Диссипация энергии динамического деформирования в дорожных одеждах автомобильных дорог

Compression strength is the most important factor in concrete structures, and there are two methods to evaluate that compressive strength, destructive and non-destructive method. This work presents a study on the deference and comparison between Destructive (compressive strength test) and a Non-Destructive Method (Rebound Hammer and Ultrasonic test) for testing the compressive strength of concrete.The investigations aimed to develop the method of assessment the strength of concrete of both non-destructive tests with greater accuracy. Destructive method, to determine the strength of the in-situ concrete, and also destructive testing (DT), includes methods where the material is broken down in order to determine its mechanical properties. From the obtained results it is observed that the Rebound Hammer readings increased with the compressive strength of concrete. And the Ultrasonic pulse velocity were greatly influenced by the cements and aggregate, extent of moist curing and presence of flaws and voids in concrete, more than their influence on the measured strengths. This demonstrates the limitation of using ultrasonic pulse velocity tests for estimating compressive strength of concrete. Combined use of Ultrasonic pulse velocity (UPV) and Rebound Hammer tests for assessment of concrete strength in structures with greater reliability.

New predictive models to evaluate concrete compressive strength using the SonReb method

Destructive methods are commonly used to evaluate residual stresses in a wide range of engineering components. While seemingly less attractive than non-destructive methods because of the specimen damage they cause, the non-destructive methods are very frequently the preferred choice because of their versatility and reliability. Many different methods and variations of methods have been developed to suit various specimen geometries and measurement objectives. Previously, only specimens with simple geometries could be handled, now the availability of sophisticated computational tools and of high-precision machining and measurement processes have greatly expanded the scope of the destructive methods for residual stress evaluation. This paper reviews several prominent destructive measurement methods, describes recent advances, and indicates some promising directions for future developments.

Contrast-enhanced ultrasound has shown convincing results for monitoring vessel morphology, surrogate markers of vascularization and changes in molecular marker expression in oncological and cardiovascular diseases. Ultrasound contrast agents have the ability to increase the backscattering signal intensity of an ultrasound pulse. An interesting class of ultrasound contrast agents are gas filled microbubbles, which can be synthesized by external bubble encapsulation using sugar matrices or microspheres consisting of lipids or polymers with or without surfactant and by selecting gases with low blood solubility and diffusion coefficient such as perfluorocarbons or sulphur hexafluoride. Ultrasound contrast agents can be classified according to the rigidity of their shell. Soft-shell microbubbles are coated with a thin monolayer of surfactant molecules such as palmitic acid or phospholipids and are very sensitive to pressure changes. Hard-shell microbubbles have a rigid shell made of polymers such as polycyanoacrylate, which dramatically increases their stability. Depending on the acoustic properties of the microbubbles and on the purpose of the examination either destructive or non destructive methods are preferred for their detection. Microbubbles can be detected by destructive and non-destructive methods. Both soft- and hard-shell microbubbles coated with target-specific molecules can also be used for molecular imaging. Using target-specific approaches, the expression of several angiogenic markers such as VEGFR2, alphavbeta3 Integrins, ICAM, and E-selectin has been investigated in neoplastic and vascular diseases. This article summarizes the synthesis and properties of contrast agents as well as the indications, limitations and future potential of contrast-enhanced functional and molecular ultrasound.

Using NIRS technique is an elegant and very precise, this technique become more frequently used for determining physico-chemical properties of feed, especially chemical composition (dry matter, protein, ash, fiber, fat, non-nitrogenous extractive substances. The contents of dry matter, crude protein, crude ash, crude fiber, crude fat, non – nitrogenous extractive substances of maize are determined by destructive methods and then using them was build the calibration curve for NIRS with which we will determine all the chemical properties of the material using prediction.
 This paper aims to highlight a way of direct analysis method undestructive of crude protein, crude fat, crude fiber, crude ash, non-nitrogenous extractive substances using near infrared spectrometry technique in conjunction with reflected attenuated total. For each property we have used these method assessment: for the crude protein was used Kjeldahl method, for crude fat was used Soxhlet method, for crude ash performed Hennenberg – Stohmann method, for crude fiber was used Hennenberg - Stohmann method and for non – nitrogenous extractive substances was used mathematical calculation. All these results determined by the classical method, the destructive method, were used to build the calibration curve for device FT-NIR Spectrometer Perkin Elmer Spectrum 100 N with accessory N NIRA. Mathematical model was built using the near infrared spectrofotoscopiei technique in conjunction with multivariable calibration techniques using the Perkin Elmer program Spectrum Quant + 4.60. The method provides a rapid and reliable alternative to traditional quantitative methods for determining which usually requires several hours to complete.

