bluuebunny/crossref_metadata_2025 huggingface dataset:
Guidewire assisted cephalic vein cutdown for insertion of totally implantable access ports
Authors: Chang H.M. , Hsieh H.F. , Hsu S.D. , Liao G.S. , Lin C.H. , Hsieh C.B. , Yu J.C.
Published: February 2007

Background

Totally implantable access ports (TIAP) placed by the cephalic vein cutdown technique have high failure rates.

Methods

We describe a guidewire assisted technique of the cephalic vein cutdown for TIAP placement that can be easily introduced catheter when difficulties in insertion of the catheter. The key point of the presented technique is the use of J guidewire to go beyond the stenosis and advancement of catheter through the guidewire into the superior vena cava.

Results

We used this technique for introducing the catheter in six patients without failure or complication.

Conclusion

The presented technique is easy and simple. It can be used where there are difficulties in insertion of the catheter by cephalic vein cutdown method. J. Surg. Oncol. 2007;95:156–157. © 2007 Wiley‐Liss, Inc.
Was ist neu?
Authors: Kock Holger , Thoß Andreas
Published: February 2007

Liebe Leserin, lieber Leser,

was ist neu? – Genau diese Frage stand beim Zusammenstellen der Inhalte fürs neue Laser Technik Journal im Mittelpunkt. Denn wir wollen der Laserbranche nicht nur einfach eine neue Zeitschrift präsentieren, sondern vielmehr auch inhaltlich mit Neuem überzeugen. Was für uns neu ist? Lesen Sie selbst!

Neu ist, … was die Zukunft bringt.

Arnold Mayer analysiert für Sie den Lasermarkt in der Materialbearbeitung und sieht bis zum Jahr 2010 gute Wachstumsperspektiven – mit jährlichen Zuwachsraten im zweistelligen Bereich! Mehr dazu auf Seite 9.

Neu ist, … was Entscheider denken.

Menschen sind die treibende Kraft. Lesen Sie ab Seite 13, was Dirk Basting, der ehemalige Vorstandsvorsitzende von Lambda Physik, zu neuen Märkten und neuen Projekten zu sagen hat.

Neu ist, … was neu gesehen wird.

Das Laser Technik Journal beleuchtet Schwerpunktthemen aus verschiedenen Blickwinkeln. Das aktuelle Spezial “Lasermaterialbearbeitung” befasst sich mit Strahlquellen und Anwendungen im industriellen Einsatz – mehr dazu ab Seite 40.

Neu ist, … was Bewährtes ablöst.

In engen Märkten wächst die Bedeutung von gutem Qualitätsmanagement. Wie wichtig optimierte Prozesse für effiziente Abläufe sind, lesen Sie auf Seite 35.

Neu ist, … was man noch nicht weiß.

Aktuelle Produkte, Nachrichten zu Firmen und Personen sowie Veranstaltungstipps halten Sie auf dem Laufenden.

Viel Spaß beim Lesen wünscht Ihnen die Redaktion
Laser in der Materialbearbeitung – Eine Marktübersicht
Authors: Mayer Arnold
Published: February 2007

Seit dem Spitzenjahr 2000 ist die Nachfrage für Lasersysteme zur Materialbearbeitung rückläufig. Prognosen für die nächsten Jahre setzen nicht nur auf eine konjunkturelle Erholung, sondern vor allem auf eine stärkere Marktdurchdringung und neue Anwendungen der Lasertechnologie. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Selective Enzymatic Grafting by Steric Control
Authors: Duxbury Christopher J. , Cummins David , Heise Andreas
Published: February 2007

Enzymatic grafting of caprolactone was carried out from poly[styrene‐co‐(4‐vinylbenzyl alcohol)] containing 10% hydroxyl functional monomer and compared with the grafting of vinyl acetate. A molecular weight increase due to the grafting of polycaprolactone was observed by size exclusion chromatography. Closer investigation of the grafting density by 1H NMR revealed an upper limit to the amount of grafting of about 50–60% of the pendant hydroxyl groups leaving unreacted hydroxyl groups on the polymer backbone available for subsequent reactions. The higher grafting density (95%) obtained with vinyl acetate suggests that this is not due to limited accessibility of the backbone but sterical constrains. Moreover, the grafting action of polycaprolactone seems to be a combination of grafting from by monomer initiation and grafting onto by transesterification of polycaprolactone.

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Synthesis of Ferrocene‐Branched Chitosan Derivatives: Redox Polysaccharides and their Application to Reagentless Enzyme‐Based Biosensors
Authors: Yang Weiwei , Zhou Hong , Sun Changqing
Published: February 2007

Ferrocene‐branched chitosan derivatives (CHIT‐Fc) are synthesized by reductive N‐alkylation of chitosan with ferrocenecarboxaldehyde. The structures of the products are determined by 1H NMR and FT‐IR spectra. CHIT‐Fc is used as a functionalized matrix to immobilize GOD on glassy carbon electrodes. Ferrocenyls in CHIT‐Fc exhibit an excellent redox activity and establish efficient electrical communication between GOD and the electrodes for the oxidation of glucose. The development of a reagentless glucose biosensor is described.

