Physical Model Method for Seismic Study of Concrete Dams

The study of the dynamic behaviour of concrete dams by means of the physical model method is very useful to understand the failure mechanism of these structures to action of the strong earthquakes. Physical model method consists in two main processes. Firstly, a study model must be designed by a physical modeling process using the dynamic modeling theory. The result is a equations system of dimensioning the physical model. After the construction and instrumentation of the scale physical model a structural analysis based on experimental means is performed. The experimental results are gathered and are available to be analysed. Depending on the aim of the research may be designed an elastic or a failure physical model. The requirements for the elastic model construction are easier to accomplish in contrast with those required for a failure model, but the obtained results provide narrow information. In order to study the behaviour of concrete dams to strong seismic action is required the employment of failure physical models able to simulate accurately the possible opening of joint, sliding between concrete blocks and the cracking of concrete. The design relations for both elastic and failure physical models are based on dimensional analysis and consist of similitude relations among the physical quantities involved in the phenomenon. The using of physical models of great or medium dimensions as well as its instrumentation creates great advantages, but this operation involves a large amount of financial, logistic and time resources

Characteristics of Concrete with Admixtures

In recent decades, tremendous success has been achieved in the advancement of chemical admixtures for Portland cement concrete. Most efforts have centered on improving the properties of concrete with minimal investments by ready-mix suppliers and contractors in the way of specialized equipment or special skills and education of their labor forces. This approach has resulted in construction cost reductions and universally accepted ready-made remedies for unexpected problems during construction. The behavior of concrete improved with superplasticizers additives is studied

Surgical tactics in acute purulent cholangitis

Catedra de chirurgie nr. 2, USMF „Nicolae Testemiţanu”, Chișinău, Republica Moldova, Conferința stiințifică „Nicolae Anestiadi – nume etern al chirurgiei basarabene” consacrată centenarului de la nașterea profesorului Nicolae Anestiadi 26 august 2016Scopul. Elaborarea managementului chirurgical în angiocolita acută purulentă. Material și metode. Prezentăm experiența clinicii în tratamentul a 645 de cazuri de colangită acută, tratați pe parcursul ultimilor 5 ani. Am recurs la tratamentul etapizat al colangitei acute purulente folosind tehnicile mini-invazive ca un standard de aur, punând accentul pe cele endoscopice (630(95%) cazuri) și foarte rar pe cele percutan-transhepatice (15(2.33%) cazuri). În cazurile extrem de grave (67(10.34%)cazuri) am fost adepții la ERCP seriate în mai multe prize cu lavajurile locale prin stend și introducerea de antibiotic local, restabilirea un grad de decompresie adecvat. Pentru pacienții extrem de dificili (15(2,26%) cazuri), suntem părtașii drenajului nazo-biliar, ce nea permis un control permanent cu lavajuri continui cu antiseptici și introducerea de antibiotici nemijlocit în CBP. Rezultate. Metodele endoscopice au permis dezobstrucția definitivă a arborelui biliar în 470(73%) cazuri. În celelalte 150(23,26%) de cazuri au permis doar o stentare(135(21%)) sau o drenare nazo-biliară(15(2,26%)) pentru asanarea colangitei purulente și cuparea sindromului icteric. Acești pacienți au beneficiat diferite intervenții chirurgicale în etapa a doua, pentru o restabilire adecvată a fluxului biliar în intestin. Mortalitatea generală a fost de 32(5%) cazuri. Concluzii. Este importantă aprecierea la justa valoare a gradului de gravitate a colangitei acute, ce permite adoptarea a unui management corect pentru fiecare caz clinic, iar aplicarea tacticii tratamentului etapizat ne va permite obținerea unor rezultate fiabile în această patologie severă.Purpose. Acute suppurative cholangitis management in appreciation. Materials and methods: There is presented clinic’s experience in the treatment of 645 cases of acute cholangitis during the last 5 years. We used the stepwise treatment of acute suppurative cholangitis using minimally invasive techniques as a gold standard, focusing on the endoscopic (630 (95%) cases) and very rarely on the percutaneous-transhepatic ones (15 (2.33%) cases). In extremely severe cases (67 (10.34%) cases) we have been for ERCP divided in steps with local lavages by stent and the introduction of local antibiotic, restoring an adequate degree of decompression. For extremely difficult patients (15 (2.26%) cases) we are partakers of nasobiliary drainage, which allowed us to control permanently with continues lavages with antiseptic and direct introduction of antibiotic in MBD. Results. The endoscopic methods allowed definitive desobstruction of the biliary tree in 470(73%) cases. In the other 150(23,26%) cases, it allowed only a stentation or a nasobiliary drainage (15(2,26%)) for sanitation of suppurative cholangitis and cutting the icteric syndrome. These patients beneficiated from different surgical interventions in the second stage for an adequate recovery of bile flow to the intestine. The general mortality was about 32(5%) cases. Conclusion. It is important to assessing the true value of the degree of severity of acute cholangitis, which allows the adoption of a right for every clinical case management and treatment tactics phased implementation will allow us to obtain reliable results in this severe disease

