bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of Klebsiella pneumoniae and Acinetobacter radioresistens from Dish Wash Scrubbers
Authors: Murali Reshma , James Ligimol , Beena A. K. , Sudhakaran V. Aparna
Published: August 2022

Aims: To identify predominant microorganisms in dish washing scrubbers collected from ten different sources.

Study Design: Collection of dish wash scrubbers from different sources, pour plating of appropriately prepared dish wash scrub suspensions and subsequent isolation and identification of predominant isolates. Assessment of antibiotic susceptibility of the selected isolates by disc diffusion assay.

Place and Duration of Study: April, 2018 - June 2018.

Methodology: A total of 10 dish wash scrubbers (synthetic green scrubber pads free from any anti-bacterial preservatives belonging to the same brand) were collected from various sources. Appropriately prepared dish wash scrub suspensions in peptone water were pour plated on Plate Count Agar (PCA) and MacConkey agar. Predominant colonies selected from the plates based on the colony morphology were subjected to Grams staining, catalase, oxidase, indole, citrate, urease tests and genotypic identification by 16S ribosomal RNA sequencing. The identified isolates were tested for their susceptibility to eight antibiotics by disc diffusion method.

Results: Irrespective of the sample source, most of the dish wash scrubbers sampled harbored similar types of colonies. From the colonies obtained two of them were identified by 16S rRNA sequencing and subsequent blasting as Klebsiella pneumoniae and Acinetobacter radioresistens. The isolates were deposited in the NCBI database with accession numbers MK032217 (Klebsiella pneumoniae RSV02) and MK032134 (Acinetobacter radioresistens RSV 01). These isolates were tested for their susceptibility to different antibiotics and Acinetobacter radioresistens RSV 01 was found to be more antibiotic susceptible than Klebsiella pneumoniae RSV02.

Conclusion: Observations of this study confirm the potential role of dish wash scrubbers as vehicle for potential pathogens and their ability to act as cross contaminating agents in food processing environments.
Influence of Nitrogen and Sulphur Levels on Growth and Yield of Lentil (Lens culinaris M.)
Authors: Bindu Yadla Mereena Madhu , Umesha C. , Subha Kakulavarapu Navya Sri , Sindhu Veluri Sree
Published: August 2022

The field experiment entitled ‘‘Influence of Nitrogen and Sulphur levels on growth and yield of Lentil (Lens culinaris M.)’’ conducted during Rabi 2021 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P). The soil of experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 7.2), low in organic carbon (0.22 %), available N (171.48 kg/ha), available P (12.3 kg/ha) and available K (235.7 kg/ha). The experiment was laid out in Randomized Block Design with nine treatments which are replicated thrice. The treatments viz; 1: N-10 kg/ha + S-10 kg/ha, 2: N-10 kg/ha + S-20kg/ha, 3: N-10 kg/ha + S-30 kg/ha , 4: N-20 kg/ha + S-10 kg/ha , 5: N-20 kg/ha+ S-20 kg/ha , 6: N-20 kg/ha + S-30 kg/ha , 7: N-30 kg/ha + S-10 kg/ha , 8: N-30 kg/ha + S- 20 kg/ha ,9: N-30 kg/ha + S-30 kg/ha. Treatments consisted of three levels of Nitrogen (10, 20, 30 kg ha-1) and four levels of Sulphur (10, 20 and 30 kg ha-1). The results obtained that application of Nitrogen 30kg/ha along with Sulphur 30kg/ha recorded significantly higher Plant height (42.68cm), Number of nodules/plant (7.33) Plant dry weight (19.30g/plant), Number of Pods/plant (159.42), Number of Seeds/pod (1.80), Seed yield (1719.3kg/ha) and Stover yield (2814 kg\ha) and Harvest Index (37.92%). Higher Gross returns (87684.30 INR/ha), Net return (59773.60 INR/ha) and Benefit cost ratio (2.14) were obtained in the treatment with application of Nitrogen 30kg/ha along with Sulphur 30kg/ha. Sulphur application up to 30 kg ha-1 increased significantly the uptake of N and K by the crop. Protein content in grain increased significantly with the addition of N (30 kg ha-1) and sulphur (30 kg ha-1). Yield of lentil increased linearly with increasing levels of Sulphur. Therefore, it is concluded that the application of Nitrogen 30kg/ha + Sulphur 30kg/ha was more productive and economically feasible.
Effect of Gibberellic Acid and Naphthalene Acetic Acid on Growth, Yield and Quality of Chilli (Capsicum annum L.)
Authors: Panda Satyasuravit Devchandan , Deepanshu . , Fatmi Urfi
Published: August 2022

The experiment entitled "Effect of gibberellic acid and naphthalene acetic acid on growth yield and quality of chilli (Capsicum annum L.)” was conducted at Department of Horticulture, Naini Agricultural Institute, SHUATS, Prayagraj during August to December, 2021. Experiment was laid out in Factorial Randomized Block Design with three replications and ten treatment combinations. The experiment consisted of two factors. Factor A: Variety (two variety) as TMPH-449, TMPH-443 and Factor B: Plant growth regulator T1: NAA (30ppm) T2: NAA (40ppm) T3: GA3 (50ppm) T4: GA3 (100ppm). The results revealed that among the varieties studied, variety TMPH-449 resulted better in vegetative growth (Plant height, leaf area) whereas variety TMPH-443 resulted better in vegetative growth (Number of branches per plant), yield parameter (Minimum days taken for 50 percent flowering, minimum days to first harvest, length of fruit, fruit girth, weight of fruit, number of chilli fruit per plant, average fruit yield per plant, fruit yield per hectare), and quality parameter (total soluble solids). Among different concentrations of growth regulator application T2: NAA (40ppm) gave better result in vegetative growth (Plant height, Number of branches per plan, leaf area), yield parameter (Minimum days taken for 50 percent flowering, minimum days to first harvest, length of fruit, fruit girth, weight of fruit, number of chilli fruit per plant, average fruit yield per plant, fruit yield per hectare), and quality parameter (total soluble solids). The best interaction amount different variety and growth regulators were found to be variety TMPH-443 and Growth regulator T2: NAA (40ppm) which give maximum growth and quality characteristics of chilli.
Herbicide Efficacy as Influenced by Spray Fluid Quality and Adjuvants on Yield and Economics of Maize (Zea mays L.)
Authors: Bhavitha K. , Suresh K. , Madhavi M. , Prakash T. Ram
Published: August 2022

