bluuebunny/crossref_metadata_2025 huggingface dataset:
Double heterostructure Pb1-xSnx Te–PbTe lasers with cw operation at 77 K
Authors: Groves S. H. , Nill K. W. , Strauss A. J.
Published: January 2004

Diode lasers that operate cw at 77 K have been made from a Pb0.88Sn0.12 Te–PbTe double heterostructure grown by liquid phase epitaxy. Junction diffusion during growth has been prevented by the use of Tl-doped PbTe substrates. The wavelength emitted in cw operation has been temperature tuned from 10.5 μm at 12 K to less than 8.2 μm at 80 K, a range of nearly 280 cm−1. The cw threshold current density increases from 1.6 × 103 A/cm2 at 12 K to 4.2 × 103 A/cm2 at 77 K. The measured cw power is 10 mW in four modes at 12 K (1.8 × 104 A/cm2) and 1.2 mW in a single mode at 77 K (7.5 × 103 A/cm2).
High-repetition-rate copper iodide laser
Authors: Liberman I. , Babcock R. V. , Liu C. S. , George T. V. , Weaver L. A.
Published: January 2004

Quasicontinuous pulsed laser output at 5106 and 5782 Å is reported from 600°C copper iodide discharges at repetition rates near 8 kHz. In single pulses 35 μJ cm−3 has been observed, indicating that 0.28 W cm−3 volumetric power density can be achieved.
Time resolved absolute x-ray measurements on laser-produced plasmas
Authors: Key M. H. , Eidmann K. , Dorn C. , Sigel R.
Published: January 2004

The absolute intensity of soft x-ray emission from laser-generated plasmas has been studied with vacuum photodiodes of 1.0-nsec time resolution.
Measurements of charge propagation in Si3N4 films
Authors: Yun B. H.
Published: January 2004

A new experimental technique is described, which measures the injection and propagation of charge in the Si3N4 film of an MNOS structure caused by a pulsed electric field. Contrary to the widely held contention that the electrons injected from the Si are trapped in and very near the SiO2–Si3N4 interface, a contention resulting from the assumption that the trap density near this interface usually far exceeds the number of injected electrons, this work finds that the spatial distribution of the trapped electrons extends deep into the Si3N4 film. In fact, the centroid of the spatial distribution of the trapped electrons in a Si3N4 film ≃500 Å thick can be as much as 150 Å or more from the SiO2–Si3N4 interface, indicating that the span of the distribution extends across almost the entire thickness of the film with an average density of trapped electrons in the order of 3 × 1018/cm3. It is shown that, in general, the centroid of the trapped charge distribution in the Si3N4 film of a given device structure is a function of the applied field and its duration.
A nitrogen ion laser pumped by charge transfer
Authors: Collins C. B. , Cunningham A. J. , Stockton M.
Published: January 2004

The first nitrogen ion laser pumped by charge transfer from He2+ is reported in this work. Intense laser emission in the violet at 427 nm has been observed and found to have a linewidth less than 0.3 nm. The pumping ion, He2+, was produced by discharge of a fast-pulsed electron beam gun, APEX-1, into 7 atm of a mixture of helium and nitrogen. Excitation current densities were 1.4 kA/cm2 at 1 MV over a 1 × 10 cm transverse geometry. Under these conditions, the efficiency of the emission of 427-nm laser radiation was found to be 1.9% relative to the energy lost by the electron beam in the radiating volume.
R-I profiling: A new technique for measuring semiconductor doping profiles
Authors: Glover G. H. , Tantraporn W.
Published: January 2004

A new technique for measuring semiconductor doping profiles is described. The method is based on measurement of the isothermal space-charge resistance R as a function of reverse current I in an avalanching abrupt junction. It is closely analogous to the usual C-V profiling techniques but is complementary in the information gained. The new method has a minimum depth limitation set by the depletion region width at breakdown, but (in principle) has no maximum depth limit. Analysis of the technique and typical results using GaAs IMPATT diodes are presented.
Optically pumped cw Hg laser at 546.1 nm
Authors: Djeu N. , Burnham R.
Published: January 2004

cw laser oscillation has been achieved on the 546.1-nm line in Hg I using an optical pumping scheme. The potentials of this laser are discussed.
Liquid phase epitaxial (LPE) grown junction In1−xGaxP (x∼0.63) laser of wavelength λ∼5900 Å (2.10 eV, 77°K)
Authors: Hitchens W. R. , Holonyak N. , Lee M. H. , Campbell J. C. , Coleman J. J. , Groves W. O. , Keune D. L.
Published: January 2004

Laser operation (77 °K) of In1−xGaxP LPE p-n junctions is demonstrated at λ∼5900 Å (2.10 eV, yellow). The junctions are prepared by the sequential growth (on GaAs1−yPy substrates) of first an n-type layer and then a Zn-doped p-type layer (not compensated). During growth of the p-type layer, Zn diffuses slightly (at reduced concentration) into the first layer, yielding a thin compensated active layer. The structure which results approximates in operation the behavior of a single heterojunction. Although the threshold for the laser operation of these devices is fairly high, it is demonstrated, nevertheless, that In1−xGaxP LPE grown junctions can be operated as lasers and, furthermore, at wavelengths λ ≲ 5900Å.
Microwave surface resistance of superconducting Mo0.75Re0.25
Authors: Yasaitis J. A. , Rose R. M.
Published: January 2004

