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Experimental Analyses on Cellular Polymers for Geotechnical Applications
No full textCellular polymers represent an important category within the area of the polymeric materials. Although these materials are experiencing a growing importance from both an industrial and an economic point of view, there is not such a big and detailed corresponding scientific literature. Except for the researches directly supported by the manufacturing companies, mainly interested, there are only few scientific and engineering studies about this argument. This article is aimed to the geotechnical characterisation of the rigid polyurethane foam and the extruded polystyrene foam and their physical- mechanical properties. The mechanical behaviour is investigated through oedometric and triaxial tests, performed in either PUR and XPS samples at different densities. As a result, the influence of the density on the relationship stress-strain for the materials is obtained. Practical methods and procedures about how to adapt the geotechnical tests on such materials, different from the soil, are also illustrated. At the end of the analyses, a first attempt of interpretation is given, so that an analytical model for the geotechnical description of cellular polymers can be developed
La termografia in medicina veterinaria "something new about something old": il suo valore diagnostico nel benessere animale
Full text linkThermography is the infrared imaging (or thermal imaging) obtained with an infrared camera. Based on these thermal images it is possibile to perform accurate temperature measurements, to detect even small temperature differences. Scientific applications of infrared thermography are numerous and located in many different areas.
In medicine, the temperature of the body is a complex phenomenon. The body produces heat that must be dispersed into the environment. The skin functions as the interface between heat production and the environment. This dynamic body has adapted to balance the internal and external conditions, in response to physiological needs of the body. Infrared are widely accepted as accurate and reliable tool to perform medical examinations and diagnostic tests.
Many veterinarians already use infrared thermography as a noninvasive method, reliable and fast, to identify hot spots. This technique provides in fact, in real time, a visual map of gradients in temperature of the skin. Because heat is one of the main signals of approaching of inflammation or injury, it is possibile to use infrared camera to detect and diagnose these problems in advance. This technology also allows to easily locate
damaged nerves and muscles. Among the most common applications: axis deviation, diseases of joints, fractures, tendinopathy and many other inflammatory conditions. In
addition to the wide use in the horse sports, is growing strongly the use of infrared materials and in other fields of veterinary medicine, as its use in farms of small and large ruminants, wild animals and into zoo, as a tool for diagnosis of diseases or evaluation of alterations of animal welfare.
Trial 1: Infrared thermography, allowing you to perform evaluations of temperature away from animals and without contact, can be very important in determining their acute stress. The purpose of this study is, therefore, assess the potential of infrared thermography as a technique to detect stress in the horses in order to obtain a noninvasive method of diagnostic and complementary to other diagnostic techniques. The experimental test is to subject various horses to acute stress and to examine certain physiological parameters (blood corticotropin and cortisol, changes in rectal temperature and heart rate) related to changes in temperature, detected by infrared thermography to eye level and the trigone lip. The first report of stress was induced by banding of the eyes of animals (proof of banding), then another test was conducted in which the stressful event was the administration of food so that the horses were able to view it without reaching and smell (proof of frustration).
Our study also provided as a comparison of the response to acute stress in two groups of animals, one of which was placed in enriched environment, the other served as control.
In this experiment participated in 9 horses (aged between 5 and 20 years, belonging to different races) For statistical analysis, given the relatively small number of subjects who have been
part of the experimental evidence, has chosen to use non-parametric statistical tests.
The Wilcoxon test was used for comparison between baseline values and those before the proof and subsequently statistical analysis within the same groups of "enriched" and "control", while the Spearman's rank test was used for the correlation between them.
Baseline analysis of results, in general, we can claim to have observed that the surveys carried out by using the camera, do not significantly influence the parameters considered in animals. There are not major differences between the baseline and the
pre-test, this may indicate that our manual and our presence does not have varied far the physiological conditions of the horses.
In the course of each stress test, however, we have noticed that the infrared camera detects temperature changes, increasing or decreasing, and therefore we have always noticed a difference in temperature between the initial and final values of the tests, both level of eye and lip trigone.
Finally, considering our data between enriched and control group, we can see that even in this case, there is a difference that depends on the type of stress test implementation.
Descriptive analysis of results obtained in enriched and control groups, as has been previously analyzed each group individually, we noted that the proof bandage influence
the temperature of the eye, increasing it, while the trigone is variable. The test of frustration, however, decreases the temperature at eye and attrigone lip.
