bluuebunny/crossref_metadata_2025 huggingface dataset:
PREPARATION AND CHARACTERIZATION OF TiO2/SERICITE COMPOSITE MATERIAL WITH FAVORABLE PIGMENTS PROPERTIES
Authors: LIANG YU , CHEN WANTING , YANG GUANG , DING HAO , HOU XIFENG , RAN JUN
Published: August 2018

A unique method of preparing TiO2/sericite composite particles material was investigated by coating anatase TiO2 on the surface of sericite via chemical precipitation method. The results of X-ray diffraction, scanning electron microscope, infrared spectra and X-ray photoelectron spectroscopy indicated that TiO2 coated uniformly on the surface of sericite, and Si-O-Ti chemical bonds are formed during the thermal treatment process. The hiding power of Ti/SE-CPM composite is up to 85% of TiO2 white pigments, and the oil absorption value was equal to TiO2 white pigments. All these data demonstrated that the obtained Ti/SE-CPM samples have similar excellent properties compared with anatase TiO2 white pigments. Therefore, this study provides a feasible way of reducing the usage of TiO2 while maintaining similar pigment properties, which, of course, will reduce the cost, protect our environment and has a potential application in large-scale production of white pigments.
A Practical Wheel-Rail Interaction Element for Modeling Vehicle-Track-Bridge Systems
Authors: Gu Quan , Liu Yongdou , Guo Wei , Li Weiquan , Yu Zhiwu , Jiang Lizhong
Published: August 2018

A novel practical element is presented for simulating the vertical wheel-rail interaction (WRI) of vehicle-track-bridge (VTB) coupling systems. The WRI is time- and location-varying, which makes the simulation of the VTB system complicated. The new element simulates the WRI using a location dependent internal resisting force, which enables the finite element (FE) model of the VTB system to remain unchanged in analysis. This element is capable of simulating the nonlinear WRI, the rail irregularity and the ‘additional’ displacement of the rail. The ‘additional’ displacement is the extra displacement caused by the WRI besides that interpolated from the element nodal displacements, which is usually ignored by existing models, but may be non-negligible in some cases. The WRI element is implemented into a general FE software framework, OpenSees, and verified by the dynamic analysis of a simply-supported beam subjected to a moving sprung mass. Furthermore, a realistic VTB system with a moving four-wheel vehicle is investigated to evaluate the cases where the additional displacement and nonlinear WRI should be considered. Finally, using another realistic VTB system subjected to rail irregularities and earthquakes, the effects of rail irregularity and earthquake on the dynamic responses of the WRI system are studied and compared.
Innovation and Productivity in Services: A Methodological Approach
Authors: Lopes Luísa Ferreira , Godinho Manuel Mira
Published: August 2018

The purpose of this paper is to contribute to understanding innovation dynamics in services, in particular the link between innovation and productivity. A methodology to explain this link is suggested. Instead of establishing a single, direct connection between innovation and labor productivity, as in earlier approaches in the services literature, a simultaneous equations model is used. We put forward an extended version of the CDM (Crepon, Duguet and Mairesse) model, incorporating two feedback effects and using innovation activities rather than the more restrictive R&D proxy. Activities prior to the innovation implementation are also taken into account allowing for direct and indirect effects on labor productivity. Moreover, we discuss and handle the oftentimes overlooked methodological problems affecting this relationship. Micro data for ten service sectors in Portugal are used to estimate the model. The existence of a Schumpeterian virtuous cycle is confirmed, pointing to a mechanism reinforcing innovation investment returns. We find that innovation activities have a positive impact on labor productivity, but no evidence was found of a significant direct effect of innovation output. Labor productivity also improves with management capabilities. Relationships with customers, suppliers and cooperation partnerships significantly increase the probability of innovating, suggesting that stimulating organizational networking is a key element in a service firm’s innovation strategy.
Singular perturbation analysis of a two-site model for an epidemic in age-structured population
Authors: M'pika Massoukou Rodrigue Yves , Mambili-Mamboundou Hermane
Published: August 2018

We formulate a model describing the dynamics for the spatial propagation of an SIS epidemic within a population, with age structure, living in an environment divided into two sites. An analysis of the model is given. We prove the existence of a unique disease free equilibrium (DFE) and its (local and global) stability. Further, we assume that fast infection processes and fast migration processes take place in the above-mentioned model; i.e. such processes last only a few days (less than a week). In opposition to such processes, demographic processes such as birth, death and maturation last quite a lot of years. Such a gap between the time scales gives rise to a multiple time scales model, in particular a singularly perturbed model. Through a singular perturbation analysis, based on Tikhonov theorem, we prove that for certain classes of initial conditions the nonlinear perturbed model can be approximated with very good accuracy by lower-dimensional linear models.
Hopf bifurcation of a delay SIRS epidemic model with novel nonlinear incidence: Application to scarlet fever
Authors: Li Yong , Liu Xianning , Wang Lianwen , Zhang Xingan
Published: August 2018

