UK PubMed Central (United Kingdom)

Different tombusviruses were able to support the replication of either homologous or heterologous defective interfering (DI) RNAs, and those infected plants usually developed typical attenuated symptoms....Full Text Available

Science.gov (United States)

Splenectomy or pretreatment of adult hamsters with cyclophosphamide (Cytoxan) increased the lethality of the TC-83 vaccine strain of Venezuelan encephalitis virus (VEE), inoculated subcutaneously, from 12% for normal hamsters to 75 and 76% respectively. A...

UK PubMed Central (United Kingdom)

In laboratory studies, hamsters (Mesocricetus spp.) exhibit intense male-male aggression, thus making them an excellent model system for studies of the functional and mechanistic...Full Text Available

Science.gov (United States)

The study was conducted to determine potential target organ toxicity and its reversibility in hamsters following twice daily oral doses of NSC-D629243 for 28 consecutive days. Male and female hamsters were administered NSC-D629243 dissolved in sesame oil ...

Science.gov (United States)

Increasing the Mg(2+) concentration results in a depression of succincoxidase-linked state 3

UK PubMed Central (United Kingdom)

Hamsters breathed, nose-only, for 13 weeks, 5 days/week, 6 hr/day, either man-made vitreous fiber (MMVF)10a, MMVF33, or long amosite asbestos at approximately 300 World Health Organization (WHO) fibers/cc...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundProcessing of multimodal information is a critical capacity of the human brain, with classic studies showing bimodal stimulation either facilitating or interfering in perceptual...Full Text Available

UK PubMed Central (United Kingdom)

Epidermal growth factor receptor (EGFR)-specific monoclonal antibodies predominantly inhibit colorectal cancer (CRC) growth by interfering with receptor signaling. Recent analyses have shown that patients...Full Text Available

UK PubMed Central (United Kingdom)

MicroRNAs (miRNAs) are endogenously encoded small noncoding RNAs, derived by processing of short RNA hairpins, that can inhibit the translation of mRNAs bearing partially complementary target sequences....Full Text Available

Science.gov (United States)

Adolescent exposure to anabolic androgenic steroids (AAS) alters the development and activity of the glutamate neural system in the latero-anterior hypothalamus (LAH) in hamsters (Mesocricetus auratus); that is, an important neural component of the adolescent AAS-induced aggressive response. In this article, we used retrograde tracing to investigate glutamate-specific alterations in the connections between the LAH and several other nuclei implicated in adolescent AAS-induced aggression. Briefly, hamsters were treated with AAS or sesame-oil control during adolescence and then microinjected with retrograde tracer into the medial amygdala (MeA), lateral septum (LS), or bed nucleus of the stria terminalis (BNST). Brains were then processed for vesicular glutamate transporter 2 (VGLUT2) and examined for AAS-induced changes in the number VGLUT2 cells containing retrograde tracer (VGLUT2/tracer) within the LAH. It is interesting to note that while ...

Energy Technology Data Exchange (ETDEWEB)

The distribution of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of /sup 3/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid.

UK PubMed Central (United Kingdom)

The study of blocking factors requires in vitro assay of cell mediated immunity that parallels the in vivo response. By microcytotoxicity testing, progressor and immune peripheral blood lymphocytes...Full Text Available

UK PubMed Central (United Kingdom)

The mutagenic and cytotoxic activity of two newly synthesized doxorubicin derivatives and of one daunorubicin derivative were studied in V79 Chinese hamster cells and bacteria (Salmonella typhimurium...Full Text Available

International Nuclear Information System (INIS)

In recent years it has become evident from epidemiological and experimental data that a large number of environmental factors, including diet, play a role in modifying the incidence of cancer. Cell culture systems in which oncogenic transformation serves as an end point are powerful tools for evaluating these questions. Using such systems it has been shown recently that pyrolysis products from charred surfaces of broiled meat and fish can transform hamster embryo cells in vitro as well as produce tumors in the animal. Our studies in vitro have demonstrated the oncogenic potential of ionizing radiation in both hamster and human cells and have established in hamster cells the dose response relationship at doses ranging from 1 to 600 rad for x-rays and 0.1 to 150 rad for neutrons. The present work was aimed at evaluating whether there exists a cocarcinogenic interaction between a pyrolysis product and x-rays in their ability ...

International Nuclear Information System (INIS)

Calculations, drawing principally on developments at AERE Harwell, of the relaxation about lattice defects are reviewed with emphasis on the techniques required for such calculations. The principles of defect modelling are outlined and various programs developed for defect simulations are discussed. Particular calculations for metals, ionic crystals and oxides, are considered. (UK).

Energy Technology Data Exchange (ETDEWEB)

A strong effort is currently being devoted to the investigation of defects and diffusion phenomena in silicon. This effort is not only driven by the stringent technological requirements for the processing of integrated circuits of increased complexity and miniaturization, but also by the lack of fundamental understanding of many of the critical parameters and mechanisms involved. Experimental and theoretical investigations are needed to identify the properties of the defects, the mechanisms of impurity diffusion and the strength of impurity-defect, defect-defect, and impurity-impurity interactions. This volume provides a unique and interdisciplinary forum for the discussion of experimental, theoretical and applied aspects of defects and diffusion phenomena in silicon. Topics include: defect properties and diffusion phenomena in silicon; experimental and ...

UK PubMed Central (United Kingdom)

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dioxin-like compounds are widely encountered toxic substances suspected of interfering with the endocrine systems of humans and wildlife,...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

The chemopreventive efficacy of turmeric has been established in experimental systems. However, its mechanism(s) of action are not fully elucidated in vivo. The present study investigates the mechanism of turmeric-mediated chemoprevention in 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis at 2, 4, 6, 10 and 12?weeks. Dietary turmeric (1%) led to decrease in DMBA-induced tumor burden and multiplicity, and enhanced the latency period in parallel, to its modulatory effects on oncogene products and various cellular responses during HBP tumorigenesis. DMBA-induced expression of ras oncogene product, p21 and downstream target, the mitogen-activated protein kinases were significantly decreased by turmeric during HBP carcinogenesis. Turmeric also diminished ...

British Library Electronic Table of Contents (United Kingdom)

Abstract This study reports the effects of varying concentrations of copper sulfate on the metabolic and gene transcriptional profile of a recombinant Chinese hamster ovary (CHO) cell line producing an immunoglobulin G (IgG)-fusion protein (B0). Addition of 50 M copper sulfate significantly decreased lactate accumulation in the cultures while increasing viable cell density and protein titer. These changes could be seen from day 6 and became increasingly evident with culture duration. Reducing the copper sulfate concentration to 5 M retained all the above beneficial effects, but with the added benefit of reduced levels of the aggregated form of the B0 protein. To profile the cellular changes due to copper sulfate addition at the transcriptional level, Affymetrix CHO microarrays were used to...

International Nuclear Information System (INIS)

Kinetic Monte Carlo simulations are used to analyze the ripening and dissolution of small Si interstitial clusters and #left brace#113#right brace# defects, and its influence on transient enhanced diffusion of dopants in silicon. The evolution of Si interstitial defects is studied in terms of the probabilities of emitted Si interstitials being recaptured by other defects or in turn being annihilated at the surface. These two probabilities are related to the average distance among defects and their distance to the surface, respectively. During the initial stages of the defect ripening, when the defect concentration is high enough and the distance among them is small, Si interstitials are mostly exchanged among defects with a minimal loss of them to the surface. Only when defects grow to large sizes and their concentration ...

Science.gov (United States)

Abstract Unrefined and refined black raspberry seed oils (RSOs) were examined for their lipid-modulating effects in male Syrian hamsters fed high-cholesterol (0.12% g/g), high-fat (9% g/g) diets. Hamsters fed the refined and the unrefined RSO diets had equivalently lower plasma total cholesterol and high-density lipoprotein (HDL) cholesterol in comparison with the atherogenic coconut oil diet. The unrefined RSO treatment group did not differ in liver total and esterified cholesterol from the coconut oil-fed control animals, but the refined RSO resulted in significantly elevated liver total and esterified cholesterol concentrations. The unrefined RSO diets significantly lowered plasma triglycerides (46%; P=.0126) in comparison with the coconut oil diet, whereas the refined RSO only tended to lower plasma triglyceride (29%; P=.1630). Liver triglyceride concentrations were lower in the unrefined (46%; P=.0002) and refined (36%; P=.0005) RSO-fed ...

International Nuclear Information System (INIS)

PuO_2 particles behaved similarly in the lungs of rat and hamster. The relative concentrations of PuO_2 up to 1-yr postexposure were 1.0 for lung parenchyma, 1.3 for subpleural areas, 0.5 for peribronchiolar regions and 0.2 for perivascular regions in the lungs.

Science.gov (United States)

The state of chromatin during the cell cycle was examined using synchronized cultures of CHO hamster cells. Results support Mazia's dynamic chromosome cycle model and indicate that DNA-interactive chemotherapeutic agents elicit different types of kinetic responses in treated cells, suggesting a degree of specificity of interaction between various alkylating and intercalating agents and the genome. Effects of sarkosyl crystals, heparin, and chemotherapeutic agents, neocarzinostatin and adriamycin, on chromation are discussed. (HLW)

UK PubMed Central (United Kingdom)

Congenital deformities involving the coverings of the nervous system are called neural tube defects (NTDs). NTD can be classified as neurulation defects, which occur by stage 12, and postneurulation...Full Text Available

UK PubMed Central (United Kingdom)

Familial defective apolipoprotein (apo) B-100 is a genetic disease that leads to hypercholesterolemia and to an increased serum concentration of low density lipoproteins that bind defectively to the...Full Text Available

CERN Document Server

The existence of light hidden sectors is an exciting possibility that may be tested in the near future. If DM is allowed to decay into such a hidden sector through GUT suppressed operators, it can accommodate the recent cosmic ray observations without over-producing antiprotons or interfering with the attractive features of the thermal WIMP. Models of this kind are simple to construct, generic and evade all astrophysical bounds. We provide tools for constructing such models and present several distinct examples. The light hidden spectrum and DM couplings can be probed in the near future, by measuring astrophysical photon and neutrino fluxes. These indirect signatures are complimentary to the direct production signals, such as lepton jets, predicted by these models.

International Nuclear Information System (INIS)

Results of the evaluation of the scattered radiation effect on the image of defects in examined products are given. The formula is suggested which characterizes the image of defects on a scintillation screen as well as accumulation factors are calculated by the Monte-Carlo method. Values of fluctuations of absorbed energy in the screen used for the evaluation of sensitivity are experimentally obtained. The effect of high-energy bremsstrahlung on the defect detection is analyzed.

Czech Academy of Sciences Repository

Full Text Available

International Nuclear Information System (INIS)

... defects doped materials germanium infrared radiation monocrystals neutron

KoreaScience (Korea)

Full Text Available

British Library Electronic Table of Contents (United Kingdom)

This paper deals with surface defects of automobile outer panels, which alter significantly the vehicle quality. Such defects occur during springback, after forming or flanging steps, and are characterized by concave depression of small amplitude over the convex shape of the part. The aim of this work is to reproduce at the laboratory scale a surface defect that occurs after flanging on a geometry similar to a door upper corner. A dedicated device has been designed in order to generate small size surface defects during flanging of metallic thin sheets. The outer surface of the sample was digitalized and the spatial geometry of the defect was evaluated from curvature change along 2D profiles. This study shows that the flanging height does not influence significantly the surface defect geome...

Energy Technology Data Exchange (ETDEWEB)

Marmesin was isolated from the medicinal plant, Afraegle paniculata. Its cytotoxicity and mutagenicity in Chinese hamster V79 cells when sensitized to near ultraviolet (NUV) and long wavelength ultraviolet light or black light (BL) were assayed. Marmesin was extremely cytotoxic in the dark. This cytotoxicity was photoenhanced in NUV and BL; the photoenhanced lethality being higher in NUV than in BL. The LD/sub 50/ of marmesin under NUV and BL photosensitization were 0.002 ..mu..M and (0.012 ..mu..M), respectively. In the absence of NUV and BL, marmesin's LD/sub 50/ was 0.013 ..mu..M.NUV and BL without marmesin were not significantly cytotoxic at the fluence rates of 0.29 W/m/sup 2/ and 4.2 W/m/sup 2/, respectively, for up to 20 min. In contrast to the observed high cytotoxicity of marmesin, its mutagenicity at the HGPRT locus (Asub(z)Gsup(r)) was weak. The implication of this result in the high incidence of skin cancer in Nigeria in which A. paniculata is ...

