Priprema nanokompozitnih filmova od polietilena niske gustoće i cinkovog oksida za produljenje trajnosti svježih jagoda

Strawberries have a very short post-harvest life mostly due to their relatively high water content, intense metabolic activity and susceptibility to microbial rot. Antimicrobial low-density polyethylene nanocomposite films containing ZnO nanoparticles at different mass fractions were prepared by melt mixing and followed by compression moulding using a hot press machine. Fresh strawberries were packed in nanocomposite films and stored at 4 °C. Their microbial stability, ascorbic acid content and titratable acidity were evaluated after 0, 4, 8, 12 and 16 days of storage. Microbial growth rate was significantly reduced up to 16 days as a result of the use of nanocomposite packaging material containing ZnO nanoparticles. By increasing the ZnO nanoparticle mass fraction to 5 %, the antimicrobial activity of the film increased. All packages containing the ZnO nanoparticles kept the microbial load of fresh strawberries below the level that affects shelf life (5 log CFU/g) up to 16 days. The lowest degradation of ascorbic acid content (6.55 mg per 100 g), and loss of acidity (0.68 %) were observed in packages containing 3 % of ZnO nanoparticles with 10 % polyethylene-grafted maleic anhydride.Jagode imaju vrlo kratak vijek trajanja zbog relativno velikog udjela vlage, pojačane metaboličke aktivnosti i podložnosti truljenju. Antimikrobni nanokompozitni filmovi pripremljeni su umješavanjem različitih masenih udjela nanočestica cinkovog oksida u polietilen niske gustoće te izravnim prešanjem u kalupu. Svježe su jagode pakirane u nanokompozitne filmove i uskladištene na 4 °C. Mikrobiološka stabilnost, udjel askorbinske kiseline i titracijska kiselost jagoda mjereni su na početku skladištenja te nakon 4, 8, 12 i 16 dana. U pakovinama od nanokompozitnog filma s česticama cinkovog oksida bitno je usporen rast mikroorganizama tijekom perioda skladištenja do 16 dana. Povećanjem masenog udjela nanočestica cinkovog oksida na 5 % povećao se i antimikrobni učinak filma. U svim pakovinama s nanočesticama cinkovog oksida broj je stanica mikroorganizama bio dovoljno malen (5 log CFU/g) da ne utječe na održivost jagoda tijekom 16 dana skladištenja. U pakovinama s 3 % nanočestica cinkovog oksida i 10 % polietilena modificiranog s maleinskim anhidridom najmanje se smanjio udjel askorbinske kiseline (za 6,55 mg u 100 g) te titracijska kiselost (za 0,68 %)

Modeling Productivity losses Due to Change Orders

Change orders are an integral part of construction projects regardless of project size or complexity. Changes may cause interruption to the unchanged scope of work and working conditions and, if poorly managed, may be detrimental to project success. Many studies have been carried out to quantify the impact of change orders on construction labour productivity, with varying degrees of accuracy and variables considered. These studies reveal that quantifying loss of productivity due to change orders is not an easy task and requires a comprehensive and holistic method. There are several methods for quantifying loss of productivity, such as measured mile analysis (MMA) and the total cost method (TCM). Although measured mile analysis (MMA) is a well-known and widely accepted method for quantifying the cumulative impact of change orders on labour productivity, it is not readily applicable to many cases. In this research two models were developed to quantify losses arising from change orders. The first model does not account for the timing of change orders, but the second model considers the timing of change orders on labour productivity. Two models were developed and tested utilizing artificial neural networks and two sets of data collected by others in that field. The two datasets were statistically analyzed and preprocessed in order to transfer the data to normal distribution form and eliminate insignificant variables considered in their development. Using best subset regression, a total of seventeen variables were reduced to nine variables accordingly. Also, the study datasets were categorized into three types of timing periods; early change, normal change and late change to create the timing model. This was implemented to enable a comparison with models developed by others. Three types of artificial neural network techniques were experimented with and evaluated for possible use in the developed models. These three types are Feed Forward Neural Network, Cascade Neural Network, and Generalized Regression Neural Network. Candidate techniques were evaluated and analyzed by neural network parameters and analysis of variance (ANOVA) to select the most efficient type of neural networks, and subsequently using it to develop two models; one considers timing and the second does not. The analysis performed led to the selection of the cascade neural network for the development of the two models productivity losses due to change orders. The developed models were tested and validated utilizing several actual cases reported by others. The models were applied to a number of cases and the results were compared to those generated by frequently cited models to demonstrate their accuracy. The comparison outcome showed that the developed models can generate more accurate and satisfactory results than those of reported in previous studies