A field investigation was conducted during Rabi season of 2020-21 at Professor Jayashankar Telangana State Agricultural University, Rajendranagar, Hyderabad to assess the herbicide efficacy as influenced by spray fluid quality and adjuvants on yield and economics of maize (Zea mays L.). The results revealed that there was a positive influence on addition of ammonium sulphate as adjuvant when saline waters (C3S1 and C3S2 classes) were used as spray fluid as compared to application of herbicides with saline waters alone. Tank mix application of halosulfuron methyl at 67.5 g ha-1 + atrazine at 0.5 kg ha-1 with 2% ammonium sulphate with C3S1 class water as spray fluid recorded higher yield (5.00 and 8.15 tons ha-1) and economics of maize with reference to other saline water treatment combinations and proved as effective treatment following to halosulfuron methyl at 67.5 g ha-1 + atrazine at 0.5 kg ha-1 with 2% ammonium sulphate with distilled water as spray fluid.
Effect of Different Treatments and Packaging Material on Germination and Seed Quality Characteristics of Foxtail Millet (Setaria italica) under Ambient Storage Condition (Variety-SiA-3088)
Authors: Sirinandini Dadireddy , Dayal Abhinav , Rai Prashant Kumar
Published: August 2022

The current study was conducted in 2021 at the Lab Experimentation Center at the Genetics and Plant Breeding Department of the Naini Agricultural Institute at the Sam Higginbottom University of Agriculture, Technology, and Sciences in Prayagraj. Four replications and thirteen different treatments, including T0- control, T1: Cow urine at 2% for 6 hours; T2: Cow urine at 4% for 12 hours; T3: Cow urine at 8% for 24 hours. T4: 0.25 percent seaweed extract for 12 hours; T5: 0.50 percent seaweed extract for 12 hours; T6: 0.75 percent seaweed extract for 12 hours. T7- Tulasi leaf extract at 5% for six hours, T9: Tulasi leaf extract 15% for 24 hours, T8: Tulasi leaf extract 10% for 12 hours T10 has a 2 percent moringa leaf extract, T11 a 4 percent moringa leaf extract, and T12 an 8 percent moringa leaf extract. and three different types of packaging P1: polythene bag, P2: gunny bag, and P3: hermetic container taken for the second and fourth months of 2020–21, respectively. Analysis of variance data from the lab experiment was laid out in completely randomized block design showed that the foxtail millets seeds variety produced superior results for all of the characters under study, including germination percentage, shoot length, root length, seedling length, seedling fresh weight, seedling dry weight, and seed vigour index -1 and -2. Among the three packaging materials, the variety Sia-3088 treated with cow urine (T1-cow urine 2%) was found to be beneficial in all seedling features. Seeds were shown to be effectively stored in polythene bags with high percentage of germination under ambient storage conditions.
Studies on Use of NPK and Organic Manures on Growth, Yield and Quality of Lettuce (Lactuca sativa) cv. Grand Rapid
Authors: Chanjaya A. T. , Prasad Vipin M. , Topno Samir E. , Bahadur Vijay
Published: August 2022

The experiment was conducted in the Departmental field of Horticulture, Naini Agricultural Institute, Sam Higginbottom, University of Agriculture, Technology and Sciences, Prayagraj (U.P) during 2020-2021, by randomized block design consisting of 7 treatments and three replications with different combination of NPK and Organic manures. Based on the present investigation, it is concluded that the treatment T5 (50% RDF + 25% FYM + 25% Poultry manure) was found to be superior all-over other treatments with respect to Plant height at 45 DAS (21 CM), Number of leaves plant-1 at 45 DAS (21.1), Leaf length at 45 DAS (19.90 cm), Leaf width at 45 DAS (16.2 cm), Leaf area at 45 DAS (232.5 cm), Leaf area index at 45 DAS (20.4 cm2), Leaf weight (107.6 g), Leaf yield plot-1 (10.5 kg), Leaf yield ha-1 (23.4 kg), Vitamin-C (3.5) content and TSS (3.4°Brix) of Lettuce under agro-climatic condition of Prayagraj. Among all other treatments, T5 (50% RDF+ 25% FYM + 25% Poultry manure) has obtained Highest Gross return, Net return, and Benefit Cost ratio (1:3.8) which states that it is economically profitable compared to all other treatments.
Gut Endosymbiont Disruption through Antibiotics Influences the Metabolic Homeostasis in Spodoptera frugiperda (Lepidoptera: Noctuidae) Larvae
Authors: Winssy T. Deborah , Gopal N. O. , Anandham R. , Balasubramani V. , Jeyarani S.
Published: August 2022

