scholarly journals On the extraction of electrons from cold conductors in intense electric fields

1928 ◽  
Vol 117 (778) ◽  
pp. 719-730 ◽  
Keyword(s):  
Continuous Function ◽  
Electric Fields ◽  
Applied Voltage ◽  
Thermionic Emission ◽  
Rapid Progress ◽  
Strong Fields ◽  
Wide Range ◽  
Firm Basis ◽  
Made In ◽  
Field Strengths

The discovery of this phenomenon seems to have evolved gradually from Earhart's* experiments on very short sparks in 1901. Since 1913 I have been familiar with the fact that in strong fields cold discharges could be made to pass in highly exhausted tubes under conditions which seemed to preclude the co-operation of gas as a factor. The phenomena appeared erratic and difficult to interpret. Recently, rapid progress has been made in the investigation of this effect especially owing to the researches of Gossling and of Millikan and Eyring, which have put it on a firm basis. Both Gossling and Millikan and Eyring have found, among other interesting facts, that with field strengths of the order of one million volts per cm. electrons can be drawn out of tungsten without the co-operation of gas, that the currents vary very rapidly with the applied voltage, and under proper conditions the current is reproducible and a continuous function of the applied voltage over a wide range, and that the currents at a given voltage are independent of the temperature provided the temperature is not so high as to approach the temperatures at which thermionic emission becomes appreciable.

scholarly journals Probing the Dark Secrets of PNe with ORLs

2003 ◽  
Vol 209 ◽  
pp. 339-346 ◽  
Author(s):  
X.-W. Liu
Keyword(s):  
Temperature Fluctuations ◽  
Small Mass ◽  
Electron Systems ◽  
Rapid Progress ◽  
Significant Progress ◽  
Element Abundances ◽  
Wide Range ◽  
Recombination Spectrum ◽  
Detector Technology ◽  
Made In

There are two long-standing problems in nebular astrophysics: a) The dichotomy of abundance determinations whereby heavy element abundances relative to hydrogen from collisionally excited lines (CELs) are systematically lower than those from (much fainter) optical recombination lines (ORLs), a discrepancy that can be traced back to Wyse (1942) and Aller & Menzel (1945) who pioneered the ORL method; and b) The dichotomy of temperature determinations whereby Te derived from the collisionally excited [O III] forbidden line ratio is systematically higher than that derived from Balmer jump of the H I recombination spectrum, a discrepancy first discovered by Peimbert (1971) and attributed to temperature fluctuations in the nebula (Peimbert 1967). Thanks to the rapid progress in detector technology and recombination theory for multi-electron systems, significant progress has been made in recent years in our understanding of these two fundamental problems, which could potentially affect the derivation of abundances for a wide range of photoionized nebulae, both galactic and extragalactic. Both types of dichotomy are found to be real and are most likely caused by astrophysical effects rather than uncertainties in observations or in the basic atomic physics. The two problems are shown to be related and can be explained by assuming that PNe contain a small mass of extremely cold (Te ~ 103 K) inclusions, highly enriched in helium and heavy elements, embedded in diffuse material of “normal” abundances (~ solar) and temperature (Te ~ 104 K). The existence and nature of such H-deficient inclusions in PNe remains a mystery. A recent review on this subject is given by Liu (2002).

I.—The Action of “Active” Nitrogen on Iodine Vapour

1929 ◽  
Vol 48 ◽  
pp. 1-9
Author(s):  
L. H. Easson ◽  
R. W. Armour
Keyword(s):  
Chemical Kinetics ◽  
Chemical Reaction ◽  
Electronic Energy ◽  
Chemical Investigation ◽  
Rapid Progress ◽  
Active Nitrogen ◽  
Spectroscopic Observations ◽  
Wide Range ◽  
Band Spectra ◽  
Made In

The rapid progress which has been made in the last few years in the knowledge of the rotational, vibrational, and electronic energy of molecules has extended the range of chemical investigation, particularly in the region of chemical kinetics. This knowledge is derived chiefly from the study and interpretation of band spectra, and one of the most obvious cases to examine is that of “active” nitrogen which emits a characteristic spectrum and is capable of energetic chemical reaction with a wide range of substances. For most of the early work, including spectroscopic observations, we are indebted to the excellent and thorough investigations of Strutt.