Energy Technology Data Exchange (ETDEWEB)

A comparison of the concentration-response effects of inhaled ozone (O/sub 3/) and phosgene (COCl/sub 2/) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation toxicity studies. The effect of 4-h exposures to ozone at concentrations of 0.2, 0.5, 1.0, and 2.0 ppm, and to COCl/sub 2/ and 0.1, 0.2, 0.5, and 1.0 ppm was determined in rabbits, guinea pigs, rats, hamsters, and mice. Lavage fluid protein (LFP) accumulation 18-20 h after exposure was used as the indicator of O3- and COCl/sub 2/-induced pulmonary edema. All species had similar basal levels of LFP (250-350 mg/ml) when a volume of saline that approximated the total lung capacity was used to lavage the collapsed lungs. Ozone effects were most marked in guinea pigs, which showed significant effects at 0.2 ppm and above. Mice, hamsters, and rats showed effects at 1.0 ppm O3 and above, while rabbits responded ...

International Nuclear Information System (INIS)

Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak ...

International Nuclear Information System (INIS)

A deep band of #left brace#311#right brace# defects was created 520 nm below the silicon surface with a 350 keV Si implant followed by a cluster-forming rapid thermal anneal (800 C, 1000 s). Chemical etching was used to vary the depth to the surface of the #left brace#311#right brace#-defect band. Afterwards, the defect dissolution was investigated at 750 C for different times. Varying the depth in this fashion assures that only the depth and no other feature of the cluster distribution is changed. The #left brace#311#right brace# defects were analyzed by plan-view, transmission electron microscopy. We show that the dissolution time of the #left brace#311#right brace#-defect band varies linearly with depth, confirming that surface recombination controls the dissolution and is consistent with analogous observations of transient enhanced diffusion.

International Nuclear Information System (INIS)

Amorphization and a dual implant technique have been used to manipulate residual defects that persist following implantation and post-implant thermal treatments. Residual defects can often be attributed to ion-induced defect excesses. A defect is considered to be excess when it occurs in a localized region at a concentration greater than its complement. Sources of excess defects include spatially separated Frenkel pairs, excess interstitials resulting from the implanted atoms, and sputtering. Preamorphizing prior to dopant implantation has been proposed to eliminate dopant broadening due to ion channeling as well as dopant diffusion during subsequent annealing. However, transient-enhanced diffusion (TED) of implanted boron has been observed in pre-amorphized Si. The defects driving this enhanced boron diffusion are thought to be the extended interstitial-type ...

UK PubMed Central (United Kingdom)

Strategies to combine aspirated marrow cells with scaffolds to treat connective tissue defects are gaining increasing clinical attention and use. In situations such as large defects where initial...Full Text Available

International Nuclear Information System (INIS)

The federating theme of superconductivity has given rise to a number of experimental studies of point defects in solids as different as transition metals (V, Nb, ...), A-15 compounds (V_3Si, Nb_3Ge, ...), or perovskite-like copper oxides. Some of these experiments are presented here. (orig.).

International Nuclear Information System (INIS)

We present an atomistic simulation of the Ostwald ripening of extrinsic defects (clusters, #left brace#1 1 3#right brace#s and dislocation loops) which occurs during annealing of ion implanted silicon. The model describes the capture and emission of Si interstitial atoms to and from extrinsic defects of sizes up to thousands of atoms and includes a loss term due to the flux of interstitials to the recombining surface. Key input parameters of the simulation are the variations of the formation energy and of the capture efficiency with the size of the different defects. This model shows that the kinetics of the well-known dissolution of #left brace#1 1 3#right brace# defects is only driven by the recombination efficiency at the surface and the distance from the defects to the sample surface. We have subsequently used this model to study defect evolution in low and ...

UK PubMed Central (United Kingdom)

ObjectivesIn 2003, the Omani Ministry of Health Child Health Care Program initiated a national Birth Defects (BD) Register. This paper reviews the magnitude and risk factors of birth...Full Text Available

UK PubMed Central (United Kingdom)

Over the past two decades, combined advances in genetics, developmental biology and biochemistry have transformed the study of human birth defects. This review describes the importance of genome architecture,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A quantitative transmission electron microscopy (TEM) study on the depth profile of extended defects, formed after Si implantation, has been carried out. Two different Si{sup +} implant conditions have been considered. TEM analysis for the highest energy/dose shows that {l_brace}1 1 3{r_brace} defects evolve into dislocation loops whilst the defect depth distribution remains unchanged as a function of annealing time. For the lowest energy/dose, {l_brace}1 1 3{r_brace} defects grow and dissolve while the defect band shrinks preferentially on the surface side. At the same time, extraction of boron transient enhanced diffusion (TED) as a function of depth shows a decrease of the supersaturation towards the surface, starting at the location of the defect band. The study clearly shows that in these systems the silicon surface is the principal sink for interstitials. ...

UK PubMed Central (United Kingdom)

Generation of replicative defective viruses is frequently observed during viral infections. We now report that encapsidation and reverse transcription of spliced viral RNA is an additional mechanism...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The nitrogen content of 10 medicinal plant species has been determined by fast-neutron activation analysis (FNAA). Correction factors for the effects of the /sup 16/O(p,..cap alpha..)/sup 13/N knock-on proton-induced reaction and the (n,2n) reactions, which produce interfering positron-emitting radionuclides, have also been determined. The total relative interference from the /sup 16/O(p,..cap alpha..)/sup 13/N and (n,2n) reactions of K, Cl, Fe and Br was found to be 5.1 to 32.1% for the plant samples.

CERN Document Server

We investigate opportunistic cooperation between unlicensed secondary users and legacy primary users in a cognitive radio network. Specifically, we consider a model of a cognitive network where a secondary user can cooperatively transmit with the primary user in order to improve the latter's effective transmission rate. In return, the secondary user gets more opportunities for transmitting its own data when the primary user is idle. This kind of interaction between the primary and secondary users is different from the traditional dynamic spectrum access model in which the secondary users try to avoid interfering with the primary users while seeking transmission opportunities on vacant primary channels. In our model, the secondary users need to balance the desire to cooperate more (to create more transmission opportunities) with the need for maintaining sufficient energy levels for their own transmissions. Such a model is applicable in the emerging area of cognitive ...

Energy Technology Data Exchange (ETDEWEB)

Depth resolved positron annihilation studies on Pd/Si thin film system have been carried out to investigate silicide phase formation and vacancy defect production induced by thermal annealing. The evolution of defect sensitive S-parameter clearly indicates the presence of divacancy defects across the interface, due to enhanced Si diffusion beyond 870 K consequent to silicide formation. Corroborative glancing incidence X-ray diffraction (GIXRD), Auger electron spectroscopy (AES) and Rutherford backscattering spectrometry (RBS) have elucidated the aspects related to silicide phase formation and Si surface segregation.

CERN Document Server

We show that in the Landau gauge of the SU(2) Yang-Mills theory the residual global symmetry supports existence of the topological vortices which resemble disclination defects in the nematic liquid crystals and the Alice (half-quantum) vortices in the superfluid heluim 3 in the A-phase. The theory also possesses half-integer and integer charged monopoles which are analogous to the point-like defects in the nematic crystal and in the liquid helium. We argue that the deconfinement phase transition in the Yang-Mills theory in the Landau gauge is associated with the proliferation of these vortices and/or monopoles. The disorder caused by these defects is suggested to be responsible for the confinement of quarks in the low-temperature phase.

International Nuclear Information System (INIS)

The electronic structure of the clusters [V_3Si_4]"1"2"-, [Nb_3Sn_4]"1"2"-[Mo_3Ge_4]"1"5"- in crystalline V_3Si, Nb_3Sn, Mo_3Ge compounds is calculated by the Extended Hueckel method. The influence of different types of radiation induced defects on the density of states at the Fermi level (the anti-site defects, the displacement of atoms in linear chains, the vacancy-interstitial type defects) is considered. (author).

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Measurements of the temperature dependence of the electrical resistivity and correlations observed with T/sub c/ for V_3Si, V_3Ge, and A-15 Nb-Ge show (i) the existence of a universal defect in the A-15 superconductors which is not nonstoichiometry, (ii) a normal state anomaly also strongly influenced by the defects, and (iii) evidence that T/sub c/ and the electron-phonon interactions for transport processes are approx.100 times more sensitive to defect producing sample modifications in the A-15 compounds than in Nb.

British Library Electronic Table of Contents (United Kingdom)

Ventricular septal defect after acute myocardial infarction (AMI) is a complication associated with poor outcome in the absence of intervention. We report a case of successful TEE guided transcatheter closure of a post myocardial infarction (MI) ventricular septal defect (VSD) with an Amplatzer occluder in a 79 years old male with cardiogenic shock.

International Nuclear Information System (INIS)

The defect-induced effect on superconducting transition temperature T_c of A-15 compounds is examined. T_c is found from the Eliashberg equations which take into account the defect-induced changes in the electron-phonon spectral function and electron density of states. The dependence of T_c on the defect type in the superconductor is obtained.

International Nuclear Information System (INIS)

Radionuclide (R) sorption from a solution (vapor) by freshly formed crystals with production of substitution solid solutions under different types of self-disordering is studied. Changes of self-defectiveness and macrodefectiveness with time and effect of radiation defects in the presence of P macroquantities are taken into account. An analysis for monodispersed sorbents is performed. It is shown that the achievement of equilibrium within a reasonable time in impurity-solid phase system depends on defectiveness which ensures a required level of the coefficient of impurity diffusion in sorbent crystals.

Science.gov (United States)

The defect-induced electron lifetime and energy-gap anisotropy effects on the T/sub c/ of the A-15 compounds are examined. A self-consistent model calculation demonstrates that the various defect dependences of T/sub c/ can be qualitatively understood in terms of the electron-lifetime effect.

British Library Electronic Table of Contents (United Kingdom)

Surveillance of a population, such as a weapon stockpile, is needed to discover manufacturing defects as well as deterioration as the population ages. This article considers the risks of sampling rates for surveillance from three perspectives: detection probability of defects in a proportion of a population with pass/fail data, detection of a trend in a defective proportion of the population with pass/fail data, and detection of a trend with quantitative degradation measurements. Understanding of these risks will help the decision maker choose a sampling rate to protect against such problems of a specified size at a tolerable risk.

International Nuclear Information System (INIS)

We provide a brief review of our recent results from optically detected magnetic resonance studies of grown-in non-radiative defects in two most important dilute nitride systems-Ga(In)NAs grown on GaAs substrates and Ga(Al,In)NP grown on Si and GaP substrates. These results have led to the identification of defect complexes in the alloys, involving intrinsic defects such as As_G_a antisites and Ga_i self-interstitials. They have also shed light on formation mechanisms of the defects and on their role in non-radiative carrier recombination that is harmful to the performance of potential optoelectronic and photonic devices based on these dilute nitrides.

DEFF Research Database (Denmark)

We propose a new physical implementation of spin qubits for quantum information processing, namely defect states in antidot lattices defined in the two-dimensional electron gas (2DEG) at a semiconductor heterostructure. Calculations of the band structure of a periodic antidot lattice are presented. A point defect is created by removing a single antidot, and calculations show that localized states form within the defect, with an energy structure which is robust against thermal dephasing. The exchange coupling between two electrons residing in two tunnel-coupled defect states is calculated numerically. We find results reminiscent of double quantum dot structures, indicating that the suggested structure is a feasible physical implementation of spin qubits.

Energy Technology Data Exchange (ETDEWEB)

In this paper, we study the effect of the Ge{sup +} preamorphization dose on boron diffusion and on the thermal evolution of end of range (EOR) defects during annealing. Amorphizations were carried out by implanting Ge{sup +} at 150 keV to doses ranging from 1x10{sup 15} to 8x10{sup 15} ions/cm{sup 2}. Boron was subsequently implanted at 3 keV with a dose of 1x10{sup 14} ions/cm{sup 2}. Rapid thermal annealing (RTA) was performed for various time/temperature combinations in nitrogen ambient. Secondary ion mass spectroscopy (SIMS) and transmission electron microscopy (TEM) were used to study boron diffusion and defect evolution, respectively. We have found that after a given annealing, both the defect size and boron diffusivity are independent on the Ge ion dose. Increasing this dose only results in an increase of the defect density. These results are discussed and definitely show that EOR ...

International Nuclear Information System (INIS)

We have investigated the correlation between V-shaped defect formation and the optical properties of AlGaN/(In)GaN multiple quantum wells (MQWs) grown under different growth conditions and then demonstrated the characteristics of fabricated ultraviolet (UV) light emitting diodes (LEDs). From the temperature-dependent photoluminescence (PL) measurement, the internal quantum efficiency for 300 K was obtained as 43.6% for a sample with a low density of V-defects in a MQW and 13.7% for a sample with a high density of V-defects. The carrier lifetime based on the time resolved PL measurement at room temperature was 0.32 ns for a sample with a high density of V-defects and 1.26 ns for a sample with a low density of V-defects. And we also found that the density of V-defects affected the external quantum efficiency and wall plug efficiency of the fabricated UV LEDs. ...

