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匹配条件: “Petru Daniel M?RAN” ,找到相关结果约430098条。
The Impact of the Economic Crisis on the Romanian Communities from the Province of Ciudad Real, Spain. The Villarrubia de los Ojos Case
Petru Daniel MRAN
Journal of Settlements and Spatial Planning , 2012,
Abstract: The consequences of the economic crisis that started in 2007 strongly affect the Spanish economy and increase the vulnerability of the immigrant population from Spain, in the context of the deepened deficiencies on the labor market and the changes in the migration policies from this country. The method of approaching the research involves the demographic and spatial analysis in Geographical Information Systems, at variable scales, starting from the national state level, with a focus on the Romanians’ immigration in the Province of Ciudad Real and the Villarrubia de los Ojos locality. The spatial analysis is performed based on statistical indicators such as: the structure on gender and age groups of the Romanian immigrants from the Region of Ciudad Real, the unemployment rate of the immigrants and of the Spanish as well, the dynamics in the number of companies and of labor contracts from the sectors involving immigrants, the correlation between the number of immigrants and structure of agricultural areas, the structure of the immigrant school population, etc. The decline of the real estate market, due to the global economic crisis, has generated, within the immigrants’ families, strategies of re-migration and re-orientation on the labor market. The Spanish migration policy increases the vulnerability of the Romanian communities from Spain by reintroducing restrictions on the labor market, for the Romanian workers, starting with 22nd of July 2011.
Petru M?NDRU
Geographia Napocensis , 2009,
Abstract: The evolution of the etnical and confessional structure of the population in the Some ul Mic valley between 1850 and 2002. The analysis of the ethnic and confessional structure of the population in the Some ul Mic Valley in these 152 years gives us the possibility to show the changes that occurred from this point of view, changes that were influenced by a series of factors (social, political, economical etc.), which individualized the ethnical and confessional situation in each stage in the aforementioned period. From this point of view, showing the situation from the beginning (1850) and the end (2002) shows the changes that occurred. Thus, the ethnic table shows that: there was a growth in the number of Romanians, from 39.6% in 1850 to 79.4% in 2002, a decrease in the Hungarians’ number from 41.9% in 1850 to 18.2% in 2002, a decrease in the number of Gypsies (Roma) from 4.2% in 1850 to 1.7% in 2002, a decrease in the number of Germans from 2.9% to 0.2%, and as for the other ethnic groups, there was a decrease from 11.4% in 1850 to 0.5% in 2002. The confessional structure of the population has a similar evolution. The main religions, according to the number of believers are as follows: the Orthodox had a percentage of 5.81 in 1850 and 70.22 in 2002, the Reformed were 26.28% in 1850 and 12.11% in 2002, the Greek Catholics were 34.42% in 1850 and 5.52% in 2002, the Roman-Catholics were 26.71% in 1850 and 5.12% in 2002. The other religions had a share of 6.78% in 1850 and 7.03% in 2002. The evolution of the two structures of the Valley’s population shows, in 2002, an autochthonous population which is well-consolidated, from an ethnic, as well as confessional point of view.
A Simple Method to Increase the Amount of Energy Produced by the Photovoltaic Panels
Daniel Tudor Cotfas,Petru Adrian Cotfas
International Journal of Photoenergy , 2014, DOI: 10.1155/2014/901581
Abstract: The photovoltaic energy can become competitive by the conjugate effort of the researchers and manufacturers. Increasing the amount of electricity supplied by photovoltaic panels is a challenge. The paper briefly presents some methods which can lead to achieving this goal. A simple method to increase the quantity of the electrical energy delivered by the photovoltaic panels is also presented in this paper alongside the experimental setup and the software created in LabVIEW for monitoring the output of the panels. 1. Introduction The importance of renewable energy as a major source of energy for the entire world gradually grew, alongside the conventional energy sources. Due to the development of some countries with large populations such as China, India, and Brazil the energy requirements grew exponentially. The solutions for these requirements can be found in the exploitations of fossil fuels, leading to pollution increase and amplification of greenhouse effect and, as an alternative, there is the use of renewable energy and increasing its efficiency. The development of the renewable energy domain of the last years can also be explained by the aid and involvement of the politics. Countries such as USA, Canada, China, India, and European Union had created the legal frame for support using the subsidies, feed-in-tariff, fiscal instruments, creating the trading of green certificates, and so forth [1, 2]. Most of the countries have a declared goal for the renewable energy. California, state of USA, has an ambitious target—33% of the electricity must be produced from the renewable energy until 2020 [2, 3]. The fixed target is that until 2020 in the European Union 20% of the total energy must be obtained from renewable energy [4]. The members of the European Union have different targets; for example, Romania must obtain 24% of the total energy from renewable sources [2, 4]. Also, Japan has a high target for renewable energy production; this is 25%–35% from the total energy. China has 15% until 2020 and Australia has at least 20% of the electricity [2, 5, 6]. The photovoltaic energy becomes one of the most important types of renewable energy because the sun energy is free, there is an updated technology of using the silicon in electronics and this is easily transferrable to the manufacturing of solar cells, new types of solar cells and materials are being developed due to competiveness and the competition between researchers, and last, but not least, because of the political and economical factors, by the environmental rules imposed and by investment. Thus a
The Aluminum and Bromine Reaction Revisited: On the Hazard during Waste Disposal
VM Petru evski, M Stojanovska
African Journal of Chemical Education , 2011,
Abstract: A brief explanation for the absence of reaction between metallic sodium and liquid bromine is offered. A safer variant is proposed for performing the well-known demonstration of aluminum and bromine. An explanation for the increasing induction period for the reaction is given. A serious hazard exists during the disposal of the waste (AlBr3 dissolved in excess bromine), unless the instructor is familiar with the properties of the products. Attention is paid to this hazard and a possible way for minimizing the risk in waste disposal is pointed out.
