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Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p

Introduction Gastroesophageal reflux disease is a common condition in pediatric age group. Many surgeons believe that complete fundoplication provides better reflux control, yet it results in more dysphagia and gas-bloat symptoms. On the other hand, a partial wrap is reported to have fewer adverse effects but a higher failure rate in controlling reflux. Until now, there is no agreement and little evidence as to whether complete or partial fundoplication is the optimal procedure in this age group. Patients and methods This is a prospective singleblinded randomized comparative study that included 30 patients who were admitted in the time period from May 2013 to May 2015 and were treated laparoscopically byeither Nissen or Thal fundoplication. Results Operative time (minutes) was significantly longer in the Thal group (186 ± 52) when compared with the Nissen group (150 ±48) (P =0.031). Intraoperative complications showed no significant difference when comparing the two groups. Although the incidence of postoperative dysphagia was statistically insignificant, the duration of dysphagia did show significantly shorter duration in the Thal group (median: 6 days), when compared with the Nissen group (median: 17 days). There was no recurrence in the Thal group, whereas there was one recurrence in the Nissen group. Conclusion This study suggests that Thal fundoplication offers an effective alternative to Nissen fundoplication with apparently shorter duration of dysphagia and thus earlier return to the normal eating pattern. Level of evidence

Background Tension gastrothorax develops when the stomach, herniated through a congenital diaphragmatic defect into the thorax, is massively distended by trapped air. We report a case of tension gastrothorax and review the literature. Case Report A previously healthy 8-month-old female presented with severe respiratory distress, misdiagnosed as tension pneumothorax. Intercostal tube was inserted. The tube was noted to drain food as well as air. The patient was investigated by radio-contrast swallow, which demonstrated the presence of the stomach in the chest. The patient was operated upon, and the stomach, transverse colon, and spleen were reduced back to the abdomen. The defects in the stomach and diaphragm were closed. Conclusion Tension gastrothorax is a life-threatening condition leading to acute and severe respiratory distress. The presence of air-filled structure in left hemithorax in a previously healthy child presenting with acute respiratory distress should prompt the inclusion of tension gastrothorax in the differential diagnosis.

Background/purpose Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is the most common cause of persistent hypoglycemia in infancy with consequences such as seizures and brain damage. Treatment that prevents the occurrence of these sequele is essential. When medical therapy fails or complications are anticipated, early pancreatectomy is recommended to maintain euglycemia. The aim of this study was short-term evaluation of near-total pancreatectomy for PHHI after failure of medical treatment in patients in Mansoura, Egypt. Patients and methods During May 2002 to May 2010, 33 patients suffering from persistent hyperinsulinemic hypoglycemia were admitted to Mansoura university child hospital. Twenty patients responded to medical treatment and 13 patients (eight girls and five boys) were treated by near-total (90–95%) pancreatectomy after failure of medical treatment. Their ages at the time of surgery ranged from 20 days to 27 months. Only patients who were surgically managed were included in this study. All of them suffered from symptoms of PHHI: thermoregulatory problems in five cases, tremors in five cases, seizures in three, irritability in five, respiratory distress in eight, apnea in four, hypotonia in four, lethargy in five, and feeding difficulty in four cases. All cases were diagnosed following strict criteria that included bouts of hypoglycemia without acidosis coinciding with increased insulin level. Follow-up ranged from 3 months to 8 years. Results Primary success occurred in two cases (15%); four more cases (31%) developed temporary diabetes mellitus, and one case (8%) had a temporary pancreatic fistula. Eventually, total cure occurred in seven cases (54%); six cases (46%) developed a variety of complications; and persistent hypoglycemia was seen in two. Persistent diabetes mellitus was observed in three patients, developmental delay in one, and persistent neurological deficit in two patients; there was one case of mortality. Conclusion Near-total (90–95%) pancreatectomy is a suitable procedure for treatment of nesidioblastosis not responding to medical treatment and should be performed as early as possible. Keywords : Mansoura, near-total pancreatectomy, persistent hyperinsulinemic hypoglycemia

Background/purpose Congenital adrenal hyperplasia is a common cause of ambiguous genitalia in female individuals. These patients require feminizing surgery aiming at reconstruction of feminine external genitalia with normal function. Total urogenital mobilization was developed to avoid dissection in the common wall between the vagina and urethra. This study aims at evaluating the outcome of feminizing genitoplasty after the use of urogenital mobilization. Patient and methods Fourteen female patients with congenital adrenal hyperplasia were managed during the period from July 2007 to April 2011. They were assessed clinically according to the Prader score. The common channel anatomy was studied by a flush retrograde genitogram. Clitoroplasty, vaginoplasty, and labioplasty were performed. The common sinus was managed by urogenital mobilization. Postoperative cosmetic outcome was evaluated according to the criteria described by Creighton and colleagues. Follow-up included clinical assessment of the urethral and vaginal openings and clinical evaluation of the continence for urine. Results A genitogram has a sensitivity of 64.3% in estimating the length of the common channel. The length of common channel is not related to the degree of virilization. Good cosmetic outcome was reported in 71.4% of cases. All postoperative complications were minor and managed by simple maneuvers. All patients had good urinary control after urogenital mobilization. Conclusion Urogenital sinus mobilization is a valuable tool in the early one-stage feminizing surgery with few technical problems, good cosmetic outcome, low incidence of complications, and good urinary continence. Keywords : congenital adrenal hyperplasia, feminizing genitoplasty, urogenital sinus mobilization

