The effects of the Fenton reagent on recycled unbleached pulp in the absence and presence of a model chemical contaminant, the p-hydroxybenzoic acid (HBA), were studied. In the absence of HBA, the Fenton system clearly modified the chemical and papermaking properties of the pulp. The kappa number was reduced and the specific light absorption coefficient was increased, indicating lignin modifica...

We present a new method to locally apply mechanical tensile and compressive force on single cells based on integration of a microfluidic device with an optical laser tweezers. This system can locate a single cell within customized wells exposing a square-like membrane segment to a functionalized bead. Beads are coated with extracellular matrix (ECM) proteins of interest (e.g. fibronectin) to ac...

statement of problem: currently there are three recognized theories about the diameter of prepared dowel space in endodontically treated teeth. diameter of the dowel is commonly contributed to the root fracture. purpose: this study used a 3 dimensional (3d) finite element method to predict stress distribution in endodontically treated central maxillary tooth with cast post and core with various...

BACKGROUND Previous experimental studies have been conducted to evaluate the biomechanical effects of posterior cruciate ligament reconstruction; but no consensus has been reached on the preferred method of reconstruction. METHODS The 3D finite element mesh of a knee joint was reconstructed from computed tomography and magnetic resonance images. The ligaments were considered as hyperelastic m...

The resulting internal stress situation in curing dental composites is still oversimplified due to analytical inaccessibility of local information of state and loading. Similar applies to the strength behavior of cured dental composites. Using recent progress of a finite-element-based curing model, we developed and attempted to benchmark dental composites based on their mechanical behavior and ...

In this paper, after collecting the rock samples from eight mines and one high way slope, the tests for determination of dry density, Uniaxial Compressive Strength, tensile Strength (Brazilian Test), elastic modulus, Schmidt hammer rebound number have been done on samples. In addition, in order to calculating the mean size of rock grains, quartz content, hardness and abrasivity, a thin sections...

The effects of Zr additive on the microstructure, mechanical properties, and fracture behavior of Al-Si alloy were systematically investigated. The additive of Zr obviously reduced the size of Si particles and changed its morphology. Grain size refinement was promoted by the reaction between Al and Zr forming Al3Zr and ZrSi2 compounds. Compared to a Zr-free alloy, the additive enhanced the tens...

The main purpose of this paper was to investigate the effect of a surface plastic deformation layer introduced by multi-pass ultrasonic surface rolling (MUSR) on the mechanical and fatigue properties of HIP Ti-6Al-4V alloys. Some microscopic analysis methods (SEM, TEM and XRD) were used to characterize the modified microstructure in the material surface layer. The results indicated that the mat...

Despite the numerous advantages of using concrete with high strength capacity, the brittle behavior of high strength concrete (HSC) and higher production cost has limited its use in the construction industry. This research aims to develop a cost-effective approach for production of high strength self-compacting concrete with desirable performance in either compressive or tensile loading conditi...

INTRODUCTION The aim of this study was to investigate the effects of thyroid hormones tri-iodothyronine (T3), thyroxine (T4), and parathyroid hormone (PTH) from the parathyroid glands, known to regulate the developing limb and growth plate, on articular cartilage tissue regeneration using a scaffold-free in vitro model. METHODS In Phase 1, T3, T4, or PTH was applied during weeks 1 or 3 of a 4...