An [Formula: see text] epidemic model incorporating incubation time delay and novel nonlinear incidence is proposed and analyzed to seek for the control strategies of scarlet fever, where the contact rate which can reflect the regular behavior and habit changes of children is non-monotonic with respect to the number of susceptible. The model without delay may exhibit backward bifurcation and bistable states even though the basic reproduction number is less than unit. Furthermore, we derive the conditions for occurrence of Hopf bifurcation when the time delay is considered as a bifurcation parameter. The data of scarlet fever of China are simulated to verify our theoretical results. In the end, several effective preventive and intervention measures of scarlet fever are found out.
A Granger Causality Analysis between the GDP and CO2 Emissions of Major Emitters and Implications for International Climate Governance
Authors: WANG Mou
Published: August 2018

This paper empirically examines the relationship between carbon emissions and economic growth by applying the co-integration analysis and Granger causality test to the time series data of carbon emissions and gross domestic product (GDP) of the world’s top 20 emitters from 1990 to 2015. Co-integration analysis shows that there is a long-term equilibrium relationship between carbon emissions and economic growth in most countries; Granger causality test verifies a one-way causal link between carbon emissions and economic growth in most major emitters. In developed countries, economic growth is the Granger cause of carbon emissions, while the opposite is true in developing countries. The results reflect different characteristics regarding carbon emission reduction in developed and developing countries as they are at different developing stages. Carbon emission reduction exerts much greater adverse effects on the economic growth of developing countries than it does on that of developed countries. Based on the results of the Granger causal analysis, it is found that the requirements for developing countries to substantially reduce emissions are not in line with the characteristics in their current developing stage and therefore may pose obstructions. Developed countries should take the lead in carrying out emission reductions due to their accountability for historical emissions as well as their development stages and capabilities. In addition, they should aid developing countries in their efforts for transforming and upgrading development and reducing dependence of economic growth on carbon emissions. International climate governance should take into account the needs and characteristics of different countries for future development, and build a mechanism for international cooperation to achieve synergy between social economic development and global climate governance.
Modeling and Detecting False Data Injection Attacks against Railway Traction Power Systems
Authors: Lakshminarayana Subhash , Teng Teo Zhan , Tan Rui , Yau David K. Y.
Published: August 2018

Modern urban railways extensively use computerized sensing and control technologies to achieve safe, reliable, and well-timed operations. However, the use of these technologies may provide a convenient leverage to cyber-attackers who have bypassed the air gaps and aim at causing safety incidents and service disruptions. In this article, we study False Data Injection (FDI) attacks against railway Traction Power Systems (TPSes). Specifically, we analyze two types of FDI attacks on the train-borne voltage, current, and position sensor measurements—which we call
efficiency attack
and
safety attack—
that (i) maximize the system’s total power consumption and (ii) mislead trains’ local voltages to exceed given safety-critical thresholds, respectively. To counteract, we develop a Global Attack Detection (GAD) system that serializes a
bad data detector
and a novel
secondary attack detector
designed based on unique TPS characteristics. With intact position data of trains, our detection system can effectively detect FDI attacks on trains’ voltage and current measurements even if the attacker has full and accurate knowledge of the TPS, attack detection, and real-time system state. In particular, the GAD system features an adaptive mechanism that ensures low false-positive and negative rates in detecting the attacks under noisy system measurements. Extensive simulations driven by realistic running profiles of trains verify that a TPS setup is vulnerable to FDI attacks, but these attacks can be detected effectively by the proposed GAD while ensuring a low false-positive rate.
Approximation Guarantees for the Minimum Linear Arrangement Problem by Higher Eigenvalues
Authors: Tamaki Suguru , Yoshida Yuichi
Published: August 2018

Given an
n
-vertex undirected graph
G
= (
V
,
E
) and positive edge weights {
w
e
}

e∈E

, a linear arrangement is a permutation π : V → {1, 2, …,
n
}. The value of the arrangement is
val
(
G
, π) := 1/n∑

e ={
u, v
} ∈
E

w
e

|π(
u
) − π (
v
)|. In the minimum linear arrangement problem, the goal is to find a linear arrangement π
*
that achieves
val
(
G
, π
*
) = MLA(
G
) := min
π
val
(
G
, π).

In this article, we show that for any ϵ > 0 and positive integer
r
, there is an
n

O
(
r
/ϵ)

-time randomized algorithm that, given a graph
G
, returns a linear arrangement π, such that

val
(
G
, π) ≤ (1 + 2/(1 − ε)λ
r
(
L
)) MLA(
G
) +
O
(√log
n
/
n
∑

e ∈ E

w
e

)

with high probability, where
L
is the normalized Laplacian of
G
and λ
r
(
L
) is the
r
th smallest eigenvalue of
L
. Our algorithm gives a constant factor approximation for regular graphs that are weak expanders.
P-FRP task scheduling with preemption threshold
Authors: Lin Jian (Denny) , Cheng Albert M. K.
Published: August 2018

Abort-and-Restart model is used in Priority-based Functional Reactive Programming in which higher priority tasks can preempt lower priority tasks and the lower priority tasks are aborted and restarted after the higher priority tasks have finished execution. This paper discusses a potential of improving schedulability in P-FRP systems by using preemption threshold that it allows a task to only disable preemption of tasks up to a specified threshold priority. Also, a sufficient schedulability test condition is studied in this paper for P-FRP tasks using preemption threshold, which is a critical problem to be solved in order to explore the potential benefit.
IGF1 suppresses cholesterol accumulation in the liver of growth hormone-deficient mice via the activation of ABCA1
Authors: Fukunaga Kensaku , Imachi Hitomi , Lyu Jingya , Dong Tao , Sato Seisuke , Ibata Tomohiro , Kobayashi Toshihiro , Yoshimoto Takuo , Yonezaki Kazuko , Matsunaga Toru , Murao Koji
Published: August 2018

