A bibliometric analysis of global laparoscopy research trends during 1997–2011

In this study, we aim to evaluate the global scientific output of laparoscopy research, and try to find an alternative statistical approach to quantitatively and qualitatively assess the current global research trend on laparoscopy. Data were based on the Science Citation Index Expanded (SCI-E), from the Institute of Scientific Information Web of Science database. Articles referring to laparoscopy during 1997–2011 were concentrated on the analysis by scientific output characters, international collaboration, and the frequency of author keywords used. Globally, 59,264 papers were published during the 15-year study period, including 15 document types. Among them, there were 40,318 articles, to which a two-phase model was applied to simulate the high correlation between cumulative number of articles and the year. International collaborative publications were more prevalent in recent years, and were more powerful due to the sharing of ideas and workloads. Japan, Sweden, Poland, Canada, the UK, India, France and Spain benefit a lot from the international cooperation. With the comprehensive analysis of distribution and change of article titles, author keywords and abstracts, it can be concluded that research related to ‘morbid obesity’, ‘robotic surgery’, ‘prostatectomy’ and ‘NOTES (natural orifice transluminal endoscopic surgery)’ are the main orientations of all the laparoscopy research in the 21st century.     

Common cause failure analysis of cyber–physical systems situated in constructed environments

While cyber–physical system sciences are developing methods for studying reliability that span domains such as mechanics, electronics and control, there remains a lack of methods for investigating the impact of the environment on the system. External conditions such as flooding, fire or toxic gas may damage equipment and failing to foresee such possibilities will result in invalid worst-case estimates of the safety and reliability of the system. Even if single component failures are anticipated, abnormal environmental conditions may result in common cause failures that cripple the system. This paper proposes a framework for modeling interactions between a cyber–physical system and its environment. The framework is limited to environments consisting of spaces with clear physical boundaries, such as power plants, buildings, mines and urban underground infrastructures. The purpose of the framework is to support simulation-based risk analysis of an initiating event such as an equipment failure or flooding. The functional failure identification and propagation (FFIP) framework is extended for this purpose, so that the simulation is able to detect component failures arising from abnormal environmental conditions and vice versa: Flooding could be caused by a failure in a pipe or valve component. As abnormal flow states propagate through the system and its environment, the goal of the simulation is to identify the system-wide cumulative effect of the initiating event and any related common cause failure scenario. FFIP determines this effect in terms of degradation or loss of the functionality of the system. The method is demonstrated with a nuclear reactor’s redundant coolant supply system.     

Monitoring and control of coating and granulation processes in fluidized beds – A review

This review presents a compilation of works of the main techniques for monitoring and control fluidization regimes, particle size and moisture content during coating and granulation processes in the fluidized bed. The development of monitoring and control systems for coating and granulation of particles is highly desirable, not only to allow the operation in a stable bubbling fluidization regime, which intensifies heat and mass transfer, but also to ensure strict quality specifications for products, such as, uniform particle size distribution, low moisture content and good flowability. This paper focuses on the discussion of methods used and results obtained in studies on monitoring and control of granulation and coating process in the fluidized bed reported in the literature in the last decades. Pressure fluctuation signal analysis is widely discussed as a tool of regime monitoring. To monitor particle size, techniques such as, Near Infrared spectroscopy (NIR), Focused Beam Reflectance Measurements (FBRMs), among others are presented in detail. As for moisture content tracking, the methods are reviewed like acoustic signals, capacitance, microwave resonance and spectroscopy. It is evident that although these processes are highly complex, the techniques presented here have evolved mainly due to the efforts of several research groups, showing great potential for applications in industry, emphasizing the importance of this research field.     

Reliability in composites – A selective review and survey of current development

As a response to the rampant increase in research activity within reliability in the past few decades, and to the lack of a conclusive framework for composite applications, this article attempts to identify the most relevant reliability topics to composite materials and provide a selective review. Available reliability assessment methods are briefly explained, referenced and compared within an unified formulation. Recent developments to confer efficiency in computing reliability in large composite structures are also highlighted. Finally, some general conclusions are derived along with an overview of future directions of research within reliability of composite materials and their influence on design and optimization.     