Fall armyworm as a polyphagous voracious feeder reported causing yield losses in most agriculturally important crops. As this insect had developed resistance against most of the insecticides, there is a need for an alternate approach to management. Gut endosymbiotic bacteria play a significant role in host feeding, digestion, and defense response throughout the life stages of insects. In the present study, we have isolated and identified the gut endosymbiotic bacteria of fall armyworm and the larvae were treated with antibiotics. The results showed that the maximum bacterial population was observed in the fourth instar of field-caught larvae and the least population was observed in the fourth instar artificially reared population. Based on the biochemical results the isolated gut endosymbiotic bacteria mainly comprised of Bacillus sp, Enterococcus sp., and Enterobacter sp. Based on the susceptibility of gut bacteria to different antibiotics, 6 antibiotic treatments with one insecticide treatment were administered to an artificial diet reared with third instar larvae and their dietary indices were evaluated. Among the antibiotic treatment, there was a reduction in the dietary indices in the larvae treated with Ciprofloxacin CIP5 (45.33%) and Cefotaxime CTX30 (41.73%) and an increase in dietary indices in the larvae treated with Nalidixin NA30 (31.58%), Doxycycline DO30 (8.82%), Vancomycin VA30 (22.05). Elimination of gut bacteria with a suitable antibiotic will affect the insect’s feeding and dietary indices subsequently decreasing the relative growth rate and insect’s physiology. Hence, gut bacteria-based green control measures might be used as an alternative approach for insecticides for the effective management of fall armyworm.
Effect of Panchagavya on Growth, Yield and Quality of Tomato (Lycopersicon esculentum L.)
Authors: Prathima Kunamalla , Deepanshu . , Singh Devi
Published: August 2022

An experiment was conducted to determine the “Effect of Panchagavya on growth, yield and quality of tomato (Lycopersicon esculentum L.)” at Horticulture Research Field, Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology And Sciences, Prayagraj (Uttar Pradesh) during Kharif season 2021. Total 12 treatments and 3 Hybrids were replicated thrice in a factorial randomized block design (FRBD). Hybrids are TMTH-234, TMTH-2267 and TMTH-288. These hybrids were treated with different concentrations of Panchagavya (1%, 2%, 3%) and control (water spray) were sprayed at 15, 30, 45 days after transplanting. The application of Panchagavya significantly affects the vegetative as well as reproductive attributes of the crop. The results showed that hybrid TMTH-2267 with 3% spray of Panchagavya performed best in terms of plant height (78.14 cm), days to 50% flowering (71.10), days to first harvest (98.10), polar diameter (5.47 cm), radial diameter (6.90 cm), number of fruits per plant (24), fruit weight (280.08 g), fruit yield per plant (1.68 kg), yield per hectare (55.88 t) and TSS (5.83 0Brix).
Cryptocurrency and Global Practices: Lessons for Nigeria
Authors: Ogunode O. A. , Iwala A. T. , Awoniyi O. A. , Amusa B. O. , Omosebi T. R. , Kassim S. K. , Akintoye R. I.
Published: August 2022

This paper examined cryptocurrency and its global practices with particular reference to salient lessons for the Nigerian economy. The desk review methodology anchored on content analysis was used for the study. The paper identified distrust in political systems, weak domestic currency and high inflation rates as key factors fueling the growth of cryptocurrency usage in Nigeria thus motivating individuals to resort to cryptocurrencies as a tool for wealth preservation and inflation hedge. The study also found that the existence of trust deficit and challenges associated with privacy concerns, system uptime and stringent onboarding requirements were capable of derailing the success of the newly launched digital currency(‘e-naira’) issued by government to curtail cryptocurrency usage in Nigeria. The study concluded that cryptocurrencies and central bank issued digital currencies (CBDCs) are now part and parcel of the new economic order and represents the future of finance. It therefore recommended that nation states should work assiduously to develop uniformly agreed regulatory framework and global standards for the usage of cryptocurrencies.
An ultrafast time‐resolved anisotropy study of bacteriochlorophyll a in pyridine
Authors: Martinsson Peter , Sundström Villy , Åkesson Eva
Published: July 2002

The transient absorption anisotropy spectrum of bacteriochlorophyll a (BChl a) in pyridine was measured in the wavelength interval 550–850 nm, 1 ps after optical excitation with a 792‐nm femtosecond light pulse. In the wavelength region of Q
y absorption and stimulated emission (775–825 nm), the anisotropy was found to be close to the theoretically expected value (0.4) for a two‐level system. In the wavelength region 650–750 nm, where the transient absorption signal is dominated by excited state absorption, the anisotropy is reduced to ∼0.18. Anisotropy kinetics were measured at several wavelengths and found to be constant within the time window 0–5 ps, showing that no internal dynamics of the BChl a molecule change the anisotropy on the time scale of tens of picoseconds.
Macro Approach and Fuzzy Modeling of Entrapped Biocatalyst
Authors: Ruggeri Bernardo , Sassi Guido , Bosco Francesca
Published: July 2002

The interactions between a strain of Saccharomyces cerevisiae and an alginate matrix are investigated to ascertain the main factors affecting the bioreaction evolution. During the tests several parameters (glucose, ethanol, calcium ion and biomass concentration, pH, and alginate bed diameter) were evaluated, coupled with microscopic investigation inside the beads to determine the spatial biomass distribution. A detailed analysis of macro parameters and a correlation among them are proposed using a fuzzy algorithm. A global two‐step fuzzy model results in which biomass distribution inside the beads is represented as a hidden parameter.
Direct Involvement of Luteinizing Hormone in Uterine Function
Authors: Shemesh M , Mizrachi D , Gurevich M , Stram Y , Shore LS , Fields MJ
Published: July 2002

