Water saturation induced changer in the indirect (Brazilian) tensile strength and the failure mode of some igneous rock materials

The present study concentrates on water induced strength reduction and variation of the failure mode in indirect (Brazilian) tension tests of several igneous rock materials under three moisture cases of oven-dry, air-dry and fully saturated states. In this respect, two andesite and three tuff materials which contain no visible flaws were subjected to indirect tensile strength tests using the Brazilian disc method. Once the tension tests were carried out, photographs of the broken samples were taken to investigate the changes in the failure mode. As a result, it was found that tensile strengths of the samples were highly reduced with the presence of the water and the natural humidity. Additionally, it has been deduced that the failure mode of the samples mainly shifts to central fracturing with the presence of natural moisture and saturation. Although the central crack is the ideal type for the theory of Brazilian tensile strength determination, indefinite contact properties like contact angle and frictions are some notable issues to make only considering failure shapes for the validity of the test results misleading

River Flow Estimation from Upstream Flow Records Using Support Vector Machines

A novel architecture for flood routing model has been proposed and its efficiency is validated on several problems by employing support vector machines. The architecture is designed by including the inputs and observed and calculated outflows from the previous time step output. Whole observed data have been used for determining the model parameters in the heuristic methods given in the literature, which constitutes the major disadvantage of the existing approaches. Moreover, using the whole data for training may lead to overtraining problem that causes overfitting of estimations and data. Therefore, in this study, 60-90% of the data are randomly selected for training and then the remaining data are used for validation. In order to take the effects of the measurement errors into consideration, the data are corrupted by some additive noise. The results show that the proposed architecture improves the model performance under noisy and missing data conditions and that support vector machines can be powerful alternative in flood routing modeling

Efficacy of preheated chelating agents on calcium ion removal from instrumented root canals

The heating of chelating agents such as EDTA increases dentin wettability by decreasing surface tension. However, the calcium ion release effect of preheated chelating agents in instrumented root canals has not yet been mentioned. In this s

Emotion Analysis using Different Stimuli with EEG Signals in Emotional Space

Automatic detection for human-machine interfaces of the emotional states of the people is one of the difficult tasks. EEG signals that are very difficult to control by the person are also used in emotion recognition tasks. In this study, emotion analysis and classification study were conducted by using EEG signals for different types of stimuli. The combination of the audio and video information has been shown to be more effective about the classification of positive/negative (high/low) emotion by using wavelet transform from EEG signals, and true positive rate of 81.6% was obtained in valence dimension. Information of audio was found to be more effective than the information of video at classification that is made in arousal dimension, and true positive rate of 73.7% was obtained when both stimuli of audio and audio+video are used. Four class classification performance has also been examined in the space of valence-arousal

Paget’s Disease of the Breast in a Patient with Amyopathic Dermatomyositis

Amyopathic dermatomyositis (AD) can be a part of paraneoplastic syndrome of an underlying malignancy. Paget’s disease is a rare form of breast cancer. We present a very rare case of Paget’s disease associated with AD. Paget’s disease has been diagnosed in a patient with AD who is under surveillance of dermatology department. The patient has undergone central lumpectomy with removal of the nipple-areola complex and sentinel lymph node biopsy. Surgical margins after lumpectomy and sentinel node biopsy were negative. The whole breast irradiation was performed after surgery. The patient receives medical treatment for AD of which lesions regressed in 1 year during the follow-up period. This is a very rare case of Paget’s disease diagnosed in a patient with AD. Female patients with dermatomyositis have been absolutely recommended to undergo screening for breast and gynaecological malignancies. AD may be an early finding of primary or recurrent malignancy of the breast

A Case of Lichen Sclerosus et Atrophicus Accompanying Bullous Morphea

Bullous morphea is a rare form of morphea characterized with bullae on or around atrophic morphea plaques. Whereas lichen sclerosus et atrophicus (LSA) is a disease the etiology of which is not fully known, and which is characterized with sclerosis. Coexistence of morphea and LSA has been identified in some cases. Some authors believe that these two diseases are different manifestations which are on the same spectrum. The 70-year-old patient stated herein, presented to us for 6 months with annular, atrophic plaques, ivory color in the middle, surrounded by living erythema, on the front and back of the trunk. Occasionally bulla formation on the plaques on the trunk lateral was identified. Fibrotic and atrophic plaques of ligneous hardness were present on the front side of tibia of both legs. In the histopathologic examination, the lesions were found concordant with bullous morphea and LSA. With colchicine 1.5 mg/day, pentoxifylline 1,200 mg/day, topical calcipotriol ointment and clobetasol propionate cream, the erythema in the patient's lesions faded and softening in the fibrotic plaques was observed. Concomitance of bullous morphea and LSA is a rarely seen, interesting coexistence which suggests a common, as yet unknown, underlying pathogenesis