The behaviour of commercial FeCrAlRE alloys in nitrogen-oxygen – water vapour bioxidant environments

Abstract

The corrosion behaviour of a range of commercial FeCrAlRE alloys (MA956, ODM751, PM2000, Kanthal AF, Kanthal APM and Aluchrom YHf) have been examined in nitrogen–oxygen-H₂O or N₂–H₂–H₂O bioxidant environments, at temperatures between 1100°C and 1350°C. The corrosion behaviour is governed by the competition between oxidation leading to protective alumina formation/ maintenance and nitrogen ingress leading to nitridation of the matrix alloy. Key issues addressed by four series of experiments, have included: the influence of a pre-formed protective alumina scale; the oxidant level required to form/reheal a protective oxide scale; the role of mechanical failure of the scale above the critical thickness for cracking/spallation in oxygen rich environments; chemical failure of the protective oxide scale leading to breakaway (non-protective) attack and in particular, the potential roles in such failure processes of nitridation concurrent with, and following defective oxide scale formation, and of oxidation following nitridation.

Detailed characterisation of the chemical composition and physical microstructure of the attack of the respective alloys was undertaken using a range of surface analytical techniques, including X-ray diffraction, optical and scanning electron microscopy and energy dispersive X-ray analysis.     

Sadhana – Academy Proceedings in Engineering Sciences: A scientometric analysis

This study presents a scientometric analysis of 253 articles published in Sadhana during the year 2005–2009. Five volumes of the journal are taken up to observe the distribution of contribution, authorship pattern, institution-wise distribution, geographical distribution of contribution, average length of paper, tables and illustrations used and citation pattern in each volume. Results indicate that highest number of papers have been written by two authors. The contributions received in this journal are more from India than from the other countries. Foreign documents show their more representation in references cited. Journals are referred more frequently than other documents.The average number of references per article is 23.72 and 200.602 per volume.     

Casting defects induced fatigue damage in aircraft frames of ZL205A aluminum alloy – A failure analysis

Two different types of aircraft frame components, which had collapsed respectively in their former vibration-fatigue performance tests, were submitted for failure analysis. The two failed frames were both made of aerial material ZL205A, a high-strength cast Al–Cu–Mn–Ti alloy. According to a series of experimental procedures including visual observations, X-ray detections, fractography inspections, microstructure examinations, mechanical tensile tests, hardness measurements and fluorescent penetrating inspections, it was indicated that the fracture was attributed to fatigue cracks which were induced by casting porosity defects at the external surfaces of frames. Numerous fine fatigue striations presented in the vicinity of casting porosities. Especially, it was observed of a special appearance of latitude–longitude crossed fatigue striations on the fracture surface due to the coupled stresses supplied by the former multi-directional vibration tests. The overload fast-rupture regions on fracture surfaces suggested the typical cleavage fracture mode, which was characterized by a number of river patterns and cleavage steps. The intergranular spatial dendrite-shaped casting porosities largely contributed to the local stress-concentrations in matrix materials. Triangular grain boundaries induced by the former casting burnt implied that the intergranular melting phenomenon had occurred. Furthermore, the effect of groove-shaped structure at roots of spatial convex-bodies on the edge of casting porosity was especially analyzed. And the influence of the casting porosity size on fatigue cracks was briefly discussed.     

Structure and evolution of innovation research in the last 60 years: review and future trends in the field of business through the citations and co-citations analysis

The field of innovation studies has grown considerably in the last four decades, which has led to the emergence of new approaches and theoretical aspects that need to be examined and considered. Therefore, this paper aims to understand what are the main theoretical pillars that support the structure of innovation theories and fields, how it evolved over the years and what are the directions that lead to future trends in innovation research. The procedure consists in a mix-methods using the citation and co-citation analysis associated with bibliometric methods, Social Network Analysis, and a systematic review of the literature. The results were validated by Delphi with academic specialists in innovation. Considering publications between 1956 and 2016 divided into four 15-years timespan, the longitudinal analysis results indicate the evolution of the main streams of thoughts that support the current innovation research fields and depict a research orientation for future works that can be developed to generate relevant contributions for the theoretical development of the area. This paper differentiates itself bringing results based on a large database, by the research methods employed, and by the perspective adopted provides solid contributions to the understanding of the past, present, and future of the scientific research in innovation to business administration field.     

