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An analytical model has been developed to estimate the collecting area of a “gapped” single Langmuir probe flush to a local limiter, when the probe characteristic dimension perpendicular to the magnetic field direction is comparable to the ion Larmor radius. The problem has been solved for angles between the magnetic field direction and the probe surface between 12° and 42°, and for square and circular probe cross-sections. A numerical model, adopting a Montecarlo type approach, has also been developed in order to generalize the solution. Both models also estimate the dependence of the collecting area on the sheath thickness. The models are in good agreement and have been applied to the probes used on the RFX experiment.

In this paper the diagnostic systems implemented on the reversed field pinch (RFP) experiment RFX are presented. The paper is mainly concerned with the general engineering aspects and with the development work addressed to meet specific requirements such as immunity to electrical noise, ultrahigh vacuum compatibility, reliability. A general guideline adopted in the development of diagnostics was to use, whenever possible, proven methods, at least for the systems dedicated to the measurement of the most significant parameters. Each section of the paper illustrates a different system, in which the diagnostic constraints and the specific choices derived from the peculiarities of the RFP configuration are discussed. Although the majority of the diagnostic instruments are at present fully developed and operational, some of them, i.e. far-IR polarimeter, microwave reflectometer, soft X-ray and bolometer tomographic system are either under prototype testing or under construction.

A 5-year-old female infant with a extremely rare combination of Pierre Robin syndrome and multiple malformations of the limbs and kidneys is presented. Orthopaedic, hearing, intellectual and speech disabilities and treatment difficulties are discussed.

EX/P4-13 · The Greenwald density limit in the Reverse Field Pinch M. Valisa1), F. Auriemma, A. Canton, L. Carraro R. Lorenzini, S. Ortolani, R. Paccagnella, M.E. Puiatti, F. Sattin, P. Scarin, G. Spizzo, M. Spolaore, N. Vianello, A. Alfier, V. Antoni, L. Apolloni, M. Bagatin, W. Baker, O. Barana, F. Basso, D. Bettella, P. Bettini, T. Bolzonella, D. Bonfiglio, A. Buffa, S. Cappello, R. Cavazzana, M. Cavinato, G. Chitarin, A. Cravotta, F. D'Angelo, S. Dal Bello, M. Dalla Palma, A. De Lorenzi, L. De Pasqual, D. Desideri, D.F. Escande, P. Fiorentin, P. Franz, L. Frassinetti, G. Gadani, E. Gaio, L. Garzotti, E. Gazza, L. Giudicotti, F. Gnesotto, L. Grando, S.C. Guo, P. Innocente, A. Luchetta, G. Malesani, G. Manduchi, G. Marchiori, D. Marcuzzi, L. Marrelli, P. Martin, E. Martines, S. Martini, A. Masiello, F. Milani, M. Moresco, A. Murari, P. Nielsen, R. Pasqualotto, S. Peruzzo, R. Piovan, P. Piovesan, N. Pomaro, G. Regnoli, G. Rostagni, V. Schmidt, G. Serianni, P. Sonato, E. Spada, C. Taliercio, D. Terranova, V. Toigo, P. Zaccaria, P. Zanca, B. Zaniol, L. Zanotto, E. Zilli, G. Zollino, M. Zuin 1) Consorzio RFX - Associazione EURATOM-ENEA sulla Fusione, Padova, Italy Abstract: In the Reversed Field Pinch RFX the density operating space exhibits an upper boundary that is well described by the Greenwald limit. The basic findings are described and similarities and differences with the Tokamak case are analysed. The high-density limit occurs as a non-disruptive limit. Fast terminations have been observed but in a wide area of the operating space and therefore are unlikely to be related to the density limit. Radiation induced thermal collapse can also be ruled out being radiation losses always a relatively small fraction of the ohmic input power. The occurrence of plasma detachment while approaching the density limit can be excluded. The absence of additional heating makes it difficult to distinguish with certainty between a power balance effect and an intrinsic physical limit but the overlapping of the Greenwald limit with the upper boundary of the density operating space is however remarkable, especially in the case of He plasmas . While in Tokamaks one of the plausible causes for the limit is a transport induced edge thermal instability, in RFX, as density increases the density profile becomes hollow, inside the last closed magnetic surface particle diffusion decreases and the global energy confinement time improves. The normalised density fluctuations measured by Langmuir probes and by the outermost chords of an interferometer do not increase. Simulations of the hydrogen discharges with the RITM code confirm the importance of recycling in determining the edge density gradient and the minor role of radiation losses. Differences between H and He cases are analysed in terms of particle penetration capability and in terms of edge ExB shear. A statistical analysis of the edge density fluctuations is presented, looking for differences arising as density is increased. Finally, the possible role of pressure driven modes is discussed.

