Optimisation of the vehicle transmission and the gear-shifting strategy for the minimum fuel consumption and the minimum nitrogen oxide emissions

The paper outlines a computationally efficient analytical method for evaluating the fuel consumption and the nitrogen oxide emissions during manoeuvres pertaining to the New European Driving Cycle. An integrated optimisation procedure is also included in the analyses with minimisation of the brake specific fuel consumption and minimisation of the nitrogen oxide emissions as objective functions. A set of optimum gear ratios are determined for a four-speed transmission, a five-speed transmission and six-speed transmission as the governing parameters in the optimisation process. The analysis highlights the determination of gear-shifting objective-driven strategies based on the minimisation of either of the declared objective functions. A reduction of 7.5% in the brake specific fuel consumption and a reduction of 6.75% in nitrogen oxide emissions are attainable in the best-case scenario for a six-speed transmission and a gear-shifting strategy based on the lowest brake specific fuel consumption for the case of an engine. The novel integrated analytical simulations and multi-objective optimisation have not been hitherto reported in literature. It provides the opportunity for an objective intelligent-based approach to the use of gear shift indicator technology. The results of this study also show that transmission optimisation can act as an effective and inexpensive mean to enhance the fuel efficiency and to reduce the emissions

Effect of tapered roller bearing supports on the dynamic behaviour of hypoid gear pair differentials

Noise and vibration refinement and energy efficiency are the key drivers in powertrain development. The final drive (the differential) is a source of vibration concern and also contributes to the powertrain inefficiency. To optimise differential characteristics for the key objectives of refinement and efficiency, detailed models of the gear interactions as well as the support bearing dynamics are required. This study reports the integrated lubricated bearing and gear contacts with an eight-degree-of-freedom dynamic analysis (a tribo-dynamic model). Non-Newtonian shear behaviour of thin lubricant-film conjunctions is taken into account in the integrated tribo-dynamic analysis, which has not hitherto been reported in the literature. The results show that the transmitted vibration spectra from the system onto the differential casing are dominated by the bearing frequencies rather than by those due to the meshing of gears. It is also shown that a sufficiently high bearing preload improves the vibration refinement but can lead to a marginally reduced transmission efficiency

Impact of melatonin supplementation in the rat spermatogenesis subjected to forced swimming exercise

Oxygen consumption increases many times during exercise, which can increase reactive oxygen species. It negatively affects fertility in male athletes. Melatonin is exerting a regulatory role at different levels of the hypothalamic-pituitary-gonadal axis. However, there is no evidence that the protective effects of melatonin persist after long duration exercise on the spermatogenesis. Therefore, this study was conducted to examine the impacts of melatonin on the testis following the administration of swimming exercise. Rats were separated into five different groups, including Control, sham M: received the solvent of melatonin, M: received melatonin, S: the exercise protocol, MS: received melatonin and the exercise protocol. After 8weeks, animals were scarified and antioxidant enzymes levels of testes, spermatogenic cells apoptosis and sperm quality were measured. Swimming decreased all parameters of spermatozoa. Nevertheless, melatonin could significantly improve the progressive motility of spermatozoa in MS rats. Swimming caused an increased apoptosis of S group and decreased all antioxidant enzymes. Melatonin could drastically reduce apoptosis and increased these enzymes. Therefore, melatonin seems to induce the production of antioxidant enzymes of testicular tissues and diminish the extent of apoptotic changes caused by forced exercise on the testis, which can, in turn, ameliorate the sperm parameters

Enhancement of thermal and mechanical stabilities of silicon doped titanium nitride coating by manipulation of sputtering conditions

This study investigates the influence of substrate (AISI M42 tool steel) bias voltage (from −30 to −80 V), on the mechanical properties of magnetron sputtered TiSiN coating derived from Ti and Si targets. Thermal stability, microstructure (crystallite size, microstrain, lattice constant), morphology and mechanical (hardness, Young's modulus, residual stresses) properties, of the deposited TiSiN coatings, were investigated with synchrotron powered X-ray diffraction (SR-XRD), X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and nanoindentation techniques. Rietveld analysis, of the in-situ SR-XRD, in the temperature range of 25–800 °C, demonstrated cubic TiN form in (Ti,Si)N solid solutions, with TiO2 and Ti2O3 identified at lower bias voltages. Density functional theory supplemented the experimental results. Increase in the bias voltage resulted in: (i) a decrease in Si content, (ii) significant smoothening of surface morphology, (iii) change in the phase composition and microstructure, (iv) improved oxidation resistance and thermal oxidation threshold, and (v) hardness and Young's modulus of the coatings increased up to 50% to 33 GPa and 450 GPa, respectively

