To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The functional properties of the high-temperature superconductor Y1Ba2Cu3O7−δ (Y-123) are closely correlated to the exact stoichiometry and oxygen content. Exceeding the critical value of 1 oxygen vacancy for every five unit cells (δ>0.2, which translates to a 1.5 at% deviation from the nominal oxygen stoichiometry of Y7.7Ba15.3Cu23O54−δ) is sufficient to alter the superconducting properties. Stoichiometry at the nanometer scale, particularly of oxygen and other lighter elements, is extremely difficult to quantify in complex functional ceramics by most currently available analytical techniques. The present study is an analysis and optimization of the experimental conditions required to quantify the local nanoscale stoichiometry of single crystal yttrium barium copper oxide (YBCO) samples in three dimensions by atom probe tomography (APT). APT analysis required systematic exploration of a wide range of data acquisition and processing conditions to calibrate the measurements. Laser pulse energy, ion identification, and the choice of range widths were all found to influence composition measurements. The final composition obtained from melt-grown crystals with optimized superconducting properties was Y7.9Ba10.4Cu24.4O57.2.
Two broad aims drive weed science research: improved management and improved
understanding of weed biology and ecology. In recent years, agricultural
weed research addressing these two aims has effectively split into separate
subdisciplines despite repeated calls for greater integration. Although some
excellent work is being done, agricultural weed research has developed a
very high level of repetitiveness, a preponderance of purely descriptive
studies, and has failed to clearly articulate novel hypotheses linked to
established bodies of ecological and evolutionary theory. In contrast,
invasive plant research attracts a diverse cadre of nonweed scientists using
invasions to explore broader and more integrated biological questions
grounded in theory. We propose that although studies focused on weed
management remain vitally important, agricultural weed research would
benefit from deeper theoretical justification, a broader vision, and
increased collaboration across diverse disciplines. To initiate change in
this direction, we call for more emphasis on interdisciplinary training for
weed scientists, and for focused workshops and working groups to develop
specific areas of research and promote interactions among weed scientists
and with the wider scientific community.
Bismuth selenide (BixSey) films are deposited onto glass substrate using chemical bath deposition at room temperature. The reacting bath contained bismuth nitrate, triethanolamine and sodium selenosulfate as selenium (Se) source. Ammonium hydroxide is used to adjust the pH of the bath. The films deposited in solutions containing Se source solution of 10 ml and 15 ml are characterized by surface morphological, compositional and structural, properties. The optimum deposition time is about 3 hours for both solutions. Films deposited up to 24 hours in bath with 10 ml Se source solution had thickness ranging up to 232 nm. The deposition rate is found to increase up to 61 nm/h for 3-hour deposition. In the case of bath with 15 ml Se source solution, the film thickness ranged from 45 nm to 632 nm for 1-hour to 24-hour deposition, respectively; with a deposition rate increasing up to 123 nm/h for 3-hour deposition. Film roughness of about 6.6 nm to 22.8 nm is measured by atomic force microscope for films deposited in bath containing 10 mL Se source and 15 ml of Se source, respectively. Crack free layers are observed with randomly large plate-like particles on top of the layer for some films. The films with typical composition of Bi21.8Se78.2 are found to be rich in Se when deposited for 6 hours, whereas the composition of a film deposited in the same bath (10 mL Se source) for 3 hours is found at Bi60.3Se39.6. Additionally, structural analysis performed by x-ray diffraction (XRD) did not reveal well-defined XRD patterns, which indicates that BixSey films were constituted mostly of nanocrystalline grains.
To characterise balance disorders occurring after head trauma, using videonystagmography, and to test the efficiency of videonystagmography as a diagnostic and monitoring tool.
Prospective, cohort analysis of 126 head trauma patients managed with vestibular evaluation, monitoring and treatment, in a tertiary referral centre. Analytical parameters included: head injury severity; balance disorder type, severity and time of onset; and patient recovery and outcome.