The results of an extensive investigation of electrostatic and magnetic turbulence in the edge region of two Reversed Field Pinch (RFP) experiments EXTRAP-T2R and RFX are reported . In both experiments particle transport is mostly driven by electrostatic turbulence and a highly sheared ExB flow takes place. Recent results have shown that almost 50% of the particle losses is due to coherent structures. These structures have features reminiscent of monopolar or dipolar vortices and their relative population and preferred vorticity is determined by the local ExB shear. It has been demonstrated that the plasma diffusivity D can be separated in two comparable terms: one due to coherent structures and another one due to background turbulence. The ExB shear results to affect both terms, modifying the populations of vortices and the phase of background density and velocity fluctuations . This effect has been proved by several experiments of transport control based on modification of the ExB shear by insertion of active electrodes or by applying transient modifications of the magnetic field. In order to investigate the process responsible for the observed ExB flow profile, the momentum balance has been recently addressed and it has been found that also transport of momentum is anomalous as experimental kinematic viscosity results consistent with anomalous diffusion. Moreover the balance reveals that plasma flow profile is regulated by turbulence and in particular by the electrostatic component of the Reynolds Stress (RS). These results prove the existence of a dynamic interplay between turbulence properties, anomalous transport and mean profiles. All results are discussed highlighting the similarities with other magnetic configurations.

The results of an extensive study on transport mechanisms and on improved confinement scenarios in RFX are reported. The scaling of the thermal conductivity in the core with the Lundquist number indicates that the magnetic field in this region is not fully stochastic, as proved by the existence of thermal barriers observed in single helicity configurations. The electrostatic transport at the edge has been proved to depend on the highly sheared E × B flow, which has been interpreted using fluid and Monte Carlo models. Regimes of improved confinement have been obtained in the core by poloidal current drive techniques, and the electrostatic transport has been reduced at the edge by biasing experiments. A radiation mantle caused by impurity seeding has been found to successfully reduce the local plasma-wall interaction without causing a significant deterioration in the plasma performance.

The particle and energy transport mechanisms have been investigated in RFX. In the core the particle diffusivity and thermal conductivity are consistent with a stochastic magnetic field model. At the edge particle transport is mainly driven by electrostatic fluctuations, whereas radiation, electrostatic and magnetic turbulence account only for 50% of the total energy losses.

This paper presents an overview of recent experimental results obtained on the RFX device. We succeeded in obtaining and study RFP plasma with a plasma current up to 1 MA with negligible radiation losses and low effective charge. The local power and particle balance shows that in standard operation the plasma core is dominated by magnetic turbulence and that the global confinement is mainly provided by the edge region where a strongly sheared radial electric field is present. With poloidal current drive the amplitude of magnetic fluctuation and the thermal conductivity of the plasma core are reduced leading to improved confinement. Reduced heat transport is also observed when the width of the n spectrum of magnetic fluctuations is reduced.

Although civilian populations have been heavily involved in most of the recent wars and conflicts throughout the world, most reports analyzed casualty data of military personnel, often leaving civilian casualties excluded or underestimated. A comparison of epidemiologic and medical data for maxillofacial injuries between civilians and servicemen (policemen, soldiers, and United Nations Protection Forces) during the aggression against Croatia is attempted. Of the 220 casualties admitted to the Department of Maxillofacial Surgery in Zagreb between August 1991 and December 1992, almost one-fourth were civilians. A significant difference between civilians and servicemen was noted in age and sex distribution. The incidence and severity of maxillofacial and associated injuries is almost equal, and the pattern of injuries is of the same type for civilian and military personnel.

A power supply system for Langmuir probes to be used on the reversed field pinch (RFP) thermonuclear fusion experiment RFX has been developed. It is based on a full-bridge converter concept, using a pulse width modulation (PWM) technique, and is characterized by a 5 A, +or-150 V rating. The power supply has been designed to ensure compatibility with the electromagnetic noise close to the machine and with the plasma, which behaves as a nonlinear rapidly varying load. The system has been optimized by numerical simulations. Tests in the laboratory and on the experiment have been performed in a wide range of working conditions and the system has been proven to suit fairly well the RFX experimental conditions.

On the basis of three case reports, different treatment modalities of primary hyperparathyroidism of the jaws are presented. Surgical intervention made as the result of misdiagnosis in the first case caused an unnecessary bone defect and delayed bone regeneration for several months. Two other cases showed spontaneous regeneration of bone after parathyroidectomy. The second case disproved the earlier opinion that regeneration of the bone lesions could last for several years, and that the normal morphology could be restored. Complete resolution of the central giant-cell lesion was found 6 months after removal of the parathyroid adenoma.

