cssi/SciSciGPT-SciSciNet huggingface dataset:
Process Simulations and Techno-Economic Analyses

Introduction A process simulation is the representation of a thermal or chemical transformation by a mathematical model that is solved to provide information about mass and energy requirements, equipment performance, and overall process feasibility. They are system level models used for economic calculations, energy efficiency analyses, and process comparisons. Component level information such as reactor geometry, mixing and hydrodynamics, and transport phenomena, as well as molecular level information such as surface area, reaction mechanism, and electronic interactions, are not included. Beginning with FlowTran, developed by Monsanto in the 1950s and 1960s, several process simulation software packages have since been developed, including ProSim, PRO/II, gPROMS, ChemCAD, and Aspen Plus ® , and they play an important role in process development by allowing for the evaluation of a commercial scale plant based on available experimental results. The process simulation software that is used extensively throughout academic research and industrial operations is Aspen Plus ® . Aspen was developed in the late 1970s at Massachusetts Institute of Technology for the United States Energy Research and Development Administration (now United States Department of Energy or USDOE). The project objective was to develop a computer program to aid in performing process evaluations; mainly process economics. Today, Aspen has evolved into Aspen Plus ® and, as part of the AspenOne package software suite, has become the essential plant and process design software program. Aspen Plus ® provides complete flexibility in designing a process simulation. Every new process begins by specifying the component species and the property method used for calculating the component species thermodynamic properties. Together, these two required specifications display the strength of the Aspen Plus ® software program, due to its extensive chemical databank, available methods for calculating thermodynamic properties, and ability to adjust property values when necessary. Once the component species and property methods have been selected, Aspen Plus ® assumes control and calculates the thermodynamic properties based on user input, and only allows the inputs required to satisfy the degrees of freedom. The chemical looping partial oxidation examples and the results presented in this chapter were obtained using Aspen Plus ® (AspenTech), and they are available on the website as supplemental material.
Introduction to Machine Learning for Digital Library Applications

This tutorial begins with an overview of the major branches of machine learning (ML) and then provides more thorough coverage of deep neural networks. It covers key concepts, tools, experimental methods, applications, evaluation measures and associated issues for supervised learning (regression and classification), unsupervised learning (clustering and dimensionality reduction), semi-supervised and active learning (which combine the former approaches), and reinforcement learning. The deep neural network discussion covers convolutional neural networks (CNNs), recurrent neural networks (RNNs), word embeddings and related techniques. The discussion will be grounded on digital library (DL) - related applications and will highlight issues, techniques and tools associated with processing big data.
IN VITRO REPLICATION OF YEAST 2-μm PLASMID DNA

ABSTRACT A soluble extract from exponentially growing yeast Saccharomyces cerevisiae initiates semiconservative replication of exogenously added yeast 2-μm plasmid DNA and Escherichia coli chimeric plasmids containing the 2-μm DNA. The replication system utilizes about 10% of the added DNA molecules and completes one round of replication. The major products in early stages of replication are Θ (“eye”) forms of plasmid DNA which start within one of the 599 base-pair inverted repeats (at 140 ± 50 nucleotides from the end of the inverted repeat) and DNA replication proceeds bidirectionally and discontinuously. Temperature sensitivity of in vitro 2-μm DNA synthesis is exhibited by the extracts prepared from the cell division cycle mutant, cdc8 , suggesting that this system resemble in vivo 2-μm plasmid DNA replication.
Pathological and Physiological Double-Strand Breaks: Roles in Cancer, Aging, and the Immune System

Pathological agents such as ionizing radiation and oxidative free radicals can cause breaks in both strands of the DNA at a given site (double-strand break). This is the most serious type of DNA damage because neither strand is able to provide physical integrity or information content, as would be the case for single-strand DNA damage where one strand of the duplex remains intact. The repair of such breaks usually results in an irreversible alteration of the DNA. Two physiological forms of intentional double-strand (ds) DNA breakage and rejoining occur during lymphoid differentiation. One is V(D)J recombination occurring during early B and T cell development, and the other is class switch recombination, occurring exclusively in mature B cells. The manner in which physiological and most pathological double-strand DNA breaks are rejoined to restore chromosomal integrity are the same. Defects during the phases in which pathological or physiological breaks are generated or in which they are joined can result in chromosomal translocations or loss of genetic information at the site of breakage. Such events are the first step in some cancers and may be a key contributor to changes in DNA with age. Inherited defects in this process can result in severe combined immune deficiency. Hence, pathological and physiological DNA double-strand breaks are related to immune defects and cancer and may be one of the key ways in which DNA is damaged during aging.
Metropolitan Area Networks