British Library Electronic Table of Contents (United Kingdom)

Abstract The glycosylation profile of therapeutic antibodies is routinely analyzed throughout development to monitor the impact of process parameters and to ensure consistency, efficacy, and safety for clinical and commercial batches of therapeutic products. In this study, unusually high levels of the mannose-5 (Man5) glycoform were observed during the early development of a therapeutic antibody produced from a Chinese hamster ovary (CHO) cell line, model cell line A. Follow up studies indicated that the antibody Man5 level was increased throughout the course of cell culture production as a result of increasing cell culture medium osmolality levels and extending culture duration. With model cell line A, Man5 glycosylation increased more than twofold from 12% to 28% in the fed-batch process...

British Library Electronic Table of Contents (United Kingdom)

In many species social behaviors are dependent on integration of chemosensory and hormonal cues. Many chemosensory stimuli are detected by the vomeronasal organ, which projects to many regions that contain steroid receptors, including the medial amygdala. In male hamsters, testosterone is known to acutely increase in response to chemosensory stimulation, and can facilitate sexual behavior by direct action within the medial amygdala. Conspecific stimuli activate the anterior (MeA) and posterior (MeP) medial amygdala, while heterospecific stimuli activate only MeA. Chemosensory stimuli with different social significance differentially activate the dorsal and ventral subdivisions of MeA and MeP. Therefore, it is likely that steroids differentially facilitate stimulation of the medial amygdala...

British Library Electronic Table of Contents (United Kingdom)

Abstract One of the most significant problems in industrial bioprocessing of recombinant proteins using engineered mammalian cells is the phenomenon of cell line instability, where a production cell line suffers a loss of specific productivity (qP). This phenomenon occurs with unpredictable kinetics and has been widely observed in Chinese hamster ovary (CHO) cell lines and with all commonly used gene expression systems. The underlying causes (both genetic and physiological) and the precise molecular mechanisms underpinning cell line instability have yet to be fully elucidated, although recombinant gene silencing and loss of recombinant gene copies have been shown to cause qP loss. In this work we have investigated the molecular mechanisms underpinning qP instability over long-term sub-cult...

International Nuclear Information System (INIS)

A magnetic measuring technique, which sorts out defects according to a distribution function n, was used to study the influence of electron irradiation on 50-50 NiFe. The distribution function is determined in terms of the maximum force f/subm/ that a defect can exert on a forward moving domain wall, or equivalently, the range z_0, which is the distance the mean position of the wall may move past the defect before the wall snaps free from the pinning action of the defect. The range and maximum force are related by a spring constant k, viz., f/subm/=kz_0. The quantity n (z_0) dz_0 gives the number of defects per unit volume having a range between z_0 and z_0+dz_0. Distribution functions were determined before and after electron irradiation. The irradiation was for 100 min with 18-MeV electrons with a dose of 1.1times10"1"7 e/cm"2. Following irradiation, there was a substantial ...

Science.gov (United States)

The bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA) are anatomically connected sites necessary for chemosensory regulation of social behaviors in rodents. Prairie voles (Microtus ochrogaster) are a valuable model for studying the neural regulation of social behaviors because, unlike many other rodents, they are gregarious, pair bond after copulating, and are biparental. We herein describe sex and species differences in immunoreactivity for tyrosine hydroxylase (TH), the rate-limiting enzyme for catecholamine synthesis, in the BST and MeA. Virgin male prairie voles had a large number of TH-immunoreactive cells in areas analogous to the rat principal nucleus of the BST (pBST) and the posterodorsal medial amygdala (MeAPd). Virgin female prairie voles had far fewer TH-immunoreactive cells in these sites ( approximately 17% of the number of cells as males in the pBST, approximately 35% of the number of cells in the MeAPd). A few TH-immunoreactive cells were found in ...

Energy Technology Data Exchange (ETDEWEB)

A set of equations describing a stress-mediated evolution of the nonequilibrium dopant-defect system has been derived and analyzed. Together with coupled diffusion of dopant atoms and point defects, we consider the drift of all mobile species in different charge states, namely vacancies, self-interstitials, and pairs 'dopant atom-point defect', in the field of stress. It has been shown that stresses may affect the diffusion of dopant atoms mainly in two ways: (1) directly, due to the drift of the pairs in the field of stress; (2) indirectly, by the formation of nonuniform defect distribution due to the drift of point defects. On this basis, various features of doping processes, such as phenomena of 'uphill' impurity diffusion near the surface (within the framework of the first or second mechanisms) and the peculiarities of high concentration ...

Energy Technology Data Exchange (ETDEWEB)

(001) CZ silicon wafers were implanted with arsenic (As{sup +}) at energies of 10--50 keV to doses of 2 {times} 10{sup 14} to 5 {times} 10{sup 15}/cm{sup 2}. All implants were amorphizing in nature. The samples were annealed at 700 C for 16 hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of factors including ...

Energy Technology Data Exchange (ETDEWEB)

Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak ...

International Nuclear Information System (INIS)

At the importance increase of UT (ultrasonic testing) with the application of rules on fitness-for-service for nuclear power plants, JAPEIC (Japan power engineering and inspection corporation) started education training for defect detection and sizing technique. Weld joints specimen with EDM (Electro-Discharged Machining) notches, fatigue cracks and intergranular stress corrosion cracks were tested and practiced repeatedly based on a modified ultrasonic method and the defect size measuring accuracy of the trainees was surely improved. Results of the blind test confirmed effectiveness of education training. (T. Tanaka)

CERN Document Server

In situ optical absorption spectroscopy was used to study the generation of E' centres in amorphous SiO_2 occurring by photo-induced breaking of Si-H groups under 4.7eV pulsed laser radiation. The dependence from laser intensity of the defect generation rate is consistent with a two-photon mechanism for Si-H rupture, while the growth and the saturation of the defects are conditioned by their concurrent annealing due to reaction with mobile hydrogen arising from the same precursor. A rate equation is proposed to model the kinetics of the defects and tested on experimental data.

Energy Technology Data Exchange (ETDEWEB)

Transient Enhanced Diffusion (TED) is one of the biggest modeling challenges present in predicting scaled technologies. Damage from implantation of dopant ions changes the diffusivities of the dopants and precipitates to form complex extended defects. Developing a quantitative model for the extended defect behavior during short time, low temperature anneals is a key to explaining TED. This paper reviews some of the modeling developments over the last several years, and discusses some of the challenges that remain to be addressed. Two examples of models compared to experimental work are presented and discussed.

Environmental Research Database

ObjectivesObjectives Not AvailableDescriptionTo determine the effects of water penetration on the burst strength of filament wound composite pipes which have been damaged by impact and then subjected to long term pressurisation with sea water. ~%~ To monitor and characterise the damage and effects of sea water penetration using ultrasonic NDT. To determine the burst strength of bonded composite pipe joints with and without defects and to see whether the defects can be detected using ultrasonic NDT. [continued...

Energy Technology Data Exchange (ETDEWEB)

This study presents results from Monte Carlo radiation transport calculations aimed at characterizing a novel methodology being developed to detect partial defects in Pressurized Water Reactor (PWR) spent fuel assemblies (SFAs). The methodology uses a combination of measured neutron and gamma fields inside a spent fuel assembly in an in-situ condition where no movement of the fuel assembly is required. Previous studies performed on single isolated assemblies resulted in a unique base signature that would change when some of the fuel in the assembly is replaced with dummy fuel. These studies indicate that this signature is still valid in the in-situ condition enhancing the prospect of building a practical tool, Partial Defect Detector (PDET), which can be used in the field for partial defect detection.

International Nuclear Information System (INIS)

Defect cluster formation in 14-MeV neutron irradiated polycrystalline copper has been observed by transmission electron microscopy (TEM) and correlated with the increase in yield stress. The measurements indicate that the radiation hardening component of the yield strength in polycrystals is not directly additive to the unirradiated yield strength. A transitional behavior was observed for radiation hardening at low fluences, which produces an anomalous variation of the defect cluster barrier strength with fluence. The behavior is attributed to the effect of grain boundaries on slip band transmission. An upper limit for the room temperature barrier strength of defect clusters in neutron-irradiated copper was determined to be #alpha#=0.23. (orig.).

British Library Electronic Table of Contents (United Kingdom)

This paper introduces the application of independent component analysis mixture modelling (ICAMM) in non-destructive testing (NDT). The application consists of discriminating patterns for material quality control from homogeneous and defective materials inspected by impact-echo testing. This problem is modelled as a mixture of independent component analysis (ICA) models, representing a class of defective or homogeneous material by an ICA model whose parameters are learned from the impact-echo signal spectrum. These parameters define a kind of particular signature for the different defects. The proposed procedure is intended to exploit to the maximum the information obtained with the cost efficiency of only a single impact. To illustrate this capability, four levels of classification detail...

UK PubMed Central (United Kingdom)

The tetrapeptide KDEL is commonly found at the C terminus of soluble proteins of the endoplasmic reticulum (ER), and it contributes to their localization by interacting with a receptor that recycles...Full Text Available

Science.gov (United States)

Giant magnetoresistance (GMR) has been used with Eddy current testing to detect small defects not only in thin film structures but also in multilayered metallic structures. This work detected small scratches in the thin film under the surface where these defects were unable to be inspected or monitored by regular testing. In addition, rotational GMR magnetic sensor based Eddy current probes were used for detecting buried corner cracks at the edge of holes in metallic structures. The results of this study proved that giant magnetoresistance is very powerful and effective to sense the magnetic field, which is the result from the perturbation of the Eddy currents caused by a defect. This method can be used for quality control of metallization layers on silicon wafer and to detect cracks in thick structures such as cracks in aging aircraft.

UK PubMed Central (United Kingdom)

Mutation of the gene drop-dead (drd) causes adult Drosophila to die within 2 weeks of eclosion and is associated with reduced rates of defecation...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

To study the defect creation induced by electronic processes in refractory oxides, MgO single crystals were irradiated with high energy tin, uranium and lead ions. Optical absorption measurements showed that F-type centers (oxygen vacancies with trapped electrons) were created during irradiation. The total number of centers per unit area of bombarded sample increases linearly with irradiating fluence. The main part of the point defects was found to arise from electronic processes. The concentration of F-type centers induced by ionization increases with the electronic energy losses. Assuming a saturation of point defect concentration at high fluences, F-type center creation cross sections could be estimated. The influence of irradiation temperature and of the velocity of the bombarding ions are discussed.

Science.gov (United States)

... company. To automate this initial cutup requires a computer vision system that can locate and identify surface defects ... ...

Energy Technology Data Exchange (ETDEWEB)

The magnetic susceptibility of GaAs samples containing a large concentration of native defects was investigated by dc magnetization measurements. Thin GaAs films grown by molecular-beam epitaxy at very low temperatures and bulk GaAs:S samples irradiated with fast neutrons have been studied. For all samples, the susceptibility follows a Curie-Weiss law, indicating the presence of localized magnetic moments. These moments are attributed to unpaired spins located at the native defects. Negative Curie-Weiss temperatures found for both neutron-irradiated and low-temperature-grown GaAs is a clear manifestation of an antiferromagnetic interaction between the moments. The presence of a highly inhomogeneous distribution of native defects has to be assumed to account for the observed antiferromagnetic ordering.

Energy Technology Data Exchange (ETDEWEB)

Removal of sulfonamide (SAs) and tetracycline (TAs) classes of antibiotic compound from deionized water and DOC water by powdered activated carbon (PAC) adsorption was evaluated in this study. According to the study results, TAs were more easily adsorbed than SAs although TAs were more hydrophilic than SAs. The phenolic compounds in TAs might be responsible for their high adsorption. Complex formation of TAs with metal and metal oxide on the surface of activated carbon might also contribute to higher adsorption. The hydrophobic effect was important for removal of SAs. More hydrophobic SAs were removed more easily. The carbon type was not important for adsorption of SAs and TAs. Coal based carbon and coconut based carbon showed similar removal efficiencies for these antibiotics. Dissolved organic materials interfered with adsorption of SAs and TAs. Organic interference was more significant for the antibiotic compound, which was more subject to the PAC adsorption. ...

International Nuclear Information System (INIS)

The Rocky Flats Environmental Technology Site (RFETS) has historically released radionuclide chemicals of potential concern into the surrounding environment. The off-site environment was evaluated for Pu"2"3"9"/"2"4"0 and Am"2"4"1 occurrence. An evaluation of exposure and effects to the aquatic ecology within off-site areas including: Standley Lake, Great Western Reservoir, Mower Reservoir and portions of Big Dry Creek, Walnut Creek, and Woman Creek was performed for the completion of an Ecological Risk Assessment. Collocated sampling activities were performed for surface water, sediment, benthic macroinvertebrates and fish. Results of the analytical data were used to assess ongoing exposure and effects. Data collected to determine effects (chemical content of fish tissue, diversity and density of macroinvertebrate populations) provided some of the necessary information needed to evaluate risk. However, due to conditions of interfering stressor effects, a ...