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Fatty acids in tea shoots (Camellia sinensis (L.) O. Kuntze) and their effects on the growth of retinal RF/6A endothelial cell lines
Authors: Shen Sheng‐rong , Yu Hai‐ning , Chen Ping , Yin Jun‐jie , Xiong Yao‐kang
Published: February 2007

Chemo‐protective effects of tea on ocular diseases were recorded in Chinese pharmacopoeia about 2000 years ago by eating tea. In the present study, contents of fatty acids (FAs) in tea shoots were determined by capillary GC; and the growth of RF/6A cells was also investigated by exposure to various representative FAs existing in tea shoots with pathologically relevant concentrations (40–500 μM) by ameliorated MTT assay and flow cytometry. Electron spin resonance (ESR) was used to measure oxygen consumption and investigate the free radical scavenging ability of linoleic acid (LA). Results showed that the most abundant long chain FAs were palmitic, linoleic, and α‐linolenic acid in tea shoots; some RF/6A cells became suspended in culture medium treated by a high dose of both saturated and unsaturated FAs, but no apoptosis was observed. Moreover, it seemed that those FAs with different structure had various effects on the cell proliferation at their relatively low concentrations, LA expressed antioxidant activity in this study, which might be an important mechanism on the protection of eyes.
Theoretical study of the gas‐phase elimination kinetics of several heterocyclic carbamates
Authors: Graterol Mariana , Cordova Tania , Chuchani G.
Published: February 2007

The homogeneous, unimolecular, gas‐phase elimination kinetics of several heterocyclic carbamates was studied at the MP2/6‐31G level of theory under the average experimental conditions for each substrate. The elimination products for these carbamates are the corresponding carbamic acid and isobutylene. The intermediate acids are unstable and decarboxylate at the reaction temperature. Calculated thermodynamic and kinetic parameters are in good agreement with the experimental values, displaying the same reactivity order observed experimentally. An increase in the electron‐withdrawing effect of the substituent on the carbamate nitrogen, increases the elimination rate. Transition state structures are described as six‐membered rings with some departure from planarity. NBO charge analysis reveals strong polarization at the O(ester) δ−Cδ+ bond. Bond indexes and synchronicity parameters are consistent with a concerted polar type of mechanism with O(ester) δ−Cδ+ bond breaking as the most important process. Copyright © 2007 John Wiley & Sons, Ltd.
Substituent effects on ion complexation of para‐tert‐butylcalix[4]arene esters
Authors: Lazzarotto Márcio , Francisco Marjarie Marrie , Nachtigall Francine Furtado , Lazzarotto Marcelo
Published: February 2007

Phenoxy‐carboxy‐methoxy‐p‐tert‐butylcalix[4]arene esters were synthesized in order to evaluate the role of electronic parameters on the complexation of alkaline metal cations. Extraction constants of metal picrates to organic phase were determined. Plots of log (KR/KH) against Hammett σ and σ gave good linear correlations. The best correlations with σ were obtained for K+ and Rb+, while the best correlations with σ were obtained for Li+ and Na+. All Hammett plots gave a straight descending line, which is consistent with a dependence of the electronic density on the CO. Treatment of data using the Yukawa–Tsuno equation revealed a variation in the contribution of resonance in the complexation of alkaline metal ions, which is maximum for Na+ and minimum for Rb+. Electronic parameters were calculated for a related acyclic model structure and only the HOMO energy showed a good correlation with log (KR/KH). Copyright © 2007 John Wiley & Sons, Ltd.
Overexpression of cyclooxygenase‐2 in human prostate carcinoma and prostatic intraepithelial neoplasia‐association with increased expression of polo‐like kinase‐1
Authors: Denkert Carsten , Thoma Andrea , Niesporek Silvia , Weichert Wilko , Koch Ines , Noske Aurelia , Schicktanz Hanka , Burkhardt Mick , Jung Klaus , Dietel Manfred , Kristiansen Glen
Published: February 2007

BACKGROUND

Cyclooxygenases (COX) as well as Polo‐like kinases (PLK) are involved in proliferation and cell cycle regulation and have been suggested for preventive and therapeutic approaches in prostate carcinoma.

METHODS

In this study, we studied expression and prognostic impact of COX‐2 in invasive prostate carcinoma, prostatic intraepithelial neoplasia (PIN), atrophic glands, and normal prostatic glands, and investigated the association between COX‐2 and PLK‐1.

RESULTS

We observed a positivity for COX‐2 in 72.1% of PIN and in 44.7% of prostate carcinomas with an overexpression of COX‐2 in prostate cancer and PIN compared to benign prostatic tissue (P < 0.0005). Furthermore, we observed a strong correlation between expression of PLK‐1 and COX‐2 (P < 0.0005).