As discussed in the introductory chapter of this book, the earliest need identified for a Metropolitan Area Network was to provide connectivity over an extended geography among devices connected to different Local Area Networks (see Figure 1.6). For this application, it was envisioned that the MAN would consist of a single high-speed multiple access channel, and that a single access station on each of the interconnected LANs would serve as that LAN’s gateway to its corresponding MAN access station. The traffic presented by a LAN to a MAN access station would be aggregated traffic, that is, time-multiplexed traffic generated by a multitude of devices connected to that LAN, needing to be transferred across the MAN to receivers connected to remote LANs. In effect, each LAN serves as a statistical multiplexer for locally generated traffic destined for other LANs, and this statistically multiplexed (or aggregated) traffic is the load presented to the MAN through each LAN’s corresponding MAN access station.
Estimating Sulfuryl Fluoride Emissions During Structural Fumigation of Residential Houses

The California Department of Pesticide Regulation conducted indoor air monitoring to estimate sulfury fluoride (SO2F2) emissions that bystanders around fumigated houses were potentially exposed to during structural fumigation of residential houses. Monitoring was conducted for 23 fumigations between September 2014 and March 2015. The SO2F2 indoor concentrations were measured from four locations inside the fumigated houses once an hour. The decreases of indoor concentrations are due to gas leakage (treatment period) and aeration (aeration period) from the structure to the outdoor environment. Analysis on the monitoring data showed considerable variability of half loss time (11–60 h) and mass loss (22–81%) during treatment periods. The decline of indoor concentrations followed the first-order kinetics; therefore, the hourly flux (g/m2s) of a treatment period can be calculated using initial SO2F2 concentration, treatment period mass loss, and house height. Although the California Aeration Plan requires a minimum 12–24 h of aeration after a treatment, the monitoring data showed that 93 ± 5% of the mass at the end of the treatment periods was emitted through the ducting system within the first 2 h. The average ratio of the loss amount in the first hour to the loss in the second was 6:1. These monitoring results provided the critical input for the computer modeling to estimate bystander exposure during structural fumigations of residential houses.
Correcting Fixed Effect Standard Errors When a Crossed Random Effect Was Ignored for Balanced and Unbalanced Designs

Previous studies have detailed the consequence of ignoring a level of clustering in multilevel models with straightly hierarchical structures and have proposed methods to adjust for the fixed effec...
A generalizable deep learning framework for localizing and characterizing acoustic emission sources in riveted metallic panels

Abstract This paper introduces a deep learning-based framework to localize and characterize acoustic emission (AE) sources in plate-like structures that have complex geometric features, such as doublers and rivet connections. Specifically, stacked autoencoders are pre-trained and utilized in a two-step approach that first localizes AE sources and then characterizes them. To achieve these tasks with only one AE sensor, the paper leverages the reverberation patterns, multimodal characteristics, and dispersive behavior of AE waveforms. The considered waveforms include AE sources near rivet connections, on the surface of the plate-like structure, and on its edges. After identifying AE sources that occur near rivet connections, the proposed framework classifies them into four source-to-rivet distance categories. In addition, the paper investigates the sensitivity of localization results to the number of sensors and compares their localization accuracy with the triangulation method as well as machine learning algorithms, including support vector machine (SVM) and shallow neural network. Moreover, the generalization of the deep learning approach is evaluated for typical scenarios in which the training and testing conditions are not identical. To train and test the performance of the proposed approach, Hsu-Nielsen pencil lead break tests were carried out on two identical aluminum panels with a riveted stiffener. The results demonstrate the effectiveness of the deep learning-based framework for single-sensor, AE-based structural health monitoring of plate-like structures.
Comparison and Outlook

In this chapter, we will compare the three discrete event simulation approaches, i.e., the traditional sequential DES, the synchronous PDES, and the out-of-order PDES, with a comprehensive set of experiments, and discuss their advantages and limitations [CHCD13].
The US Department of Energy’s high temperature reactor research and development program – Progress as of 2019

Abstract The modular high temperature reactor is a leading candidate for near-term deployment of an advanced reactor concept. The US Department of Energy supports the development of high temperature reactors through qualification of fuels, materials, and analysis methods that exploit the capabilities of the national laboratories (mainly Idaho, Oak Ridge, and Argonne) to generate the fundamental fuel, material, and core behavior data needed to support design and licensing efforts by vendors. Industrial vendors of high temperature reactor concepts provide input to the R&D program and engage in the design of the systems, structures, and components that are unique to their designs. Although there is considerable variation in the plant designs being developed, they all exploit the properties and behavior of the TRISO fuel, material, and analysis methods being tested in the DOE qualification programs. This paper summarizes the goals and recent progress of the Department of Energy’s Gas-Cooled Reactor research and development campaign and how it supports a wide variety of industrial efforts to deploy high temperature reactors to serve modern energy markets.
Accepted Safe Food-Handling Procedures Minimizes Microbial Contamination of Home-Prepared Blenderized Tube-Feeding.