A Mo0.75Re0.25 alloy endplate was tested on a Nb TE011 mode microwave cavity resonant at 11.2 GHz. An upper bound for the surface resistance of 2.8 μΩ and a lower bound of 102 G for the microwave magnetic breakdown field were established for the alloy plate. Comparison of these results to current requirements for a superconducting linear accelerator demonstrated the potential feasibility of this alloy as a practical alternative to Nb and Pb for accelerator applications. This is the first alloy shown to be a potential alternative to Nb and Pb and arguments are presented which indicate possible practical advantages of Mo0.75Re0.25 over Nb and Pb.
Determination of wall mobility in garnets by high-frequency magnetic susceptibility measurements
Authors: Hashimoto Takasu , Miyoshi Taisuke , Hamasaki Tatsuichi , Okada Toshihiro , Suemune Yasutaka , Hattanda Takatsugu
Published: January 2004

Magnetic domain wall mobilities in four kinds of bubble garnets are determined by the high-frequency magnetic susceptibility measurement and are almost in agreement with bubble mobilities in these garnets obtained directly by a pulsed field gradient technique.
Noncollinear acousto-optic filter with large angular aperture
Authors: Chang I. C.
Published: January 2004

A new type of noncollinear acousto-optic filter with large angular aperture is described. By an appropriate choice of acoustic wave propagation direction, the momentum mismatch caused by the angular deviation of the incident light from the matching condition in a noncollinear interaction can be compensated by the angular change of optical birefringence. A TeO2 noncollinear acousto-optic filter was constructed that had a half-power bandwidth of 40 Å at an f/4 (±7°) aperture. Tuning from 700 to 450 nm is obtained by changing the acoustic frequency from about 100 to 180 MHz. About 95% maximum transmission is obtained with an electrical power density of 1 W/cm2 applied to the transducer.
Stabilizing effect produced by acoustic surface waves on collinearly propagating light beams
Authors: Alippi A.
Published: January 2004

The interaction of light with the field of the alternating strains produced by inhomogeneous acoustic surface waves may enable one to guide light beams underneath the surface of solid media. The evaluation is made of the convergence which may be attained for light beams which collinearly propagate with the acoustic waves. Maximum spreading angles are obtained which are equal to a fractional variation of the refractive index induced by the stress wave of the order of 0.1 Δn/n.
Dependence of ion acceleration on limiting current in relativistic electron beams
Authors: Straw David C. , Miller R. B.
Published: January 2004

A 2-MeV 15-kA 45-nsec electron beam was used to obtain high-energy deuterons when injected into a chamber filled with neutral deuterium at low pressure. It was found that ion acceleration did not occur until the electron current exceeded the space-charge limiting current, the threshold established by the acceleration model of Olson. The limiting current was varied through its dependence on the ratio of guide tube radius to injected electron beam radius. The maximum deuteron energy was measured to be 4.5 MeV for the largest guide tube to beam radius ratio. An increasing average ion energy with an increasing radius ratio was also observed.
Carrier mobility profiles for low-dose boron-implanted layers
Authors: Darwish M. Y. , Luginbühl H. W.
Published: January 2004

Carrier concentration and mobility profiles of low-dose boron-implanted layers have been measured for several low-temperature heat treatments. It is found that sufficient activation of impurities can be obtained, but that significantly lower mobilities have to be expected.
Tunable far infrared methyl fluoride laser using transverse optical pumping
Authors: Brown Fielding , Kronheim Steven , Silver Eric
Published: January 2004

Some severe limitations of optically pumped superradiant FIR lasers (700-MHz linewidth, ragged pulse shape) may be overcome by using transverse optical pumping (TOP). Strong (∼500 W) lines have been produced in CH3F with linewidth <30 MHz, and cavity tuning has been achieved over a range of 460 MHz at 496 μm. Prospects for extending the tuning range and increasing the power are considered.
Oxidation studies of amorphous and crystalline germanium films by Auger spectroscopy
Authors: Fan John C. C. , Henrich Victor E.
Published: January 2004

Using Auger spectroscopy and ion-beam etching, we have studied the room-temperature oxidation of sputtered and electron-beam-evaporated germanium films. Large differences are observed between the oxygen profiles of sputtered and e-beam amorphous films. Sputtered amorphous films have only a very thin layer of oxide on the surface (4–5 Å), possibly because the presence of argon in the films inhibits further oxidation. In e-beam amorphous films, the heavily oxidized layer is also thin (7–8 Å), but some oxygen is present as far as 200 Å into the samples.
``Photoinduced relaxation'' in amorphous As–S films
Authors: Matsuda A. , Mizuno H. , Takayama T. , Saito M. , Kikuchi M.
Published: January 2004

