bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabrication and assessment of mechanical properties of open cell porous regular interconnected metallic structure through rapid manufacturing route
Authors: Singh Jatender Pal , Pandey Pulak Mohan 
Published: November 2017

Purpose
The requirements of open cell porous regular interconnected metallic structure (OCPRIMS) in applications such as heat exchangers, sound absorption, fluid flow control, spark arresters and biocompatible inserts have been increased. As per available technology in the present scenario, only the metallic-based rapid prototyping (RP) machines can guarantee fabrication of OCPRIMS. Metal-based RP machines are capital-intensive. So, this study aims to develop a technique for fabrication of OCPRIMS economically using three-dimensional printing (3 DP) and pressureless sintering.

Design/methodology/approach
Three computer-aided design (CAD) models of varying designed interconnected porosity 73, 70 and 60 per cent were modeled to target metallic porosity 27, 30 and 40 per cent. The same were fabricated with ceramic-based powder using 3 DP. Thereafter, spherical bronze powder with average size of 200 µm was filled and sintered in pressureless manner under inert atmosphere of argon. After sintering, the specimens were cleaned with the help of pricking needles and high-pressure water. It flushed the burnt ceramic powder and allowed metallic portion to remain intact. The obtained specimens were inverse of CAD/3 DP models. The dimensional measurement at different stages of fabrication was carried out to find shrinkage. Sintered density and interconnected porosity were measured using Archimedes’ principle. The characterization of the fabricated specimens was done with the help of microstructure analysis, scanning electron microscopy and energy dispersive x-ray analysis. Mechanical properties were assessed using compressive, tensile and Charpy tests.

Findings
The feasibility has been explored successfully to fabricate OCPRIMS of phosphor bronze using 3 DP and pressureless sintering process. Interconnected porosity of 51.45, 56.45, 64.09 per cent of final metallic specimens has been observed against the targeted 27, 30 and 40 per cent. The increase in pore dimensions up to 19.13 per cent and shrinkage up to 5.44 per cent of outer dimensions were found to be the main causes of increase in interconnected porosity level. The characterization results exhibit the behavior of pressureless sintering process and stability of the fabricated specimens. Mechanical properties of fabricated structures are found to be dependent on porosity and strut diameter. Compressive and tensile strength decrease with the increase in porosity for strut diameter less than 1 mm, whereas they increase with the increase in strut diameter of 1 mm or more. A similar trend has been observed for impact strength also.

Originality/value
This paper explores the feasibility to fabricate OCPRIMS economically using 3 DP and pressureless sintering process.
Thermal and surface characterization of ABS replicas made by FDM for rapid tooling applications
Authors: Chohan Jasgurpreet Singh , Singh Rupinder , Boparai Kamaljit Singh 
Published: November 2017

Purpose
This paper aims to focus on the changes in thermal and surface characteristics of acrylonitrile butadiene styrene (ABS) material when exposed to chemical vapours for surface finishing. The poor surface finish and the dimensional accuracy of the fused deposition modelling parts (of ABS material) because of the stair-stepping hinder their use for rapid tooling applications, which can be improved by vapour finishing process. The differential scanning calorimetry (DSC) tests are performed to investigate the thermal behaviour of ABS thermoplastic after vapour finishing.

Design/methodology/approach
The hip prosthesis replica has been used to highlight the efficacy of chemical finishing process for intricate and complex geometries. The replicas are treated with chemical vapours for different durations. The DSC tests are performed along with surface roughness, surface hardness and dimensional measurements of exposed replicas and compared with unexposed replica.

Findings
The longer finishing time, i.e. 20 s, manifested higher melting peak temperature, higher melting enthalpy and higher heat capacity along with smoother and harder surface as compared with unexposed replica. The finishing process enhanced the bonding strength and the heat-bearing capacity of ABS material. The vapour finishing process enhanced the thermal stability of the material which may extend its sustainability at higher temperatures.

Practical implications
The improved thermal stability of ABS thermoplastic after chemical vapour finishing has been demonstrated. This advancement allows the use of ABS in functional tooling suitable for small production runs with higher flexibility and lead time savings.