CONCLUSIONS

To our knowledge, this is the first report of a correlation between COX‐2 and PLK‐1 in a malignant tumor. COX‐2 and PLK‐1 may be interesting targets for new molecular therapies in prostate cancer. Prostate 67: 361–369, 2007. © 2007 Wiley‐Liss, Inc.
Antiinflammatory effect of topically applied propolis extract in carrageenan‐induced rat hind paw edema
Authors: Naito Yukiko , Yasumuro Misao , Kondou Keiichiro , Ohara Naoki
Published: February 2007

The antiinflammatory effect of an ointment containing propolis extract (3%–7%) was examined using carrageenan‐induced hind paw edema in rats. Treatment with the ointment inhibited the edema moderately, and the inhibition was significant at 5% and 7%. Additionally, the effect of the ointment on chemotaxis of human polymorphonuclear leukocytes (PMNs) was investigated using the agarose plate method. Migration of PMNs toward zymosan‐treated serum was inhibited in the presence of 5% propolis ointment. These results demonstrate that topical application of propolis extract is effective in inhibiting carrageenan‐induced rat hind paw edema, and its inhibitory effect on the chemotaxis of PMNs may also contribute to the antiinflammatory effect. Copyright © 2007 John Wiley & Sons, Ltd.
Meteorology of Nigeria and adjacent territory
Authors: Hamilton R. A. , Archbold J. W. , Douglas C. K. M.
Published: February 2007

This paper deals with the general meteorology of Nigeria and adjacent territory. Part I describes the air masses and prevailing winds and the characteristic weather of four weather zones. Part II describes dust haze and just storms which occur and discusses the question of forecasting the onset and clearance of dust haze. Part III deals with instability phenomena in the form disturbance lines and local thunderstorms; a theory of their mechanism is put forward which agrees well with observed phenomena.
Convection in the atmosphere near the ground
Authors: Sutton O. G.
Published: February 2007

The details of the processes by which heat is transported through the lower atmosphere are, for the most part, still obscure although our knowledge of typical temperature distributions near the ground is now well founded, thanks chiefly to the researches of Johnson (1929), Best (1935), Flower (1936) and Johnson and Heywood (1938). These investigations establish in considerable detail the principal features of the mean temperature field from 2·5 cm. to 87 m., so that the data for the elucidation of the problems of heat transfer are undeniably available, but the complexity of the situation, depending as it must upon the joint effects of radiation, conduction and convection, is such that there is little hope that a comprehensive mathematical theory will be evolved for some time yet.

The present paper is an attempt to clarify certain aspects of the problem, and in particular to analyse the general nature of the flux of heat through the lower atmosphere on a clear day in summer. The conclusion is reached that to explain the type of heat flow which prevails in these conditions necessitates the consideration of the nature of the vertical currents due to buoyancy and their effect on the virtual coefficient of conduction, and for this purpose a theoretical treatment is proposed which differs in many ways from those previously advanced.
The dissipation of scattered and broken cloud
Authors: Hewson E. Wendell
Published: February 2007

Shaw's early work on the dissipation of scattered and broken cloud is outlined and the loss of heat by cloud resulting from terrestrial radiation is indicated. The process of cloud dissipation is described and various criteria are given.

The implications of these concepts in evaluating the significance of the slice method for studying cumulus clouds are then considered.

A method of calculating the time required for a specified system of scattered and broken cloud to dissipate as a result of radiational cooling is described and the assumptions involved are discussed. The influence of the turbulent transfer of heat and water vapour under various conditions is indicated in a general manner and the effect of the absorption of solar radiation by the cloud is evaluated.

Widespread vertical motion of the atmosphere may have a marked influence on cloud dissipation, depending on whether ascent or subsidence of the whole air mass is occurring. A method of calculating the amount of subsidence required to cause a given system of cloud to dissipate is described. For a particular case, the effects of ascent of the air mass and of radiation are combined, and useful criteria thereby obtained.
Equatorial circulations
Authors: Sellick N. P.
Published: February 2007

Grimes (1937) made a first essay to treat the passage of air across the equator dynamically. His work has been extended by Crossley (1948). In the present paper a flow pattern is presented which proves not intractable in spherical polar co‐ordinates in the equatorial belt. Frictionless horizontal flow is considered and it is shown that clockwise and counter‐clockwise circulations can exist in equilibrium on the equator. The centre of the pressure field is displaced into the hemisphere for which the circulation is cyclonic and both circulations thus appear as cyclones. It is found that trajectories and contours pass freely across the equator but that the relation between winds and contours is variable.
Empirical formulae for the terminal velocity of water drops falling through the atmosphere
Authors: Best A. C.
Published: February 2007

From a consideration of experimental measurements of the terminal velocity of water drops and of the drag coefficient of rigid spheres it is suggested that a formula of the type V = A exp bz { 1 – exp [– (d/a)n]} may be used to represent the terminal velocity of water drops which are larger than those to which Stokes's law is applicable and which are falling through a standard atmosphere. If V (the terminal velocity) is measured in cm/sec, z (the height) in km and d (the drop diameter) in mm the values of the constants are as follows:— I.C.A.N. atmosphere Summer tropical atmosphere Range of d mm A b a n A b a n 0.3 to 6.0 932 0.0405 1.77 1.147 958 0.0354 1.77 1.147 0.05 to 0.3 191 0.0290 0.316 1.754 188 0.0256 0.304 1.819 If the drops have diameter less than 0.05 mm, Stokes's law is applicable and V = A d2 exp bz where A is 3040 and 2840 in the I.C.A.N. and S.T. atmospheres respectively and b has the values 0.0191 and 0.0172 in these two atmospheres.
The ratio between observed velocities of the wind at 50 feet and 2000 feet over the North Atlantic Ocean
Authors: Gordon A. H.
Published: February 2007