Surgical management in acute purulent cholangitis

Catedra de chirurgie nr. 2, USMF „Nicolae Testemiţanu”, Chişinău, Republica Moldova, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Scopul studiului a fost elaborarea managementului chirurgical în angiocolita acută purulentă. Material şi metode: Prezentăm experienţa Clinicii în tratamentul a 645 de cazuri de colangită acută, tratate pe parcursul ultimilor 5 ani. Am recurs la tratamentul etapizat al colangitei acute purulente folosind tehnicile mini-invazive ca un “standard de aur”, punând accentul pe cele endoscopice – 630 (95%) cazuri şi foarte rar pe cele percutan-transhepatice – 15 (2,33%) cazuri. În cazurile extrem de grave – 67 (10,34%), am fost adepţii la ERCP seriate în mai multe prize cu lavajurile locale prin stent şi introducerea de antibiotic local, restabilirea unui grad de decompresie adecvat. Pentru pacienţii extrem de dificili – 15 (2,26%) cazuri, suntem părtaşii drenajului nazo-biliar, ce ne-a permis un control permanent cu lavajuri continue cu antiseptice şi introducerea de antibiotice nemijlocit în calea biliară principală. Rezultate: Metodele endoscopice au permis dezobstrucţia definitivă a arborelui biliar în 470 (73%) cazuri. În celelalte 150 (23,26%) cazuri – au permis doar o stentare (n=135, ce constituie 21%) sau o drenare nazo-biliară (n=15 sau 2,26%) pentru asanarea colangitei purulente şi cuparea sindromului icteric. Aceşti pacienţi au beneficiat de diferite intervenţii chirurgicale în etapa a doua, pentru o restabilire adecvată a fluxului biliar în intestin. Mortalitatea generală a fost de 32 (5%) cazuri. Concluzii: Este importantă aprecierea la justa valoare a gradului de gravitate a colangitei acute, ce permite adoptarea unui management corect pentru fiecare pacient, iar aplicarea tacticii tratamentului etapizat ne va permite obţinerea unor rezultate fiabile în această patologie severă.Purpose: Improvement of acute suppurative cholangitis management. Material and methods: There is presented clinic’s experience in the treatment of 645 cases of acute cholangitis during the last 5 years. We used the stepwise treatment of acute suppurative cholangitis using minimally invasive techniques as a gold standard, focusing on the endoscopic – 630 (95%) cases and very rarely on the percutaneous-transhepatic ones – 15 (2.33%) cases. In extremely severe cases – 67 (10.34%) we used scheduled ERCP with local lavage through stent and the topical introduction of antibiotics, achievement of an adequate decompression. For extremely difficult patients (n=15 or 2.26% cases) we are partakers of nasobiliary drainage, which allowed us to control permanently with continues lavages with antiseptic and direct introduction of antibiotic in common biliary duct. Results: The endoscopic methods allowed definitive desobstruction of the biliary tree in 470 (73%) cases. In the other 150 (23.26%) cases, it allowed only a stentation or a nasobiliary drainage (n=15 or 2.26%) for sanation of suppurative cholangitis and elimination of jaundice. These patients beneficiated from different surgical interventions on the second stage for an adequate recovery of bile flow to the intestine. The general mortality was 32 (5%) cases. Conclusions: It is important to assessing the true value of the degree of severity of acute cholangitis, which allows the election of a correct management for every patient, whereas the scheduled treatment policy will allow us to obtain reliable results in this severe disease

Reinforced Concrete Section Design to Bending According to EN 1992-1-1/2004–EUROCODE2

In the next decades the design of the civil structures will be ruled by Eurocodes. For reinforced concrete structures the Eurocode2 will became of paramount importance to the design of the structural members. An important aspect of designing represents the relation between stress and strain to the design of the section for structural members. In this respect the EC2 defines 14 classes of concrete with different stress–strain relationships. The first stress–strain relation mentioned of EC2 for design is the parabola–rectangle stress distribution on concrete section, and further the simplified rectangle stress–strain shape is mentioned. Therefore, an aspect of the design, poorly emphasized in the national rule, is the design considering parabola–rectangle stress distribution on concrete section. The exposed issues in this paper concern with the design of the reinforced concrete section subjected to bending using two stress–strain relationships mentioned by EC2, and the differences are underlined. The design to bending using parabola–rectangle stress distribution for rectangular section is largely presented, and also the reliability for a fast designing is emphasized. Design relations for a parabola–rectangle stress distribution on section are mentioned. Also, aspects about the boundary between the single reinforcing domain and the double reinforcing domain are emphasized

