bluuebunny/crossref_metadata_2025 huggingface dataset:
A Close Look at the Measurement of Shock Data: Lessons Learned
Authors: Hollowell Bill , Smith Strether , Hansen Jim
Published: November 2020

Pyroshock testing and analysis is one of the most difficult regimens in the field of structural dynamics. The harsh and often-unpredictable environment has caused relatively poor behavior of the measurements systems used, often for reasons that were not well-understood. This paper reports on a study that was performed with the goal of better understanding the problem areas and development of methods for improving results. Specific areas addressed include: characterization of the broadband response and evaluation of its effects on standard measurement systems, transducer mounting and cabling techniques, measurement of inplane motion, and the problem of justifying/normalizing the results obtained by different data acquisition systems.
Flow Features to Control Thermally Induced Convection in a Vertical Laminar Flow Cleanroom
Authors: Nishioka Toshiaki
Published: November 2020

This paper presents results of a flow simulation study of convection heat currents above a heat source in a vertical laminar flow (VLF) cleanroom as determined both experimentally and computationally. Typical clcanroom operations have numerous pieces of equipment that generate heat— thus the importanec of this study. The experiment was carried out in a full-scale mockup of a cleanroom. Temperature distributions above an electrical hot plate were measured for 12 airflow velocities and four heat source levels. The results showed that when the mean downward airflow velocity was 0.20 m/s or greater, the plume of heated air was completely suppressed and rose only 30 cm above the heat source. The relation between the convection current zone and the Richardson number was determined.

Computer models simulating the turbulent incompressible fluid flow in a Cartesian coordinate system were applid to analyze the three-dimensional heat currents inside the VLF cleanroom and to prediet the temperature and velocity distributions. The velocity distributions clearly indicated the magnitude of the area within which the heat current disturbed the vertical flow. Comparisons between the experimental findings and the calculated results provided significant information on how to apply the computer simulation to a practical design.
Latex Sphere Retention by Microporous Membranes in Liquid Filtration
Authors: Lee Jae-Keun , Liu Benjamin , Rubow Kenneth
Published: November 2020

An experimental study of particulate matter retention by microporous membranes during liquid filtration has been conducted using 0.1, 0.22, 0.45, and 0.65-μm-rated hydrophilic and hydrophobic membrane filters. Retention measurements have been made with polystyrene latex spheres using an automated filter test system and a laser particle counter to measure the upstream and downstream particle concentration.

Particle filtration during loading tests was found to begin with a sieving dominant regime followed by a transition regime and a cake filtration regime as particles accumulate inside the filter pores and on the filter surface. For latex sphere sizes equal to the nominal pore size of the filter, the initial filter efficiencies ranged from 97 to 99.9 percent. Complete retention (>99.9999999 percent) was achieved for a range of particle sizes two to three times the rated pore sizes of the filter. With the addition of a surfactant to the liquid, the retention was found to be lowered as a result of enhanced particle passage through the filter due to modified surface adsorption and steric stabilization. It was found that particle retention by sieving with the addition of surfactant provided the "worst-case" test for filter performance.
Contamination Control of Polysilicon Gates in a Vertical Reactor Cluster Tool
Authors: Werkhoven C. , Granneman E. , Lindow E. , de Blank R. , Verhavcrbeke S. , Heyns M.
Published: November 2020

This paper demonstrates that defect control is greatly improved when using the protected environment of a vertical reactor cluster tool comprising a preclean station. The cluster tool investigated combines the established process stability of vertical reactors with new capabilities as native oxide removal, ultraclean wafer transport, and reactors shielded from enviromental contamination. An adequate combination of clean gas usage and leak tightness makes it possible to apply HF vapor etching effectively in order to control the properties of the silicon-silicon oxide interface. For different precleaning conditions, interface and bulk contamination was measured, the sources identified, and the effect of improvements monitored. To this end, several electrical parameters were determined, including the analysis of Qhd and Ehd. Quantitative TXRF and SIMS techniques were used to correlate the results with metallic and organic contamination.
Process Improvement Using In-Situ Particle Detection
Authors: Wu Jin , Miller James , Tinker Mark
Published: November 2020

An engineering criterion is derived to determine when the particle level detected in exhaust flow can be treated as a representiative measure of particle concentration in the reactor. It is established when gravitation sedimentation is the dominant phenomenon affecting particle deposition and when the particle distribution in the reactor is well-mixed. An example of using this technology to improve a plasma-en-hanced chemical vapor deposition process is presented.
Role of Failure-Mechanism Identification in Accelerated Testing
Authors: Hu J. , Barker D. , Dasgupta A. , Arora A.
Published: November 2020

Accelerated life testing techniques provide a short-cut method to investigate the reliability of electronic devices with respect to certain dominant failure mechanisms that occur under normal operating conditions. However, accelerated tests have often been conducted without knowledge of the failure mechanisms and without ensuring that the test accelerated the same mechanism as that obscrved under normal operating conditions. This paper summarizes common failure mechanisms in electronic devices and packages and investigates possible failure mechanism shifting during accelerated testing.
Application of a Commercial Nonvolatile Residue Monitor to Measure Purity of Solvents and Surface Cleanliness
Authors: Hill Elizabeth , Ensor David , Lawless Phil , Donovan Robert
Published: November 2020

