cssi/SciSciGPT-SciSciNet huggingface dataset:
Conventional and autothermal pyrolysis of corn stover: Overcoming the processing challenges of high-ash agricultural residues

Abstract The high ash content of agricultural residues and other kinds of herbaceous biomass makes it a challenging feedstock for fast pyrolysis to bio-oil. Using corn stover as a representative feedstock, this study investigates fast pyrolysis of high ash, herbaceous biomass in a pilot-scale fluidized bed reactor using both conventional, nitrogen-blown and autothermal, air-blown operation. Initial efforts to pyrolyze corn stover were challenged by bed fouling, which prevented steady reactor operation. Substitution of coarser bed material allowed operation at higher superficial velocities, which promoted attrition and elutriation of recalcitrant biochar particles from the reactor. This resulted in dramatic improvement in stable reactor operation for both conventional and autothermal pyrolysis with bio-oil yields among the highest reported for pyrolysis of corn stover. The oxygen-to-biomass equivalence ratio required for autothermal operation was 6.8%. Autothermal operation also resulted in significant process intensification, increasing corn stover throughput from 7.8 kg hr−1 to 21.9 kg hr−1 for this 8.9 cm diameter reactor. Air-blown, autothermal operation did not significantly reduce bio-oil yield despite the presence of partial oxidation reactions. Carbon balances indicate carbon yields of biochar and aqueous, bio-oil light ends decreased by 18.5% and 4.7%, respectively, during autothermal pyrolysis compared to conventional pyrolysis while the more valuable, organic-rich heavy ends of the bio-oil were essentially preserved.
Examining the Relationship between Teacher Perceptions of Implementation of the SDLMI and Student Self-Determination Outcomes.

This study explored teacher perceptions of their ability to implement the Self-Determined Learning Model of Instruction (SDLMI) with fidelity and the impact of these perceptions on student self-det...
Impaired counterregulatory responses to hypoglycaemia following oral glucose in adults with cystic fibrosis.

The aim of this study was to determine the mechanism(s) for hypoglycaemia occurring late following oral glucose loading in patients with cystic fibrosis (CF). A 3 h 75 g OGTT was performed in 27 non-diabetic adults with CF who were classified based on this test as experiencing hypoglycaemia (glucose <3.3 mmol/l with or without symptoms or glucose <3.9 mmol/l with symptoms, n = 14) or not (n = 13). Beta cell function, incretin (glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic peptide [GIP]) and counterregulatory hormone responses (glucagon, catecholamines, growth hormone and cortisol) were assessed. The two groups did not differ in age, weight or BMI. There were more male participants and individuals with pancreatic exocrine insufficiency in the hypoglycaemia group. Fasting plasma glucose did not differ between the two groups (5.3 ± 0.16 vs 5.3 ± 0.10 mmol/l). Both fasting insulin (20.7 ± 2.9 vs 36.5 ± 4.8 pmol/l; p = 0.009) and C-peptide (0.38 ± 0.03 vs 0.56 ± 0.05 nmol/l; p = 0.002) were lower in those who experienced hypoglycaemia. Following glucose ingestion, glucose concentrations were significantly lower in the hypoglycaemia group from 135 min onwards, with a nadir of 3.2 ± 0.2 vs 4.8 ± 0.3 mmol/l at 180 min (p < 0.001). The test was terminated early in three participants because of a glucose level <2.5 mmol/l. Insulin and C-peptide concentrations were also lower in the hypoglycaemia group, while incretin hormone responses were not different. Modelling demonstrated that those experiencing hypoglycaemia were more insulin sensitive (439 ± 17.3 vs 398 ± 13.1 ml min−1 m−2, p = 0.074 based on values until 120 min [n = 14]; 512 ± 18.9 vs 438 ± 15.5 ml min−1 m−2, p = 0.006 based on values until 180 min [n = 11]). In line with their better insulin sensitivity, those experiencing hypoglycaemia had lower insulin secretion rates (ISRfasting: 50.8 ± 3.2 vs 74.0 ± 5.9 pmol min−1 m−2, p = 0.002; ISROGTT: 44.9 ± 5.0 vs 63.4 ± 5.2 nmol/m2, p = 0.018) and beta cell glucose sensitivity (47.4 ± 4.5 vs 79.2 ± 7.5 pmol min−1 m−2 [mmol/l]−1, p = 0.001). Despite the difference in glucose concentrations, there were no significant increases in glucagon, noradrenaline, cortisol or growth hormone levels. Adrenaline increased by only 66% and 61% above baseline at 165 and 180 min when glucose concentrations were 3.8 ± 0.2 and 3.2 ± 0.2 mmol/l, respectively. Hypoglycaemia occurring late during an OGTT in people with CF was not associated with the expected counterregulatory hormone response, which may be a consequence of more advanced pancreatic dysfunction/destruction.
Social annotation enabling collaboration for open learning

Collaboration is a conceptually ambiguous aspect of open education. Given inconsistent discussion about collaboration in the open education literature, this article suggests collaboration be define...
Learning to Lead Socially Just Schools: An Exploration of Candidate Readiness for Equity-Focused Principal Preparation in the United States.