Background The number of patients requiring home enteral nutrition (HEN) continues to increase. Many of these patients are interested in using blended food instead of, or in addition to, commercial enteral formula (CEF). Increased risk of food-borne illness is a concern of blenderized tube-feeding (BTF). This project assessed a standard procedure for minimizing bacterial growth of BTF prepared in the home setting. Methods Fifty participants prepared BTF in their kitchens using a standard preparation procedure to minimize bacterial contamination. BTF was assessed for growth of aerobic microorganisms, Escherichia coli, Staphylococcus aureus, and coliforms at baseline, 24-hour, and 48-hour intervals after preparation for a total of 150 colony forming units (CFU) counts performed. Results No sample had zero aerobic microbial counts; yet no substantial increase in microbial counts was observed during the 48 hours. At baseline and 24 hours, 5/50 (10%) had a CFU count of >104 , and at 48 hours, 6/50 (12%) exceeded 104 CFUs. Out of 150 CFU counts, 2 (1.3%) were just over 105 CFU/mL. Samples exceeding 104 CFU/mL were likely contaminated by common endospore-forming bacteria found in soil or by bacteria in milk that was close to its expiration date. Conclusion In this study, 88% of the samples met the US Food Code criteria for safe food consumption; 10.7% met guidelines for marginal safety by other standards; and 1.3% slightly exceeded 105 CFUs. Established safe food-handling procedures can minimize bacterial contamination of BTF and consequently reduce risk of food-borne infection in HEN patients.
Photorheology and Gelation during Polymerization of Coordinated Ionic Liquids

Ionic liquids (ILs) containing reactive groups provide a tunable medium for bulk polymerization and network formation with potential applications as 3D-printable materials. In this study, dynamic r...
Low-temperature growth of Al-doped ZnO by atomic layer deposition for plasmonics (Conference Presentation)

Transparent conducting oxides, such as Ga-doped ZnO (GZO) and Al-doped ZnO (AZO) are attractive materials for high-performance plasmonic devices operating at telecommunication wavelengths. In this contribution, we compare the growth of epsilon-near-zero GZO and AZO films on sapphire by two different deposition techniques: molecular beam epitaxy (MBE) and atomic layer deposition (ALD). For MBE of GZO, a multiple buffer consisted of a high-temperature MgO layer, a low-temperature ZnO, followed by a high-temperature ZnO layer is employed to assure the crystalline quality of the GZO film. By controlling the growth parameters, including Ga doping level, VI/II ratio, substrate temperature, we are able to produce GZO films at 350 °C with electron mobility between 30 and 50 cm2/V.s, electron concentration up to 7×1020 cm-3, and resistivity down to 2.5×10-4 Ω.cm. For ALD of AZO, without using any buffer, by reducing the Al pulse duration, we are able to grow the AZO films under a large ratio of Al to Zn pulses of 1:6, which improves the activation of Al as an effective dopant. Hence AZO films with electron concentration above 7×1020 cm-3, electron mobility between 10 and 20 cm2/V.s, and resistivity below 6×10-4 Ω.cm have been obtained at 250 °C. The corresponding epsilon-near-zero point in the ALD-grown material was tuned down to 1470 nm. Our data indicate that the ALD method provides a low-temperature route to plasmonic TCOs for telecommunication wavelength range. Effect of electron mobility on optical loss and, therefore, plasmonic figure of merit is discussed.
Becoming a ‘Cultural Destination of Choice’: lessons on vernacularization from Beirut and Buenos Aires

This article builds upon the concept of vernacularization as a way to better understand the circulation and implementation of global policy assemblages. The added value of a vernacularization appro...
Cybersecurity threats and experimental testbed for a generator system

In this work, a high-fidelity virtual testbed modeling a networked diesel generator, similar to those used commercially and by the military, is described. This testbed consists of a physical system...
Generalized Optimal SVPWM for the Switched- Capacitor Voltage Boost Converter

This paper presents a generalized space vector pulse width modulation SVPWM for the switched capacitor voltage boost converter. The algorithm is based on relaxing the location of the ON time interval within the sampling time. The four switching functions of the SC converter result in four variable that represent the location of the ON time inverter. The optimal solution of the four variable is obtained by using Monte Carlo simulation that is based on minimizing the harmonic distortion factor. Furthermore, the proposed algorithm allows seamless transition between the various SVPWM such as DPWMMAX, DPWMMIN, and regularly sampled SVPWM. The finding of this paper is presented in a form of MATLAB simulation results.
The Accumulation of Lender-Owned Homes During the U.S. Mortgage Crisis: Examining Metropolitan REO Inventories

A key concern among policymakers and community developers in recent years has been the extent to which lender-owned homes, often called real estate owned or “REO” properties accumulate in different local housing markets during the mortgage crisis. This paper describes the accumulation of REO properties in 356 metropolitan statistical areas (MSAs) from August 2006 to August 2008. It examines differences in both changes and static levels of REO activity across MSAs and compares changes in REO levels to changes in home values over the same period. Special attention is paid to twelve large MSAs with substantial levels of REO as of August 2008. A model of REO volume at the metropolitan level is estimated which includes differences in state foreclosure legal processes and timing among the independent variables. Finally, cluster analysis is used to identify a simple typology of MSAs based on REO levels and home price changes.
Asbestos in High-Risk Communities: Public Health Implications.

Asbestos-related diseases (ARDs)—mesothelioma, lung cancer, and asbestosis—are well known as occupational diseases. As industrial asbestos use is eliminated, ARDs within the general community from para-occupational, environmental, and natural exposures are more prominent. ARD clusters have been studied in communities including Broni, Italy; Libby, Montana; Wittenoom, Western Australia; Karain, Turkey; Ambler, Pennsylvania; and elsewhere. Community ARDs pose specific public health issues and challenges. Community exposure results in higher proportions of mesothelioma in women and a younger age distribution than occupational exposures. Exposure amount, age at exposure, fiber type, and genetic predisposition influence ARD expression; vulnerable groups include those with social and behavioral risk, exposure to extreme events, and genetic predispositions. To address community exposure, regulations should address all carcinogenic elongated mineral fibers. Banning asbestos mining, use, and importation will not reduce risks from asbestos already in place. Residents of high-risk communities are characteristically exposed through several pathways differing among communities. Administrative responsibility for controlling environmental exposures is more diffuse than for workplaces, complicated by diverse community attitudes to risk and prevention and legal complexity. The National Mesothelioma Registries help track the identification of communities at risk. High-risk communities need enhanced services for screening, diagnosis, treatment, and social and psychological support, including for retired asbestos workers. Legal settlements could help fund community programs. A focus on prevention, public health programs, particularization to specific community needs, and participation is recommended.
Environmental Geopolitics of Climate Engineering Proposals in the IPCC 5th Assessment Report

Environmental geopolitics offers an analytical approach that considers how environmental themes are brought into the service of geopolitical agendas. Of particular concern are claims about environment-related security and risk and the justification of actions (or inactions) proposed to deal with those claims. Environmental geopolitical analysis focuses on geographical knowledge and how that knowledge is generated and applied to stabilize specific understandings of the world. Climate engineering is a realm in which certain kinds of geographical knowledge, in the form of scientific interpretations of environmental interactions, are utilized to support a selective agenda that, despite claims about benefiting people and environments on a global scale, may be shown to reinforce uneven relationships of power as well as patterns of injustice. This paper focuses on how the IPCC AR5 discusses and portrays climate engineering. This particular conversation is significant, since the IPCC is widely recognized as reflecting current, international science and understanding of climate change processes and possible responses. We demonstrate an initial, environmental geopolitical analysis of this portrayal and discussion around climate engineering proposals by observing how the role and meaning of environmental features is limited, how human agency and impact in these scenarios is selective, and how insufficient attention is paid to spatial dimensions and impacts of these proposals. This paper contributes to a larger conversation about why it matters how we engage in discussion about climate impacts and issues; a central argument is that it is vital that we consider these proposed plans in terms of what they aim to secure, for whom, how and where.
Performance-based structural health monitoring through an innovative hybrid data interpretation framework

The utilization of Structural Health Monitoring (SHM) for performance-based evaluation of structural systems requires the integration of sensing with appropriate data interpretation algorithms to establish an expected performance related to damage or structural change. In this study, a hybrid data interpretation framework is proposed for the long-term performance assessment of structures by integrating two data analysis approaches: parametric (model-based, physics-based) and non-parametric (data-driven, model-free) approaches. The proposed framework employs a network of sensors through which the performance of the structure is evaluated and the corresponding maintenance action can be efficiently taken almost in real-time. The hybrid algorithm proposed can be categorized as a supervised classification algorithm. In the training phase of the algorithm, a Monte-Carlo simulation technique along with Moving Principal Component Analysis (MPCA) and hypothesis testing are employed for simulation, signal processing, and learning the underlying distribution, respectively. The proposed approach is demonstrated and its performance is evaluated through both analytical and experimental studies. The experimental study is performed using a laboratory structure (UCF 4-Span Bridge) instrumented with a Fiber Brag Grating (FBG) system developed in-house for collecting data under common bridge damage scenarios. The proposed hybrid approach holds potential to significantly enhance sensor network design, as well as continuous evaluation of the structural performance.
Geovisualization of Vegetation Patterns in National Parks of the Southeastern United States

Over the past ten years, the Center for Remote Sensing and Mapping Science (CRMS) at The University of Georgia has worked cooperatively with the National Park Service to create digital vegetation databases for 21 National Parks, Preserves, Home Sites and Battlefields in the southeastern United States. These databases were created from manually interpreted large-scale color infrared aerial photographs using a combination of Global Positioning System (GPS) surveys, softcopy photogrammetry and GIS modeling procedures. Throughout the process, geovisualization techniques have been used to aid in the extraction and assessment of vegetation patterns, quality control evaluation and communication of information to managers and users of park resources. In one example, three-dimensional (3D) drapes of orthorectified images and vegetation maps were used to aid in the interpretation process by providing the interpreter with multiple 3D perspective views and information on elevation range, slope and aspect. Upon completion of the databases, geovisualization techniques also were used to qualitatively identify and assess areas prone to errors in the geometric orthorectification. In this way, geovisualization contributed to improvements in both the thematic and geometric accuracy of the National Park Service vegetation data sets. In another example, animations of spatio-temporal data sets and 3D drapes were developed to assess the impacts of surrounding development and land use changes on resources within park boundaries. Geovisualizations provided to the National Park Service are being used to prioritize the acquisition of additional lands to help preserve water quality and habitats of ecological importance.
Health Promotion in Health Care Settings

