Examınatıon of Surface Qualıty by Applyıng Taguchı Experıment Desıgn in The Processıng of Natural Stones Wıth Cnc Machıne

In this study, the natural stone CNC machine, which leads to minimum surface roughness with the Taguchi experimental design method, provides an approach to determine milling process parameters (cutting speed, feed rate and cutting depth). Milling operations in 14 natural stones, using a orthogonal array L9, Taguchi experiment design method was performed. S/N based on a “smaller, better” approach to determine optimal levels of processing parameters was calculated separately for each natural stone. Analysis of variance (ANOVA), Correlation and regression analysis application, petrographic and physical-mechanical properties of processing parameters and natural stones were used to examine the effects of surface roughness. The results of this study show that cutting depth has the most important effect. When petrographical properties of the natural stones are evaluated, the average grain size of the rocks plays an important role especially in surface purge.Bu çalışmada, Taguchi deney tasarımı yöntemi ile minimum yüzey pürüzlülüğüne yol açan Doğaltaş CNC makinesi frezeleme işleme parametrelerini (kesme hızı, ilerleme hızı ve kesme derinliği) belirlemek için bir yaklaşım sunmaktadır. Frezeleme işlemleri 14 adet doğaltaşta, bir ortogonal dizi olan L9 kullanılarak Taguchi deney tasarım yöntemi gerçekleştirilmiştir. İşleme parametrelerinin optimum seviyelerini belirlemek için “daha küçük olan daha iyi” yaklaşıma dayanan S/N her bir doğaltaş için ayrı ayrı hesaplanmıştır. Varyans analizi (ANOVA), korelasyon ve regresyon analizi uygulaması, işleme parametrelerinin ve doğaltaşların petrografik ve fiziko-mekanik özelliklerinin yüzey pürüzlülüğü üzerindeki etkilerini incelemek için kullanılmıştır. Bu çalışmanın sonuçları, kesme derinliğinin en önemli etkiye sahip olduğunu göstermektedir. Doğaltaşların petrografik özellikleri değerlendirildiğinde, özellikle kayaçların ortalama tane boyutu yüzey pürüzlülüğünde önemli rol oynamaktadır

Uszkodzenie gałęzi powierzchownej nerwu promieniowego i gałęzi unerwiającej mięsień ramienno-promieniowy związane z kostniakochrzęstniakiem części bliższej kości promieniowej

The cutaneous branch of the radial nerve (superficial radial nerve, SRN) might be compressed or injured at various anatomical sites along its course in the forearm. Compression of the SRN occurring at the proximal third of the forearm is unusual. A 22-year-old man was admitted with pain and paraesthesia over the lateral aspect of his right wrist and thumb and pain at the elbow for six months. In electrodiagnostic testing, a sensory nerve action potential from the right SRN could not be recorded, while it was normal on the left. In a needle electromyography study, denervation potentials have been seen in the right brachioradial muscle and a decrease in interference pattern signals was also found. An exophytic lesion of the proximal radius was observed in radiographs. Computed tomography evaluation revealed an osteochondroma of the proximal radius. Neuropathies of the SRN and the brachioradial motor branch of the radial nerve are thought to be associated with proximal radial osteochondroma.Gałąź skórna nerwu promieniowego, nerw promieniowy powierzchowny, może zostać uciśnięta lub uszkodzona w różnych lokalizacjach anatomicznych na swoim przebiegu w przedramieniu. Ucisk nerwu promieniowego powierzchownego występujący w jednej trzeciej bliższej przedramienia jest rzadkością. Mężczyzna, lat 22, został przyjęty z powodu bólu i parestezji na bocznej powierzchni prawego nadgarstka i kciuka oraz bólu w okolicy łokcia, utrzymujących się od 6 miesięcy. W badaniu przewodnictwa nerwowego stwierdzono brak czuciowych potencjałów czynnościowych z prawego nerwu promieniowego powierzchownego; po stronie lewej potencjały takie były prawidłowe. W elektromiografii igłowej stwierdzono potencjały odnerwienia i zmniejszony zapis interferencyjny w prawym mięśniu ramienno-promieniowym. Na zdjęciach przeglądowych stwierdzono egzofityczną zmianę w obrębie części bliższej kości promieniowej. Obraz tomografii komputerowej wskazywał na kostniakochrzęstniaka części bliższej kości promieniowej. Uznano, że stwierdzone uszkodzenia nerwu promieniowego powierzchownego i gałęzi ruchowej nerwu promieniowego zaopatrującej mięsień ramienno-promieniowy są związane z obecnością tego guza