In spite of concerted improvement efforts to improve curricula, many university-based principal preparation programmes in the United States do not explicitly attend to issues of equity or social ju...
The Effect of Ambient Temperature on Infectious Diarrhea and Diarrhea-like Illness in Wuxi, China.

Background The disease burden of infectious diarrhea cannot be underestimated. Its seasonal patterns indicate that weather patterns may play an important role and have an important effect on it. The objective of this study was to clarify the relationship between temperature and infectious diarrhea, and diarrhea-like illness. Methods Distributed lag non-linear model, which was based on the definition of a cross-basis, was used to examine the effect. Results Viral diarrhea usually had high incidence in autumn-winter and spring with a peak at -6°C; Norovirus circulated throughout the year with an insignificant peak at 8°C, while related bacteria usually tested positive in summer and peaked at 22°C. The lag-response curve of the proportion of diarrhea-like cases in outpatient and emergency cases revealed that at -6°C, with the lag days increasing, the proportion increased. Similar phenomena were observed at the beginning of the curves of virus and bacterial positive rate, showing that the risk increased as the lag days increased, peaking on days 16 and 9, respectively. The shape of lag-response curve of norovirus positive rate was different from others, presenting m-type, with 2 peaks on day 3 and day 18. Conclusion Weather patterns should be taken into account when developing surveillance programs and formulating relevant public health intervention strategies.
Impacts of Mode Mixity on Controlled Spalling of (100)-Oriented Germanium

Controlled spalling is a technology to prepare single-crystal thin films of semiconductors by fracture with a subsurface crack propagating nearly parallel to the substrate surface. Practical applications require uniform thickness and a smooth surface across the whole film. Both wafer-scale and patterned-stressor-defined small-area spalling of germanium substrates are conducted experimentally and numerically. River line features are observed on spalled surfaces close to lateral edges of the spall, regardless of the spall direction and the size of the spalled area. Three-dimensional finite element method modeling shows the river lines are caused by mixed mode I + III loading near the lateral edges of spall and predicts a spall depth variation near the lateral edges of spall due to mixed mode I + II loading. The absolute range of river lines increases with lateral size of spall, while the relative range of river lines decreases, consistent with variations in mode mixity.
The antigenic structure of tobacco mosaic virus.

Publisher Summary The chapter discusses on the antigenic structure of tobacco mosaic virus (TMV). Compared with other antigens, TMV is exceedingly large, yet not so large that the virus cannot be treated as if it were a soluble protein. The serological reactions of TMV are characteristic of those antigens, whose size places them between the small protein molecules, on one hand, and bacteria or cells, on the other. Thus, interactions of TMV with antibodies are somewhat unique and reveal a number of problems not apparent with either the smaller or larger antigens. For these reasons, the TMV anti-TMV reaction has attracted the attention of immunologists as well as virologists. TMV may dispense with its protein entirely, either as a result of chemical manipulation or mutation, and still retain its infectivity. But when protein is combined with the nucleic acid, it apparently plays some role in establishing the infection. At present, that role is unknown. As far as inactivation with antiserum is concerned, it is known; however, that antibody to the coat protein is without effect on the nucleic acid. Even after the whole virus is inactivated by antibody, the RNA within the rod retains its infectivity, for it can be extracted with phenol from the inactive precipitate with its original capacity for infection undiminished.
Routine Monitoring of the Electrocardiogram Q-T Interval in the EEG Laboratory

ABSTRACT.Patients with prolongation of the Q-T interval of the electrocardiogram are at risk for ventricular tachyarrhythmias which can lead to severe neurologic morbidity and mortality secondary to cerebral ischemia. Since these patients may present with seizures or syncope, they frequently receive their first diagnostic evaluation through the EEG laboratory. Electrocardiographic monitoring during an EEG examination is a simple and common practice but analysis for possible prolongation of the Q-T interval is not routinely performed. This paper discusses the importance and methodology of measuring the electrocardiogram Q-T interval on records obtained in the EEG laboratory.
Coronal Magnetic Field Context of Simple CMEs Inferred from Global Potential Field Models

Most work on coronal mass ejection (CME) interpretation focuses on the involved active region rather than on the large-scale coronal context. In this paper a global potential-field source-surface model of the coronal magnetic field is used to evaluate the sensitivity of the coronal field configuration to the location, orientation, and strength of a bipolar active region relative to a background polar field distribution. The results suggest that the introduction of antiparallel components between the field of the active region and the background field can cause significant topological changes in the large-scale coronal magnetic field resembling observations during some simple CMEs. Antiparallel components can be introduced in the real corona by the diffusion and convection of photospheric fields, flux emergence, or erupted or shear-induced twist of active-region fields. Global MHD models with time-dependent boundary conditions could easily test the stability of such configurations and the nature of any related transients.
Thalidomide and its dermatologic uses.