Trial 2: A proper operation of the milking is essential both for the welfare of the buffalo and for an optimize productivity, maintaining a healthy breast. Rising the vaccum level, while allowing more rapid extraction of milk, the other affects the
integrity of the breast tissue. The increase of the vaccum increases the rate of flow of milk by lowering the time of issuance, but may also be a cause of occurrence of diseases borne apparatus in different species from breast milk. The mechanical action exerted by the compound during the milking vacuum, and the weight of the sheath, induces changes in the tissues of the nipple that may alter the resistance to the entry of
pathogenic bacteria causing infections.
The objective of this study was to evaluate the influence of different levels of high and low vacuum on temperature changes of the nipple in Buffalo, before, during and after the milking process, by infrared thermography.
Within the herd were considered two groups of 14 buffaloes, which were milked at 42kPa and after three weeks of adaptation to progressively lower levels of vacuum were milked at 36kPa, using the same parameters of pulsation.
Thermographic images of the back of the udder and teats were captured before milking, during milking, immediately after milking and up to 5 minutes after milking.
The camera was a practical method for detecting changes at surface temperature of the nipple and analyzing the results obtained using the two tests of milking, we highlighted the important data.
At first observation of the data reveals that the low vacuum influence greater than the high elevation of the nipple thermal vacuum. Another very interesting observation is related to the time of milking: in fact are very similar and therefore the gap found between the temperatures taken after milking, is not due to the time of milking, but probably on the level of vacuum applied.
All these tests have shown a higher sensitivity of the middle and tip teat from the base, applying equally high or low vacuum. This implies a greater influence of the nipple at both anatomical and thermal.
Trial 3: Subacute rumen acidosis (SARA) represent one of the most important metabolic disorders in intensive dairy farms that affects rumen fermentations, animal welfare, productivity and profitability. The determination of ruminal pH is a key factor
for the diagnosis of SARA. Different methods are available for the collection of rumen fluid for pH analysis. According several researcher rumenocentesis may be useful for the collection of rumen fluid for pH determination. A group of at least 12 cows (early or middle lactation) is defined as having SARA when more than 30% of them show a ruminal pH lower than 5.5.
The purpose of this study was to verify the applicability of thermography as a tool as an aid to diagnosis of this disorder fermentative. Also, apply the thermographic evaluation
of point of needle insertion from rumenocentesis in order to further confirm the absence of negative implications of this technique on the health and animal welfare.
The results of this study may show how infrared thermography can be of great importance as a tool as an aid to diagnosing subacute rumen acidosis because the alterations of ruminal fermentations leads to a change in temperature of the rumen
and/or surface circulation in relation to the mechanisms of heat loss.
Moreover, since some authors still consider rumenocentesis as an invasive technique and various professionals deem too difficult to use in routine clinical investigations, this study has again demostrated that no animal has shown particular problems during this diagnostic procedure, and not have been identified local or systemic reactions following the ruminocentesisLa termografia è la produzione di immagini a infrarossi (o immagini termiche) ottenute con una telecamera a infrarossi, detta termocamera. Sulla base di tali immagini termiche
si possono eseguire accurate misurazioni della temperatura, per individuare differenze di temperatura anche minime.
Le applicazioni scientifiche della termografia a infrarossi sono numerose e localizzate nei campi più disparati.
In campo medico la temperatura del corpo è un fenomeno complesso. L'organismo produce calore che si deve disperdere nell'ambiente. La cute funziona da interfaccia tra la produzione di calore e l'ambiente. Questo organo dinamico si adegua costantemente per bilanciare le condizioni interne ed esterne, rispondendo alle esigenze fisiologiche del corpo. Gli infrarossi sono ampiamente accettati come strumento accurato e affidabile per effettuare esami medici e diagnostici.
Numerosi medici veterinari utlizzano già la termografia a infrarossi come metodo non invasivo, affidabile e rapido, per individuare punti caldi. Questa tecnica fornisce infatti, in tempo reale, una mappa visiva dei gradienti della temperatura della cute. Poichè il calore è uno dei segnali principali dell'approssimarsi di infiammazioni o infortuni, si possono usare gli infrarossi per individuare e diagnosticare con largo anticipo tali problemi. Questa tecnologia consente anche di individuare facilmente nervi e muscoli lesionati. Tra le applicazioni più comuni: deviazioni assiali, patologie articolari, fratture,
tendinopatie e molti altri stati infiammatori. Oltre al largo impiego nel cavallo sportivo, sta crescendo fortemente l'utilizzo degli infrarossi anche in altri campi e materie della medicina veterinaria, come il suo utilizzo negli allevamenti di piccoli e grandi ruminanti, selvatici e zoo, come strumento di diagnosi di patologie e valutazione di alterazioni di benessere animale.