The photoinduced motion of a As2S8 film-mica substrate system has been observed during He–Cd laser beam irradiation on the surface of the evaporated region. Experimental results using a prestressed mica substrate during the evaporation show that this phenomenon is a ``photoinduced relaxation'' effect.
Grating masks suitable for ion-beam machining and chemical etching
Authors: Tsang Won-Tien , Wang Shyh
Published: January 2004

By using the simultaneous exposure and development technique, high-resolution relief gratings with periods as small as 2400 Å have been produced which have grooves cleanly developed down to the substrate surface and exposing wide surface stripes with clearly defined, sharp and narrow photoresist ridges. Such gratings are suitable for use as masks in ion-beam machining and chemical etching. Results of chemically etched gratings into glass substrates with a 5000-Å period are presented and prospects of obtaining chemically etched gratings with shorter periods are discussed.
CuInSe2/CdS heterojunction photovoltaic detectors
Authors: Wagner Sigurd , Shay J. L. , Migliorato P. , Kasper H. M.
Published: January 2004

We report CuInSe2/CdS p-n heterojunction photovoltaic detectors which display uniform quantum efficiencies of up to ∼70% between 0.55 and 1.25 μ. Response times as short as 5 nsec have been observed. A weak electroluminescence (0.01% external quantum efficiency) peaking near 1.4 μ has also been observed at room temperature.
Temporary gratings on germanium
Authors: Wiggins T. A. , Salik Alfred
Published: January 2004

Diffraction gratings have been formed on the surface of germanium using two beams from a ruby laser inclined at an angle to each other. Grating spacings from 2 to 20 μm have been formed that appear to be present only during the illumination and no visible damage is observed. Subsequent illumination with a single beam produces no observable diffracted beams. Permanent gratings in damaged areas can be produced with more intense beams. The intensity of a diffracted order appears to depend on the product of the intensities of the incident beams. Several applications of the temporary grating are suggested.
Threshold reduction in Pb1−xSnx Te laser diodes through the use of double heterojunction geometries
Authors: Tomasetta L. R. , Fonstad C. G.
Published: January 2004

A systematic study has been made of the effect of the middle active region width in double heterojunction Pb1−xSnx Te/PbTe laser diodes on the lasing threshold. A fourfold reduction in pulsed threshold over that of comparable single heterojunction lasers is demonstrated in lasers having 4-μm-wide middle regions. A comparison is also made between lasers fabricated by liquid phase epitaxy using undoped melts and substrates, and using thallium-doped p -type PbTe layers; the latter is shown to yield thresholds as much as two times lower.
Temperature dependence of the absorption coefficient of GaAs and ZnSe at 10.6 μm
Authors: Skolnik L. H. , Lipson H. G. , Bendow B. , Schott J. T.
Published: January 2004

The temperature (T) dependence of the absorption coefficient β at 10.6 μm of Czochralski-grown high-resistivity GaAs and chemical vapor deposited (CVD) ZnSe is measured by laser calorimetry. Experimental data are compared with theoretical curves for intrinsic multiphonon absorption. The temperature dependence of β for GaAs is found to possibly exhibit multiphononlike behavior below ∼450°K, but deviates rapidly from theoretical predictions above ∼500°K. The latter effect may be attributed to an increase in free-carrier density via thermal ionization from a level near 0.37 eV. The absorption coefficient of CVD ZnSe is found to be independent of T over the temperature range investigated, and therefore this material appears to be impurity or surface loss dominated.
InAs spin-flip laser operation at 3 μm
Authors: Eng R. S. , Mooradian A. , Fetterman H. R.
Published: January 2004

Stimulated spin-flip Raman scattering in InAs has been achieved using an HF laser pump near the band-gap resonance. Thresholds were determined to be less than 20 W and conversion efficiency is estimated to be in excess of 20%.
Identification of the dominant diffusing species in silicide formation
Authors: Chu W. K. , Kraütle H. , Mayer J. W. , Müller H. , Nicolet M.-A. , Tu K. N.
Published: January 2004

Implanted noble gas atoms of Xe have been used as diffusion markers in the growth study of three silicides: Ni2Si, VSi2, and TiSi2. Backscattering of MeV He has been used to determine the displacement of the markers. We found that while Si atoms predominate the diffusion in VSi2 and TiSi2, Ni atoms are the faster moving species in Ni2Si.
Determination of saturation intensity in NH2D
Authors: Thielman L. , Davis L. W.
Published: January 2004

Saturated absorption of monochromatic radiation by a Doppler-broadened transition in NH2D has been measured as a function of intensity. The transition was Stark tuned into coincidence with the 10.6-μm P(20) line of a CO2 laser. We thereby determined the dependence of the saturation intensity on pressure (5–120 mTorr) and beam radius (0.70–1.25 mm).
Effect of bias field in a zinc-oxide-on-silicon acoustic convolver
Authors: Coldren L. A.
Published: January 2004