A nonvolatile residue monitor was used to determine the cleanliness levels of deionized water, pure solvents, and solutios used to measure surface cleanliness by extraction. The measurement is rapid, repeatable, and simple to perform. With the use of calibration curves, it provides a quantitative measure of nonvolatile residue (NVR). This method can be used to replace other procedures that require evaporation of large volumes of solvent, saving time and reducing solvent emissions. The detection limit is in the nanogram range for many common nonvolatile residues.
Scanning High-Efficiency Air Filters for Leaks Using Particle Counting Methods
Authors: McDonald Bruce
Published: November 2020

High-efficiency particulate air (HEPA) filters and ultra low penetration air (ULPA) filters such as those used in cleanrooms and clean benches are frequently scanned or probed for leaks. Increasingly, particle detectors that count individual particles are used to scan filters. The equations that govern the scanning of high-efficiency filters with particle counters have been derived. The assumptions that bound the applicability of the equations are stated. The relationships provide the means to determine the appropriate linear scan rate and to understand the effect of the test parameters on the duration and accuracy of the test. The linear scan rate is derived in terms of a leak flow rate but a method is presented to relate the leak flow to the traditional leak penetration. Further, a method is described to standardize the definition of leak penetration to eliminate the dependence of measured leak penctration on the instrument used to measure it. The linear scan rate is shown to depend on the number of particle counts used to characterize the threshold leak. The statistical impact of the count used to calculate the linear scan rate is described.
Measured Effects of Reduced Flow Velocity in a Laminar Flow Cleanroom
Authors: Carr Peter , Rapa Angelo , Fosnight William , Baseman Robert , Cooper Douglas
Published: November 2020

Vertical laminar flow (VLF) cleanrooms generally operate with airflows between 60 feet per minute (fpm) and 110 fpm. Tests were performed to evaluate the effects on particle contamination levels when the airflow velocity in a FED-STD-209 Class 1 VLF cleanroom was reduced. The cleanroom normally operates at 90 fpm. Measurements of surface particle concentrations were made on settling monitor wafers and on wafers carried in an open cassette. Optical particle counters measured the airborne particle concentrations at several locations.

Results at 100 fpm and 50 fpm, respectively, for particles larger than or equal to 0.3 μm in optical equivalent diameter were −0.0002 and +0.0029 particles/sq cm/hr for the settling wafers and 0.009 and 0.024/sq cm total for the wafers carried for 5 hr in the open cassettes. Summary statistics are provided for the airborne and surface particle counts.

Deposition velocity is the ratio of surface deposition rate to airborne concentration. For the monitor wafers at the lower flow, the calculated particle deposition velocities were near 0.003 cm/sec, which is within the range expected from theory and experiments in the literature.
Design Considerations for Minienvironment Cleanrooms (Issues, Options, and Concepts)
Authors: Lynn Charles
Published: November 2020

Many new cleanroom facilities are being designed and constructed using various minienvironment concepts. This paper presents facility concepts that are being implemented today and those that will be implemented in future construction. The author will present factors and issues that lead owners to the decision to use minienvironments. Also included is the impact of the decision on facility design. A comparison of various designs (including first cost and operating cost) will be presented. Case studies will show the advantages of implementing minienvironments, flexibility issues, and how to best take advantage of the potential operating cost savings.
A Comparison of Commercial Cleanroom Wiping Materials for Properties Related to Functionality and Cleanliness
Authors: Oathout J. , Mattina Charles
Published: November 2020

Using published procedures, 10 commercially available cleanroom wiping materials were tested and evaluated for characteristics related both to functionality and to contamination. The sorptive capacities of these 10 wipers were found to span a range from 100 to 500 mL/m2, while rates of sorption cover two orders of magnitude, from 30 to 3000 mL/m2/s. Particles are reported as readily releasable particles, those easily removed from wipers using water, and as particles which are generated in response to the administration of frictional energy. Data are also given for extractible matter with two solvents, water and 2-propanol, and for the total mass of inorganic matter as measured by the level of high-temperature ash. The data related to contamination cover several orders of magnitude and are reported not only per unit area and per unit mass, but also on a unique basis introduced here: unit of filth per unit of function.
Gaseous Contaminant Measurement for Semiconductor Processing by Diode Laser Spectroscopy
Authors: McAndrew James , Inman Ronald , Jurcik Benjamin
Published: November 2020

Tunable diode laser absorption spectroscopy (TDLAS) is a novel tool for purity measurement in microelectronic process gases and environments. It is compatible with any matrix gas and extremely sensitive. This paper describes the application of a laboratory TDLAS instrument to measurement of CO, CO2, and H2O with sub-ppb sensitivity, including determination of a CO level of 0.35± 0.2 ppb in nitrogen samples from an air separation plant. Fluid dynamic simulation was used to optimize the design of the cell used for H20 measurements. TDLAS lends itself to the study of contamination sources in situ. As examples, measurements of CO generation in sampling vessels and of CO2 outgassing in an electropolished stainless steel chamber are briefly discussed.
Environmental Stress Screening for a Massively Parallel Vision Computer
Authors: Kostic Andrew , Wallace Robert
Published: November 2020

A massively parallel vision computer system was having serious field reliability problems associated with CMOS Programmable Logic Array. The manufacturer's existing ESS program was ineffective for removing the product defects. The supplier of the devices was unable to identify the failure mechanism. The root cause of the problem was assumed based on the information from parts of similar technology. An ESS program was developed using available equipment and resources. The ESS process reduced field returns from a high of 45 percent to less than 1 percent. Quiescent current screening was developed and implemented as part of a part-level screening process. Long-term corrective actions were identified, and the system level screening process was further improved to reduce cost and increase effectiveness.
Statistical Energy Modeling Techniques for Space Station Truss Segments
Authors: Smith Leland , Bremner Paul
Published: November 2020