Energy Technology Data Exchange (ETDEWEB)

Fitness, (biometric measurements, reproduction) and behaviour that are ecologically relevant biomarkers in assessing the quality of estuarine sediments were studied by comparing the responses of the polychaete worm Nereis diversicolor - a key species in estuaries - along a pollution gradient. Intersite differences were shown for all the measured parameters: size-weight relationships, energy reserves as glycogen and lipids, sexual maturation patterns, total number of oocytes per female, total and relative fecundity, burrowing behaviour. The physiological and behavioural status of N. diversicolor was consistently disturbed in the larger, most contaminated estuaries (Loire and Seine, Fr.) compared to reference sites (Bay of Bourgneuf, Goyen estuary, Fr.). Many classes of potentially toxic chemicals present in these estuaries most likely contribute to these impairments but food availability may act as a confounding factor, interfering with the potential impact of ...

Energy Technology Data Exchange (ETDEWEB)

A sensitive and rapid automated method has been developed for the selective analysis of acid extractable sulfide in environmental samples by combining gas dialysis separation techniques with methylene blue detection procedures. Acid extractable sulfide is separated from the sample matrix by the gas dialysis membrane and subsequently trapped in a dilute sodium hydroxide receiving stream. This stream is reacted with N,N-dimethyl-p-phenylenediamine and ferric chloride to produce methylene blue which is then quantitated colorimetrically at 660 nm. For standards and nonturbid environmental samples, there is good agreement between the results obtained by this procedure and the standard methylene blue method. The effect of interferences on the accurate determination of sulfide by both methods was also examined and it was found that cupric ions significantly interfered with sulfide estimation. To obtain adequate sulfide recoveries in tap water and environmental samples ...

British Library Electronic Table of Contents (United Kingdom)

Aims: In this study we investigated whether attenuation of endoplasmic reticulum stress (ER stress) could protect HepG2 cells from free fatty acid (FFA)-induced apoptosis. Main methods: Human liver cell line HepG2 cells were exposed to Sodium Palmitate (Pa) or Sodium Oleate (Ol). Apoptosis and ER stress of HepG2 cells were analyzed with flow cytometry, real-time RT-PCR and Western Blotting. An expression plasmid encoding for the ER chaperone immunoglobulin heavy chain-binding protein (Bip) was transfected into HepG2 cells to attenuate ER stress. Small interfering RNA siCHOP was used to knockdown the expression of C/EBP Homologous Protein (CHOP) in HepG2. Key findings: Pa led to cytotoxicity and apoptosis in HepG2 cells in a dose-dependent pattern and also induced ER stress indicated by inc...

Energy Technology Data Exchange (ETDEWEB)

Investigations of sucrose synthase in maize root tips have required development of a means to circumvent the rapid decline of activity observed after extraction dialysis and either synthetic or degradative assays. Several protease inhibitors were tested; although PMSF increased initial activity, no inhibitor prevented the drop in activity with time. Western blot analysis indicated that activity decline was not associated with protein degradation. Therefore, a procedure was developed which (1) shortened extraction-to-assay period from ca. 24 hours to 7 minutes, (2) simplified previous assays and (3) reduced the amount of tissue required. Extract was desalted with spun columns and the {sup 14}C-UDPG product recovered with DEAE ion exchange paper. The minute quantities of product recovered can be concealed by the presence of trace impurities in the {sup 14}C-sucrose utilized. DEAE ion exchange paper was used to remove interfering radio-labelled compounds from the {sup ...

UK PubMed Central (United Kingdom)

Vibrio cholerae 638 (El Tor, Ogawa), a new CTXΦ-negative hemagglutinin/protease-defective strain that is a cholera vaccine candidate, was examined for safety and immunogenicity...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Described herein is an optical probe (120) for use in characterizing surface defects in wafers, such as semiconductor wafers. The optical probe (120) detects laser light reflected from the surface (124) of the wafer (106) within various ranges of angles. Characteristics of defects in the surface (124) of the wafer (106) are determined based on the amount of reflected laser light detected in each of the ranges of angles. Additionally, a wafer characterization system (100) is described that includes the described optical probe (120).

International Nuclear Information System (INIS)

Transient Enhanced Diffusion (TED) of boron in silicon is driven by the large supersaturations of self-interstitial silicon atoms left after implantation which also often lead to the nucleation and subsequent growth, upon annealing, of extended defects. In this paper we review selected experimental results and concepts concerning boron diffusion and/or defect behavior which have recently emerged with the ion implantation community and briefly indicate how they are, or will be, currently used to improve 'predictive simulations' softwares aimed at predicting TED. In a first part, we focus our attention on TED and on the formation of defects in the case of 'direct' implantation of boron in silicon. In a second part, we review our current knowledge of the defects and of the diffusion behavior of boron when annealing preamorphised Si. In a last part, we try to compare these two cases and to find out what are ...

International Nuclear Information System (INIS)

The exafs method is proposed as a more informative, universal one to investigate the radiation defects in solids. The successful results as obtained by the author using the synchrotron radiation source are reported for the first time. The measurements were carried out in GaAsP crystals irradiated with 50 MeV electrons.

CERN Document Server

We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.

UK PubMed Central (United Kingdom)

The bioenergetic capacity of skeletal muscle in a 17-year-old patient with a severe defect in complex III of the electron transport chain has been examined by 31P NMR measurements of the molar ratio...Full Text Available

International Nuclear Information System (INIS)

A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF_2, and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational ...

Energy Technology Data Exchange (ETDEWEB)

Radixin is a cytoskeletal protein that may be important in linking actin to the plasma membrane. Recent cloning of the murine and porcine radixin cDNAs revealed a protein highly homologous to ezrin and moesin. The authors have cloned and sequenced the human radixin cDNA and found the predicted amino acid sequence for the human protein to be nearly identical to those predicted for radixin in the two other species. By Southern analyses of Chinese hamster x human somatic cell hybrid DNA and of PCR products derived from hybrids, the coding gene (RDX) was mapped to 11q. Fluorescence chromosomal in situ hybridization with a cDNA plasmid further localized this gene to band 11q23. However, PCR amplification with [open quotes]radixin-specific[close quotes] primers on the hybrid DNA panel yielded an additional, very similar DNA sequence that was further characterized by direct sequencing of PCR products. This sequence represents a truncated version and the respective locus ...

Energy Technology Data Exchange (ETDEWEB)

RNA interference has become a powerful biological tool over the last decade. In this study, a tetracycline-inducible shRNA vector system was designed for silencing CFP expression and delivered alongside the yfp marker gene into Chinese hamster ovary cells using impalefection on spatially indexed vertically aligned carbon nanofiber arrays (VACNFs). The VACNF architecture provided simultaneous delivery of multiple genes, subsequent adherence and proliferation of interfaced cells, and repeated monitoring of single cells over time. Following impalefection and tetracycline induction, 53.1% 10.4% of impalefected cells were fully silenced by the inducible CFP-silencing shRNA vector. Additionally, efficient CFP-silencing was observed in single cells among a population of cells that remained CFP-expressing. This effective transient expression system enables rapid analysis of gene silencing effects using RNAi in single cells and cell populations.

Energy Technology Data Exchange (ETDEWEB)

The human CDC25 tyrosine phosphatases trigger activation of CDC2 by removing inhibitory phosphates; thus the genes encoding these phosphatases may be suspected as potential oncogenes due to their role in promoting cell division. To date, three human CDC25 genes have been identified: CDC25A, B, and C. This communication describes the mapping of CDC25A to chromosome 3p21 and CDC25B to chromosome 20p13 by fluorescence in situ hybridization with confirmation by the polymerase chain reaction of hamster-human somatic cell hybrid DNA. 3p21 is near an area frequently involved in karyotypic abnormalities in renal carcinomas, small cell carcinomas of the lung, and benign tumors of the salivary gland. 20p13 does not seem to be a common area for karyotypic alteration in tumors. Mapping of these genes to their chromosomal loci may help identify tumors with abnormal regulation of CDC25 genes due to genomic alterations. 15 refs., 3 figs.

Energy Technology Data Exchange (ETDEWEB)

There are currently no accepted industry standards for the tensile strain limits of girth welds. This paper investigated the behavior of girth welds with buried defects subjected to high longitudinal strains caused by soil movement. A strain design methodology based on a crack driving method was used to examine the factors influencing stain limits along with a constraint-sensitive fracture mechanics approach. No strength undermatching was used in the welds, and the defect location had no influence on crack driving force. The weld joint was assumed to have uniform tensile properties. A 3D finite element (FE) model was used to simulate pipe behavior. Symmetric boundary conditions were imposed on the symmetry planes, and uniform remote axial displacement was applied as the primary loading. Automated data processing routines were developed to extract and analyze the data. The crack driving force was computed directly from a crack tip deformation ...

International Nuclear Information System (INIS)

Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generators test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking, and intergranular attack. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different probe types. The computations of the change in instrument reading due to the defects have led to an inversion ...

International Nuclear Information System (INIS)

A series of nine model ferritic alloys were ion irradiated at #propor to#300 C using 2.5 MeV He ions to a dose of 1.4 x 10"2"1 ion/m"2, which corresponds to #propor to#0.1 dpa at a depth of 2 #mu#m and #propor to#3.5 dpa at the peak damage region which occurs at about 4 #mu#m deep. The resultant changes in hardness as a function of depth were measured using a Nanoindenter "t"r"a"d"e"m"a"r"k. TEM was used to investigate the defect distributions. The effect of various solutes, Cu and N in particular, but Mn and Ti as well, on the change of hardness and the defect distribution due to the ion irradiation are discussed. (orig.).

International Nuclear Information System (INIS)

Until a decade ago, only the differential bobbin type eddy current probe was considered necessary for reliable heat exchanger tube inspection. The introduction of different tube materials, manufacturing processes and a variety of service induced failures has greatly increased the demands of eddy current testing. Optimized probe designs enhanced by improved instrumentation can help satisfy some of these demands. Some of the more difficult inspection problems are detection of circumferential cracks, fretting wear under non-ferromagnetic support plates and shallow internal defects. Reliable detection and sizing of such defects is often made more difficult by the fact they frequently occur in defect prone regions such as under tubesheets or support plates and in transition regions of finned tubes. Probe designs effective in overcoming these difficulties exist. This paper describes a number of such probes and their performance.

Energy Technology Data Exchange (ETDEWEB)

With steam generator check testing, the numerous types of defect not only have to be detected reliably but also to be identified correctly and classified according to depth. A priori, no signals are provided by the physical eddy-current mechanism, i.e. the disturbance of an excited eddy-current field by a defect, which will allow unambiguous identification and classification of the defects. The task, therefore, consists in designing the eddy-current method in terms of measurement technology in such a way as to obtain useful detection, identification and classification by a translation of the signals as simple and as save as possible. Internal through-flow wils and internal rotating probes were examined for their suitability to fulfill this three-pronged task with steam generator inspection.

British Library Electronic Table of Contents (United Kingdom)

The treatment of acetabular bone defects presents a great challenge in revision total hip arthroplasty (THA). The purpose of this study was to evaluate the clinical and radiological outcome of revision THA using jumbo cups for acetabular reconstruction after applying the bone-grafting technique. We studied 17?patients with acetabular defects ranging from Type 2A to Type 3A according to Paprosky`s classification. According to the AAOS-score twelve patients were classified as Type II and five patients as Type III. Uncemented press-fit cups with an outer diameter larger than 64?mm were used in all cases. Fifteen patients received morselized bone allografts. In eight patients an additional screw fixation was necessary. The mean follow-up period was 82?months (range 33?149). The mean Harris Hip...

Science.gov (United States)

The authors have studied (Al{sub x}Ga{sub 1{minus}x}){sub 0.5}In{sub 0.5}P doped with tellurium using deep level transient spectroscopy and associated electrical measurements. Several defect states are observed in the upper half of the band gap, that are believed to be intrinsic to the alloy system as well as related to the tellurium donors. Defects observed at measurement temperatures above 390 K exhibit a hysteretic behavior. The observed spectra depend on the biasing conditions applied to the Schottky diode during cooling. The hysteretic behavior suggests the existence of different defect configurations, which can be accessed under conditions of high temperatures and electrical stress, but remain stable below 300 K.