Comparison of random field strengths in (1-x)SrTiO3-xBiFeO3 and (1-x)SrTiO3-xBaTiO3 relaxor ferroelectrics by means of acoustic emission

2020 ◽  
Vol 92 (2) ◽  
pp. 20401
Author(s):  
Evgeniy Dul'kin ◽  
Michael Roth
Keyword(s):  
Acoustic Emission ◽  
Random Field ◽  
Electric Fields ◽  
Bias Field ◽  
Relaxor Ferroelectrics ◽  
External Bias ◽  
Field Strengths

In relaxor (1-x)SrTiO3-xBiFeO3 ferroelectrics ceramics (x = 0.2, 0.3 and 0.4) both intermediate temperatures and Burns temperatures were successfully detected and their behavior were investigated in dependence on an external bias field using an acoustic emission. All these temperatures exhibit a non-trivial behavior, i.e. attain the minima at some threshold fields as a bias field enhances. It is established that the threshold fields decrease as x increases in (1-x)SrTiO3-xBiFeO3, as it previously observed in (1-x)SrTiO3-xBaTiO3 (E. Dul'kin, J. Zhai, M. Roth, Phys. Status Solidi B 252, 2079 (2015)). Based on the data of the threshold fields the mechanisms of arising of random electric fields are discussed and their strengths are compared in both these relaxor ferroelectrics.

1989 göçü sonrası Bulgaristan göçmenlerinin yemek kültüründeki değişim

2017 ◽  
Vol 4 (2) ◽  
pp. 227-245
Author(s):  
Cahit Kahraman ◽  
İlhan Güneş ◽  
Nanae Kahraman
Keyword(s):  
Eating Habits ◽  
Supply And Demand ◽  
Food Culture ◽  
Rapid Progress ◽  
Canned Food ◽  
Product Range ◽  
The World ◽  
Before And After ◽  
Day By Day ◽  
Made In

1989 göçü öncesi, dünyada eşzamanlı olarak gittikçe gelişen ve zenginleşen mutfak kültürü, Bulgaristan Türklerini de etkilemiştir. Pazardaki çeşitlilik arttıkça, yemek alışkanlıkları da değişime uğramıştır. Büyük göçten sadece 30-40 sene evvel kısıtlı imkânlar ile sınırlı sayıda yemek çeşidi üretilirken, alım gücünün artmasıyla yemek kültüründe de hızlı gelişmeler olmuştur. Artan ürün çeşitliliği yemeklere de yansımış, farklı lezzetler mutfaklara girmiştir. Göçmen yemekleri denilince hamur işleri, börek ve pideler akla gelir. Ayrıca, göçmenlerin çok zengin turşu, komposto ve konserve kültürüne sahip oldukları da bilinir. Bu çalışma, 1989 öncesi Bulgaristan’ın farklı bölgelerinde yaşayan Türklerin yemek alışkanlıklarına ışık tutmakla birlikte, göç sonrasında göçmen mutfak kültüründe bir değişiklik oluşup oluşmadığını konu almaktadır. Bu amaçla, 1989 yılında Türkiye’ye göç etmiş 50 kişiye 8 sorudan oluşan anket düzenlenmiştir. Bu verilerden yola çıkarak oluşan bulgular derlenmiş ve yeni tespitler yapılmıştır. Ayrıca, Türkiye’nin farklı bölgelerine yerleşen göçmenler, kendi göçmen pazarlarını kurmuşlardır. Bulgaristan’dan getirilen ürünlerin bu pazarlarda satılması böyle bir arz talebin hala devam ettiğine işaret etmektedir.ABSTRACT IN ENGLISHThe Diversity in Cuisine Culture of the Immigrants from Bulgaria After 1989 MigrationThe Cuisine culture that has been developing and getting rich day by day contemporaneously in the world before 1989 migration has also had an impact on Bulgarian Turks. By the increase in diversity in the market, eating habits have changed. While producing a limited number of food types with limited opportunities just some 30 or 40 years before the ‘Big Migration’, there has been a rapid progress in food culture by the help of the increase in purchase power. Enhancing product range has been reflected in food, and different tastes have entered the cuisines. When we say immigrant, the first things that come to our mind are pastry, flan and pitta bread. Moreover, it is also known that immigrants have a very rich cuisine culture of pickle, stewed fruit, and canned food. This study aims both to disclose the eating habits of Turks living in different regions of Bulgaria before 1989 and to determine whether there has been a difference in immigrant cuisine culture before and after the migration. For this purpose, a questionnaire consisting of 8 questions has been administered to 50 people who migrated to Turkey in 1989. The results gathered from these data have been compiled and new determinations have been made. In addition, immigrants that settled in different regions of Turkey have set their own immigrant markets. The fact that the products brought from Bulgaria are being sold in these markets shows that this kind of supply and demand still continues.