Constant temperature molecular dynamics simulations have been performed on ZnS at different temperatures ranging from 300 K to 1400 K with the objective of establishing and validating the temperature dependent structural and thermodynamic properties. The simulations were carried out in canonical ensemble (NVT) using Lennard‐Jones pair potential. Radial distribution functions have been calculated. RDF peaks are found to be broadened and decrease in heights with increasing temperature, reflecting enhanced atomic motions. Energy temperature graph does not show any break, however a break in the specific heat curve and a λ type transformation are observed indicating second order phase transformation. Mean Square Displacement (MSD) for Zn and S atoms separately have been measured and almost identical graph were obtained. The MSD curve exhibits the existence of maximum disorderness at 1100 K and 1400 K which indicates phase transformations around them.

I discuss how effective theories and numerical simulations of Quantum Chromodynamics are together helping us understand the interaction between neutrons and protons. Explicit numerical evaluation of the QCD path integral, using lattice methods and super‐computers, appears to be the best option for calculations of QCD in the non‐perturbative regime. I show that complementary information is provided by effective theories, which can help to relate these intensive “lattice QCD” calculations to nuclear‐physics experiments. I place particular emphasis on the way in which the long‐distance symmetries of QCD observed in lattice simulations constrain the interactions of neutrons and protons with one another, and I show how this leads to predictions for electron scattering from light nuclei.

An artificial‐neural‐network (ANN) model was developed to estimate the crystalline size of ZnO nanopowder as a function on the planetary milling parameters such as balls to powder ratio and rotation speed. This nanopowder was synthesized by mechanical milling and the required data for training were collected from the experimental results. The synthesized ZnO nanoparticles are characterized by X‐ray diffraction (XRD). It was found that artificial neural network was very effective providing a perfect agreement between the outcomes of ANN modeling and experimental results. An optimization model is then developed to find the best milling parameters (rotation speed and balls to powder ratio) producing the minimal average crystalline size.

A new variational impact parameter approach to the process of direct electronic excitation of atoms by impact of ions at intermediate velocities regimes was shown to be very successful in predicting the saturation of cross sections when the projectile charge is increased [1–4]. In our approach, this new procedure is based on the fractional form of the Schwinger variational principle and applied to study K‐shell excitation of Ca18+ (1s2) ions impinging at 8.6 MeV/amu on various gases (H2, He, N2, O2, Ne, Ar, Kr, Xe). The excitation cross sections are compared with another theoretical approaches, like Born approximation. All obtained results stay in good agreement with experimental data of Xiang‐Yuan Xu et al. [5].

We apply Tsallis’s q‐indexed nonextensive entropy to formulate a random matrix theory (RMT), which may be suitable for systems with mixed regular‐chaotic dynamics. We consider the super‐extensive regime of q

The potential energy curves of the ground state and many excited states of the RbAr van der Waals complex have been determined using [Rb+] and [e‐Ar] pseudopotentials with the inclusion of core polarization operators on both atoms. This has reduced the number of active electrons of the RbAr system to only one valence electron, permitting the use of large basis sets for both the Rb and Ar atoms. Potential energy curves of the ground state and many excited states have been calculated at the SCF level. The core‐core interactions for Rb+Ar are included using the accurate CCSD potential of Hickling et al [Hickling, H.; Viehland, L.; Shepherd, D.; Soldan, P.; Lee, E.; Wright, T. Phys. Chem. Chem. Phys. 2004, 6, 4233]. Spectroscopic constants for the ground and excited states of RbAr are derived and compared with the available theoretical and experimental results. Furthermore, we have predicted the X2Σ+‐A2Π1/2, X2Σ+‐AΠ3/2 and X2Σ+‐B2Σ1/2+ absorption spectra.The potential energy curves of the ground state and many excited states of the RbAr van der Waals complex have been determined using [Rb+] and [e‐Ar] pseudopotentials with the inclusion of core polarization operators on both atoms. This has reduced the number of active electrons of the RbAr system to only one valence electron, permitting the use of large basis sets for both the Rb and Ar atoms. Potential energy curves of the ground state and many excited states have been calculated at the SCF level. The core‐core interactions for Rb+Ar are included using the accurate CCSD potential of Hickling et al [Hickling, H.; Viehland, L.; Shepherd, D.; Soldan, P.; Lee, E.; Wright, T. Phys. Chem. Chem. Phys. 2004, 6, 4233]. Spectroscopic constants for the ground and excited states of RbAr are derived and compared with the available theoretical and experimental results. Furthermore, we have predicted the X2Σ+‐A2Π1/2, X2Σ+‐AΠ3/2 and X2Σ+‐B2Σ1/2+ absorption spectra.

