Crack healing under sustained load in concrete: An experimental/numerical study

The need of sustainable resilient structures and infrastructures push towards the use of cementitious materials able to heal micro-cracks and defects. For real structural application under service loading the time-dependent behavior is of the utmost importance, especially in presence of cracks which can lead to a nonlinear creep behavior that might cause the structural failure. Now the new challenge is to study and quantify the effect of crack-healing on the nonlinear creep behavior. This study aims at the following goals: 1) to characterize with experimental investigations the effect of the healing in tests in which the specimens, along the exposure time and under controlled environmental conditions, are under sustained load, the expected service load, determined as a fraction of the pre-cracking load; 2) develop a comprehensive numerical framework for the interpretation and simulation of the experimentally observed results. To this purpose an experimental investigation is currently ongoing at Politecnico di Milano with reference to an Ultra High-Performance Concrete developed in the framework of the H2020 ReSHEALience project for exposure to extremely aggressive environments. The numerical framework is based on the recent developments of the multiphysics lattice particle model

Effect of Annealing and Ion Beam Irradiation on AC Electrical Properties for Gold Sputtered PM-355

171-181Deposition of different gold thickness on PM-355 cleaned by ethanol forming thin films using magnetron sputtering. Gold layer with thickness 300, 400, 500, 700, 1000, 1300, and 1500 nm were deposited to prepare Au / PM-355 thin films. Then, ac electrical properties response of thin films for a wide frequency range 20Hz - 5MHz were measured at room temperature. Meanwhile, the measurements of ac conductivity, dielectric constant, and dielectric loss factor were plotted at different frequencies to determine the optimum thickness. Hence, the comparison was done between optimum Au thickness thin films cleaned by two organic solvents and ethanol before annealing at different frequencies. Also, study the effect of annealing and ion beam that extracted radially from conical anode and disc cathode ion source on optimum Au thickness thin film electrical properties. It is found that the annealing increases both dielectric constant, dielectric loss, and ac conductivity of optimum Au thin film at different frequencies. Despite, the nitrogen ion beam effected on these thin films by decreasing the dielectric constant and ac conductivity for all thin films except the chloroform one. Finally, study the comparison between the annealing and followed by ion irradiation thin films. It is noticed the decrease in ac electrical conductivity and dielectric constant at different frequencies

Geological and geophysical investigation of Kamil crater, Egypt

We detail the Kamil crater (Egypt) structure and refine the impact scenario, based on the geological and geophysical data collected during our first expedition in February 2010. Kamil Crater is a model for terrestrial small-scale hypervelocity impact craters. It is an exceptionally well-preserved, simple crater with a diameter of 45 m, depth of 10 m, and rayed pattern of bright ejecta. It occurs in a simple geological context: flat, rocky desert surface, and target rocks comprising subhorizontally layered sandstones. The high depth-to-diameter ratio of the transient crater, its concave, yet asymmetric, bottom, and the fact that Kamil Crater is not part of a crater field confirm that it formed by the impact of a single iron mass (or a tight cluster of fragments) that fragmented upon hypervelocity impact with the ground. The circular crater shape and asymmetries in ejecta and shrapnel distributions coherently indicate a direction of incidence from the NW and an impact angle of approximately 30 to 45 . Newly identified asymmetries, including the off-center bottom of the transient crater floor downrange, maximum overturning of target rocks along the impact direction, and lower crater rim elevation downrange, may be diagnostic of oblique impacts in well-preserved craters. Geomagnetic data reveal no buried individual impactor masses >100 kg and suggest that the total mass of the buried shrapnel >100 g is approximately 1050–1700 kg. Based on this mass value plus that of shrapnel >10 g identified earlier on the surface during systematic search, the new estimate of the minimum projectile mass is approximately 5 t.Published1842–18683.8. Geofisica per l'ambienteJCR Journalrestricte

A cost effectiveness analysis of salt reduction policies to reduce coronary heart disease in four Eastern Mediterranean countries.