Cutting Characteristics of a Ductile Rock

A rock sample was obtained from an underground lignite mine for the investigation of the cutting characteristics of a ductile rock where the heading is achieved with a roadheader. The rock sample (metasiltstone) was classified according to a pertinent brittleness classification by means of its compressive strength to tensile strength ratio. Two types of drag picks are used for the execution of the experimental campaign on core and block samples of the metasiltstone. The cutting force, the specific energy and the breakout angle variables were investigated. The cutting force-distance histories of cutting trials were compared with the present literature. It was seen that even an extremely ductile rock sample exhibited the characteristics of brittle cutting regime

Drag pick cutting tests: A comparison between experimental and theoretical results

This paper aims at reporting the results of a number of drag pick cutting tests on selected igneous rock samples to compare the experimentally determined maximum cutting force (FC′) values with theoretically estimated ones. First, a review on theoretical rock cutting models proposed for both chisel and conical picks was presented in detail. Experimental study consists of both chisel and conical pick cutting tests in unrelieved (single-pick) cutting mode with varying cutting depths. FC′ values were determined from experimental results, and theoretical models were utilized to compute FC′ for all cutting conditions. Computed and experimentally determined FC′ data were then compared for a referenced cutting depth. It is shown that the theoretical models might overestimate or underestimate FC ′ and cannot give reliable results. Finally, explanations for these mismatches were presented. Keywords: Rock cutting mechanics, Rock cutting tests, Vertical rock cutting rig (VRCR), Cutting force, Rock cutting theorie

Pulmonary hypertension in the elderly

Pulmonary hypertension is defined as 25mmHg or higher mean pulmonary arterial pressure measured by right heart catheterization. Miscellaneous diseases may cause PH. Among these are pulmonary arterial hypertension (PAH), left heart disease, pulmonary disorders and hypoemia, and chronic thromboembolic disease. Pulmonary hypertension (PH) is seen frequently in the elderly. Although diseases resulting in systolic and diastolic dysfunction with accompanying pulmonary venous hypertension (PVH) account for a large percentage of PH in this population, PH associated with other respiratory diseases, such as chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), and sleep apnea can also be seen. Idiopathic pulmonary arterial hypertension (IPAH) is, although rarely, seen and requires careful exclusion in older patients. PAH associated with connective tissue disease is the most encountered form of PAH. Since the treatment to all these disease is different, differential diagnosis has the utmost importance

A case difficult to diagnose in adults: High sinus venous atrial septal defect

Sinus venous atrial septal defect (SVD) is highly difficult to diagnose because of its location. Below, we report a case of SVD which is misdiagnosed as pulmonary hypertension and anomalous pulmonary venous return. A 57-year-old female patient was referred to congenital disease outpatient clinic of a tertiary center. She was admitted to the hospital with complaints of fatigue and exercise dyspnea which had started a year ago. She had transthoracic echocardiography (TTE) examination done in another hospital which showed dilated right heart chambers and pulmonary hypertension. She underwent transesophageal echocardiography (TEE) examination with the suspicion of atrial septal defect (ASD), but no defect was seen. As her symptoms persisted, we repeated the TTE and TEE examination in our center. TEE revealed 0.6 cm ASD on the upper side of the interatrial septum. All four pulmonary veins were draining into the left atrium. Right heart catheterization (RHC) confirmed the diagnosis. A left-to-right shunt was detected and localized by a significant step-up in blood oxygen saturation found between mid and upper segments of the right atrium. According to our TEE and RHC results, we planned the surgical closure of the defect. Sinus venous ASD is deficiency of the superior portion of atrial septum adjacent to superior vena cava. Diagnosis of SVD is often more difficult than other forms of ASD and may require special imaging such as TEE, magnetic resonance imaging, or computed tomographic scanning. In conclusion, cardiologists must be aware about the possibility of SVD patients who have unexplained exertional dyspnea and fatigue, dilated right atrium and ventricle, pulmonary hypertension, paradoxical embolism, or atrial arrhythmias in their respective populations