Originality/value
The heat effects associated with phase transitions as a function of temperature are studied in case of replicas finished with chemical vapours. The relationship between melting enthalpy and surface characteristics has been ascertained.
Selective laser melting using holographic beam manipulation: influence of polypropylene molecular weight
Authors: Haworth Barry , Tyrer John R. , Zhou Zhou 
Published: November 2017

Purpose
There is a requirement to match selective laser melting (SLM) technologies to a wider range of polymeric materials, as the existing market for SLM powders is dominated by polyamide PA12. Drivers include the tailoring of physical properties to individual applications or cost reduction. Polypropylene (PP) currently has limited use in SLM; so, this paper aims to explore the potential use of PP materials of varying molecular weight (Mw).

Design/methodology/approach
PP polymers of differing Mw were characterised using a range of analytical techniques, including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), rotational rheometry and real-time hot-stage (optical) microscopy.

Findings
The techniques are sufficiently sensitive to distinguish Mw effects, notably in terms of material viscosity. The stable sintering region for SLM has been defined clearly. Some success was achieved in melting parts using all grades of PP, including higher Mw grades, which potentially offer improved mechanical performance.

Research limitations/implications
The range of techniques (DSC, oxidative induction time and TGA) form an effective analytical package with which to consider new polymeric materials for SLM.

Practical implications
High-Mw PP polymers, in tape or powder form, have potential use in SLM processes, providing scope to enhance part properties in future.

Originality/value
This is believed to be the first in-depth study noting the influence of PP Mw on important physical performance in a proprietary SLM process, using holographic beam manipulation.
Additive manufacturing of ZrO2ceramic dental bridges by stereolithography
Authors: Lian Qin , Sui Wenquan , Wu Xiangquan , Yang Fei , Yang Shaopeng 
Published: November 2017

PurposeThis paper aims to develop an additive manufacturing technique for complex zirconia ceramic dental bridges.Design/methodology/approachTo carry out this study, a dental bridge model was obtained by three-dimensional reverse engineering, and a light-curable zirconia ceramic suspension was formulated. Zirconia bridges were manufactured by stereolithography and then treated by vacuum freeze drying, vacuum infiltration and sintering. The optimal scanning speed was determined according to the shape precision comparison. Then, characteristics of the sintered ceramic parts were tested as size shrinkage, relative density, surface Vickers hardness, surface roughness and microstructure.FindingsThe method for preparation of light-curable zirconia suspension (40 volume per cent solid loading) with a viscosity value of 127 mPa·s was proposed. The optimal laser scanning speed for zirconia bridge fabrication was 1200 mm/s. A relative density of 98.58 per cent was achieved; the obtained surface Vickers hardness and surface roughness were 1,398 HV and 2.06 µm, respectively.Originality/valueThis paper provides a potential technical method for manufacturing complex zirconia dental bridges and other small complex-shaped ceramic components which are difficult to be made by other manufacturing techniques.
Clinical and ex vivo laboratory comparison of the self‐sealing properties and dimensional stability between the femtosecond laser and manual clear corneal incisions
Authors: Kojima Takashi , Takagi Mari , Ichikawa Kei , Horai Rie , Sakai Yukihiro , Tanaka Yoshiki , Tamaoki Akeno , Ichikawa Kazuo 
Published: November 2017