Statistical energy analysis (SEA) was performed on models of International Space Station (ISS) truss segments. These segments are large truss structures built up from I-beam members. The purpose of this analytical program is to determine the random vibration environment for equipment mounted on these segments. The equipment is mounted to secondary structural built-up plates in most instances. In general, the secondary structure is more rigid than typical aerospace structures because of the large spans between the primary truss members. This presents a challenge to the SEA methodology because of the low modal density of both the primary and the secondary structure, and novel approaches to the problem were identified. The need to test verify these modeling approaches was apparent. On the previous Space Station Freedom program, a developmental vibroacoustic test of a space station-like truss segment was conducted. The development test specimen was modeled in a similar manner to the ISS segments and predicted responses were compared with test data. This paper discusses the modeling methods determined to be effective for these structures
Energy Savings in Cleanrooms from Demand-Controlled Filtration
Authors: Faulkner David , Fisk William , Walton John
Published: November 2020

In cleanrooms, very low particle concentrations are maintained by recirculation of air at a high rate (e.g., 600 room air volumes/hr) through highly efficient air filters. Results are reported in a Class M3.5 (Class 100) cleanroom with 28 m2 (300 ft2) floor area, where significant energy savings were realized by controlling the rate of air recirculation through the filters in response to real-time measurements of particle concentrations. An inexpensive, $2500, optical particle counter was used to measure particle concentrations. The effect of varying the recirculation airflow rate on particle concentrations was investigated. Changes in recirculation fan speeds of 10 percent or greater did not cause a noticeable particle release from filters or resuspension from indoor surfaces. With new automatic control systems in operation, there were occasional, usually fewer than 10/day, nonconsecutive l-min episodes in which the particle concentration exceeded Class M3.5 (Class 100) status. Depending upon the choice for baseline energy use, the energy consumption of the recirculating fans was reduced by 60 to 80 percent, and the estimated payback period for a 90 m2 (1,000 ft2) Class M3.5 (Class 100) cleanroom is from 1 to 4 yr.
Particle Behavior in Vacuum Systems: Implications for In-Situ Particle Monitoring in Semiconductor Processing Equipment.
Authors: Kinney Patrick , Bae Gwi-Nam , Pui David , Liu Benjamin
Published: November 2020

The flow of aerosol in vacuum conditions representative of many semiconductor processes (100 sccm, 1 Torr). was investigated. The study was performed using aerosols with highly nonuniform spatial distributions. An ideally nonuniform aerosol was produced by generating an aerosol beam using an aerodynamic lens. The flow containing the aerosol beam was drawn through vacuum system components. The size of the beam was measured upstream and downstream of these components by collecting the aerosol on a filter and observing the deposition pattern. Very little mixing phenomenon was observed. These results point to a potential limitation in the methods employed by the semiconductor industry for in-situ particle monitoring in vacuum systems. A simple solution to this flaw is suggested.
A Check List for Developing Accelerated Reliability Tests
Authors: Caruso Hank
Published: November 2020

This paper provides the newcomer to or casual practitioner of environmental reliability testing with an integrated overview of important issues and considerations associated with accelerated reliability testing. These include step-stress testing, durability test time compression, and environmental stress screening. Other issues include the purpose of the test, the information needs of the customer, and the optimum level of assembly for testing. This information is presented in the form of a question and answer thought process that can be applied in commercial or military test situations.
In-Line Moisture Monitoring in Semiconductor Process Gases by a Reactive-Metal-Coated Quartz Crystal Microbalance
Authors: Wei Jian , Pillion John , Hoang Chi
Published: November 2020

A new in-line sensor for trace moisture monitoring has been developed based on a piezoelectric quartz crystal microbalance (QCM) coated with a reactive metal thin film. The properties of the metal coating and QCM allow the sensor to have fast response and fast recovery to moisture in the process gas stream. The properties of the metal-coated QCM also allow the sensor to be compact so it can be in-line in the gas distribution system and readily integrated into the process tools. This paper presents the principle of moisture detection using this technology. The experimental results of accuracy, limit of detection (< 1 ppb), and error analysis of this sensor in parallel with atmospheric pressure ionization mass spectrometry (APIMS) are presented. The experimental setup and procedures are described. The effect of an upstream gas purifier on its rate of response was also studied and the results are presented and discussed. The applications of this technology in semiconductor processing are briefly mentioned.
Test Philosophies for the New Millennium
Authors: Larson Timothy , Newell James
Published: November 2020

Current research at the Jet Propulsion Laboratory (JPL) is directed toward the optimization of future spacecraft testing. Force-limited vibration studies, conducted during several recent space vehicle programs, have been extremely successful in improving the quality and realism of hardware trials. Single versus triaxial vibration research is also in progress, with a similar objective of test realism enhancement. In addition, use of the Environmental Test Effectiveness Assessment (ETEA) process has helped to identify those tests which most effectively isolate hardware defects. In an effort to streamline the development of requirements, JPL has recently begun to establish a "2-sigma" generic environmental envelope. In the future, such an envelope could allow "off-the-shelf" hardware to be flown on a number of standard launch vehicles. In a related study, the Accurate, Cost Effective Qualification (ACEQ) program has been developed to correlate system requirements with failure modes, and then assess the effectiveness of test, analysis and process control in identifying these modes.
Considerations regarding the Statistics of Particle Counting
Authors: Bzik Thomas
Published: November 2020