The ratio of the wind at 50 ft to the wind at 2000 ft has been calculated for a number of cases from ocean weather ship observations over the North Atlantic and mean values classified according to the lapse rate and the velocity of the wind at 2000 ft. Curves have been drawn showing the variation of the ratio v50/v2000 with lapse rate and v2000 respectively.
The quasi‐geostrophic advective wave in a baroclinic zonal current
Authors: Sutcliffe R. C.
Published: February 2007

An idealised advective wave is studied on the assumption of geostrophic advection of temperature. There is a genuine instability of zonal motion due to this factor and the wave form is similar to thermally asymmetrical depressions and anticyclones. The speed of the unstable waves is Ū − Uc/2 rather than the Ū − Uc of barotropic theory (Ū the mean zonal wind, Uc the Rossby westward component due to variation of Coriolis parameter).

Waves become stable when (approximately) the root‐mean‐square zonal thermal wind becomes equal to Uc. This is near the stationary wave length. There are two types of stable waves, the thermally in‐phase and the thermally antiphase waves. The antiphase waves move eastward relative to the surface zonal flow, the in‐phase waves are retrograde.

The wave characteristics depend on the thermal‐wind conditions, the surface zonal wind is simply additive to the wave speed.

The results support the author's development theory. They do not encourage much optimism in the direct application of barotropic concepts to the baroclinic atmosphere.
Billow clouds
Authors: Scorer R. S.
Published: February 2007

The difficulties of deducing a formula for the dimensions or spacing of cloudlets on the assumption that they are convection cells or unstable waves are discussed. The formula

where h is the depth of the statically unstable layer is then deduced for billow clouds of a particular type, on the assumption that they consist of parallel rows of rotating masses of air moving with the mean wind of a shearing layer and sandwiched between stable wave motions above and below.
A technique for wind analysis and forecasting as applied to Victoria, British Columbia
Authors: McIntyre D. P.
Published: February 2007

Through the use of statistics the most frequent wind directions at Victoria are isolated and their causes considered. Charts of the seasonal variation in wind direction are constructed and the causes for these changes discussed. Finally the data are developed to permit quantitative forecasting of the wind direction at Victoria and the probabilities of the accuracy of the forecasts are calculated.
Records of snowfall in Britain
Authors: Ashmore S. E.
Published: February 2007

Different stations do not all record with equal fidelity the number of days on which snow falls. To obtain intercomparability of records, equations are given by which corrections can be applied to records which have missed some of the snowfall.
Condensation nuclei and the development of radiation fog
Authors: Best A. C.
Published: February 2007

The growth of liquid‐water droplets upon condensation nuclei as the relative humidity rises from 80 per cent to 100 per cent is examined. It is assumed that the condensation nuclei consist of sea‐salt particles and that the droplets are always in instantaneous equilibrium with the ambient relative humidity. An arbitrary nucleus‐size distribution formula, which is easily adjusted to fit an intuitively reasonable size distribution, is also assumed. It is found that the shape of the nucleus‐size distribution curve has very little effect upon the computed value of the liquid‐water content W of the fog though at saturation W varies as the square root of the mean mass of the nuclei. In near‐saturation conditions a small variation in relative humidity has a big effect upon W.

A formula for drop‐size distribution in fog at saturation is developed and found to agree with measurements.

Visibility in the developing fog is briefly considered and it is shown that Koschmieder's formula, applied to the growing water drops, leads to results consistent with experience. Neither the mean nucleus mass nor the shape of the nucleus‐size distribution curve affect the visibility at saturation.
A comparison of hemispheric circulations with particular reference to the western Pacific
Authors: Gibbs W. J.
Published: February 2007

Using daily hemispheric synoptic charts for midwinter and midsummer months the distributions of pressure systems in the two hemispheres are compared. From mean pressure charts and charts of ‘mean streamlines,’ meridional cross‐sections of mean zonal wind have been constructed for the western Pacific for the mid‐months of the four seasons. The main features of the circulation in the Australian region are discussed and comparisons are made between the circulations of the hemispheres.
The conditions for dynamical similarity of motions of a frictionless perfect‐gas atmosphere
Authors: Batchelor G. K.
Published: February 2007

The object of this paper is to show, in an elementary way, the general significance of the Richardson number for motions of a frictionless perfect gas of variable density subject to gravity. Dimensionless parameters like the Richardson number are important in relation to the concept of dynamical similarity of flow fields, and as a consequence the paper consists largely of discussions of the conditions for dynamical similarity of flow fields of specified kind. It is established that if the flow fields are such that the pressure and density everywhere depart by small fractional amounts only from the values for an equivalent atmosphere in adiabatic equilibrium and if the vertical length scale of the velocity distribution is small compared with the scale height of the atmosphere, the Richardson number is the sole parameter governing dynamical similarity. Various possible forms of the Richardson number are examined.
Transverse flow at entrance and exit to jet streams
Authors: Murray R. , Daniels Sylvia M.
Published: February 2007

From a statistical examination of wind observations near jet streams, two conclusions are reached:

(a) In the jet‐stream entrance region there is evidence of a component of wind towards the left (looking downstream), and this reaches a maximum at the level of the jet centre and falls off above and below. It is probable that this arises from an ageostrophic flow across the contours as a consequence of the acceleration of the air downstream. The transverse flow would be consistent with the existence of a direct thermal circulation either above or below the jet stream, or both.

