Eco-friendly printing of natural fabrics using natural dyes from alkanet and rhubarb

In the present work, the suitability of printing natural fabrics (wool, silk, cotton and flax) with two natural dyes (alkanet and rhubarb) using pigment-printing technique has been investigated. The effect of different factors, i.e. dye concentration, nature of thickening agent, type of fixation, concentration and type of mordant, has been studied. The printed goods were evaluated by measuring the K/S value and the overall fastness properties. Results show that the highest K/S value was obtained by using Meypro gum as a thickener. The K/S increases rapidly as the concentration of the natural dye powder in the printing paste increases from 10 to 40 g/kg printing paste. Moreover, results show that the printed goods, which were fixed via steaming, have relatively higher colour strength than their corresponding samples fixed via thermofixation. The effect of mordants on colour development was also studied and alkanet dye was chosen as an example for this investigation. The best results were obtained by using mordant at a concentration of 20 g/kg printing paste. Different colour yields could be obtained by using different mordants, and all of colour fastness results were ranging between very well and excellent.     

Estimated daily intake of pesticide residues exposure by vegetables grown in greenhouses in Al-Qassim region,Saudi Arabia

Residues of 23 pesticides (13 insecticides, 3 fungicides, 3 herbicides, 2 acaricides, 1 rodenticide and 1 nematicide) in 160 different vegetable samples cultivated under greenhouse conditions and collected from 4 major supermarkets located in Al-Qassim region, Saudi Arabia were monitored. A multiresidue method was carried out by gas chromatography with mass spectrometry (GC–MS). Residues were found in 89 samples. Fifty four samples were found above the maximum residue levels (MRLs). The most frequently found pesticides were carbaryl followed by biphenyl and then carbofuran. MRL values exceeded most often in cabbage (11 samples) followed by squash, green pepper and carrot (7 samples each) followed by cucumber and lettuce (6 samples each), egg-plant (5 samples) and then tomato (4 samples). Also, cabbage showed the highest contamination rates (16 samples), followed by carrot, cucumber and green pepper (12 samples each), squash (11 samples), lettuce and tomato (9 samples each) and egg-plant (8 samples). The highest concentrations were determined in lettuce followed by squash, cabbage and carrot. Al-Qassim region population’s average daily intake (EDI) has been estimated between 2 × 10^?5 and 0.597 μg/kg body weight/day and the hazard index (EDI/acceptable daily intake (ADI)) less than the unity for the tested compounds. The data illustrated that the intakes are much lower than the ADIs and the exposure level to whole pesticides was below the level to produce health risk. The data indicated also the need for regular monitoring programs for pesticide residues in vegetables cultivated under greenhouse conditions, at the national level, to protect consumers’ health.     

Multiconsistency and Robustness with Global Constraints

We propose a natural generalization of arc-consistency, which we call multiconsistency: a value v in the domain of a variable x is k-multiconsistent with respect to a constraint C if there are at least k solutions to C in which x is assigned the value v. We present algorithms that determine which variable-value pairs are k-multiconsistent with respect to several well known global constraints. In addition, we show that finding super solutions is sometimes strictly harder than finding arbitrary solutions for these constraints and suggest multiconsistency as an alternative way to search for robust solutions.Supported by the Danish Research Agency (grant # 272-05-0081).Basic Research in Computer Science, funded by the Danish National Research Foundation.     

Effect of Fiber-Reinforced Polymer Wraps on Corrosion Activity and Concrete Cracking in Chloride-Contaminated Concrete Cylinders

This paper presents the results of an experimental study designed to investigate the effect of fiber-reinforced polymer (FRP) wraps on corrosion activity and concrete cracking in chloride-contaminated concrete cylinders. Thirty-five concrete cylinders, each having 102?mm diameter and 204?mm height, concentrically reinforced with one steel reinforcing bar, were subjected to accelerated corrosion exposure for 80?days. Test parameters included level of applied potential, presence of FRP wraps, and bar diameter. The corresponding current and concrete expansion were continuously monitored throughout the corrosion exposure. At the end of the test, the steel bars were extracted, cleaned of rust, and weighed to determine the actual steel mass loss. The results showed that, for the same applied fixed potential, FRP wraps effectively reduced the corresponding current, the concrete expansion, and the steel mass loss. For the same applied potential, the current density increased as the bar diameter decreased. For the same corrosion depth, the circumferential expansion of the cylinder caused by corrosion decreased as the concrete cover-to-bar diameter ratio (c/d) increased.     

