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1.
Materials (Basel) ; 13(24)2020 Dec 10.
Article in English | MEDLINE | ID: mdl-33321852

ABSTRACT

Sewage sludge is a high-volume and low-cost waste commonly generated worldwide, so its utilization is a vital issue. The application of this waste in the manufacturing of lightweight aggregates was investigated. The process was performed using intensive mixers with volumes of 5 and 30 L, as well as the industrial 500 L mixer. Then, granulates were sintered in a tube furnace. The influence of composition and mixer size on the particle size, microstructure, mechanical performance, and stability of lightweight aggregates in different environments was analyzed. The best results were obtained for a 500 L mixer, enhancing the industrial potential of the presented process. Increasing the share of sewage sludge in the composition of aggregates enhanced their porosity and reduced the specific weight, which caused a drop in compressive strength. Nevertheless, for all analyzed materials, the mechanical performance was superior compared to many commercial products. Therefore, sewage sludge can be efficiently applied as a raw material for the manufacturing of lightweight aggregates. The presented results confirm that a proper adjustment of composition allows easy the tailoring of aggregates' performance and cost.

2.
Materials (Basel) ; 10(6)2017 Jun 21.
Article in English | MEDLINE | ID: mdl-28773039

ABSTRACT

Aluminium-based hybrid composites are a new class of advanced materials with the potential of satisfying the demands in engineering applications. This paper describes the effects of carbon addition on the formation and properties of AMC with SiC nanoparticles reinforcement. The composites were produced via mechanical alloying followed by hot pressing. Three forms of carbon, graphite (GR), multiwalled carbon nanotubes (CNTs), and, for the first time, glassy carbon (GC), were used for the hybrid composites manufacturing and compared with tribological properties of Al-SiC composite without carbon addition. GC and CNTs enhanced formation of Al-SiC composite particles and resulted in a homogeneous distribution of reinforcing particles. On the other hand, GR addition altered mechanochemical alloying and did not lead to a proper distribution of nanoparticulate SiC reinforcement. Hot pressing technique led to the reaction between Al and carbon as well as SiC particles and caused the formation of Al4C3 and γ-Al2O3. The subsistence of carbon particles in the composites altered the predominant wear mechanisms since the wear reduction and the stabilization of the friction coefficient were observed. GC with simultaneous γ-Al2O3 formation in the hybrid Al-SiC(n)-C composites turned out to be the most effective additive in terms of their tribological behaviour.

3.
Pol J Pathol ; 67(4): 398-403, 2016.
Article in English | MEDLINE | ID: mdl-28547969

ABSTRACT

The aim of the study was to assess the relationship between the apparent diffusion coefficient in diffusion-weighted magnetic (DWM) resonance imaging (MRI) and selected morphological parameters of the breast lesions. Diffusion-weighted imaging data and the pathology reports of 160 women treated surgically between January 2011 and March 2015 were analyzed. When classified, 107 invasive carcinomas, 13 pre-invasive carcinomas and 40 benign lesions were identified. The mean apparent diffusion coefficient was significantly lower for invasive carcinomas than benign lesions of the breast (0.87 ±0.02 vs. 1.58 ±0.04; p < 0.001). What is more there was an inverse correlation between value of apparent diffusion coefficient in diffusion-weighted magnetic resonance imaging and the grade of breast carcinomas (p = 0.04).


Subject(s)
Breast Neoplasms/diagnostic imaging , Diffusion Magnetic Resonance Imaging/methods , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Middle Aged , Young Adult
4.
Contemp Oncol (Pozn) ; 17(1): 88-93, 2013.
Article in English | MEDLINE | ID: mdl-23788969