(b) In the exit region the cross‐stream wind component is towards the right (looking downstream), and it reaches a maximum at the level of the jet centre and falls off above and below. This probably arises from an ageostrophic motion across the contours as a result of the deceleration of the air downstream. It would be consistent with an indirect thermal circulation either above or below the jet stream, or both.

For a sample of observations over the British Isles, the jet axis in entrance regions is in the mean about 2,000 ft (27 mb) higher than in exit regions.
A photoelectric raindrop spectrometer
Authors: Mason B. J. , Ramanadham R.
Published: February 2007

An instrument which gives a continuous, automatic record of the size distribution of raindrops at ground level is described. The light scattered by the drops in falling through an optically defined area of a light beam is focused on to a photomultiplier cell and the resulting voltage pulses are sorted electronically into eight different size groups. The spectrometer is used to study the variation of the drop‐size spectrum with time and with the rate of rainfall. Calibration curves and some specimen results are presented.
The origin of atmospheric nitrous oxide
Authors: Goody R. M. , Walshaw C. D.
Published: February 2007

New observational data are discussed which indicate that:

(a) Nitrous oxide is uniformly mixed with the atmosphere up to 10 km and perhaps to 40 km, and that the volume mixing ratio is 3.5 × 10−7.

(b) Bacterial reactions in the soil can supply nitrous oxide to the atmosphere at a rate sufficient to compensate photo‐chemical decomposition.

(c) The formation of nitrous oxide by homogeneous chemical reactions is probably of less importance.

(d) The average magnitude of the nitrogen cycle between earth and atmosphere is probably not less than 1011 molecules cm−7 sec−1..
The nature of convection as revealed by soaring birds and dragonflies
Authors: Scorer R. S.
Published: February 2007

Birds and dragonflies can be used as indicators of the extent and intensity of vertical currents, particularly of the nature of convection below cloud base during its period of growth. The bubble theory of Scorer and Ludlam is used to interpret the observations of Hankin in India. The possibility of deriving information from the flight of swallows in Britain is also discussed. In hot sunshine and no wind the air appears to stream steadily upwards from fixed places for the first few metres. The birds indicate that convection develops upwards, the heavier ones which soar at greater heights taking to the air last. The upcurrents are stronger and wider at greater height and drift with the wind; they react more slowly at greater height to changes of sunshine on the ground. When convection is intense the upcurrents appear more sharp‐edged. Puffs of wind are associated with the descent of air from above the superadiabatic layer to replace a part of that layer that is ascending as a newly‐created bubble. When the air is stirred mechanically by wind, bubble formation in the lowest layers is reduced.

It is suggested that air movements on the scale of ordinary convection are an element in the climate as important as any other in the life of many birds.
Dimensionless equations for the growth of a drop of salt solution
Authors: Best A. C.
Published: February 2007

The usual equations for the transfer of heat and water vapour to and from a drop of salt solution in an atmosphere with which the drop is not in equilibrium involve the relative humidity of the atmosphere, the drop size, the mass of the salt nucleus and various physical characteristics of air and water which depend upon temperature. Generally an explicit solution of the equations is not possible and, if more than one set of circumstances are to be considered, considerable labour may be involved in obtaining numerical solutions. The following paragraphs indicate a convenient way of manipulating the equations so that the effects of different temperatures and different salt nucleus masses may be allowed for by means of a simple multiplying factor.
The computation of forecast charts by application of the Sawyer‐Bushby two‐parameter model
Authors: Bushby F. H. , Hinds Mavis K.
Published: February 2007

Two series of 12‐hr and 24‐hr forecast 500 mb, 1,000 mb and 1,000–500 mb thickness charts have been computed electronically using the Sawyer‐Bushby (1953) two‐parameter baroclinic model of the atmosphere. The results are compared with the actual charts, and a good degree of correspondence is found between the actual and computed charts.
Solar radiation and the duration of sunshine
Authors: Black J. N. , Bonython C. W. , Prescott J. A.
Published: February 2007

Records of solar radiation (Q) and of duration of sunshine (n) on a monthly basis have been collected for 32 stations and regression equations relating the data calculated in the form Q = QA (a+bn/N) where QA is the maximum possible radiation in the absence of an atmosphere, and N is the maximum possible duration of bright sunshine. For five of these stations records for long series of individual months have been examined and for all stations mean monthly values. In the overall regression equation a = 0.23 and b = 0.48.
Modification of the size distribution of falling raindrops by coalescence
Authors: Mason B. J. , Ramanadham R.
Published: February 2007

The manner in which the size distribution of raindrops is modified during their fall by mutual coalescence, accretion with cloud droplets, and by evaporation below cloud base is investigated. It is shown that if a constant flux of raindrops having an exponetial size distribution occurs at the level of origin (just below the melting level in a layer‐cloud) to give a steady‐state, this initial distribution will undergo considerable modification after a fall of 1 km, the smaller drops being seriously depleted and the larger ones increased. All three processes will cause a shift in the drop‐size spectrum towards larger diameters and produce an increase in the intensity of the radar echo at lower levels of the kind which is sometimes observed. Because of this modification of the drop‐size spectrum during fall and because of the rather rapid fluctuations which are frequently observed in the distribution at the ground, it is not often possible to correlate the latter with the intensity of the radar echo located higher up.
The distribution of wave heights and periods in ocean waves
Authors: Darlington C. R.
Published: February 2007