BACKGROUND: Coronary Heart Disease (CHD) is rising in middle income countries. Population based strategies to reduce specific CHD risk factors have an important role to play in reducing overall CHD mortality. Reducing dietary salt consumption is a potentially cost-effective way to reduce CHD events. This paper presents an economic evaluation of population based salt reduction policies in Tunisia, Syria, Palestine and Turkey. METHODS AND FINDINGS: Three policies to reduce dietary salt intake were evaluated: a health promotion campaign, labelling of food packaging and mandatory reformulation of salt content in processed food. These were evaluated separately and in combination. Estimates of the effectiveness of salt reduction on blood pressure were based on a literature review. The reduction in mortality was estimated using the IMPACT CHD model specific to that country. Cumulative population health effects were quantified as life years gained (LYG) over a 10 year time frame. The costs of each policy were estimated using evidence from comparable policies and expert opinion including public sector costs and costs to the food industry. Health care costs associated with CHDs were estimated using standardized unit costs. The total cost of implementing each policy was compared against the current baseline (no policy). All costs were calculated using 2010 PPP exchange rates. In all four countries most policies were cost saving compared with the baseline. The combination of all three policies (reducing salt consumption by 30%) resulted in estimated cost savings of $235,000,000 and 6455 LYG in Tunisia;$39,000,000 and 31674 LYG in Syria; $6,000,000 and 2682 LYG in Palestine and$1,3000,000,000 and 378439 LYG in Turkey. CONCLUSION: Decreasing dietary salt intake will reduce coronary heart disease deaths in the four countries. A comprehensive strategy of health education and food industry actions to label and reduce salt content would save both money and lives

Određivanje donepezil hidroklorida u humanoj plazmi i ljekovitim oblicima pomoću HPLC s detekcijom fluorescencije

A sensitive, isocratic reversed-phase high performance liquid chromatographic method involving fluorescence detection was developed for the determination of donepezil hydrochloride in tablets and in human plasma. Pindolol was successfully used as an internal standard. Good chromatographic separation was achieved by using analytical column C18. The system operated at room temperature using a mobile phase consisting of methanol, phosphate buffer (0.02 mol L1) and triethyl amine (pH 3.5) (55: 45: 0.5 V/V/V) at a flow rate 0.9 mL min1. The analyte and internal standard were extracted from human plasma via liquid-liquid extraction. The proposed method was validated for selectivity, linearity, accuracy and precision. The calibration curve was linear over the range of 5-2000 ng mL1 of donepezil with detection limit of 1.5 ng mL1. Intra- and inter-day relative standard deviations were less than 2.5 %. The method was found to be suitable for the quality control of donepezil hydrochloride in bulk drug as well as in human plasma.Ovaj rad opisuje HPLC metodu određivanja donepezil hidroklorida (DP) u tabletama i u ljudskoj plazmi u nano području. Postavljena je osjetljiva metoda izokratične HPLC s fluorescencijskom detekcijom. Kao unutarnji standard upotrebljen je pindolol. Dobro kromatografsko odjeljivanje postignuto je primjenom analitičke kolone C18. Radna temperatura bila je sobna, a kao mobilna faza upotrebljena je smjesa metanola, fosfatnog pufera (0,02 mol L1) i trietilamina (pH 3,5) (55:45:0.5 V/V/V). Analit i unutarnji standard su ekstrahirani iz ljudske plazme ekstrakcijom tekuće-tekuće. Predložena metoda je validirana s obzirom na selektivnost, područje linearnosti, ispravnost i preciznost. Kalibracijska funkcija bila je linearna u području od 5-2000 ng mL1 donepezila, a granica detekcije iznosila je 2 ng mL1. Relativna standardna devijacija za repetabilnost i intermedijarnu preciznost bila je manja od 2,5 %. Metoda je primjenljliva u kontroli kvalitete ljekovitih formulacija s DP-om i u praćenju DP-a u ljudskoj plazmi

Assessment of the latest prescribed drug-related problems

OBJECTIVE: Drug-related problems (DRPs) could affect patient care and lead to deleterious manifestations, therefore, this investigation aimed to review the recently published studies concerning DRPs to improve their availability to clinical pharmacists, hoping that this information will be supportive and relevant to their practice settings. MATERIALS AND METHODS: A search of Elsevier, Sage, Springer/Nature, and Wiley online libraries on Egyptian Knowledge Bank (EKB) was limited to the cumulative period from 1/1/2015 to 20/10/2020. The abstracts of 156 articles were critically reviewed and 50 articles were included based on relevance while excluding books. The selected articles reported DRPs and different strategies to reduce them. Moreover, drug-drug interactions (DDIs) in various patient populations were confirmed by many articles. Additionally, potential drug-drug interactions (pDDIs) predisposing factors were reported by others. RESULTS: 24 articles (48%) illustrated DDIs, 5 articles (10%) demonstrated ADRs, 4 articles (8%) showed medication errors (MEs), and 25 articles (50%) revealed efforts to reduce DRPs. The psychiatric population is at the utmost risk of pDDIs. Polypharmacy was the furthest recurrently reported risk factor related to DDIs. Adverse drug events (ADEs) increased healthcare costs. Different strategies to avoid DRPs were published through the stated period. CONCLUSIONS: Our findings can be supportive to healthcare professionals in enhancing their patients’ quality of care by reducing the exposure to ADEs

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty