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In this paper, structural, elastic, electronic and magnetic properties of half-Heusler XSrC ([Formula: see text] and Na) compounds have been investigated utilizing full potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT). For exchange-correlation potentials, the generalized gradient approximation (GGA) has been used. The calculated cohesive and formation energy values showed that these compounds can be experimentally synthesized. The elastic properties were analyzed in detail and reveal that LiSrC and NaSrC compounds are mechanically stable. The spin-polarized band structure and density of states illustrate that LisrC and NaSrC alloys have a half metallic character. The total magnetic moment is 1[Formula: see text][Formula: see text] per formula unit that confirms the half metallic behavior and follows the Slater-Pauling rule [Formula: see text]. For half-Heusler XSrC ([Formula: see text] and Na) compounds, there are no available experimental or theoretical studies, our calculations are considered as first predictions.

We propose in the present work a Monte Carlo Simulation (MCS) of chemical reactions occurring in Plasma Enhanced Chemical Vapor Deposition (PECVD) reactor during the a-Si:H growth. From a microscopic view of chemical reactions, this MCS allowed to obtain macroscopic results. In gas phase, important reactions have been identified that contribute to the production of H, SiH2 and SiH3. We found that SiH4 →SiH2 + 2H is the dominant silane electron-impact dissociation. We found that the reaction SiH4 + H →SiH3 + H2 plays a central role in the production of SiH3 radicals. At the surface, the microscopic view allowed us to calculate site and surface reaction probabilities of SiH3 radicals. Results at macroscopic level were consistent with other works.

The aim of this work is to calculate the broadening of the spectral lines in a plasma constituted of electrons and V n + 22 ions (hydrogen-like Vanadium). In particular, we are interested in the contribution of weak collisions (free electrons–ions V n + 22 ) to this broadening. To this end, we place ourselves within the framework of the semi-classical theory using the electric dipole interaction. We also use the impact theory which is often adapted when dealing with the broadening of spectral lines by collisions of ions with electrons. The novelty in this work is based on the fact that the interaction (free electron- V n + 22 ) is of the Deutsch type which takes into account the quantum effects at short distance. We therefore used this interaction to calculate the collision cross section (free electron- V n + 22 ) in quantum mechanics on the one hand and in relativistic quantum mechanics on the other hand. We used the two cross-section expressions that we calculated to extract the amplitude of the collision operator. In using the first expression, we worked with the Maxwell distribution of velocities, while with the second expression of the cross section, we worked with the Juttner–Maxwell distribution of velocities. We also added to this work the effect of particles identity to calculate the amplitude of the collision operator, using the appropriate cross section. Comparisons with the results from Coulomb’s interaction have been made.

We investigate the ion effect on the broadening of the spectral line profile by the free electrons collisions with the emitters in plasmas. We only considered the weak collisions&rsquo, contribution. This effect has a consequence on the trajectories of the free electrons through the electric microfield created by the ions of the plasma. Thanks to the Meijer&rsquo, s functions, the calculation of the electronic Stark broadening is precisely established.

The instability of CH3NH3PbI3 perovskite hybrid organic–inorganic films is a serious problem, which might be a drawback for their use in solar energy conversion. In this work, we have evaluated the degradation of the perovskite films and studied the influence of film morphology on their degradation. CH3NH3PbI3 perovskite thin films were deposited on glass substrates by a spin coating technique at different centrifugation speeds using different solvents. This study aims to determine the films’ properties that may control the degradation process. This study was based on the comparison between the characteristics determined from XRD analysis and optical transmittance of freshly deposited films and those aged 1 year in ambient air at room temperature and dark conditions. The degradation was manifested by the partial decomposition of the perovskite to PbI2, I2, and metallic lead. The degradation evaluation was achieved by the determination of the variation of the most intense XRD diffraction peak in the freshly prepared film and after aging. The results indicated that the degradation is very sensitive to the films’ porosity and thickness. Reducing the thickness of the film or increasing the porosity enhances the degradation process.

Тонкі плівки використовуються в різних галузях промисловості, а саме у виробництві сонячних елементів, плоских екранів та для поліпшення фізичних властивостей поверхонь матеріалів. У процесах осадження тонких плівок ступінь рівноваги та інші характеристики плазми, такі як природа, густина і температура, повинні бути визначені, щоб зрозуміти появу різних явищ. У роботі основна увага приділяється вивченню просторових розподілів густин збуджених станів Ar* (3p54s (1sx: x = 2-5)), а також відносних внесків таких процесів, як бомбардування електронами, випромінювальне дезбудження, явища дифузії метастабільних станів та іонізація Пеннінга в популяції та депопуляції різних станів атомів аргону. Для цього радіаційну модель зіткнень (CRM), яка включала 41 стан, було застосовано з використанням заданих параметрів у плазмі високочастотного магнетронного розпилення. Ці параметри включають температуру електронів, густини електронів та іонів аргону. Кінетичні рівняння густин станів привели до матричної системи, яка була розв'язана чисельно за допомогою ітераційного методу Гауса-Зейделя. Результати показують, що осьові розподіли різних збуджених станів та станів на катоді трохи більші, ніж на аноді; вони також показують, що обидві густини менші, ніж у центрі реактора. Іонізація Пеннінга важлива для метастабільних станів 3p54s (1s5, 1s3), але не важлива для резонансних станів 3p54s (1s4, 1s2). Різні густини збуджених станів не є симетричними відносно центру реактора через наявність магнітного поля на катоді. Thin films are used in various industrial fields, namely in the manufacture of solar cells, flat screens and in improving the physical properties of material surfaces. In thin film deposition processes, the degree of equilibrium and other plasma characteristics such as the nature, density and temperature must be identified in order to understand the occurrence of various phenomena. In this work, the main focus is on studying the spatial distributions of densities of excited states of Ar* (3p54s (1sx: x = 2-5)), as well as the relative contributions of processes such as the electron impact effect, the radiative de-excitation, the diffusion phenomena of metastable states and the Penning ionization in the population and depopulation of different argon atoms states. For this purpose, a Collisional-Radiative Model (CRM) including 41 states was applied using specified parameters in RF magnetron sputtering plasma. These parameters include electron temperature, electron and ion densities of argon. The rate equations of the state densities led to a matrix system that was solved numerically by iterative Gauss-Seidel Method. The results show that the axial distributions of different excited states and those on the cathode side are slightly larger than those found on the anode side, and they show also that both densities are less than at the reactor center. For metastable states 3p54s (1s5, 1s3), the Penning ionization is important, but it is not important for resonant states 3p54s (1s4, 1s2). Different densities of the excited states are not symmetrical with respect to the center of the reactor due to the existence of a magnetic field at the cathode.

In this paper, we present the study of the structural, mechanical, magneto-electronic and thermodynamic properties of the perovskite KBeO3. The calculations were performed by the full potential augmented plane wave method, implemented in the WIEN2k code which is based on density functional theory, using generalized gradient approximation. The computed formation energy and elastic constants indicate the synthesizability and mechanical stability of KBeO3. Moreover, our results showed that the latter is a half-metallic material with half-metallic gap of 0.67 eV and an integer magnetic moment of 3μB per unit cell. In addition, KBeO3 maintains the half-metallic character under the pressure up to about 97 GPa corresponding to the predicted magnetic-phase transition pressure from ferromagnetic to non-magnetic state. The volume ratio V/V0, bulk modulus, heat capacity, thermal expansion and the Debye temperature are analyzed using the quasi-harmonic Debye model.

We present in this work a new simple estimation of Stark broadening of neutral atoms in plasmas. This is achieved by exploiting the S-matrix unitarity criteria to get a more precise estimation of the minimum of the impact parameter. The latter depends on a critical velocity of the free electrons. The result is: the collision operator is the sum of two contributions; the first is from electrons velocities less than the critical velocity (slow electrons), and the second is from electrons with velocities greater than the critical velocity (fast electrons). When the reduced critical velocity is very small ( v c ≪ 1 ), it is shown that the strong collision contribution can be expressed by Meijer G-functions. This corresponds to high energy ionization element in stellar plasmas. Then we applied our theoretical results to a plasma consisting of magnesium. We find a good agreement with experimental and with others theoretical results for a range of electron densities and temperatures.