ABSTRACT

AIM OF THE STUDY: Radical nephrectomy in the treatment of renal cell carcinoma (RCC) remains the gold standard, but nephron-sparing surgery (NSS) is still increasing in importance. The main goal of this study was to compare the diagnostic accuracy of ultrasound and multi-detector computed tomography in RCC staging and its influence on deciding about further patient treatment. MATERIAL AND METHODS: 87 patients (age range 27-90 years; median 61.5) underwent ultrasound (US) scan and contrast-enhanced computed tomography (CE-CT) of the abdomen and pelvis. 28 patients were qualified for NSS. The remaining group of patients underwent nephrectomy. RESULTS: NSS was performed more frequently among patients with lesions in the lower pole of the kidney and there was no infiltration to the calyx and renal pelvis. Radical nephrectomy (RN) was pursued in cases with lesions in the central or upper pole. Lesion diameter in patients qualified for NSS was smaller than in patients qualified for radical nephrectomy. CONCLUSIONS: Determining the relationship between tumour and adjacent structures is not a simple matter. According to our study, 50% of CT results differ from histopathology assessment. Tumour diameter determined in CT examination is larger than in ultrasound and histopathological measurements while US scanning tends to underestimate tumour size in relation to histopathological assessment.

5.
J Radiol Case Rep ; 4(5): 19-26, 2010.
Article in English | MEDLINE | ID: mdl-22470730

ABSTRACT

The main cause of mortality among patients with breast cancer is the metastatic spread of the primary tumour. The urinary bladder is considered as an unusual site for breast cancer metastasis. A patient has presented with right breast tumour and qualified for surgical treatment. After removal of the mass, an intra-operative and final pathology evaluation indicated breast invasive lobular carcinoma. Adjuvant chemotherapy was given. Years later, an increase of serum CA15-3 tumour marker level was noted and physical examination revealed a lump at the mastectomy scar. A follow-up abdominal ultrasound scan demonstrated thickening of the urinary bladder wall segment, confirmed later by CT scan. A transurethral resection of bladder was performed, reaffirming a neoplastic mass, with histological assessment revealing invasive breast carcinoma. Palliative chemotherapy was given and another follow-up ultrasound scans were unremarkable. The patient is alive today.

6.
Europace ; 12(2): 230-9, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19919967

ABSTRACT

AIMS: Syncope is a common problem. Demographic and clinical characteristics of patients admitted to different types of centres may vary, physician's adherence to the guidelines has been examined only in a few studies, and the requirements for implantable loop recorders (ILR) have not been well defined. The aim of this study was to (i) compare demographic and clinical characteristics of patients with syncope diagnosed and treated in tertiary electrophysiology cardiac centres and those attending syncope units or general hospitals, (ii) assess how physicians adhere to the published guidelines, and (iii) calculate the requirement for ILR insertion. METHODS AND RESULTS: In total, 669 consecutive patients with syncope, admitted to 18 electrophysiological cardiac tertiary centres over a mean of 3 months (range 1-10 months), entered a special Internet database called the PL-US (Polish patients with Unexplained Syncope) registry. Detailed demographic and clinical characteristics of the patients, including the results of all diagnostic tests performed, were analysed. Adherence to the guidelines was assessed, based on the published recommendations. The ILR implantation was indicated when (i) all other tests were inconclusive (unexplained syncope) and (ii) syncope associated with injury or presence of organic heart disease or past medical history and ECG suggesting arrhythmic syncope. Syncope of cardiac/arrhythmic origin was the most frequent diagnosis (53%), followed by reflex syncope (33%). Adherence to the guidelines was less than satisfactory-measurement of blood pressure in an upright position, carotid sinus massage, exercise testing, and electrophysiological study were underused, whereas prolonged ECG monitoring and neurological consultations were overused. Unexplained syncope had 58 (9%) patients, and 42 (72%) of them had indication for ILR which accounts for 6% of the whole study population. The calculated need for ILR was 222 implants/million inhabitants/year. CONCLUSION: Patients with syncope admitted to the tertiary electrophysiology cardiac centres are a highly selected group of patients with syncope and differ in their characteristics as well as underlying diseases to those managed at general hospitals, outpatient clinics, or special syncope units. In Poland, the adherence to the published guidelines is far from satisfactory. At least 6% of all consecutive patients with syncope are candidates for ILR insertion.


Subject(s)
Registries , Syncope/diagnosis , Syncope/epidemiology , Adult , Aged , Blood Pressure/physiology , Cardiac Electrophysiology , Electrocardiography , Female , Guideline Adherence , Hospitals, General , Humans , Male , Middle Aged , Pacemaker, Artificial , Poland/epidemiology , Prospective Studies , Retrospective Studies , Syncope/physiopathology
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