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Effect of the Substitution of Sand by Rubber of Waste Tires on the Mechanical Properties of Hydraulic Concrete and Exposure to Gamma Radiation

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Journal of Minerals and Materials Characterization and Engineering 2021年第3期9卷 245-256页

作者： Jesús M. Colín de la Cruz Carmen Gabriela Guzmán Fermín Castillo Mejía Benjamin Leal Acevedo Osvaldo Flores Cedillo Isabel Gamboa de Buen Arturo Molina Ocampo horacio martínez valencia Facultad de Ciencias Químicas e Ingeniería Universidad Autónoma del Estado de Morelos Cuernavaca México Laboratorio de Espectroscopia Instituto de Ciencias Físicas Universidad Nacional Autónoma de México Cuernavaca México Instituto de Ciencias Nucleares Universidad Nacional Autónoma de México México City México Centro de Investigación en Ingeniería y Ciencias Aplicadas UAEM Cuernavaca México

For a long time and until now, rubber is the most used material for the manufacture of tires for motor vehicles. Unfortunately, once the tire meets its life cycle, the remaining rubber cannot be recycled, so the tires are discarded in collection centers and often in clandestine dumps. This represents a serious environmental problem because, in one case, these waste tires become breeding grounds for insects and wildlife that is harmful to humans. In the second case, the tires are burned, releasing highly damaging gases into the atmosphere. On the other hand, concrete is worldwide the construction material par excellence. It is basically composed of cement, gravel and sand. Mixing these three components in different proportions, their mechanical strength in compression can be increased. However, due to its fragile nature, concrete, once a crack is formed, it rapidly advances by fragmenting the material and producing its rapid collapse. In the present work, in order contribute to the care of the environment as well as to modify the fracture mode of the concrete, rubber particles obtained from waste tires were used as sand substitute in hydraulic concrete. In addition, rubber modified samples concrete were lately exposed to 70 kGy of gamma radiation in order to study the effects of this radiation on the mechanical deformation of concrete. The results showed a decrease in the mechanical properties of the concrete with rubber particles with respect to the traditional concrete itself. However, such decreases were offset by the fact that samples with rubber addition do not collapses as fast as the free rubber samples. The acquired data pave the way for research with great benefits, such as the use of recycled tires in concrete for its fracture mode modification in a beneficial way, as well as a possible decrease in the cost of concrete.

关键词： Hydraulic Concrete Scrap Tire Rubber Strength Gamma Radiation Mechanical Properties

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Metal-modulated epitaxy of Mg-doped Al_(0.80)In_(0.20)N-based layer for application as the electron blocking layer in deep ultraviolet light-emitting diodes

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Journal of Semiconductors 2024年第5期45卷 80-89页

作者： horacio Irán Solís-Cisneros Carlos Alberto Hernández-Gutiérrez Enrique Campos-González Máximo López-López Optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico Departamento de Física Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico Departamento de Física Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of p-AlInN layers doped with Mg by plasma-assisted molecular beam epitaxy(PAMBE).AlInN was grown with an Al molar fraction of 0.80 by metal-modulated epitaxy(MME)with a thickness of 180 nm on Si(111)substrates using AlN as buffer *** substrate temperatures were used to enhance the incorporation of indium atoms into the alloy without clustering,as confirmed by X-ray diffraction(XRD).Cathodoluminescence measurements revealed ultraviolet(UV)range ***,Hall effect measurements indicated a maximum hole mobility of 146 cm^(2)/(V∙s),corresponding to a free hole concentration of 1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPS)estimating the alloy composition and extracting the Fermi level by valence band ***-doped AlInN layers were studied for use as the electron-blocking layer(EBL)in LED *** varied the Al composition in the EBL from 0.84 to 0.96 molar fraction to assess its theoretical effects on electroluminescence,carrier concentration,and electric field,using SILVACO *** results from this study highlight the importance and capability of producing high-quality Mg-doped p-AlInN layers through *** simulations suggest that an Al content of 0.86 is optimal for achieving desired outcomes in electroluminescence,carrier concentration,and electric field.