Energy Technology Data Exchange (ETDEWEB)

The electrochemical performances of orthorhombic LiMnO{sub 2} compounds are analyzed in order to find a structural and/or morphological origin to the differences of electrochemical behaviours observed in compounds with different size of crystallites and different amounts of lattice defects. Energy capacity performances of 200 Ah/kg are reached for materials with crystallites of about 10{sup 7} Angstrom{sup 3} and with about 7% of defects, while energy capacities of only 80 Ah/kg are obtained for materials with ten times bigger crystallites. (J.S.) 3 refs.

Energy Technology Data Exchange (ETDEWEB)

Large single crystals of PETN, RDX, and TNT can be grown easily from evaporating ethyl acetate solutions. The crystals all share a similar type of defect that may not be commonly recognized. The defect generates conical faces ideally mosaic crystals, and may account for the ``polymorphs`` of TNT and detonator grades of PETN. TATB crystals manufactured by the amination of trichlorotrinitrobenzene in dry toluene entrain two forms of ammonium chloride. One of these forms causes ``worm holes`` in the TATB crystals that may be the reason for its unusually low failure diameters. Strained HMX crystals form mechanical twins that can spontaneously revert back to the untwinned form when the straining force is removed. Large strains or temperatures above 100{degrees}C lock in the mechanical twins.

Energy Technology Data Exchange (ETDEWEB)

The trend toward smaller dimensions in integrated circuit technology presents severe physical and engineering challenges for ion implantation. These challenges, together with the need for physically-based models at exceedingly small dimensions, are leading to a new level of understanding of fundamental defect science in silicon. Recently the DOE Council on Materials requested that our panel examine the current status and future research opportunities in the area of ion beams in semiconductor processing. Particularly interesting are the emerging approaches to defect and dopant distribution modeling, transient enhanced diffusion, high energy implantation and defect accumulation, and metal impurity gettering. These topics were explored both from the perspective of emerging science issues and technology challenges.

Energy Technology Data Exchange (ETDEWEB)

Problems can sometimes occur during the construction of cast in-situ concrete piles. These foundations are formed by drilling a substantial hole into the ground and subsequently filling it with steel reinforcement and wet concrete. Several well-documented cases exist where concrete has not filled the hole and substantial voids have been left in the apparently completed pile. A theory has been developed by which it is possible to identify the nature, size and position of a finite defect within a suspect pile. The technique is based on the concept of receptances, and requires information obtained from vibration tests performed on piles after the concrete has hardened, and the nominal dimensions and material properties of the pile. The application of the theory is demonstrated using data relating to a pile with a known defect. The theory described in this paper ignores the effect of the surrounding soil; this can be included by further development ...

Energy Technology Data Exchange (ETDEWEB)

A review of the deep-level defects observed in both electron- and proton-irradiated GaAs solar cells is presented. Studies of the effects of periodic and continuous thermal annealing on the radiation-induced electron and hole traps and the recombination parameters in GaAs solar cells were made for a wide range of electron and proton energies, fluence, annealing temperature and annealing time. A refined model for numerical simulations of the displacement damage was developed for computing the defect density and the cell parameters in the electron- and proton-irradiated GaAs solar cells. Excellent agreement was obtained between the calculated values and the experimental data for the proton-irradiated GaAs solar cells. (orig.).

International Nuclear Information System (INIS)

The magnetic hyperfine constants of the V sub(K) center in CaF_2, SrF_2 and BaF_2 have been calculated, assuming a phenomenological model, based on the F"-_2 'central molecule', to describe the wave function of the defect. The introduction of covalence with the ions neighboring the 'central molecule', has shown that this is a better description for the defect than a simple 'central molecule' model. It was also shown that the results for the hyperfine constants are strongly dependent on the relaxations of these neighboring ions, which have been determined by fitting the experimental data. The present results are compared with other previous calculations where similar and different methods have been used. A better description for the wave function of the defect is suggested. (author).

UK PubMed Central (United Kingdom)

Although recent data established that a specific very-long-chain fatty acyl-CoA synthetase is defective in X-linked adrenoleukodystrophy (ALD), the ALD gene is still unidentified. The ALD locus has...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Transient enhanced diffusion (TED) of boron in silica after low energy boron implantation and annealing was investigated using boron-doping superlattices (DSLs) grown by low temperature molecular beam epitaxy. Boron ions were implanted at 5, 10, 20, and 40 keV at a constant dose of 2{times}10{sup 14}/cm{sup 2}. Subsequent annealing was performed at 750{degree}C for times of 3 min, 15 min, and 2 h in a nitrogen ambient. The broadening of the boron spikes was measured by secondary ion mass spectroscopy and simulated. Boron diffusivity enhancement was quantified as a function of implant energy. Transmission electron microscopy results show that {l_angle}311{r_angle} defects are only seen for implant energies {ge}10 keV at this dose and that the density increases with energy. DSL studies indicate the point defect concentration in the background decays much slower when {l_angle}311{r_angle} defects are present. These results ...

UK PubMed Central (United Kingdom)

Genetic defects in the dystrophin-associated protein complex (DAPC) are responsible for a variety of pathological conditions including muscular dystrophy, cardiomyopathy, and vasospasm. Conserved DAPC...Full Text Available

UK PubMed Central (United Kingdom)

Normal brain development requires a series of highly complex and interrelated steps. This process presents many opportunities for errors to occur, which could result in developmental defects...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A system of equations describing transient enhanced diffusion of beryllium in InGaAs due to kick-out mechanism or due to formation, migration, and dissociation of the pairs ''beryllium atom-group III self-interstitial'' is proposed and analyzed. Simulation of coupled diffusion of beryllium atoms and self-interstitials in InGaAs during rapid thermal annealing was done for the case of dual implantation. For the experiment under consideration the first ion implantation of phosphorus atoms produced the region of extended defects that led to ''uphill'' diffusion of implanted Be in the defect region and in the vicinity of the surface. The suggested reason of ''uphill'' diffusion could be related to the nonuniform distribution of group III self-interstitials that was formed due to the absorption of point defects on the ...

UK PubMed Central (United Kingdom)

The properties of an atypical Brucella strain isolated from lymph node tissue of a cow slaughtered as a brucellosis reactor were examined. The organism was Gram negative and highly pleomorphic, existing...Full Text Available

UK PubMed Central (United Kingdom)

Platelet-derived growth factor (PDGF) is a potent moderator of soft tissue repair through induction of the inflammatory phase of repair and subsequent enhanced collagen deposition. We examined the effect...Full Text Available

UK PubMed Central (United Kingdom)

Cancer cells constantly adapt to oxidative phosphorylation (OXPHOS) suppression resulting from hypoxia or mitochondria defects. Under the OXPHOS suppression, AMP-activated protein kinase (AMPK) regulates...Full Text Available

UK PubMed Central (United Kingdom)

We report on the presentation and management of a patient with herniation of the rectum following a coccygectomy. We used an abdominal approach and careful pelvic dissection to define the defect in...Full Text Available

International Nuclear Information System (INIS)

Ion implantation of Si (60 keV, 1x10"1"4/cm"2) has been used to introduce excess interstitials into silicon predoped with high background concentrations of B, which were varied between 1x10"1"8 and 1x10"1"9/cm"3. Following post-implantation annealing at 740 degree C for 15 min to allow agglomeration of the available interstitials into elongated #left brace#311#right brace# defects, the density of the agglomerated interstitials was determined by plan-view transmission electron microscopy observation of the defects. We report a significant reduction in the fraction of excess interstitials trapped in #left brace#311#right brace# defects as a function of boron concentration, up to nearly complete disappearance of the #left brace#311#right brace# defects at boron concentrations of 1x10"1"9/cm"3. The reduction of the excess interstitial concentration is interpreted in terms of boron-interstitial clustering, ...

UK PubMed Central (United Kingdom)

BackgroundA strong association between stress resistance and longevity in multicellular organisms has been established as many mutations that extend lifespan also show increased...Full Text Available

UK PubMed Central (United Kingdom)

We developed mice with germline endogenous expression of oncogenic Hras to study effects on development and mechanisms of tumor initiation. They had high perinatal mortality, abnormal...Full Text Available

UK PubMed Central (United Kingdom)

Japanese medaka (Oryzias latipes) embryos exposed to ethanol have developed craniofacial, cardiovascular and skeletal defects which can be compared with the phenotypic features...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The characteristics of defects induced by Si and Ga focused ion beam (FIB) implantation in n-GaAs have been investigated by means of deep-level transient spectroscopy (DLTS), C--V carrier profiling, and resistance measurements. The DLTS spectra of Si and Ga FIB implanted samples annealed at temperatures up to 500 /sup 0/C are apparently identical to one another and show three different electron traps with an activation energy between 0.25 and 0.6 eV. The resistance increases by more than five orders of magnitude by Si and Ga FIB implantation due to the induced defects. However, it is restored to initial values after annealing at 600 /sup 0/C, except for a sample of Ga implantation with a dose higher than 10/sup 14/ cm/sup 2/ . For annealing of induced defects, there are no intrinsic problems for FIB implantation with a dose lower than 10/sup 13/ cm/sup 2/ .

UK PubMed Central (United Kingdom)

mRNA is sequestered and turned over in cytoplasmic processing bodies (PBs), which are induced by various cellular stresses. Unexpectedly, in Saccharomyces cerevisiae, mutants of the...Full Text Available

UK PubMed Central (United Kingdom)

Lymphocytes from patients with insulin-dependent diabetes mellitus (IDDM), a chronic autoimmune disease, have recently been shown to have decreased surface expression of MHC class I antigens. Since...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In the present study, the type and densities of defects in AlN crystals grown on 6H-SiC seeds by the sublimation-recombination method were assessed. The positions of the defects in AlN were first identified by defect selective etching (DSE) in molten NaOH-KOH at 400 C for 2 minutes. Etching produced pits of three different sizes: 1.77 m, 2.35 m , and 2.86 m. The etch pits were either aligned together forming a sub-grain boundary or randomly distributed. The smaller etch pits were either isolated or associated with larger etch pits. After preparing crosssections of the pits by the focused ion beam (FIB) technique, transmission electron microscopy (TEM) was performed to determine which dislocation type (edge, mixed or screw) produced a specific etch pit sizes. Preliminary TEM bright field and dark field study using different zone axes and diffraction vectors indicates an edge dislocation with a Burgers vector 1/3[1120] is ...

Energy Technology Data Exchange (ETDEWEB)

Transient-enhanced diffusion (TED) during thermal annealing of ion-implanted B in Si is well established and attributed to the ion-induced, excess interstitials. On the other hand, the mechanism to account for TED of B in preamorphized (PA) Si remains unclear. Enhanced diffusion of the B persists in regrown layers even though the ion-induced interstitial defects responsible for TED in B{sup +}-only implanted Si are eliminated following regrowth. To test the hypothesis that TED in PA Si results from the {open_quotes}excess{close_quotes} interstitial-type defects below the amorphous-crystalline (a-c) interface, a buried PA layer has been recrystallized from the surface inward to the SiO{sub 2} interface of silicon-on-insulator material to eliminate all possible sources of excess interstitials. The effect on B diffusion and the role of the residual interstitial-type defects will be discussed. {copyright} {ital 1999 American ...

UK PubMed Central (United Kingdom)

In a previous study we found that nanofibrous poly(l-lactic acid) (PLLA) scaffolds mimicking collagen fibers in size were superior to solid-walled scaffolds in promoting osteoblast differentiation...Full Text Available

UK PubMed Central (United Kingdom)

Molecular chaperones protect cells from the deleterious effects of protein misfolding and aggregation. Neurotoxicity of amyloid-beta (Aβ) aggregates and their deposition in senile plaques are...Full Text Available

UK PubMed Central (United Kingdom)

SUMMARYAmeloblastin (AMBN) is the second most abundant extracellular matrix protein produced by the epithelial cells called ameloblasts and is found mainly in forming dental enamel....Full Text Available

CERN Document Server

We point out that the moduli sector of the $(2,2)$ string compactification with its nonperturbatively preserved non-compact symmetries is a fertile framework to study global topological defects, thus providing a natural source for the large scale structure formation. Based on the target space modular invariance of the nonperturbative superpotential of the four-dimensional N=1 supersymmetric string vacua, topologically stable stringy domain walls are found. They are supersymmetric solutions, thus saturating the Bogomolnyi bound. It is also shown that there are moduli sectors that allow for the global monopole-type and texture-type configurations whose radial stability is ensured by higher derivative terms.

Energy Technology Data Exchange (ETDEWEB)

The defects localization in power cables follows several steps: identification, pre-localization and precise localization. Pre-localization methods, other than echo-metry, are presented first: bridge methods, particular case of low voltage networks, future perspectives. Then, the precise localization methods are described: magneto-acoustic method, audible frequencies method. The particular case of underwater and high-voltage cables is considered too (oil and gas leaks detection). (J.S.)