A monolithic acoustic surface wave parametric signal processor, fabricated with sputtered zinc oxide on an oxidized epitaxial n -on-n+ silicon substrate, is demonstrated. The dependence of the convolution output signal strength on applied gate bias is analyzed, and it is found that the maximum output occurs just before the semiconductor surface inverts, at which time the high-frequency capacitance-voltage characteristic has its maximum slope.
Efficient acousto-optic TE⇄TM mode conversion in ZnO films
Authors: Sasaki H. , Kushibiki J. , Chubachi N.
Published: January 2004

The TE⇄TM mode conversion by acoustic surface waves in a ZnO-film optical waveguide fabricated on a fused-quartz substrate is described. An efficient mode conversion as high as 88% has been accomplished in a waveguide with a film thickness of 5 μm at an acoustic frequency of 226 MHz and an acoustic power of 350 mW.
Filamentation of intense relativistic electron beams propagating in dense plasmas
Authors: Kapetanakos C. A.
Published: January 2004

It is observed that relativistic electron beams propagating in magnetized dense plasmas (np≫nb) split into filaments at low values of magnetic field. The beam filamentation is inhibited at higher values of magnetic field, but is affected only slightly with increasing beam ``temperature''. The instability is accompanied by intense microwave emission, the power of which increases exponentially with magnetic field.
Tunable spin-flip Raman scattering in mercury cadmium telluride
Authors: Sattler J. P. , Weber B. A. , Nemarich J.
Published: January 2004

Tunable spin-flip Raman scattering has been observed in Hg0.766Cd0.234Te using several CO2 laser lines near 9.5 μm to pump the crystal. The Stokes component with a maximum power output of about 1 W was tunable between 15 and 68 cm−1 from the pump frequency with magnetic fields between 4 and 21 kG. This corresponds to an average tuning rate of 3.4 cm−1/kG. The extrapolated zero-field g factor was measured to be |79|±3 yielding a conduction band-edge effective mass ratio of 0.0101±0.0005. Several factors suggest that the tunable radiation was stimulated.
Continuously tunable xenon laser at 1720 Å
Authors: Wallace Stephen C. , Dreyfus R. W.
Published: January 2004

We report the first continuously tunable vacuum ultraviolet laser emission in high-pressure xenon. By incorporating a dispersive element into the optical cavity, laser action was obtained over a 50-Å (1700-cm−1) range about a central wavelength of 1720 Å. A highly efficient pumping scheme allows the use of a 0.6-MeV electron accelerator delivering ≤ 10 J in a 3-nsec excitation pulse.
Determination of intervalley electron-phonon deformation potential constants in n -silicon by analysis of high electric field transport properties
Authors: Nash James G. , Holm-Kennedy James W.
Published: January 2004

The intervalley electron-phonon deformation potential constants in n -silicon were determined by fitting the theoretical high electric field transport properties (established using an ``exact'' solution to the Boltzmann transport equation) to those obtained experimentally at 77 K. The principal contribution to intervalley scattering under warm and hot electron conditions was found to come from a 680 K f -type phonon (Df=6.85×108 eV/cm for coupling to one other valley) with much weaker contributions from 210 K (Dg =0.7×108 eV/cm) and 130 K (Dg =0.6×108 eV/cm) low-energy g -type phonons. Good agreement was also obtained between the experimentally and theoretically determined repopulation versus field.
Bistable switching on gallium arsenide Schottky gate field-effect transistors
Authors: Rossel P. , Cabot J. J. , Graffeuil J.
Published: January 2004

A bistable switching phenomenon including a memory effect has been observed on a GaAs FET with Schottky gate. The characteristics of the two states of the transistor appear to be very different, the first having a high input impedance of the gate and the second Ohmic behavior of the gate. Transitions between these two states are achieved through negative or positive pulses applied to the gate. The transition time is less than 1 μsec. Each state remains stable over a period of weeks.
Surface state band on GaAs (110) face
Authors: Gregory P. E. , Spicer W. E. , Ciraci S. , Harrison W. A.
Published: January 2004

Careful photoemission studies of surface states on the cleavage GaAs (110) detect no filled states in the band gap. However, empty states pin the surface Fermi level on n -type GaAs at midband gap. Filled states are placed below the valence-band maximum and empty surface states in the upper half of the band gap. Calculations, using the bond orbital model, agree with these results and associate the empty and filled bands with Ga and As, respectively.
Temporally coincident ultrashort pulses from synchronously pumped tunable dye lasers
Authors: Royt T. R. , Faust W. L. , Goldberg L. S. , Lee Chi H.
Published: January 2004

The temporal and spectral character of the picosecond pulses from a dye laser which was synchronously pumped by a frequency-doubled mode-locked Nd:glass laser was studied with an ultrafast streak camera. For matched pump and dye laser cavity lengths, the observed dye pulses were of 15-psec duration and were in very close temporal synchronism with the pump pulses. For deviations from match >0.1 mm, severe aberrations in pulse character began to occur. Spectral tuning of the dye laser was achieved with a narrow-gap etalon. The utility of such lasers in producing two independently tunable time-synchronized ultrashort pulses for parametric frequency generation and spectroscopic studies is discussed.
A 1.4–4-μm high-energy angle-tuned LiNbO3 parametric oscillator
Authors: Herbst R. L. , Fleming R. N. , Byer R. L.
Published: January 2004