AbstractPurposeTo compare the self‐sealing features and dimensional stability between the femtosecond laser (FL) and manual knife corneal incision.MethodsFor the clinical study, 29 consecutive eyes from 29 patients and 28 eyes from 28 patients who underwent cataract surgery with FL corneal incision and manual knife incision, respectively, were enrolled. Immediately after cataract surgery, the self‐sealing features of the corneal incisions were evaluated. Scanning electron microscopy (SEM) images were obtained. For the experimental study, clear corneal incisions with a knife or FL with different energy settings (3, 6 and 9 μJ) were created in fresh porcine eyes, followed by a stress test. The incision width was measured before and after the stress test.ResultsIn the clinical study, the knife group had a higher self‐sealing score (0.60 ± 0.49 points) than the FL group (0.17 ± 0.38 points). In the experimental study, the deformation rate in the knife incision (5.04 ± 1.93) was significantly lower than that in the FL with any energy. The deformation rate in the 9 μJ (12.98 ± 2.76) was significantly higher than in the 3 μJ (8.54 ± 2.38) and 6 μJ (8.82 ± 2.85) FL energies. Scanning electron microscopy (SEM) images revealed that the corneal stromal surface of the knife incision was smoother than that of the FL. Higher energy FL showed more irregular surfaces.ConclusionHigher FL energy tended to widen a clear corneal incision when mechanical stress was applied. The histological differences at the inner tunnel surface may cause differences in wound stability of the corneal incision.
Cyclic analogues of α‐conotoxin Vc1.1 inhibit colonic nociceptors and provide analgesia in a mouse model of chronic abdominal pain
Authors: Castro Joel , Grundy Luke , Deiteren Annemie , Harrington Andrea M , O'Donnell Tracey , Maddern Jessica , Moore Jessi , Garcia‐Caraballo Sonia , Rychkov Grigori Y , Yu Rilei , Kaas Quentin , Craik David J , Adams David J , Brierley Stuart M 
Published: November 2017

Background and PurposePatients with irritable bowel syndrome suffer from chronic visceral pain (CVP) and limited analgesic therapeutic options are currently available. We have shown that α‐conotoxin Vc1.1 induced activation of GABAB receptors on the peripheral endings of colonic afferents and reduced nociceptive signalling from the viscera. However, the analgesic efficacy of more stable, cyclized versions of Vc1.1 on CVP remains to be determined.Experimental ApproachUsing ex vivo colonic afferent preparations from mice, we determined the inhibitory actions of cyclized Vc1.1 (cVc1.1) and two cVc1.1 analogues on mouse colonic nociceptors in healthy and chronic visceral hypersensitivity (CVH) states. Using whole‐cell patch clamp recordings, we also assessed the inhibitory actions of these peptides on the neuronal excitability of colonic innervating dorsal root ganglion neurons. In vivo, the analgesic efficacy of these analogues was assessed by determining the visceromotor response to colorectal distension in healthy and CVH mice.Key ResultscVc1.1 and the cVc1.1 analogues, [C2H,C8F]cVc1.1 and [N9W]cVc1.1, all caused concentration‐dependent inhibition of colonic nociceptors from healthy mice. Inhibition by these peptides was greater than those evoked by linear Vc1.1 and was substantially greater in colonic nociceptors from CVH mice. cVc1.1 also reduced excitability of colonic dorsal root ganglion neurons, with greater effect in CVH neurons. CVH mice treated with cVc1.1 intra‐colonically displayed reduced pain responses to noxious colorectal distension compared with vehicle‐treated CVH mice.Conclusions and ImplicationsCyclic versions of Vc1.1 evoked significant anti‐nociceptive actions in CVH states, suggesting that they could be novel candidates for treatment of CVP.Linked ArticlesThis article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc
Role of anterior segment optical coherence tomography in angle‐closure disease: a review
Authors: Porporato Natalia , Baskaran Mani , Aung Tin 
Published: November 2017

AbstractThis article aims to review the published literature pertaining to the use of anterior segment optical coherence tomography (AS‐OCT) in the evaluation of angle‐closure disease. Searches on the available published literature were last conducted on 15 June 2017. Rated as Level I evidence, we found that AS‐OCT has shown good sensitivity and moderate diagnostic accuracy to detect narrow angles when compared with gonioscopy. AS‐OCT quantitative and qualitative parameters demonstrated strong association with the presence of gonioscopically closed angles. This technology provides an objective non‐contact method of assessing the angle that is well tolerated by the patient and correlates well with the information provided by gonioscopy.
Italy in the Renaissance: a leading economy in the European context, 1350–1550
Authors: Malanima Paolo 
Published: November 2017