Abstract Thalidomide is a beneficial agent for treating a variety of refractory dermatologic disorders including erythema nodosom leprosum, lupus erythematosus, prurigo nodularis, actinic prurigo, pyoderma gangrenosum and aphthous stomatitis. Two thalidomide analogues, lenalidomide and CC-4047, are considerably more potent with decreased side effects when compared to thalidomide. They are currently undergoing trials and show promise, as they have increased immunomodulatory and anti-angiogenic activity. This category of medication and its use will be reviewed.
Making the Usage of STL Safe

The use of the C++ Standard Template Library has many advantages, but comes with a unique set of problems that have not been addressed by compilers or development tools. Many of these problems are due to misuses of the STL components and algorithms that are syntactically correct but semantically flawed. We motivate the case for the use of static analysis to diagnose such problems and describe our approach to checking STL usage with an STL-aware static analysis.
In vitro and in vivo Evaluation of a Shape Memory Polymer Foam-over-Wire Embolization Device Delivered in Saccular Aneurysm Models

Current endovascular therapies for intracranial saccular aneurysms result in high recurrence rates due to poor tissue healing, coil compaction, and aneurysm growth. We propose treatment of saccular aneurysms using shape memory polymer (SMP) foam to improve clinical outcomes. SMP foam-over-wire (FOW) embolization devices were delivered to in vitro and in vivo porcine saccular aneurysm models to evaluate device efficacy, aneurysm occlusion, and acute clotting. FOW devices demonstrated effective delivery and stable implantation in vitro. In vivo porcine aneurysms were successfully occluded using FOW devices with theoretical volume occlusion values greater than 72% and rapid, stable thrombus formation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1407-1415, 2016.
Preferential use of sonographically guided biopsy to minimize patient discomfort and procedure time in a percutaneous image-guided breast biopsy program.

OBJECTIVE To determine whether preferential use of sonographic guidance for percutaneous biopsy of breast masses results in a subset of patients with a shorter procedure time and less discomfort compared with patients undergoing stereotactic biopsy. METHODS A prospective observational study was performed on 193 women undergoing percutaneous image-guided breast biopsy between 1997 and 1999. Data were collected on room time, physician time, and patient comfort levels for 122 stereotactic and 71 sonographically guided biopsies. Differences between stereotactic and sonographically guided biopsy for all lesions and for masses were analyzed for statistical significance. RESULTS Mean room times were 62.2 minutes for stereotactic biopsy and 39.4 minutes for sonographically guided biopsy (P < .0001). Mean physician times were 23.0 minutes for stereotactic biopsy and 15.8 minutes for sonographically guided biopsy (P < .0001). When we limited our analyses to women undergoing biopsy for masses, the difference in physician time largely disappeared, but the difference in room time remained (P < .0001). Women undergoing stereotactic biopsy were more likely to report discomfort due to body positioning than were women undergoing sonographically guided biopsy (P < .001). These differences existed whether we included all lesions or restricted our analyses to masses. CONCLUSIONS Preferential use of sonographically guided breast biopsy for masses results in shorter procedure times and less patient discomfort compared with prone stereotactic biopsy.
Laboratory Assignments and Their Impact on Final Examination Grades: An Online Research Methods/Statistics Course1:

Over the last decade, enrollment in online courses has tripled. However, the delivery of online sections of courses that typically require laboratory work on campus can present a challenge. The pre...
A new homogeneous electrocatalyst for the reduction of carbon dioxide to methanol at low overpotential

Abstract The pyridinium ion is found to be a novel homogeneous catalyst for the reduction of CO 2 to methanol. Although the reduction of protons to dihydrogen competes with methanol formation, methanol faradaic yields of up to 30% have been observed at hydrogenated Pd electrodes. The former reaction occurs both directly at the electrode surface and also by the reduction of the reduced pyridinium species to form pyridine and hydrogen. The salient feature of this system is that the reduction of CO 2 proceeds at low overpotentials.
Robert M. LA Follette and the Insurgent Spirit

"Robert M. La Follette and the Insurgent Spirit" is a closely argued, lively, and readable biography of the central figure in the American Progressive movement. Wisconsin's Fighting Bob La Follette embodied the heart of Progressive sentiment and principle. He was a powerful force in shaping national political events between the eras of Populism and the New Deal"
Free Amino Acid Levels in Nicotiana glauca, N. Langsdorffii and Their Interspecific Hybrid Following Gamma Irradiation.

ABS>Two Nicotiana species and their species hybrid were subjected to varying dosages of gamma-irradiation for a period of two months. By the end of this period leaf abnormalities were evident in all dosages with the N. glauca parent, above 50 r per day in the hybrid and above 150 r per day in the N. langsdorffii parent. In general where leaf abnormalities occurred there was a concomitant increase in the free amino acid content of these leaves. Similarities, both morphological and physiological, to other organisms under stress conditions are discussed. (auth)
Free radical addition of F-alkyl compounds to unsaturated carboxylic anhydrides and their derivatives

