1-type and biharmonic curves by using laplace operator in lorentzian 3-space arestudied and some theorems and characterizations are given for these curves.

proton exchange membrane fuel cells (pemfcs) with a dead-ended anode and cathode can obtain high hydrogen and oxygen utilization by a comparatively simple system. nevertheless, the accumulation of the water in the anode and cathode channels might cause a local fuel starvation degrading the performance and durability of pemfcs. in this study, a brand new design for a polymer electrolyte membrane...

decline curve analysis has some advantages over transient well test analysis in which it is not required to shut-in the well and also wellbore storage effects do not exist. few studies have been done on decline curve analysis of naturally fractured reservoirs but there are even some limitations with available models. on the other hand well test could be expensive and in some operational conditi...

A disk Wang-Bézier type generalized Ball curve is a Wang-Bézier type generalized Ball curve whose control points are disks in a plane. It can be viewed as a parametric curve with error tolerances. In this paper, we discuss the problem of degree reduction of disk Wang-Bézier type generalized Ball curve, that is, bounding disk Wang-Bézier type generalized Ball curves with lower degree disk Wa...

A disk Wang-Bézier type generalized Ball curve is a Wang-Bézier type generalized Ball curve whose control points are disks in a plane. It can be viewed as a parametric curve with error tolerances. In this paper, we discuss the problem of degree reduction of disk Wang-Bézier type generalized Ball curve, that is, bounding disk Wang-Bézier type generalized Ball curves with lower degree disk Wa...

In this study, we introduce a new type of surface curves called $D$-type curve. This curve is defined by the property that the unit Darboux vector $vec{W}_{0} $ of a surface curve $vec{r}(s)$ and unit surface normal $vec{n} $ along the curve $vec{r}(s)$ satisfy the condition $leftlangle vec{n} ,vec{W}_{0} rightrangle =text{constant}$. We point out that a $D$-type curve is a geodesic curve or an...

a disk wang-bézier type generalized ball curve is a wang-bézier type generalized ball curve whose control points are disks in a plane. it can be viewed as a parametric curve with error tolerances. in this paper, we discuss the problem of degree reduction of disk wang-bézier type generalized ball curve, that is, bounding disk wang-bézier type generalized ball curves with lower degree disk wang-b...

background: the homeostasis model assessment of insulin resistance (homa-ir) is a useful model for application at large epidemiologic studies. the aim of this study was to determine the homa cut off values to identify insulin resistance (ir) and metabolic syndrome (ms) in qazvin, central iran. methods: overall, 480 men and 502 women aged 20-72 yr attended in this cross sectional study from sept...

the objective of the present study was to estimate the lactation curve parameters through incomplete gamma function and to genetically evaluate the relationship of these parameters and udder traits in holstein population of iran. two data sets' including 117583 [(for lactation curve parameters) and 7351 (for determining genetic and phenotypic relationship between lactation curve parameters...