Recently, several clinical studies have suggested that adult growth hormone (GH) deficiency that also has low concentration of IGF1 is associated with an increased prevalence of fatty liver (FL). ATP-binding cassette transporter A1 (ABCA1) is a pivotal regulator of lipid efflux from cells to apolipoproteins and plays an important role on formation of FL. In this study, we determined the effects of IGF1 on ABCA1 expression in GH-deficient mice to clarify its effects on FL. Western blotting, real-time PCR, and a luciferase assay were employed to examine the effect of IGF1. The binding of FoxO1 to the ABCA1 promoter was assessed by chromatin immunoprecipitation (ChIP) assay. Cholesterol accumulation was analyzed by Oil Red O stain and cholesterol content measurement. We confirmed that IGF1 upregulated the ABCA1 expression. The activity of a reporter construct containing the ABCA1 promoter was induced by IGF1, and this effect was blocked by LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Constitutively active Akt stimulated the ABCA1 promoter activity, and a dominant-negative mutant of Akt or mutagenesis of the FoxO1 response element abolished the effect of IGF1. A ChIP assay indicated that FoxO1 mediated IGF1 transcriptional activity by directly binding to the ABCA1 promoter region. For in vivo experiments, we used an inhibitor for the GH receptor (Pegvisomant) to reduce the IGF1 level. A high-fat diet induced FL in mice (C57BL/6J) given Pegvisomant treatment. IGF1 treatment stimulated ABCA1 expression to improve cholesterol accumulation in these mice. These results show that the PI3K/Akt/FoxO1 pathway contributes to the regulation of ABCA1 expression in response to IGF1 stimulation that suppressed FL in GH-deficient mice.
The Feature of Solitary Small Nodular Type of Hepatic Epithelioid Hemangioendothelioma
Authors: Kubo Norio , Harimoto Norifumi , Araki Kenichiro , Hagiwara Kei , Yamanaka Takahiro , Ishii Norihiro , Tsukagoshi Mariko , Igarashi Takamichi , Watanabe Akira , Miyazaki Masaya , Yokoo Hideaki , Kuwano Hiroyuki , Shirabe Ken
Published: August 2018

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare tumor. Preoperative diagnosis of HEHE is difficult because it does not manifest specific symptoms or tumor markers. We report a resected case of small and solitary HEHE. The patient, a 74-year-old man, had undergone surgical resection for left renal cell carcinoma 20 years ago. During follow-up, a tumor approximately 1.3 cm in diameter was detected by computed tomography (CT) at liver segment VIII. It showed isodensity in the arterial phase, low density in the portal venous phase, and homogeneous enhancement in the late phase on CT and magnetic resonance imaging (MRI). We performed hepatic resection of the right hepatic vein drainage area. A pathological diagnosis of HEHE was made. Although small and solitary HEHE is rare, an enhancement pattern in each phase on CT and MRI, using contrast media, can yield clues for the diagnosis of HEHE.
An Unusual Cause of Abdominal Ascites
Authors: Wong Kimberly A. , Olson Kristin A. , Chak Eric W.
Published: August 2018

Abdominal ascites is most commonly caused by portal hypertension from liver cirrhosis. When present, portal hypertension is associated with an elevated serum-ascites albumin gradient (SAAG) ≥1.1 g/dL. In contrast, a SAAG < 1.1 g/dL suggests malignancy, tuberculosis, pancreatitis, or nephrotic syndrome. Here, we present a case of low SAAG ascites caused by epithelioid peritoneal mesothelioma in a woman with no known liver disease. The diagnosis proved elusive until diagnostic laparoscopy with biopsy was performed.
The Fiscal Externalities of Charter Schools: Evidence from North Carolina
Authors: Ladd Helen F. , Singleton John D.
Published: August 2018

A significant criticism of the charter school movement is that funding for charter schools diverts money away from traditional public schools. The magnitude of such adverse fiscal externalities depends in part on the nature of state and local funding policies. In this paper, we examine the fiscal effects of charter schools on both urban and nonurban school districts in North Carolina. We base our analysis on detailed balance sheet information for a sample of school districts that experienced substantial charter growth since the statewide cap on charters was raised in 2011. We find a large and negative fiscal impact in excess of $500 per traditional public school pupil in our one urban school district, which translates into an average fiscal cost of about $3,600 for each student enrolled in charter schools. We estimate comparable to somewhat larger fiscal externalities per charter school pupil for two nonurban districts.
Austronea (Asparagaceae, Scilloideae), a new genus from southern Africa, including the description of seven new species
Authors: MARTÍNEZ-AZORÍN MARIO , CRESPO MANUEL B. , ALONSO-VARGAS MARÍA ÁNGELES , DOLD ANTHONY P. , PINTER MICHAEL , WETSCHNIG WOLFGANG
Published: August 2018