Energy Technology Data Exchange (ETDEWEB)

Magnetic behavior in three compounds RTa{sub 3}O{sub 9} (R = Nd, Eu and Ho) with defect-perovskite structures has been investigated by DC magnetic susceptibility. The susceptibility of NdTa{sub 3}O{sub 9} shows strong influence of crystal field. For EuTa{sub 3}O{sub 9} a typical Van Vleck paramagnetism has been observed. HoTa{sub 3}O{sub 9} obeys a Curie-Weiss law above 20 K. (orig.) 8 refs.

Energy Technology Data Exchange (ETDEWEB)

This study deals with the application of wavelet analysis to detection and characterization of defects from eddy-current and ultrasonic testing signals of a low signal-to-noise ratio. Presented in this paper are the methods for processing eddy-current testing signals of heat exchanger tubes of a steam generator in a nuclear power plant. The results of processing eddy-current testing signals of tube test pieces with artificial flaws show that the flaw signals corrupted by noise and/or non-defect signals can be effectively detected and characterized by using the wavelet methods. (author)

International Nuclear Information System (INIS)

To evaluate the radiological patterns of vascular invasion in peripheral cholangiocarcinomas. Hepatic arteriography and portography in 20 cases with cholangiocarcinoma including 12 cases with angiographic CT were retrospectively analyzed. The arteriography showed no arterioportal shunt, hypertrophy of tumor vessel, or tumor staining extending to central portion of the mass in all cases. However, doughnut shaped peripheral tumor staining was seen until late hepatogram phase in 12 cases and compensatory hyperperfusion around the mass was seen in six cases (eight cases if include arterial CT). Encasement of tumor vessel was seen in 12 cases, and hypertrophy of feeding vessel in nine cases. On portography, the filling defect on segmental portal branch could be demonstrated only in 11 cases. Shape of the portal defect was tapered narrowing in six cases, abrupt narrowing in two cases but intraluminal nodular filling defect was ...

Energy Technology Data Exchange (ETDEWEB)

The evaluation of possible manufacture-based defects in turbine shafts and housings for component serviceability relevance is of particular interest not only in post-manufacturing NDT but also in evaluation of NDT results obtained by in-service inspections of components with long service lives. The results discussed in the paper are summarized as follows: Most of the examined natural defects in the forgings and castings behave like cracks under the simulated operating conditions and hence may well be evaluated by fracture mechanical methods for their serviceability relevance determined by crack propagation under fatigue, creep and creep-fatigue stress. The empirical correlation of true defect size and US testing results (echo signal, echodynamics, attenuation) permits improved determination of true defect sizes in the turbine components. Care has to be taken to select the proper testing and evaluation ...

Science.gov (United States)

In this study, we investigated the effects of one- and two-staged orchiopexy on testicular volume and serum testosterone levels in cases with high, abdominally localized, bilateral nonpalpable testes. Between March 1996 and April 2001, orchiopexy was performed on 46 testes in 23 patients with bilateral nonpalpable testes. In 15 of the 23 patients, a two-stage Fowler-Stephens orchiopexy was performed, and in 8 of the 23 patients, a one-stage laparoscopic orchiopexy was performed. For one patient who lacked both testes, bilateral prosthetic testes were inserted. The patients' ages were between 20 and 23 years (average, 21 years). In the first stage of the two-stage orchiopexy, the spermatic artery was ligated laparoscopically. Six months later, open surgery orchiopexy was performed. Patients were followed for 2 to 16 months (average, 10 months) and were evaluated for testicular atrophy, serum testosterone levels, and complications. In all the patients, the preoperative secondary sexual ...

International Nuclear Information System (INIS)

Sodium monofluoroacetate (1080) is a vertebrate pesticide widely used for possum control in New Zealand. Fluoroacetate is also a toxic component of poisonous plants found in Australia, South Africa, South America, and India. Because of its importance and effectiveness in pest control and the highly toxic nature of this compound, its acute sub-lethal and target organ toxicity have been extensively studied. In relation to its use as a pesticide its environmental fate, persistence, non-target impacts and general toxicology have been and continue to be extensively studied. Toxic baits must be prepared and used with extreme care, otherwise humans, livestock, and non-target wildlife will be put at risk. The high risk of secondary poisoning of dogs is a cause for concern. 1080 acts by interfering with cellular energy production. Possums die from heart failure, usually within 6-18 h of eating baits. Long-term exposure to sub-lethal doses can have harmful effects and strict ...

International Nuclear Information System (INIS)

Magnetization of R_2CuO_4 (R=Y, Dy, Ho, Er, Tm) crystallizing in the Nd_2CuO_4-type (T') structure has been measured between 4 and 300 K. In Y_2CuO_4 antiferromagnetic ordering of Cu"2"+ spins at 260 K has been detected clearly, without being interfered with by the paramagnetic contribution of rare-earth elements as in the other compositions. Weak ferromagnetic behavior with a moment of 9x10"-"4 #mu#_B/Cu accompanies the antiferromagnetic transition. Dy"3"+, Ho"3"+, Er"3"+, and Tm"3"+ ions obey the Curie-Weiss law at relatively high temperatures, and the effective moments are in good agreement with the values anticipated from their lowest multiplet levels. Various types of deviations from the law occur at low temperatures. Specifically, a sharp kink possibly suggesting antiferromagnetic ordering of the Dy"3"+ moments has been found at 7 K. Anomalies around 200 K for Ho_2CuO_4 and Er_2CuO_4 reflect the weak ferromagnetic contribution of the CuO_2 lattice.

International Nuclear Information System (INIS)

The TESLA Test Facility (TTF) at DESY is a facility producing sub-picosecond electron pulses for the generation of VUV or soft X-ray radiation in a free electron laser (FEL). The same electron pulses would also allow the direct production of high-power coherent radiation by passing the electron beam through an undulator. Intense, coherent far-infrared (FIR) undulator radiation can be produced from electron bunches at wavelengths longer than or equal to the bunch length. The source described in this paper provides, in the wavelength range 50-300 #mu#m, a train of about 1-10 ps long radiation pulses, with about 1 mJ of optical energy per pulse radiated into the central cone. The average output power can exceed 50 W. In this conceptual design, we intend to use a conventional electromagnetic undulator with a 60 cm period length and a maximum field of 1.5 T. The FIR source will use the spent electron beam coming from the VUV FEL which allows one to significantly extend the scientific ...

Energy Technology Data Exchange (ETDEWEB)

Transient Enhanced Diffusion (TED) of dopants in Si is the consequence of the evolution, upon annealing, of a large supersaturation of Si self-interstitial atoms left after ion bombardment. In the case of amorphizing implants, this supersaturation is located just beneath the c/a interface and evolves through the nucleation and growth of End-Of-Range (EOR) defects. For this reason, the authors discuss here the relation between TED and EOR defects. Modelling of the behavior of these defects upon annealing allows one to understand why and how they affect dopant diffusion. This is possible through the development of the Ostwald ripening theory applied to extrinsic dislocation loops. This theory is shown to be readily able to quantitatively describe the evolution of the defect population (density, size) upon annealing and gives access to the variations of the mean supersaturation of Si self-interstitial ...

International Nuclear Information System (INIS)

A set of advanced models implemented into the simulator Sentaurus Process was applied to simulate ultra shallow junction formation by flash lamp annealing (FLA). The full path transient enhanced diffusion model includes equations for small interstitial clusters (I_2, I_3, I_4), #left brace#3 1 1#right brace# defects and dislocation loops. A dopant-point defect clustering model is used for dopant activation simulation. Several cluster types are considered: B_2, B_2I, B_2I_2, B_3I, B_3I_2, B_3I_3 for boron and As_2, As_2V, As_3, As_3V, As_4, As_4V for arsenic. Different point defect and dopant-point defect pair charge states are taken into account to obtain accurate results in the high doping level region. The flux expressions in the three-phase segregation model include a dependence on the doping level and point defect supersaturation. The FLA process was performed at various peak ...

Energy Technology Data Exchange (ETDEWEB)

A comparison of the concentration-response effects of inhaled ozone (O/sub 3/) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation studies of this gas. The effect of 4-hour exposure to ozone (O/sub 3/) at concentrations of 0.0, 0.2, 0.5, 1.0, and 2.0 ppm was determined in rabbits, guinea pigs, rats, hamsters and mice. Lavage fluid protein (LFP) accumulation 18 hr after exposure was used as the indicator of O/sub 3/-induced pulmonary edema. All species had similar basal levels of LFP (250-350 ug/ml) when a volume of saline which approximated the total lung capacity was used for lavage of the collapsed lungs. Exponential dose-response curves were seen in all species except guinea pigs, which showed significant increases in LFP at low O/sub 3/ concentrations (0.2 ppm) and a leveling off of response at the higher O/sub 3/ levels. Other species usually showed significant elevations in LFP ...

Energy Technology Data Exchange (ETDEWEB)

The nuclear lamina proteins, prelamin A, lamin B, and a 70-kD lamina-associated protein, are posttranslationally modified by a metabolite derived from mevalonate. This modification can be inhibited by treatment with (3-R,S)-3-fluoromevalonate, demonstrating that it is isoprenoid in nature. We have examined the association between isoprenoid metabolism and processing of the lamin A precursor in human and hamster cells. Inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase by mevinolin (lovastatin) specifically depletes endogenous isoprenoid pools and inhibits the conversion of prelamin A to lamin A. Prelamin A processing is also blocked by mevalonate starvation of Mev-1, a CHO cell line auxotrophic for mevalonate. Moreover, inhibition of prelamin A processing by mevinolin treatment is rapidly reversed by the addition of exogenous mevalonate. Processing of prelamin A is, therefore, dependent on isoprenoid metabolism. Analysis of the conversion of prelamin A ...

Science.gov (United States)

Asynchronous Chinese hamster ovary (CHO) cells treated with conditioning hyperthermia (10 min at 45/sup 0/C) followed immediately by x irradiation with 4 Gy at room temperature display a decreased radiation response when either irradiated, or heated and irradiated again 24 h later. In addition, conditioning by 4 Gy of x radiation alone followed at 24 h by the combined heat and radiation treatment als resulted in a larger radiation D/sub 0/. Since the differential cell-cycle responses to heat- and x-ray-induced lethality are well established for CHO cells, the potential role of cell-cycle redistribution in the observed radiation desensitization was investigated by flow cytometry. At 24 h after the combined treatment, the fraction of the cells found in the G/sub 2/ + M portion of the DNA histograms was about three times that of the controls and there was a concomitant reduction in both the G/sub 1/ and S fractions. Similar observations were made after the ...

Energy Technology Data Exchange (ETDEWEB)

Individuals with male factor infertility resulting from idiopathic oligo-, astheno- or teratozoospermia are frequently offered IVF in an attempt to increase their chances of having a child. A concern remains whether these infertile males have an elevated risk of transmitting chromosomal abnormalities to their offspring. Sperm chromosomal complements from these men were assayed using the human sperm/hamster oocyte fusion system and fluorescence in situ hybridization (FISH) on sperm nuclei. For each of 5 infertile patients, 100 sperm karyotypes were analyzed and multicolour FISH analysis was performed on a minimum of 10,000 sperm nuclei for each chromosome-specific DNA probe for chromosomes 1 (pUC1.77), 12 (D12Z3), X (XC) and Y (DYZ3). As a group, the infertile patients showed increased frequencies of both numerical ({chi}{sup 2}=17.26, {proportional_to} <0.001) and total abnormalities ({chi}{sup 2}=7.78, {proportional_to} <0.01) relative to control donors when ...

International Nuclear Information System (INIS)

The rates of spontaneous interbilayer and transbilayer exchange of ["3H]dimyristoylphosphatidylcholine (["3H]DMPC) were examined in the DMPC and DMPC/dimyristoylphosphatidylethanolamine (DMPE) large unilamellar vesicles in the liquid-crystalline-, gel-, and mixed-phase states. DMPC desorption rates from either gel or liquid-crystalline phases containing DMPE are very similar to the corresponding rates from pure DMPC gel or liquid-crystalline phases. The authors proposed that the DMPC/DSPC behavior results from packing defects in gel phases composed of both DMPC and DSPC molecules because of the four-carbon difference in the acyl chain lengths of the two species. The present results strongly support this hypothesis because no such anomalous behavior is observed in DMPC/DMPE, which is similar to DMPC/DSPC in phase behavior but does not have the chain length difference. These results are not consistent with lipid headgroup dehydration as the major energetic barrier to ...