The control of particulate contamination is integral to many semiconductor manufacturing processes. In these processes, particle contamination levels are measured and compared with performance standards and statistically analyzed to determine the process state. Such particle data often exhibit a high relative standard deviation. This impacts the ability to make appropriate decisions about the state of process cleanliness. Further compounding the problem is that traditional statistical tools (e.g., normality assumption, Shewhart control charts) may perform poorly when applied to particle data. This paper presents an overview of many key issues surrounding the application and misapplication of statistical methods to particle data.
Characterizing the Commercial Avionics Thermal Environment for Field Reliability Assessment
Authors: Cluff Kevin , Robbins Dan , Edwards Tom , Barker Donald
Published: November 2020

Defining environmental loading is often the most uncertain part of the electronics reliability calculation. This paper demonstrates a practical methodology to measure and characterize the dynamic thermal history of the commercial airplane environment. To reduce irregular field thermal cycles, an algorithm is presented that preserves key information necessary for viscoplastic solder fatigue analysis. As an example. the IPC solder model will be used to evaluate 20 termination leadless ceramic chip carriers on nonconstrained printed wiring boards. This methodology will enable more realistic thermal fatigue reliability assessments and acceleration test specifications.
Rinsing: A Critical Process in Contamination Removal
Authors: Christenson Kurt
Published: November 2020

The rinsing process of silicon wafers is normally carried out in an "overflow" bath in which water flows past the wafers at average velocity of 1 cm/s. But the velocity is zero at the wafer surface. The efficiency of rinsing is limited by the rate at which contaminants diffuse away from the silicon surface and into the flow stream. This paper reports the improvement in rinsing efficiency gained by repeating a 1-min cycle of first allowing the contaminants to diffuse into the stagnant layer and then "dumping" the rinse tank to remove most of the contaminated stagnant layer. A further 10-fold improvement in rinsing efficiency per rinse cycle can be achieved by spinning the wafer and using centrifugal force to remove a greater fraction of the stagnant layer. This allows the complete removal of soluble contaminants with a 20-fold reduction in water usage compared to present immersion techniques.
Isolation Ratio and Particle Performance Measurement of a SMIF System
Authors: Liu Benjamin , Yoo Seong-Ho
Published: November 2020

This paper discusses the performance evaluation of a SMIF (Standard Mechanical Interface) system. A two-chamber experimental system is used with one chamber providing the test atmosphere of the cleanroom and the other providing the test atmosphere of the minienvironment. The cleanroom atmospher can be varied by adjusting the amount of particles injected into the chamber. Particle concentration ranges from 1,000/ft-3 to 10 million/ft3 can be created in the chamber to simulate different cleanroom conditions. The atmosphere of the second chamber is maintained at Class I or better equivalent by means of a self-powered ultra-low penetration air (ULPA) filter blower unit. By means of this system, the ability of the SMIF system to isolate the contaminants in the cleanroom atmosphere from the minienvironment atmosphere was measured. In addition, the particles added to the wafer during wafer cassette handling by the SMIF-Arm were also measured by a wafer scanner. The results indicate that the SMIF system tested is capable of providing extremely high isolation ratios in terms of its ability to isolate the cleanroom atmosphere from the atmosphere of the minienvironment. Isolation ratios in excess of 1 million to 1 or better have been measured. The measured particle per wafer per pass (PWP) numbers were generally around 0.02 or less for most wafers, with the average at 0.0118.
Büyük Menderes Nehri’nde (Aydın) Yaşayan İki Tatlı Su Balığı Türünün Kas Dokularındaki Total Yağ Asidi Kompozisyonunun Araştırılması
Authors: BAYAR İrem , İNCİ Aslıhan , ÜNÜBOL AYPAK Serap , BİLDİK Ayşegül
Published: November 2020

Bu çalışmada Büyük Menderes Nehri’nde (Aydın) yakalanan Scardinius erythrophthalmus (kızılkanat) ve Anguilla anguilla (yılan balığı) tatlı su balığı türlerinin kas dokusundaki yağ asidi bileşimlerinin karakterize edilmesi ve ω3/ω6 yağ asidi oranlarının belirlenmesi amaçlandı. Balıkların kas doku örneklerinden elde edilen yağ asidi metil esterleri gaz kromatografisi (GC) ile analiz edildi. En bol bulunan doymuş yağ asitleri S. erythrophthalmus türünde stearik asit C18:0 (%24.554±0.249); A. anguilla türünde ise palmitik asit C16:0 (%19.49±0.643) olarak tespit edildi. Her iki balık türündeki tekli doymamış yağ asitleri için ise en büyük yüzdeye sahip olanlar oleik asit C18:1 ω9 (S. erythrophthalmus türünde %18.03±0.520; A. anguilla türünde %33.44±0.336) ve palmitoleik asit C16:1 ω7 (S. erythrophthalmus türünde %9.916±0.484; A. anguilla türünde %10.96±0.753) olarak belirlendi. Eikosapentaenoik asit (EPA) C20:5 ω3 ve dokosaheksaenoik asit (DHA) C22:6 ω3 değerleri S. erythrophthalmus ve A. anguilla türleri için analiz edildi ve sırasıyla %5.68±0.406; %3.72±0.242 ve %3.87±0.505; %9.24±0.583 oranlarında tayin edildi (p
Trastuzumab exposure in early pregnancy for a young lady with locally invasive breast cancer
Authors: Pianca Natasha , George Mathew
Published: November 2020