Abstract Many perfluoroalkyl-substituted organic compounds have been obtained through free radical addition of F-alkyl iodides to a center of unsaturation: X, Y, and Z may include carbon chains, rings and various substituents. During the course of these synthetic studies—done over a span of several years—significant discoveries in mechanism and structure have been made. Today I wish to report some free radical additions of F-alkyl iodides to unsaturated anhydrides and their derivatives. Among the compounds recently discovered are the norbornene products 5 to 10. Spectroscopic properties of the adducts varied with position and nature of the substituents. Somewhat surprisingly, the chemical shift of protons on the R F side of the molecule was affected by changes in substituents on the other side of the molecule. Various reactions of the adducts were studied. Unusual stereospecificity in lactone formation and in base- induced cyclization to nortricyclene derivatives was observed. Only when the iodo group was in an endo position did these reactions occur. Analogous free radical addition of fluorinated thiols (R F CH 2 CH 2 SH) to norbornene anhydrides produced a series of 5-polyfluoroalkylthionorbornane-2,3-dicarboxylic acid anhydrides(11, 12; U S Patent 3,989,725 (1976). As in previous studies the entering group took up the exo position exclusively. Reaction with acids, esters or norbornene carboxylic imides of the fluorinated thiol also gave analogous products. Because of the hydrophobic nature of the F-alkyl groups the entire range of compounds displayed pronounced surface-activity and would appear to have utility in a wide range of applications.
High-Resolution NMR Probe for Experiments at High Pressures

Abstract A 300 MHz high-resolution, high-pressure NMR probe which operates in the pressure range of 1 bar to 9 kbar at temperatures of −30 to 100°C is described. Specialized novel design features of the probe are discussed and test spectra showing resolution better than 1 Hz ( −9 ) for 8 mm samples are presented. Potential biochemical applications of this probe are illustrated by experiments dealing with the pressure-induced unfolding of hen egg white lysozyme.
Assessment of Breath Sounds During Ambulance Transport

Abstract Study objective: To determine whether the environment of a moving ambulance affects the ability of out-of-hospital care providers to auscultate breath sounds. Methods: Out-of-hospital care providers assessed breath sounds with a previously described breath-sounds model in a quiet environment (control) and in a moving ambulance. The setting was a nonurban emergency medical services system and an interhospital transport agency based at a 600-plus-bed tertiary care center. The participants were physicians, transport nurses, and advanced life support EMS providers routinely involved in the emergency out-of-hospital treatment and transportation of the ill and injured. The accuracy with which participants identified the presence or absence of breath sounds in the two environments was compared with the use of the χ 2 test, with the α-value set at .05. Results: The accuracy of breath-sounds assessment in the control environment was 96% (251 of 260); the sensitivity was 96% and the specificity 97%. The accuracy of breath-sounds assessment in the experimental environment was 54% (140 of 260); the sensitivity was .09% and the specificity 98%. Participants were significantly less likely to hear breath sounds in the moving ambulance than in the quiet room ( P Conclusion: Assessment of breath sounds is hampered by the environment of a moving ambulance. [Brown LH, Gough JE, Bryan-Berg DM, Hunt RC: Assessment of breath sounds during ambulance transport. Ann Emerg Med February 1997;29:228-231.]
hp-version discontinuous Galerkin methods for hyperbolic conservation laws: A parallel adaptive strategy

This paper describes a parallel algorithm based on discontinuous hp-finite element approximations of linear, scalar, hyperbolic conservation laws. The paper focuses on the development of an effective parallel adaptive strategy for such problems. Numerical experiments suggest that these techniques are highly parallelizable and exponentially convergent, thereby yielding efficiency many times superior to conventional schemes for hyperbolic problems.
Eyes on the gulf

Collaboration between researchers and TACC's visualization staff to create timely visualizations of the oil spill during the time of the Deepwater Horizon disaster.
Some extensions of the innovations theorem

Consider an observed process that is the sum of a Wiener noise process and the integral of a not necessarily gaussian signal process. The innovations process is defined as the difference between the observed process and the integral of the causal minimum-mean-square-error estimate of the signal process. Then if the integral of the expected value of the absolute magnitude of the signal process is finite, we show that the innovations process is also a Wiener process. The present conditions are a substantial weakening of those previously used in which the integral of the signal variance had to be finite. The new result is obtained by using some recent results in martingale theory. These results also enable us to obtain similar results when the Wiener process is replaced by a square-integrable martingale.
Mechanische Stabilität von strukturierten Packungen

Seit Jahrzehnten sind die strukturierten Packungen aus Destillations- und Absorptionsprozessen nicht mehr wegzudenken. Verbesserungen in Kapazitat und Effizienz trugen zum Erfolg der strukturierten Packungen bei und sind auch heute noch Ziel weiterer Produktentwicklungen. Allerdings wird seither auch immer wieder die mechanische Stabilitat im Hinblick auf Langlebigkeit der Packung diskutiert und gefragt, wie hoch ein Packungsbett bei welcher Materialdicke gebaut werden konnte. Dieser Beitrag stellt Methoden vor, mit denen die mechanische Stabilitat von Packungen bestimmt werden kann, um so die Frage nach der moglichen Packungsbetthohe zu beantworten. For several years, structured packings are of high importance in distillation and absorption processes. Improvements in capacity and efficiency helped structured packings to their success and are still targets of current development work. However, always the question comes up for mechanical stability of structured packings and which packing bed height can be realized with a certain material type and material thickness. Two different methods are presented to measure the mechanical stability of structured packings and to answer that question.
A Cross-Validated Investigation of the Crumbaugh Purpose-in-Life Test

The Crumbaugh Purpose-in-Life test provides a measure of the extent to which an individual perceives life to be meaningful. As part of a larger study the scale was factor analyzed and then cross- validated with two similar samples of high school students. Al though assumed to be unidimensional, the test was found to contain two orthogonal dimensions: Despair and Enthusiasm. The test ap peared to be an excellent measure of adolescents' general attitudes toward life.
Diflunisal analogues stabilize the native state of transthyretin. Potent inhibition of amyloidogenesis.