Automatic records of deep ocean waves obtained by a British Ocean Weather Ship have been analysed. The results are compared with those of similar analyses made by other writers. Relations between the parameters describing wave heights are shown to be in close agreement with deductions made by Longuet‐Higgins from a theoretical model, over a range of wave heights which includes all but the most exceptional conditions. Wave‐period parameters are also calculated, but relationships between them are not so clearcut as for wave heights.
The electric charge of raindrops
Authors: Smith L. G.
Published: February 2007

The observations which are described and discussed in this paper were obtained using equipment designed to record rapidly, and without ambiguity, the electric charge and size of individual raindrops. The electric charge is measured by electrostatic induction on a metal cylinder as the drop falls through. The size of the smaller drops is determined from the time of fall between two such cylinders, while the size of the larger drops is measured by the change of capacity of a parallel‐plate condenser as the drop passes between the plates. The point‐discharge current, electric‐field strength and rain current were also measured.

The observations show that on all occasions the range of charge on a particular size of drop is large, often including both signs, and that this range is not appreciably reduced by considering drops recorded during shorter time intervals. However, it is often found that the average charge and the limits of the range of charge show definite relations to the size of the drop. The variation of average charge is such that there is a certain size for which the average charge is zero; for smaller drops the average charge is opposite in sign to that of the electric field, while the larger drops have average charges of the same sign as that of the electric field.

On some occasions the charges on the drops are too small to be recorded. The field is then usually reversed to a small negative value. It is suggested that the drops are falling from electrically neutral or slightly electrified clouds, the reversal of the field resulting from the splashing of drops on the ground.

The capture of ions by raindrops falling in the region of the point‐discharge current below an electrified cloud is examined and it is shown that, if reasonable assumptions are made about the initial charges on the drops, the relation between the charge and size of drops arriving at the ground is similar to that found experimentally. Comparison of theory and experiment indicates that the field increased with height owing to the point‐discharge space charge.

The range of charge is attributed to the mixing, while falling, of drops leaving the cloud base in regions of different current density. This requires that the regions of high current density are small areas of the cloud base, probably not exceeding 100 m in diameter.
The influence of variable mixing ratio and temperature on the radiation flux
Authors: Plass G. N. , Fivel D. I.
Published: February 2007

A rapidly convergent solution is obtained for the equations of radiative transfer. An absorbing atmosphere having an arbitrary variation of mixing ratio, temperature and pressure with height is considered. The Lorentz shape of the spectral lines together with the dependence of their line strengths and half‐widths on pressure and temperature are taken into account in the calculations. It is assumed that the lines do not overlap and the range of validity of this approximation is stated. It is shown that the expression for the absorption of radiation over a path between any two heights can be written in a tractable form even after three‐fold integration over the variable conditions along the path, over frequency and over all angles in the hemisphere. When the mass per unit area, along the path, is small or the line intensity is small or both, thus causing the absorption of radiation to be small even at the centre of the line, the integrated absorption is proportional to the dimensionless constant gamma that occurs in atmospheric radiation problems; when these quantities are large, thus causing the absorption to be complete for several half‐widths from the centre of the line, the integrated absorption is proportional to the square‐root of gamma. This is the generalization to variable path conditions of the linear and square‐root relations of infra‐red spectroscopy. Some examples of the method developed here are given when the variable conditions along the atmospheric path can be represented with sufficient accuracy as polynomials. An approximation to the H2O and CO2 distributions shows that the absorption of radiation from the ground at a given height depends greatly on the variation of the mixing ratio with height.
The possibilities of multilayer coatings for auroral research
Authors: Jarrett A. H.
Published: February 2007

Although the examination of the spectra of aurorae provides a method of estimating temperature at auroral levels, the low dispersion of auroral spectrographs hitherto used and the long exposures required lead to uncertain results.

During the past five years it has been established that multilayer coatings are generally more efficient than their silver counterparts for interferometric work. This increase in efficiency is effected by a reduction in the absorption from, for example, 3 per cent for a silver film of 94 per cent reflectivity to 1 per cent for a multilayer coating reflecting 94 per cent of the incident light. Consequently the transparency of a Fabry‐Perot interferometer can be considerably increased by the use of multilayer coatings, so reducing the exposure‐time for recording fringes from an extended source.

Several trials on auroral glows have shown that it is possible to record Fabry‐Perot fringes from the 5577 Å radiation with exposures of as little as 20‐min duration, using simply a multilayer interferometer placed in front of an f/2 camera.

These investigations are being continued with the intention of deriving temperature distributions from measurements of the fringe halfwidths, and line‐of‐sight motions of the aurorae from displacements of the fringes.

