Study of the ability to field emission from diamond-like carbon layers and carbon nanotubes

The aim of this work was to study the relationship between parameters of the electron field emission and the film deposition method. In this study two methods were applied: classical radio frequency plasma-assisted chemical vapor deposition (RF PACVD) to produce diamond-like carbon (DLC) layers and chemical vapor deposition (CVD) to produce carbon nanotubes (CNT). DLC layers were grown on n-type silicon substrates and CNT were grown on n-type and p-type silicon substrates.Atomic force microscopy (AFM) and Raman spectroscopy were used to investigate the physical and chemical parameters of DLC films after deposition process. The electrical parameters of capacitors with the DLC layer as an insulator were extracted from the capacitance-voltage (C-V) and current-voltage (I-V) characteristics. Measurements of the field emission were performed after characterization of the layer properties.     

UV‐assisted screen‐printing of flat textiles

An approach to printing of flat textiles is presented in this work. A screen‐printing method was applied on a cotton fabric. An aqueous printing paste was prepared from thickening and crosslinking agents and an ultraviolet‐sensitive tetrazole ring‐based compound of 2,3,5‐triphenyltetrazolium chloride or nitrotetrazolium blue chloride. After the printing process, a pattern was just visible with the naked eye. The development of colour occurred after exposure of the textile to ultraviolet light of 253.7 nm and was caused by the transformation of 2,3,5‐triphenyltetrazolium chloride or nitrotetrazolium blue chloride salts into the corresponding formazans, which are insoluble in water. The printed designs were resistant to washing. The stability of the colour of the samples is discussed in the case of prolonged irradiation, both with ultraviolet light of 253.7 nm and with daylight. This method of printing is a recent proposition for creative textile designing. It also seems to indicate a likely type of dye that may be further developed as potentially attractive for ultraviolet‐assisted printing or dyeing of textiles.     

Composite connections in slim-floor system: An experimental study

This paper reports the results of full-scale tests in beam-to-column connections for composite slim floor systems, including tests on Bare Steel connection and composite connection. The tested system consists of a concrete-filled composite column and a composite floor where an asymmetric steel beam is connected to a composite column by shear steel plates. Tests results previously obtained on partially encased composite beams were used to define the position of the headed studs in the slim floor system. Based on the obtained results of connections, the composite and Bare Steel connection behaved as semi-rigid and nominally pinned respectively. The tests results also indicated a significant contribution of the slim floor to the moment capacity of the connection.     

Assessment of a regulatory sanitization process in Egyptian dairy plants in regard to the adherence of some food-borne pathogens and their biofilms

Food-borne pathogens may develop certain strategies that enable them to defy harsh conditions such as chemical sanitization. Biofilm formation represents a prominent one among those adopted strategies, by which food-borne pathogens protect themselves against external threats. Thus, bacterial biofilm is considered as a major hazard for safe food production. This study was designed to investigate the adherence and the biofilm formation ability of some food-borne pathogens on stainless steel and polypropylene surfaces using chip assay, and to validate regular sanitizing process (sodium hypochlorite 250mg/L) for effective elimination of those pathogens. Sixteen pathogenic bacterial strains, previously isolated from raw milk and dairy products at Zagazig city, Egypt (9 Staphylococcus aureus, 4 Cronobacter sakazakii and 3 Salmonella enterica serovar Typhimurium), were chosen for this study. Strains showed different patterns of adherence and biofilm formation on tested surfaces with minor significance between surfaces. The ability of sodium hypochlorite to completely eradicate either adhered or biofilm-embedded pathogens varied significantly depending on the strain and type of surface used. Whilst, sodium hypochlorite reduced tested pathogens counts per cm(2) of produced biofilms, but it was not able to entirely eliminate neither them nor adherent Cronobacter sakazakii to stainless steel surface. This study revealed that biofilm is considered as a sustainable source of contamination of dairy products with these pathogens, and also emphasized the need of paying more attention to the cleaning and sanitizing processes of food contact surfaces.     

Development of oxidised and heat-moisture treated potato starch film

This study investigated the effects of sodium hypochlorite oxidation and a heat-moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat-moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch.     

Short communication: Principal components and factor analytic models for test-day milk yield in Brazilian Holstein cattle

A total of 46,089 individual monthly test-day (TD) milk yields (10 test-days), from 7,331 complete first lactations of Holstein cattle were analyzed. A standard multivariate analysis (MV), reduced rank analyses fitting the first 2, 3, and 4 genetic principal components (PC2, PC3, PC4), and analyses that fitted a factor analytic structure considering 2, 3, and 4 factors (FAS2, FAS3, FAS4), were carried out. The models included the random animal genetic effect and fixed effects of the contemporary groups (herd-year-month of test-day), age of cow (linear and quadratic effects), and days in milk (linear effect). The residual covariance matrix was assumed to have full rank. Moreover, 2 random regression models were applied. Variance components were estimated by restricted maximum likelihood method. The heritability estimates ranged from 0.11 to 0.24. The genetic correlation estimates between TD obtained with the PC2 model were higher than those obtained with the MV model, especially on adjacent test-days at the end of lactation close to unity. The results indicate that for the data considered in this study, only 2 principal components are required to summarize the bulk of genetic variation among the 10 traits.     

Interactions of enological tannins with the protein fraction of saliva and astringency perception are affected by pH

The effects of pH on both tannin-induced astringency and tannin–salivary protein interactions were investigated. A trained sensory panel evaluated astringency perception. Tannin–salivary protein interactions were assessed in vitro by examining the effects of either a condensed enological tannin or an hydrolyzable enological tannin on two physicochemical properties of the protein fraction of saliva, namely, its mode of diffusion on cellulose membranes and its precipitation. Comparative assays mimicking the degree of dilution experienced by saliva during a tasting assay were performed at pH 3.5 and pH 7.0. Results indicated that both enological tannins were perceived as clearly more astringent at pH 3.5 compared with pH 7.0. In addition, the effects of tannins on protein diffusion and protein precipitation were markedly exacerbated at pH 3.5.     

Resistant starch and thermal,morphological and textural properties of heat‐moisture treated rice starches with high‐, medium‐ and low‐amylose content

This study investigated the effects of heat‐moisture treatment (HMT) on the resistant starch content and thermal, morphological, and textural properties of rice starches with high‐, medium‐ and low‐amylose content. The starches were adjusted to 15, 20 and 25% moisture levels and heated at 110°C for 1 h. The HMT increased the resistant starch content in all of the rice starches. HMT increased the onset temperature and the gelatinisation temperature range (T_finish–T_onset) and decreased the enthalpy of gelatinisation of rice starches with different amylose contents. This reduction increased with the increase in the moisture content of HMT. The morphology of rice starch granules was altered with the HMT; the granules presented more agglomerated surface. The HMT affected the textural parameters of rice starches; the high‐ and low‐amylose rice starches subjected to 15 and 20% HMT possessed higher gel hardness.