Lavoro 1: La termografia ad infrarossi, permettendo di eseguire valutazioni di temperatura lontano dagli animali e senza contatto, può essere molto importante nella determinazione di un loro stress acuto. Lo scopo di questo studio è, perciò, valutare le potenzialità della termografia ad infrarossi come tecnica per individuare lo stress nel cavallo sportivo, al fine di ottenere un metodo non invasivo e complementare ad altre
tecniche diagnostiche. La prova sperimentale consiste nel sottoporre diversi soggetti ad uno stress acuto ed esaminare se alcuni parametri fisiologici (corticotropina ematica, cortisolo ematico, variazioni della temperatura rettale e frequenza cardiaca) ed altri di tipo comportamentale potessero essere in relazione alle variazioni della temperatura, rilevate con l'ausilio della termografia ad infrarossi, a livello dell'occhio e del trigono
labiale. La prima situazione di stress è stata indotta mediante il bendaggio degli occhi degli animali (prova di bendaggio); successivamente è stata svolta un'altra prova nella quale l'evento stressante è stato la somministrazione di cibo in modo tale che i cavalli riuscissero a vederlo ed annusarlo senza raggiungerlo (prova di frustrazione).
Il nostro studio prevedeva, inoltre, il confronto della reazione ad uno stress acuto di due gruppi di animali; uno di questi è stato posto in ambiente arricchito, l'altro fungeva da controllo. L'arricchimento ambientale da noi messo in pratica è stato di tipo alimentare.
A questo esperimento hanno partecipato 9 cavalli (di età compresa tra 5 e 20 anni, appartenenti a varie razze). Per l'analisi statistica, dato il numero relativamente ridotto dei soggetti che hanno fatto parte della prova sperimentale, si è scelto di usare test statistici di tipo non parametrico.
Il test di Wilcoxon è stato utilizzato per il confronto tra i valori basali e quelli antecedenti ogni prova stressogena e successivamente per l'analisi statistica all'interno degli stessi gruppi di "arricchito" e di "controllo"; mentre il test per ranghi di Spearman è stato utilizzato per le correlazione tra gli stessi. Nell'analisi dei risultati basali, in generale, possiamo affermare di aver osservato che le rilevazioni effettuate mediante l'uso della termocamera, non influenzano in maniera significativa i parametri considerati negli animali. Abbiamo potuto osservare che, infatti, nonostante le correlazioni e le differenze significative riportate per alcuni parametri in alcuni gruppi, non vi sono differenze rilevanti tra i valori basali e quelli pre prova; questo può indicare che le nostre manualità e la nostra presenza non hanno variato di molto le condizioni fisiologiche dei cavalli.
Nel corso di ogni singola prova di stress, invece, abbiamo potuto notare che la termocamera ad infrarossi rileva variazioni della temperatura, in aumento o in diminuzione, ed abbiamo perciò sempre rilevato una differenza della temperatura tra i valori iniziali e finali delle prova, sia a livello di occhio sia di trigono labiale.
Infine, Esaminando i nostri dati tra gruppo arricchiti e controllo, possiamo notare che, anche in questo caso, vi è una differenza che dipende dal tipo di prova di stress messa in atto. Dall'analisi descrittiva dei risultati ottenuti nei gruppi arricchiti e di controllo, così come constatato analizzando in precedenza ogni gruppo singolarmente, abbiamo notato che la prova di bendaggio influenza la temperatura dell'occhio, aumentandola, mentre quella del trigono risulta variabile; la prova di frustrazione, invece, diminuisce la temperatura sia a livello oculare sia di trigono labiale.
Lavoro 2: Un corretto funzionamento dell'impianto di mungitura è essenziale sia per il benessere della bufala che per ottimizzare la produttività e mantenere una mammella sana. L'innalzamento del vuoto di lavoro se da un lato consente un'estrazione più rapida del latte, dall'altro condiziona l'integrità dei tessuti mammari. L'aumento del vuoto operativo accresce la velocità di deflusso del latte diminuendo i tempi di emissione, ma può anche essere causa dell'insorgenza di patologie a carico dell'apparato mammario nelle diverse specie da latte. L'azione meccanica esercitata durante la mungitura dall'effetto combinato del vuoto, delle guaine e del peso del gruppo, induce dei cambiamenti nei tessuti del capezzolo che ne possono alterare la resistenza all'ingresso dei batteri patogeni causa di infezioni mastitiche.