Contents

The effect of bovine LH on bovine uterine tissue from three phases of the oestrous cycle was studied. It was found that in the luteal phase the endometrium, myometrium and cervix contain a LH receptor (LH‐R) mRNA transcript and the 93 kDa receptor protein. Both LH‐R protein and its mRNA were also found in the uterine vein but mainly at pre‐oestus/oestrus. Incubation of cervical minces from the luteal phase with LH significantly increased (p < 0.05) the intracellular cAMP, inositol phosphate and cyclooxygenase as well as the production of PGE2 but not PGF2α. Induction of endometrial cyclooxygenase by LH is associated with release of PGF2α in the late luteal phase and 2 to 4 days postovulation. In contrast, in the pre‐oestrous/oestrous uterine vein, the signal for the transcript for LH‐R and the LH‐R protein was significantly higher than at other stages of the cycle. Incubation of uterine vein minces from pre‐oestrus/oestrus with LH significantly increased intracellular concentration of cyclooxygenase as well as production of both PGE2 and PGF2α. The presence of physiologically active LH‐R in the uterine tissue suggests a direct involvement of LH in uterine function, i.e. uterine relaxation by cAMP and PGE2 and regression of the corpus luteum by uterine PGF2α.
Transient phosphorus diffusion from silicon and argon implantation damage
Authors: Giles Martin D.
Published: July 2002

We have investigated transient enhanced diffusion of phosphorus in silicon following implantation with silicon or argon ions at low doses. Both conditions show uphill diffusion of phosphorus due to the defect gradients, but the resulting profiles are quite different because of differences in the initial defect distributions. These experiments support an interstitial pair diffusion mechanism for phosphorus and show the importance of bulk recombination in determining defect distributions for argon damage annealing.
Etch mechanism in the low refractive index silicon nitride plasma-enhanced chemical vapor deposition process
Authors: Kuo Yue
Published: July 2002

In this letter the author reports a generalized mechanism for the plasma-enhanced chemical vapor deposition silicon nitride process which includes simultaneous surface deposition and etching reactions. The etching mechanism is caused by the hydrogen plasma in combination with the high plasma potential. For each deposition versus power or refractive index versus power curve there is a critical point which is determined by the critical power Wcritical. When the power is lower than Wcritical, the process can be explained by conventional deposition mechanisms. When the power is higher than Wcritical, the hydrogen etching mechanisms becomes important. Wcritical depends on other process parameters such as the composition of the feeding stream. Experimental results confirmed the hydrogen etching mechanism, which is selective.
Properties of Al2O3 optical coatings on GaAs produced by oxidation of epitaxial AlAs/GaAs films
Authors: Schubert E. F. , Passlack M. , Hong M. , Mannerts J. , Opila R. L. , Pfeiffer L. N. , West K. W. , Bethea C. G. , Zydzik G. J.
Published: July 2002

Auger analysis of oxidized AlAs epitaxial layers grown by molecular-beam epitaxy reveals that the composition of the films is stoichiometric Al2O3. High optical quality of the films is demonstrated by optical reflection and transmission measurements. A reflectivity of 6% is measured for an antireflection coating on GaAs. Leakage currents in the nA range and resistivities ≳5×1011 Ω cm are deduced from current-voltage measurements. Capacitance-voltage measurements on metal-oxide-semiconductor structures using the Al2O3 films obtained by oxidizing AlAs, reveal a significant reduction of the interface state density as compared to conventional, electron beam evaporated Al2O3.
Sublimation mechanisms of (100) and (111) CdTe
Authors: Tatarenko S. , Daudin B. , Brun D.
Published: July 2002

The sublimation activation energies of (100) and (111)B CdTe have been determined by reflection high energy electron diffraction oscillation measurements. An interpretation of the data is proposed, assuming that the sublimation can be described in both cases by a two-step mechanism. In the explored temperature range, the sublimation kinetics are governed by a common process, leading to a unique activation energy value of 1.90±0.05 eV.
Influence of hydrogen and oxygen plasma treatments on grain-boundary defects in polycrystalline silicon
Authors: Nickel N. H. , Yin A. , Fonash S. J.
Published: July 2002

The effects of hydrogen, oxygen, and helium plasma exposures on the grain-boundary defects of polycrystalline silicon (poly-Si) were examined. While a remote hydrogen plasma passivates Si dangling-bonds efficiently no change in the defect density is observed after exposing poly-Si to a remote oxygen plasma. On the other hand, an electron cyclotron resonance oxygen and helium plasma results in a decrease of the spin density. Secondary ion mass spectrometry measurements reveal that both plasma exposures vastly increase the hydrogen content of the samples while the O concentration remains unchanged. The increase of the H concentration is proportional to the number of passivated grain-boundary defects.
Fullerene doped glasses
Authors: Lin Fucheng , Mao Sen , Meng Zhicong , Zeng Heping , Qiu Jianqing , Yue Yong , Guo Ting
Published: July 2002

Optical glasses doped with a fullerene mixture of C60/C70 were made in our lab. Three peaks, corresponding to C60, C70, and a modified fullerene (possibly its oxide), respectively, were found in the chromatogram of high performance liquid chromatography (HPLC) analysis of the 0.1-wt % fullerene doped phosphate glass. Depending on the doping procedure and impurity, weak to strong interacting between C60 and its environment was found by the nuclear magnetic resonance study. For both phosphate and fluorophosphate glasses with 0.01-wt % fullerene mixture doping, the eigen UV absorption edge showed a significant blueshift, indicating that the bonding between the nonbridging oxygen in these glasses was subjected to a strong change due to the fullerene doping.
Dummy load technique for power efficiency estimation in rf discharges
Authors: Savas S. E. , Horne D. E. , Sadowski R. W.
Published: July 2002

