Hydrophobic Coatings for Corrosion Control of Aluminum Heat Exchangers

The production of thin films (nanocoatings) is a technological field with many applications to elaborate materials with new properties to be used as corrosion protection of traditional metals. Hydrophobicity is an example of such properties. In this chapter, an example of two hydrophobic corrosion coatings for possible use over aluminum heat exchanger geothermal power plants is discussed. Material substrate preparation, synthesis of hydrophobic sol‐gel nanocoating, characterization, and electrochemical evaluation as a function of time of immersion, which are compared to another commercial fluorinated compound, are presented. Good corrosion protection was found for both hydrophobic coatings for possible application in geothermal heat exchangers

Mexican Validation of the MOS Questionnaire on Perceived Social Support in the Context of the COVID-19 Pandemic

Es un artículo científicoThe COVID-19 pandemic has had a very negative impact on people’s overall mental health and psychosocial well-being, but the study of available social support to cope with such an adverse situation has received hardly any attention. Objective: To examine the psychometric properties of the MOS Perceived Social Support Questionnaire among the Mexican population in the context of the COVID-19 pandemic. Method: Non-experimental cross-sectional study. A sociodemographic questionnaire and the Medical Outcomes Study were applied in a non-probabilistic sample. A total of 898 people from different regions in Mexico, 258 males and 640 females, participated in the study in the context of the COVID-19 pandemic. Results: The analysis yielded a bi-factor model with two factors, Emotional/informational support and Tangible support, with satisfactory goodness of fit indices. Reliability was adequate with a high hierarchical omega coefficient, as well as in the factors. Likewise, the H coefficient was adequate in the general factor and its dimensions. Conclusions: Results showed that the scale is a valid and reliable measure of perceived social support among the Mexican population

Salud mental en población mexicana por COVID-19

Es un artículo científicoThe COVID-19 pandemic has had a significant negative impact on the mental health and psychosocial well-being of the general population, but little attention has been paid to the social support available to people to cope with such adverse conditions. Objective. To examine the psychometric properties of the MOS Perceived Social Support Questionnaire in the Mexican population in the context of the COVID-19 pandemic. Method. Non-experimental cross-sectional study. A sociodemographic questionnaire and the Medical Outcomes Study (MOS) were applied in a non-probabilistic sample. A total of 898 people from different regions of Mexico (Mage = 34.85, SD = 11.37, Females = 640, Males = 258) participated in the study. Results. The analysis yielded a bifactor model with two factors (F1. Emotional/informational support, F2. Tangible support) with satisfactory goodness of fit indices (χ2 = 486.36; df = 88; p = .000; RMSEA = .071 [IC90% .065 – .077]; SRMR = .02; CFI =.99; TLI =.99). Reliability was adequate with a high hierarchical omega coefficient (.95), as well as on the factors (F1 ωhs = .03, F2 ωhs = .28). Likewise, the H coefficient was adequate in the general factor and its dimensions (HHG = 98; Hhs = .28; Hhs = .56). Discussion and conclusion. Results showed that the scale is a valid and reliable measure of perceived social support in the Mexican population

Caracteristicas reproductivas de ovejas Pelibuey sincronizadas e inducidas a la pubertad

El objetivo del experimento fue analizar las características reproductivas de ovejas Pelibuey sincronizadas (T1: n = 7) e inducidas a la pubertad (T2: n = 7). Las ovejas del T1 se presincronizaron, siete días después se aplicó a todas las ovejas FGA intravaginal durante 12 d y dos días antes de retirar el FGA se aplicó eCG. La incidencia de estro fue de 100 % en T1 y T2. El inicio del estro no fue diferente (P>0.05) con valores 21.4 ± 2.2 h y 24.2 ± 3.2 h para T1 y T2. La duración del estro fue de 60.5 ± 6.6 y 41.3 ± 3.6 para T1 y T2 (P<0.05). El inicio, duración y amplitud del pulso preovulatorio de LH no mostró diferencias con valores de 24.5 ± 1.7 y 24.2 ± 4.7 h, 13.4 ± 1.2 y 14.0 ± 0.6 h, 18.1 ± 2.7 y 21.3 ± 3.1 ng mL-1 para T1 y T2 respectivamente. La tasa de gestación no fue diferente con 100 y 85.71 % para T1 y T2. La tasa ovulatoria y prolificidad fue diferente (P<0.05) con valores de 4.4 ± 1.2 y 2.7 ± 0.4 y 2.5 ± 0.2 y 1.4 ± 0.4, para el T1 y T2 respectivamente. Se concluyó que el uso de FGA y eCG en ovejas Pelibuey es recomendable para inducir la pubertad, ya que las características reproductivas analizadas son aceptables, su implementación puede ser factible en programas de inseminación a tiempo fijo

Aptitud combinatoria y heterosis en híbridos de líneas endogámicas de maíz/Combining ability and heterosis in hybrids from inbred lines corn