Analogues of diflunisal, an FDA-approved nonsteroidal antiinflammatory drug (NSAID), were synthesized and evaluated as inhibitors of transthyretin (TTR) aggregation, including amyloid fibril formation. High inhibitory activity was observed for 26 of the compounds. Of those, eight exhibited excellent binding selectivity for TTR in human plasma (binding stoichiometry >0.50, with a theoretical maximum of 2.0 inhibitors bound per TTR tetramer). Biophysical studies reveal that these eight inhibitors dramatically slow tetramer dissociation (the rate-determining step of amyloidogenesis) over a duration of 168 h. This appears to be achieved through ground-state stabilization, which raises the kinetic barrier for tetramer dissociation. Kinetic stabilization of WT TTR by these eight inhibitors is further substantiated by the decreasing rate of amyloid fibril formation as a function of increasing inhibitor concentration (pH 4.4). X-ray cocrystal structures of the TTR·182 and TTR·202 complexes reveal that 18 and 20 b...
Non-isothermal melting of ice in the gas-diffusion layer of a proton-exchange-membrane fuel cell

Abstract Non-isothermal ice melting in the fibrous gas-diffusion layer (GDL) of a proton-exchange-membrane fuel cell (PEMFC) is investigated using differential scanning calorimetry (DSC). Non-isothermal ice-melting rates and ice-melting times are obtained from heat-flow measurements in water-saturated Toray GDLs at heating rates of 1, 2.5, 5, 10, and 25 K/min. In all cases, ice-melting times decrease nonlinearly with increasing heating rate. Nevertheless, melting temperatures remain at 272.9 ± 0.5 and 272.7 ± 0.4 K for bulk ice and ice within the GDL, respectively, reiterating that melting is thermodynamic-based at a rate limited by heat transfer. The slight GDL ice melting-point depression is consistent with the Gibbs–Thomson equation for equilibrium melting using an average pore diameter of 30 μm. Ice-melting endotherms are predicted from overall DSC energy balances coupled with a moving-boundary Stefan problem, where an ice-melting front within a GDL propagates with volume-averaged properties through an effective medium. Agreement between DSC experiment and theory is excellent. The proposed model accurately predicts ice-melting endotherms for Toray GDLs with two ice saturations and for bulk ice. Further, a pseudo-steady-state analysis obtains an analytical expression for ice-melting time, which is controlled by the time for heat addition to the propagating solid/liquid interface. Significantly, the new expression elucidates parameters controlling ice melting and allows for better design of both GDL materials and heating strategies to enhance the success of PEMFC cold-start.
New Ways of Managing Conflict

This article presents a review of the book “New Ways of Managing Conflict,” by Rensis Likert and Jane Gibson Likert.
The Occurrence of Phytophthora ramorum in Nursery Stock in California, Oregon, and Washington States

Abstract Data from nursery surveys conducted in 2003, 2004, and 2005 for ramorum blight and dieback caused by Phytophthora ramorum were analyzed to determine which plant cultivars were likely to be...
Thyroid function in experimental streptococcal pneumonia in the rat.

In order to study the effects of a severe bacterial infection on thyroid function rats were subjected to group A streptococcal pneumonia, and thyroid activity determined by measurement of the rate of discharge of I131 from the thyroid gland. Decreased thyroid activity of moderate to marked degree was observed in the majority of infected animals. Infected animals ate less than normal animals. Since fasting leads to decreased thyroid function, I131 release rates were measured in control animals pair-fed with infected animals and in control and infected animals force-fed a normal intake. The reduction in thyroid activity seen in acute infection was found to be partly but not entirely due to the associated voluntary food restriction. Although the adrenal glands of rats dying of pneumonia were very large, the thyroid inhibition occurring during the course of experimental pneumonia was not secondary to increased adrenocortical function since infected, adrenalectomized animals, receiving injections of cortisone, showed thyroid inhibition comparable to that observed in intact infected animals. The possible influence of the level of thyroid activity on resistance was evaluated. In two experiments a total of 80 rats in 3 groups was pretreated with propylthiouracil and injected daily with 3 dosage levels of 7-thyroxine for 3 weeks prior to inoculation. Under these conditions mortality rates in infected animals fell with decreasing levels of thyroid function. However, induced hypothyroidism was found to afford no protective effect in comparison with untreated infected animals.
Electro-analytical characterization of photovoltaic cells by combining voltammetry and impedance spectroscopy: voltage dependent parameters of a silicon solar cell under controlled illumination and temperature

