pain symptoms, with PTP for CAD between 66% and 85%, were included in the study. Echocardiographic measurement of the EAT was identified as the echo-free space between the outer wall of the myocardium and the visceral layer of the pericardium. Single-photon emission computed tomography (SPECT) was performed in all patients. The diagnosis of CAD was based on the presence of reversible perfusion defects on SPECT. Results: A total of 126 patients (76 men, 60.3%) with a mean age of 65.3 ± 9.1 years were recruited. The EAT thickness was 7.3 ± 0.7 mm in patients with positive SPECT and 6.2 ± 0.6 mm in patients with negative SPECT (p &lt; 0.001). Multivariable analysis revealed higher rates of positive SPECT in patients with higher EAT (odds ratio [OR] 9.80; 95% confidence interval [CI] 3.72–25.79; p &lt; 0.001), and receiver operating characteristic curve analysis showed that the greatest specificity was obtained when the cut-off value of EAT thickness was 6.75 mm (sensitivity 76%; specificity 74%). Conclusions: In patients with high-intermediate PTP, EAT is a useful measurement that may assist in risk stratification
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