The available literature on the effects of trastuzumab on pregnancy in the first trimester is limited. Case reports discuss the presence of oligohydramnios on fetal USS that result in a living baby that seemingly lacks any abnormalities. There may also be a link with higher rates of spontaneous abortion. We describe a young 32 year old on trastuzumab for a locally invasive HER2-positive breast cancer who became pregnant with fetal exposure to the treatment. After cessation of trastuzumab at 28 weeks, she delivered a healthy baby girl at 37 weeks gestation who, at 7 years of age now, still does not display any evidence of negative effects of trastuzumab exposure.
FLT3-ITD-positive acute myeloid leukemia: risk of relapse and refractory
Authors: A. Lynch Bill , M. Lyman Suzan
Published: November 2020

The FMS-like tyrosine kinase 3 (FLT3-ITD) acute myeloid leukemia (AML) often present with more aggressive disease and have a significantly higher marrow blast percentage, higher likelihood of relapse, and shorter survival. Activating mutations of the kinase occur in about one third of patients with AML. The therapeutic approach for these patients has traditionally included intensive induction chemotherapy, followed by consolidative chemotherapy or hematopoietic cell transplantation (HCT). A number of small-molecule kinase inhibitors such as lestaurtinib (CEP-701), midostaurin (PKC412), and tandutinib (MLN518) block the autophosphorylation of FLT3 and lead to inhibition of cell proliferation and induction of apoptosis; they have demonstrated clinical activity in patients with AML, in particular those with mutations. This review summarizes what is known regarding the FLT3-ITD targeting therapy.
Critical levels of serum myeloperoxidase in patients with systemic lupus erythematosus
Authors: Kishihara Yojirou , Kawai Osamu
Published: November 2020

Systemic lupus erythematosus (SLE) is a systemic autoimmune and inflammatory disease characterized by the polyclonal activation of T and B lymphocytes, production of autoantibodies, and formation of immune complex. We measured the serum level of myeloperoxidase (MPO) in patients with SLE (n = 97) and in healthy controls (n = 88) and assessed the correlation between the serum myeloperoxidase (MPO) levels and established disease-activity indexes. All patient samples with SLE analyzed showed higher serum levels of MPO than healthy controls. Higher MPO levels were observed in SLE patients with increased C-reactive protein (P=0.001), as well as in those with highly active disease (P<0.005). Our concluded is that the associations between MPO and the disease variables of SLE patients support a role for MPO in the inflammatory process of the disease.
Clinical profile of patients with inferolateral myocardial infarction: a comparison study
Authors: Panda Sibaram , Jena Sunil Kumar , Pattanaik Uttam Kumar
Published: November 2020

Background: Patient with lateral wall changes in inferior wall myocardial infarction (MI) usually ignored most often. However above lateral MI changes in the clinical setting of inferior wall MI usually impact on final clinical outcome and prognosis of the patients. Our aim of the study is observe diversity in clinical profile of inferolateral MI in comparison to patient with inferior wall without any lateral wall MI changes.Methods: Current study enrolled 405 patients admitted to cardiology emergency with inferior wall MI. Patients divided into three groups on the basis of ECG changes, inferolateral (group A), isolated inferior wall MI (group B) and inferior wall MI with RVMI (group C). Patients with RVMI (group C) excluded from the group. Clinical profile and outcomes compared between group A and B.Results: Around 33.8% pts with inferior wall STEMI have ECG changes of lateral wall AMI. STEMI equivalent in lead V1, V2 which is the most common ECG presentation, seen in 65% inferolateral patients. 45.7% of population of inferolateral MI are above age group of 60 years. 66.2 % of the patients with inferolateral MI having two or more risk factors. Dyspnoea is one of common symptom seen in 29.9% patients. Statistically significant number of patients in inferlateral MI have clinical picture of LVF (crepitation, S3), higher Killip class as compared to inferior wall MI. Incidence of complications like LVF, MR, VT, death is significantly higher in this group.Conclusions: Around 1/3rd patient with lateral MI changes seen in inferior wall MI patients. STEMI equivalent changes in anterior precordial leads are most common ECG presentation. More no patients are older and with multiple risk factors. Complication and death are higher in this group. So meticulous attention should be given to patients with lateral wall MI changes in inferior wall MI.
Community Monitoring Improves Public Service Provision at Scale: Experimental Evidence from a Child Development Program in Nicaragua
Authors: López Boo Florencia , Leer Jane , Kamei Akito
Published: November 2020

Expanding small-scale interventions without lowering quality and attenuating impact is a critical policy challenge. Community monitoring overs a low-cost quality assurance mechanism by making service providers account-able to local citizens, rather than distant administrators. This paper provides experimental evidence from a home visit parenting program implemented at scale by the Nicaraguan government, with two types of monitoring: (a) institutional monitoring; and (b) community monitoring. We find d a positive intent-to-treat effect on child development, but only among groups randomly assigned to community monitoring. Our findings show promise for the use of community monitoring to ensure quality in large-scale government-run social programs.
Costos y beneficios de la descarbonización de la economía de Costa Rica: Evaluación del Plan Nacional de Descarbonización bajo incertidumbre (Resumen ejecutivo)
Authors: Groves David G. , Syme James , Molina-Pérez Edmundo , Calvo Carlos , Víctor-Gallardo Luis , Godinez-Zamora Guido , Quirós-Tortos Jairo , De León Felipe , Meza Murillo Andrea , Saavedra Gómez Valentina , Vogt-Schilb Adrien
Published: November 2020