We have developed a simulated load technique for estimating power dissipation and effective impedance of the discharge which is useful over a wide range of driver frequencies. This is used to calculate the power delivered to the plasma and plasma current for frequencies from 0.12 to 13.56 MHz. This technique allows an efficiency calibration curve to be made for a given match circuit which can be quickly applied to any new discharge condition to give match efficiency.
NMR in a diamond anvil cell
Authors: Lee Sam-Hyeon , Luszczynski K. , Norberg R. E. , Conradi Mark S.
Published: July 2002

Techniques are presented for NMR measurements at high pressure in a diamond anvil cell. Two schemes of coupling radio frequency magnetic fields to the spins inside a metal gasket are described. As a demonstration of the techniques, the relaxation times T1 and T2 of methanol:ethanol solution have been measured to 52 kbar at room temperature.
Temperature-controlled vacuum chamber for x-ray diffraction studies
Authors: Mudd Courtney P. , Tipton Harold , Parsegian Adrian V. , Rau Don
Published: July 2002

In order to apply the osmotic stress method for direct measurement of forces between membranes or between macromolecules, we have designed and built an x-ray camera which can control the sample temperature from 0 °C to 70 °C while confining the path of diffracted x rays to an evacuated space between the sample and film. The system uses a linear feedback sensor which provides ±0.1 °C accuracy and a base-line stability of 0.02 °C over the entire operating range. The controller uses solid-state thermoelectric modules to regulate the temperature of the sample and is capable of automatically shifting from the heating to cooling mode of operation to regulate at temperatures near room temperature. The sample solutions are mounted between two Mylar windows in a removable cell which can be cleaned and loaded outside the instrument. The film plate is mounted on a slide which can be positioned between 4 and 22 in. from the sample. A beam stop is also mounted on the film plate holder and can be adjusted 1 in. both vertically and laterally. The x-ray entry port also has lateral and vertical adjustments for easy alignment with the collimator. The sample cell and film plate mechanism are located within an aluminum and polycarbonate chamber for operation at pressures as low as 0.001 atm.
Compact He-atom detector for high-resolution surface phonon measurements
Authors: Martini K. M. , Franzen W. , El-Batanouny M.
Published: July 2002

A new compact detector for measuring the velocity distribution of He atoms scattered from an oriented single-crystal surface by the time-of-flight (TOF) method is described. In this system the scattered atoms are tagged by exciting them to the 23S metastable state by cross bombardment with a pulsed electron beam. After traversal of a given flight path (80.9 mm), the metastables are detected by a multichannel-plate electron multiplier, and their TOF distribution is recorded. The incident supersonic He beam is generated by a nozzle source, resulting in a very narrow energy distribution of the incident beam. The angular and energy resolutions of the detector are analyzed and its advantages and limitations are described. Finally, a demonstration of the performance of the instrument in inelastic scattering from a Cu(100) surface is presented.
Design and implementation of a low temperature near-field scanning optical microscope
Authors: Grober Robert D. , Harris Timothy D. , Trautman Jay K. , Betzig Eric
Published: July 2002

The design and implementation of a low temperature (T≥1.5 K), near-field scanning optical microscope are described herein. This microscope, which is based on the recently developed tapered fiber probe, is optimized for luminescence imaging and spectroscopy of mesoscopic semiconductor systems.
Multiple energy computed tomography (MECT) at the NSLS: Status report
Authors: Wu X. Y. , Dilmanian F. A. , Chen Z. , Ren B. , Slatkin D. N. , Chapman D. , Shleifer M. , Staicu F. A. , Thomlinson W.
Published: July 2002

Status of the synchrotron-based computed tomography system, called multiple energy computed tomography (MECT), is described. MECT, that uses monochromatic beams from the X17 superconducting wiggler beam line at the National Synchrotron Light Source, will be used for imaging the human head and neck. An earlier prototype MECT produced images of phantoms and living rodents. This report summarizes the studies with the prototype, and describes the design, construction, and test results of the clinical MECT system components.
Physics of ion beam plasma and problems of intensive ion beam transportation (invited)a)
Authors: Soloshenko I. A.
Published: July 2002

Studies considering the problem of intensive ion beam transportation on large distances are performed in the Institute of Physics, including three main aspects: (1) space charge compensation of a stationary steady state beam, (2) dynamic decompensation of a beam space charge resulting from the current modulation owing to ion source plasma instabilities, and (3) collective processes. The results presented show the summary of plasma studies regarding the positive ion beams in the absence of external fields. These results make possible the numerical simulations or the qualitative predictions of the main properties for the transported beams (boundary particles trajectories, spatial distributions of static and variable fields, emittance, etc.).
Improved operation of the Michelson interferometer electron cyclotron emission diagnostic on DIII-D
Authors: Austin M. E. , Ellis R. F. , Doane J. L. , James R. A.
Published: July 2002

The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and a reduction of calibration error from 15% to 5%. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter-wavelength frequency and very stable transmission characteristics over time. Further reduction in error was realized through special signal processing of the calibration and plasma interferograms.
The transport properties of nanocrystalline SrCe0.95Yb0.05O3 thin films
Authors: Kosacki Igor , Anderson Harlan U.
Published: July 2002