Energy Technology Data Exchange (ETDEWEB)

As silicon-integrated circuit technology enters the sub-100 nm realm, continued progress will depend on a fundamental understanding of the physics of materials processing. The high cost of processing experimental lots and the speed at which new devices must be brought to the market have created a new emphasis on realistic physical models incorporated in technology CAD (TCAD) simulation tools. The volume bring together materials scientists, TCAD researchers and silicon technologists to review recent developments in the integrated-circuit community and to identify key issues for future research in this field. Results of research on the physical mechanisms involved in silicon device processing is presented both from experimental and theoretical viewpoints. The application of this fundamental research to TCAD process simulation models is also addressed. Topics include: shallow junctions and transient enhanced diffusion; extended defects and transient enhanced ...

International Nuclear Information System (INIS)

Fluorine is known to have a beneficial role for the B diffusion reduction in preamorphized Si, and is promising for the realization of ultra-shallow junctions. Thus, we studied the F incorporation in Si during the solid phase epitaxy (SPE) process, pointing out the effects of the implanted F energy and fluence and the role played by the possible presence of dopants. The incorporation of fluorine proceeds by F segregation at the amorphous-crystalline interface, with a kinetics driven by the SPE rate. In fact, the quicker the SPE rate, the higher is the F fluence retained. Moreover, we demonstrated that F incorporated in Si layers does not appreciably affect the Is emission from spatially separated end-of-range (EOR) defects. The modification, induced by the presence of F, of the point defect density (Is and Vs) was also studied by means of B and Sb spike layers, used as local markers for Is and Vs, respectively. We showed that F is not only able ...

International Nuclear Information System (INIS)

We demonstrate that the excess vacancies induced by a 1 MeV Si implant reduce the excess interstitials generated by a 40 keV Si implant during thermal annealing when these two implants are superimposed in silicon. It is shown that this previously observed reduction is dominated by vacancy annihilation and not by gettering to deeper interstitial-type extended defects. Interstitial supersaturations were measured using B doping superlattices (DSL) grown on a silicon-on-insulator (SOI) substrate. Implanting MeV and keV Si ions into the B DSL/SOI structure eliminated the B transient enhanced diffusion normally associated with the keV implant. The buried SiO_2 layer in the SOI substrate isolates the deep interstitials-type extended defects of the MeV implant, thereby eliminating the possibility that these defects getter the interstitial excess induced by the keV Si implant. copyright 1999 American Institute of Physics.

International Nuclear Information System (INIS)

Ge pre-amorphisation step is used to reduce the high diffusivity and the transient-enhanced diffusion of boron implanted in silicon. The aim of the process is to obtain shallow P"+N junctions. The pre-amorphisation step was performed under different conditions (in ambient temperature and in nitrogen). Following the rapid thermal annealing step, end of range (EOR) defects appear at the amorphous-crystalline interface. These defects could influence the electrical characteristics of the P"+N junctions. An experimental study concerning three samples has been performed without and under a magnetic field of 800 G. The magnetic susceptibility was essentially observed in the case of the reverse current. The impact of the magnetic field, studied by varying the sample temperature, permits us to show an increase of the magnetic susceptibility when the defects present in such structures are electrically active. These results are ...

Energy Technology Data Exchange (ETDEWEB)

Vanadium doped manganese bi-oxide has been obtained from a solution containing both cations. The X-ray diffraction of this material indicates a rutile-type phase but the enlargement of some lines supports the existence of several lattice defects. Also the particle size of the doped material is significantly smaller than the one of the non-doped material obtained in the same conditions. The presence of pentavalent vanadium inside the lattice leads to a small amount of trivalent manganese. Electron microscopy shows the existence of defects which have a tendency of becoming well-ordered and to stabilize a sur-structure. At ambient temperature, the electrochemical behaviour of doped manganese bi-oxide is greatly improved when compared to the non-doped phase. This behaviour is due to the presence of numerous lattice defects and to the smaller size of crystallites. In polymer batteries, the behaviour is similar the one of the ...

International Nuclear Information System (INIS)

The rate of residual-resistivity increase and the isochronal recovery have been studied on the fcc metals Al, Ni, Cu, Pd, Ag, Pt, and Au irradiated at 4.6 K with reactor neutrons to a dose of about 10"1"9 (fast neutrons)/cm"2. The rate of resistivity increase is nonlinear as a function of irradiation-induced resistivity; computer analysis shows that the data are best fitted with an erxpression having up to third-order terms in #DELTA#rho. There are deviations from simple damage-rate theory in all cases, but an anomalous negative deviation from a linear law (convex curvature) is observed in Ni, Pd, Pt (and Fe). This behavior is most probably caused by a decrease of the specific Frenkel-defect resistivity due to defect clustering, an effect which should contribute in all metals after fast-neutron irradiation to high doses. Saturation values of resistivity and defect concentration as well as recombination volumes have veen ...

International Nuclear Information System (INIS)

Pressureless-sintered AlN and hot-pressed, pressureless-sintered and reaction-bonded SiC were neutron irradiated at temperatures between 100 and 785degC up to a fluence of 5.2 x 10"2"4 n/m"2. The hardness was increased by up to 51% in AlN and 84% in SiC. The hardness decreased after annealing at temperatures around the irradiation temperature. At the same temperatures, the macroscopic length, which was increased by irradiation, also began to decrease. The hardness and length were almost recovered after 1,200 #approx# 1,400degC annealing. Thus, hardening in irradiated AlN and SiC is controlled by the number of point defects, or, more precisely, by the strain caused by small point defect clusters which pin down dislocation movement. Dislocation loops were still observed in some samples after 1,400degC annealing while the hardness was almost recovered to that in the unirradiated state. Thus, the existence of dislocation loops is not grounds for ...

International Nuclear Information System (INIS)

The downstream failure of cable during winding, insulating, coil winding, and coil assembly is a significant issue in magnet production. The impact of these failures is costly both financially and because of the time needed to recover from them. The current approach to cabling has been to visually inspect the cable for any gross defects during cabling. To date this has been effective in finding small defects such as crossovers, which drastically reduce the mechanical integrity of the strand and thus of the cable itself. But because of the large volume of cable that will be manufactured, an automated flaw detection system that can inspect the cable and detect these types of defects will be needed. We have recently done an on-line experiment using an Eddy current system and specialized Eddy current probes to inspect cable during manufacturing. We will present the results of our inspection, demonstrating detection of ...

Energy Technology Data Exchange (ETDEWEB)

Transient enhanced diffusion of phosphorus in silicon has been investigated for implants below and above the threshold for a complete amorphization. Rapid thermal processes (electron beam) and conventional furnaces have been used for the annealing. In the case of implants below amorphization, a strong enhanced diffusion, proportional to the amount of damage produced, has been observed. The extent of the phenomenon is practically independent of the damage depth position. In contrast to this, the formation of extended defects at the original amorphous-crystalline interface makes the diffusivity strongly dependent on depth in the case of post-amorphized samples. No enhanced diffusion effect is observed if the dopant is confined in the amorphous layer, while a remarkable increase in the diffusivity is detected for the dopant located in the crystalline region beyond the amorphous-crystalline interface. Damage distribution after implantation and its evolution during ...

Energy Technology Data Exchange (ETDEWEB)

Purpose: To describe the clinical aspects and evaluate optical coherence tomography of macular microholes. Methods: Seven patients were assessed (8 eyes) with microholes of the macula. All patients underwent complete eye examination, fundus photography, fluorescent angiography and OCT-3 imaging. Results: Ages ranged from 26 to 69 years. Six patients were female (85.7%) and five of them had microhole in the right eye. The presenting symptom was decrease in visual acuity (71.3%) and central scotoma in (14.3%). Five eyes (71.4%) had no defects shown by fluorescent angiography. A defect in the outer retina was demonstrated in all eyes on optical coherence tomography. The lesions were nonprogressive. Conclusion: Macular microholes are small lamellar defects in the outer retina. The condition is nonprogressive, generally unilateral and compatible with good visual acuity. Fundus biomicroscopy associated with an optical coherence ...

Energy Technology Data Exchange (ETDEWEB)

A new atomistic approach to Si device process simulation is presented. It is based on a Monte Carlo diffusion code coupled to a binary collision program. Besides diffusion, the simulation includes recombination of vacancies and interstitials, clustering and re-emission from the clusters, and trapping of interstitials. We discuss the simulation of a typical room-temperature implant at 40 keV, 5{times}10{sup 13} cm{sup {minus}2} Si into (001)Si, followed by a high temperature (815{degree}C) anneal. The damage evolves into an excess of interstitials in the form of extended defects and with a total number close to the implanted dose. This result explains the success of the {open_quote}{open_quote}+1{close_quote}{close_quote} model, used to simulate transient diffusion of dopants after ion implantation. It is also in agreement with recent transmission electron microscopy observations of the number of interstitials stored in (311) defects. ...

Energy Technology Data Exchange (ETDEWEB)

The author investigates the diffusion and damage-annealing characteristics as a result of boron implantation through a surface oxide into the silicon, a process that is commonly realized in the fabrication of p-n junctions. Defect structures were examined using plan-view and cross-section transmission-electron microscopies. It is shown that recoil-implanted oxygen plays a critical role in determining the above annealing characteristics. For instance, transient-enhanced diffusion of boron, as is widely observed for boron-implanted silicon, does not occur in the case of through-oxide implantation. The initial suppression of the defect-enhanced diffusion lasts for a limited period of time after which enhanced diffusion occurs again. The so-called incubated enhanced diffusion' is characterized as due to recoiled-oxygen precipitation-emitting point defect that enhances boron motion. The incubation time constant, the ...

International Nuclear Information System (INIS)

A transient-enhanced diffusion has been observed during the furnace or rapid thermal annealing of As-implanted Si. The relations of the enhanced diffusion to residual defects and lattice restoration have been studied in detail. The As concentration profiles and residual defects are measured. It is found from the data that the lattice has been restored when the implanted sample is annealed at 1150 deg C (or 1050 deg C) for 1s. The defect density decreases rapidly with increase of annealing time (from 1 to 12s). The enhanced diffusion coefficient maximum appears in the annealing time ranging from 1 to 5s. Allmost a 'complete' annealing of displacemet damage is obtained and the diffusion coefficient is less than that in above-mentioned conditions when the implanted samples are annealed at 1150 deg C in the time ranging from 12 to 20s. the mechanism of lattice restoration and enhanced diffusion in annealing process have been ...

International Nuclear Information System (INIS)

In this letter, the effect of vacancies generated by preirradiated laser on dopant diffusion and activation in preamorphized silicon substrate has been studied. Laser-induced melting in silicon was used to generate excess vacancies near the maximum melt depth before silicon substrate amorphization and subsequent boron implantation. We demonstrate that by matching the preirradiated laser melt depth with the implant amorphize depth, it can effectively reduce the silicon self-interstitials released from the end-of-range defect band. The results show great suppression in boron transient enhanced diffusion and significant removal of end-of-range defects. This is attributed to the recombination of laser-generated excess vacancies with preamorphizing induced free silicon interstitials at the end-of-range region.

International Nuclear Information System (INIS)

The authors report the transient enhanced diffusion of supersaturated phosphorous in ion-implanted SPE grown Si. Precipitation proceeds rapidly to a metastable SiP phase, which can be converted to an orthorhombic form or re-dissolved by subsequent heat treatment. The effects are strongly temperature dependent, and consistent with the trapped interstitial model. The behavior of different dopants follow their relative interstitialcy diffusion coefficients. The results suggest that ion implantation induced point defects dominate over thermally activated point defects during low temperature and certain rapid thermal processing, controlling dopant deactiviation and diffusion in crystalline or amorphous silicon, and can also affect the SPE growth rate.

British Library Electronic Table of Contents (United Kingdom)

Irradiation of EP-823 (16Cr12MoWsiVNbB) ferritic-martensitic steel with 7-MeV Ni++ ions and with 30- and 70-keV He+ ions at a temperature of 500?C was followed by an increase in the microhardness, which was due to both radiation point defects and changes in the phase composition and the dislocation structure of the steel. It was found that the dependence of the largest relative increase in the microhardness on the concentration of radiation-induced point defects in the near-surface region of the steel under irradiation with different ions correlated with an analogous dependence of the surface segregation of silicon and chromium.

British Library Electronic Table of Contents (United Kingdom)

Design rules for robustness require insensitivity to local failure and the prevention of progressive collapse. This is often verified by applying the load case ''removal of a limited part of the structure''. This paper will evaluate typical structural systems for large-span timber roof structures against these requirements, comparing the results against typical reasons for damages and failures. Applying the finding that most failures of timber structures are not caused by random occurrences or local defects, but by global (repetitive) defects (e.g. from systematic mistakes), it is shown that the objective of load transfer-often mentioned as preferable-should be critically analysed for such structures. Based on these findings, proposals for structural systems and details towards a robust de...