As part of a taxonomic revision of Urgineeae, combining morphological and genetic data from numerous samples from a large range of its distribution, here we describe Austronea, a new genus from South Africa and southern Namibia. This genus is related to Fusifilum based on general inflorescence and flower morphology, but it differs from it by the leaves usually leathery and sometimes thickened; the capitate to subcorymbose raceme commonly nodding at early developing stages; the reddish to green-yellowish tepals, rarely white (see flower buds), which are usually connate at the base to form a distinct cup and patent free lobes, rarely tepals nearly free from the base; the filaments linear to lanceolate, smooth or rarely papillate below; and the ovary green to yellow-orange. These differences are also supported by our genetic studies (not shown) in which Fusifilum and Austronea form two well supported sister clades. Seven new species of Austronea are described from South Africa and Namibia and 11 new combinations in the genus are presented. An identification key is provided for all 18 accepted species in the new genus.
A new species of Physiculus (Teleostei: Moridae) from the Cape Verde Islands (Eastern Central Atlantic)
Authors: GONZÁLEZ JOSÉ A. , TRIAY-PORTELLA RAÜL , BISCOITO MANUEL
Published: August 2018

A new species of Physiculus, P. caboverdensis n. sp., is described from the outer shelf and upper slope of the Cape Verde Islands. This species differs from all other congeners from the Atlantic Ocean by its peculiar dentition, composed of large fang-like teeth in both jaws, interspaced with smaller canine-like teeth, arranged in two series on upper jaw and one on lower. This is the tenth species of the genus to occur in the Atlantic Ocean and the third to be recorded from the Cape Verde Islands.
A new genus of the Tympanophorus lineage of the subtribe Anisolinina from Madagascar (Coleoptera: Staphylinidae: Staphylininae: Staphylinini)
Authors: JANÁK JIŘÍ
Published: August 2018

A new genus of the Tympanophorus lineage of the subtribe Anisolinina, Janalia gen. nov. with the type species Janalia jarmilae sp. nov., from East Madagascar is described and illustrated. A modified key to the genera of the subtribe Anisolinina is presented.
A new Mexican species of Chrysina Kirby (Coleoptera: Scarabaeidae: Rutelinae), with nomenclatural changes, new records, and a key to the C. quiche species group
Authors: MORA-AGUILAR EDER F. , CUROE DANIEL , DELGADO LEONARDO , RAMÍREZ-PONCE ANDRÉS
Published: August 2018

Chrysina chimalapensis new species (Coleoptera: Scarabaeidae: Rutelinae: Rutelini), from the region of Chimalapas, Oaxaca, Mexico is described and illustrated. A key to the species of the C. quiche species group is included. Plusiotis neotenochca Morón & Nogueira is placed as a new junior synonym of Chrysina paulseni Hawks, and C. aenigmatica (Morón) as a new junior synonym of C. modesta Sturm. Chrysina benesi from Guatemala, and C. quetzalcoatli from Nicaragua are recorded as new country records. Chrysina quetzalcoatli Morón and C. triumphalis Morón are also recorded for the first time for the state of Oaxaca, Mexico, and C. victorina (Hope) for the state of Veracruz, Mexico.
Two new feather mite species of the family Analgidae (Acariformes: Analgoidea) from the Rufous-collared Sparrow Zonotrichia capensis (Müller, 1776 (Passeriformes: Passerellidae)
Authors: PEDROSO LUIZ GUSTAVO A. , HERNANDES FABIO AKASHI
Published: August 2018

Two new feather mite species of the family Analgidae are described from the Rufous-collared Sparrow, Zonotrichia capensis (Müller, 1776) (Passeriformes: Passerellidae), from Brazil: Analges ticotico sp. nov. (Analginae) and Strelkoviacarus brasiliensis sp. nov. (Anomalginae). Analges ticotico sp. nov. is characterized by the heteromorphic males having three short and rounded spines on the inner margin of femur III, the anterior margin of adanal shield convex, the hysteronotal shield with the anterior margin sinuous, and the terminal lamella rectangular. Strelkoviacarus brasiliensis sp. nov. is characterized by the anterior ends of the adanal shields being convergent and encompassing the bases of setae ps3 in males, and by the strongly convex median extension of the prodorsal shield and short dorsal setae vi, c2, d2 and e2 in females. These species represent the first records of corresponding feather mite genera in Brazil.
First Trials of the Schaefer-Langmuir Dry-Ice Cloud Seeding Technique in Hawaii **
Authors: Leopold Luna B. , Halstead Maurice H.
Published: August 2018

To determine tentatively whether rain from cumulus clouds could be induced in temperatures above freezing, 15 tests totalling 54 seedings were made with dry ice. In 20 of these rain or virga was observed to come from the seeded cloud, and generally in less than 16 minutes after seeding. In one case, as much as 1.25 inches of rain fell from the seeded cloud. Cloud thickness is a significant factor distinguishing the tests resulting in rain as against no rain.
A New Gradient-Wind Nomogram*
Authors: Godson W. L.
Published: August 2018

A nomographic solution is found for the gradient-wind equation in terms of the curvature of pressure-contour lines and the motion of pressure-contour systems. From the nomogram the gradient wind can be found as a function of the geostrophic wind, and in addition the radius of curvature of the trajectory can be evaluated. Subsidiary aids in determining the quantities involved are discussed, as well as the application of the computing device to routine upper wind forecasting.
An Objective Method of Forecasting Visibility1
Authors: Miller James E. , Mantis Homer T.
Published: August 2018