金沢大学設計製造技術研究所 / 金沢大学理工研究域電子情報通信学系, Nanocrystalline silicon (ns-Si) thin films deposited through plasma-enhanced chemical vapor deposition technique were studied. These films were grown at low deposition temperature of 200°C and at different silane flow rates ([SiH4]). Characterization of these films with Raman spectroscopy, x-ray diffraction and atomic force microscopy revealed that no films deposited at [SiH4]=0.0sccm. In addition, the structural change from an amorphous to a nanocrystalline phase at [SiH4]=0.2sccm. The Fourier transform infrared spectroscopic analysis showed at low values of [SiH4](0.1sccm), no hydrogen incorporated in the nc-Si thin film. However, the intensity of the spectra around 2100 cm-1 is likely to decreases with increasing [SiH4]. We have observed photoluminescence (PL) at room temperature in the range of 1.7 eV to 2.4 eV for all the films. Presence of the very small crystallites (the size less than 20 nm) responsible for quantum confinement effect. Variations of the PL intensity, width and position are well correlation with the structural properties of the films such as crystalline size, crystalline volume fraction, and hydrogen content. Furthermore, the PL emissions also showed correlation with the distribution of spherical grains with the size below 50 nm distributed on the films surface. © 2011 American Institute of Physics., Conference Paper

The present work deals with the particle size effect on the electrical properties in Neodymium Cobaltate‐Manganites System. Neodymium Cobaltate materials could be used as hydrogen storage materials. Nd0.6Sr0.4MnxCo1‐xO3; (x = 0, 0.3, 0.7 and 1 ) were prepared using co‐precipitation method from the initial pure chlorides of neodymium, strontium cobalt and manganese to react with pure sodium hydroxide with the proper molar ratio. The synthesized composites were studied in details in terms of their morphological and structural properties. The energy dispersive spectroscopy EDS reveals that the synthesized composites are in proper stoichiometry of the proposed structure. The obtained powder was pressed as disc at 2 T pressure are fired at different temperatures; 650°C, 750°C and 850°C. It was fired for 12h in each temperature. The X‐ray analysis exhibited that crystal structure for all composites are the same and possessing single phase with orthorhombic crystal system of space group pnma (62). The DC resistivity as a function of temperature was measured in the range from room temperature up to 200° C.The present work deals with the particle size effect on the electrical properties in Neodymium Cobaltate‐Manganites System. Neodymium Cobaltate materials could be used as hydrogen storage materials. Nd0.6Sr0.4MnxCo1‐xO3; (x = 0, 0.3, 0.7 and 1 ) were prepared using co‐precipitation method from the initial pure chlorides of neodymium, strontium cobalt and manganese to react with pure sodium hydroxide with the proper molar ratio. The synthesized composites were studied in details in terms of their morphological and structural properties. The energy dispersive spectroscopy EDS reveals that the synthesized composites are in proper stoichiometry of the proposed structure. The obtained powder was pressed as disc at 2 T pressure are fired at different temperatures; 650°C, 750°C and 850°C. It was fired for 12h in each temperature. The X‐ray analysis exhibited that crystal structure for all composites are the same and possessing single phase with orthorhombic crystal system of space group pnma (62). The DC resisti...

A microscopic folding approach based upon the effective M3Y nucleon-nucleon interaction and the nuclear matter densities of the interacting nuclei has been carried out to explain recently measured experimental data of the {sup 6}He+{sup 120}Sn elastic scattering reaction at four different laboratory energies near the Coulomb barrier. The corresponding reaction cross sections are also considered.

The adiabatic potential energy curves and the spectroscopic constants of the ground state and many excited states of 1Σ+ symmetry for the alkaline earth ion BeLi+ have been investigated. We have used an ab initio approach based on non‐empirical pseudopotentials for the Be2+ and Li+ cores, parametrized l‐dependent polarization potentials and full configuration interaction calculations. The ground state spectroscopic constants are in good agreement with the available theoretical results; whereas these spectroscopic properties for the excited states are presented for the first time. Moreover, numerous avoided crossings between electronic states of 1Σ+ symmety have been localised and analysed. They are related to the interaction between the electronic states and to the charge transfer process between the two ionic systems Be+Li and BeLi+. Furthermore, the permanent and transition dipole moments are determined for a wide interval of internuclear distances. The permanent dipole moments for the X(1)1Σ+ and 31Σ+ ...

Absolute cross sections for electron impact dissociative excitation and ionization of ions of interest in thermonuclear fusion are reported for energies ranging from the respective reaction thresholds up to 2.5 keV. The animated crossed‐beams method is used. Results have been measured both for heavy targets like the methane family CDn+(n = 1–4) and for light targets like H2+, D2+, D3+ and D2H+. Kinetic energy release distributions are deduced from the analysis of ionic product velocity distributions obtained for each ionic fragment, at selected electron energies. The comparison of the present energy thresholds and kinetic energy release with available published data allows the identification of initial or intermediate states contributing to the observed processes. Individual contributions for dissociative excitation and dissociative ionization are determined for each singly‐charged product, which are of significant interest in fusion plasma applications. Present experimental data for electron impact dissociative excitation and ionization processes are represented by three‐parameter analytic fitting functions appropriate for plasma modeling. Isotope ratios are estimated in the study of the D2H+ target to check for isotope effects.