This paper is based on the study of the emitted radiation by electrical discharge plasma, caused in the helium a pressure of 4.8 Torr, a power MW of 108W. The study numerical model allows the identification of several spectral lines. With the Boltzmann method the study have calculated the electronic temperature (Te=3.23eV), it corresponds to the classification scale of plasmas. The application of the Saha law gives the electronic density of the electrical discharge plasma (Ne=3.67 10 13 cm-3). The calculated theoretical spectra are in good agreement with the experimental ones. Key words: Discharge plasma, broadening, shape of spectral line, thermodynamic equilibrium.

This work presents a Monte Carlo Simulation (MCS) of chemical reactions that occur in the volume of a PECVD reactor during deposition of a-C:H thin film elaborated from (CH 4/H 2) mixture. Besides CH 4 and H 2, molecules and radicals taken in account in this study are CH 3, CH 2, CH, C2H5, C2H6 and H. The MCS is based on binary collisions. MCS allowed us to obtain the densities and the molecular fractions of different particles and other parameters related to reaction rates. The results are in good agreement with other works.

Sediments were collected at 33 stations from Algiers Bay to determine potential sources of pollution. The analyses were made with Phillips X-ray fluorescence (XRF) equipment. The results give information about the level of concentrations for La, Ce, Er and Tb. Except for lanthanum and erbium which present a particular distribution (unrelated to the sedimentary facies), the distribution of the different rare earth metals is irregular and depends on the bay morphology. Terbium, erbium and cerium present high concentrations in the vases. The level of pollution by rare earth metals of the botton sediments in Algiers Bay has been shown to be significant compared with that of Surkouf, considered to be a region with low anthropogenic activity

Cette etude est consacree a l'etude de la spectroscopie de plasmas de decharge lors de deposition sur couches minces par une pulverisation cathodique magnetron RF. La chambre de pulverisation contient une cible en Nylon 6,6 (Good fellow). L’etude concerne les transitions electroniques d’atomes et d'ions d’argon, des molecules d’azote et d'ions d’azote dans des plasmas et la determination de la temperature electronique et de la densite electronique de ce plasma. Les caracterisations de plasma montrent que le plasma de decharge est hors equilibre thermodynamique local. Les resultats de notre calcul sont en adequation avec les resultats experimentaux de J. Kousal et al. (2009) [1].

In this paper, a number of polymeric waveguide structures have been analyzed by using two distinct techniques which are: effective index method (EIM) and numerical simulation based on finite difference method (FDM). The main aim of this investigation is the calculation of effective indexes (EI) of the following structures: rib, ridge and buried channel waveguides at telecom wavelength $$\lambda =1.55\,\upmu \hbox {m}$$ for different dimensions of waveguide cores varying from 1.5–4 $$\upmu \hbox {m}$$ . Moreover, other optical propagation characteristics such as: confinement factor, normalized and propagation constant have been studied in TE polarisation. Otherwise the effect of the structure parameters and dimensions on the dispersion characteristics has been investigated. On the other hand, the optical field distribution has been computed using commercial software named OlympIOs. The polymers applied in the design of waveguide structures are the PVCi (n = 1,562 $$\lambda = {1.55}\,\upmu $$ m) used as core layer and the PMATRIFE (n = 1,409 $$\lambda = 1.55\,\upmu $$ m) used as substrate or cladding layer. The results obtained using EIM and simulation based on FDM show that effective index and field confinement factor of TE fundamental mode increase monotonously with the increasing dimension of core. The obtained results are in good agreement with published data based on other numerical methods.

In this work, we have measured the selenium content in wheat produced locally in eight different regions of Algeria from east to west, and we have established the annual consumption of selenium for five socio-professional categories. Instrumental neutron activation analysis is used. The selenium levels in wheat samples varied from 21 (Tiaret) to 153 μg/kg (Khroub), with a mean value about 52 μg/kg. The mean of selenium daily consumption from ingestion of wheat per person in the eight regions varied from 32 to 52 μg/day which is close to the minimal FAO recommendation.