An objective method of forecasting visibility at La Guardia Field, N. Y., in the winter season, is developed from data for the winter of 1943–44 and tested in the winter of 1944–45. The method is based on 24-hr air trajectories, which are forecasted by a carefully prescribed, routine procedure. The visibility at the origin of a trajectory, the location of the origin, and the final wind velocity implied by the last segment of the trajectory, are combined by means of forecast charts and a formula, to produce a 24-hr forecast of the visibility. Tests of the method show that its accuracy is not much different from the accuracy of visibility forecasts for La Guardia by other methods, but it is pointed out that an objective procedure has certain advantages over the normal subjective forecasting methods.
A Study in Objective Forecasting
Authors: Gringorten Irving I.
Published: August 2018

Meteorological parameters can be divided into predictors and predictands, with the former being used to predict the latter. This report describes a project in which some 20 predictors were used to predict fog and stratus at Randolph Field, Texas, in competition with usual methods of the regular weather station there. The results yielded an overall increase in forecasting accuracy and skill by the objective system. But the most important feature of the objective system is that it enables one to state the probability of occurrence of each event.
Ice Fogs in the Interior of Alaska
Authors: Oliver V. J. , Oliver M. B.
Published: August 2018

Visibilities of 100 to 200 miles over large areas are reported by pilots flying in the Arctic winter of interior Alaska. However, when the airport is reached, they find ice fog and visibility near zero. This condition is described and reasons are presented for ice fog formation and persistence in the vicinity of towns while other areas equally cold remain fog free.
Examples of Topographic Convergence in the Equatorial Zone Between 95° E. and 160° E *
Authors: Glenn A. H.
Published: August 2018

Examples of convergence caused by effects of land masses on low-level circulation in the equatorial zone between 95 °E. and 160°E. are shown. Explanations are found, which accord with available observations and provide a satisfactory basis for forecasting. Wind-tunnel study of a model is suggested as the most practical and economical means of analyzing qualitatively the small-scale convergence features of this region.
Micrometeorology in the Tropics *
Authors: Hales Wayne B.
Published: August 2018

Thermistor bead thermometers and anemometers were used to record the micrometeorological changes in temperatures and wind speeds in the jungles of Panama. Twenty-four hour continuous observations were made through a layer of atmosphere up to 160 feet from which temperature and wind-speed gradients were determined above and below the canopy. Graphs are supplied to show hourly and vertical trends.
An Instrument That Records the Oxidizing Effect of the Air
Authors: Dirnagl Carl
Published: August 2018

The previous attempts to measure ozone near the ground are reviewed. As the methods of Paneth, Cauer and Regener are not suited for routine continuous bioclimatic purposes a new apparatus is developed, making a continuous record with the KI-starch paper principle. This measures the total oxidizing power of the air due to ozone and its byproducts (“aran”).
Changes in Vertical Mass Distribution Over Rapidly Deepening Lows
Authors: Vederman Joseph
Published: August 2018

Changes in thickness of the “standard” layers of the central column of 25 rapidly deepening storms are investigated. It is found that the lower two-thirds by weight of the central column becomes thinner (colder and denser) as a storm deepens. The upper one-third of the central column becomes “thicker” and warmer by an amount sufficient to counteract the action of the lower layers and an additional amount to deepen the Low. The Low of November 21–22, 1945, is discussed. Bjerknes' theory of the deepening of extratropical cyclones is compared with the data.
An Evaluation of Dew Point Fluctuations in the Microclimatic Layer 1
Authors: Shaw R. H. , Waggoner Paul E.
Published: August 2018

Measurements of the diurnal and height variation of the dew-point temperature in three types of ground cover (corn, soybeans and bare ground) were made in 1948 at Ames, Iowa, using a photoelectric dew-point hygrometer. The variations are expressed as the standard deviation of a frequency distribution of the dew-point temperatures taken at half-second intervals during a minute run.
An Objective Determination of Probability of Fog Formation *
Authors: Berkofsky Louis
Published: August 2018

A method of approach to objective fog forecasting, based on the use of probability charts is suggested. Given two parameters, say wind speed and dew-point depression, at sunset as ordinate and abscissa of a chart, occurrences and non-occurrences of fog following sunset are plotted as functions of these parameters. Isolines of relative frequency are drawn, giving a probability chart. Two more such charts, using four additional parameters, are constructed, and a total probability of fog occurrence following sunset is computed as a linear function of the three individual probabilities. This result is used as a criterion for the forecast. Time of formation equations are developed, to be applied in the event a fog proves to be likely.
The Winter Mid-Troposphere Circulation Near the North Pole
Authors: Vederman Joseph , Smith Clarence D.
Published: August 2018

With the aid of observations at 500 mb taken by the Ptarmigan reconnaissance flight to the North Pole the mean fields of temperature, height, and wind for the region from the northern edge of the North American Continent to the North Pole for the first three months of 1949 are computed. The resulting picture is compared with previous concepts of upper-air conditions in the Far North. The 500-mb charts for the days with lowest and highest elevations of that surface are given. Profiles of temperature, height, and wind from near the Equator to the North Pole for these days are also given. An attempt is made to determine the rate of subsidence of the air at 500 mb in the vicinity of the North Pole.
An Improved Fully Electric Radiosonde *
Authors: Sittel Karl , Menzer Ernst
Published: August 2018