Relationship Between Characteristics of Stenotic Plaque in Carotid Artery and Ischemic Stroke Recurrence

OBJECTIVE: Quantification of stenosis, plaque morphology and surface characteristics by doppler sonography and prediction of plaque rupture risk are important for treatment options in ischemic stroke. OBJECTIVE: We evaluated the association of carotid plaque characteristics and the risk of recurrent ischemic stroke. METHODS: Carotid plaques were ultrasonographically evaluated within ten days in 79 acute anterior circulation ischemic stroke patients without source of cardiac emboli. The subsequent incidence of transient ischemic attack, minor and major stroke was investigated wtihin six months period. During follow-up, 20 strokes occurred. Logistic regression analysis was used to determine the relation between plaque morphology and recurrent stroke risk. RESULTS: Patients with an ulcerated plaque had an 8.7-fold higher risk of recurrent stroke than those without ulceration (p<0.001). Patients with a hypoechogenic plaque had a 1.78-fold higher risk of recurrent stroke than those with hyperechogenic plaque (p<0.001). Patients with a functional stenosis greater than 70% had a 5.25-fold higher risk of recurrent stroke than those with a functional stenosis lesser than 70% (p<0.001). CONCLUSION: Plaque ulceration, hypoechogenicity and increased stenosis are independently associated with a higher risk of stroke recurrenc

Diagnostic Clues in Multiple System Atrophy: A Case Report and Literature Review

Multiple system atrophy (MSA) is an adult-onset, sporadic, progressive neurodegenerative disease. According to the consensus criteria, patients with MSA are clinically classified into cerebellar (MSA-C) and parkinsonian (MSA-P) subtype. Besides the poor response to levodopa, and the additional presence of pyramidal or cerebellar signs (ataxia) or autonomic failure as major diagnostic criteria, certain other clinical features known as ‘‘red flags’’ or warning signs may raise the clinical suspicion of MSA. Case report: A 67-year-old woman was admitted to our hospital due to inability to walk. Neurological examination revealed severe Parkinsonism with poor response to levodopa therapy, ataxia. Brain MR imaging showed severe atrophy of the cerebellum, pons, minimal cerebrum, and revealed cross section at the pons in the axial section. Mini-Mental State Examination (MMSE) was normal, Median SEP within normal limits but left Tibial SEP was longer than right side (right: 41, left: 44.2). Although sympathetic skin response of upper extremities was normal, the sympathetic skin responses of lower extremities were absent. RR interval study and a graded head-up tilt test were consistent with autonomic dysfunction. We report a patient with MSA because in clinical practice a case who fullfits all criteria is really rare

Status Epilepticus Associated with Ecstasy

Status epilepticus (SE) is a life-threatening emergency condition. In addition to well-known etiological factors, many rare causative factors have also been defined. Ecstasy (3,4-methylenedioxy-N-methylamphetamine) is an amphetamine derivative known to cause SE. Presently described is a case of recurrent SE in which ecstasy was an etiological factor

A Case with POEMS Syndrome Presenting with Loss of Vision and Skeletal Muscle Strength

POEMS syndrome (osteosclerotic myeloma) is a plasma-cell proliferative disorder and a combination of several organ system manifestations. The term POEMS is an acronym for polyneuropathy, organomegaly, endocrinopathy, monoclonal proteinemia and skin changes. Although the diagnostic criteria have been modified in time to cover those findings that are seen more frequently but are less specific to make a certain decision, the rare nature of the disease may also be associated with the fact that many patients present with symptoms or signs which are thought to be related to certain organ systems. Here we present a case of POEMS syndrome with almost complete visual loss, dyspnea and loss of sceletal muscle strength and their significant recovery after treatmen