The high orders of Stark effects on spectral line shapes are examined in the ion-static and electron-impact ap-proximations. At first the distribution functions of the spatial derivative of the ion microfield in He+ plasma are calculated for different plasma conditions when the coupling parameter is weak. We present new results about the spatial derivative ion microfield distributions and apply them to show the asymmetry of the Lyman-α (Ly-α) line in He+ plasma. At the second stage we show that asymmetry is affected by the spatial derivative tensor of the local ion electric field. We have used the Monte-Carlo simulation (MCS) to compute the distribution functions for all tensor components and use them to solve the evolution equation of emitter whose solution serves to compute and therefore to show the line shape asymmetry. Good agreement of our distribution functions of ion microfield gradients and the line asymmetry with other results are obtained (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Vector transmitted diseases are often a serious threat for child health, especially for children traveller in tropical regions. Few arthropod borne diseases are preventable by immunization or chimioprophylaxis. Prevention of most of them is based on personal protection against arthropod bites. The evidence of its efficacy has been established by the use of impregnated bed nets, impregnated clothes with permethrin or mosquito repellent which reduced significantly child malaria morbidity and mortality in endemic countries. These personal protective measures are able to minimize arthropod bites and prevent Chikungunya infection, dengue fever and Lyme disease. The choice of a repellent among the commercialised products need to be efficacy and safety evidence based. This article propose to raise this issue and to give pragmatic recommendations, with a focus to children below 30 months who are at a high toxicological risk. Severity of these diseases allowed to use potentially toxic repellents if misused.

Each year, half a million of children leave France to travel towards countries south or east of the European Union, sometimes in poor sanitary conditions. In order to propose essential or useful immunizations for these trips, the current synthesis will allow the practitioner to insure that the routine French immunization schedule has been followed, and to complete it if needed, to protect the child according to the epidemiological situation in the visited area, to try to reduce the limitations of the immunization of the traveler child. In case of emergency, or close departure, it may be useful to follow an accelerated schedule of the last minute, and, sometimes, to immunize traveler children with a chronic disease. Informations on Internet sites useful for the knowledge of current infectious risks in the destination country are also provided.

We present our numerical calculations of dielectronic recombination rate coefficients which are spin dependent (2lnl-1snl 1 L, 1snl 3 L) and develop scaling relations which are converging for all spin (S), angular (L) and main (n) quantum numbers. The influence of atomic data inaccuracies, spin dependent channelling of dielectronic recombination rates and collisions on the atomic/ionic fractions is discussed.

In this paper the results of Lyman- α line shapes without fine structure are rederived using a path integral formalism. The method presented here is designed to provide a quantum formalism that will treat the ions and the electrons on the same physical basis. This method also has the advantage of treating cases where the dynamical effects are present. We therefore give an expression of the dipolar autocorrelation function taking into account the ion dynamics effects. At the end, some Lyman- α lines are plotted under several conditions and compared to those obtained by other methods. This comparison checks out the validity of our approach. Note here that we do not intend to show a new result in spectral line shapes but add a contribution to the path integral formalism.

A calculation of film surface temperature during thin films growth by sputtering technique is proposed. The calculation procedure is based on the conversion into heat of the total flux energy of species impinging the film surface during growth. The results indicate that the film's surface temperature depends drastically on material substrate thermal conductivity and thickness on one hand, and the plasma conditions namely the discharge power on the other. The predicted film surface temperatures were used to explain the microstructure evolution of hydrogenated amorphous silicon (a-Si:H) thin films deposited by reactive radio frequency (RF) sputtering on different substrates.