A fully electric radiosonde using the Finnish principle is described. The temperature is measured with a temperature sensitive dielectric; the humidity by the determination of the psychrometric difference; and the pressure by a corrugated diaphragm which positions a cylindrical condenser. The measuring elements and the construction of the sonde, as well as the calibration and receiving station, are outlined. The more important phases of the investigation are briefly mentioned, and a comparison of the temperature measurement with a number of other sondes is given.
An Appraisal of Cloud Seeding as a Means of Increasing Precipitation
Authors: Houghton Henry G.
Published: August 2018

The results of cloud-seeding experiments are reviewed briefly and it is concluded that, taken alone, they do not constitute an adequate basis for a sound appraisal of the potentialities of the cloud seeding techniques. An attempt is made to extend and supplement the observational evidence with the aid of existing knowledge of cloud physics and synoptic meteorology. It is found that significant amounts of precipitation can fall only from clouds which are continuously replenished. It is concluded that the thermal effects of seeding are seldom sufficient to stimulate the vertical development of a cloud. Since the activation-temperatures of the artificial ice-nuclei are believed to be higher than the activation-temperatures of natural ice-nuclei there is a possibility that seeding may advance the onset of precipitation or release precipitation from clouds which do not extend to the activation-temperature of the natural ice-nuclei. It appears that the seeding of clouds which are already releasing precipitation may either decrease or increase the total precipitation; an unequivocal answer is not possible due to the lack of pertinent information regarding natural precipitation processes. On the basis of the analysis of the physical processes and general knowledge of synoptic meteorology it is concluded that it is unlikely that cloud seeding will cause large-scale effects. Further research on cloud physics and cloud seeding is recommended.
Radar Observations of a Frontal Storm
Authors: Austin Pauline M.
Published: August 2018

The development of frontal precipitation as observed by radar is illustrated by data taken on a particular storm. This storm presents a typical sequence of precipitation patterns found to be associated with a warm front and a following cold front.
The Use of Confidence Factors in Forecasting
Authors: Williams Philip
Published: August 2018

The history, use and need for confidence factors with forecasts is discussed briefly. A trial of their use made by Weather Bureau staff forecasters at Salt Lake City indicates that forecasters are well aware of the likelihood of their forecasts verifying, and the use of confidence factors with subjective forecasts appears to be feasible.
A Low-Pressure Hydrogen Generator for Use in Filling Radiosonde Balloons
Authors: Gill Gerald C.
Published: August 2018

At weather stations outside of the United States meteorological balloons are usually inflated with hydrogen. At stations remote from large industrial centers it is usually cheaper to generate the hydrogen at the station than to ship it in cylinders from the industrial center. Probably the most common hydrogen generator for station use is of the high pressure chemical style where pressures in excess of 2000 p.s.i. are not uncommon. To reduce the number of serious accidents occurring through the use of these high pressure generators, a low pressure generator with a maximum pressure of 4 p.s.i. has been developed.
The Development and Motion of Typhoon “Doris,” 1950
Authors: Cressman George P.
Published: August 2018

The development and motion of typhoon “Doris,” which was observed during the first two weeks of May, 1950, are studied. The development of the storm is examined with respect to previously published theories of storm formation. The original deepening occurred in the low latitude portion of an extended trough, after the fracture of the trough. This is in agreement with a model proposed by Riehl. The motion of the deepening storm relative to the high-level flow patterns differed from previously studied examples in that the deepening occurred as the low-level cyclone moved from under the west side of an upper anticyclone toward a position under an upper cyclone. The storm developed as two cyclonic vortices, which gradually merged into one, in agreement with a principle of Fujiwhara.

The motion of the storm northward, as it broke through the subtropical ridge line, is shown. After examination of several possibilities, this motion is attributed to the resultant of all the Coriolis forces acting on the storm, as discussed by Rossby. The suggestion is made that this resultant force becomes prominent in determining the motion of the storm due to changes in the radial velocity profile and the increasing geographical extent of the storm.
Frontal Microseisms *
Authors: Gilmore Marion H.
Published: August 2018

The Microseismic Research Project, initiated by the Naval Aerological Service, has recently completed a detailed study of microseisms associated with cold fronts. The data presented in this paper concerning frontal microseisms, together with data previously published concerning tropical storm microseisms, lead to the conclusion that most microseismic storms are a direct function of the wind force, the density of the air mass involved and the area over which the force acts. Most reliable sources of information also lead to the conclusion that microseismic storms are generated on the ocean bottom directly under the storm area, probably by means of compressional water waves set up by the storm.
Spray-Nozzle Type Silver-Iodide Smoke Generator for Airplane Use *
Authors: Vonnegut Bernard , Maynard Ktah
Published: August 2018

A spray nozzle type silver iodide smoke generator has been constructed that is suitable for airplane operation. This apparatus has been used successfully to seed cumulus clouds and to produce trails of ice crystals in regions of the atmosphere supersaturated with respect to ice.
The Effect of Relative Humidity on the Nucleating Properties of Photolyzed Silver Iodide *
Authors: Birstein S. J.
Published: August 2018

The effect of adsorbed water vapor on the photolysis of silver iodide has been studied. Inn has found that when silver iodide nuclei are exposed to ultraviolet light before injection into a cold chamber containing a cloud of supercooled water droplets, no ice formation is observed. Reynolds, Hume, Vonnegut and Schaefer have investigated the effect of bright sunlight on the action of silver iodide as a sublimation nucleus, and have found a decrease in the magnitude of nucleating effectiveness which is less than that observed by Inn.