PARAMETRIC MODEL OF RESISTANCE OF PLASMA-EROSIVE LOAD, ADEQUATE IN THE WIDE RANGE OF CHANGE OF APPLIED VOLTAGE

2017 ◽  
Vol 2017 (3) ◽  
pp. 3-12 ◽  
Author(s):  
N.A. Shydlovska ◽  
◽  
S.M. Zakharchenko ◽  
O.P. Cherkaskyi ◽  
◽  
...  
Keyword(s):  
Applied Voltage ◽  
Parametric Model ◽  
Wide Range

The Influence of Barrier and Applied Voltage Parameters on the Impulse Surface Discharge Characteristics

2020 ◽  
Vol 11 (11) ◽  
pp. 17-27
Author(s):  
Vadim V. VOEVODIN ◽  
◽  
Marina V. SOKOLOVA ◽  
Viktor R. SOLOV’YEV ◽  
Nikolay Yu. LYSOV ◽  
...  
Keyword(s):  
Applied Voltage ◽  
Voltage Pulse ◽  
Discharge Zone ◽  
Surface Discharge ◽  
Initial Surface ◽  
Barrier Material ◽  
Dielectric Barrier ◽  
Discharge Ignition ◽  
Study Results ◽  
Wide Range

The results from an experimental study of impulse surface discharge occurring in an electrode system containing a dielectric plate are presented. On one of its sides, the plate had a corona-producing electrode made of 50 mm thick copper foil grounded through a current shunt for measuring the discharge current. On its other side, the plate had a high-voltage electrode, to which the voltage from a pulse generator was applied. The article presents the results from measurements of the initial voltage and the sizes of the surface discharge area in air when applying single voltage pulses with different pulse front steepness in the range 0,1–3,4 kV/ms and amplitude in the range 7–15 kV. The measurements were carried out for different dielectric barrier materials with the e values from 2 to 35. The dielectric barrier thickness was 0,9–1,8 mm. The study results have shown that the initial surface discharge ignition voltage depends essentially on the voltage pulse parameters, whereas the barrier characteristics have a weaker effect on this voltage. It has been determined that the discharge has different discharge zone length and different structure depending on the dielectric barrier properties and applied voltage parameters. The streamer zone sizes decrease with increasing the barrier material e value at the same voltage pulse steepness and increase with increasing the steepness for each barrier material. The data obtained for a wide range of external conditions can be used in numerical modeling of discharge.

A Comprehensive Review on C-3 Functionalization of β-Lactams

2019 ◽  
Vol 16 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Reshma Nagpal ◽  
Jitender Bhalla ◽  
Shamsher S. Bari
Keyword(s):  
Scientific Community ◽  
Organometallic Reagent ◽  
Reaction Conditions ◽  
Biological Potential ◽  
Wide Range ◽  
Economic Strategies ◽  
Synthetic Utility ◽  
Recent Advancement ◽  
Equivalent Method ◽  
Made In

Background:A lot of advancement has been made in the area of β-lactams in recent times. Most of the research is targeted towards the synthesis of novel β-lactams, their functionalization and exploring their biological potential. The C-3 functionalization of β-lactams has continued to attract considerable interest of the scientific community due to their utility as versatile intermediates in organic synthesis and their therapeutic applications. This has led to the significant increase in efforts towards developing efficient and economic strategies for C-3 functionalized β-lactams.Objective:The present review aims to highlight recent advancement made in C-3 functionalization of β-lactams.Conclusion:To summarize, functionalization of β-lactams at C-3 is an essential aspect of β-lactam chemistry in order to improve/modify its synthetic utility as well as biological potential. The C-3 carbocation equivalent method has emerged as an important and convenient strategy for C-3 functionalization of β-lactam heterocycles which provides a wide range of β-lactams viz. 3-alkylated β-lactams, 3-aryl/heteroarylated β-lactams, 3- alkoxylated β-lactams. On the other hand, base mediated functionalization of β-lactams via carbanion intermediate is another useful approach but their scope is limited by the requirement of stringent reaction conditions. In addition to this, organometallic reagent mediated α-alkylation of 3-halo/3-keto-β-lactams also emerged as interesting methods for the synthesis of functionalized β-lactams having good yields and diastereoselectivities.

scholarly journals Multiplexed Genetic Analysis Using an Expanded Genetic Alphabet

2004 ◽  
Vol 50 (11) ◽  
pp. 2019-2027 ◽  
Author(s):  
Scott C Johnson ◽  
David J Marshall ◽  
Gerda Harms ◽  
Christie M Miller ◽  
Christopher B Sherrill ◽  
...  
Keyword(s):  
Newborn Screening ◽  
Cftr Gene ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Genetic Tests ◽  
Wide Range ◽  
Additional Base ◽  
A Prospective Study ◽  
Cystic Fibrosis Transmembrane ◽  
Made In

