Prediction of hydrodynamics and chemistry of confined turbulent methane-air frames in a two concentric tube combustor

A formulation of the governing partial differential equations for fluid flow and reacting chemical species in a two-concentric-tube combustor is presented. A numerical procedure for the solution of the governing differential equations is described and models for chemical-equilibrium and chemical-kinetics calculations are presented. The chemical-equilibrium model is used to characterize the hydrocarbon reactions. The chemical-kinetics model is used to predict the concentrations of the oxides of nitrogen. The combustor considered consists of two coaxial ducts. Concentric streams of gaseous fuel and air enter the inlet duct at one end; the flow then reverses and flows out through the outer duct. Two sample cases with specified inlet and boundary conditions are considered and the results are discussed

Reliable Cost Prediction and Control for Intelligent Manufacture: A Key Performance Indicator Perspective

Data Availability Statement: Not applicable. Acknowledgments: We would like to thank Primal Electro for providing the industrial data.Intelligent manufacturing is facing significant challenges in adapting to the ever-changing equipment, instrumentation, process and economics. Such a trend together with the pressure to reliably control and contain production costs means that frequent adjusting decisions are required to adapt to incessant volatility imposed on manufacturing systems. Under this circumstance, cost-effective and quality-guaranteed manufacturing strategies would be the most logical route to reducing production costs. In this paper, a novel dynamical cost prediction and control (CPC) model is proposed to support collective decision-making in intelligent manufacturing, where the model output is the real-time prediction of possible manufacturing costs, while the inputs are generic manufacturing key performance indicators covering inventory, product quality, production efficiency, resource utilisation and environmental impact. This proposed CPC model distinguishes itself from existing ones for its capability to translate manufacturing data (at both the physical level and operation management level) into financial metrics that contribute to forming a common language between engineering, financial and administrative departments of an enterprise. The case study about the assembly line of optoelectronic devices demonstrates that, although different enterprise departments have different priorities, our CPC model helps them to achieve certain consensus on intended production that finally creates satisfactory profitability for the company at controlled manufacturing costs.Natural Science Foundation of Sichuan Province of China under Grant 23NSFSC1427; National Natural Science Foundation of China under Grants U2330206, U2230206, 62173068l European Union’s Horizon 2020 Research and Innovation Programme under Grant 820677 (IQONIC)

The clinical relevance of PCL index on the reconstruction of anterior cruciate ligament with hamstring tendon autograft

The posterior cruciate ligament index (PCL index) has been reported as a diagnostic and prognostic marker for anterior cruciate ligament (ACL) reconstruction. The clinical relevance of PCL index on the reconstruction of ACL with hamstring tendon autograft has not been described in the literature. The objective of this study is to evaluate the importance of the PCL index as a marker of anatomic reconstruction and of functional improvement of patients undergoing ACL reconstruction with HT autograft. Twenty-four patients were submitted to ACL reconstruction with HT autograft. The PCL index was assessed by magnetic resonance imaging before and after surgery. The functional evaluation was performed through the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form© and Knee Society Knee Scoring System© (IKS). Patients presented a significant positive variation of the PCL index, IKDC and IKS scores. There is no significant correlation between PCL index variation and IKDC and IKS scores (p > 0.05). Unlike other studies reporting a relationship between the PCL index, control of rotational kinematics, and functional improvement in patients undergoing ACL reconstruction with bone-patellar tendon-bone autograft, this study does not demonstrate this association. There is evidence in this study to show that the PCL index may be used as an anatomic reconstructive marker of ACL but not to predict the clinical outcome in this type of reconstruction.(undefined

A new design for friction stir spot joining of Al alloys and carbon fibre reinforced composites