Reconociendo la incertidumbre sobre el futuro, evaluamos miles de futuros plausibles diferentes para comprender el rango de posibles vías de descarbonización y beneficios netos para la economía costarricense. En todos menos 22 de los más de 3.000 futuros posibles considerados, la implementación del plan de descarbonización conduciría a beneficios económicos que superarían los costos. Nuestros resultados destacan la importancia del cambio modal y las tecnologías de cero carbono en el sector del transporte, aumentando el secuestro de carbono en el sector forestal y la reducción de emisiones en los procesos industriales y ganaderos, para lograr emisiones netas cero. Este trabajo ha ayudado a construir herramientas y capacidad para evaluar las estrategias de descarbonización, que se utilizarán para apoyar la actualización de las Contribuciones Determinadas a Nivel Nacional de Costa Rica, su compromiso con la comunidad internacional en virtud del Acuerdo de París. Nuestro enfoque se puede reproducir en otros países interesados en analizar las implicaciones económicas de los caminos hacia la prosperidad libre de carbono.
Child Care Markets, Parental Labor Supply, and Child Development
Authors: Berlinski Samuel , Ferreyra María Marta , Flabbi Luca , Martin Juan David
Published: November 2020

We develop and estimate a model of child care markets that endogenizes both demand and supply. On the demand side, families with a child make consumption, labor supply, and child-care decisions within a static, unitary household model. On the supply side, child care providers make entry, price, and quality decisions under monopolistic competition. Child development is a function of the time spent with each parent and at the child care center; these inputs vary in their impact. We estimate the structural parameters of the model using the 2003 Early Childhood Longitudinal Study, which contains information on parental employment and wages, child care choices, child development, and center quality. We use our estimates to evaluate the impact of several policies, including vouchers, cash transfers, quality regulations, and public provision. Among these, a combination of quality regulation and vouchers for working families leads to the greatest gains in average child development and to a large expansion in child care use and female labor supply, all at a relatively low fiscal cost.
El Instituto de Ciencias Naturales (1936-2019): de la historia natural al conocimiento de la biodiversidad en Colombia
Authors: Amat-García Germán , Aguirre-Ceballos Jaime
Published: November 2020

Se describen y se relacionan en una línea de tiempo los antecedentes institucionales sobre el origen y los hechos más notables del Instituto de Ciencias Naturales, y se analizan los alcances de sus contribuciones al conocimiento de la historia natural en Colombia durante el siglo XX, así como los logros institucionales más importantes en el transcurso de las dos primeras décadas del siglo XXI en la docencia, la investigación y la divulgación científica en torno a la biodiversidad y la conservación de la naturaleza.
Pyrolysis system to obtain carbonaceous material from rice husk used as a precursor
Authors: Javier R. Javier R. , Vacca-Casanova Ana B. , Cuy-Hoyos Carlos A.
Published: November 2020

We present the development and validation of a pyrolysis system with a controlled nitrogen atmosphere for the production of carbonaceous materials from biomass elements. Our objective was to use rice husk as a precursor to produce carbonaceous material and explore its application in different technological fields. In Colombia, over 800.000 tons of rice are produced every six months by the leading producing regions such as the Orinoquia region and the provinces of Tolima and Huila, among others. This system provides the opportunity to use agro-industrial waste such as rice husk, an environmental contaminator, and convert it into a useful and value-added material for the development of science and technology in emerging technological fields. Analyses performed using electron scanning microscopy (SEM) have shown that the synthesized material is a porous carbonaceous substance composed of irregular fibers with a hollow internal structure between 5 and 30 μm in size. The Raman spectra show a vibrational response of graphene oxide (GO) multilayer type. These results suggest the GO derived from rice husk can be a candidate for the development of applications in technological areas such as flexible electronic devices and systems, sensors, batteries, supercapacitors for energy storage, and bioremediation systems, among other technological applications.
Estudio del semiconductor magnético ZnO dopado con Fe obtenido por aleamiento mecánico
Authors: Zamora Alfonso Ligia Edith
Published: November 2020

El sistema ZnO dopado con Fe presenta buenas propiedades como semiconductor magnético diluido para aplicaciones en espintrónica. En este artículo se hace una revisión de algunas propiedades estructurales y magnéticas del ZnO dopado con Fe. Inicialmente, se hace un resumen de los conceptos básicos para entender en qué consiste la espintrónica y sus posibles aplicaciones. Posteriormente, se presenta el estudio de dicho sistema mediante difracción de rayos X, espectroscopía Mössbauer y magnetometría de muestra vibrante en muestras obtenidas por aleamiento mecánico en diferentes condiciones de preparación. En la primera se aumentó la concentración de Fe de 3 a 10 % en un tiempo de molienda de 36 horas y una relación entre el peso de las bolas y el peso de los elementos (relación de peso bolas-polvo, RPB) de 15:1. En este caso se probó que hubo una concentración límite de Fe, aproximadamente de 5 %, que se diluyó dentro de la red del ZnO; el resto del Fe apareció segregado en la muestra. En la segunda condición se fijó la concentración de Fe en 10 % y se variaron las horas de molienda. Se encontró que después de 24 horas, la muestra se consolidó, pero el Fe no se diluyó completamente dentro de la red de ZnO. Por último, usando una concentración de 10 % en Fe y aumentando la RPB se encontró que todos los átomos de Fe se diluyeron dentro de la fase de ZnO y no quedaron segregados de Fe en la muestra, lo que se explica porque al aumentar la relación RPB aumenta la energía.
In vitro effect of four fungicides on Colletotrichum gloeosporioides causing anthracnosis on the Red Globe grape variety
Authors: López-Zapata Silvia Patricia , Castaño-Zapata Jairo
Published: November 2020