The results of electrical transport measurements on nanocrystalline SrCe0.95Yb0.05O3 thin films are presented. Dense SrCe0.95Yb0.05O3 thin films with 30–70 nm grain size have been obtained using a spin-coating technique. These films exhibit about 103 higher electrical conductivity when compared with the bulk polycrystalline material. The grain size of thin films is stable to temperatures as high as 1000 °C since no grain-coarsening was observed. These unique electrical properties of nanocrystalline SrCe0.95Yb0.05O3 thin films are attributed to a dominant role of grain boundaries and/or interfaces.
Formation of self-assembled InP islands on a GaInP/GaAs(311)A surface
Authors: Reaves C. M. , Pelzel R. I. , Hsueh G. C. , Weinberg W. H. , DenBaars S. P.
Published: July 2002

The coherent Stranski–Krastanov growth mode is used to create selfassembled InP islands on GaInP/GaAs(311)A surfaces. The resulting islands on (311)A surfaces have a base width distribution peaked in the range of 600–800 Å in contrast to a distribution peaked at 1200 Å for islands on (100) surfaces. In addition on the (311)A surfaces, there is a bimodal island height distribution peaked at 15 and 50 Å. For the (311)A surfaces, the islands are significantly smaller and more dense (∼1010 islands/cm2) than the islands formed on (100) surfaces (∼109 islands/cm2). Despite these differences in the islands formed on the two surfaces, the growth occurs similarly for the two surfaces, with the formation of three different types of islands distinguished primarily by height.
Measurement of single interface trap capture cross sections with charge pumping
Authors: Saks N. S.
Published: July 2002

A technique has been developed using charge pumping to determine electron and hole capture cross sections of individual interface traps in small silicon metal–oxide–semiconductor transistors. Values for both cross sections are ≈10−16 cm2 for the particular trap measured.
14.3 W quasicontinuous wave front-facet power from broad-waveguide Al-free 970 nm diode lasers
Authors: Al-Muhanna A. , Mawst L. J. , Botez D. , Garbuzov D. Z. , Martinelli R. U. , Connolly J. C.
Published: July 2002

Wide-stripe, 0.97 μm emitting Al-free InGaAs(P)/InGaP/GaAs broad-waveguide separate confinement heterostructure quantum-well lasers demonstrate a record value for quasicontinuous wave (QCW) output power: 14.3 W (100-μm-wide stripe, 100 μs-wide pulses); and reach catastrophic optical mirror damage (COMD) in QCW operation at an optical power density of 22.5 MW/cm2; that is, 40% higher than COMD levels in cw operation. The devices have low internal losses (αi=1 cm−1) and high external differential quantum efficiency (86% for 2-mm-long lasers), and exhibit only 10–20 °C temperature rises in the active region at 10 W QCW power. We also show that long-cavity, large-contact-area devices exhibit relatively little spectral broadening with increased output power.
Charge carrier mobility in poly(p-phenylenevinylene) studied by the time-of-flight technique
Authors: Lebedev E. , Dittrich Th. , Petrova-Koch V. , Karg S. , Brütting W.
Published: July 2002

The charge carrier transport in poly(p-phenylenevinylene) (PPV) is investigated by the time-of-flight technique. Mobilities of positive carriers in PPV are determined and the dispersive character of transport is established. The dispersion parameters are analyzed in the frame of a multiple trapping model. The drift mobility of the positive carriers is in the range of 10-5 cm2/V at room temperature for an electric field of 105 V/cm and increases with increasing field and temperature. The mobility shows thermally activated behavior with an activation energy of about 0.75 eV at zero field. It is shown that the experimental results can be interpreted by polaron transport.
Growth of HgCdTe and CdTe(331)B on germanium substrate by molecular beam epitaxy
Authors: Zanatta J. P. , Duvaut P. , Ferret P. , Million A. , Destefanis G. , Rambaud P. , Vannuffel C.
Published: July 2002

The choice of germanium as a substrate for CdTe and HgCdTe (MCT) epitaxial films is discussed. Ge appears to be a good candidate to solve the weakness of CdTe homosubstrates. Direct growth of CdTe(331) B 4° off epitaxial films was achieved on a Ge (001) substrate tilted 8° around [11̄0] by molecular beam epitaxy (MBE). Hence MCT(331) 4° off MBE epilayers were grown and characterized. The surface morphology was smooth and mirrorlike. X-ray double-crystal rocking curve on (331) planes showed full-width at half-maximum of 130 arc sec. Transmission electron microscopy is also reported to show the misfit accommodation at the CdTe/Ge interface; two domains were observed close to the interface but only a (331) orientation remained after a 50-nm-thick growth. The first photodiodes on MCT on Ge were fabricated and exhibited high performances: for a cutoff wavelength value of 5.24 μm at T=77 K, the shunt impedance measured was 6.6×109 Ω and the R0A product was 1.8×105 Ω cm2.
Gettering of iron by oxygen precipitates
Authors: Hieslmair H. , Istratov A. A. , McHugo S. A. , Flink C. , Heiser T. , Weber E. R.
Published: July 2002

In order to better understand and model internal gettering of iron in silicon, a quantitative investigation of iron precipitation in silicon containing different oxygen precipitate densities was performed. The number of iron precipitation sites was obtained from the iron precipitation kinetics using Ham’s Law. At low temperatures, the iron precipitate density corresponded to the oxygen precipitate density. A strong temperature dependence of the iron precipitate density was observed for the samples with larger oxygen precipitate densities. These data were used to simulate iron precipitation during a slow cool. From those simulations, optimal cooling rates were obtained for different silicon materials assuming various iron precipitation site densities in the epitaxial layer.
Pinning of daisy modes in optically pumped vertical-cavity surface-emitting lasers
Authors: Pereira S. F. , Willemsen M. B. , van Exter M. P. , Woerdman J. P.
Published: July 2002