Abstract Background: All states require some kind of testing for newborns, but the policies are far from standardized. In some states, newborn screening may include genetic tests for a wide range of targets, but the costs and complexities of the newer genetic tests inhibit expansion of newborn screening. We describe the development and technical evaluation of a multiplex platform that may foster increased newborn genetic screening. Methods: MultiCode® PLx involves three major steps: PCR, target-specific extension, and liquid chip decoding. Each step is performed in the same reaction vessel, and the test is completed in ∼3 h. For site-specific labeling and room-temperature decoding, we use an additional base pair constructed from isoguanosine and isocytidine. We used the method to test for mutations within the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The developed test was performed manually and by automated liquid handling. Initially, 225 samples with a range of genotypes were tested retrospectively with the method. A prospective study used samples from >400 newborns. Results: In the retrospective study, 99.1% of samples were correctly genotyped with no incorrect calls made. In the perspective study, 95% of the samples were correctly genotyped for all targets, and there were no incorrect calls. Conclusions: The unique genetic multiplexing platform was successfully able to test for 31 targets within the CFTR gene and provides accurate genotype assignments in a clinical setting.

scholarly journals LINEAR SYSTEMS ON IRREGULAR VARIETIES

2019 ◽  
Vol 19 (6) ◽  
pp. 2087-2125 ◽  
Author(s):  
Miguel Ángel Barja ◽  
Rita Pardini ◽  
Lidia Stoppino
Keyword(s):  
Continuous Function ◽  
Line Bundle ◽  
Linear Systems ◽  
Projective Variety ◽  
Geometrical Properties ◽  
Complex Projective Variety ◽  
Wide Range ◽  
Image Position ◽  
Irregular Varieties ◽  
Complex Projective

Let $X$ be a normal complex projective variety, $T\subseteq X$ a subvariety of dimension $m$ (possibly $T=X$) and $a:X\rightarrow A$ a morphism to an abelian variety such that $\text{Pic}^{0}(A)$ injects into $\text{Pic}^{0}(T)$; let $L$ be a line bundle on $X$ and $\unicode[STIX]{x1D6FC}\in \text{Pic}^{0}(A)$ a general element.We introduce two new ingredients for the study of linear systems on $X$. First of all, we show the existence of a factorization of the map $a$, called the eventual map of $L$ on $T$, which controls the behavior of the linear systems $|L\otimes \unicode[STIX]{x1D6FC}|_{|T}$, asymptotically with respect to the pullbacks to the connected étale covers $X^{(d)}\rightarrow X$ induced by the $d$-th multiplication map of $A$.Second, we define the so-called continuous rank function$x\mapsto h_{a}^{0}(X_{|T},L+xM)$, where $M$ is the pullback of an ample divisor of $A$. This function extends to a continuous function of $x\in \mathbb{R}$, which is differentiable except possibly at countably many points; when $X=T$ we compute the left derivative explicitly.As an application, we give quick short proofs of a wide range of new Clifford–Severi inequalities, i.e., geographical bounds of the form $$\begin{eqnarray}\displaystyle \text{vol}_{X|T}(L)\geqslant C(m)h_{a}^{0}(X_{|T},L), & & \displaystyle \nonumber\end{eqnarray}$$ where $C(m)={\mathcal{O}}(m!)$ depends on several geometrical properties of $X$, $L$ or $a$.

scholarly journals Dust Explosion Prevention and Mitigation, Status and Developments in Basic Knowledge and in Practical Application

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Rolf K. Eckhoff
Keyword(s):  
Process Design ◽  
Basic Knowledge ◽  
Industrial Plant ◽  
Practical Application ◽  
Process Industries ◽  
Wide Range ◽  
Firm Knowledge ◽  
Systematic Education ◽  
Training Of Personnel ◽  
Made In

Right from the early days of the process industries, continuous efforts have been made to develop and improve measures for prevention and mitigation of dust explosions in these industries. Nevertheless this hazard continues to threaten industries that manufacture, use and/or handle powders and dusts of a wide range of combustible materials. To improve methods for predicting explosion development in real industrial plant has been one major challenge. Hence, during the last years comprehensive numerical simulation codes, for addressing this problem, have been developed. Progress has also been made in other areas, for example, ignition source prevention. The importance of adopting inherently safer process design, by building on firm knowledge in powder science and technology, and of systematic education/training of personnel, is also emphasized.

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