Health care settings appear to be attractive sites for health promotion activities with patients. Providers and staff in these settings see a high volume of individuals, many of whom are at higher risk for disease or disability. Patients are also frequently seen on a recurrent basis, which provides opportunities for monitoring and reinforcing behavior modification. Patients also traditionally have given their provider essentially absolute authority over their health care so that recommendations from providers are a strong motivation for attempting behavior change. However, it is often necessary to intervene in health care settings in order to persuade and educate providers and staff to deliver prevention messages. Such interventions must disseminate health promotion information as well as proactively assist providers in changing professional practice patterns to include health promotion activities.
Nonenzymatic Browning in Fruit Products

Publisher Summary This chapter aims to present a critical review of the literature on browning in fruit products, to emphasize the deficiencies in the present knowledge, and thereby clarify the status of the problem. It discusses methods of color measurement. A general review of the problem of measuring color in canned foods has been made and the relative merits of using disc colorimeters and spectrophotometer to measure color are considered. The chapter discusses the effect of temperature on browning, which is the single most important factor in influencing the rate of browning in fruit products. The influence of temperature on the rate of browning in dried fruits has been studied and the effect of temperature on both browning and ascorbic acid content are considered. A further discussion of ascorbic acid losses in citrus products has been presented in the chapter. Attempts have been made to summarize the data by averaging the results obtained for all samples at each temperature, irrespective of the storage time; such averages are assumed to represent the change which occurs in the average storage time of the samples. The chapter discusses the effect of processing and drying temperature on browning, changes in chemical composition that accompany browning, and the use of inhibitors to delay browning. The influence of moisture, SO2 concentration, partial pressure of oxygen, and temperature on the rate of oxygen uptake by the fruit in relation to darkening is determined. A number of different experiments are made and the results have been summarized.
Motivation in the Science Classroom: Through a Lens of Equity and Social Justice

It is imperative that science teacher educators address strategies for motivating and enhancing the participation of traditionally underrepresented students in the STEM pipeline. Unfortunately, although there is a vast amount of research and literature on motivation in education, there are still gaps in the literature relative to motivating students from traditionally underrepresented and marginalized groups to participate in science. In an increasingly technological and global society, it is essential to address strategies that promote equity and social justice in science teaching in an effort to increase the achievement of students from traditionally underrepresented and marginalized groups in science, technology, engineering, and mathematics (STEM) areas. This chapter outlines effective strategies for motivating students in the science classroom.
Research Activities and Budget Allocations Among Federal Reserve Banks

Throughout the Federal Reserve System’s existence, economists have been interested in the process through which monetary policy decisions are formulated. For the most part, this decision-making process has been investigated from a ‘public interest’ perspective. Policy decisions are assumed to be a product of a procedure whereby officials gather information on the macro relations between money and different policy goals and then attempt to maximize a social welfare function based on these objectives. This approach stands in contrast to the economic theory of individual behavior and, in particular, to the recent extension of economic theory to the behavior of government bureaucrats.(1) In these cases an explicit utility-maximizing framework has been applied, somewhat successfully, to explain the budgetary outcomes of different bureaus.
Characterization of the RNase P RNA of Sulfolobus acidocaldarius.

Abstract RNase P is the ribonucleoprotein enzyme that cleaves precursor sequences from the 5' ends of pre-tRNAs. In Bacteria, the RNA subunit is the catalytic moiety. Eucaryal and archaeal RNase P activities copurify with RNAs, which have not been shown to be catalytic. We report here the analysis of the RNase P RNA from the thermoacidophilic archaeon Sulfolobus acidocaldarius. The holoenzyme was highly purified, and extracted RNA was used to identify the RNase P RNA gene. The nucleotide sequence of the gene was determined, and a secondary structure is proposed. The RNA was not observed to be catalytic by itself, but it nevertheless is similar in sequence and structure to bacterial RNase P RNA. The marked similarity of the RNase P RNA from S. acidocaldarius and that from Haloferax volcanii, the other known archael RNase P RNA, supports the coherence of Archaea as a phylogenetic domain.
Desfibrado de maderas obtenidas desde las oficinas salitreras de Humberstone y Santa Laura en Chile. Un sitio del patrimonio mundial.