We have observed stable single-mode oscillation of optically pumped vertical-cavity surface-emitting lasers (i.e., without fabricated aperture) in several high-order daisy modes. The surprising stability of the nodal lines of a daisy mode is explained as being due to the combined action of many microscopic defects; when a daisy mode is moved across the wafer, the effective correlation length of the orientation of the pinning is of the order of 1 μm.
The Ge–C local mode in epitaxial GeC and Ge-rich GeSiC alloys
Authors: Weber W. H. , Yang B.-K. , Krishnamurthy M.
Published: July 2002

The Raman signature of the local Ge–C mode for substitutional C is identified as a narrow line (8 cm−1 full width at half maximum) near 530 cm−1 in alloy films of Ge1−yCy (0⩽y⩽0.07) grown on Ge (100) substrates by low-temperature (200 °C) molecular beam epitaxy. The intensity of the Ge–C line relative to the c-Ge line suggests that only a small fraction of the nominal C is in substitutional sites. In ternary alloys of Ge1−x−ySixCy with x=0.1 and 0.2 and y=0.03, the Ge–C mode disappears, suggesting a strong bias towards C bonding with Si as opposed to Ge. In Ge1−xSnx films the Ge–Sn mode is seen at 263 cm−1.
Noncontact nanolithography using the atomic force microscope
Authors: Wilder Kathryn , Quate Calvin F. , Adderton Dennis , Bernstein Robert , Elings Virgil
Published: July 2002

We have demonstrated that the atomic force microscope (AFM) operating in air may be used to pattern narrow features in resist in a noncontact lithography mode. A micromachined AFM cantilever with an integrated silicon probe tip acts as a source of electrons. The field emission current from the tip is sensitive to the tip-to-sample spacing and is used as the feedback signal to control this spacing. Feature sizes below 30 nm have been patterned in 65-nm-thick resist and transferred through reactive ion etching into the silicon substrate. We show that the same AFM probe used for noncontact patterning can be used to image the sample. In addition to eliminating the problem of tip wear, this noncontact system is easily adapted to multiple-tip arrays where each cantilever has an integrated actuator to adjust the probe height.
A vertical injection blue light emitting diode in substrate separated InGaN heterostructures
Authors: Song Y.-K. , Diagne M. , Zhou H. , Nurmikko A. V. , Carter-Coman C. , Kern R. S. , Kish F. A. , Krames M. R.
Published: July 2002

A vertical injection, light emitting InGaN quantum well diode has been demonstrated by separating the nitride heterostructure from its sapphire substrate by ultraviolet laser photoablation within a process scheme that allows transferring the devices to a host substrate. The incorporation of a dielectric multilayer stack to the device is shown to be a first practical step towards a resonant cavity light emitting diode.
Greatly enhanced soft x-ray generation from femtosecond-laser-produced plasma by using a nanohole-alumina target
Authors: Nishikawa Tadashi , Nakano Hidetoshi , Uesugi Naoshi , Nakao Masashi , Masuda Hideki
Published: July 2002

By making an array of nanoholes on an alumina target, x-ray emission from laser-produced plasma can be greatly enhanced even in soft x-ray energy regions (<0.25 keV). X-ray fluence enhancement around 30 times was achieved in the 5–25 nm wavelength range. The enhancement increases as the ionization level of Al becomes higher and the x-ray wavelength becomes shorter. Over 50-fold enhancement was obtained at a soft x-ray wavelength around 6 nm, which corresponds to the emission from Al8+,9+ ions. X-ray pulse duration was 17 ps, which is much shorter than that obtained by using the prepulse technique.
A microcantilever-based alcohol vapor sensor-application and response model
Authors: Jensenius Henriette , Thaysen Jacob , Rasmussen Anette A. , Veje Lars H. , Hansen Ole , Boisen Anja
Published: July 2002

A recently developed microcantilever probe with integrated piezoresistive readout has been applied as a gas sensor. Resistors, sensitive to stress changes, are integrated on the flexible cantilevers. This makes it possible to monitor the cantilever deflection electrically and with an integrated reference cantilever background noise is subtracted directly in the measurement. A polymer coated cantilever has been exposed to vapors of various alcohols and the resulting cantilever response has been interpreted using a simple evaporation model. The model indicates that the cantilever response is a direct measure of the molecular concentration of alcohol vapor. On the basis of the model the detection limit of this cantilever-based sensor is determined to be below 10 ppm for alcohol vapor measurements. Furthermore, the time response of the cantilever can be used to distinguish between different alcohols due to a difference in the evaporation rates.
Suppression of magnetic-field pulse-induced magnetization precession by pulse tailoring
Authors: Bauer M. , Lopusnik R. , Fassbender J. , Hillebrands B.
Published: July 2002

Short magnetic-field pulses may be used in the near future to change the magnetization state in magnetic storage devices. In order to minimize the time required for this process, and thus to maximize the switching speed of such devices, the magnetization precession after the termination of the magnetic-field pulse needs to be suppressed to a maximum degree. It is demonstrated experimentally that the appropriate adjustment of the field pulse parameters may lead to a full suppression of the magnetization precession immediately upon termination of the field pulse.
Low resistance Ti/Pt/Au ohmic contacts to p-type GaN
Authors: Zhou L. , Lanford W. , Ping A. T. , Adesida I. , Yang J. W. , Khan A.
Published: July 2002