This work reports a detailed electro-analytical framework for direct determination of a broad range of performance-indicator parameters of silicon solar cells. A mono-crystalline Si cell, equipped with the efficiency-boosting back surface field (BSF) feature, is used as a model system for this study. Independently controlled illumination (0–1 Sun, from a solar simulator) and temperature of the cell prevent the interference of photothermal and photovoltaic processes during the measurements. The technique of D.C. voltammetry is employed to obtain current–voltage plots, fill-factors, efficiencies and effective cell resistances. The same experimental platform also supports A.C. impedance spectroscopic probing of the solar cell, which, in combination with complex nonlinear least square analysis of the experimental data, provides detailed information about both the emitter–base and the BSF components of the photovoltaic device. These impedance measurements lead to straightforward determination of the diffusion and depletion layer capacitances, diode resistance, series resistance, concentration of majority carriers as well as lifetime of minority carriers in the base, resistance and capacitance of the BSF junction, and relaxation time of holes in the BSF. The results presented here demonstrate how relatively simple electro-analytical experiments can be strategically utilized for quantitative characterization of photovoltaic systems.
Admissibility Considerations in the Finite State Compound and Empirical Bayes Decision Problems

Summary In the compound decision problem the same decision problem. called the component decision problem, occurs repeatedly. Data from all repetitions are used to reach decisions concerning the parameter values in each component; such rules are called compound decision rules. The compound risk is the average risk across all component decisions. In the analogous empirical Bayes problem the parameters are taken to be independent and identically distributed with unknown distribution. This paper explores the relationship between compound risk admissibility and component risk admissibility in these problems. The definitions are general and the results are fairly obvious and proved for the finite parameter set component only.
Shrinking the period lengths of continued fractions while still capturing convergents

Abstract Here we prove that every real quadratic irrational α can be expressed as a periodic non-simple continued fraction having period length one. Moreover, we show that the sequence of rational numbers generated by successive truncations of this expansion is a sequence of convergents of α . We close with an application relating the structure of a quadratic α to its conjugate.
Cancer chemotherapeutics - angiogenesis agents: October 1999 - March 2000

Angiogenesis is often defined as the formation of capillary blood vessels from existing blood vessels. In the area of cancer research, approaches that seek to block angiogenesis are under intense investigation. In the past six months, a number of applications have appeared referring to small molecule inhibitors of matrix metalloproteinases (MMPs), the VEGF receptor tyrosine kinase, the integrin receptor αvβ3 and other defined targets. This review summarises the key features of these applications as well as other disclosures involving natural products claimed as angiogenesis inhibitors. The review also summarises angiogenesis-related disclosures involving endogenous inhibitors, novel targets and interesting technologies that have appeared in applications published between October 1999 and March 2000. If the patent activity is any indication, there is significant interest and a number of opportunities for treating cancer through inhibiting angiogenesis.
Looking at Losing: Presentations of the Media's Narrative of the Cleveland Browns’ Relocation

On November 6, 1995, Art Modell announced his intention to relocate the National Football League's (NFL) Cleveland Browns to Baltimore following the season. After 4 months of civic activism from Cleveland's community and legal action from the city's politicians, Cleveland, the NFL and Modell agreed to a deal that allowed the long-time owner to honour his contract with Baltimore and simultaneously provided a NFL club to Cleveland to begin play in 1999. This settlement was unique because it allowed Cleveland to retain the naming rights, colours, logo and, most significantly, the history of the Browns. Media presentations of Modell's announcement during the 4-month period illuminated a complex symbiotic relationship between the press, the public and sports entrepreneurs. The local media castigated and vilified Modell for betraying Cleveland's community and disturbing the city's supposed ‘renaissance’, while the national media connected with Cleveland as a leading member of the dilapidated ‘Rustbelt’ in the n...
Lagrangian heuristics for scheduling new product development projects in the pharmaceutical industry

To stay ahead of their competition, pharmaceutical firms must make effective use of their new product development (NPD) capabilities by efficiently allocating its analytical, clinical testing and manufacturing resources across various drug development projects. The resulting project scheduling problems involve coordinating hundreds of testing and manufacturing activities over a period of several quarters. Most conventional integer programming approaches are computationally impractical for problems of this size, while priority rule-driven heuristics seldom provide consistent solution quality. We propose a Lagrangian decomposition (LD) heuristic that exploits the special structure of these problems. Some resources (typically manpower) are shared across all on-going projects while others (typically equipment) are specific to individual project categories. Our objective function is a weighted discounted cost expressed in terms of activity completion times. The LD heuristics were subjected to a comprehensive experimental study based on typical operational instances. While the conventional "Reward---Risk" priority rule heuristic generates duality gaps between 47---58%, the best LD heuristic achieves duality gaps between 10---20%. The LD heuristics also yield makespan reductions of over 30% over the Reward---Risk priority rule.
A probability-based approach to VLSI circuit partitioning

Iterative-improvement 2-way min-cut partitioning is an important phase in most circuit partitioning tools. Most iterative improvement techniques for circuit netlists like the Fidducia-Mattheyses (FM) method compute the gains of nodes using local netlist information that is only concerned with the immediate improvement in the cutset. This can lead to misleading gain calculations. Krishnamurthy suggested a lookahead (LA) gain calculation method to ameliorate this situation; however, as we show, it leaves considerable room for improvement. We present here a probabilistic gain computation approach called PROP that is capable of capturing the global and future implications of moving a node at the current time. Experimental results show that for the same number of runs, PROP performs much better than FM (by about 30%) and LA (by about 27%), and is also better than many recent state-of-the-art clustering-based partitioners like EIG1, WINDOW, MELO and PARABOLI by 15% to 57%. We also show that the space and time complexities of PROP are very reasonable. Our empirical timing results reveal that it is appreciably faster than the above clustering-based techniques, and only a little slower than FM and LA, both of which are very fast.
Nicotine increases FosB expression within a subset of reward- and memory-related brain regions during both peri- and post-adolescence.

