Performa kendaraan bermotor dapat dilihat dari torsi dan daya. Baik tidaknya kualitas pembakaran akan mempengaruhi performa (torsi daya) sepeda motor, baiknya sejalan dengan performa. Proses di ruang bakar dipengaruhi oleh beberapa faktor seperti temperatur, densitas, turbulensi udara, serta komposisi udara bahan bakar. Peningkatan menjadi salah satu cara untuk meningkatkan mesin, dimana teknol...

In the first part of this paper, some theorems are given for a Riemannian manifold with semi-symmetric metric connection. In the second part of it, some special vector fields, for example, torse-forming vector fields, recurrent vector fields and concurrent vector fields are examined in this manifold. We obtain some properties of this manifold having the vectors mentioned above.

In this paper we will determine the multiple point manifolds of certain self-transverse immersions in Euclidean spaces. Following the triple points, these immersions have a double point self-intersection set which is the image of an immersion of a smooth 5-dimensional manifold, cobordant to Dold manifold $V^5$ or a boundary. We will show there is an immersion of $S^7times P^2$ in $mathbb{R}^{1...

The personal transportation choices that people make will have a drastic impact on air quality. What the commute with and how they environment. pollutants an additional human life as these particulate matter cause respiratory diseases elevated risk of cancer. To improve this dire situation, several steps been adopted by automobile companies worldwide over past 20 years. emission fuel consumptio...

In this paper the intake manifold as the most effective part on engine’s volumetrice efficiency is in vestigated in detail with emphesizing on flow behavior and characterestics. The eight different design have been  prepared  and  imported to CFD software. Five objective functions for investigation of flow have been connsidered and applied in TOPSIS with different weights. Mass flow rate,massfl...

commutative properties of four-dimensional generalized symmetric pseudo-riemannian manifolds were considered. specially, in this paper, we studied skew-tsankov and jacobi-tsankov conditions in 4-dimensional pseudo-riemannian generalized symmetric manifolds.

In this paper, a third order nonlinear model of the airpath of a turbocharged diesel engine is derived, which is then converted into linear parameter-varying (LPV) form with the intake and exhaust manifold pressure as parameters. The model predicts the mass air flow (MAF) and manifold absolute pressure (MAP) based on the EGR and VGT actuator positions, speed, and load. A comparison to experimen...

in this paper, we obtain a necessary and sufficient condition for a conformal mapping between two weyl manifolds to preserve einstein tensor. then we prove that some basic curvature tensors of $w_n$ are preserved by such a conformal mapping if and only if the covector field of the mapping is locally a gradient. also, we obtained the relation between the scalar curvatures of the weyl manifolds r...

The aim of this paper is to characterize $3$-dimensional $N(k)$-paracontact metric manifolds satisfying certain curvature conditions. We prove that a $3$-dimensional $N(k)$-paracontact metric manifold $M$ admits a Ricci soliton whose potential vector field is the Reeb vector field $xi$ if and only if the manifold is a paraSasaki-Einstein manifold. Several consequences of this result are discuss...