L'obiettivo di questa ricerca è stato quello di valutare l'influenza dei diversi livelli di alto e basso vuoto sui cambiamenti di temperatura del capezzolo nella bufala, prima, durante e dopo il processo di mungitura, attraverso la termografia ad infrarossi.
All'interno della mandria sono stati considerati due gruppi di 14 bufale, le quali venivano munte a 42kPa e dopo tre settimane di adattamento a livelli di vuoto progressivamente più bassi, erano munte a 36kPa, usando gli stessi parametri di pulsazione.
Le immagini termografiche dell'area posteriore della mammella e dei capezzoli erano catturate prima della mungitura, durante la mungitura, immediatamente dopo la mungitura e fino a 5 minuti dopo la mungitura.
La termocamera è risultata un metodo pratico per la rilevazione di alterazioni della temperatura superficiale del capezzolo ed analizzando i risultati ottenuti eseguendo le due prove di mungitura, abbiamo evidenziato dei dati importanti.
Ad una prima osservazione dei dati si nota che il basso vuoto influenza maggiormente l'innalzamento termico del capezzolo rispetto all'alto vuoto. Un'altra osservazione piuttosto interessante è relativa ai tempi di mungitura: infatti sono molto simili e dunque il gap riscontrato tra le temperature prese dopo la mungitura, non è dovuto ai tempi di mungitura, ma probabilmente dal livello di vuoto applicato.
Tutte queste analisi hanno dimostrato una superiore sensibilità del middle teat e del tip teat rispetto alla base teat, applicando indistintamente alto o basso vuoto. Ciò implica una maggiore influenza del capezzolo sia a livello anatomico, che termico.
Lavoro 3: L'acidosi ruminale subacuta (SARA dall'Anglosassone: subacute ruminal acidosis) rappresenta una delle principali problematiche nell'allevamento della bovina da latte, in grado di provocare notevoli ripercussioni economiche, sia dirette che indirette. Dalle ricerche effettuate in questi ultimi anni, si può affermare che la tecnica più idonea e sicura per il prelievo del liquido ruminale al fine di una diagnosi presuntiva di SARA è la ruminocentesi: in un'azienda si effettua la ruminocentesi in un gruppo di 12 bovine nelle prime fasi di lattazione e si emette diagnosi di SARA quando almeno il 30% delle bovine in esame presenta un pH ruminale inferiore a 5.5.
Scopo del presente lavoro è stato quello di verificare l'applicabilità della termografia ad infrarosso quale mezzo d'ausilio per la diagnosi di tale disturbo fermentativo; inoltre è
stata valutata l'applicabilità della termografia nel punto di inserzione dell'ago da ruminocentesi al fine di valutare (o escludere) eventuali implicazioni negative di tale tecnica sullo stato di salute e benessere dell'animale.
Dai risultati di tale studio si può indicare come la termografia ad infrarosso possa essere di grande importanza quale mezzo d'ausilio per la diagnosi di SARA, per il fatto che l'alterazione delle fermentazioni ruminali conduce ad una variazione di temperatura del rumine e/o di circolo superficiale in relazione ai meccanismi di termo dispersione.