Periadolescent nicotine exposure is associated with increased consumption and rewarding properties of abused drugs. In the case of peri- but not post-adolescent animals, these effects are persistent and last to adulthood, suggesting that early nicotine treatment may alter postnatal CNS development in ways that contribute to long-term problems with drug abuse. To begin to identify brain regions that may be altered by developmental nicotine exposure, we have measured expression of a transcription factor, FosB, within a series of reward- and memory-related brain regions of Sprague–Dawley rats. FosB expression is known to acutely and cumulatively increase within a subset of brain regions, particularly nucleus accumbens, after exposure to many classes of abused drugs. Our results demonstrate that FosB is increased within nucleus accumbens and also the granule cell layer of hippocampal dentate gyrus after both peri- and post-adolescent nicotine exposure (0.4 mg kg−1 day−1 from days 34 to 43 and 60 to 69, respectively). In periadolescents, expression increases were detected 2 days after nicotine exposure, and persisted for weeks, through at least early adulthood at 80 days of age. In post-adolescents, expression increases persisted for at least 11 days to postnatal day 80. These findings demonstrate that nicotine treatment during both peri- and post-adolescence persistently alters activity of brain regions involved in reward and memory. Because this altered gene expression occurs after both peri- and post-adolescent treatment, it cannot be directly responsible for increased consumption and rewarding properties of abused drugs previously established to be distinctly associated with periadolescent nicotine exposure.
2-Substituted methyl α-d-galactopyranosides: Synthesis and binding affinity for the A and B subunits of the Griffonia simplicifolia I isolectins

Abstract The binding affinities of the N -acetyl, N -trifluoroacetyl, N -propionyl, N -formyl, N -benzoyl, N - p -nitrobenzoyl, N - p -aminobenzoyl, and N -methyl derivatives of methyl 2-amino-2-deoxy-α- d -galactopyranoside and the 2- O -acetyl, -benzoyl, -benzyl, and -methyl derivatives of methyl α- d -galactopyranoside for the A and B subunits of the Griffonia simplicifolia I isolectins have been determined by hapten inhibition analysis of a galactomannan-isolectin precipitation system. Models for these carbohydrate-protein interactions are presented together with an interpretation of the results on the basis of electronic and steric effects.
Mode of thyroxine action in the activation of glycogen synthetase of Rana catesbeiana tadpoles

Abstract Tadpole-liver glycogen synthetase, which is completely dependent on glucose 6-phosphate, is activated by insulin. Activation involves transformation of the enzyme to a form with a lower Km for substrate, UDPG. Several factors mimic the hormone and activate the enzyme to a similar degree. These include thyroxine, dibutyryl cyclic 3′,5′-adenylic acid, theophylline, puromycin and clucose. In all case studied so far, a series of events which leads to the release of insulin is initiated. By using alloxan-treated and pancreatectomized tadpoles, we have shown that thyroxine activation of glycogen synthetase requires functional pancreatic β-cells to produce insulin.
Instability in a combined heat and mass transfer problem in porous media

Abstract Exothermic chemical reactions can influence natural convection effects in a porous medium. Such phenomena may occur in tubular reactors, oxidation of solid material in large containers, chemical vapor deposition systems, liquid explosives, and others. Experimental evidence indicates that the influence of natural convection in many chemically reacting systems cannot be neglected. In the present work, transient effects of a two-dimensional convection generated and sustained by an endothermic chemical reaction and a constant heat flux are studied. The Darcy-Boussinesq equations are used to describe fluid flow through porous medium with different orders of chemical reaction ( n ). The complete mass, energy, and momentum balance equations are solved with the Arakawa-Dufort Frankel numerical scheme, which is particularly suitable for stationary solutions over a range of various parameters. Flow behavior is governed by several parameters, including thermal ( ra 1 ) and concentration ( Ra 2 ) Rayleigh numbers, Lewis number ( Le ), Peclet number ( Pe ), aspect ratio (α), and angle of inclination, ξ. The solution structure, i.e. the interconnections between the various branches appear quite complicated. Determination of linear stability on these solution branches reveal that all two-dimensional, stationary solutions develop some form of instability at different ranges of thermal or concentration Rayleigh numbers. The nature and frequency of these periodic solutions depend on the route followed in the parameter space of Ra 1 , Ra 2 , α, and ξ. The various routes to chaos are identified in this parameter space. A detailed study of frequency of oscillations and power spectrum reveals that instability in this system is reached through several routes. However, in most cases, determination of the dimension of chaotic attractors led to the assessment of chaotic flow, whereas frequency analysis detected clearly discernible spectral peaks with little frequency interlocking. This possible contradiction between Reulle-Takens instability with other more conventional approaches is highlighted in this paper. It is pointed out that instabilities due to simultaneous thermal and concentration effects may be unique. A complete stability map for different parameter spaces, e.g. Ra 1 and Ra 2 , ξ, α, and n is presented. Also presented in this map is the location of different types of instabilities, namely, periodic, quasi-periodic, and chaotic solutions.
The use of vanadium(II), manganese(II), and (cobalt(II) chlorides as packings to separate alkanes, alkenes, and alkynes by gas chromatography