Ten questions concerning integrating smart buildings into the smart grid

Recent advances in information and communications technology (ICT) have initiated development of a smart electrical grid and smart buildings. Buildings consume a large portion of the total electricity production worldwide, and to fully develop a smart grid they must be integrated with that grid. Buildings can now be ‘prosumers’ on the grid (both producers and consumers), and the continued growth of distributed renewable energy generation is raising new challenges in terms of grid stability over various time scales. Buildings can contribute to grid stability by managing their overall electrical demand in response to current conditions. Facility managers must balance demand response requests by grid operators with energy needed to maintain smooth building operations. For example, maintaining thermal comfort within an occupied building requires energy and, thus an optimized solution balancing energy use with indoor environmental quality (adequate thermal comfort, lighting, etc.) is needed. Successful integration of buildings and their systems with the grid also requires interoperable data exchange. However, the adoption and integration of newer control and communication technologies into buildings can be problematic with older legacy HVAC and building control systems. Public policy and economic structures have not kept up with the technical developments that have given rise to the budding smart grid, and further developments are needed in both technical and non-technical areas

Quality assessment of services provided by health centers in Mashhad, Iran: SERVQUAL versus HEALTHQUAL scales

Background: Primary health care is the entry point to the health-care system and regarded as an essential step to achieving universal health coverage. The present study aimed at evaluating the quality of health-care services provided in health centers in Mashhad, Iran. Methods: This was a cross-sectional study implemented among 200 health service users who were referring to four health centers in Mashhad during January to June 2019. The quality of services in health centers was evaluated with the SERVQUAL and HEALTHQUAL models. Data was analyzed by employing paired t-test and independent sample t-test using SPSS version 16 software. The Levene test was used for examining the equality of variance (homogeneity). Significance level of all the tests was considered when p � 0.05. Results: According to the results of SERVQUAL questionnaire, the average scores of health service users� expectations and perceptions were 4.97 and 3.26, respectively, and the quality gap in the provided services was equal to � 1.7. Based on HEALTHQUAL questionnaire, the average scores of health service users� perception and expectations were 4.72 and 3.25, respectively, and the quality gap in the provided services was equal to � 1.16. Empathy was the highest quality dimension (� 2.019) based on SERVQUAL model, and efficiency dimension was the highest based on HEALTHQUAL model (� 1.761). Conclusions: The findings of the current study showed a negative gap between the service users� expectations and perceptions in both models. Therefore, the results of this study helps the health managers and policymakers to plan effective interventions for improving the provided services emphasizing the dimensions with the wider gaps. © 2021, The Author(s)

An analytical approach for prediction of elastohydrodynamic friction with inlet shear heating and starvation

An analytical friction model is presented, predicting the coefficient of friction in elastohydrodynamic (EHD) contacts. Three fully formulated SAE 75W-90 axle lubricants are examined. The effect of inlet shear heating (ISH) and starvation is accounted for in the developed friction model. The film thickness and the predicted friction are compared with experimental measurements obtained through optical interferometry and use of a mini traction machine. The results indicate the significant contribution of ISH and starvation on both the film thickness and coefficient of friction. A strong interaction between those two phenomena is also demonstrated, along with their individual and combined contribution on the EHD friction

Cryopreservation of rainbow trout (Onchorhynchus mykiss) semen

Breeding has moved beyond the point of simply propagating random stock. Genetic potential can be improved by establishing and crossing genetically defined strains, crossing species and manipulating gametes. Some of these activities require cryopreservation of semen. Cryopreserved sperm could also be a means of exchange of genetic material between locations and populations when transportation of live fish is restricted. In this study we had a survey on rainbow trout sperm quality in Genetic and Breeding Center for Coldwatwr Fishes, Shahid Motahari, Yasouj. Then Cryopreservation trials on rainbow trout (Oncorhynchus mykiss) sperm were carried out using six basic extenders. Egg batches of 25 g were inseminated with semen frozen in five 0.5-ml straws. Thowing temperature of cryopreserved sperm also was tested. In anather trial we investigate different cryoprotectant. The result showd that the best period for sperm collection in this center was from Novamber to January. The best extender based on sperm motility parameters were extender 2 and 1 with 57.2 and 56.9% fertilisatin rates, respectively. So this two extender were used in the further experiments. The best thowing temperathre was 25°C in 30s. Testing different cryoprotectant, adding 10% methanol to extender 1 gave the highest fertilization rate (64.6%) among cryoprotectant that used with this extender. In the other extender (2) adding 5% DMSO and mixture of 5% DMSO and 1% glycerol gave the highest fertilization rates (64.8% and 67.0%, respectively). In conclusion using extender 1 and 2 with mentioned cryoprotectant and thowing rate of 25°C in 30 s was recammended for rainbow trout sperm cryopreservation