We have operated a high-gain angle-tuned singly resonant LiNbO3 parametric oscillator pumped directly at 1.06 μm by a Q -switched Nd:YAG laser. The oscillator angle tunes from degeneracy and operates over the entire 1.4–4.4-μm range. Output energies of greater than 1 mJ/pulse at 5 pps have been observed with a 15% energy conversion efficiency. The key to this device is the large LiNbO3 crystals fabricated from new [01.4] grown boules. Crystals up to 15 mm in diameter and 5 cm in length have been cut at the nominal 47° orientation. These crystals will potentially handle over 2 J of optical energy at 1.06 μm.
The electrical effect on Schottky barrier diodes of Si crystallization from Al–Si metal films
Authors: Reith T. M. , Schick J. D.
Published: January 2004

The barrier height of n-Si Schottky contacts made with Si-doped Al metallization is observed to vary from 0.79±0.02 V to 0.89±0.02 V after heat treatments at temperatures from 400 to 550°C. Identical diodes made with pure Al metallization have φB =0.68±0.02 V. The scanning electron microscope in the electron-beam-induced-current mode is used to show that the upward shift in φB is due to a thin layer of p -doped Si, probably continuous, which is grown from the Al–Si metallization on the n contacts. The discretely distributed Si mesas and precipitates reported by other investigators as crystallizing out of the metallization are observed also, but are believed to play a limited electrical role.
Quantum interference effects in high-transition-temperature thin-film materials
Authors: Palmer David William , Notarys H. A. , Mercereau J. E.
Published: January 2004

Superconducting quantum interferometers with operating temperatures of up to 17°K have been fabricated from thin films of Nb3Sn and NbN by means of photolithographic and argon ion etching techniques.
Dietary behaviour of German adults differing in levels of sport activity
Authors: Beitz Roma , Mensink Gert BM , Henschel Yvonne , Fischer Beate , Erbersdobler Helmut F
Published: January 2004

Objective:

To analyse the dietary behaviour of persons engaging in different levels of sport activity.

Design:

A cross-sectional survey analysis.

Setting:

A population-based sample of German adults.

Subjects:

A total of 1756 men and 2254 women participating in the German National Health Interview and Examination Survey and the integrated German Nutrition Survey 1998.

Results:

Among both genders, the median micronutrient intakes of active persons were more preferable than those of sedentary persons when German current reference values were used as a criterion. The median nutrient densities were also higher in the diet of active persons, especially those of vitamin E, calcium, magnesium, and among women also those of folate and vitamin C. On average, active persons consumed higher amounts of fruit/vegetable juice, drinking water, milk products (including cheese) and fruits. Active men additionally consumed higher amounts of vegetables and vegetable fat. The contribution of dietary supplements to the total nutrient intake was 3%, on average, for active men and women. Compared with sedentary persons, this contribution was significantly higher for vitamins, and among men also for calcium and magnesium.

Conclusion:

There was no indication of an impaired micronutrient intake of active and moderately active persons compared with sedentary persons.
Reliability and validity of a food-frequency questionnaire for Chinese postmenopausal women
Authors: Xu Liangzhi , Dibley Michael J , D'Este Catherine
Published: January 2004

Objectives:

(1) To determine the reliability and validity of a food-frequency questionnaire (FFQ) for use in epidemiological research in postmenopausal women; and (2) to compare the volume estimation (VE) and weight estimation (WE) method of administration of this questionnaire.

Design:

An initial list of foods was derived and modified after pre-testing in 22 subjects. Test-retest reliability was assessed in 21 subjects who had repeat administrations of the questionnaire 14 days apart (FFQ1, FFQ2). The validity of the FFQ was assessed by comparing nutrient intakes with those from a 4-day food record.

Setting:

Chengdu, People's Republic of China.

Subjects:

Twenty-two postmenopausal women (50–70 years) were recruited from The Second University Hospital, West China University of Medical Sciences, Chengdu and participated in the pre-test. Another 21 women (50–70 years) were randomly selected from the general population of all five districts of Chengdu and participated in the reliability and validity sub-studies.

Results:

Energy, protein, carbohydrate, magnesium and sodium intakes in this sample were less than the Recommended Dietary Allowances (RDAs) for 45–70-year-old women in China. Intake of non-cooking fat was higher than the Chinese RDA. Pearson correlation coefficients and intra-class correlation coefficients (ICCs) for reliability of the VE FFQ ranged from 0.51 to 0.85 and from 0.51 to 0.81, respectively; for the WE FFQ, they ranged from 0.22 to 0.86 and from 0.21 to 0.81. Correlation coefficients and ICCs for validity of the WE FFQ ranged from 0.36 to 0.69 and from 0.34 to 0.57, respectively; corresponding values for the VE FFQ were −0.30 to 0.65 and −0.14 to 0.65.

