bluuebunny/crossref_metadata_2025 huggingface dataset:
Nyblade Receives 2012 Paul G. Silver Award for Outstanding Scientific Service: Response
Authors: Nyblade Andrew
Published: October 2013

I would like to thank Peter Shearer for his citation and the Seismology, Geodesy, and Tectonophysics sections for this honor. Paul Silver was a friend and mentor, and so receiving this award is especially meaningful. I first met Paul in 1993 when I was a postdoc writing a National Science Foundation proposal to deploy a seismic network in Tanzania and recall his strong encouragement to not cut back on the size of the project in spite of the cost. The project, which was funded, helped pave the way for the development of AfricaArray more than a decade later, illustrating Paul's far‐reaching influence on the community through his support of junior scientists.
Tsai Receives 2012 Keiiti Aki Young Scientist Award: Citation
Authors: Shearer Peter M.
Published: October 2013

Victor Tsai is the well‐deserved winner of the 2012 Keiiti Aki Young Scientist Award. He received his bachelor's degree from the California Institute of Technology, then went to Harvard for graduate school, where he received his Ph.D. in 2009. He did a Mendenhall postdoc at the U.S. Geological Survey in Golden, Colo., for 2 years, then returned to Caltech as an assistant professor last year. Victor has worked on an incredible range of topics, including the 2004 and 2012 Sumatra earthquakes, glacial earthquakes and more general problems of glacier physics, microseism generation and ambient noise cross‐correlation theory, river turbulence, and tsunami modeling. All of his research is elegant and theoretically rigorous. Victor has 26 papers to date, including 7 this year alone. He already has a substantial body of work, which promises an outstanding career.
Evaluating solutions to the faint young Sun problem
Authors: Balcerak Ernie
Published: October 2013

During the Archean eon, between about 3.8 billion years ago and 2.5 billion years ago, the Sun was about 20%–25% fainter than it is today. With less sunlight to warm the Earth, the oceans should have been frozen over, but geological evidence suggests that this was not the case.
Examining increasing potential for storms with global warming
Authors: Balcerak Ernie
Published: October 2013

Increases in convective available potential energy (CAPE)—the energy available to a parcel of air rising through a cloud—may increase the likelihood of severe storms. Model simulations have shown that global warming will increase CAPE in the tropics, but scientists do not fully understand why this occurs or what the implications may be for future precipitation intensity.
Fast atmosphere‐ocean model runs with large changes in CO2
Authors: Russell Gary L. , Lacis Andrew A. , Rind David H. , Colose Christopher , Opstbaum Roger F.
Published: October 2013

How does climate sensitivity vary with the magnitude of climate forcing? This question was investigated with the use of a modified coupled atmosphere‐ocean model, whose stability was improved so that the model would accommodate large radiative forcings yet be fast enough to reach rapid equilibrium. Experiments were performed in which atmospheric CO2 was multiplied by powers of 2, from 1/64 to 256 times the 1950 value. From 8 to 32 times, the 1950 CO2, climate sensitivity for doubling CO2 reaches 8°C due to increases in water vapor absorption and cloud top height and to reductions in low level cloud cover. As CO2 amount increases further, sensitivity drops as cloud cover and planetary albedo stabilize. No water vapor‐induced runaway greenhouse caused by increased CO2 was found for the range of CO2 examined. With CO2 at or below 1/8 of the 1950 value, runaway sea ice does occur as the planet cascades to a snowball Earth climate with fully ice covered oceans and global mean surface temperatures near −30°C.
Biomimetic Nanocomposites to Control Osteogenic Differentiation of Human Mesenchymal Stem Cells
Authors: Liao Susan , Nguyen Luong T. H. , Ngiam Michelle , Wang Charlene , Cheng Ziyuan , Chan Casey K. , Ramakrishna Seeram
Published: October 2013

The design of biomimetic nanomaterials that can directly influence the behavior of cells and facilitate the regeneration of tissues and organs has become an active area of research. Here, the production of materials based on nano‐hydroxyapatite composites in scaffolds with nanofibrous and nanoporous topographies, designed to mimic the native bone matrix for applications in bone tissue engineering, is reported. Human mesenchymal stem cells grown on these nanocomposites are stimulated to rapidly produce bone minerals in situ, even in the absence of osteogenic supplements in the cell‐culture medium. Nanocomposites comprising type I collagen and nano‐hydroxyapatite are found to be especially efficient at inducing mineralization. When subcutaneously implanted into nude mice, this biomimetic nanocomposite is able to form a new bone matrix within only two weeks. Furthermore, when the nanocomposite is enriched with human mesenchymal stem cells before implantation, development of the bone matrix is accelerated to within one week. To the best of the authors' knowledge, this study provides the first clear in vitro and in vivo demonstration of osteoinduction controlled by the material characteristics of a biomimetic nanocomposite. This approach can potentially facilitate the translation of de novo bone‐formation technologies to the clinic.
Vinyl ester resin: Rheological behaviors, curing kinetics, thermomechanical, and tensile properties
Authors: Zhang Xi , Bitaraf Vahid , Wei Suying , Guo Zhanhu , Zhang Xi , Wei Suying , Colorado Henry A.
Published: October 2013