Background. - Outcone of patients with retinoblastoma is strongly related to the extent of the disease at diagnosis. Thus, prognosis of extra-ocular retinoblastoma is poor and metastases to central nervous system are usually fatal. Case report. - An 8-year-old child presented with a lose recurrence of bilateral retinoblastoma. Initial treatment had associated enuclation of the left eye and radiation therapy on the right. At time of tumour recurrence, clinical examination showed cervical lymph nodes. There was a large frontal metastasis on the CT scan and bone marrow examination showed a minimal involvement by malignant cells. The patient achieved complete remission with high dose etopiside and carboplatin; he subsequently underwent massive chemotherapy followed by bone marrow rescue, and received additional radiation therapy on the frontal and cervical areas. He is well, five years after relapse. Conclusion. - This case highlights efficacy of chemotherapy in advanced retinoblastomas, intensive chemotherapy is a promising and potentially curative approach in the management of advanced or metastatic retiboblastomas.

BACKGROUND Microscopic extrascleral involvement and involvement of optic nerve resection line are accepted risk factors for orbital and/or metastatic disease from retinoblastoma. Conversely, choroidal and retrolaminar optic nerve involvement are questionable risk factors. The aim of this retrospective study was to define the histopathologic risk factors for orbital and/or metastatic disease in patients treated by first-line enucleation. METHODS Histopathologic review of 172 evaluable patients treated at Institut Curie between 1977 and 1990 determined the degree of choroidal (minimal or massive), scleral (intra- or extrascleral), optic nerve (prelaminar, retrolaminar with or without resection line involvement), and anterior chamber invasion. The degree of differentiation was also analyzed. The log rank test was used for univariate analysis and the Cox regression model was used for multivariate analysis. RESULTS Eighty-seven percent of the 172 patients were disease free at 3 years. Twenty-three patients developed retinoblastoma recurrence. The disease-free survival was significantly different among the five subgroups of choroidal or scleral invasion (P = 3 × 10−3). The differences among the four subgroups of optic nerve invasion were also significant (P = 10−4). Classical factors were confirmed in our series (extrascleral involvement and involvement of optic nerve resection line). Multivariate analysis of the 149 patients without these classical risk factors revealed two factors that increase the risk of orbital and/or metastatic disease: massive choroidal invasion and postlaminar optic nerve involvement. CONCLUSIONS In our experience, retrolaminar optic nerve involvement, with free resection line, and massive choroidal invasion significantly increase the risk for orbital and/or metastatic disease. Cancer 1997;77:1206-13.

Ti–Ni films with thicknesses of 2 and 8 μm were deposited at 823 K onto Si substrates. Internal friction measurements using frequencies near 2 kHz were performed during heating and cooling cycles between 223 and 393 K. Upon heating, we observe two loss peaks that can be correlated with the martensite ( M )→ R phase → austenite ( A ) phase transformations. Upon cooling, only one peak related to the A→R transformation is observed. The height of the loss peak for the M→R transformation increases with decreasing film thickness. In contrast, the height of the RA peak decreases. In conjunction with the internal friction measurements, the stress evolution during heating and cooling was examined using the wafer curvature method. The stress in the films due to phase transformations and thermal misfit between film and substrate increases with decreasing film thickness. It can be shown that the behaviour of the martensitic transformation depends on the constraint imposed by the substrate and on film thickness.

Vector transmitted diseases are often a serious threat for child health, especially for children traveller in tropical regions. Few arthropod borne diseases are preventable by immunization or chimioprophylaxis. Prevention of most of them is based on personal protection against arthropod bites. The evidence of its efficacy has been established by the use of impregnated bed nets, impregnated clothes with permethrin or mosquito repellent which reduced significantly child malaria morbidity and mortality in endemic countries. These personal protective measures are able to minimize arthropod bites and prevent Chikungunya infection, dengue fever and Lyme disease. The choice of a repellent among the commercialised products need to be efficacy and safety evidence based. This article propose to raise this issue and to give pragmatic recommendations, with a focus to children below 30 months who are at a high toxicological risk. Severity of these diseases allowed to use potentially toxic repellents if misused.

Each year, half a million of children leave France to travel towards countries south or east of the European Union, sometimes in poor sanitary conditions. In order to propose essential or useful immunizations for these trips, the current synthesis will allow the practitioner to insure that the routine French immunization schedule has been followed, and to complete it if needed, to protect the child according to the epidemiological situation in the visited area, to try to reduce the limitations of the immunization of the traveler child. In case of emergency, or close departure, it may be useful to follow an accelerated schedule of the last minute, and, sometimes, to immunize traveler children with a chronic disease. Informations on Internet sites useful for the knowledge of current infectious risks in the destination country are also provided.