Abstract The anhydrous chlorides of vanadium(II), manganese(II) and cobalt(II) were studied for possible use as packings in gas-solid chromatography. These compounds differ primarily in their number of available “3d” electrons, viz. V(II)(3d3), Mn(II)(3d5) and Co(II)(3d7). Various saturated and unsaturated organic compounds were investigated as adsorbates to observe the influence of varying π-electron densities. The heats of sorption were calculated and found to vary directly with the π-electron density of the adsorbate and vary inversely with the number of 3d electrons of the adsorbent. Separations achieved were a result of the π-electron density of the samples. Conjugated systems adsorbed on the salts were studied, but the column appeared to be best utilized for compounds having isolated π-bonds. A highly electronegative group, not near to a π-bond, appeared to have little effect on the degree of sorption. Although it was not our purpose to determine absolutely the mechanism of sorption, our data indicate that chemisorption plays a major role in the interaction between adsorbent and adsorbate.
Domain wall resonance in Ga substituted magnetoplumbite

Abstract DWR in thin plates of the hexaferrite PbFe12−xGaxO19 for x = 0,1 and 2 was measured with in-plane magnetic field, Hp, up to 13 kG. As the stripe period is smaller than thickness, the DWR frequency can be simply expressed analytically as a function of thickness, magnetization M, exchange constant, and uniaxial anisotropy energy. The dependence on Hp is incorporated in the dependence of the effective mass, z-component of magnetization Mz, and the wall energy on Hp. Very good agreement in obtained for both zero field resonance frequency (0.4 to 1.0 GHz) and the dependence of frequency on Hp.
DNA Ligase I and Proliferating Cell Nuclear Antigen Form a Functional Complex

DNA ligase I is responsible for joining Okazaki fragments during DNA replication. An additional proposed role for DNA ligase I is sealing nicks generated during excision repair. Previous studies have shown that there is a physical interaction between DNA ligase I and proliferating cell nuclear antigen (PCNA), another important component of DNA replication and repair. The results shown here indicate that human PCNA enhances the reaction rate of human DNA ligase I up to 5-fold. The stimulation is specific to DNA ligase I because T4 DNA ligase is not affected. Electrophoretic mobility shift assays indicate that PCNA improves the binding of DNA ligase I to the ligation site. Increasing the DNA ligase I concentration leads to a reduction in PCNA stimulation, consistent with PCNA-directed improvement of DNA ligase I binding to its DNA substrate. Two experiments show that PCNA is required to encircle duplex DNA to enhance DNA ligase I activity. Biotin-streptavidin conjugations at the ends of a linear substrate inhibit PCNA stimulation. PCNA cannot enhance ligation on a circular substrate without the addition of replication factor C, which is the protein responsible for loading PCNA onto duplex DNA. These results show that PCNA is responsible for the stable association of DNA ligase I to nicked duplex DNA.
Paleocene Lignite Deposits of Southwest Alabama: ABSTRACT

In southwest Alabama, lignite having economic potential occurs in the Oak Hill Member of the Naheola Formation. This middle Paleocene lignite generally consists of a single bed of 1-14 ft (0.5-4 m) in thickness and is the most extensive lignite in the southwest Alabama region. The Oak Hill lignite deposit accumulated in lower delta plain coastal marshes in interchannel areas behind a barrier system. The source area for the deltaic sediments was probably to the west and/or northwest of Choctaw County, Alabama. The lignite occurs in a clay-dominated sequence. Oak Hill interdistributary bay ripple-laminated clays are interbedded with ripple-laminated, crevasse splay sands generally less than 15 ft (5 m) thick. The glauconitic sands of the overlying Coal Bluff Marl Member of he Naheola Formation represent times of marine encroachment into the interchannel basin area. Lignite having subeconomic value at present occurs in the upper part of the Tuscahoma Sand. This upper Paleocene lignite is irregular in its outcrop pattern and apparently is not represented over extensive areas. It is locally persistent with one or more beds less than 3 ft (1 m) thick. The Tuscahoma may contain up to 6 lignite seams that may exceed a total thickness of 5 ft (1.5 m). These lignite beds were deposited in lower delta-plain coastal marshes adjacent to high constructive deltaic bar finger sands. Tuscahoma marsh clays are interbedded with ripple-laminated and cross-bedded bar finger sands. The Tuscahoma Sand is overlain by the Bashi Marl Member of the Hatchetigbee Formation. The Bashi contains a diverse lower Eocene marine fossil assemblage. End_of_Article - Last_Page 502------------