40 research outputs found
Valutazione del tempo di maturazione dei massetti nella determinazione del livello di calpestio dei solai
No full textLa norma UNI EN ISO 140-8, per la determinazione della riduzione di rumore di calpestio trasmesso da rivestimenti di pavimentazioni in laboratorio, prescrive un tempo di stagionatura di tre settimane prima della misura nel caso di massetti galleggianti in calcestruzzo. Tale raccomandazione deriva dalla necessità di sollecitare la struttura solo dopo il completamento delle reazioni chimiche di indurimento del legante cementizio e ed eliminata la maggior parte dell’umidità dell’impasto. Il tempo di stagionatura dei massetti condiziona fortemente le tempistiche dell’attività di laboratorio, per cui è stata condotta una verifica su alcuni allestimenti, analizzando i livelli di rumore di calpestio normalizzato per circa un mese per ciascun campione, con lo scopo di valutare se una eventuale riduzione dei tempi di attesa porti ad un risultato compreso entro l’errore di misura
Experimental Analysis of the Different Behavior of Materials for Impact Sound Insulation in Buildings in Relation to the Kind of Base Floor: a Comparison Among Laboratory Measurements on a Concrete Slab and on a Hollow Brick and Concrete Bare Floor
No full textMaterials for impact noise insulation are tested according to the standards ISO 140-8 and ISO 717-2 with laboratory measurements of impact noise level attenuation on a concrete slab. However, the behavior of such materials can be different when applied on non-homogeneous floors. In this work have been reported some data of impact noise level attenuation measured in laboratory on a concrete slab and on a hollow brick and concrete bare floor, built with the same junction typology and with no flanking transmission, to evaluate the difference of the same materials applied to different structures
Influence of the Sample Preparation for Dynamic Stiffness Tests on the Calculation of Impact Noise Level Attenuation
No full textThe performances of materials used for impact noise insulation can be estimated when dynamic stiffness is known, together with other mechanical properties measured through small samples tests. However, the calculation of impact noise level attenuation from dynamic stiffness data, according to the standards, can be influenced by the testing methodologies adopted, in particular the presence or absence of the gypsum layer between the sample and the steel plate. In this work a comparison between impact noise level attenuation calculated from dynamic stiffness data of different materials and measured in laboratory according to ISO 140-8 is done, in order to check the precision of the theoretical calculation and the influence of different test methodologies
Cytokeratin positivity in bone marrow cells as predictor of onset of bone metastases in patients with advanced breast cancer.
No full textObjective: Despite screening programs, advances in therapeutic approaches and understanding the molecular bases of cancer biology, breast cancer (BC) remains the first cause of cancer death in women aged over 50 years. Bone is one of the most common sites of metastasis in BC patients, and the presence of disseminated tumor cells in bone marrow (BM) seems to have a strong independent prognostic value. The aim of this study was to investigate whether the immunocytochemical detection
of disseminated tumor cells in BM can be considered as predictor of onset of bone metastases in patients with advancer BC.
Material and Methods: A group of 21 surgically treated women (median age 54, range 47–68 years) with advanced (stage II-III) BC and no evidence of distant metastases at first diagnosis were followed-up for at least 24 months. All patients underwent whole bone scan or 18 F-FDG-PET for inclusion in the study, together with a baseline BM aspirate from the posterior iliac crest. The cells were stained with a monoclonal antibody against cytokeratin (CK). A according to the ISHAGE guidelines, CK+cells were scored as tumor cells. Six out of 21 (28.6 %) patients (cases) developed bone metastases, while 15 (controls) had no evidence of distant metastases.
Results: Risk ratio (RR), 95 % confidence interval (CI), and the relative p-value (p) using Fisher exact test between cases and controls were calculated. The following parameters have been considered: age 5 AN+)(RR=2.5, 95 %CI 0.91-6.87, p=0.11), and
CK+(RR=3.21, 95 %CI 1.25-7.78, p=0.02).
Conclusion: The presence of CK+cells in the BM specimen should be considered a strong predictor (p5 AN+and ER- are weak predictors
Analisi comparativa delle prestazioni acustiche in laboratorio di pareti rivestite
No full textI recenti sviluppi di mercato nel settore dell’edilizia hanno determinato una crescen-te necessità, per le aziende produttrici di materiali per l’isolamento acustico, di offrire nuove soluzioni dedicate agli interventi di risanamento di edifici esistenti. La possibilità di incrementare le prestazioni acustiche di edifici, che non soddisfano appieno i requisiti acustici passivi minimi definiti dal D.P.C.M. 5/12/1997, è importante anche alla luce dei criteri di classificazione definiti nella norma tecnica UNI 11367, la principale novità normativa di settore.