International audience; The autocorrelation function for the velocity and for the electric microfield of an impurity ion in a Two Ionic Component Plasma (TICP) is considered. A simple model is constructed for this purpose that preserves the exact short time dynamics and the long time global constraint of a given self-diffusion coefficient. The memory function and then the collision effects associated with the correlation function for the self-diffusion are expressed in terms of an effective two body interaction via a screened effective potential. The basic approximation used in our approach is the "disconnected" one that refers to the collision operator. A comparison of the prediction of this model for the self-diffusion and for the autocorrelation functions with the results of the molecular dynamics simulation developed in our laboratory (PIIM) shows an acceptable agreement over a wide range of plasma coupling, impurity ion charge and concentration.

The martensitic transformation of Ti–Ni shape memory alloys is very sensitive to thermomechanical treatments (cold work and annealings). In the present paper, a Ti–Ni alloy close to the equiatomic composition has been 40% cold rolled and then submitted to various annealing treatments, each one characterized by temperature and time (Ta, ta). A large range of annealing temperatures (538–778 K) and times (10 s–123 d) has been covered. From differential scanning calorimetry measurements, three zones have been identified with reference to (Ta, ta) values. Zone I, at low temperatures and times, is characterized by badly defined transformations on cooling as well as on heating; it corresponds to a recovery–reverse martensitic transformation stage. Zone II exhibits large changes of the transformation features which occur in two steps on cooling (R phase then martensitic) and in one step on heating; this zone corresponds to the recrystallization and growth of very small stressed grains. Similar transformation behavior can be obtained with different (Ta, ta) annealings, which can be characterized by an activation energy of ≈3.4 eV in the range 698–778 K. Zone III relates to a well defined martensitic transformation taking place in one step with almost no further evolution; it corresponds to the growth of stress-free grains.

The absorption phenomena is very important effect in optically thick plasmas. It is expressed by the radiative transfer which analyses interactions of the radiation field with the plasma. We present a model using a global absorption coefficient which takes in to account this effect and shows its dependence with the optical length of the plasma. The inhomogeneity of the medium has an effect influencing the redistribution of radiation in optically thick plasmas. Our results in lithium-like aluminum are in good agreement with experimental spectra.

Outcome of patients with retinoblastoma is strongly related to the extent of the disease at diagnosis. Thus, prognosis of extra-ocular retinoblastoma is poor and metastases to central nervous system are usually fatal.An 8-year-old child presented with a late recurrence of bilateral retinoblastoma. Initial treatment had associated enuclation of the left eye and radiation therapy on the right. At time of tumour recurrence, clinical examination showed cervical lymph nodes. There was a large frontal metastasis on the CT scan and bone marrow examination showed a minimal involvement by malignant cells. The patient achieved complete remission with high dose etoposide and carboplatin; he subsequently underwent massive chemotherapy followed by bone marrow rescue, and received additional radiation therapy on the frontal and cervical areas. He is well, five years after relapse.This case highlights efficacy of chemotherapy in advanced retinoblastomas. Intensive chemotherapy is a promising and potentially curative approach in the management of advanced or metastatic retinoblastomas.