El trabajo se realizó en dos etapas, en la primera se formaron las cruzas en el campo experimental de la Universidad Autónoma Agraria Antonio Narro Unidad Laguna (UAAAN-UL), y en la segunda la evaluación en el campo experimental de la UAAAN-UL en los ciclos agrícola primavera y verano, y en el ejido Niágara, en el municipio de Aguascalientes, Aguascalientes, en primavera. El material genético fueron 17 líneas endogámicas, cuatro de la UAAAN-UL, dos del INIFAP y 11 del CIMMYT. El objetivo fue estimar la aptitud combinatoria general (ACG) de las líneas, la aptitud combinatoria especíca (ACE) y cuanticar los efectos genéticos y la heterosis de las cruzas. Para la ACG sobresalieron las líneas macho LAN-388P, LB-32 y LB-40, y las líneas hembras CML-319, CML-318 y CML-278; para la ACE los mayores valores lo tuvieron las cruzas LAN-123xCML-278 (3.28 t ha−1 ), LAN-123xCML-318 (1.9 t ha−1 ), LB-40xCML-319 (1.7 t ha−1 ) y LAN-388PxCML-264 (1.52 t ha−1 ). Mientras que el mayor rendimiento de grano, lo tuvieron las cruzas LB-40xCML-319 (14.49 t ha−1 ), LB-32xCML-319 (14.17 t ha−1 ), LAN-388PxCML-264 (13.68 t ha−1 ), LAN-123xCML-278 (13.55 t ha−1 ) y LAN-388PxCML-278 (13.44 t ha−1 ). La varianza de dominancia superó a la varianza aditiva en rendimiento de grano (RG) y en los principales componentes del rendimiento. Se encontraron efectos positivos de heterosis para rendimiento de grano con respecto al progenitor superior en las cruzas LB-40xCML-319 y LB-32 x CML-31

Observation of the Rare Decay of the η Meson to Four Muons

A search for the rare η→μ+μ−μ+μ− double-Dalitz decay is performed using a sample of proton-proton collisions, collected by the CMS experiment at the CERN LHC with high-rate muon triggers during 2017 and 2018 and corresponding to an integrated luminosity of 101  fb−1. A signal having a statistical significance well in excess of 5 standard deviations is observed. Using the η→μ+μ− decay as normalization, the branching fraction B(η→μ+μ−μ+μ−)=[5.0±0.8(stat)±0.7(syst)±0.7(B2μ)]×10−9 is measured, where the last term is the uncertainty in the normalization channel branching fraction. This work achieves an improved precision of over 5 orders of magnitude compared to previous results, leading to the first measurement of this branching fraction, which is found to agree with theoretical predictions

Performance of the local reconstruction algorithms for the CMS hadron calorimeter with Run 2 data

A description is presented of the algorithms used to reconstruct energy deposited in the CMS hadron calorimeter during Run 2 (2015–2018) of the LHC. During Run 2, the characteristic bunch-crossing spacing for proton-proton collisions was 25 ns, which resulted in overlapping signals from adjacent crossings. The energy corresponding to a particular bunch crossing of interest is estimated using the known pulse shapes of energy depositions in the calorimeter, which are measured as functions of both energy and time. A variety of algorithms were developed to mitigate the effects of adjacent bunch crossings on local energy reconstruction in the hadron calorimeter in Run 2, and their performance is compared

Search for new physics in multijet events with at least one photon and large missing transverse momentum in proton-proton collisions at 13 TeV

A search for new physics in final states consisting of at least one photon, multiple jets, and large missing transverse momentum is presented, using proton-proton collision events at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 137 fb−1, recorded by the CMS experiment at the CERN LHC from 2016 to 2018. The events are divided into mutually exclusive bins characterized by the missing transverse momentum, the number of jets, the number of b-tagged jets, and jets consistent with the presence of hadronically decaying W, Z, or Higgs bosons. The observed data are found to be consistent with the prediction from standard model processes. The results are interpreted in the context of simplified models of pair production of supersymmetric particles via strong and electroweak interactions. Depending on the details of the signal models, gluinos and squarks of masses up to 2.35 and 1.43 TeV, respectively, and electroweakinos of masses up to 1.23 TeV are excluded at 95% confidence level

First measurement of the top quark pair production cross section in proton-proton collisions at s \sqrt{s} = 13.6 TeV

The first measurement of the top quark pair (tt¯) production cross section in proton-proton collisions at s√ = 13.6 TeV is presented. Data recorded with the CMS detector at the CERN LHC in Summer 2022, corresponding to an integrated luminosity of 1.21 fb−1, are analyzed. Events are selected with one or two charged leptons (electrons or muons) and additional jets. A maximum likelihood fit is performed in event categories defined by the number and flavors of the leptons, the number of jets, and the number of jets identified as originating from b quarks. An inclusive tt¯ production cross section of 881 ± 23 (stat + syst) ± 20 (lumi) pb is measured, in agreement with the standard model prediction of 924+32−40 pb

Measurements of inclusive and differential cross sections for the Higgs boson production and decay to four-leptons in proton-proton collisions at s \sqrt{s} = 13 TeV

Measurements of the inclusive and differential fiducial cross sections for the Higgs boson production in the H → ZZ → 4ℓ (ℓ = e, μ) decay channel are presented. The results are obtained from the analysis of proton-proton collision data recorded by the CMS experiment at the CERN LHC at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb−1. The measured inclusive fiducial cross section is 2.73 ± 0.26 fb, in agreement with the standard model expectation of 2.86 ± 0.1 fb. Differential cross sections are measured as a function of several kinematic observables sensitive to the Higgs boson production and decay to four leptons. A set of double-differential measurements is also performed, yielding a comprehensive characterization of the four leptons final state. Constraints on the Higgs boson trilinear coupling and on the bottom and charm quark coupling modifiers are derived from its transverse momentum distribution. All results are consistent with theoretical predictions from the standard model