Density in $W^{s,p}(Ω; N)$
Ha?m Brezis,Petru Mironescu
Mathematics , 2015,
Abstract: Let $\Omega$ be a smooth bounded domain in ${\mathbb R}^n$, $0\textless{}s\textless{}\infty$ and $1\le p\textless{}\infty$. We prove that $C^\infty(\overline\Omega\, ; {\mathbb S}^1)$ is dense in $W^{s,p}(\Omega ; {\mathbb S}^1)$ except when $1\le sp\textless{}2$ and $n\ge 2$. The main ingredient is a new approximation method for $W^{s,p}$-maps when $s\textless{}1$. With $0\textless{}s\textless{}1$, $1\le p\textless{}\infty$ and $sp\textless{}n$, $\Omega$ a ball, and $N$ a general compact connected manifold, we prove that $C^\infty(\overline\Omega \, ; N)$ is dense in $W^{s,p}(\Omega \, ; N)$ if and only if $\pi\_{[sp]}(N)=0$. This supplements analogous results obtained by Bethuel when $s=1$, and by Bousquet, Ponce and Van Schaftingen when $s=2,3,\ldots$ [General domains $\Omega$ have been treated by Hang and Lin when $s=1$; our approach allows to extend their result to $s\textless{}1$.] The case where $s\textgreater{}1$, $s\not\in{\mathbb N}$, is still open.
Stabilizing mutation of CTNNB1/beta-catenin and protein accumulation analyzed in a large series of parathyroid tumors of Swedish patients
Peyman Bj?rklund, Daniel Lindberg, G?ran ?kerstr?m, Gunnar Westin
Molecular Cancer , 2008, DOI: 10.1186/1476-4598-7-53
Abstract: The mutation S37A (TCT > GCT) was detected by direct DNA sequencing of PCR fragments in 6 out of 104 sporadic parathyroid adenomas (5.8%). Taking our previous study into account, a total of 9 out of 124 (7.3%) adenomas displayed the same mutation. The mutations were homozygous by DNA sequencing, restriction enzyme cleavage, and gene copy number determination using the GeneChip 500 K Mapping Array Set. All tumors analyzed by immunohistochemistry, including those with mutation, displayed aberrant β-catenin accumulation. Western blotting revealed a slightly higher expression level of β-catenin and nonphosphorylated active β-catenin in tumors with mutation compared to those without. Presence of the mutation was not related to distinct clinical characteristics.Aberrant accumulation of β-catenin is very common in parathyroid tumors, and is caused by stabilizing homozygous mutation in 7.3% of Swedish pHPT patients.Parathyroid disease with hypersecretion of parathyroid hormone and generally also hypercalcemia occurs in primary hyperparathyroidism (pHPT), due to growth regulatory disturbance in one or several parathyroid glands. Activation of CCND1 oncogene expression or inactivation of the MEN1 tumor suppressor gene contributes to deregulated growth control in a fraction of sporadic parathyroid adenomas [1-4].Activation of the Wnt/β-catenin signaling pathway by aberrant accumulation of stabilized β-catenin is involved in the development of many neoplasms. β-catenin accumulation is typically caused by mutations in components of the signaling pathway, such as APC, Axin, β-Trcp, and WTX, or results from secondary events. In addition, protein stabilizing mutations in the glycogen synthase kinase 3β phosphorylation sites of β-catenin (Ser-33, Ser-37, Thr-41, Ser-45) occur with varying frequency in several neoplasms [5-9].We recently reported activation of the Wnt/β-catenin signaling pathway by aberrant accumulation of β-catenin in parathyroid adenomas from patients with pHPT [10
On Serial Symmetric Exchanges of Matroid Bases
Daniel Kotlar,Ran Ziv
Mathematics , 2011,
Abstract: We study some properties of a serial (i.e. one-by-one) symmetric exchange of elements of two disjoint bases of a matroid. We show that any two elements of one base have a serial symmetric exchange with some two elements of the other base. As a result, we obtain that any two disjoint bases in a matroid of rank 4 have a full serial symmetric exchange.
A matroidal generalization of results of Drisko and Chappell
Daniel Kotlar,Ran Ziv
Mathematics , 2014,
Abstract: Let $M$ and $N$ be two matroids on the same ground set. We generalize results of Drisko and Chapell by showing that any $2n-1$ sets of size $n$ in $M \cap N$ have a rainbow set of size $n$ in $M \cap N$.
Large matchings in bipartite graphs have a rainbow matching
Daniel Kotlar,Ran Ziv
Mathematics , 2013,
Abstract: Let $g(n)$ be the least number such that every collection of $n$ matchings, each of size at least $g(n)$, in a bipartite graph, has a full rainbow matching. Aharoni and Berger \cite{AhBer} conjectured that $g(n)=n+1$ for every $n>1$. This generalizes famous conjectures of Ryser, Brualdi and Stein. Recently, Aharoni, Charbit and Howard \cite{ACH} proved that $g(n)\le\lfloor\frac{7}{4}n\rfloor$. We prove that $g(n)\le\lfloor\frac{5}{3} n\rfloor$.
On the Length of a Partial Independent Transversal in a Matroidal Latin Square
Daniel Kotlar,Ran Ziv
Mathematics , 2012,
Abstract: We suggest and explore a matroidal version of the Brualdi - Ryser conjecture about Latin squares. We prove that any $n\times n$ matrix, whose rows and columns are bases of a matroid, has an independent partial transversal of length $\lceil2n/3\rceil$. We show that for any $n$, there exists such a matrix with a maximal independent partial transversal of length at most $n-1$.

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