A near-infrared study of hydrogen bonds in alcohols—comparison of chemometrics and spectroscopic analysis

Near-infrared (NIR) spectra of n-, sec-, and tert-butanol in CCl₄ were measured over a temperature range of 10–60°C. The spectra obtained were analyzed by both spectroscopic analytical methods such as calculations of the difference spectra and the second derivatives, and chemometrics, namely partial least squares (PLS) regression. The present study aims at comparing the spectroscopic analytical methods with chemometrics in the analysis of NIR spectra of n-, sec-, and tert-butanols in CCl₄. The three kinds of alcohol showed an intense band due to the first overtone of the OH stretching mode in the 7120–7030 cm⁻¹ (1404–1422 nm) region. The calculations of the difference spectra and the second derivatives revealed that the above bands of n- and sec-butanol consist of three and four component bands, respectively, due to the rotational isomerism of the monomer, the OH group weakly hydrogen-bonded with CCl₄, and the terminal free OH groups of the self-associated species. For tert-butanol, which does not have the rotational isomerism, the corresponding band splits into only two components. Temperature of the alcohols was predicted by use of PLS regression. The regression coefficients for the models predicting the temperature of the alcohols were almost identical with the difference spectra of the alcohols between 10 and 60°C. Both the regression coefficients and the difference spectra reflect strongly the changes in the hydrogen bonds of the alcohols.     

Influence of plastic deformation in flexible pad laser shock forming – experimental and numerical analysis

Flexible Pad Laser Shock Forming (FPLSF) is a new microforming process using laser-induced shock pressure and a hyperelastic flexible pad to induce high strain-rate (~10⁵ s^?1) plastic deformation on metallic foils to produce 3D microcraters. This paper studies the effect of two significant process parameters of FPLSF, flexible pad material and its thickness, on the deformation characteristics of the metal foils using experiments and finite element analysis. A finite element model is developed to simulate the FPLSF process. The stress-strain distribution across the foil and the flexible pad at different process stages of FPLSF are studied using FE analysis. Flexible pad materials including silicone rubber, polyurethane rubber, and natural rubber with thicknesses ranging between 300 μm and 3000 μm have been investigated in detail. Experimental results highlight that both the hardness and thickness of the flexible pad significantly influence the deformed crater geometry, thickness distribution across the formed crater and surface hardness at the crater surfaces. The experimental results are correlated with the stress-strain distributions from finite element analysis to study the underlying behaviors.     

Assessment of patentability by means of semantic patent analysis – A mathematical-logical approach

To obtain patent protection, a patent must fulfill statutory patentability requirements examined by a patent office. Such examinations are mostly performed manually and are quite time-consuming. Therefore, we suggest a computer-based process for the assessment of patentability by means of a mathematical-logical approach comparing patents with semantic structures. In order to make such an assessment, we compare the feature combinations of patent claims with the pertinent prior art. For proof of concept, the process has been tested successfully on an US-application claiming a method for raising a crane boom which can be categorized as non-patentable with regard to the requirement of non-obviousness. The result is consistent with that of a USPTO patent examiner, which underpins that at least under certain conditions not only patent examiners but also applicants and third parties can assess the chance and scope of protection for claimed inventions and patent applications with regard to patentability by our process.     

Erosion–corrosion of preoxidised Incoloy 800H in fluidised bed environments: effects of temperature,velocity, and exposure time

Abstract

The effects of preoxidation as a potential protective measure for alloys exposed to erosion–corrosion have been evaluated for Incoloy 800H in laboratory simulated fluidised bed conditions. The performance of the specimens after exposure to such environments was estimated from weight change data, electron microscopy, and X-ray diffraction patterns. The results showed that, in ‘corrosion dominated’ conditions, i.e. at relatively high temperatures and low velocities, preoxidation was successful in reducing the erosion–corrosion of the underlying alloy. However, when the velocity was increased and the temperature decreased, preoxidation afforded only some short term protection to the alloy. In these more ‘erosion–corrosion dominated’ regimes, preoxidation delayed the incubation period for erosion–corrosion of the alloy, but, once the scale was removed, the erosion–corrosion rates were similar to those of the non-preoxidised alloys. The effects of temperature, velocity, and exposure time are discussed for the preoxidised and non-preoxidised alloys. Comparisons are made between the results of the present and other erosion–corrosion studies, to explain the distinctive pattern of alloy wastage in these environments.

MST/1432     

Fatigue crack propagation in nickel-base superalloys – effects of microstructure,load ratio,and temperature

Abstract

The current state of knowledge and understanding of the long fatigue crack propagation behaviour of nickel-base superalloys are reviewed, with particular emphasis on turbine disc materials. The data are presented in the form of crack growth rate da/dN versus stress intensity factor range δK curves, and the effects of such variables as microstructure, load ratio R, and temperature in the near-threshold and Paris regimes of the curves, are discussed.

MST/521     

Diffractive,refractive optics or anything more? Comparative analysis and trends of development

Abstract

The development of diffractive and refractive optics from ancient times (2000 years ago) to the present is traced from a theoretical and practical point of view. A comparative analysis of the possibilities of the two fields in optics is presented. The possibility for achromatization and corrections that exceed the boundary of diffractive and refractive optical elements is pointed out.     