Friction stir spot welding (FSSW) has been recently developed to join dissimilar materials. However, the traditional requirement for a rotating tool consists of a pin and shoulder in FSSW leads to a complex joining process and unpredictable defects. In this study, a new static-shoulder design in FSSW was proposed and developed to join Al alloys to carbon fiber-reinforced polymer (CFRP) composites. The main joining parameters, including pin rotational speed, pin feed rate and pin plunge depth, were varied to investigate their effects on the joining temperature, materials interaction and the strength of joints. The pin rotational speed had the largest influence on the joining temperature. Lap shear tensile testing was conducted to evaluate the performance of the joints. The joints exhibited the ultimate lap shear force from 230 to 260 N. A brittle fracture occurred with the displacement-at-fracture load of 0.35-0.41 mm. Cross-sectional images revealed the creation of undulations on the surface of Al alloys in the joining zone. The undulations created a macro-mechanical interlocking bonding between the materials, which determined the performance of the joints. For a flat pin, by increasing the plunge depth from 1.25 to 1.30 mm, the undulation size increased from 0.21 to 0.26 mm, which can enhance the macro-mechanical interlocking bonding between Al alloys and CFRP and accordingly increased the ultimate shear force of the joints from 230 to 241 N. Use of a fluted pin significantly influenced the flow of the plasticized Al alloy which created pronounced undulations and large Al alloy spikes of 0.46 mm. These features seemed to establish an efficient macro-mechanical interlocking bonding, which resulted in a noticeable improvement in the performance of the joint. For a plunge depth of 1.30 mm, the ultimate shear force increased to 261 N using the fluted pin

Alexandros Zaoussis, MD, PhD (1923-2005): An orthopedic surgeon and historian and his contribution to the establishment of hip surgery

The purpose of our study was to summarize all the knowledge concerning the innovative pioneer in the field of orthopedic surgery and especially hip replacement, Alexandros Zaoussis (1923-2005). He was a pioneer in hip replacement, and he contributed to several fields of orthopedic surgery with his clinical work and his international publications. He was also an eminent historian of World War II and of the Greek Resistance to the Nazi occupation in which he played a significant part. A thorough study of texts, medical books, and reports in the field of history of medicine, together with a review of the available literature in PubMed, was undertaken. He was an eminent clinical director of orthopedics who had significant contribution in teaching, practicing, and expanding the horizons of orthopedic surgery in the 20th century. A thorough review of medical texts, books, and publications in the Greek academic press was undertaken to summarize his contributions and his turbulent life to commemorate the 10th anniversary of his death. © The Author(s) 2016

Performance analysis of content matching intrusion detection systems

A central question in the design and evaluation of a Network Intrusion Detection System (nIDS) is whether it is possible to define a practical, accurate and meaningful performance evaluation methodology. In this direction, we examine how nIDS performance interacts with experiment parameters such as traffic characteristics, nIDS rulesets, string matching algorithms and processor architecture. Our results indicate that nIDS performance is sensitive to the both packet and ruleset content, yet this sensitivity seems to be bounded, allowing us to craft and experiment with synthetic traces and rulesets. Our experiments also show that experiments on a single trace and processor architecture are likely to be misleading; effective nIDS evaluation therefore requires careful consideration of a fairly extensive set of scenarios

A hydrometeorological, three-dimensional model of thermal energy releases into environmental media

A computer model has been developed to study thermal energy releases into the environment. A typical application of the model is the study of the behaviour of cooling-tower effluent under different weather and operating conditions. The model employs the full three-dimensional transport equations describing the conservation of mass, momentum and energy. The flow is treated as single-phase and the behaviour of any droplets present is calculated indirectly. The model takes into account such hydrometeorological phenomena as the effects of humidity, wind direction and speed, density variations and the presence and precipitation of droplets. Sample results from cooling tower applications are presented and discussed

A hydrometeorological, three-dimensional model of thermal energy releases into environmental media

A computer model has been developed to study thermal energy releases into the environment. A typical application of the model is the study of the behaviour of cooling-tower effluent under different weather and operating conditions. The model employs the full three-dimensional transport equations describing the conservation of mass, momentum and energy. The flow is treated as single-phase and the behaviour of any droplets present is calculated indirectly. The model takes into account such hydrometeorological phenomena as the effects of humidity, wind direction and speed, density variations and the presence and precipitation of droplets. Sample results from cooling tower applications are presented and discussed