Destructive and non-destructive methods have been used for the determination of microtraces of antimony in high-purity silicon powder. The destructive method was based on substoichiometric radioactivation analysis with solvent extraction using BPHA and cupferron as organic reagents. The antimony contents in high-purity silicon can be determined by the proposed method.

Context: The compressibility and compatibility of a powder formulation is usually determined by compaction and following destructive tensile strength and relative density measurement of the final compact.Objective: In this study, a non-destructive method with Near-Infrared Spectroscopy (NIRS) was designed and evaluated for the measurement of powder compressibility and compactibility.Materials and Methods: 12 different formulations with a wide range of difference in properties were investigated by compaction and analysis of the resulting tablets. Two similar tablet batches were produced with every formulation. Relative density and tensile strength were measured with the traditional, destructive method on one tablet batch while a newly developed non-destructive chemometric NIRS method was applied for the second batch. The outcomes of the two approaches were compared to validate the developed method. All data sets were applied to three established mathematical equations to calculate equation factors, which are claimed to represent the formulation compressibility and compactibility. The study focus was set on the equation factor value comparison between the traditional and the newly designed method.Results & Discussion: The results showed a high similarity between the outcomes of the two methods. An essential difference was noticed for the outcomes of the equation factors after application to the Leuenberger equation.Conclusion: The approach with the NIRS is suggested as a promising tool for a reliable inline quality monitoring in the tablet manufacturing process.

Milk adulteration poses a global concern, with developing countries facing higher risks due to unsatisfactory monitoring systems and policies. Surprisingly, this common issue has often been overlooked in many countries. Contrary to popular belief, adulterants in milk can result in severe health risks, potentially leading to fatal diseases. Detecting and categorizing milk adulteration is crucial for consumer safety and the dairy industry. This research is divided into 2 breakthroughs, destructive and nondestructive methods. In the destructive method, the Lactoscan system was used for qualitative analysis: SNF, density, fat, lactose, conductivity, solids, protein, temperature, and pH level. The research also examines nondistractive hyperspectral imaging (HSI) through HSI Specim Fx-10 (397-1,003 nm; Specim, Spectral Imaging Ltd., Oulu, Finland) analysis to detect various phases of milk adulteration for accurate and user-friendly imaging-based adulterant detection and categorization. Preprocessing involves radiometric correction, image resizing, region of interest selection for feature extraction, and empirical line method to calculate spectral reflectance signature. Machine learning techniques (logistic regression, decision tree, support vector machine, and linear discriminant analysis [LDA]), are employed, with LDA excelling in adulteration identification by learning the spectral signatures. These algorithms are trained and validated using a developed milk adulteration dataset. Training, testing, and validation accuracy, precision, recall, F1 score, kappa, and Matthew's correlation coefficient metrics showcase the effectiveness of the proposed pipeline, outclassing numerous state-of-the-art approaches with a validation accuracy of 100%. In conclusion, this study established a multiclass model capable of detecting milk adulterant behavior, showing significant practical application for milk quality assessment.

Damage due to creep and plastic flow is assessed using destructive and non-destructive methods in steels (40HNMA and P91). In the destructive methods the standard tension tests were carried out after prestraining and variations of the selected tension parameters were taken into account for damage identification. In order to assess a damage development during the creep and plastic deformation the tests for both steels were interrupted for a range of the selected strain magnitudes. The ultrasonic and magnetic techniques were used as the non-destructive methods for damage evaluation. The last step of the experimental programme contained microscopic observations. A very promising correlation between parameters of methods for damage development evaluation was achieved. It is well proved for the ultimate tensile stress and birefringence coefficient.