Cytotoxic and apoptotic effects of cobalt and chromium ions on J774 macrophages – Implication of caspase-3 in the apoptotic pathway

The aim of this study was to evaluate the cytotoxic and apoptotic effects of cobalt and chromium ions on macrophages in vitro, and analyze the implication of caspase-3 in the apoptotic pathway. J774 mouse macrophages (5 x 10(5) cells/ml) were exposed for up to 24 h to 0-10 ppm Co2+ and 0-500 ppm Cr3+. The cytotoxic effect of ions was measured by Trypan blue exclusion. DNA analysis on agarose gel was used as a specific test for detection of DNA fragmentation into oligonucleosomes that occurs in apoptotic cells. The proteolytic cleavage of poly(ADP-ribose)polymerase (PARP), closely associated with the induction of apoptosis, was also analyzed along with the appearance of the active fragment of caspase-3, implicated in several apoptosis pathways. Results demonstrated that both Co2+ and Cr3+ ions induce macrophage mortality in a dose-dependent manner. However, Co2+ is more toxic inducing a cell mortality up to 28% with only 10 ppm vs. 37% with 500 ppm of Cr3+. DNA analysis demonstrated that both Co2+ and Cr3+ ions induce DNA fragmentation, between 6-10 ppm Co2+ and 250-500 ppm Cr3+ after 24 h incubation. PARP cleavage and the appearance of caspase-3 active fragment were observed after 6 h with both Co+ and Cr3+ ions, with a stronger signal after 24 h and 10 ppm of Co2+ or 500 ppm of Cr3+. In conclusion, this study demonstrates that after 24 h incubation, both Co2+ and Cr3+ ions can induce macrophage mortality, and more specifically apoptosis. The results also suggest that apoptosis occurs via a caspase-3 pathway. However, the relative importance of necrosis and apoptosis and the effects of longer exposure times on the induction of macrophage death by these metal ions remain to be investigated.     

Creating resilient and sustainable manufacturing businesses – a conceptual fitness model

Over recent years, UK manufacturing industry has experienced turbulence in its business performance. Lower cost products, and responsive and flexible processes, are now essential in order for a company to capture new markets and to become economically resilient. Business resiliency is a term used frequently to describe a company’s ability to adapt and cope with disturbance. This has led to the generation of many frameworks and models aimed at guiding companies towards improved business performance. However, these frameworks are primarily strategic in nature and do not necessarily focus on creating resilience at an operational level in manufacturing companies. The authors employ a mixed research approach initially undertaking a literature review and then a screening survey in to 25 manufacturing companies in order to identify the key business resiliency techniques employed. Following this, a focus group goes on to detail a new manufacturing resiliency model called the fit operational model. The model’s effectiveness is then assessed and adjusted as a result of being implemented in a subject company.     

Characterizing the intrinsic properties of powder – A combined discrete element analysis and Hall flowmeter testing study

Discrete element modelling (DEM) and experimental characterization were carried out for Hall flowmeter tests, in which Inconel718 powders were poured down through a funnel into a density cup to form a heap. By measuring the flow rate, angle of repose and packing fraction from the experiments, and combining with DEM simulations, we were able to extract the coefficients of friction for the powder-powder and powder-wall interactions. We further studied the effect of powder-powder adhesion and found that the adhesion could greatly affect the flow rate and flow pattern. In particular, by increasing the adhesion, we observed a transition from a continuous to discontinuous discharging flow, and revealed an underlying mechanism for the transition. We also studied the effects of powder size and density cup diameter, and found that at their application size scale, the influences of these parameters on the measured results are negligible. The present work presents a simple approach to study the intrinsic properties of powders, and their influences on flowability and packing property.     

Visual analysis of solidification and δ–γ transformations in steels

Abstract

The theory of solidification of steels and the kinetics of austenite to α-ferrite phase transformation were extensively studied; however, comparatively, little information is available concerning the kinetics of the δ-ferrite to austenite transformation due to the difficulty of making in situ observations. In the present study, a laser scanning confocal microscopy with an infrared image furnace was implemented with which the in situ observations at the high temperature of the dynamic behaviour of the δ/γ grain nucleation and growth and interphase boundaries of the steels are made possible. The solidification mode of the carbon steel and the austenitic stainless steel during welding can be directly observed, and the definitive sequence of phase transformation that led to the final microstructure was detected in real time. Finally, new experimental results will be presented and compared with previous studies.