Printability of calcium phosphate: Calcium sulphate powders for the application of tissue engineered bone scaffolds using the 3D printing technique

In this study, calcium phosphate (CaP) powders were blended with a three-dimensional printing (3DP) calcium sulfate (CaSO4)-based powder and the resulting composite powders were printed with a water-based binder using the 3DP technology. Application of a water-based binder ensured the manufacture of CaP:CaSO4 constructs on a reliable and repeatable basis, without long term damage of the printhead. Printability of CaP:CaSO4 powders was quantitatively assessed by investigating the key 3DP process parameters, i.e. in-process powder bed packing, drop penetration behavior and the quality of printed solid constructs. Effects of particle size, CaP:CaSO4 ratio and CaP powder type on the 3DP process were considered. The drop penetration technique was used to reliably identify powder formulations that could be potentially used for the application of tissue engineered bone scaffolds using the 3DP technique. Significant improvements (p < 0.05) in the 3DP process parameters were found for CaP (30-110 μm):CaSO4 powders compared to CaP (< 20 μm):CaSO4 powders. Higher compressive strength was obtained for the powders with the higher CaP:CaSO4 ratio. Hydroxyapatite (HA):CaSO4 powders showed better results than beta-tricalcium phosphate (β-TCP):CaSO4 powders. Solid and porous constructs were manufactured using the 3DP technique from the optimized CaP:CaSO4 powder formulations. High-quality printed constructs were manufactured, which exhibited appropriate green compressive strength and a high level of printing accuracy.

Investigating Approaches to Three-Dimensional Printing of Hydroxyapatite Scaffolds for Bone Regeneration

This study investigated the feasibility of manufacturing hydroxyapatite (HA)-based scaffolds using 3D printing technology by incorporating different binding additives, such as maltodextrin and polyvinyl alcohol (PVOH), into the powder formulation. Different grades of PVOH were evaluated in terms of their impact on the printing quality. Results showed that scaffolds with high architectural accuracy in terms of the design and excellent green compressive strength were obtained when the PVOH (high viscosity) was used as the binding additive for HA.

Inkjet printing of resistively loaded FSS for microwave absorbers

Inkjet printing is proposed as a means to create the resistively loaded elements of a frequency selective surface (FSS) which suppresses radar backscatter when placed above a metal ground plane. Spectral transmission and reflection measurements from 9 to 18 GHz show that the dot density of the printed features and the volume ratio of an aqueous vehicle and nano-silver (Ag) ink mixture can be selected to obtain surface resistances in the range 1.2-200 Ω/sq.

Commentary on Henrician Proclamation 1538:A Proclamation Prohibiting Unlicensed Printing of Scripture (1538)

Royal Proclamation prohibiting the printing and publishing of ecclesiastical and other books without prior licence, as well as the importation, sale and publication of English language texts printed on the continent. This Proclamation established the precedent for the pre-publication licensing of literary works in England.
The commentary describes the background to the Proclamation, in particular the significance of the English Reformation, and Henry VIII's increasing interest in regulating and censuring the press. The commentary suggests that while this early instance of press intervention influenced governmental attitudes to censorship throughout the next 150 years, one of the crucial differences between this and later models of ideological control was that the 1538 Proclamation sought to censure print materials in a manner that was decoupled from the economic ownership and exploitation of such works.

Commentary on early Tudor printing privileges 1553: Totell's Printing Patent (1553)

One of the earliest examples of work printed by Richard Pynson, the King's Printer between 1508 and 1530, to make reference to the fact that the work in question was printed under the protection of the King. The royal printing privilege provided one of two different models for preventing the unauthorised reproduction of works after publication which prefigured the introduction of statutory copyright in the early eighteenth century.
The commentary describes the early attitudes of the monarchy towards the regulation of the printing trade within England, and the exercise of the royal prerogative in granting printing privileges not just to the royal printer, but to other favoured subjects both in relation to individual works as well as to entire classes of work (with the latter more often referred to as printing patents).

Commentary on early Tudor printing privileges 1559: Day's privilege for The Cosmographical Glass

An early example of a printing privilege granted to protect the printing of an individual work, in this case William Conningham's The Cosmographical Glass. The commentary describes the early attitudes of the monarchy towards the regulation of the printing trade within England, and the exercise of the royal prerogative in granting printing privileges not just to the royal printer, but to other favoured subjects both in relation to individual works as well as to entire classes of work (with the latter more often referred to as printing patents).

COD removal from textile industry effluent: pilot plant studies

This work involved the treatment of industrial waste water from a nylon carpet printing plant. As dyeing of nylon is particularly difficult, acid dyes, fixing agents, thickeners, finishing agents, are required for successful colouration and cause major problems with the plant's effluent disposal in terms of chemical oxygen demand (COD). Granular activated carbon (GAC) Filtrasorb 400 was used to treat a simulated process plant effluent containing all the pollutants. Equilibrium isotherm experiments were established and experimental data obtained showed good empirical correlation with Langmuir isotherm theory. Column experimental data, in terms of COD were correlated using the bed depth service time (BDST) model. Solid phase loading in the columns were found to approach that in equilibrium studies indicating an efficient use of adsorbent. The results from the BDST model were then used to design a pilot adsorption rig at the plant. The performance of the pilot plant column were accurately predicted by scale-up from the bench scale columns. (C) 2001 Elsevier Science BN. All rights reserved.

