Simulation aided development of pre-chamber ignition system for a lean-burn gasoline direct injection motor-sport engine

Due to recent regulation changes to restricted fuel usage in various motor-sport events, motor-sport engine manufacturers have started to focus on improving the thermal efficiency and often claim thermal efficiency figures well above equivalent road car engines. With limited fuel allowance, motorsport engines are operated with a lean air-fuel mixture to benefit from higher cycle efficiency, requiring an ignition system that is suitable for the lean mixture. Pre-chamber ignition is identified as a promising method to improve lean limit and has the potential to reduce end gas auto-ignition. This paper analyses the full-load performance of a motor-sport lean-burn GDI engine and a passive pre-chamber is developed with the aid of a CFD tool. The finalized pre-chamber design benefited in a significant reduction in burn duration, reduced cyclic variation, knock limit extension and higher performance

Influence of Different Abutment Designs on the Biomechanical Behavior of One-Piece Zirconia Dental Implants and Their Surrounding Bone: A 3D-FEA

Background: In a dental implant/bone system, the design factors affect the value and distributions of stress and deformations that plays a pivotal role on the stability, durability and lifespan of the implant/bone system

Protein phosphatase 5 regulates titin phosphorylation and function at a sarcomere-associated mechanosensor complex in cardiomyocytes.

Serine/threonine protein phosphatase 5 (PP5) is ubiquitously expressed in eukaryotic cells; however, its function in cardiomyocytes is unknown. Under basal conditions, PP5 is autoinhibited, but enzymatic activity rises upon binding of specific factors, such as the chaperone Hsp90. Here we show that PP5 binds and dephosphorylates the elastic N2B-unique sequence (N2Bus) of titin in cardiomyocytes. Using various binding and phosphorylation tests, cell-culture manipulation, and transgenic mouse hearts, we demonstrate that PP5 associates with N2Bus in vitro and in sarcomeres and is antagonistic to several protein kinases, which phosphorylate N2Bus and lower titin-based passive tension. PP5 is pathologically elevated and likely contributes to hypo-phosphorylation of N2Bus in failing human hearts. Furthermore, Hsp90-activated PP5 interacts with components of a sarcomeric, N2Bus-associated, mechanosensor complex, and blocks mitogen-activated protein-kinase signaling in this complex. Our work establishes PP5 as a compartmentalized, well-controlled phosphatase in cardiomyocytes, which regulates titin properties and kinase signaling at the myofilaments

Assessing indicators of runoff and erosion by rain simulation in the Ben Ahmed watershed (Central Morocco)

The objective of this study was to investigate the risks of runoff and erosion of soils in the Ben Ahmed watershed, it's located in the region of casa-settat, 70 km south-east of Casablanca, and characterized by a semi-arid climate. The study consists of measuring on 1 m2 plot, the volumes of runoff and sediments, under the influence of rainfall generation (60mm/30 min). Soil samples were collected from each plot to determine texture, organic matter and humidity. Results obtained show that the detachability varies between 19 and 34 g/l, infiltrability oscillate between 15 and 37 mm.h-. Pearson correlation test shows that infiltration was negatively correlated with runoff and soil detachability (R=-0.99, R=-0.87 respectively). It‘s significantly correlated with the proportions of sand(R=0.69), silt (R= -0.98) an clay (R= 0.92), however, is weakly correlated with organic matter (R=-0.32). Infiltration and detachability were significantly correlated with humidity (R = -0.99, R = -0.63respectively)

Ecodialysis: is it possible an eco-friendly system?

In medicine, attention to the environmental impact is still limited. Most of the analyses so far performed regard the last part of the cycle, the "grave of waste products". Chronic Hemodialysis produces about 600,000 tons of plastic waste per year. The economic crisis and the awareness of damage to the ecosystem progressively induced to focus attention on the lifespan of disposable, "from cradle to grave". A new outlook is presently focussed on recycle, that is the subsequent start of new cycles leading to a "from cradle to cradle" model: allowing a "new life" for the waste products, despite the need for initial investment. Aim of the present study is an analysis of the characteristics of the disposables employed in chronic hemodialysis, as a tool for identifying strategies limiting the environmental impact and containing the costs

Study of State Estimation Using Weighted Least Squares Method

Power state estimation constitutes the core of the on-line security analysis function. The challenge number one of a state estimator is to provide the optimal estimates of system state with minimum of measurement data. This paper describes weighted least squares state estimation method and investigates how the efficiency of WLS state estimation changes according to 4 parameters: number of measurements, measurement type, measurement weight and level of noise. Different simulation cases are tested on 3-bus system and IEEE 14-bus system. The results show that accurate estimates of system state can be obtained with minimum of measurement data on condition to choose a good combination of accurate measurements with a minimum of voltage measurements and power injection measurements and these data should be properly distributed throughout the system. For best results, the two factors (weight and noise) must be combined to obtain the best estimation. Indeed, the most accurate measurements (lower level of noise) should have greater weight compared to bad measurements (higher level of noise), specially voltage measurements due to their big impact

Ecodialysis: first strategies to limit damages and reduce costs

In the medical field, the attention to the environmental impact of industrial processes and products is still limited. In recent years there has been an increased sensitivity towards the environment; meanwhile, the economic burden of hazardous waste disposal is becoming evident. Dialysis is a "big producer" of waste and it has been estimated that disposal costs can be up to 10-40% of the cost of disposables. So there are several reasons of interest on "ecodialysis": the high amount of waste defined as "potentially hazardous", which requires a very expensive management and the recyclability potential of the non-contaminated waste, that has not yet been fully explored in dialysis. This primary study has been performed in collaboration with the Politecnico di Torino. Its aim has been to define a schedule of activities by a few brainstorming sessions. This schedule is to be readily performed or it should be developed in detail to optimize, by reducing and recycling, the waste production during the dialysis session. The discussion identified seven basic points for the eco-sustainability of haemodialysis to: [1] reduce packaging; [2] facilitate separation of materials, and [3] their discharge; [4] differentiate materials; [5] clearly highlight the potentially hazardous materials; [6] improve the recyclability of plastic products; [7] propose a path of recovery and reuse. Although a full optimization requires a close cooperation with the manufacturers and is achievable only in the long term, the reduction of one pound of potentially contaminated materials could presently lead, on a national scale, to a saving of several million euros, which can be better employed in investments to improve our treatments