Construction of geothermal wells that are effectively cemented and durable poses a significant operational challenge. Typically, lost circulation while drilling and cementing can make it seemingly impossible to place a complete column of cement behind casing strings. Incomplete cementation can lead to well failure caused by cyclic temperature loading on the casing that occurs throughout the lif...

OBJECTIVE To study the results of implantation of preformed hydroxyapatite (HA) disks and HA cement in onlay augmentation. METHODS In this prospective study involving 16 adult New Zealand rabbits, HA disk and HA cement samples were implanted separately and together along the bony and cartilaginous nasal dorsum as well as over the supraorbital bone. Gross and histologic examinations of the imp...

A number of results for reactions involving subdiffusive species, all with the same anomalous exponent , have recently appeared in the literature and can often be understood in terms of a subordination principle whereby time in ordinary diffusion is replaced by tgamma. However, very few results are known for reactions involving different species characterized by different anomalous diffusion ex...

We show that if G is any p-group of class at most two and exponent p, then there exist groups G1 and G2 of class two and exponent p that contain G, neither of which can be expressed as a central product, and with G1 capable and G2 not capable. We provide upper bounds for rank(Gi ) in terms of rank(G) in each case.

We obtained the global persistence exponent for a continuous spin model on the simple cubic lattice with double-exchange interaction by using two different methods. First, we estimated the exponent theta(g) by following the time evolution of probability P(t) that the order parameter of the model does not change its sign up to time t[P(t) approximately t(-theta(g)]. Afterwards, that exponent was...

Bone cement containing gentamicin may release antibiotic when fractured during revision operations. Tissue samples taken during surgery may be contaminated by gentamicin and give inaccurate microbiological assessment. We studied five patients in whom cement containing gentamicin had been used in the primary procedure. During revision hip replacement, samples of joint fluid, tissues and cement w...

Ordinary Portland Cement (OPC) is often used for the solidification/stabilization (S/S) of waste containing heavy metals and salts. These waste components will precipitate in the form of insoluble compounds on to unreacted cement clinker grains preventing further hydration. In this study the long term effects of the presence of contaminants in solidified waste is examined by numerically simulat...

The feasibility of calcium carbonate cements involving the recrystallisation of metastable calcium carbonate varieties has been demonstrated. Calcium carbonate cement compositions presented in this paper can be prepared straightforwardly by simply mixing water (liquid phase) with two calcium carbonate phases (solid phase) which can be easily obtained by precipitation. An original cement composi...

Introduction: In cemented total hip arthroplasty, the implant needs a mechanically stable cement-bone interface for its survival. This can be achieved by adequate cement penetration into the bone lacunar and trabecular spaces. Many studies have been conducted to investigate the strength of the cement-bone interface in relation to the amount of cement penetration, but mainly on a macro-scale [1]...

BACKGROUND The aim of this study is to evaluate the effect of self-invented compound calcium phosphate cement upon the proliferation and osteogenesis of bone mesenchymal stem cells (BMSCs). METHODS Four groups including traditional calcium phosphate cement, modified calcium phosphate cement, modified calcium phosphate cement plus bone morphogenetic protein (BMP), and control groups were estab...