Textile wastewater treatment using granular activated carbon adsorption in fixed beds

This work involved the treatment of industrial wastewater from a nylon carpet printing plant which currently receives no treatment and is discharged to sea. As nylon is particularly difficult to dye, acid dyes are required for successful coloration and cause major problems with the plant's effluent disposal in terms of color removal. Granular activated carbon Filtrasorb 400 was used to treat a ternary solution of acid dyes and the process plant effluent containing the dyes in a fixed-bed column system. Experimental data were correlated using the bed depth service time (BDST) model to previously published work by the authors for single dye adsorption. The results were expressed in terms of the BDST adsorption capacity, in milligrams of adsorbate per gram of adsorbent, and indicated that there was a 12-25% decrease iri adsorption capacity in the ternary system compared to the single component system; This reduction has been attributed to competitive adsorption occurring in the ternary component system. Dye adsorption from the process plant effluent showed an approximate 65% decrease in adsorption capacity compared to the ternary solution system. This has been attributed to interference caused by the other colorless textile effluent pollutants found in the process wastewater. A chemical oxygen demand analysis on these components indicated that the dyes accounted for only 14% of the total oxygen demand.

Biodegradation and biosorption of acid anthraquinone dye

The acid anthraquinone dye Tectilon Blue (TB4R) is a major coloured component from the aqueous effluent of a carpet printing plant in Northern Ireland. The aerobic biodegradation of TB4R has been investigated experimentally in batch systems, using three strains of bacteria, namely, Bacillus gordonae (NCIMB 12553), Bacillus benzeovorans (NCIMB 12555) and Pseudomonas putida (NCIMB 9776). All three strains successfully decolourised the dye, and results were correlated using Michaelis-Menten kinetic theory. A recalculation of the reaction rate constants, to account for biosorption, gave an accurate simulation of the colour removal over a 24-h period. Up to 19% of the decolorisation was found to be caused by biosorption of the dye onto the biomass, with the majority of the decolorisation caused by utilisation of the dye by the bacteria. The reaction rate was found to be intermediate between zero and first order at dye concentrations of 200-1000 mg/l. (C) 2000 Elsevier Science Ltd. All rights reserved.

Alternative antecedents, probabilities, and the suppression of fallacies in Wason's selection task

Three experiments examined the influence of a second rule on the pattern of card selections on Wason's selection task. In Experiment 1 participants received a version of the task with a single test rule or one of two versions of the task with the same original test rule together with a second rule. The probability of q was manipulated in the two-rules conditions by varying the size of the antecedent set in the second rule. The results showed a significant suppression of q card and not-p card selections in the alternative-rule conditions, but no difference as a function of antecedent set size. In Experiment 2 the size of the antecendent set in the two-rules conditions was manipulated using the context of a computer printing double-sided cards. The results showed a significant reduction of q card selections in the two-rules conditions, but no effect of p set size. In Experiment 3 the scenario accompanying the rule was manipulated, and it specified a single alternative antecedent or a number of alternative antecedents. The q card selection rates were not affected by the scenario manipulation but again were suppressed by the presence of a second rule. Our results suggest that people make inferences about the unseen side of the cards when engaging with the task and that these inferences are systematically influenced by the presence of a second rule, but are not influenced by the probabilistic characteristics of this rule. These findings are discussed in the context of decision theoretic views of selection task performance (Oaksford Chater, 1994).

Value creation and value claiming in strategic outsourcing decisions: A resource contingency perspective

This study integrates the concepts of value creation and value claiming into a theoretical framework that emphasizes the dependence of resource value maximization on value-claiming motivations in outsourcing decisions. To test this theoretical framework, it develops refutable implications to explain the firm's outsourcing decision, and it uses data from 178 firms in the publishing and printing industry on outsourcing of application services. The results show that in outsourcing decisions, resource value and transaction costs are simultaneously considered and that outsourcing decisions are dependent on alignment between resource and transaction attributes. The findings support a resource contingency view that highlights value-claiming mechanisms as resource contingency in interorganizational strategic decisions.

Sensing Spaces:A Body-oriented Architectural Design Education

The contemporary dominance of visuality has turned our understanding of space into a mode of unidirectional experience that externalizes other sensual capacities of the body while perceiving the built environment. This affects not only architectural practice but also architectural education when an introduction to the concept of space is often challenging, especially for the students who have limited spatial and sensual training. Considering that an architectural work is not perceived as a series of retinal pictures but as a repeated multi-sensory experience, the problem definitions in the design studio need to be disengaged from the dominance of a ‘focused vision’ and be re-constructed in a holistic manner. A method to address this approach is to enable the students to refer to their own sensual experiences of the built environment as a part of their design processes. This paper focuses on a particular approach to the second year architectural design teaching which has been followed in the Department of Architecture at Izmir University of Economics for the last three years. The very first architectural project of the studio and the program, entitled ‘Sensing Spaces’, is conducted as a multi-staged design process including ‘sense games, analyses of organs and their interpretations into space’. The objectives of this four-week project are to explore the sense of space through the design of a three-dimensional assembly, to create an awareness of the significance of the senses in the design process and to experiment with re-interpreted forms of bodily parts. Hence, the students are encouraged to explore architectural space through their ‘tactile, olfactory, auditory, gustative and visual stimuli’. In this paper, based on a series of examples, architectural space is examined beyond its boundaries of structure, form and function, and spatial design is considered as an activity of re-constructing the built environment through the awareness of bodily senses.