关键词： metal-modulated epitaxy AlInN DUV-LED EBL simulation

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Piezoelectric constant temperature dependence in strained [111]-oriented zinc-blende MQW-SOAs

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Chinese Optics Letters 2023年第9期21卷 107-112页

作者： horacio Soto-Ortiz Gerson Torres-Miranda Applied Physics Division Center for Scientific Research and Higher Education of Ensenada

Here,we present a study of the effective piezoelectric constant(e_(14_(e)))temperature dependence in strained[111]-oriented zinc-blende quantum wells(QWs)embedded within a semiconductor optical amplifier(SOA).We determined e_(14_(e)) using a method that was insensitive to the segregation phenomenon and to the temperature dependence of the bandgap energy,which required neither fitting parameters nor temperature-dependent expressions for energy and out-of-plane effective masses of electrons and heavy *** e_(14_(e))=−0.0534±0.0040 C·m^(−2) at 23°C was obtained for an SOA with 1.2 nm[111]-oriented strained In0.687Ga0.313As/In0.807Ga0.193As0.304P0.696 *** previously published research,where e_(14_(e)) magnitude increased as temperature rised,we extracted an e_(14_(e)) magnitude that decreased as temperature increased.

关键词： piezoelectric constant pyroelectric effect quantum-confined Stark effect excitons semiconductor optical amplifiers zinc-blende quantum wells

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Machine learning assisted design of shape-programmable 3D kirigami metamaterials

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npj Computational Materials 2022年第1期8卷 1817-1828页

作者： Nicolas A.Alderete Nibir Pathak horacio D.Espinosa Theoretical and Applied Mechanics Northwestern UniversityEvanstonIL60208USA Department of Mechanical Engineering Northwestern UniversityEvanstonIL60208USA

Kirigami-engineering has become an avenue for realizing multifunctional metamaterials that tap into the instability landscape of planar surfaces embedded with ***,it has been shown that two-dimensional Kirigami motifs can unfurl a rich space of out-of-plane deformations,which are programmable and controllable across spatial *** Kirigami’s versatility,arriving at a cut layout that yields the desired functionality remains a ***,we introduce a comprehensive machine learning framework to shed light on the Kirigami design space and to rationally guide the design and control of Kirigami-based materials from the meta-atom to the metamaterial *** employ a combination of clustering,tandem neural networks,and symbolic regression analyses to obtain Kirigami that fulfills specific design constraints and inform on their control and *** systematic approach is experimentally demonstrated by examining a variety of applications at different hierarchical levels,effectively providing a tool for the discovery of shape-shifting Kirigami metamaterials.

关键词： shape hierarchical shifting

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Clinical relevance of stem cells in lung cancer

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World Journal of Stem Cells 2023年第6期15卷 576-587页

作者： horacio Eduardo Romeo María Laura Barreiro Arcos School of Engineering and Agrarian Sciences Pontifical Catholic University of ArgentinaInstitute of Biomedical Research(BIOMED-UCA-CONICET)CABA C1107AAZBuenos AiresArgentina

Lung cancer is the major cause of cancer-related deaths worldwide,it has one of the lowest 5-year survival rate,mainly because it is diagnosed in the late stage of the *** cancer is classified into two groups,small cell lung cancer(SCLC)and non-SCLC(NSCLC).In turn,NSCLC is categorized into three distinct cell subtypes:Adenocarcinoma,squamous cell carcinoma,and large cell *** is the most common lung cancer,accounting for 85%of all lung *** for lung cancer is linked to the cell type and stage of the disease,involving chemotherapy,radiation therapy,and *** improvements in therapeutic treatments,lung cancer patients show high rates of recurrence,metastasis,and resistance to *** stem cells(SCs)are undifferentiated cells capable of self-renewal and proliferation,are resistant to chemotherapy and radiotherapy and,due to their properties,could be involved in the development and progression of lung *** presence of SCs in the lung tissue could be the reason why lung cancer is difficult to *** identification of lung cancer stem cells biomarkers is of interest for precision medicine using new therapeutic agents directed against these cell *** this review,we present the current knowledge on lung SCs and discuss their functional role in the initiation and progression of lung cancer,as well as their role in tumor resistance to chemotherapy.