In questo lavoro viene presentata un’analisi sperimentale condotta in laboratorio per lo sviluppo e l’ottimizzazione di prodotti per l’isolamento acustico del rumore aereo in applicazioni di rivestimento di pareti in muratura. I materiali testati sono in gran parte provenienti da riciclo, in abbinamento a strati di finitura in cartongesso
Analisi comparativa delle prestazioni acustiche di pareti leggere
No full textLe pareti leggere in cartongesso sono generalmente dotate di buone prestazioni fonoisolanti, soprattutto se l’intercapedine viene riempita con specifici materiali assorbenti. Rispetto agli allestimenti in laboratorio, l’installazione delle pareti leggere in opera può essere accompagnata da rilevanti perdite di fonoisolamento dovute principalmente alle trasmissioni laterali, alla presenza degli impianti elettrici e sanitari, oppure ad errori di posa. In questo lavoro sono stati raccolti dati di potere fonoisolante provenienti da misure in laboratorio, riguardanti oltre cinquanta pareti in cartongesso contenenti materiali riciclati, in particolare pannelli in gomma pressata e fibre di poliestere, per valutarne le prestazioni globali e studiare una possibile interazione tra i diversi componenti. Inoltre, sono state condotte alcune verifiche sulle perdite di potere fonoisolante in laboratorio, a causa dell’inserimento degli impianti elettrici
Ottimizzazione delle metodologie di qualificazione di camere riverberanti per la valutazione dell'isolamento acustico di elementi edilizi
No full textL’appendice C della norma UNI EN ISO 140-3 riporta la procedura di qualificazione dei laboratori di prova con soppressione della trasmissione laterale, che permette di determinare, in particolare, il numero raccomandato di posizioni di sorgente sonora. Il metodo è basato sulla valutazione delle differenze tra i livelli sonori misurati negli ambienti di prova, a partire da un ampio numero di posizioni di sorgente. La norma non fornisce tuttavia un criterio univoco per la collocazione dei punti di misura nei volumi disponibili, in quanto essa dipende dalla geometria specifica delle camere. Inoltre, non conoscendo a priori le posizioni microfoniche da utilizzare, nemmeno la valutazione delle differenze dei livelli sonori può essere effettuata secondo un criterio univoco. All’interno di questo lavoro è stata riportata la procedura di qualificazione adottata per la messa a punto di un laboratorio di nuova costruzione presso la ditta Isolgomma S.r.l., di Albettone (VI), realizzato con la collaborazione del Dipartimento di Fisica Tecnica dell’Università degli Studi di Padova
Acoustics behaviour of CLT structure: Transmission loss, impact noise insulation and flanking transmission evaluations
No full textDesign and construction of CLT structures is now known throughout the world thanks to its known properties, its high thermal resistance to low energy consumption and its low environmental impact. For these reasons, the studies and research on the acoustic performance analysis of these wood panels have also been very successful in recent years. This document aims to present the continuation of the investigative work carried out by Isolgomma on CLT structures, completing the study on the acoustic behaviour of floors with wall and flanking transmission analysis. Therefore, the results of the laboratory acoustic characterization of the CLT walls are presented with the application of different techniques for improving the possible performances, according to the standards of the ISO 10140 series. Furthermore, the considerations related to the study carried out on the joints of the structures are reported. CLT on a large-scale test configuration, according to the standards of the ISO 10848 series. Through this analysis it was possible to obtain the vibration reduction indices both of the bare CLT structure and of the isolated structure through the insertion of a specific anti-vibration rubber mat
Bone alkaline phosphatase and osteocalcin as markers of osteoporosis in postmenopausal women with breast cancer and bone metastases.
No full textObjective(s): Breast cancer (BC) is a heterogeneous tumor that occurs predominantly in elderly women. The overall estimated number of new BCs in the USA in 2011 was 232,000, accounting for about one-third of cases of cancer in women. It continues to be one of the most common causes of cancer death. BC frequently metastasizes to the skeleton, and it is estimated that 85% of individuals with advanced disease harbor bone metastases (BM). Bone alkaline phosphatase (BAP) and osteocalcin are widely used to check the response to therapy in patients with progressive bone disease. The aim of this study was to evaluate whether a correlation exists between bone remodeling serum markers BAP and osteocalcin, and BMD in women with BC and BMs.
Material & Methods: Data from a group of 18 postmenopausal women (median age 65 years, range 54-74 years) who have undergone surgery for invasive BC and successively developed BMs were retrospectively analyzed. Lumbar spine (L2-L4) BMD using DXA, and serum BAP and osteocalcin were measured in all patients. According to the WHO criteria, 13 patents (subgroup A) had mild or moderate osteoporosis (T-score -2.5 through -4 SD), while 5 (subgroup B) had severe osteoporosis (T-score of<-4 SD) Results: Age (62.2±5.6 vs. 68.8±4.2 years, p=0.061), baseline BAP (27.8±7.3 vs. 34.8±7.4 U/L, p=0.088) and osteocalcin (22.8±7.4 vs. 31.4±8.7 ng/mL, p=0.081) did
not differ significantly (subgroup A vs. B). There was no relationship between age, BMD, BAP and osteocalcin serum levels in subgroup B, while in the subgroup A, only a week correlation (R=0.72, p=0.018) between BAP and
osteocalcin was observed, and no relationship (p=NS) between BMD, age, and serum markers was found. Conclusion(s): In patients with BMs from advanced BC, the action of local osteolytic factors, such as PTHrP, together
with direct bone resorption by lytic metastasis, may cause a severe bone disease. In postmenopausal women with BC and BMs the effects on bone of age and cancer together likely overlap, and the relationship between age, BMD, and bone remodeling serum markers is not maintained.
References: Lumachi F et al. Anticancer Res 2009;29:1551