Anthracnose is considered one of the most important diseases of grape crops. In this study, we evaluated the in vitro effect on potato dextrose agar (PDA) of four fungicides: benomyl (Benlate® 50 WP), carbendazim (Belico ® 500 SC), chlorothalonil (Odeon® 720 SC), and dodine (Syllit ® 400 SC) using three concentrations on a Colletotrichum gloeosporioides isolate. This species complex causes anthracnose on the Red Globe grape variety. The concentrations of each fungicide were: benomyl at 0.5, 0.25, and 1 g.L-1; carbendazim at  0.6, 0.3, and 1.2 mL.L-1; chlorothalonil at 2.4, 1.2, and 4.8 mL.L-1, and dodine at 1.6, 0.8, and 3.2 mL.L-1. Evaluated the inhibition of mycelial growth and the sporulation of the fungus. The fungus mycelium exposed to the commercial dose of the fungicides was observed using environmental scanning electron microscopy (ESEM). We used a completely randomized design with 13 treatments and five repetitions. Our results showed a degree of differential efficacy for the four fungicides and their effects were directly proportional to the dose used, benomyl and chlorothalonil being the most efficient in controlling the mycelial growth of the fungus. At the commercial dose, sporulation was inhibited at a higher rate by benomyl showing no statistically significant differences with the other products except chlorothalonil and dodine when the recommended dose was reduced by half. The damage observed by ESEM on the fungus mycelium ratified the effect obtained in vitro, i.e., deformed hyphae and irregular growth. The results of this study, complemented by electron microscopy, are promising for the appropriate selection of the best fungicides for controlling anthracnose on grape fruits, subject to the timely and correct diagnosis of the disease.
Comparación de la composición y de la actividad antioxidante del aceite esencial de manzanilla (Matricaria chamomilla L.) obtenido mediante extracción con fluidos supercríticos y otras técnicas verdes
Authors: Melo-Guerrero Maria Melo , Ortiz-Jurado Daniel Esteban , Hurtado-Benavides Andrés Mauricio
Published: November 2020

Se comparó la composición química y la actividad antioxidante del aceite esencial de manzanilla (Matricaria chamomilla L.) obtenido mediante extracción con fluidos supercríticos (supercritical fluid extraction, SFE) y otras técnicas de extracción verdes (arrastre con vapor, AV; hidrodestilación, HD; destilación por arrastre con vapor y extracción simultánea con solvente orgánico, DES, y maceración, MC). Se optimizó el proceso de extracción evaluando el efecto de la temperatura (T) (35-65 °C) y la presión (P) (90-210 bar) en el rendimiento de la extracción (% p/p) y se determinó que una temperatura de 65 °C y una presión de 210 bar eran las mejores condiciones de extracción (0,87 % p/p). La composición química se analizó por cromatografía de gases acoplada a espectrometría de masas (GC-MS) y se establecieron los constituyentes con base en sus patrones de fragmentación y el índice de retención de Kovats. La actividad antioxidante se evaluó mediante el método ABTS. Los componentes principales fueron enindicicloeter, β-farneseno y óxido de bisabolol A. Los resultados de los análisis de GC-MS indicaron que la composición y concentración del aceite esencial cambiaron al emplear diferentes métodos de extracción, por ejemplo, en los aceites extraídos por MC el componente mayoritario fue el enindicicloeter, en tanto que en los extraídos por HD fue el β-farneseno y con DES fue el óxido de bisabolol A. El aceite obtenido por AV (27,56 μmol de trolox/ml de aceite) presentó una mayor actividad antioxidante en comparación con los otros métodos de extracción, incluso comparado con el SFE (15,25 μmol de trolox/ml de aceite).
Análise Epistemológica do Currículo e das Ações Pedagógicas no Ensino Híbrido
Authors: Brito Jorge Maurí­cio da Silva , Pasini Edna Maria Biz
Published: November 2020

As novas tecnologias já fazem parte da nossa vida, de modo que já não podem ser vistas como simples recursos mas como instrumentos fundamentais para o exercício de nossa própria humanidade. O ensino híbrido é uma possibilidade de fusão entre os espaços virtual e presencial. Neste trabalho apresentamos uma reflexão crítica e significados para o que é ensino híbrido e qual a sua lógica de sistematização do conhecimento, com o fito de mostar as interrelações entre currículo e ações pedagógicas, experiência e conhecimento. O método adotado foi o de revisão teórica. E o principal resultado foi que a aprendizagem não será híbrida apenas se professor e aluno estiverem em lugares diferentes, mas na forma como a ação docente provoca a experiência do conhecimento nos alunos; a ideia de virtual não é a de espaço físico separado, mas de lugar onde a inteligência encontra subsídios adequados para se abrir a novos saberes.
Palavras-chaves: Análise. Ensino. Híbrido. Currículo. Ações pedagógicas
CONSULTA DE ENFERMAGEM EM PUERICULTURA NA PERSPECTIVA DE MÃES ATENDIDAS PELA ESTRATÉGIA SAÚDE DA FAMÍLIA
Authors: MONTEIRO MARIANE GICELI ATAIDE , DE AZEVEDO ELISANGELA BRAGA , LIMA MARIA KAROLINE SANTOS , BARBOSA HEVILLYN CECÍLIA VENTURA , BARBOSA JOSEFA CRISTINA GOMES , CERQUEIRA ANA CAROLINA DANTAS
Published: November 2020