Electrical properties of Ti (15 nm)/Pt (50 nm)/Au (80 nm) contacts on moderately doped p-GaN (NA=3.0×1017 cm−3) are reported. Linear current–voltage characteristics were observed after annealing the contacts for 1 min at temperatures above 700 °C. The best ohmic contacts were obtained after annealing in a N2 ambient at 800 °C for 2 min. These contacts exhibited a specific contact resistance Rc of 4.2×10−5 Ω cm2 and contact resistivity ρc of 21 Ω mm. Possible mechanisms for the lower contact resistivity of Ti/Pt/Au contacts are discussed. The processing for the Ti/Pt/Au ohmic contacts is compatible with routine fabrication steps for GaN devices.
Heavy photon dispersions in photonic crystal waveguides
Authors: Astratov V. N. , Stevenson R. M. , Culshaw I. S. , Whittaker D. M. , Skolnick M. S. , Krauss T. F. , De La Rue R. M.
Published: July 2002

Heavy photon dispersion curves exhibiting group velocities suppressed by two orders of magnitude are measured directly for deeply etched AlGaAs waveguide structures by means of surface coupling techniques. It is shown that due to the wave vector-selective nature of surface coupling, such techniques permit the excitation of modes of specific, known dispersion in photonic crystal waveguides. Coupling to regions of very strong anomalous dispersion is demonstrated, with potential to be developed into a method for excitation of gap solitons.
Ultrasonic imaging, particle detection, and V(z) measurements in molten zinc using focused clad buffer rods
Authors: Ihara I. , Jen C.-K. , Ramos França D.
Published: July 2002

Ultrasonic imaging, particle detection, and V(z) measurements have been performed using focused clad buffer rods in molten zinc at temperature more than 600 °C. The focused ultrasonic waves are generated by a spherical or cylindrical acoustic lens which is fabricated at the end of the clad buffer rod. In order to evaluate its focusing ability, several experiments are carried out at 10 MHz in a pulse-echo mode. The lateral resolution at the focus of the spherical acoustic lens in molten zinc is quantitatively examined and compared with that in water using a thin stainless wire with a diameter of 380 μm. High resolution ultrasonic imaging is carried out by the common C-scan technique. The signal-to-noise ratio of the reflected signals from the flat sample surface at the focus is better than 35 dB. Ultrasonic images are obtained from the amplitude and time delay variations of the reflected signals. An attempt has also been made to detect particles suspended in molten zinc. Backscattered signals from particles are clearly visible at the focal region of the lens. For quantitative materials evaluation, V(z) curve measurements are performed using both spherical and cylindrical surface lenses and the leaky surface acoustic wave velocity of a ceramic (SiC) plate immersed in molten zinc is successfully determined.
Optimization of the diffuse reflectance of pigmented coatings taking into account multiple scattering
Authors: Vargas William E.
Published: July 2002

The optical properties of particulate coatings consisting of homogeneous rutile or anatase pigments randomly distributed through a polymeric binder are considered in the solar spectral range. The sizes of the pigments leading to the highest values of the effective scattering coefficients per unit length are established from a multiple scattering approach. Also, taken into account are boundary reflections of the diffuse radiation at the interfaces of the particulate coatings. Optimizations of the solar reflectance of pigmented coatings are also carried out. Fairly good agreement is found when comparing to solar reflectance values obtained from spectroscopic measurements involving an integrating sphere attachment.
Hybrid simulations of collapse of Alfvénic wave packets
Authors: Buti B. , Velli M. , Liewer P. C. , Goldstein B. E. , Hada T.
Published: July 2002

Nonlinear dynamics, of large-amplitude circularly polarized Alfvénic wave packets, is investigated using a one-dimensional hybrid model. Kinetic effects such as finite-Larmor radius and nonlinear Landau damping, which become significant for plasmas with β∼1, are appropriately accounted for in these high-resolution hybrid simulations. Spatio-temporal evolution, of the left-hand polarized (LHP) wave packets, shows that they collapse because of the decreasing dispersive effects. However, singularities are arrested by the wave–particle interactions. At some critical time tc, which depends on the plasma β and the initial amplitude of the wave packet, we observe a turning point. At this turning point, the polarization changes from LHP to RHP (right-hand polarized). The wave packet then starts broadening due to increasing dispersion associated with the RHP. Implications of collapse of the magnetic structures are briefly discussed.
On the calculation of the geometric factor in a van der Pauw sheet resistance measurement
Authors: Chan Winston K.
Published: July 2002

A short and fast iterative algorithm for calculating the geometric factor in a van der Pauw sheet resistance measurement is described. Fractional errors below 10−14 are obtained with less than 50 iterations for any value of the resistance ratio RAB,CD/RBC,DA.
Plug “n” play scanning probe microscopy
Authors: Michely Thomas , Kaiser Markus , Rost Marcel J.
Published: July 2002

A new concept of scanning probe microscopy allows the investigation of arbitrarily positioned and oriented, possibly curved locations situated at large and immobile objects, which cannot be isolated from the environment. The concept is based on the beetle type scanning probe microscope and uses, as a key element, magnetic forces which increase the pressure at the contacts of microscope and object. The magnetic forces are shown to greatly decrease the sensitivity of the microscope to vibrations and acoustic noise from the environment. Sufficiently large magnetic forces make the microscope operation independent from orientation and thereby relieve a decisive constraint for imaging application. The capabilities of the new concept are exemplified for a plug “n” play scanning tunneling microscope.