Potreba za što jednostavnijim, rutinski prihvatljivim, morfološkim istraživanjem maksilarnog luka kod rascjepa usne i nepca rezultirala je novom, originalnom, objektivnom kompjutoriziranom analizom. Metoda iznesena u ovom radu pogodna je za kliničku dokumentaciju, praćenje i za znanstveno istraživanje rascjepa. Set oznaka i faktora daje »ratio-odnos« asimetrije ili pomaka segmenta, umjesto apsolutnih brojeva, što je pogodnije za uspoređujuća ispitivanja i praćenja., The need for a simple, routinely applicable method for morphologic analysis o f maxillary arch in cleft patients resulted in development of a new original, objective and computerized method. The authors present the rationale and procedure o f this method which is extremely suitable for clinical documentation, follow up and clinical investigation o f cleft patients. The descriptive factors are expressed in relative numbers — rations of asymmetry and segment displacement. The relative numbers enable comparative analysis between arches of different size.

Radi analize karakteristiika bolesnika sa prijelomom donje čeljusti i provjere uspješnosti liječenja, retrospektivno su ispitani bolesnici sa prijelomom mandibule koji su boravili na Klinici za kirurgiju lica čeljusti i usta od 1. 1. 1984. do 31. 7. 1985. Analiza pokazuje da je 196 bolesnika imalo 281 prijelom, najviše na korpusu mandibule 121 (43,1 °/0), zatim na kondilarnom nastavku 68 (24,2%), a najmanje na alveolarnom grebenu 7 (2,5%). Gotovo jednako često uzroci prijeloma bili su promet (33,7) i nasilje (31,6%). Po dobi najugroženije je 3. desetljeće. U 51% slučajeva provedeno je konzervativno liječenje, a osteosinteza žicom primjenjena je kod 67 bolesnika. Ukupno je bilo 26 (13,3%) komipllikacija, među kojima se naročito ističe visok postotak kod osteosinteza jednom od pločica (standardna 30%, AO 50%). Rezultati pokazuju da su prijelomi donje čeljusti i dalje česti, da je konzervativno liječenje zadovoljavajuće za većinu prijeloma, a da osteosintezu pločicom treba primijeniti samo u strogo indiciranim slučajevima., In order to analyse the characteristics of the patients suffering from mandibular fractures and to test the succsess of the treatment, we retrospectively investigated patients with the fracture of the mandible, hospitalized in the period between January 1, 1984. and July 31, 1985. It has been shown that 196 patients had 281 fractures, predominantly in the corpus area of the mandible, 121 (43, 1°/o), followed by the condylar process, 68 (24, 2%), while the alveolar process was the least frequently affected, 7 (2, 5%). Almost with equal frequency, traffic (33,7%) and physical violence (31,03%) were responsible for the fractures. The third decade appeared to be the most dangerous age with 40,3%. In 51% of the patients the conservative treatment was performed, while wire osteosynthesis was applied in 67 patients. Altogether, there were 26 (13,3%) patients with complications, among which a very high percentage, 30% for standard plate and 50% for AO plate, stands out. Results show that the mandibular fractures are still frequent; that the conservative treatment is satisfactory for most of the fractures, and that the plate osteosynthesis should be done only in strictly indicated cases.

An unusual case of a double congenital epulis involving the alveolar mucosa of both the maxilla and mandible is reported. The authors discuss the clinical picture, histological findings, etiology and treatment of this rare lesion.

Hearing threshold in cleft lip/or palate was assessed in 316 ears by pure tone audiometry. Normal hearing threshold was found in almost a half (164/51,9%) of the ears examined. Hearing defects were most frequently observed in cases of complete unilateral cleft palate (48/60%), whereas they were least frequently recorded in cases of cleft lip (15/19,2%). Complete bilateral cleft lip and palate was associated with conduction deafness in 29 (42,9%) ears examined, thus occupying the last but one place according to the frequency of association between deafness and cleft defects. A hearing conduction gap or more than 40 dB was most frequently present in complete cleft lip and palate (7/5,6%), followed by cleft palate (4/5%). Submucous cleft palate was observed to be less frequently accompanied by conduction deafness (9/56,2%) as compared to complete cleft palate, despite a common feature of bone and muscle support discontinuity. Cleft lip was least frequently accompanied by conduction deafness, but it was still present to a relatively high percentage when compared to the cleft-free population.

Prikazan je dezmoplastični fibrom tijela donje čeljusti u 58 godišnje bolesnice. Rijeđa pojava tumora u središnjim djelovima čeljusti, odsustvo specifičnih simptoma, samo klinički i rentgenološki nalaz ne osigurava preoperativno prepoznavanje tumora. Ispravna je dijagnoza moguća tek kada se ovi podaci upotpune makroskopskim i histološkim nalazom. Neprepoznavanje i zbog toga neodgovarajuće odstranjenje razlog su čestim recidivima dezmoplastičnog fibroma., The case report of a desmoplastic fibroma of the lower jaw in a 58 year-old female patient is presented. This tumor is often not preoperatively recognized because there are only clinical and X-ray findings, it is rare in the mid-part of the jaw and there are no specific symptoms. A correct diagnosis is made on the basis of macroscopic and histological findings. Desmoplastic fibromas frequently recur because they are not recognized and not enough of the tumor is surgically removed.