This paper presents an experimental examination of the effect of high temperatures on concrete prepared with different fibers types. For this study the concrete were prepared with four types of fibers (Steel, polypropylene, carbon and the combination of several types of fibers) and water/cement ratio fixed (w/c of 0.35). Specimens were heated under five different temperatures: 20 °C (ambient temperature), of 200 ºC, 300, 400 ºC and 600 ºC respectively. The following settings: compressive strength, ultrasonic pulse velocity, rebound hammer, concrete mass loss, and water porosity were examined in this Research experimental. Also A scanning electron microscopy study was used to comprehend the change in texture. The cracks were also examined using a microscope and other methods. This article is a contribution to the general understanding of the impact of fibers in high temperature concrete and highlights the significant impact of different types of fibers on the physical and mechanical properties of concrete who they were explore using destructive and nondestructive methods.

Commonly the quality of dragon fruit in Indonesia is determined manually by using visual appearances and it gives un-uniformly results caused by human factors and the judgement is not reflected the internal quality of dragon fruit. Destructive method is usually used to determine the internal quality of dragon fruit that is unsuitable for quality control of fresh dragon fruit. So a non destructive method is required for evaluation the quality of dragon fruit. The objectives of the research were to determine the physico-chemical and ultrasound wave transmission characteristics of super red dragon fruit according to harvesting time, and to study the relationship between ultrasound wave transmission characteristics and physico-chemical characteristics of super red dragon fruit. Super-red dragon fruits were harvested at 30, 32, and 34 days after flower blooms (150 samples) from PT Wahana Cory, Ciapus, Bogor. The results showed that the ultrasound velocity of super red dragon fruit ranged from 614.10 to 680.16 m/s and the attenuation coefficient were 57.32 to 62.40 Neper per meter. The attenuation coefficient was significantly different according to maturity. There were significant correlations between ultrasound parameters (velocity and attenuation coefficient) and physico-chemical of super red dragon fruit (firmness, sugar content, total soluble solid, and total acid).Keyword: dragon fruit, attenuation, ultrasound, velocity Diterima: 25 September 2009; Disetujui: 3 Februari 2010

The search of a durable and low cost fiber reinforced cement concrete for construction works is an empirical challenge in developing countries. Economic scarcity have confined the use of carbon fibers in cementitious composites on a commercial level. Jute fiber has the potential to be used in reinforcement to surpass the inherent deficiencies in cementitious materials. In this research, jute fiber reinforced concrete is used to find out which test method is more reliable among destructive and non-destructive test methods. In recent years, one of the most challenging scientific method is intelligent defect detection. Non Destructive Testing (NDT) techniques are the most useful and the easiest methods due to their efficiency and low cost. The experimental process using Ultrasonic Pulse Velocity and Schmidt Rebound Hammer as Non-destructive Tests (NDT) are used in this paper to set up a correlation between the compressive strengths of compression tests and NDT values. These two tests have been used to find out the concrete quality by applying regression analysis models between compressive strength of jute fiber reinforced concrete and tests values. The relationship between compression strength of concrete collected from destructive test method and estimated results from NDT’s records using regression analysis are compared together to assess their reliability of prediction of concrete strength. The test results show that destructive test methods are the most reliable way to find out the original strength of test specimens. After destructive test methods, the rebound number method is more efficient in predicting the strength of concrete under certain conditions. Schmidt Hammer rebound tests is recommended to estimate the strength of concrete to reduce the number of cores taken from the structures in practical cases.