Microscopic extrascleral involvement and involvement of optic nerve resection line are accepted risk factors for orbital and/or metastatic disease from retinoblastoma. Conversely, choroidal and retrolaminar optic nerve involvement are questionable risk factors. The aim of this retrospective study was to define the histopathologic risk factors for orbital and/or metastatic disease in patients treated by first-line enucleation.Histopathologic review of 172 evaluable patients treated at Institut Curie between 1977 and 1990 determined the degree of choroidal (minimal or massive), scleral (intra- or extrascleral), optic nerve (prelaminar, retrolaminar with or without resection line involvement), and anterior chamber invasion. The degree of differentiation was also analyzed. The log rank test was used for univariate analysis and the Cox regression model was used for multivariate analysis. RESULTS. Eighty-seven percent of the 172 patients were disease free at 3 years. Twenty-three patients developed retinoblastoma recurrence. The disease-free survival was significantly different among the five subgroups of choroidal or scleral invasion (P = 3 x 10(-3). The differences among the four subgroups of optic nerve invasion were also significant (P = 10(-4)). Classical factors were confirmed in our series (extrascleral involvement and involvement of optic nerve resection line). Multivariate analysis of the 149 patients without these classical risk factors revealed two factors that increase the risk of orbital and/or metastatic disease: massive choroidal invasion and postlaminar optic nerve involvement.In our experience, retrolaminar optic nerve involvement, with free resection line, and massive choroidal invasion significantly increase the risk for orbital and/or metastatic disease.

Orbital involvement is a rare occurrence in retinoblastoma but still carries a bad prognosis. The aim of this study was to define more clearly the role of chemotherapy in this advanced disease.Between 1977 and 1991, 33 patients were treated at the Services de Pédiatrie at Institut Curie (Paris, France) for orbital involvement of retinoblastoma, which was isolated in 20 patients and associated with metastases in 13 patients (outside the central nervous system [CNS], 6; within the CNS, 7). Treatment included chemotherapy for 33 patients, irradiation of the orbit for 23 patients, and intrathecal chemotherapy and/or CNS irradiation in selected patients.The plateau phase of the survival curve was reached at 15 months, with a survival of 34% plus or minus 8%. The disease free interval was longer when patients had no CNS disease (P0.05). Twenty of the 21 recurrences (95%) occurred within 1 year after diagnosis of orbital involvement.Intensive chemotherapy using cyclophosphamide, platinum compounds, epipodophyllotoxins, doxorubicin, and vincristine was effective in orbital involvement of retinoblastoma even with associated extra-CNS metastases. However, associated CNS disease still carries a bad prognosis, and long term follow-up is necessary to evaluate the risk of a second tumor.

The present paper deals with the investigation of Argon ions – substrate interactions during film growth and their influence on sputtered hydrogenated amorphous silicon (a-Si:H) thin films structural properties. These interactions are characterized by mean of the calculation of the energy distribution of Ar ions striking the substrate and their striking force measurement in the case of Rf diode sputtering. The influence of the Ar ions bombardment on structural and physical properties of amorphous silicon thin properties is discussed. The ion bombardment affects the film growth processes and consequently, it causes films densification and evolution of film microstructure from amorphous state at low power towards a microcrystalline material with increasing the Rf power.

A model for calculating the profile of spectral lines emitted by multielectron emitters in a hot plasma is described. The Stark broadening is included in the model by using the static ion approximation and an impact approximation for the electrons. The atomic data required for the line-shape calculation are extracted from an atomic structure code and prepared as data necessary for the excited and ground levels of the radiative transition. For the cases where electron broadening is much smaller than the average ionic Stark shift, an approximation is proposed to obtain rapidly a diagonal form of the evolution operator for the emitter. Line shapes of lithiumlike and berylliumlike ions have been calculated under the conditions of recent experiments performed in laser-produced plasmas.

The broadening of x‐ray spectral lines has become an established diagnostic of Ne in high‐density plasmas, particularly those of interest in inertial confinement fusion (ICF). Work to date has concentrated mostly on the broadening of K‐shell lines in moderate Z (Z∼10–20) ions in plasmas with electron densities up to 1024 cm−3. In this paper we report on calculations of line broadening for Ne‐like Xe (Xe44+) appropriate for diagnosis of higher density plasmas with Ne∼1025 cm−3. These calculations have been performed with a recently developed state of the art computer code which treats the ion and electron broadening in the quasi‐static and impact approximations, respectively. In this paper, we summarize recent work examining the behavior of the width of the Ne‐like Xe 3–2 and 4–2 transitions with electron density. The broadening of the 1s–3p line in H‐like Ar and the 1s2–1s3p transition in He‐like Ar is also studied in order to benchmark the code used in the calculations.