International Nuclear Information System (INIS)

This paper is concerned with the real time automatic discriminating of flaws from two categories; i. cracks (planar defect) and ii. Non-cracks (volumetric defect such as cluster porosity and slag) using pulse-echo ultrasound. The raw ultrasonic flaws signal were collected from a computerized robotic plane scanning system over the whole of each reflector as the primary source of data. The signal is then filtered and the analysis in both time and frequency domain were executed to obtain the selected feature. The real time feature analysis techniques measured the number of peaks, maximum index, pulse duration, rise time and fall time. The obtained features could be used to distinguish between quantitatively classified flaws by using various tools in artificial intelligence such as neural networks. The proposed algorithm and complete system were implemented in a computer software developed using Microsoft Visual BASIC 6.0 (author)

International Nuclear Information System (INIS)

The authors have shown that toxicity of paraquat for Escherichia coli is increased over 1-fold in strains defective in the biosynthesis of spermidine compared to isogenic strains containing spermidine. The increased sensitivity of these spermidine-deficient mutants to paraquat is eliminated by growth in medium containing spermidine or by endogenous supplementation of spermidine by the use of a speE"+D"+ plasmid. No paraquat toxicity is seen in the absence of oxygen, even in amine-deficient strains, indicating that superoxide is the agent responsible for the increased toxicity. However, the specific mechanisms responsible for the increased paraquat toxicity in the spermidine-deficient mutants remain to be determined. The marked sensitivity to paraquat of E. coli deficient in spermidine is of particular interest, since such mutants have no other phenotypic properties that can be easily assayed. This increased sensitivity has been used as the basis of a convenient ...

British Library Electronic Table of Contents (United Kingdom)

Eddy current testing is one of the most widely used methods in non-destructive testing for the inspection of conductive materials. Numerical modelling of eddy current testing has emerged as an important approach alongside experimental studies. This paper investigates an application of numerical modelling and experimental study as a means of the quantitative non-destructive evaluation (QNDE) of defects in conductive samples. There are two methods of measuring eddy current response, more commonly by measuring the change in impedance of the eddy current probe coil, or as used in this work, by measuring the change in magnetic field directly using magnetic field sensors such as superconducting quantum interference devices, giant magneto resistance, or as in this case Hall sensors. Specifically,...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to evaluate the role of the strain-relaxation processes on the leakage current of embedded SiGe S/D junctions. Current-voltage (I-V) and capacitance-voltage (C-V) characteristics were measured to further investigate the relaxation degree of embedded SiGe S/D junctions in the regime where partial relaxation by misfits dislocations is assumed, yielding a reduction of the leakage current density. Further, the impact of the ion implantation-related defects on the electrical performance is discussed. The analysis is complemented with structural characterization based on High Resolution Transmission Electron Microscopy (HRTEM) and Nomarski microscopy. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Science.gov (United States)

We developed mice with germline endogenous expression of oncogenic Hras to study effects on development and mechanisms of tumor initiation. They had high perinatal mortality, abnormal cranial dimensions, defective dental ameloblasts, and nasal septal deviation, consistent with some of the features of human Costello syndrome. These mice developed papillomas and angiosarcomas, which were associated with Hras(G12V) allelic imbalance and augmented Hras signaling. Endogenous expression of Hras(G12V) was also associated with a higher mutation rate in vivo. Tumor initiation by Hras(G12V) likely requires augmentation of signal output, which in papillomas and angiosarcomas is achieved via increased Hras-gene copy number, which may be favored by a higher mutation frequency in cells expressing the oncoprotein. PMID:19416908

International Nuclear Information System (INIS)

By method of transmission electron microscopy and measuring of microhardness the peculiarities of influence of radiation defect clusters on molybdenum radiation hardening along range path of protons with 30 MeV initial energy are studied. Decrease effect of hardening growth value and even its absence depending on irradiation dose in the range of 10-20 MeV proton energies in presence of high density of radiation defect dispersed clusters is revealed. It is shown experimentally that this effect is connected with accumulation of hydrogen up to not very high concentrations (not more than 5x10"-"4 at.%) at the expense of elastic and inelastic proton scattering. 5 refs.; 5 figs.

Energy Technology Data Exchange (ETDEWEB)

We have investigated the diffusion of Sb in Si in the presence of defects injected by high-energy implantation of Si ions at room temperature. MeV ion implantation increases the concentrations of vacancies, which induce transient-enhanced diffusion of Sb deposited in Si. We observed a significant enhancement of Sb diffusion. Secondary ions mass spectroscopy has been performed on the implanted samples before and after annealing. Rutherford-backscattering spectrometry has been used to characterize the high-energy implantation damage. By fitting diffusion profiles to a linear diffusive model, information about atomic scale diffusion of Sb, i.e. the generation rate of mobile state Sb and its mean migration length were extracted.

International Nuclear Information System (INIS)

The surface permeability of concrete walls and floors in houses was measured with a specially designed permeameter, based on measuring the air-flow induced by a pressure difference across a temporary test seal applied to a surface. The permeability of bulk concrete is 10"-"1"6 m"2. Areas free of surface defects had permeability ranging from 10"-"1"4 to 10-"1"6 m"2. However, surface defects are common on concrete wall surfaces, which increase the permeability to >10"-"1"2 m"2. This is too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Satisfactory seals require either extended contact width or mechanical removal of the surface layer. (orig.). (2 figs., 1 tab.).

British Library Electronic Table of Contents (United Kingdom)

A series of desilicated ZSM-5 catalysts previously shown to have improved catalytic performance in the MTG (methanol-to-gasoline) reaction [M. Bjorgen, F. Joensen, M.S. Holm, U. Olsbye, K.-P. Lillerud, S. Svelle, Appl. Catal. A 345 (2008) 43] was subjected to thorough examination using FTIR. Clearly, defects represented by internal Si-OH sites are removed upon NaOH treatment. In a parallel manner, free Si-OH sites increase in concentration and the results point to a selective mechanism for formation of mesopores as the framework dissolution preferentially takes place at defective sites in the crystallites. The acid properties of the desilicated materials were investigated by applying CO and collidine (2,4,6-trimethylpyridine) as molecular probes. Monitoring the induced frequency shifts upo...

International Nuclear Information System (INIS)

Eddy current testing (ECT) method is widely used as the non-destructive evaluation (NDE) of the various kinds of material degradation occurring in nuclear power plants (NPPs) components including steam generator (SG) tubes. Detection of any defects or flaws in the steam generator tubes in the early stage is very important in maintenance of NPP for its primary role as the pressure boundary with thin wall thickness. Although the ECT technique provides lots of information for a SG management, it has a generic problem in its reliability due to a low ability in detect of small defects and some difficulty in a signal analysis. For the improvement of these shortcomings in conventional ECT, profile-MRPC (motorized rotating pancake coil) ECT technology was developed in KAERI. The key of this new technology is the development of new eddy current probes, designated as a diagnostic probe (D-probe). The D-probe is furnished with a simultaneous dual function ...

International Nuclear Information System (INIS)

First results on the effects of strain on transient enhanced diffusion and deactivation of As-implanted ultrashallow junctions are presented. A significant effect of strain on the magnitude and timescale of transient enhanced diffusion is observed, which is consistent with the stabilization of interstitial-type defects by tensile strain. Our results show no significant impact of strain on As electrical activity during the deactivation timescale accessed in this study.

Energy Technology Data Exchange (ETDEWEB)

The risk perception of the public consists of two components: the objectively factual component and the subjectively irrational component. The two strategies adopted by the German gas supply industry are the internal and the external communication strategy. Concepts and measures of accident precaution, registration and analysis of accident data (installation and operating errors, defects on flue systems, pipelines and valves, subsequent installation of gas appliances) are discussed. (R.P.)

UK PubMed Central (United Kingdom)

Nucleotide pool sanitizing enzymes Dut (dUTPase), RdgB (dITPase), and MutT (8-oxo-dGTPase) of Escherichia coli hydrolyze noncanonical DNA precursors to prevent incorporation of base...Full Text Available

International Nuclear Information System (INIS)

One normally identifies the prediction of tachyons with a higher spin problem. We show that the same phenomenon also happens with certain spin-1/2 equations, in exactly the same circumstances. Furthermore, we prove that these equations also have the defect of possessing solutions with complex energies, even with the smallest external fields. The consequences of these results are analyzed.

UK PubMed Central (United Kingdom)

The luminescent characteristics of Ru(bpy)₂dppz²⁺ (dppz = dipyrido[3,2-a:2′,3′-c]phenazine), a DNA light switch, were...Full Text Available

UK PubMed Central (United Kingdom)

An assay method is described for measurement of absolute concentrations of the molybdenum cofactor, based on complementation of the defective nitrate reductase ('apo nitrate reductase') in extracts...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Positron emission tomography (PET) and magnetic resonance imaging (MRI) studies were performed on a case of neuro-Behcet's syndrome. In accordance with the clinical signs, FDG PET (using /sup 18/F-labeled 2-F-2'-desoxyglucose) revealed disseminated storage defects in the cerebrum and cerebellum. Focal regions of enhanced signal intensity were demonstrated in the parietal white matter of the cerebrum in T2-weighted images and in the brain stem by MRI. (orig.).

International Nuclear Information System (INIS)

Transient enhanced diffusion in boron-implanted silicon is interpreted as being due to the fact that during rapid thermal annealing a relaxation process takes place, associated with quasi-chemical reactions including defects. A simple analytical model makes it possible to describe the annealing mechanism on a microscopic scale in terms of reaction-diffusion processes. The measured dependences of the boron diffusion coefficient of the enhanced diffusion on time, temperature and implantation energy are satisfactorily explained. (author).

Energy Technology Data Exchange (ETDEWEB)

Some of the results of property measurements of CeO{sub 2} and its solid solutions were reviewed. The deviation from stoichiometry of undoped and doped CeO{sub 2} was presented in several figures, which suggested that CeO{sub 2} fired at high temperatures in air might be nonstoichiometric in some degree. At low temperatures, the deviation from stoichiometry in doped CeO{sub 2} is higher than undoped CeO{sub 2}. As another interesting property, CeO{sub 2} shows high solubility to trivalent cations such as rare earth elements. A possible reason behind this high solubility was presented. The nonstoichiometric defect in undoped CeO{sub 2} and the trivalent cation in solid solution with CeO{sub 2} have to be compensated by other defects. The possible defect structures in this solid solution were reviewed and the most probable structure was chosen based on density measurement and impurity dependence of oxygen diffusion ...

International Nuclear Information System (INIS)

The phenomenological description of the giant magnetoresistance effect as well as discussion of the requirements which must be fulfilled in giant magnetoresistance thin film structures are given in the first part of our review. In the second part the magnetization reversal and giant magnetoresistance effect of antiferromagnetically coupled multilayers, spin Valve and pseudo-spin valve thin film structures are explained. For these structures we also discuss the influence of the structure defects such as surface roughness and pinholes on the giant magnetoresistance effect. (author)

Energy Technology Data Exchange (ETDEWEB)

The precipitation of excess silicon interstitials into dislocation loops is modeled. This situation occurs when an amorphous layer is created at the surface in order to avoid boron channeling and form shallow p junctions. The modeling of the nucleation of these extended defects is included into the process simulator IMPACT-4. Their density and mean radius are calculated for several annealing times and temperatures and they are compared with experimental characterizations. This is the first step towards a full modeling of the complex processes involved in the transient enhanced diffusion of boron.

Science.gov (United States)

In this work, energy-based features for gear fault diagnosis and prediction are proposed. The instantaneous energy density is shown to obtain high values when defected teeth are engaged. Three methods are compared in terms of sensitivity, reliability and computation effectiveness. The Wigner Ville distribution is contrasted to the wavelet transform and the newly proposed empirical mode decomposition scheme. It is shown that all three methods are capable of a reliable prediction. An empirical law, which relates the energy content to the crack magnitude is established.

International Nuclear Information System (INIS)

In this article carbon co-implantation and step-by-step thermal treatments of shallow p"+-n-junctions formation were used with the purpose of extended defect suppression and reduction of boron transient enhanced diffusion. A substantial improvement of the structural and electrical parameters of shallow p"+-n-junctions has been achieved by using the additional carbon implantation and step-by-step thermal treatments. (authors)

UK PubMed Central (United Kingdom)

Dendritic cells (DC) are the most potent antigen-presenting cells and play a central role in the induction of antiviral immune responses. Recently, we have shown that monocyte-derived DC (MoDC) from...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A case study is presented about the failure of a stainless steel blade reinforcing band in a steam turbine. The inspection results and analysis of samples of material are discussed. Being pitting corrosion and cracks the main defects found, a study of chemical composition and heat treatment state of the steel is made and findings are related to type of failure. (orig.)

UK PubMed Central (United Kingdom)

Bony craniofacial deficits resulting from injury, disease, or birth defects remain a considerable clinical challenge. In this study, microsphere-based scaffold fabrication methods were use to...Full Text Available