Head trauma: CT scan interpretation by radiology residents versus staff radiologists

The determination of diagnostic features in recorded heart sounds was investigated with Carpentier-Edwards (CE) bioprosthetic valves. Morphological features, extracted using the Choi-Williams distribution, achieved between 96 and 61% correct classification. The time-scale wavelet-transform feature set achieved 100% correct classification with native valve populations, and 87% with the CE replacements.     

Distributed Construction of Connected Dominating Set in Wireless Ad Hoc Networks

Connected dominating set (CDS) has been proposed as virtual backbone or spine of wireless ad hoc networks. Three distributed approximation algorithms have been proposed in the literature for minimum CDS. In this paper, we first reinvestigate their performances. None of these algorithms have constant approximation factors. Thus these algorithms cannot guarantee to generate a CDS of small size. Their message complexities can be as high as O(n ²), and their time complexities may also be as large as O(n ²) and O(n ³). We then present our own distributed algorithm that outperforms the existing algorithms. This algorithm has an approximation factor of at most 8, O(n) time complexity and O(nlogn) message complexity. By establishing the (nlogn) lower bound on the message complexity of any distributed algorithm for nontrivial CDS, our algorithm is thus message-optimal.     

Stochastic modeling of polymerization in a continuous flow reactor

A stochastic approach, namely, a continuous time Markov chain (Markov process), is employed to analyze and model, in a unified fashion, both polymerization and dispersive mixing in a continuous flow reactor. Results include the distribution of numbers of active and dead polymers with chain length j both inside the reactor and at the exit. This approach can be extended to the determination of the degree of polymerization of a copolymer. Expressions are derived for the mean and variance of the number of monomers of a given type in a copolymer chain. The model can be applied to both the time homogeneous and heterogeneous processes.     

A modified method of nitric acid pulping of bagasse

Pulping of bagasse by a rapid and mild nitric acid process was successfully carried out to produce different grades of pulp. Nitric chemimechanical bagasse pulp was produced in a high yield of 91 % on pulping depithed bagasse with 4% HNO₃ for a period of 30 min at 80°C, followed by alkali pulping with 2% NaOH at 95°C for 30 min. The pulp had a satisfactory strength and high opacity. On increasing the strengths of nitric acid to 7% and alkali to 7% a nitric semichemical pulp of 65% yield was obtained. The pulp had a superior strength and high opacity. The pulp was easily bleached to 71% general electric brightness (GE) with the chlorination-alkali-extraction-hypochlorite (CEH) sequence. With 15% HNO₃ and 8% NaOH, nitric chemical bagasse pulp was produced. The pulp was easily bleached to a high brightness of 82% GE with one stage hypochlorite. The pulp had a higher strength than kraft bagasse pulp. A satisfactory newsprint paper was produced on an experimental paper machine with a furnish composed of 80% bleached nitric semichemical bagasse pulp, 10% bleached softwood pulp and 10% clay.     

Compact high-pulse-energy ultraviolet laser source for ozone lidar measurements

An all solid-state Ti:sapphire laser differential absorption lidar transmitter was developed. This all-solid-state laser provides a compact, robust, and highly reliable laser transmitter for potential application in differential absorption lidar measurements of atmospheric ozone. Two compact, high-energy-pulsed, and injection-seeded Ti:sapphire lasers operating at a pulse repetition frequency of 30 Hz and wavelengths of 867 and 900 nm, with M2 of 1.3, have been experimentally demonstrated and their properties compared with model results. The output pulse energy was 115 mJ at 867 nm and 105 mJ at 900 nm, with a slope efficiency of 40% and 32%, respectively. At these energies, the beam quality was good enough so that we were able to achieve 30 mJ of ultraviolet laser output at 289 and 300 nm after frequency tripling with two lithium triborate nonlinear crystals.     

Dependence of the Protective Concentration of a Mixture of Inhibitors from Several Reaction Series on the Polarities of Substituents in Their Molecules

Protective concentrations of mixtures of inhibitors from several reaction series (RSs), which decrease the corrosion rates a given number of times, are exponentially dependent on the sum of partial polarities of substituents in compounds belonging to the chosen RSs, provided that the total concentration of compounds for each RS is constant. The dependence is linearized in semilogarithmic log C _prvs – m coordinates.