AbstractA well‐known debate on the Renaissance economy was held in this journal in 1962–4 between Roberto S. Lopez and Harry Miskimin on one hand and Carlo M. Cipolla on the other. More than half a century later, this topic can be reconsidered in the light of much wider information on the late medieval/early modern Italian economy. Using data on population, urbanization, prices, wages, and GDP, this article outlines the macroeconomic trends in central and northern Italy in the age of the Renaissance (1350–1550). The frequent plagues during the early Renaissance—that is, between 1348 and 1450—decimated the population, probably causing more deaths than in other European countries. Hence resources per worker increased and labour productivity, incomes, and standards of living improved remarkably. A favourable economic environment thus seems to have been a pre‐condition for the Renaissance in culture, art, and politics and the spread of new kinds of consumer demand. From the middle of the fifteenth century, living standards gradually worsened and eventually reached the low levels that had prevailed prior to the Renaissance.
Lower mean blood glucose during short‐term intensive insulin therapy is associated with long‐term glycemic remission in patients with newly diagnosed type 2 diabetes: Evidence‐based recommendations for standardization
Authors: Liu Liehua , Liu Juan , Xu Lijuan , Ke Weijian , Wan Xuesi , Li Hai , He Xiaoying , Wang Liangjiao , Cao Xiaopei , Xiao Haipeng , Li Yanbing 
Published: November 2017

AbstractAims/IntroductionOptimal glycemic targets during short‐term intensive insulin therapy in patients with newly diagnosed type 2 diabetes are not standardized. The present study was carried out to determine the optimal glycemic targets during therapy by analyzing the impacts of glucose levels on therapeutic outcomes.Materials and MethodsA total of 95 individuals with newly diagnosed type 2 diabetes were enrolled. Short‐term intensive insulin therapy was carried out using an insulin pump to achieve and maintain glycemic targets (fasting blood glucose ≤6.0 mmol/L, 2‐h postprandial blood glucose ≤7.8 mmol/L) for 14 days, with daily eight‐point capillary blood glucose profiles recorded. Patients were followed up for 1 year after discharge.ResultsIn most participants, the mean blood glucose and glycemic excursion parameters during the therapy were controlled within the normal range. Mean blood glucose was independently associated with amelioration of acute insulin response (r = −0.25, P = 0.015) and 1‐year remission (odds ratio 0.12, 95% confidence interval 0.034–0.426), but negatively associated with more level 1 hypoglycemia (r = −0.34, P = 0.001), although major hypoglycemia was rare. Among mean blood glucose tertiles, patients in the middle (68.7%) and lower (75.0%) tertiles had a higher 1‐year remission rate compared with the upper tertile (32.3%, both P < 0.001), whereas only the middle tertile did not have increased hypoglycemia compared with the upper tertile (8.1 ± 5.4 vs 7.2 ± 3.9 events/person, P = 0.48).ConclusionsStricter glycemic control during short‐term intensive insulin therapy produced more remission despite self‐manageable hypoglycemia. Based on glycemic parameters in the middle mean tertile, we propose new glycemic targets that are approximately 0.4 mmol/L lower than current the targets, as long‐term benefit outweighs short‐term risks.
Treatment of pathologic peri‐implant pockets
Authors: Renvert Stefan , Polyzois Ioannis 
Published: November 2017