Inoltre, a conferma di quanto ampiamente indicato in bibliografia i risultati del presente studio confermano che la ruminocentesi rappresenta uno strumento utile e prezioso di diagnostica in medicina bovina e che tale manualità non provoca alcun danno dal punto di vista della salute e del benessere della bovina da latt
Experimental analyses on cellular polymers in different forms for geotechnical applications
No full textCellular polymers represent an important category among the polymeric materials. Nowadays they experience large applications in different areas (packaging, building, sport, road safety). There is already a widespread geotechnical use of these materials, e.g. for settlements reduction or soil strengthening, especially for existing structures. However, a need of a deeper mechanical properties study is required. Oedometric and triaxial laboratory tests have already been carried out on polyurethane samples obtained from ready-to-be-used slabs (RTBU samples). However, because of a will of polyurethane foam injection inside the soil, an ad-hocprepared foam needs to be prepared and its mechanical properties to be investigated. This paper is therefore aimed to analyse the geotechnical behaviour of the ad-hoc-prepared foam (by testing AHP samples), studying the influence of several factors on the applicability, and comparing the results with the failure tests conducted on RTBU samples
The role of plants in the prevention of soil-slip: the G-SLIP model and its application on territorial scale through G-XSLIP platform
No full textThis paper discusses the role of plants in the prevention of shallow landslides induced by rain (soil slips); these phenomena, related to “hydrogeological instability”, are among the most feared because their evolutionary processes can cause huge damages and losses of human lives when interacting with anthropized areas and infrastructures. The paper first highlights how the plants interact with the soil; then introduces the G-SLIP (Green - Shallow Landslides Instability Prediction) model, i.e. the simplified physically-based SLIP model, modified to predict soil slips at punctual and large scale taking into account the vegetation effects. G-SLIP model is thus applied to a case study of the Parma Apennines (Northern Italy) by using the G-XSLIP platform. In this area, during the intense events of rain between the 4th and 5th of April 2013, numerous landslides occurred, provoking huge damages to structures and infrastructures, and consequent economic losses. The stability analyses carried out with G-XSLIP demonstrate that the presence of vegetation in the study area led to a significant reduction in the triggering of shallow landslides. Finally, an attempt of soil slip mitigation through naturalistic techniques (planting of specific vegetation) is presented
An experimental and numerical model for wave propagation studies in sandy soils
No full textIn recent years, an ever increasing interest in reducing seismic risk is developing. Innovative solutions related to soil interventions are going to be studied. This paper shows the preliminary steps of the construction of an experimental apparatus, whose aim is the study of wave propagation in little scale through a sandy soil, in axisymmetric conditions. Single-Input-Multiple-Output impact hammer tests are performed in order to study the experimental response in both time and frequency domain. Alongside the experimental system, a 3D – FEM model able to reproduce the experimental tests is therefore proposed, for its calibration and in order to determine the problem unknowns with back analysis procedures. Results from the numerical modal and dynamics analyses show a great correspondence with the experimental data, confirming the goodness of the system
The role of plants in the prevention of soil-slip: the G-SLIP model and its application on territorial scale through G-XSLIP platform
No full textThis paper discusses the role of plants in the prevention of shallow landslides induced by rain (soil slips); these phenomena, related to “hydrogeological instability”, are among the most feared because their evolutionary processes can cause huge damages and losses of human lives when interacting with anthropized areas and infrastructures. The paper first highlights how the plants interact with the soil; then introduces the G-SLIP (Green - Shallow Landslides Instability Prediction) model, i.e. the simplified physically-based SLIP model, modified to predict soil slips at punctual and large scale taking into account the vegetation effects. G-SLIP model is thus applied to a case study of the Parma Apennines (Northern Italy) by using the G-XSLIP platform. In this area, during the intense events of rain between the 4th and 5th of April 2013, numerous landslides occurred, provoking huge damages to structures and infrastructures, and consequent economic losses. The stability analyses carried out with G-XSLIP demonstrate that the presence of vegetation in the study area led to a significant reduction in the triggering of shallow landslides. Finally, an attempt of soil slip mitigation through naturalistic techniques (planting of specific vegetation) is presented
AI-driven predictions of the dynamic properties of fine-grained soils in South Italy based on laboratory testing
Full text linkA SLIP-based post-failure model to predict the propagation of soil slips and their interaction with infrastructures
No full textRainfall-induced shallow landslides (also called soil slips) are natural phenomena which can be triggered suddenly anywhere, even in areas with no previous landslide history, causing unexpected damage when interacting with the built environment. The damage could be sometimes extensive, as occurred to the "Madonna del Monte"overpass located in the Italian highway A6 (Torino-Savona), which collapsed in November 2019 because of the interference of a large soil slip. This paper shows a new methodology to analyze the propagation of soil slips and their interference with infrastructures, with specific attention to roads. Failure is detected through the physically-based model SLIP, while the post-failure evolution is investigated through a simplified model, based on SLIP results and the geomorphology of the area. The proposed approach is applied to an area in Enna (Sicily, southern Italy) where on 2nd February 2014 shallow landslides were triggered after intensive rainfall, interfering with the Provincial Road SP2 and the State Road SS117bis. Volume and average speed of the debris flow are estimated by the model and could be used in further analyses of impact with the surrounding infrastructures, showing the potential of the methodology
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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