The studies in this laboratory have been concerned with the effect of relative humidity on the photolysis and subsequent nucleating properties of silver iodide particles. Known amounts of water vapor were introduced into a stream of nitrogen passing over a silver iodide generator. The silver iodide particles, covered with adsorbed water, were collected in a cell and exposed to ultraviolet light of known intensity for varying amounts of time. After irradiation, the silver iodide particles were injected into a cloud of supercooled water droplets and ice formation was watched for. The nucleating effectiveness of silver iodide exposed to ultraviolet light was found to be directly dependent on the relative humidity of the gas stream passing over the generator.
The Effect of Protracted Spring Thaws on Ice Conditions in Hudson Bay *
Authors: Mackay G. A.
Published: August 2018

The extent of ice cover in Hudson Bay was investigated during the Spring of 1948 by the RCAF and interested governmental departments. A series of reconnaissance flights over the Bay in March and April disclosed that it was virtually ice-bound from shore to shore. Large areas of open water were observed during the period May 3rd to May 6th. An inspection of the synoptic weather charts disclosed that weather conditions over the Bay both prior to and during this period were abnormal. This immediately suggests that the ice conditions observed might not be representative. For an appraisal of the observations it is necessary to determine the effects of the abnormal weather on the ice. The observed ice conditions are mentioned and the causes of open water areas briefly discussed. The severity of the winter at Churchill was investigated to determine the normalcy of the ice development. A protracted thaw over the eastern parts of Hudson Bay is disclosed by reference to the weather charts. The correlation between the mean monthly temperatures for the spring months and the date of ice clearance at Churchill Harbour is then investigated to determine the effects of a protracted thaw on the ice.
Recent Developments in Radio Location of Thunderstorm Centers *
Authors: Kessler W. J. , Hersperger S. P.
Published: August 2018

The location of thunderstorms through observations of the directions of arrival and the instantaneous intensity variations of the electromagnetic radiations produced by the associated lightning discharges is described. The method of triangulation (θ1, θ2), employed by the Air Forces during World War II, and the proposed single-station (R, θ) technique currently under investigation at the University of Florida are discussed.
Some Dust Storm Conditions of the Southern High Plains
Authors: Warn G. Frederick
Published: August 2018

This paper summarizes some of the weather conditions which cause blowing dust in the Southern High Plains of Texas. These conditions include diurnal winds, whirlwinds and thunderstorms. A tentative classification of dust storms in this area is given in table form. The terms dust lift, dust swath, and dust ring are introduced.
Variation of Rainfall Over South China Through the Wet Season
Authors: Ramage C. S.
Published: August 2018

Five-day means show that over south China there are certain persistent variations in the march of rainfall during the wet season (March–November). These are explained in terms of seasonal meteorological trends in the surrounding regions. The view is advanced, supported by an ancient Chinese farmers' calendar, that the rainfall pattern of south China has changed little in the past 2000 years.
A New Sunshine Recorder *
Authors: Taylor Charles L.
Published: August 2018

A new type of sunshine recorder has been developed; its design is based on the principle of a differential air thermometer. Simultaneous laboratory tests show that the instrument responds more rapidly and exhibits greater sensitivity than does the Marvin-type instrument.
Utility of Radar in Measuring Areal Rainfall *
Authors: Stout G. E. , Neill J. C.
Published: August 2018

Areal rainfall distribution over a 50-square-mile area was observed by 3-cm radar and by a rain-gage network of 33 rain gages. Isohyetal maps were prepared from both rain-gage and radar observations in order to compare the rainfall distribution as observed by the two rainfall observation techniques. The computed rainfall values were at least as accurate as those obtained by a rain-gage network of one gage per 200 square miles and in some cases they were considerably more accurate.
Verification of a Formula for the Growth of Troughs and Wedges
Authors: Ernst F. W. , Fox Roy L. , Hutchison H. E.
Published: August 2018

A formula for the instantaneous growth rate of vorticity waves was tested on 152 contour troughs and 101 contour wedges at the 500-millibar level. It was found that the formula could be used qualitatively for determining whether individual troughs and wedges will intensify or weaken over periods of 24 hours, without carrying out the laborious computations required by an exact application of the formula. Further examination of data showed that cut-off lows formed in pre-existing troughs most readily when the negative tilt of the troughs was greater than 15°, or strong asymmetry was present.
On a Relationship Between Evaporation and Evapotranspiration
Authors: Neumann J.
Published: August 2018