Further applications lie in the use of narrow bandwidth (≃ 20 Å at 5500 Å and 60 per cent transmission) all‐dielectric type interference‐filters, particularly for investigating the form of a display in different radiations (e.g. Hα, Hβ); these filters by relative enhancement of the auroral radiation will make observations possible during moonlight.
Lee waves ahead of a warm front
Authors: Wallington C. E.
Published: February 2007

A lee‐wave flight provides some observational evidence in support of a theoretical approach to the wave phenomenon and leads to a discussion on the nature of lee waves ahead of a warm front.
Gust variation with height up to 150 m
Authors: Deacon E. L.
Published: February 2007

Measurements, on occasions of strong wind, of horizontal wind gusts at heights of 12, 64 and 153 m in open country show the increase of gust speeds with height to be markedly less than that of mean wind speed. Lack of synchronism between gusts at the various heights makes it necessary, for wind‐pressure applications, to examine the maximum values of wind speed averaged over the three heights. At the times of occurrence of these maxima, the wind speed is approximately proportional to the height raised to the power 0·085. The corresponding index for the mean speed is 0·16.

Some results on the structure of turbulence are applied to enable predictions of extreme vertical gust velocities to be made.
The Ekman spiral
Authors: Ellison T. H.
Published: February 2007

Previous workers have used an eddy viscosity varying with height linearly or according to a power law, when discussing the variation of the wind between the surface and the height at which it (supposedly) attains the geostrophic value, but they have not used the appropriate boundary conditions to obtain the familiar forms for the velocity profile very near the surface. In conditions of neutral stability this profile is given by

where u* = (τ)1/2 and k = 0·40. Eq. (1) corresponds to an eddy viscosity, KM, given by

If this formula is assumed to hold at all heights, and the geostrophic wind is assumed to be uniform and constant, it can be shown that

where u is the component of the wind in the direction of the surface wind and v that perpendicular to it; the suffix G denotes the geostrophic value and f is the Coriolis parameter.
Dates of first or earliest snow covering for Tokyo since 1632
Authors: Arakawa H.
Published: February 2007

Dates of first or earliest snow covering for Tokyo are given in chronological order since 1632. Examination of this documentary evidence in Japan shows that the years since the end of last century have been characterized by later arrival of snow covering even though there is a definite sequence of fluctuation between warm and cold.
Water‐vapour flux and flux‐divergence over Southern England: Summer 1954
Authors: Hutchings J. W.
Published: February 2007

Average zonal (eastward) and meridional (northward) transfers of water vapour for the period June‐August 1954 are computed at four aerological stations in southern England ‐ Liverpool, Hemsby, Crawley and Camborne‐at levels corresponding to the earth's surface, 950, 900, 850, 800, 750, 650, 550, 450, and 350 mb.

In the zonal direction average transfers are eastwards and reach a maximum of 400–500 g (cm 100 mb sec)−1 below 900 mb. In the meridional direction both northward and southward transfers occur and their vertical distribution varies from station to station. Largest meridional transfers are of the order of 100 g (cm 100 mb sec)−1 and normally occur below 800 mb. Both zonal and meridional transfers become small near 350 mb. Vertically integrated eastward and northward transfers are respectively: Liverpool 1461, ‐13; Hemsby 1541, 226; Crawley 1701, 132; Camborne 1781, ‐42 g (cm sec)−1..

Average zonal eddy‐transfers are normally eastward and amount to only a small percentage of the total zonal transfer. Average meridional eddy‐transfers are northward, amount to a large percentage of the total meridional transfer and in some cases are oppositely directed. Vertically integrated eastward and northward eddy‐transfers are respectively: Liverpool 63, 73; Hemsby 81, 58; Crawley 97, 27; Camborne 113, 125 g (cm sec)−1. Although directed roughly from high to low values of average specific humidity, average eddy‐transfer vectors at a given (geometric or pressure) level bear little quantitative relation to average (horizontal or isobaric) specific humidity gradients at the same level.

Assuming the above transfers to vary linearly between stations, computation of the net horizontal outflow of water vapour from the region shows marked convergence of water vapour from the surface to 850 mb with divergence above this. For the three months' period this amounts to a net inflow of 31 g cm−2 at low levels and a net outflow of 23 g cm−2 at higher levels. Increase in storage amounts to approximately 1 g cm−2, thus leaving a surplus of precipitation over evaporation of approximately 7 g cm−2. Estimation of precipitation from isohyetal charts and evapotranspiration by empirical methods yields a corresponding surplus of 6 g cm−2..

Computation of the large‐scale vertical transfer of water vapour (using instantaneous kinematically‐computed vertical velocities) at 900, 800, 700 and 600 mb showed that at these levels large‐scale vertical eddy‐transfer of water vapour is negligibly small. Using mean vertical velocities and specific humidity averaged over the area at 950, 850, 750, 650, 550 and 450 mb, computations yield large‐scale upward transfers of water vapour for the three months' period amounting to 17, 23, 13, 6, 2, 0 g cm−2 respectively at the above levels. This flux is shown to be inadequate for water‐balance requirements and it is concluded that a considerable part of the upward transfer is carried by turbulent and convective systems of essentially smaller scales.
A preliminary study of atmospheric waves using radiosonde data
Authors: Corby G. A.
Published: February 2007

Evidence of atmospheric gravity waves, almost certainly due to orography, is obtained from a study of British radiosonde data. It is shown that such data can usefully be exploited to study some aspects of the flow of air in the neighbourhood of mountains.
Jet stream and long waves in a steady rotating‐dishpan experiment: Structure of the circulation
Authors: Riehl Herbert , Fultz Dave
Published: February 2007

The three‐dimensional structure of the flow of water in a steady rotating three‐wave dishpan experiment is computed and compared with the atmosphere.