This paper reports a facile hydrothermal synthesis of Sb‐doped ZnO nanoneedles by using aqueous mixtures of zinc chloride, antimony (Sb) chloride, hexamethylenetetramine (HMTA) and ammonium hydroxide at low temperature of 110 °C. The morphological characterizations of as‐synthesized nanoneedles were done by field emission scanning electron microscopy (FESEM) which reveals that the nanoneedles are grown in large‐quantity and arranged in such a special manner that they made flower‐like morphologies. The structural characterization of as‐synthesized nanoneedles was investigated by X‐ray diffraction (XRD) pattern which confirm the well‐crystalline and wurtzite hexagonal phase of as‐synthesized products. The compositional characterization of as‐synthesized nanoneedles was characterized by energy dispersive spectroscopy (EDS), which verify that the synthesized nanoneedles are composed of zinc, Sb and oxygen. For application point of view, the synthesized nanoneedles were used as photocatalyst for photocatalytic...

Nano particles of Ni1−xMgxFe2O4 (x = 0.0, 0.25, 0.5, 0.75, 1) have been prepared by the co‐precipitation chemical method. The prepared powder has been sintered at 1073 K for 5 hours. The X‐ray diffraction analysis and IR spectroscopy ensure the formation of the required ferrites. The crystallite sizes have been calculated from the X‐ray charts and the average particle sizes have been determined by a particle size analyzer. The average particle size is found to be greater than the corresponding crystallite size for most of the samples because the X‐rays can mainly detect the crystalline (well‐ordered) part of the particle. The AC conductivity, dielectric constant and relative magnetic permeability have been measured as a function of composition. The magnetic permeability obviously decrease with increasing Mg content, whereas the behavior of the electrical properties with the variation of Mg content is not as simple as the behavior of permeability most probably due to the correlation between dielectric behavior and electrical conductivity along with the role of cationic distribution in the A‐ and B‐sites. The prepared samples have been also investigated using the positron annihilation lifetime spectroscopy. The variation of its parameters as a function of composition has been studied and compared with the results of other measurements.

The electrical characteristics have been applied to metal organic vapor Phase deposition, MOVPD‐epitaxial grow n‐Si based Schottky structure. The temperature‐dependent of the electrical characteristics of the Au/n‐Si Schottky diode in the temperature range of 30–400 K were considered. The barrier height and ideality factor of Schottky diodes were obtained. It was observed that the zero bias barrier height decreases and the ideality factor n increases with decreasing temperature. Such behavior is attributed to barrier inhomogeneities by assuming a Gaussian distribution of barrier heights at the interface. Further, the homogeneous barrier height is estimated from the linear relationship between temperature‐dependent experimental effective barrier heights and ideality factors. The effective Richardson constant is determined to be in good agreement with the theoretical value. The temperature‐dependent J‐V characteristics of the Au/n‐Si Schottky diode can be successfully explained on the basis of thermionic em...

We present a resolution of the Klein paradox within the framework of one‐particle relativistic quantum mechanics (no pair production). Not only reflection becomes total but the vacuum remains neutral as well. This is accomplished by replacing the pair production process with virtual negative energy “incidence” within the barrier in a process analogous to the introduction of image charges in electrostatic and virtual sources in optics.

Samples of CR‐39 polyallydiglycol polymer after irradiation with Am‐241 alpha particles were exposed to Nd:YAG(UV) laser pulses with different wavelengths (λ = 355nm and λ = 266nm with same repetition rate of 10Hz and pulse duration of 8 nano seconds). In order to investigate the changes occurred in the original morphology of the latent tracks, samples were etched in 6M NaOH at 70° C for different periods. Our results indicate significant changes in track sizes, shapes and chain‐like structures. The enlargement of average track diameters leading to overlapping of tracks as a function of exposure time and energy was observed. The increase in circular annealed central area around the laser pulses and disappearance of tracks from this area as a function of energy was observed. The results can best be explained by considering that absorption of UV photons by organic molecules which give rise to electronic excitation. It is believed that when a polymer is excited with photons of higher energy, the decomposition and ablation is predominantly photochemical, being caused by the excitation and dissociation of bonds. The result is scission of bonds and the production of a large number of small volatile fragments during the absorption of the UV radiation. Surface morphology and microstructure changes observed are wavelength and exposure time dependent.

Amorphous thin films of Sb65Se35−xGex(x =0, 5, 10, 15, and 20%) were grown with electron beam evaporation technique onto ultra clean glass substrates at room temperature. The as‐deposited films were extensively characterized by X‐ray diffraction. The surface morphology as well as the elemental chemical composition of films were investigated by scanning electron microscopy (SEM). The optical measurements of as‐deposited films were recorded in the wavelength range of 250–2500 nm. The effect of Ge on the optical properties was discussed. Absorption coefficient and band gap of films were determined.