Study on Formalism of Cultural Propaganda in Iranian Graphic since 2001 to 2011

Formalism in graphics has a different definition сompared to the other branches of art. With regard to knowing graphics unlike other arts separate from two parts of form and content, formalism in graphics is known with superiority of form over content in the initial definition. Effectiveness and misperceptions from formalist view are contradicted with definition for graphics. This improper insight which caused undermining has been regarded as one of the most important functions of advertising especially commercial advertising graphics, i.e. transmission of message. With regard to the relationship between form and content existing in formalism school and comparison of this concept with misperceptions from formalism in graphics, the present research intends to specify the relationship between form and content in cultural formalistic propaganda in Iran during 2001-2011 by collecting data via library and field method and analyzing and defining a series of works as statistical population with the purpose of examining extremism and lack of the graphic designers’ awareness from background of formalism and expression of the relationship between formation and the process governing the formalism of cultural propaganda in Iranian graphic. In this regard, to sum up the relationship between form and content in formalism of cultural propaganda in Iranian graphic at the mentioned period in most of cases can be determined as an intelligent, systematic and creative relationship with an aesthetic insight. This relationship indicates the insight far from extremism by the designers at the mentioned period to proper meaning and definition of formalism at visual schools

Reproducibility of global and segmental myocardial strain using cine DENSE at 3 T: a multicenter cardiovascular magnetic resonance study in healthy subjects and patients with heart disease

BACKGROUND: While multiple cardiovascular magnetic resonance (CMR) methods provide excellent reproducibility of global circumferential and global longitudinal strain, achieving highly reproducible segmental strain is more challenging. Previous single-center studies have demonstrated excellent reproducibility of displacement encoding with stimulated echoes (DENSE) segmental circumferential strain. The present study evaluated the reproducibility of DENSE for measurement of whole-slice or global circumferential (Ecc), longitudinal (Ell) and radial (Err) strain, torsion, and segmental Ecc at multiple centers. METHODS: Six centers participated and a total of 81 subjects were studied, including 60 healthy subjects and 21 patients with various types of heart disease. CMR utilized 3 T scanners, and cine DENSE images were acquired in three short-axis planes and in the four-chamber long-axis view. During one imaging session, each subject underwent two separate DENSE scans to assess inter-scan reproducibility. Each subject was taken out of the scanner and repositioned between the scans. Intra-user, inter-user-same-site, inter-user-different-site, and inter-user-Human-Deep-Learning (DL) comparisons assessed the reproducibility of different users analyzing the same data. Inter-scan comparisons assessed the reproducibility of DENSE from scan to scan. The reproducibility of whole-slice or global Ecc, Ell and Err, torsion, and segmental Ecc were quantified using Bland-Altman analysis, the coefficient of variation (CV), and the intraclass correlation coefficient (ICC). CV was considered excellent for CV ≤ 10%, good for 10%  40. ICC values were considered excellent for ICC > 0.74, good for ICC 0.6 < ICC ≤ 0.74, fair for ICC 0.4 < ICC ≤ 0.59, poor for ICC < 0.4. RESULTS: Based on CV and ICC, segmental Ecc provided excellent intra-user, inter-user-same-site, inter-user-different-site, inter-user-Human-DL reproducibility and good-excellent inter-scan reproducibility. Whole-slice Ecc and global Ell provided excellent intra-user, inter-user-same-site, inter-user-different-site, inter-user-Human-DL and inter-scan reproducibility. The reproducibility of torsion was good-excellent for all comparisons. For whole-slice Err, CV was in the fair-good range, and ICC was in the good-excellent range. CONCLUSIONS: Multicenter data show that 3 T CMR DENSE provides highly reproducible whole-slice and segmental Ecc, global Ell, and torsion measurements in healthy subjects and heart disease patients