Effects of Impurities and their Redistribution during Recrystallization of Ice Crystals

In order to examine the effects of solutes on recrystallization and subsequent grain growth in ice, both doped and undoped ice single crystals were extruded through a 120o equal-channel angular extrusion jig, in order to impart a large shear strain (~1.15). Upon subsequent annealing at –3o C, the original single crystals recrystallized, in most cases to a new single crystal with a different orientation. Increasing the solute concentration (for H2SO4 to ~200–300ppb, and for NaCl, KCl and MgSO4 to \u3e5ppm) was found to significantly retard the growth and possibly, for H2SO4-doped ice, the nucleation of new grains in the strained ice single crystals. This is indicative of how soluble impurities can retard grain growth in ice cores. It was also found that the migrating grain boundaries surrounding the newly formed grains contained large concentrations of impurities, often observed as filaments. These could have formed by the grain boundaries sweeping up impurities from the lattice into the boundary or by their diffusion to the boundary–mechanisms whereby impurities could be concentrated into the grain boundaries in ice cores– although the latter mechanism seems unlikely since it would require very high diffusion rates

The implementation of a novelty concept and measurement model for a developing B2B marketplace

Regardless of the market on which the company operates - B2B or B2C, brand and customer experience are the keys to success in the modern world. The B2C companies succeeded in adapting to the new trends, while B2B companies didn’t keep pace and missed the opportunity to experience the competitive advantage. The purpose of this work is to assess the brand equity through its elements – brand associations, brand attitudes, brand loyalty and other services and to identify the metrics such as Customer Lifetime Value and Retention that enforce the overall customer equity (Fig. 3.2.1). The literature was analysed and the approaches regarding brand equity and customer equity and the linkage between them were reviewed. Subsequently, the model proposed by Leone et al (2006) guided research in order to answer to the following questions: “Does a brand differentiate a distributor?” and “Are the brand equity and customer equity related in the Romanian developing B2B market?”, The quantitative research applied in this paper on a sample of 110 people from the cash- generators category showed that the brand equity is influenced by loyalty in a proportion of 29.9%. However, the conclusion is that it cannot be assumed a linear relation between brand and customer equity in the current research, from the perspective of a tyre and construction materials distributor, that operates in a developing economy. The recommendations highlights loyalty as an essential asset for Dynamic 92 who experiences long-term relationships and promising recommendations (see Net promoter score is over 70%) However, the customers are not alike and therefore the implementation of Customer Lifetime Value as a managerial KPI used in modern economies, assists the sales managers to evaluate the purchasing behaviour of up mentioned customers, to monitor their retention and the customer’s cost centre. This project could generate the company’s empowerment by the novelty and differentiation in the Romanian environment and it ensures the conditions for the company to compete with international distributors, on equal terms/positions

Mechanical failures of ventriculo-peritoneal shunts

Ventriculo-peritoneal (VP) shunt placement represents the most widely accepted form of treatment for most patients with hydrocephalus. Despite significant improvements in VP shunt procedures, various complications remain a common situation. The diagnosis of shunt failure can be confounded by a variety of factors, mechanical failure being the most common cause of multiple shunt revisions in a lifetime. A better understanding of mechanisms of shunt failure will cause an improvement in the management of this neurosurgical procedure

Our experience in surgical treatment of intraorbital tumors

Orbital tumors are complex lesions representing a great challenge for the neurosurgeons and ophthalmologist.Methods: We analyse the database for 57 patients who underwent surgery for the treatment of orbital tumors at our institution between 2001 and 2010. Data from clinical notes, surgical reports, and radiological findings were extracted for the statistical analysis.Results: Predominant symptoms were exophthalmos (68%), visual disturbance (42%) and ocular mobility limitation (37%). The most used surgical approache was superior orbitotomy. Orbital tumors histopathological results showed that hemangiomas were the most common tumors type (35%). Malignant tumors accounted for 23% of cases. Total resection of tumors was achieved in 78% of patients.Conclusion: Surgical treatment could be considered an optimal treatment option for most of the orbital tumor. A better imaging anatomy analysis of the orbit correlated with good surgical skills is needed to overcome the pitfalls of intraorbital surgery

Technique possibilities for volumetric assessment of intracranial aneurysms

Volume measurement techniques of intracranial aneurysms from 3D rotational angiography vary on different factor settings and, therefore, are operator-dependent. The purpose of this study was to evaluate the application and the precision of ellipsoidal approximation (mathematics and computer technique) and software methods to measure intracranial aneurysms volume starting from planar (DR and SD) and 3-dimensional (3D) angiographic images. The reliability of the methods was statistically compared in a clinical setting of 42 angiograms and 100 measurements performed by the same users. This study suggests that both techniques could be used for clinical applications with similar efficiency results. The 3D rotational angiography is an increasingly used method for cerebral aneurysms treatment planning. This complex imagistic method permits a better evaluation of cerebral aneurysms anatomy by an improved delimitation of vessels and aneurysms contours. Moreover, the 3D dataset can be used to calculate aneurysm volume. It is known the important role of aneurysm volume calculation in coil embolization treatment. To assess an optimal degree of coils aneurysm packing, it has become imperative to determine preoperatively the volume of the aneurysm to be embolized

Severe spinal stenosis in an adult achondroplastic dwarf: Case report

Achondroplasia is the most common form of human short-limbed dwarfism and is one of a spectrum of diseases caused by mutations in the FGFR3 gene. Achondroplasia is estimated to occur in 1 in 10,000–30,000 live births4,7. The disease is autosomal dominant, but 80% of patients have new mutations. It is commonly associated with several neurological conditions such as hydrocephalus, cervicomedullary compression, cervical or thoracic cord compression, and lumbar spinal compression due to bone stenosis along the neuraxis. We report a case with severe spinal stenosis at the lumbar and thoracic levels, with minimal involvement of the cervical spine with late neurological onset in an adult patient with achondroplasia. Neurological and radiological findings and surgical procedures are discussed. The patient was admitted with profound spastic lower paraparesis and urinary incontinence. In the first operation we performed lumbar decompression and the patient improved and on the fifth day she was able to take a short walk. 3 months after the first surgery we intervened on the thoracic spine with a multi-level decompression which allowed for further neurological improvement, continued in a specialized medical facility. The case stands out as the clinical picture was dominated by the lumbar stenosis (although both lumbar and thoracic stenosis were severe at the time of presentation) with a late onset and sparing of the cervical spine

First experience in intracranial aneurysm occlusion by balloon assisted coiling technique

Particular anatomical situation like wide-neck aneurysms or a large neck/fundus ratio, located on an arterial bifurcation or a small artery, are still a challenge for endovascular coil occlusion. These are due to the risk of coil migration or coil protrusion into the parent vessels. In our study we describe the balloon assisted coiling technique regarding the efficacy and safety of its practice and the problems that could appear

Traumatic intracranial aneurysms

Traumatic intracranial aneurysms are rare conditions that can be a result of vast head trauma. Different aspects as history, etiology, histopathology, clinical manifestations, diagnosis and treatment options are discussed regarding the literature. A particular case of a pericalosal aneurysm is presented to highlight the importance of keeping in mind that this location can be a site of such aneurysms