En las oficinas salitreras de Humberstone y Santa Laura, declaradas Patrimonio de la Humanidad el ano 2005, se presenta un inusual proceso de deterioro en el que es posible observar fibras individuales en la superficie de la madera. En este trabajo se hizo una descripcion y evaluacion de los danos observados en las instalaciones pertenecientes a ambas oficinas. Asi mismo, se complemento el estudio mediante el analisis de las muestras recolectadas a traves microscopia electronica de barrido (SEM). Se realizaron estudios adicionales en las maderas, mediante la evaluacion de la velocidad de ultrasonido y extraccion de tornillo. Los resultados obtenidos determinaron que el deterioro evidenciado es de tipo quimico producto de la acumulacion de sales en las maderas, y cuyo efecto esta asociado con la degradacion de la lamela media altamente lignificada en maderas de las especies de Pseudotsuga menziesii y Nothofagus obliqua. Ademas, los resultados determinaron que la madera no afectada por la degradacion de la sal mantiene sus propiedades mecanicas inalteradas. El deterioro evidenciado, denominado desfibrado, se presenta en mayor o menor medida en la totalidad de las instalaciones. Sin embargo, el mayor dano se encontro en los pisos superiores de la torre de lixiviacion de Santa Laura, la que requiere de la aplicacion de medidas preventivas asociadas con la eliminacion de la sal presente en la superficie del material.
Chemical Tools to Study the Biology of Protein Arginine Phosphorylation

Reversible protein phosphorylation is a central mechanism of cellular signaling in both eukaryotes and prokaryotes. The major phosphoacceptor sites comprise serine, threonine and tyrosine residues....
Circuits and signal processing: accomplishments and future trends

Summary form only given. In 1915, the electric wave filter was introduced to meet the needs of the young communications industry. This was followed by the introduction of equalizer to compensate for the gain and phase distortion introduced by the transmission media. Soon, sophisticated techniques were developed to realize passive electrical networks capable to meeting the exacting performance demands of complex communication and control systems. Active network design became a fruitful area of investigation after the invention of the Audion and the introduction of the feedback amplifier. The first active filters naturally rose out of the wedding of the feedback amplifier with passive RLC networks. Since then, extensive research on the theory and practice of active networks, coupled with the growing availability of cheap, reliable, and small passive and active components, made the area of active networks one of the most attractive and promising branches of circuit theory. Signal processing, prior to the 1960s, was based primarily on continuous-time analog circuit technology. The rapid development of high-speed electronic digital computers, microelectronics, and integrated circuit fabrication technologies coupled with a number of major theoretical developments resulted in the use of digital techniques for signal processing and led to the field of digital signal processing.
Cellular Telephones and the National Sales Force

The cellular telephone has become a popular, worldwide business tool. The use of cellular telephones has been purported to increase productivity and boost responsiveness. In this paper, major issues in cellular telephone technology are presented. A case study which examines the process of adoption, implementation, and utilization of cellular telephones in a national sales force is presented. Managerial implications are discussed.
Pattern formation at liquid interfaces: II. The KI/chloral hydrate/starch system

Abstract Measurements are reported of pattern formation at a liquid interface produced by a photochemical reaction involving the system KI/chloral hydrate/ starch. The dependence of the wavelength on the concentrations of the reactants, the viscosity, and the height of the sample has been examined. It is concluded that the pattern is produced by a hydrodynamic mechanism.
ISOIMMUNIZATION ASSOCIATED WITH CESAREAN SECTION IN THE MOUSE.

M A T E R N h L isoimmunization associated with pregnancy in the mouse has been a subject of increased interest, partly because of its analogy to pregnancy isoimmunization in the human.lM3 We have previously shown that outcrossed female mice develop antibodies which react with paternal antigens carried by the offspring.3 Reported here is the further observation that delivery by cesarean section markedly increases the intensity and frequency of maternal isoimmunization in the mouse.
Antigen processing and presentation: How can a foreign antigen be recognized in a sea of self proteins?*

A mathematical model describing the time-dependent events of antigen processing and presentation is utilized to quantitatively analyze the importance of newly synthesized Ia molecules as well as Ia molecules internalized from the cell surface in the formation of Ia-antigen complexes, the T cell receptor ligand. It has recently been shown that antigen presenting cells are not selective for the proteins they process and present. Therefore, we also investigate the ability of macrophages and B cells to process and present antigen in the presence of competing proteins often present in the extracellular environment. A set of criteria is formulated based upon experimental data to determine the validity of two model variations. We draw two major conclusions from our simulations. First, we determine that macrophages and B cells can present between 1–3 Ia-antigen complexes μm −2 for antigen concentrations in the range of 4–7 μM while in the presence of approximately 0–10 μM competing proteins or peptides. Second, we find it likely that antigen presenting cells, both B cells and macrophages, need to internalize Ia molecules from the cell surface in order for a sufficient number of Ia-antigen complexes to be presented. Binding of antigen to newly synthesized Ia alone does not, given experimentally reported values for Ia synthesis, allow sufficient Ia-antigen complex formation.
Social factors related to syringe sharing among injecting partners: a focus on gender.