AbstractPeri‐implant and periodontal pockets share a number of anatomical features but also have distinct differences. These differences make peri‐implant pockets more susceptible to trauma and infection than periodontal pockets. Inadequate maintenance can lead to infections (defined as peri‐implant mucositis and peri‐implantitis) within peri‐implant pockets. These infections are recognized as inflammatory diseases, which ultimately lead to the loss of supporting bone. Diagnostic and treatment methods conventionally used in periodontics have been adopted to assess and treat these diseases. Controlling infection includes elimination of the biofilm from the implant surface and efficient mechanical debridement. However, the prosthetic supra‐structure and implant surface characteristics can complicate treatment. Evidence shows that when appropriately managed, peri‐implant mucositis is reversible. Nonsurgical therapy, with or without the use of antimicrobials, will occasionally resolve peri‐implantitis, but for the majority of advanced lesions this approach is insufficient and surgery is indicated. The major objective of the surgical approach is to provide access and visualize the clinical situation. Hence, a more informed decision can be made regarding whether to use a resective or a regenerative surgical technique. Evidence shows that following successful decontamination, surgical treatment to regenerate the bone can be performed, and a number of regenerative techniques have been proposed. After treatment, regular maintenance and good oral hygiene are essential for a predictable outcome and long‐term stability.
Engine Performances With Advanced Common Rail Injector Design
Authors: Zimmermann Kilian , Haefeli Richard , Ganser Marco 
Published: November 2017

This paper presents the application of the Ganser CRS common rail injectors with the proprietary poppet valve, the state of the art hydraulic switching device for common rail injectors. Due to its unique design, the combustion process is optimized by stable and rapid injection rate profiles, which are allowing for reliable multiple injection driving strategies to further reduce the fuel consumption and in-cylinder emissions. Due to its flexible characteristics, the poppet valve is applicable in numerous fields. Two applications are specifically presented in this paper.
The first application of the poppet valve is the common rail retrofit of a V16 GE® 7FDL locomotive engine with a power output of 4000HP. In this retrofit project, the existing mechanical fuel injection system is replaced by a common rail system. The injector design is such that no changes to the cylinder head are required. The injector includes an integrated accumulator for maximized and constant injection pressures during the whole injection process. Each cylinder bank is equipped with its own slim rail attached to the engine structure and a dedicated high pressure pump, allowing for a freely configurable injection event up to 1600bar. The resulting significant reduction of fuel consumption over the locomotive duty cycle as well as emissions reductions are discussed in detail in this paper.
The poppet valve is also successfully applied in the field of micro pilot injection for new dual fuel engines, in the marine and power-gen sectors, as a second application of this injector design principle. On these engines, the micro pilot injection quantity to ignite the gas is typically 0.5–2% of the total energy input. This maximized diesel fuel substitution is possible because of the accurate switching characteristics of the poppet valve at smallest injection quantities. With the application of the proprietary Wave Dynamics and Dampening System (WDD) [1] and injector-integrated accumulators, the rail can be replaced completely by so-called jumper lines, while maintaining a slim outer shape on the overall injector size.
CFD Simulations of the Effect of Water Injection Characteristics on TSCI: A New, Load-Flexible, Advanced Combustion Concept
Authors: Rahimi Boldaji Mozhgan , Sofianopoulos Aimilios , Mamalis Sotirios , Lawler Benjamin 
Published: November 2017

Homogeneous Charge Compression Ignition (HCCI) combustion has the potential for high efficiency with very low levels of NOx and soot emissions. However, HCCI has thus far only been achievable in a laboratory setting due to the following challenges: 1) there is a lack of control over the start and rate of combustion, and 2) there is a very limited and narrow operating range. In the present work, the injection of water directly into the combustion chamber was investigated to solve the aforementioned limitations of HCCI. This new advanced combustion mode is called Thermally Stratified Compression Ignition (TSCI).
A 3-D CFD model was developed using CONVERGE CFD coupled with detailed chemical kinetics to gain a better understanding of the underlying phenomena of the water injection event in a homogeneous, low temperature combustion strategy. The CFD model was first validated against previously collected experimental data. The model was then used to simulate TSCI combustion and the results indicate that injecting water into the combustion chamber decreases the overall unburned gas temperature and increases the level of thermal stratification prior to ignition. The increased thermal stratification results in a decreased rate of combustion, thereby providing control over its rate. The results show that the peak pressure and gross heat release rate decrease by 37.8% and 83.2%, respectively, when 6.7 mg of water were injected per cycle at a pressure of 160 bar. Finally, different spray patterns were simulated to observe their effect on the level of thermal stratification prior to ignition. The results show that symmetric patterns with more nozzle holes were generally more effective at increasing thermal stratification.