We examine effects on measurable observables in e+e− collisions resulting from the existence of additional neutral gauge bosons originating in extensions of the standard model. In particular, we consider family non‐universal neutral gauge bosons occurring in the minimal supersymmetric standard model and in the Sp(6)L ⊗ U(1)Y model, as well as other theoretically motivated popular neutral gauge bosons. We show how the proper employment of the generation‐dependent couplings of the extra gauge boson, and the appropriate adjustment of the beam polarization, not only improved the identification of the models but also enhanced the discovery potential of the family non‐universal extra gauge bosons.

Thin film of La0.7Sr0.3MnO3 (LSMO) was grown on SrTiO3 pervoskite single crystal substrate at different pressures of oxygen using pulsed laser deposition technique. The x‐ray diffractometry analysis revealed that the LSMO nanoparticles sintered at 1000 °C shows most stable structure. The crystallite size calculated using scherrer formula is comparable with the particle size observed in SEM images. It has been found that the sample grown at highest pressure of oxygen 100 mTorr shows better magnetization.

Highly oriented nanocrystalline, V2O5,nH2O, film was used as a gas sensor. The thin film was deposited on a glass substrate via the sol gel technique. The size of the nanocrystals was found to be 7 nm applying x‐ray diffraction. The electrical resistance of the film was measured successively twice at a fixed temperature of 338 K during alternating heating/cooling process. It is found that the hydrogen maximum response sensing properties reaches 790 times for 100% hydrogen relative to normal air ambient atmospheric conditions. The very high hydrogen sensitivity at such a low operating temperature indicates that the applied procedure is most effective in sensing different hydrogen/air concentration. The obtained results suggest also that the sensor material do release the adsorbed hydrogen during heating up to 453 K, while the material readsorbs the gas while it is being cooled to room temperature. Additionally it may be suggested that this material can act as hydrogen storage as well during the cooling pro...

5th Conference of the Saudi-Physical-Society (SPS), Abha, SAUDI ARABIA, OCT 25-27, 2010; International audience; Small Angle X-ray Scattering (SAXS) has been used to measure in-situ the size, morphology and concentration of soot particles in an ethylene diffusion flame. The results obtained are compared to those taken using other experimental techniques.

Electrostatic storage rings have proven to be invaluable tools for atomic and molecular physics at the ultra‐low energy range from 1 to 100 keV/A. Due to the mass independence of the electrostatic rigidity these machines are able to store a wide range of different particles, from light ions to heavy singly charged bio‐molecules. Their beam dynamics is, however, fundamentally different to magnetic storage rings and therefore needs to be investigated in detail to optimize storage ring performance and experimental output. This paper first gives an overview of existing electrostatic storage rings and their experimental programs. Second, future machines in Heidelberg, Stockholm and the Facility for Antiproton and Ion Research (FAIR) are described and the main challenges are summarized. Finally, the focus is set on a flexible storage ring facility presently being built up at the King Abdulaziz Center for Science and Technology (KACST) in Riyadh, Saudi Arabia, that addresses a broad user community and will allow for a next‐generation experimental program in the low energy regime.Electrostatic storage rings have proven to be invaluable tools for atomic and molecular physics at the ultra‐low energy range from 1 to 100 keV/A. Due to the mass independence of the electrostatic rigidity these machines are able to store a wide range of different particles, from light ions to heavy singly charged bio‐molecules. Their beam dynamics is, however, fundamentally different to magnetic storage rings and therefore needs to be investigated in detail to optimize storage ring performance and experimental output. This paper first gives an overview of existing electrostatic storage rings and their experimental programs. Second, future machines in Heidelberg, Stockholm and the Facility for Antiproton and Ion Research (FAIR) are described and the main challenges are summarized. Finally, the focus is set on a flexible storage ring facility presently being built up at the King Abdulaziz Center for Science and Technology (KACST) in Riyadh, Saudi Arabia, that addresses a broad user community and will allow...

Coherent π0‐photoproduction on the deuteron including polarization effects in the energy region from π‐threshold up to 1 GeV is studied using an enhanced elementary pion photo‐production operator on the free nucleon and a realistic NN potential model for the deuteron wave function. Results for double polarization observables are predicted for which the sensitivity to various models for the elementary pion photoproduction amplitude is investigated. We find considerable dependence of the results on the elementary amplitude. In addition, results for differential cross section are predicted and compared with the experimental data from TAPS and a satisfactory agreement was found.

Ground level concentrations due to emissions from the Jeddah dual—purpose plant (sea water desalination and electric power production) have been estimated using the standard Gaussian plume model (GPM). The main types of pollutants emitted from the plant are: Hydro–carbons HC, carbon monoxide CO, Nitrogen oxides NOx and sulfur dioxide SO2. Thermal stability classes for Jeddah city are estimated for the months of the year (2007). It was found that the dominant stability class for the city is the moderately unstable class B (according to pasquill classification). The results of stability classes’ evaluation together with the meteorological wind—data are used to predict the ground level concentration (glc) of the pollutants against the downwind distance from the plant location. The month and day of each calculated value of the pollutant concentration during the year (2007) have been specified. The maximum (glc) and their positions on the ground for each pollutant are found.