Spatial prediction of soil qualitative variables using logistic regression and fuzzy techniques. Study region: Dobrovăţ basin (Central Moldavian Plateau)

The present study attempts to test the performance of two statistical approaches, namely the binary logistic regression and fuzzy techniques for spatial prediction of soil types. The study area is Dobrovăţ basin, located in NE Romania, within the Central Moldavian Plateau. The input parameters are the digital elevation model, slope, topographic wetness index, mean annual temperatures and precipitations. The logistic regression approach proved successful in estimating the spatial probabilities of Aluviosols, Chernozems, Preluvosols and Luvosols and generally failed in predicting the locations of Phaeozems. The fuzzy approach, implemented through SoLIM software, proved successful in predicting the occurrences of Aluviosols and Luvisols. On the whole, both methods managed to assign the same soil type as in the soil survey map for 55-56% of the basin. Though it is clear that the approaches need to be further improved, they do present, in the authors opinion, potential for the purpose of predicting soil qualitative variable

Spatial modelling of topsoil properties in Romania using geostatistical methods and machine learning.

Various research topics from the field of soil science or agriculture require digital maps of soil properties as input data. Such maps can be achieved by digital soil mapping (DSM) techniques which have developed consistently during the last decades. Our research focuses on the application of geostatistical methods (including ordinary kriging, regression-kriging and geographically weighted regression) and machine learning algorithms to produce high resolution digital maps of topsoil properties in Romania. Six continuous predictors were considered in our study (digital elevation model, topographic wetness index, normalized difference vegetation index, slope, latitude and longitude). A tolerance test was performed to ensure that all predictors can be used for the purpose of digital soil mapping. The input soil data was extracted from the LUCAS database and includes 7 chemical properties (pH, electrical conductivity, calcium carbonate, organic carbon, N, P, K) and the particle-size fractions (sand, silt, clay). The spatial autocorrelation is higher for pH, organic carbon and calcium carbonate, as indicated by the partial sill / nugget ratio of semivariograms, meaning that these properties are more predictable than the others by kriging interpolation. The optimal DSM method was selected by independent sample validation, using resampled statistics from 100 samples randomly extracted from the validation dataset. Also, an additional independent sample of soil profiles, comprising legacy soil data, and the 200k Romania soil map were used for a supplementary validation. The results show that machine learning and regression-kriging are the optimal methods in most cases. Among the machine learning tested algorithms, the best performance is associated with Support Vector Machines and Random Forests methods. The geographically weighted regression is also among the optimum methods for pH and calcium carbonates spatial prediction. Good predictions were achieved for pH (R2 of 0.417-0.469, depending on the method), organic carbon (R2 of 0.302-0.443), calcium carbonates (R2 of 0.300-0.330) and moderate predictions for electric conductivity, total nitrogen, silt and sand (R2 of 0.155-0.331), while the lowest prediction characterizes the phosphorous content (R2 of 0.015-0.044). LUCAS proved to be a reliable and useful soil database and the achieved spatial distributions of soil properties can be further used for national and regional soil studies

Two Novel Alliin Lyase (Alliinase) Genes from Twisted-Leaf Garlic (Allium obliquum) and Mountain Garlic (Allium senescens ssp. montanum)

Alliinase (Alliin lyase EC 4.4.1.4), a pyridoxal phosphate-dependent lyase, represents one of the major protein components of Allium species. The enzyme is a homodimeric glycoprotein and catalyzes the synthesis of allicin (diallyl thiosulfinate, a biologically active compound), pyruvate, and ammonia starting from the specific non-protein sulfur-containing amino acid alliin ((+S)-allyl-L-cysteine sulfoxide). Using newly developed specific primers two new alliinase genes from Allium obliquum and Allium senescens ssp. montanum were amplified and sequenced, as well as their homologs, from Allium fistulosum and Allium schoenoprasum. The G+C content of the alliinase region ranges between that of other dicot plants and that reported in monocot cereal plants, in all four species. Investigations of gene expression revealed a significantly higher enzyme expression level in bulbs than in leaves in all four taxa. The deduced alliinase sequences displayed a high variability among different species, since the lowest sequence similarity was found to be 55.5% between Allium senescens ssp. montanum and Allium cepa, while the highest similarity is 77.5%, between Allium senescens ssp. montanum and Allium fistulosum. Leucine is the most common amino acid in all four alliinases, while cysteine is also more frequent than in other enzymes, suggesting a high stability of the molecules due to the possible disulfide bonds