Objetivo: analisar a compreensão das mães sobre a consulta de enfermagem em puericultura na Estratégia Saúde da Família de um município paraibano. Método: pesquisa descritiva, exploratória, com abordagem qualitativa, rea- lizada com mães de crianças entre 0 e 2 anos. Dados coletados por entrevista semiestruturada e analisados pela técnica análise de conteúdo. Resultados: participaram do estudo 13 mães com idade entre 19 e 25 anos. Emergiram três categorias temáticas: “compreensão de mães sobre a consulta de enfermagem em puericultura”; “papel do en- fermeiro nas orientações durante a puericultura e importância da construção de vínculo com as mães”; e “fatores que interferem na adesão das mães à consulta de enfermagem em puericultura”. Conclusão: as mães compreendiam que a consulta de enfermagem em puericultura proporcionava espaços de diálogos e abordagem humanizada, contribuindo para melhoria da saúde da criança, mas os horários de atendimento coincidiam com horário de trabalho, dificultando para levar as crianças. Descritores: Saúde da Criança. Consulta de Enfermagem. Cuidado da Criança. Atenção Primária.
COVID-19 NAS PRISÕES: EFEITOS DA PANDEMIA SOBRE A SAÚDE MENTAL DE MULHERES PRIVADAS DE LIBERDADE
Authors: Santos Gabriel Da Cruz , Simôa Tainá Cerqueira , Bispo Tânia Christiane Ferreira , Martins Ridalva Dias , Santos Denise Santana Silva dos , Almeida Aglaya Oliveira Lima Cordeiro de
Published: November 2020

Objetivo: investigar o autorrelato de sintomas de ansiedade relacionados à Covid-19 entre mulheres encarceradas. Método: estudo transversal, realizado em uma unidade prisional de Salvador, Bahia, no período de abril a maio de 2020. Os dados foram coletados por meio de questionário, sendo analisadas as frequências relativas e absolutas. Resultados: participaram 41 mulheres, majoritariamente jovens, de baixa escolaridade, mães solo e negras. 95% da amostra relatou algum sintoma de ansiedade. Encontrou-se alta prevalência de preocupação consigo, com a segurança no presídio e com a família diante da pandemia. A maioria das mulheres encontrou mecanismos para atenuar os impactos psicológicos da pandemia. Conclusão: a fragilização dos vínculos familiares e a sensação de insegurança relacionada à Covid-19 podem contribuir para o desenvolvimento de sintomas ansiosos. As atividades laborativas, de lazer, a prática de atividade física e as práticas religiosas devem ser estimuladas, pois auxiliam a reduzir o risco de desenvolvimento de transtornos mentais. Descritores: Prisioneiros. Infecções por Coronavírus. Saúde Mental. Mulheres. Ansiedade.
On Some Aspects of Geometry of Almost C(λ)-manifolds
Authors: Rustanov A.R. , Polkina E.A. , Kharitonova S.V.
Published: November 2020

In this paper almost C(λ)-manifolds are considered. The local structure of Ricci-flat almost C(λ)-manifolds is obtained. On the space of the adjoint G-structure, necessary and sufficient conditions are obtained under which the al-most C(λ)-manifolds are manifolds of constant curvature and the structure of the Riemannian curvature tensor of an almost C(λ)-manifold of constant curvature is obtained. Relations are obtained that characterize the Einstein almost C(λ)-manifolds. It is proved that a complete almost C(λ)-Einstein manifold is either holomorphically isometrically covered by the product of a real line by a Ricciflat Kähler manifold, or is compact and has a finite fundamental group. For almost C(λ)-manifolds that are -Einstein, analytic expressions for the functions  and  characterizing these manifolds are obtained. It is shown that an almost C(λ)-manifold has an Ф-invariant Ricci tensor. We study also almost C(λ)-manifolds of pointwise constant Ф-holomorphic sectional curvature.
Distribution of Gold and Associated Ore-Bearing Elements in Gold-Copper-Pyrite Ores of the Kyzylbulag Deposit (Lesser Caucasus, Azerbaijan)
Authors: Mansurov M.I. , Galandarov B.H. , Karimli U.I. , Huseynov A.I.
Published: November 2020

The article presents the results of studies of the distribution of gold and associated ore elements in gold-copper pyrite ores of the Kyzylbulag deposit. It was established that the elemental composition of ores and host rocks of the deposit includes Cu, Pb, Au, Ag, Ni, As, Sb, Bi, and Mo, of which Au, Cu, Ag, and Zn are the more stable. The behavior of elements was also studied for the entire ore body, as a result of which they are divided by cluster analysis at R (5 %) - 0.1 into two groups: 1) Au, Cu and Ag; 2) Pb and Zn. The closest relationship in the first group was found between Au and Cu, Au and Ag, Ag and Cu; and in the second, between Pb and Zn. Acquired results confirm that gold and the copper are the major components of ore in the field expressed generally in the mineral paragenesis of chalcopyrite - native gold shown in the independent hydrothermal stage of ore deposition.