Measurement of indoor Concentrations were performed in Zulfi city of Saudi Arabia, using CR-39 track etch detectors. This investigation focused on the influence of different parameters, namely different locations, school categories, school building types, and room type as well as on the existence of differences in radon concentration at floor levels. We divided the Zulfi city into five regions, keeping in mind their geographical locations between Tuwaiq Mountains and Al-Thuwayrat sands. The measured average radon concentrations for regions 1-5 respectively are: 87.0{+-}14.2 Bq/m{sup 3}, 83.4{+-}6.0 Bq/m{sup 3}, 61.6{+-}6.4 Bq/m{sup 3}, 63.7{+-}5.4 Bq/m{sup 3} and 87.5{+-}6.Bq/m{sup 3} and the minimum concentrations are 28.0 Bq/m{sup 3}, 5.5 Bq/m{sup 3}, 1.1 Bq/m{sup 3}, 1.0 Bq/m{sup 3} and 24 Bq/m{sup 3} respectively. These results are still within normal limits and below the action level of 148 Bqm{sup -3} set by the U.S. Environmental Protection Agency (EPA). A test of significance using Minitab program was applied to investigate if radon levels in regions are significantly different from each other. We tried all combinations, and found the following results. The ''within regions''(different location) test yielded, region 2 is not significant versus region ''1''(p = 0.783) and versus region ''5''(P = 0.646), whereas it is significant versusmore » region ''3''(P = 0.0160) and also versus region ''4''(p = 0.018). We investigated government and rented school's building also and none was found significantly different (p = 0.052). Floors of the same building were tested in order to examine the radon concentration as a function of storey level. No significant difference was observed at floor levels (p = 0.009). When girl's schools versus Boys and kindergartens schools were tested they were found significantly different. It is believed that this significant difference is due to geographical nature of the area, since most of the girl's schools were selected from regions 2 and 3, these regions are relatively close to the Tuwaiq mountains whereas other regions are near to the Al-Thuwayrat sands.« less

We derive an elegant analytic formula for the energy spectrum of the relativistic Dirac‐Morse problem. In the nonrelativistic limit, it reproduces the well‐known result. This finding is significant when using the Morse potential as a model to describe the vibrational spectrum of diatomic and polyatomic molecules at strong coupling.

We obtain an exact solution of the 1D Dirac equation for a square well potential of depth greater then twice the particle's mass. The energy spectrum formula in the Klein zone is surprisingly very simple and independent of the depth of the well. This implies that the same solution is also valid for the potential box (infinitely deep well). In the nonrelativistic limit, the well-known energy spectrum of a particle in a box is obtained. We also provide in tabular form the elements of the complete solution space of the problem for all energies.

A new design of an optimized optical system for the reduction of a laser beam size at a certain wavelength is presented. The technique of this design is based upon replacing the elements of a four‐lenses optical system, which is designed for this purpose, by one element made of an axial gradient index material. The optical performance of this new design, which has a power as that of its counterpart, is tested by the evaluation of many merit functions. The graphical comparisons between the corresponding values of both systems merit functions show that the new design has a less amount of geometrical aberrations relative to that of its counterpart.

A technique for entangling closely separated atoms by the process of dissipative spontaneous emission is presented. The system considered is composed of two non‐identical two‐level atoms separated at the quarter wavelength of a driven standing wave laser field. At this atomic distance, only one of the atoms can be addressed by the laser field. In addition, we arrange the atomic dipole moments to be oriented relative to the inter‐atomic axis such that the dipole‐dipole interaction between the atoms is zero at this specific distance. It is shown that an entanglement can be created between the atoms on demand by tuning the Rabi frequency of the driving field to the difference between the atomic transition frequencies. The amount of the entanglement created depends on the ratio between the damping rates of the atoms, but is independent of the frequency difference between the atoms. We also find that the transient buildup of an entanglement between the atoms may differ dramatically for different initial atomic conditions.

The present study devoted to studying the effect of particle size on electrical properties of multiferroic materials; YbMnO3 and Yb0.9Sr0.1MnO3 because of the growing interest in multiferroic materials. This great attention increased due to the potential applications in spintronics and in ferroelectromagnets, in addition to the inherent interest in the underlying physics of the coexistence of ferroelectricity and ferromagnetism. Ytterbium manganites were prepared using co‐precipitation method from the initial pure chlorides of ytterbium, strontium and manganese to react with pure sodium hydroxide with the proper molar ratio. The synthesized semiconductor composites were studied in details in terms of their morphological and structural properties. The energy dispersive spectroscopy EDS reveals that the synthesized composites are in a proper stoichiometry of the proposed structure. The X‐ray analysis of Yb0.9Sr0.1MnO3 exhibited that crystal structure is possessing mixed orthorhombic/hexagonal phase with spa...