关键词： Lung cancer Cancer stem cells Biomarkers Chemoresistance

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Numerical simulation of sedimentation processes in reservoirs as a function of outlet location

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International Journal of Sediment Research 2009年第3期24卷 339-351页

作者： horacio TONIOLO Civil and Environmental Engineering Department University of Alaska Fairbanks

This paper builds on a recently published one-dimensional moving-boundary model of the coevolution of topset, foreset and bottomset in a reservoir that captures the dynamics of the internal muddy pond typical to reservoirs. This model was modified to account for different outlet locations at the reservoir’s downstream end. This model considers a river carrying two sustained phases of sediments: coarse (sand) and fine (mud). The coarse phase deposits in the topset and delta foreset, while the fine phase forms a dilute suspension of wash load in the river. As the river enters the reservoir, the muddy water plunges on the foreset to form a Froude-supercritical (purely depositional) turbidity current. This turbidity current emplaces the bottomset. The modified numerical model was tested against five laboratory experiments previously reported by the author. The model successfully locates the muddy-water/clear-water interface. In addition, modeled and measured bed deposits are in good agreement. Results clearly indicate that the location of the internal hydraulic jump plays a key role in the final bed deposit.

关键词： Numerical model Delta Ponded turbidity currents Outlet location Reservoirs

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The Gaps between Primes

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Advances in Pure Mathematics 2022年第12期12卷 757-771页

作者： Pal Doroszlai horacio Keller Independent Researcher Kékkút Hungary

The union of the straight and—of the over a point of reflection—reflected union of the series of the arithmetic progression of primes results the double density of occupation of integer positions by multiples of the primes. The remaining free positions represent diads of equidistant primes to the point of reflection: in case the point of reflection is an even number, they satisfy Goldbach’s conjecture. Further, it allows to prove, that the number of twin primes is unlimited. The number of all greater gaps as two between primes has well defined lower limit functions as well: it is evaluated with the local density of diads, multiplied with the total of the density of no-primes of all positions over the distance between the components of the diads (the size of the gaps). The infinity of these lower limit functions proves the infinity of the number of gaps of any size between primes. The connection of the infinite number of diads to the infinity of the number of gaps of any size is the aim of the paper.

关键词： Twin Primes Prime Gaps Goldbach’s Conjecture

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The Symmetric Series of Multiples of Primes

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Advances in Pure Mathematics 2022年第3期12卷 160-177页

作者： Pal Doroszlai horacio Keller Independent Researcher Kékkut Hungary

The union of the straight and over the point of reflection—reflected series of the arithmetic progression of primes results in the double density of occupation of integer positions. It is shown that the number of free positions left by the double density of occupation has a lower limit function, which is growing to infinity. The free positions represent equidistant primes to the point of reflection: in case the point of reflection is an even number, they satisfy Goldbach’s conjecture. The double density allows proving as well that at any distance from the origin large enough—the distance between primes is smaller, than the square root of the distance to the origin. Therefore, the series of primes represent a continuum and may be integrated. Furthermore, it allows proving that the largest gap between primes is growing to infinity with the distance and that the number of any two primes, with a given even number as the distance between them, is unlimited. Thus, the number of twin primes is unlimited as well.

关键词： Twin Primes Prime Gaps Goldbach’s Conjecture

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The Primes and Their Subsets as Continuum like the Integers

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Advances in Pure Mathematics 2023年第12期13卷 733-750页

作者： Pal Doroszlai horacio Keller Independent Researcher Kékkut Hungary

The present paper gives the proof of the set of primes as a continuum. It starts with the density of the primes, and shortly recapitulates the prime-number-formula and the complete-prime-number-formula. Reflecting the series of the primes over any prime gives the double density of occupation of integer positions by the union of the series of multiples of the primes. The remaining free positions render it possible to prove Goldbach’s conjecture and the set of primes as a continuum. The theoretical evaluation is followed in annexes by numerical evaluation, demonstrating the theoretical results. The numerical evaluation results in different constants and relations, which represent inherent properties of the set of primes.

关键词： Prime-Number-Formula Complete-Prime-Number-Formula Goldbach’s Conjecture Primes as Continuum

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The Integral of the Inverse of the Primes

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Advances in Pure Mathematics 2023年第5期13卷 250-266页

作者： Pal Doroszlai horacio Keller Independent Researcher Kékkut Hungary

The present paper gives the proof of the set of primes as continuum and evaluates the analytical formula for the integral of the inverse of the primes over the distance. First it starts with the density of the primes, shortly recapitulates the prime-number-formula and the complete-prime-number-formula, the proof of the set of primes as continuum. The theoretical evaluation is followed in annexes by numerical evaluation of the theoretical results and of different constants, which represent inherent properties of the set of primes.

关键词： Density of Primes Prime-Number-Formula Complete-Prime-Number-Formula Goldbach’s Conjecture Twin Primes K-Tuples of Primes Primes as Continuum

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