At first the experiment and methods of comparison between dishpan and atmosphere are described. Then motion and vorticity at the top surface are shown; trajectories leading from equatorial to polar rim of the pan are found. Next the three‐dimensional temperature field is determined, and from this the geostrophic motion at all depths.

The flow pattern resembles the basic features of the middle‐latitude atmosphere in a remarkable way. Mobile long waves in a jet stream near the top overlie cyclonic and anticyclonic vortices farther down. There is, however, neither the counterpart of tropopause nor stratosphere in the temperature field, indicating that these features are not necessary for development of the basic flow pattern. Further, the distribution of momentum sources and sinks differs from that of the atmosphere, as momentum is given off to the inner (and possibly to the outer) cylinder, while most of the bottom acts as source. This throws doubt on the importance of momentum balance considerations for explanation of the principal flow features.

Vertical motions are calculated in the interior of the fluid with the adiabatic assumption. Values again compare well with those of the atmosphere as does the distribution of centres of ascent and descent relative to long waves and cyclones. A positive correlation between temperature and vertical motion exists along the jet axis, hence there is release of potential energy. If averaging is performed along the jet‐stream axis, one finds that the centre of ascent lies equatorward, and the centre of descent poleward of the axis. Ifzonalaveraging is performed, however, the centre of ascent appears north of the zonal wind maximum, and the centre of descent on its equatorward side. This calculation uncovers a weakness of zonal averaging as a tool in studying the general circulation.

Absolute vorticity is calculated on constant temperature surfaces in the interior of the liquid. It is found that the theorem of conservation of absolute vorticity is nearly fulfilled in the jet‐stream layer with wave motion; in the lower layer with vortices, validity of the theorem of conservation of potential vorticity is indicated qualitatively. The regions of convergence and divergence, as inferred from the vorticity changes along the relative stream‐lines, agree qualitatively with the vertical motion distribution.
Objective analysis in numerical forecasting
Authors: Bushby F. H. , Huckle Vera M.
Published: February 2007

This paper describes an objective technique for analysing sets of upper‐air data. The analyses resulting from the application of this technique to four sets of data for the NE Atlantic and Europe were compared with those produced subjectively by an analyst, and no marked differences were apparent.

Numerical forecasts for twenty‐four hours ahead based on both subjective and objective analyses were computed for these four situations and the results compared with the actual developments. Only slight differences were noticed between the forecasts based on the subjective analyses and those based on the objective analyses in three of the four situations, but in the fourth situation the numerical forecast based on the objective analysis was much the better.
Evidence of a mean meridional circulation in the atmosphere from surface wind observations
Authors: Tucker G. B.
Published: February 2007

Surface‐wind observations in the Northern Hemisphere are analysed and fields of mean meridional and zonal motion obtained. From these, profiles of mean meridional motion as a function of latitude are deduced. The results are consistent with a direct meridional circulation in low latitudes and an indirect circulation in mid‐latitudes, both attaining speeds of 1 to 2 m/sec at the surface. This scheme is found to be consistent with a decrease of upward flux of westerly momentum with height (convergence) in the surface layers in low latitudes and a decrease of downward flux in mid‐latitudes.
A preliminary investigation of long waves at Newlyn
Authors: Darbyshire J.
Published: February 2007

Long waves of period greater than 1/2 min are recorded at Newlyn, Cornwall. There are two predominant types; one with a period of approximately 12 min and another with a period of 30 to 40 min. This investigation deals only with the longer‐period type and is concerned with the eight instances during the period Mar. 1956 to Mar. 1957 where these longer waves exceeded 7 in. in amplitude.

The occurrence of these waves appears to be associated with the passage of meteorological fronts and a reasonable correlation is found between the amplitude and the northward component of the frontal velocity whilst the duration of the wave activity appears to decrease as the easterly component of the frontal velocity increases.

Various suggestions regarding the nature of these waves are considered. The evidence that they are edge waves is not very convincing and the most likely explanation appears to be that the waves are due to the oscillation of Mounts Bay as a whole, or of the north‐western part of it.
The determination of tropospheric ozone from infra‐red emission spectra
Authors: Goody R. M. , Roach W. T.
Published: February 2007

The emission spectrum of the sky has been measured on 127 occasions at Ascot in a period of 12 months in 1956 and 1957, and the observations have been interpreted in terms of the total amount of ozone between 1,000 and 300 mb. The ozone amount in this layer varies about a mean value of 13 × 10−3 cm STP and an individual determination is accurate to about ± 3 × 10−3 cm STP.

The results suggest that fluctuations in the total ozone amount are controlled by different mechanisms in spring and the rest of the year, and that during this period advection may be the dominating effect. There is evidence that some of the tropospheric ozone has come from the upper stratosphere, but it also seems probable that much has been advected into these latitudes.

Our results show very little relation to ground‐level chemical measurements made just after mid‐day. This disagreement might possibly be due to secondary sources of ozone near ground‐level.