The study of social networks has become an increasingly utilized method of examining the relationship between injection drug users' social environment and risk of HIV. This study examined relational aspects of two injection drug users (IDUs) within a single social network as they relate to sharing syringes. Data presented in this study were derived from baseline interviews of 508 IDUs from Baltimore, MD. Analyses were performed separately for male and female participants in an effort to understand gender differences in social aspects of syringe sharing. Among this sample, women shared syringes with a significantly higher percentage of injecting partners compared to men. In separate multilevel logistic regression models, significant variables associated with males' and females' syringe sharing were: sharing drugs daily with female injecting partners, injecting partners' provision of drugs when indexes' were withdrawing, being sexual partners, and injecting partners' injecting speedballs. Factors associated...
Using a Cross Section to Train Veterinary Students To Visualize Anatomical Structures in Three Dimensions.

A cross section was used to enhance three-dimensional knowledge of anatomy of the canine head. All veterinary students in two successive classes (n = 124) dissected the head; experimental groups also identified structures on a cross section of the head. A test assessing spatial knowledge of the head generated 10 dependent variables from two administrations. The test had content validity and statistically significant interrater and test–retest reliability. A live-dog examination generated one additional dependent variable. Analysis of covariance controlling for performance on course examinations and quizzes revealed no treatment effect. Including spatial skill as a third covariate revealed a statistically significant effect of spatial skill on three dependent variables. Men initially had greater spatial skill than women, but spatial skills were equal after 8 months. A qualitative analysis showed the positive impact of this experience on participants. Suggestions for improvement and future research are discussed. © 2002 John Wiley & Sons, Inc. J Res Sci Teach 39: 10–34, 2002
Root cause evaluation of particulates in the lyophilized indomethacin sodium trihydrate plug for parenteral administration.

Abstract Particulate growth in parenteral product frequently results in product recalls causing drug shortages. While this is mostly attributed to quality issues in a firm, particulates growth could also be due to inadequate product, process, or environmental understanding. Therefore, the objective of this study was to use indomethacin sodium trihydrate (drug) as a model drug for lyophilization and evaluates short-term stability with respect to particulate growth at different storage temperatures. Under aseptic condition, each vial filled with filtered drug solution was lyophilized, and stoppered in LyoStar3. Crimped vials were kept at 5 °C, 15 °C, 25 °C, 25 °C/60%RH, and 40 °C/75%RH. At predefined time interval, samples were characterized using X-ray powder diffraction (XRPD), thermal, and spectroscopic method. Lyophilized formulation showed four thermal events: 60–90 °C demonstrating glass transition, 110–160 °C showing recrystallization exotherm,170–220 °C exhibiting endotherm of potential polymorph, and 250 °C showing melting endotherm. XRPD of the lyophilized powder demonstrated peak at 2 θ 11.10. Spectroscopic studies of lyophilized powder indicated alteration in symmetric and asymmetric carboxylate peaks over time indicating initiation of crystallization and crystal growth. Reconstitution studies indicated higher reconstitution time after six weeks for sample stored at 40 °C/75%RH. Furthermore, reconstituted solution showed presence of particulates after 8 weeks storage. These studies suggest that particulate growth can stem from poorly developed formulation and not necessarily due to frequently ascribed filtration issues.
Making the most of the magnetic and lattice entropy changes

Abstract Recent discoveries of novel materials exhibiting a magnetocaloric effect that is strongly enhanced by the magnetoelastic coupling—the so-called giant magnetocaloric effect materials—stimulated an unprecedented expansion of research related both to the fundamentals of the phenomenon and potential future applications of these materials in continuous magnetic cooling near room temperature. The subject of this work is twofold. On one hand, systems exhibiting the giant magnetocaloric effect may be prone to hysteresis, and may exist in nonequilibrium, phase-separated states, thus requiring a special care when their intrinsic physical properties are of interest. On the other hand, in order to harvest most of the magnetocaloric potential of a specific compound, both the magnetic and lattice degrees of freedom of the material must be precisely controlled.
An Amino Acid Change in the Exodomain of the E2 Protein of Sindbis Virus, Which Impairs the Release of Virus from Chicken Cells but Not From Mosquito Cells

Abstract In order to obtain a mutant of Sindbis virus (SV) with a low methionine-resistant (LMR) phenotype, i.e., able to replicate in methionine-deprived Aedes albopictus mosquito cells, standard SV (SV STD ) was passaged 17 times in mosquito cells maintained in a low methionine medium and then plaque-purified, also in mosquito cells. Although the virus obtained by this procedure, SV LM17 , did have the desired LMR phenotype, it also appeared to have acquired a host-range phenotype. We have now characterized the host-range phenotype of SV LM17 in greater detail. In yield assays, the titer of SV LM17 produced by chick embryo fibroblasts (CEF) was 100- to 1000-fold lower than that from mosquito cells. SV STD , in contrast, produced a similar titer of virus from the two cell types. On the other hand, when SV LM17 was assayed directly by plaque formation on CEF and on mosquito cell monolayers, no host restriction in CEF was observed. When CEF were infected with SV LM17 , viral proteins were synthesized normally, pE2 was processed to E2, and E2 was demonstrated by the fluorescent antibody method to reach the cell surface. However, electron microscopy of SV LM17 -infected cells revealed an absence of extracellular virions and of budding particles; also, nucleocapsids were not aligned beneath the plasma membrane. By sequence determination and by site-directed mutagenesis, it was determined that the host restriction of SV LM17 was due to a change from Ala to Val at position 251 of the E2 protein. Substitution of Gly or Leu at this position also resulted in the same host range phenotype.
Passive Control for Turbofan Tonal Noise