The orthoferrimanganites Nd0.65Sr0.35FexMn1−xO3 (x = 0.1, 0.3, 0.6) have been investigated using XRD, MOssbauer spectroscopy, magnetization and conductivity techniques. The XRD reflections exhibit single phase structure. The paramagnetic–superparamagnetic‐magnetic transitions were observed from MOssbauer spectra and magnetization measurements in the temperature range from the liquid nitrogen to the room temperature. The conductivity study of the x = 0.1 and 0.3 show semiconducting behavior with more pronounced conductivity for the latter leading to an activation energy double that of the former. The effect of the Fe substitution on the electronic and magnetic properties was analyzed and discussed.

This study involves the measurement of radon concentrations in agricultural soil from two date Palm farms in Al-Qateef province using CR-39 detector. In each farm the palm trees are arranged in rows separated by the irrigation reservoirs. The first farm is about 10000 m{sup 2} and has 350 palm trees and the second farm is about 7000 m{sup 2} and has 320 palm trees. The average distance between trees is about 5.5 m. The rows are separated by an irrigation reservoir where fertilizers are added. Sixty soil samples were collected from each farm and classified in paperboard boxes. These samples were taken from different depths and positions between the trees and from the irrigation reservoir.A newly designed tag type dosimeter is used in which the alpha tracks are registered on both sides of the CR-39 detector. The tag dosimeter was calibrated against a cup type dosimeter which was calibrated at the National Radiological Protection Board (NRPB) at the U.K.The detectors were left to count for five months and then chemically treated in the standard way. Finally an optical microscope is used to count alpha tracks and the data are treated statistically.The study is set to test for significant differences inmore » radon concentrations at different positions and depths in the barren and fertilized soils in the two farms. Measured radon concentrations ranged between 42 and 344Bq/m{sup 3}. No significant difference between the mean concentration values in soil samples taken between the trees and that taken at the depth of 50 cm from the irrigation reservoir. Significant difference was however found between radon concentrations in samples collected directly from the surface of the irrigation reservoir where fertilizers are introduced and those taken from the other two positions. The used fertilizers are found to have higher contents of uranium which is limited to the surface soil of the irrigation reservoir.« less

A Na2B4O7 glass sample was prepared by melt quenching technique. The complex dielectric permittivity e*(f,T) has been measured in the frequency range from 10 mHz to 1 MHz in the temperature range from room temperature to 300 °C. From the dielectric spectra, it is evident that there are at least one dipolar relaxation process occurring between 103 Hz–106 Hz. The low frequency realm of the spectrum is dominated by dc conductivity which could be successfully modeled by the 1/ω law. The temperature dependence of the dc conductivity σdc(T) = σ0e−EA/kT is Arrhenius‐like with activation energy equals to 0.64 eV. The ac conductivity has been calculated and found to vary with frequency as fSac, the exponent Sac decreases slightly with increasing temperature.

Entanglement is one of the key features of the quantum mechanical systems that is fundamentally differen from a classical system, in consequence the dynamical behavior of entangled states is of a great significance. In this paper we investigate the phenomenon of sudden death of entanglement in a bipartite system subjected to squeezed vacuum reservoirs with an arbitrary initial pure entangled state between two fields in the cavities. To estimate the degree of entanglement we use the logarithmic negativity. We show that the sudden death time of the entangled states depends on the initial preparation of the entangled state, the phase shift between them and the parameters of the squeezed vacuum reservoir. We derive the conditions, which assure that The states remain entangled although the interaction with the reservoir. The sudden death time of the entangled states is related to the squeezed parameter of the reservoir and the phase shift between the initial entangled states.

Well‐crystallized branched Indium (In)‐doped ZnO nanowires were grown on silicon substrate via simple thermal evaporation process by using metallic zinc and indium powders in the presence of oxygen. The as‐grown branched nanowires were examined in terms of their morphological, structural and optical properties using field emission scanning electron microscopy (FESEM) attached with energy dispersive spectroscopy (EDS), X‐ray diffraction and room‐temperature photoluminescence (PL) spectroscopy. The morphological and structural characterizations confirmed that the as‐grown products are branched nanowires, grown in high‐density and possessing well‐crystalline structures. The room‐temperature photoluminescence (PL) spectrum exhibited a very small UV emission and a broad band in the visible region indicating the presence of structural defects due to insertion of In‐atoms in the lattices of as‐grown nanowires. The presence of a strong green emission in the room‐temperature PL spectrum demonstrates that these str...

We deal here with the application of the Nuclear Born Oppenheimer (NBO) method to the description of nuclear rotations. As an edifying illustration, we apply the NBO formalism to study the rotational motion of nuclei which are axially‐symmetric and even, but whose shells are not closed. We focus, in particular, on the derivation of expressions for the rotational energy and for the moment of inertia. Additionally, we examine the connection between the NBO method and the self‐consistent cranking (SCC) model. Finally, we compare the moment of inertia generated by the NBO method with the Thouless‐Valantin formula and hence establish a connection between the NBO method and the large body of experimental data.