Αντικείμενο της παρούσας διατριβής αποτελεί η διερεύνηση του φαινομένου των καταπτώσεων βράχων και ειδικότερα των επιμέρους παραμέτρων που επιδρούν στη διαμόρφωση της τιμής των συντελεστών απομείωσης ενέργειας - αναπήδησης (κάθετου R_N και εφαπτομενικού R_T). Η έρευνα εστιάστηκε σε αριθμητικές προσομοιώσεις που έγιναν σε 34 συγκεκριμένες θέσεις του Ελληνικού χώρου, όπου έχουν καταγραφεί σοβαρά περιστατικά - γεγονότα καταπτώσεων, αρκετά από τα οποία είχαν σοβαρές κοινωνικές επιπτώσεις και επέφεραν βλάβες σε τεχνικά έργα. Η επιλογή των περιοχών βασίστηκε στη συχνότητα αλλά και στην αναμενόμενη επικινδυνότητα βραχοπτώσεων. Στη δυτική και κεντρική Ελλάδα εντοπίζεται η μεγαλύτερη συγκέντρωση των φαινομένων. Η ανάπτυξη εκεί των μεγάλων απωθήσεων του Ελλαδικού χώρου, έχει αποτέλεσμα ασβεστολιθικοί σχηματισμοί να βρίσκονται υπερκείμενοι του φλύσχη. Κατά μήκος της επαφής των σχηματισμών, εντοπίζεται ο μεγάλος όγκος κατολισθητικών φαινομένων και βραχοπτώσεων. Τα συγκριτικά μεγαλύτερα ύψη βροχόπτωσης αφενός και αφετέρου η ανάπτυξη των οικισμών στη γραμμή επαφής, συντελούν στην αυξημένη επικινδυνότητα. Αντίθετα, στο ανατολικό τμήμα της χώρας, όπου κυριαρχούν συμπαγή κρυσταλλοσχιστώδη πετρώματα μεγάλου πάχους, εμφανίζονται λιγότερο συχνά καταπτώσεις βράχων είναι όμως φαινόμενα πιο βίαια και μεγάλης έκτασης. Στις συγκεκριμένες θέσεις έγινε συστηματική τεχνικογεωλογική έρευνα, λεπτομερής αποτύπωση και καταγραφή όλων των τεχνικογεωλογικών παραμέτρων, καθώς επίσης και των επιμέρους χαρακτηριστικών των φαινομένων (αποτυπώσεις πρανών, σημεία αναπηδήσεων βραχοτεμαχών, μορφή τροχιών, όγκοι και σχήμα βραχοτεμαχών κλπ). Η προσέγγιση και ο έλεγχος - εκτίμηση των συντελεστών απομείωσης ενέργειας βασίστηκε σε μεθόδους αντίστροφης (ανάδρομης) ανάλυσης επί των πραγματικών χαρακτηριστικών των γεγονότων - συμβάντων καταπτώσεων. Έγινε με τη χρήση του λογισμικού Rocfall (Rocscience Inc.) το οποίο αποτελεί ένα από τα πλέον ευρέως χρησιμοποιούμενα λογισμικά προσομοίωσης καταπτώσεων. Οι αρχικές αναλυτικές προσομοιώσεις έδειξαν ότι η εκτίμηση των συντελεστών αναπήδησης μπορεί να ικανοποιούσαν τις επιτόπου καταγεγραμμένες συνθήκες (αποστάσεις των σημείων αναπήδησης του βραχοτεμάχους), όμως η τροχιά που πραγματικά ακολουθήθηκε να έχει διαφορετικά χαρακτηριστικά (π.χ. ύψος αναπήδησης) που σημαίνει διαφοροποίηση στις τιμές των συντελεστών. Προς την κατεύθυνση αυτή, αναπτύχθηκε ένα υπολογιστικό μοντέλο ακριβέστερου προσδιορισμού της αναμενόμενης τροχιάς, λαμβάνοντας επιπλέον υπόψη τον κινηματικό χαρακτήρα της και κυρίως τη γωνιακή ταχύτητα και τη στροφορμή του βραχοτεμάχους που επιβάλλουν τη διαμόρφωσή της (π.χ. πιο επίπεδη τροχιά και με χαμηλότερο ύψος αναπήδησης). Για τη σύνταξη και τη δημιουργία του συγκεκριμένου κώδικα χρησιμοποιήθηκε το λογισμικό Mathematica(Wolfram). Το συγκεκριμένο μοντέλο το οποίο βασίζεται στην μελέτη της αναπήδησης βραχοτεμάχους, ονομάστηκε για λόγους συντομίας ana-rock. Το προτεινόμενο υπολογιστικό μοντέλο λειτουργεί συνεπικουρώντας την αντίστροφη ανάλυση για τον προσδιορισμό των συντελεστών απομείωσης ενέργειας, καθόσον με τη χρήση αυτού, μπορούν να ενταχθούν στους υπολογισμούς τόσο η περιστροφική κίνηση που αναπτύσσει το βραχοτέμαχος, όσο και τα ενδιάμεσα τμήματα της συνολικής τροχιάς της κατάπτωσης. Με το συγκεκριμένο μοντέλο έγινε προσαρμογή των συντελεστών που εκτιμήθηκαν μέσω της αντίστροφης ανάλυσης, σε όλες τις περιοχές έρευνας και συγχρόνως επαλήθευση της εφαρμοσιμότητάς του σε συνθήκες πεδίου. Αποτέλεσμα ήταν να προκύψουν πιο ρεαλιστικές τροχιές κατά την προσομοίωση και συνεπώς «διορθωμένες» τιμές συντελεστών αναπήδησης, οι οποίες είναι καλύτερα προσαρμοσμένες στις τοπικές συνθήκες. Από την επεξεργασία των αποτελεσμάτων για όλες τις θέσεις έρευνας προκύπτουν κάποιες αξιοσημείωτες συσχετίσεις μεταξύ των συντελεστών απομείωσης ενέργειας (κυρίως του R_N) και βασικών τεχνικογεωλογικών παραμέτρων (γεωλογικός δείκτης αντοχής GSI, κλίση και λιθολογία πρανών, σχήμα βραχοτεμαχών), οι οποίες καταδεικνύουν και πιστοποιούν την καθοριστική σημασία της έρευνας πεδίου στην αξιοπιστία των αναλυτικών προσεγγίσεων.