Head trauma was minor in 31.7 per cent, mild in 36.6 per cent, moderate in 19 per cent and severe in 12.7 per cent. Balance disorder symptoms included vertigo in 42.9 per cent, unsteadiness in 15.9 per cent, dizziness in 9.5 per cent and none in 31.7 per cent. Videonystagmographic balance disorder diagnosis type was peripheral vestibular in 23.8 per cent, central in 7.9 per cent, mixed in 12.7 per cent, benign paroxysmal positional vertigo in 4.8 per cent and no findings in 50.8 per cent. Balance disorder was immediate in 47.6 per cent (this included all moderate and severe trauma cases). Benign paroxysmal positional vertigo developed within the first week in two-thirds of cases. More severe trauma cases had longer recovery times. Peripheral, mixed and central balance disorders recovered within the first three months. Early rehabilitation of acute balance disorders led to early recovery regardless of diagnosis.
Videonystagmography enables precise, simple, cost-effective monitoring of balance disorders after head trauma, and improves care and outcomes.
This article reviews the literature of multimedia glosses in computer assisted language learning (CALL) and their effects on L2 vocabulary acquisition during the past seventeen years. Several studies have touched on this area to examine the potential of multimedia in a CALL environment in aiding L2 vocabulary acquisition. In this review, the researchers investigate the studies that deal with different modes of multimedia annotations in a CALL environment. This article reviews the empirical studies of multimedia glosses in reading as well as in listening comprehension activities and discusses the factors under which these studies have been conducted and their impact on L2 vocabulary acquisition. The study aims to understand how multimedia glosses have been used in the past to support second language vocabulary acquisition and also to explore any evidence regarding how multimedia glosses in a CALL environment can enhance the acquisition of L2 vocabulary. Only empirical studies (18 studies published in international refereed journals and conference) have been reviewed exclusively. The article discusses the findings of the reviewed studies and recommends future research.
6H- and 4H- SiC crystals grown on the Si-face were chemically etched on the as-grown (virgin) surface and the C-face (sliced side). The etching of both the surfaces revealed a strong relationship between a variety of etch pits and the morphological features of the grown boule surface. Several types of etched patterns were revealed. On the Si face, we observed small, medium, and large hexagonal shaped pits and a linear array of small etch pits. However, the C face contained only small pits and a linear array of small pits.
We observed individual or group of dislocations that were connected from the Si face to the opposite C face of the wafer. Also, etch pit lines oriented along specific crystallographic directions were seen.
Our experimental observations have provided a physical basis to explain the generation of defects in SiC. An analysis of our observations show that a correlation exists between the distribution of different size etch pits and the condition of the crystal growth process.
Dilute HF/RCA and IEMC/SC2 cleans have been evaluated on two process lines
with different metallic contamination levels. VPD-DSE-TXRF and SPV
techniques were used to monitor the metallic contamination. Gate oxide
integrity(GOI) tests were performed on several structures. Both HF/RCA and
IMEC/SC2 cleans have shown good Qbd and Ebd results for the clean process
line. Lower Qbd and Ebd values were obtained for both cleans in the
relatively contaminated process line. These results suggest that poor GOI is
related to the metallic contamination in the oxide or at the
Comparative studies on the effect of Ultra-dilute RCA cleans,
chemical ratios in excess of 300:1, and Dilute RCA cleans,
chemical ratios around 50:1, on the integrity of thin gate oxides have been
performed. Ultra-dilute RCA chemistries have shown particle removal
efficiency, metallic contamination removal, surface roughness, Qbd, BVox and
defect density equivalent to those obtained using dilute RCA chemistries.
Furthermore ultra-dilute chemistries use less chemical leading to shorter
rinse times and thus increased throughput as compared to the dilute RCA
Basic recent results, properties and characteristics of ionic polymer conductor nano-composites (IPCNC) as biomimetic distributed nanosensors, nanoactuators and artificial muscles are briefly discussed in this paper. Some fundamental considerations on biomimetic distributed nanosensing and nanoactuation are first presented and then expanded to cover some recent advances in manufacturing techniques, force optimization, 3-D fabrication of IPMC's, recent modeling and simulations, sensing and transduction and product development. This paper also covers some recent industrial and medical applications including a multi-fingered grippers (macro, micro, nano), biomimetic robotic fish and caudal fin actuators, diaphragm micropump, multi-string musical instruments, linear actuators made with IPMNC's, IPMNC-based data glove and attire, IPMNC-based heart compression/assist devices and systems, wing flapping flying system made with IPMNC's and a host of others.