Conclusions:

Both the VE and WE FFQs were reliable and valid except for sodium intake. The VE FFQ provided more valid estimates of nutrient intakes than did the WE FFQ.
Dietary selenium intake by men and women in high and low selenium areas of Punjab
Authors: Hira Charanjeet K , Partal Kulprakash , Dhillon KS
Published: January 2004

Objective:

To determine the selenium intake of adults residing in high and low selenium areas of rural Punjab.

Design:

All food samples consumed by the subjects were collected and analysed for selenium content. Based on food intake data and selenium content of foods, the selenium intake of the subjects was calculated. Hair, fingernails and urine samples from a sub-sample of subjects were collected and analysed for selenium.

Setting:

Three villages from the selenium-endemic area of Nawan Shahr District and two villages from the non-endemic area of Ludhiana District, Punjab, India, were covered.

Subjects:

Forty families from each of the two areas, with one adult male and one adult female in the age range of 20–40 years, were surveyed. Thus a total of 80 men and 80 women constituted the study sample.

Results:

In the selenium-endemic area, the average selenium intake of both men and women was more than nine times that in the non-endemic area and exceeded the maximum tolerable limit in more than 60% of men. Mean selenium content of the hair, nails and urine of both men and women was tens of times higher than in the non-endemic area.

Conclusions:

High selenium intake in the endemic area resulted in high selenium content in the hair, nails and urine of men and women. In addition, clinical symptoms of selenium toxicity were also observed in some of the subjects. Selenium intake in the non-endemic area was marginally below the suggested value. Based on the study results, steps need to be taken to educate the public in the endemic area to avoid selenium toxicity.
Consistency of use of plant stanol ester margarine in Finland
Authors: Simojoki Meri , Luoto Riitta , Uutela Antti , Boice John D , McLaughlin Joseph K , Puska Pekka
Published: January 2004

Objective:

The aims of this study were to investigate the consistency of use of plant stanol ester margarine and to characterise consistent and inconsistent users.

Design:

A cohort of plant stanol ester margarine users was established based on 14 national surveys conducted by the National Public Health Institute in Finland between 1996 and 1999. A follow-up study questionnaire was developed and sent to 1294 users in 2000.

Setting:

Subjects who reported using plant stanol ester margarine in both the original survey and the follow-up study were classified as consistent users, and the rest as inconsistent users.

Subjects:

The study population consisted of 1094 subjects aged 18–87 years, 590 men and 504 women.

Results:

There were 357 (33%) consistent and 737 (67%) inconsistent users of plant stanol ester margarine in the study population. Consistent users were more likely to be men and to have a higher household income than inconsistent users. Both consistent and inconsistent users were predominantly middle-aged persons with a healthy lifestyle and diet as well as a history of cardiovascular disease. Healthfulness was the main factor affecting bread spread choice among 94% of the consistent users and 59% of the inconsistent users.

Conclusions:

The use of plant stanol ester margarine is more often inconsistent than consistent. There is nevertheless a relatively large subgroup of long-term users of plant stanol ester margarine. It is important to examine the health effects especially among these regular users.
Consumption of foods by young children with diagnosed campylobacter infection – a pilot case–control study
Authors: Cameron Scott , Ried Karin , Worsley Anthony , Topping David
Published: January 2004

Objective:

To determine whether parentally reported habitual intake of specific foods differed between children with diagnosedCampylobacter jejuniinfection and children of a comparison group without diagnosed infection.

Design, setting and subjects:

Information was collected from the parents or primary caregivers of South Australian children aged 1–5 years with diagnosedC. jejuni(cases,n=172) and an age- and gender-matched group of uninfected children (controls,n=173). Frequency of consumption of 106 food and drink items was determined for the preceding two months by food-frequency questionnaire. Four children in the control group had recorded diarrhoeal episodes during the assessment period and were excluded, so 169 responses were evaluated for this group. Information was gathered on possible confounders including socio-economic status. Response frequencies were classified into three levels of consumption (rarely, weekly or daily) and statistical comparison was made by frequency of consumption of foods versus the ‘rarely’ classification for cases and controls, respectively.

Results:

Frequency of consumption of most foods, including starchy foods and fruits and vegetables, did not differ between cases and controls. However, reported consumption of eight food items (block and processed cheese (slices and spread), salami/fritz (a form of processed sausage), chicken nuggets, pasteurised milk, fish (canned or fresh) and hot French fries) was significantly higher by controls.

Conclusions:

The hypothesis that reported consumption of starchy foods was lower by cases than by controls was not supported by the data. However, consumption of some processed and unprocessed foods was higher by controls. Some of these foods have established bactericidal actionsin vitrothat may indicate a possible mechanism for this apparent protection.
Nutrition and lifestyle in relation to bowel movement frequency: a cross-sectional study of 20 630 men and women in EPIC–Oxford
Authors: Sanjoaquin Miguel A , Appleby Paul N , Spencer Elizabeth A , Key Timothy J
Published: January 2004

Objective:

To investigate the relationships between nutritional and lifestyle factors and bowel movement frequency.

Design:

Cross-sectional analysis using data from a prospective study. Mean numbers of bowel movements were calculated in relation to a range of factors. In addition, individuals were categorised according to frequency of bowel movements: fewer than 7 per week (‘less than daily’) versus 7 or more per week (‘daily’), and odds ratios were calculated from logistic regression models. Results for each factor were adjusted for the other factors under consideration.