A three-dimensional linearized Euler model is developed for the interaction and scattering of unsteady incident disturbances by an annular cascade of unloaded blades. The model is first used to examine the validity of the popular two-dimensional strip theory for three-dimensional annular cascades at frequencies relevant to fan engine noise. It is then applied to investigate three methods of passive control for turbofan tonal noise, namely, blade lean, blade sweep, and mean flow acceleration. Because blade lean and sweep generally enhance the blade upwash radial phase variation, an analysis is carried out to examine the effects of the radial modulation of the incident disturbances on the annular cascade sectional lift and the modal acoustic response. Noise control by blade lean and sweep is then investigated for typical fans. The results show that blade lean or sweep can be designed to be effective noise reduction mechanisms; however, their effectiveness depends on the characteristics of the incident disturbances and the number of propagating duct modes. Converging ducts are also shown to be effective sound reduction mechanisms.
The plinian eruptions of 1912 at Novarupta, Katmai National Park, Alaska.

The three-day eruption at Novarupta in 1912 consisted of three discrete episodes. Episode I began with plinian dispersal of rhyolitic fallout (Layer A) and contemporaneous emplacement of rhyolitic ignimbrites and associated proximal veneers. The plinian column was sustained throughout most of the interval of ash flow generation, in spite of progressive increases in the proportions of dacitic and andesitic ejecta at the expense of rhyolite. Accordingly, plinian Layer B, which fell in unbroken continuity with purely rhyolitic Layer A, is zoned from >99% to ∼15% rhyolite and accumulated synchronously with emplacement of the correspondingly zoned ash flow sequence in Mageik Creek and the Valley of Ten Thousand Smokes (VTTS). Only the andesiterichest flow units that cap the flow sequence lack a widespread fallout equivalent, indicating that ignimbrite emplacement barely outlasted the plinian phase. On near-vent ridges, the passing ash flows left proximal ignimbrite veneers that share the compositional zonation of their valley-filling equivalents but exhibit evidence for turbulent deposition and recurrent scour. Episode II began after a break of a few hours and was dominated by plinian dispersal of dacitic Layers C and D, punctuated by minor proximal intraplinian flows and surges. After another break, dacitic Layers F and G resulted from a third plinian episode (III); intercalated with these proximally are thin intraplinian ignimbrites and several andesite-rich fall/flow layers. Both CD and FG were ejected from an inner vent <400 m wide (nested within that of Episode I), into which the rhyolitic lava dome (Novarupta) was still later extruded. Two finer-grained ash layers settled from composite regional dust clouds: Layer E, which accumulated during the D-F hiatus, includes a contribution from small contemporaneous ash flows; and Layer H settled after the main eruption was over. Both are distinct layers in and near the VTTS, but distally they merge with CD and FG, respectively; they are largely dacitic but include rhyolitic shards that erupted during Episode I and were kept aloft by atmospheric turbulence. Published models yield column heights of 23–26 km for A, 22–25 km for CD, and 17–23 km for FG; and peak mass eruption rates of 0.7–1x108, 0.6–2x108, and 0.2–0.4x108 kg s-1, respectively. Fallout volumes, adjusted to reflect calculated redistribution of rhyolitic glass shards, are 8.8 km3, 4.8 km3, and 3.4 km3 for Episodes I, II, and III. Microprobe analyses of glass show that as much as 0.4 km3 of rhyolitic glass shards from eruptive Episode I fell with CDE and 1.1 km3 with FGH. Most of the rhyolitic ash in the dacitic fallout layers fell far downwind (SE of the vent); near the rhyolite-dominated ignimbrite, however, nearly all of Layers E and H are dacitic, showing that the downwind rhyolitic ash is of ‘co-plinian’ rather than co-ignimbrite origin.
Vibrational spectra and ring-puckering of 2-cyclopenten-1-ones

Abstract The mid-infrared, far-infrared, and Raman spectra of 2-cyclopenten-1-one and 2-cyclopenten-1-one-5, 5-d2 have been recorded. Assignments for each of the thirty vibrational fundamentals have been made for the two molecules. Several ring-puckering transitions were observed in the far-infrared spectrum of each molecule. From these were determined potential functions which establish the planarity of the ring system. The potential functions in reduced form derived for the hyride and deuteride are V = 15.0(Z4 + 8.0Z2) cm−1 and V = 14.2(Z4 + 8.8Z2) cm−1, respectively.