In this paper, CuO layered hexagonal disks based ammonium hydroxide chemical sensor has been fabricated which demonstrated good sensitivity and detection limit. The CuO layered hexagonal disks were synthesized in large quantity via facile hydrothermal process at low‐temperature of 130 °C and characterized in detail in terms of their structural and optical properties [1]. The detailed structural and optical properties of as‐synthesized CuO layered hexagonal disks confirmed the good crystallinity with monoclinic structure and good optical properties for synthesized products [1]. The fabricated ammonium hydroxide chemical sensor based on CuO layered hexagonal disks demonstrate a good sensitivity of 0.07166 μA cm−2 mM−1, detection limit = 1.333 μM, response time less than 10 s, linear dynamic range (LDR) from 5.0 μM to 5.0 mM. This study reveals that simply synthesized CuO materials can be efficiently as an electron mediator to fabricate efficient chemical sensors.

A versatile ion‐beam injector is presently being constructed at the National Centre for Mathematics and Physics (NCMP) at the King Abdul‐Aziz City for Science and Technology (KACST), Saudi Arabia. This versatile injector will provide an electrostatic storage ring with high‐quality ion beams of energies up to 30 keV per charge q. It will also allow for crossed‐beams experiments in single‐pass setups. The injector has been designed to include beams from two different ion sources, switched by a 90° deflection setup, and to allow for matching of the beam parameters to the Twiss parameters of the ring. The injector is equipped with two crossed beam‐lines (inlets), with duplicated beam extraction and acceleration systems. As part of the initial setup, a simple electric discharge ion source has been developed for commissioning of the whole injector. In this paper, we report on the ion optics layout and the design parameters of the injector.

A brief review is presented for the pre‐history and discovery of fullerenes. Single‐site potentials with parameters proposed by Girifalco was used to describe the interactions of the fullerene molecules C70 and C96. We present theoretical model for calculating the thermodynamic properties of liquid for both C70 and C96 by means of an improved equation of state (EOS), in which the particles are interacting via pair wise interaction composed of suitable linear combination of three Yukawa functions (3YK). The proposed equation of state provides a powerful mathematical formalism for the Helmholtz free energy and the pressure within the series mean‐spherical approximation (SMSA) which are the basic ingredients to compute the liquid‐vapour coexistence curve of C70 and C96 as well as the other thermodynamic properties for the bulk liquid and the vapour phases. The comparisons with Gibbs ensemble Monte Carlo (GEMC) simulations and the self‐consistent Ornstein‐Zernike approximation (SCOZA) were carried out. The es...

CdS thin films were deposited by a chemical bath deposition technique (CBD). The bath solution is composed of CdCl2 (0.1 M) salt as a source for Cd and thiourea (0.1M) as a source of sulphur (S). To avoid the toxicity and volatility of the commonly used ammonia, ethanolamine (ETA ) is used as complexing agent. Films were deposited with different times from 30 to 120 minutes in order to study the films growth mechanism. The solution temperature was fixed at 60°C. The structural and morphological films characterizations were carried by XRD analysis and AFM observations. From the XRD analysis we inferred that obtained CdS films have a pure hexagonal structure with the preferential orientation along the plane (101). The pure hexagonal structure is highly recommended for the realization of CdTe/ CdS or CuInSe/CdS solar cells. The presence of the hexagonal structure and the low growth rate in order of 1nm/min suggest that the growth mechanism is achieved through the ion by ion process. The optical characterizat...

Recent work in the author’s laboratory has led to the development of surface modification techniques for the fabrication of nanostructures that are inexpensive, highly scalable and do not require use of lithography. One such process creates nanofiber arrays of single crystal TiO2 by hydrogen containing gas phase reaction. On the other hand, on Au‐catalyzed (001) surface of TiO2, oriented nano‐fibers can be grown with 〈001〉 and 〈110〉 alignments using H2/N2 heat treatment. H2/N2 heat treatment was also used to grow nanofibers on polycrystalline SnO2 in regions of the sample coated with gold, showing directional growth on grains with crystal facets. We developed yet another process to create nanofibers of TiO2 on Ti metal and Ti alloys via oxidation under a limited supply of oxygen. Finally, this article describes another unique nano‐structure created during thermal annealing of an oxide on top of another oxide substrate that self‐assembles along a preferred direction of the substrate.

A novel Electrostatic Storage Ring (ESR) for beams at energies up to 30keV/q is now being constructed at the National Centre for Mathematics and Physics (NCMP), King Abdul‐Aziz City for Science and Technology (KACST). The ring is designed to be the core of a highly flexible experimental platform that will combine a large package of complementary beam techniques for atomic and molecular physics and related fields. The lattice design had to cover the different experimental techniques that the ring will be equipped with, such as e.g. Electron‐Ion, Laser‐Ion, Ion‐Ion or Ion‐Neutral beams, in both crossed and merged‐beam configurations. The development of such an ESR is realized in a staged approach, in which a simple and early‐run adaptation of the ring is built first, and then this basic version is upgraded to a higher symmetry of the ultimate version of the ring. Here, we report a general overview of this technical development with a focus on the layout of the first built stage of the ring.