Setting:

The European Prospective Investigation into Cancer and Nutrition, Oxford cohort (EPIC–Oxford), UK.

Participants:

In total, 20,630 men and women aged 22–97 years at recruitment. Thirty per cent of the subjects were vegetarians or vegans.

Results:

Women had fewer bowel movements on average than men, and were less likely to have daily bowel movements. Mean bowel movement frequency was higher in vegetarians (10.5 in men, 9.1 in women) and especially in vegans (11.6 in men, 10.5 in women) compared with participants who ate meat (9.5 in men, 8.2 in women). There were also significant positive associations between bowel movement frequency and body mass index (BMI), intakes of dietary fibre and non-alcoholic fluids, for both men and women. Vigorous exercise was positively associated with bowel movement frequency in women although results for men were less clear. Alcohol intake was positively associated with bowel movement frequency in men but not in women.

Conclusion:

Being vegetarian and especially vegan is strongly associated with a higher frequency of bowel movements. Moreover, having a high intake of dietary fibre and fluids and a high BMI are associated with an increase in frequency of bowel movements.
The role of values in educational research: the case for reflexivity
Authors: Greenbank Paul
Published: January 2004

Abstract This article explores the meanings involved in the development and implementation of learning and teaching policies in higher education through a single institution case study in an English university. It draws on interview data collected from middle manager‐academics, located in Schools, who are charged with implementing learning and teaching policies. Tensions and contradictions of practice emerged from a detailed analysis of the data identified through three closely related themes: centre/periphery, time and temporality, and disciplinary locations. The central theme, which frames the discussion of the other two, concerns relations between centre and periphery. The manager‐academics identify themselves with the interests of their colleagues within Schools and use their position to mediate between central pressures and practice on the ground. Rather than identifying with managerialist practices, they rely on projected ideals of collegiality in their relationships with School colleagues. At the core of these experiences are differing conceptions of time in the centre/periphery relationship. Different experiences of temporality, tempo, and timing are explored from the manager‐academics' perspective. There is considerable tension between time understood on the ground and the time‐scales of central learning and teaching initiatives. The final theme concerns the organising role of disciplinary identities in articulating meaning at the periphery. Innovations appear rooted in disciplinary practice and some tensions exist between these and perceptions of educational theory and development. The article suggests that these contradictions and tensions might be a source of strength to the institution rather than having negative effects. It concludes with some reflections on the importance of time to the development of educational theory.
School as imagined community in discursive space: a perspective on the school effectiveness debate
Authors: Stables Andrew
Published: January 2004

Abstract A school, like a nation, is a complex system existing in discursive rather than physical geographical space (other than as a set of buildings). The meaning of ‘school’ is therefore dependent on actors' perceptions, and these are dependent on factors apparently beyond the school. Research evidence relating to such perceptions comes not as data or phenomena, in the sense of observable behaviour subject to mathematical laws, but rather as phenomenographic fragments: pieces of described experience. Although numbers can be included in such descriptions, they are thus used qualitatively. Overall evaluative judgements about school (‘good school’; ‘effective school’) cannot validly be derived from statistical models, however sophisticated, as quantitative data alone cannot capture the indefinable range of experiences relating to any particular school, particularly given a lack of absolute consensus about educational values. Research into the effectiveness of schools can thus have limited predictive validity, although reductionist approaches can certainly reveal strong specific correlations that it is tempting to regard as causes and effects, and that might be seen to endure over a period. From this perspective, given the lack of a firm evidence base, policy‐makers with only a researcher's interest in any institution are less well placed to make decisions about particular schools than those ‘on the ground’ with more sophisticated (though still inevitably incomplete) understandings of local complexity. What is important about a school is how it is imagined by those who imagine it, among whom the policy‐makers are inevitably a tiny constituency with very limited terms of engagement. Thus, the methodological argument becomes a political argument for decentralisation.
The national literacy strategy: a critical review of empirical evidence
Authors: Wyse Dominic
Published: January 2004

AbstractThis article examines three areas that are of central importance to the pedagogy of the National Literacy Strategy Framework for Teaching (FFT) at primary level: inspection evidence; school effectiveness (SE) research; and child development evidence. Analysis of national inspection reports on the teaching of English illustrates that these cannot be used as a reliable source of evidence. A focus on the claims made in support of an objective‐based framework in SE research shows that there is very little evidence to support the particular use of objectives in the FFT. A synthesis of child development research in relation to language and literacy finds that the FFT does not adequately reflect the evidence. It is concluded that there is an urgent need for a formal review of the FFT.
Not the whole story of the national literacy strategy: a response to Dominic Wyse
Authors: Beard Roger
Published: January 2004