Heat balance considerations indicate that the annual amount of evaporation from an extensive water surface is greater by some 33 percent than evapotranspiration from an extensive vegetation-covered land surface having an ample supply of water. The assumption is that the same amount of insolation reaches both surfaces. Turbulence theory is used to show that the above estimate leads to values of the friction velocity (or shearing stress) which are in close agreement with independent results for vegetation-covered land surfaces, indicating the correctness or approximate correctness of the above estimate. The assumption of the demonstration is that the geostrophic wind is the same over both surfaces. It is estimated that the annual amount of sensible heat transferred from the vegetation-covered land surface is some 5 to 10 percent of the insolation reaching that surface.
On Changes in the Zonal Wind Profile and Their Relations to Forecasting
Authors: Snellman Leonard W.
Published: August 2018

Changes in the hemispheric zonal wind-profile were used at the USAF South Ruislip Weather Central in England as one forecast tool to help in constructing prognostic charts for 48 hours and occasionally for 96 hours. The successes and failures of this technique during the period February to October 1952 are discussed. Suggestions for the improvement of its use on a daily basis are put forth.
Some Possible Reductions in Gust Loads Through Use of Radar in Transport Airplanes*
Authors: Tolefson H. B.
Published: August 2018

Turbulence measurements taken in different weather conditions are analyzed to obtain an estimate of the possible reductions in gust loads and increases in passenger comfort that might be realized by airlines through use of radar for detecting and avoiding storm areas. The results indicate that a 10 percent reduction might be obtained in the magnitude of the largest gust loads which are pertinent to the ultimate strength requirements of airplane structures. It appears, however, that little, if any, reduction would be realized in the small and more numerous gusts which are important to the fatigue life of the structure. On the question of passenger comfort, the number of uncomfortable flights experienced on the airlines would probably be reduced by a considerable amount when radar is used in transports. Evidence obtained to date on contour radar indicates that the contour attachment would be desirable for selecting the smoothest flight path through the storms that could not be avoided.
Remarks on the Development of the Coriolis Principle
Authors: McDonald James E.
Published: August 2018

Certain shortcomings in existing presentations of the Coriolis principle are discussed. These center about a common failure to develop a sufficiently clear understanding of the role played by the reference system in Newtonian mechanics. A systematic development of the Coriolis principle is outlined as an example of how some of the shortcomings may be met.
A Method for Forecasting Hailstone Size at the Earth's Surface*
Authors: Fawbush Ernest J. , Miller Robert C.
Published: August 2018

All upper-air soundings in the United States have been evaluated since January 1, 1950 and 274 selected as representative of air in which hailstones of known size formed. These soundings are summarized and several parameters which are or may be useful in forecasting are discussed. A graph is presented, which permits the translation of a forecast of air structure into one of hailstone size and two groups of forecasts are summarized to show the validity of this forecasting tool. The forecasts discussed were prepared in practical situations by meteorologists on regular forecasting duty and issued before the storms occurred. They therefore constitute a real test of the method under working conditions.

Evidence is presented to show a very striking relation between the incidence of surface hail and the height of the wet bulb freezing level above the terrain. It was found that in 91.6% of the 274 representative soundings, the wet bulb freezing levels were between 5000 and 12,000 feet above the surface and the larger the reported surface hail, the greater the concentration of these levels near 8000 feet.

It is emphasized that the method of hail forecasting discussed is not susceptible to machine methods, but depends on accurate prognostication of the thermodynamic structure of the air column as it changes in time and space.
Forecasting Rain-or-Snow at Denver, Colorado, September–November
Authors: Laird Harley B. , Dickey Woodrow W.
Published: August 2018

Assuming the precipitation forecast for the period 14 to 26 hours beyond the forecast time is correct, the problem of deciding whether this precipitation is to be rain or snow is explored. A method of using the 700 millibar chart in making this decision is presented, together with conclusions verified in the form of skill score and percent correct.
A Method for Applying Tilted-Trough Theory to Synoptic Forecasting in the Mid-Troposphere
Authors: Oliver Vincent J. , Oliver Mildred B.
Published: August 2018

Rules have been developed for weather forecasting based on the recent researches in transport of momentum. The tilt and curvature of the upper level trough lines give information on the type of changes of circulation currently in process.
Recording Horizontal Atmospheric Transmission of Light at Night
Authors: Pearson C. A.
Published: August 2018

A photoelectric telephotometer, which measured the illumination produced at a fixed distance from a light source of known candle power, was developed to record directly the total horizontal atmospheric transmission of light at night over a two sea-mile path. The apparatus consisted of a multiplier phototube, a DC amplifier, batteries for operation, and a one-milliampere recorder. It can be set up easily for field use. A 1000-watt projection-type lamp was used as a light source. By means of a standard lamp, the photoelectric telephotometer was calibrated in a laboratory light tunnel to record illumination in sea-mile candles. In the field the photoelectric telephotometer was compared with a visual telephotometer. Transmission measurements showed good agreement between the photoelectric and the visual methods.
Use of Anomalies in the Design of a Hydrostatic Computer
Authors: Lally Vincent E.
Published: August 2018

The use of deviations from standard values rather than the use of absolute values enables computations to be made with lower precision without any accompanying loss in accuracy. Computation of the altimeter correction rather than the absolute height permits the desigh of a hydrostatic computer with a tenfold increase in accuracy when employing computing elements of similar precision.