A new species of calanoid copepod, Centropages uedai sp. nov., is described from the neritic waters of the northern Red Sea. This species is characterized by: (1) symmetry of a globular female genital double-somite that is ornamented with an anterior irregular group of spinules as well as transverse and dorsolateral rows of spinules on each side; (2) second exopodal segment of female leg 5 bearing a strong trough medial process serrated along the distal 4/5 of its posterior margin; (3) second exopodal segment of male right leg 5 serrated laterally along distal 1/5 of its medial process; (4) third exopodal segment of male right leg 5 with medial seta bifurcated at its tip and with hyaline ridge on both sides; and (5) second exopodal segment of male right leg 4 asymmetrical with undulating, thicker and longer lateral spine than left leg. The new species does not belong to any known species groups of the genus.
A new species of calanoid copepod, Centropages aegypticus sp. nov. collected from the Egyptian coasts of the northern Red Sea is described. This species is unique in having two pointed conical processes on the dorsal surface of cephalosome in both sexes, female genital compound somite with irregular-surface outline of the right swelling part and transverse dorsolateral row of spinules on the left side, 2-segmented exopod of the female leg 5, asymmetrical medial processes of the female leg 5, of which the left one is longer and medially-curved and the right one with oblique row of thick spinules, and a club-shaped medial seta on the third exopodal segment of the male leg 5. The new species is similar to C. tenuiremis, but is not assigned to the same species group as the latter species or to any other groups.
In order to establish firm evidence for the health effects of dietary polyphenol consumption, it is essential to have quantitative information regarding their dietary intake. The usefulness of the current methods, which rely mainly on the assessment of polyphenol intake using food records and food composition tables, is limited as they fail to assess total intake accurately. This review highlights the problems associated with such methods with regard to polyphenol-intake predictions. We suggest that the development of biological biomarkers, measured in both blood and urine, are essential for making accurate estimates of polyphenol intake. However, the relationship between dietary intakes and nutritional biomarkers are often highly complex. This review identifies the criteria that must be considered in the development of such biomarkers. In addition, we provide an assessment of the limited number of potential biomarkers of polyphenol intake currently available.
Whole soybean (SB) is used as a high energy-protein supplement for dairy cows, but the protein is highly degradable by rumen microbes. Various chemical and physical processing has been suggested to decrease ruminal protein degradability, that heat processing is the most commonly used physical method. Modern systems for protein evaluations in ruminants are moving in the direction of predicting absorption of amino acids from the small intestine, so the determination of intestinal digestibility of amino acids is of special importance particularly in heat-treated feedstuffs. The objective of this research was to elucidate the effects of roasting and steep-roasting on ruminal and post-ruminal disappearance of essential and non-essential amino acids (EAA and NEAA) of Iranian SB.
Myobacterium malmoense is a non-tuberculous mycobacterium that most commonly causes pulmonary infection, particularly in patients with underlying pulmonary disease or immunodeficiency. We describe a case of Mycobacterium malmoense infection of the larynx in a previously well middle-aged woman, which has previously not been reported. The case highlights the importance of considering atypical mycobacterial infection in the differential diagnosis of laryngeal lesions.
Fifteen patients requiring palliation for tetralogy of Fallot were treated by balloon dilation because of hypercyanotic spells. The mean age at dilation was 1.9 ± 0.7 years (range 0.5 – 3), and the mean weight 9.8 ± 2.1kg (range 6.0 –13.5). Dilation of the outflow tract was combined with dilation of the left and/or right pulmonary arteries in 5 patients. Successful dilation was achieved in 12 patients (80%), but failed in 3 patients with hypoplastic pulmonary arteries. In one patient, the stenosis of the right pulmonary artery could not be dilated because of a very sharp angle at the site of the stenosis. Two of the 3 patients in whom the procedure failed died of severe cyanotic spells within 24 hours of the unsuccessful procedure. No major complications occurred during or after the procedure in the cases undergoing successful dilation. The arterial oxygen saturation increased significantly, from 71 ± 5.7% to 89 ± 3.9%, immediately after the procedure (p < 0.005). During a period of follow up of 6 ± 3.7 months (range 1 – 13), the procedure was repeated on 3 occasions, and successfully accomplished in 2 of these. In conclusion, balloon dilation is a satisfactory palliative procedure for tetralogy of Fallot in those units in which total correction is not performed under 2 to 3 years of age.