Abstract There is evidence that the National Literacy Strategy (NLS) has led to a sustained increase in literacy attainment, especially in reading, although recent international comparisons also suggest some additional issues regarding pupil performance in England. The relative success of the NLS may at least partly lie in the policy application of several complementary areas of educational research, a suggestion disputed by Dominic Wyse (this issue). However, his critical commentary is marred by important omissions, particularly of reference to debates about the teaching of reading and to the statutory status of the National Curriculum for English. His alternative suggestions on the use of ‘child development’ evidence lack methodological detail and are only partly formulated.
The Chimpanzees’ Tea Party: A New Metaphor for Project Managers
Authors: Drummond Helga , Hodgson Julia
Published: January 2004

This paper addresses the problem of information technology systems failure. It is argued that conventional approaches to project management assume that success depends upon imposing control. This paper invokes a novel metaphor, namely the chimpanzees’ tea party, for highlighting the limits of this assumption and showing how control-based approaches to project management can be counterproductive. Paradoxically, situations may arise where projects can be more effectively controlled by not attempting to impose control.

Mind is the forerunner of everything. Mind is sovereign. All things are generated by mind.

(Dhamnapadi, verse 1)
Strategic Alignment and Enterprise Systems Implementation: The Case of Metalco
Authors: Grant Gerald G.
Published: January 2004

This paper explores the issue of strategic alignment and enterprise systems (ES) implementation from the point of view of one organization involved in deploying an enterprise resource planning system globally. Two questions motivated this research. First, given that strategic information systems (IS) alignment is viewed as essential to organizational success in deriving value from information technology (IT) investments, what is the experience of organizations in practice in aligning their IT strategies with their business strategies? Second, what is the impact of global ES deployments on strategic IS alignment? Based on an in-depth case study of one organization's experience, the research shows that achieving alignment is still important yet difficult to attain. The pressure for alignment may be even more intense with the deployment of global enterprise-wide systems. The study provides additional empirical support for the strategic IS alignment construct and goes further to suggest that deploying an ES does not by itself create integrated and seamless operating environments. In addition, such an outcome requires significant organizational change at all levels.
Service Provision in a Software Technology Unit
Authors: Mathiassen Lars , Andersson Ingegerd , Hanson Kerstin
Published: January 2004

Large software organizations establish software technology units for managing the methods and tools aimed at supporting their software engineers. This division between software development and new technologies for software development establishes specialized competencies, supports standardization across software projects and departments and provides dedicated resources for innovation. However, such software technology units are faced with complex diffusion projects that are difficult and challenging to manage and that in many cases lead to unsatisfactory results. This paper reports from attempts to improve diffusion practices within a technology unit in a large software organization. Two complementary roles for software technology units, i.e. technology supplier and service provider, are presented and used for interpreting the experiences. The research suggests that technology units in large software organizations can improve their diffusion practices by complementing the traditional role as a technology supplier with that of a service provider. The paper offers lessons on how software organizations can take steps in that direction.
Obituary
Authors: Sauer Chris , Willcocks Leslie
Published: January 2004

It is with regret that we record the death after illness of Dr John Jenkins (died February 2003). John was a reader in computer science at Middlesex University having previously been on the faculties of Ciyu University and Imperial College, London. He was a long-term member of the Journal of Information Technology's international advisory board and is particularly remembered for his support for the Journal of Information Technology in its early years before it had become established as a major international journal. He will be missed.
The Information Technology Outsourcing Risk: A Transaction Cost and Agency Theory-Based Perspective
Authors: Bahli Bouchaib , Rivard Suzanne
Published: January 2004

Many firms have adopted outsourcing in recent years as a means of governing their information technology (IT) operations. While outsourcing is associated with significant benefits, it can also be a risky endeavour. This paper proposes a scenario-based conceptualization of the IT outsourcing risk, wherein risk is defined as a quadruplet comprising a scenario, the likelihood of that scenario, its consequences and the risk mitigation mechanisms that can attenuate or help avoid the occurrence of a scenario. This definition draws on and extends a risk assessment framework that is widely used in engineering. The proposed conceptualization of risk is then applied to the specific context of IT outsourcing using previous research on IT outsourcing as well as transaction cost and agency theory as a point of departure.
New politics, new livelihoods: agrarian change in Zimbabwe
Authors: Chaumbra Joseph , Scones Ian , Wolmer William
Published: January 2004

In the last four years Zimbabwe has featured prominently in headlines around the world. An ongoing radical land reform involving the seizure of largely white-owned commercial farmland has dramatically altered the physical landscape. Alongside this, a new political terrain has rapidly unfolded with new actors and new institutions. Tensions between authoritarian nationalism and ethnic politics, between a militarised, modernist order and ‘traditional’ religion and authority have created a complex political mosaic, made up of multiple and overlapping identities and positions. This is a confusing and dynamic landscape populated by actors as diverse as entrepreneurial war veteran ‘security guards’-cum-cum-protection protection racketeers, militant ZANU(PF) youth brigades, and marauding elephants possessed by chiefly spirits. Focusing on the farm occupations and ‘fast-track’ land reform around Sangwe communal area in Chiredzi district, southeastern Zimbabwe, this paper attempts to make sense of this seemingly chaotic landscape. It explores the new patterns of social differentiation and the emerging lines of political authority, and investigates the impact of these changing circumstances on people's livelihoods.