Additive manufacturing is remarkably suitable for creating high complexity performance parts. An added benefit of the Directed Energy Deposition (DED) process is the ability to make functionally graded materials. This expansion of the design and manufacturing spaces presents a challenge for the non-destructive evaluation of AM parts. Hybrid AM parts are an example of functionally graded materials for which the variation in microstructure and material properties across the bulk of the parts is created through a combination of manufacturing processes. In this work, a hybrid 420 stainless steel coupon was created using the DED method, and a surface treatment was applied between added layers. Characterization using destructive and non-destructive methods was performed. The microstructure, hardness profile, phase velocity, attenuation, and backscatter results from the hybrid coupon are compared with those from an AM coupon and a wrought coupon. Agreement between destructive and non-destructive measurements is studied. Furthermore, ultrasonic non-destructive methods are shown to be effective for identifying the gradient in the material properties of the hybrid coupon. The work hereby presented can further inform non-destructive evaluation decisions for hybrid AM parts.Additive manufacturing is remarkably suitable for creating high complexity performance parts. An added benefit of the Directed Energy Deposition (DED) process is the ability to make functionally graded materials. This expansion of the design and manufacturing spaces presents a challenge for the non-destructive evaluation of AM parts. Hybrid AM parts are an example of functionally graded materials for which the variation in microstructure and material properties across the bulk of the parts is created through a combination of manufacturing processes. In this work, a hybrid 420 stainless steel coupon was created using the DED method, and a surface treatment was applied between added layers. Characterization using destructive and non-destructive methods was performed. The microstructure, hardness profile, phase velocity, attenuation, and backscatter results from the hybrid coupon are compared with those from an AM coupon and a wrought coupon. Agreement between destructive and non-destructive measurements is ...

O objetivo deste trabalho foi avaliar a resistência e elasticidade em flexão estática em painéis LVL produzidos com lâminas pré-classificadas de Eucalyptus grandis W. Hill ex Maiden de diferentes idades. Foram selecionadas 15 árvores, sendo oito com idade de 15 anos e sete com idade 20 anos, processadas em torno laminador e em seguida pré-classificadas não destrutivamente. Foram geradas três classes de rigidez para 15 anos e três para 20 anos, sendo os painéis produzidos dentro de cada classe. Para avaliar o confronto intraclasses de rigidez, foi realizada uma Anova a 95% de probabilidade, e um teste de médias de Tukey a 95 % de significância. Para o mor foi observada uma relação direta entre as classes de rigidez, ou seja, com o aumento da classe houve uma resposta direta na variável. O efeito é observado tanto na idade de 15 quanto de 20 anos. O moe teve comportamento semelhante à densidade dos painéis. Para a idade de 15 anos, existe relação direta entre as classes de rigidez e valores do moe. Na idade de 20 anos não houve relação entre moe e classe de rigidez. Assim, a propriedade avaliada indica a possibilidade de produção, em escala comercial, de painéis com características diferenciadas por classe de rigidez.