The effects of isothermal temperature on the curing extent, gel time, dynamic rheological behaviors, and mechanical properties of vinyl ester resins (VERs) were systematically studied. Although, the curing extent was observed increase with increasing the operating temperature, the study of residual heat of cured VERs indicated that the final curing extent depended on the postcuring process. The values of shear storage and loss modulii at gel point were observed to decrease with increasing both the isothermal temperature and heating rate, which were associated with the formation of microgels during the gelation process. With increasing isothermal temperature and heating rate, the microgel did not have enough time to grow well, causing a reduced shear storage and loss modulii at the gel time. The storage and loss modulii of the cured VERs were also studied and shown that with temperature increased to the glass transition, both modulii were first decreased and then increased. © 2013 American Institute of Chemical Engineers AIChE J, 60: 266–274, 2014
Migration of additives toward the surface during aging of epoxy coating by infrared spectroscopy
Authors: Du Keli , Yang Guang , Yuan Zehong , Xu Wen , Liang Xiaofan
Published: October 2013

This research highlights the application of multi‐angle attenuated total reflection (ATR) infrared (IR) spectroscopy method in investigating the migration of additives from the bulk toward the surface which happens in the epoxy coating. Concentration profiles of additives such as low molecular polyamide 651 (LMPA 651) and 2,4,6 ‐ tris (dimethylaminomethyl) phenol (DMP‐30) were studied. Analysis of the shape of the additives concentration profiles revealed the existence of enrichment region and indicated the migration phenomenon of additives in epoxy coating during natural aging and accelerated aging processes. The changes of the additives concentration determined by the ATR‐IR method were consistent with the results obtained by FTIR analysis and gravimetric analysis. The result shows that the ATR‐IR method is very promising for investigating the surface chemical changes in epoxy coating due to its nondestructive testing, conveniency, and high efficiency. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40051.
Recent advances in applications of capillary electrophoresis with Fourier transform convolution: application to kinetic study of hydrolysis of hydrochlorothiazide
Authors: Maher Hadir M.
Published: October 2013

This manuscript discusses the application of chemometrics to the handling of capillary electrophoresis (CE) response data using the internal standard method. Derivative treatment (D method) of CE response data was used. Furthermore, convolution of the resulting derivative curves using discrete Fourier functions, the so‐called D/FF method, was applied. This approach is extremely beneficial where ideal baseline separation of electrophoretic peaks cannot be achieved, as in the case of drug isomers, structural related impurities or degradation products. The potential of these methods for resolving overlapping peaks was evaluated using the hydrolysis of hydrochlorothiazide (HCT) as an illustrative model. CE analysis was performed using a deactivated fused silica capillary (55 cm effective length and 75 µm i.d.), and background electrolyte solution consisted of phosphate buffer (20 mm, pH 8.0). Both chemometric methods allowed the determination of the intact drug (HCT) and its degraded form with high a degree of accuracy and precision. This was found to be beneficial in studying the degradation kinetics of hydrolysis of HCT at different temperatures. The corresponding pseudo‐first order rate constants and half‐lives were calculated. Finally, the proposed method made use of diode array detection as a tool for peak identity and purity confirmation. Copyright © 2013 John Wiley & Sons, Ltd.
An HPTLC method for quantification of cholesteryl esters from human plasma and rat liver microsomes
Authors: Gandhi Hardik , Pal Palash , Giridhar Rajani , Yadav Mange Ram
Published: October 2013

Cholesteryl oleate present as a neutral lipid in low‐density lipoprotein has been speculated to be a biomarker for atherosclerosis. Methods which are at hand for the quantification of cholesteryl oleate are either costly or entail the use of radioactive compounds. Charring of TLC plates has been used to identify cholesteryl esters for a long time but has never been applied to quantification of cholesteryl esters in biological matrices. Here, we report a novel method based on planar chromatography for the analysis of the products of the acyl CoA–cholesterol acyltransferase (ACAT) assay, viz. cholesteryl esters. Using silica gel 60 F254 as stationary phase, compounds were spotted on the plate and run using a solvent system comprising n‐hexane–diethyl ether–glacial acetic acid (90:10:1, v/v/v). The plates were developed by dipping in anisaldehyde–sulfuric acid reagent and were scanned at 546 nm for quantification. The developed method shows good linear relationship in the concentration range of 100–500 ng/band with a correlation coefficient (r) value of 0.9996. The method was validated for accuracy, precision and robustness. Percentage recovery of the method was found to be in the range 96.88–103.01% with intra‐ and inter‐day precision analysis yielding <2% relative standard deviation at nominal concentrations for analysis. The limits of detection and quantification were found to be 6.45 and 19.54 ng, respectively. The method was validated for robustness by making deliberate changes in mobile phase composition, volume and temperature of analysis, and the standard deviations of peak areas for these intentional changes were found to be 1.07, 1.02 and 1.30 respectively. The method was applied to the estimation of cholesteryl esters in plasma samples from patients diagnosed with hypercholesterolemia. No interferences were found from the biological matrices used in the assay. The proposed method could be of immense potential for estimation of cholesteryl oleate as a marker of ACAT activity, for screening of ACAT inhibitors in drug discovery process and in the prognosis of atherosclerosis. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of a Ni‐Based Catalyst on Bio‐Oil Upgrading under CO Atmosphere
Authors: Xu Q. , Zhang Z. , Yan Y.
Published: October 2013

A novel method of bio‐oil upgrading over Ni‐based catalysts under CO atmosphere and optimum conditions for a Ni/Cu/Zn/Al catalyst were determined. The oxygen content as well as the water content decreased significantly and the pH value of upgraded bio‐oil was higher than that of crude bio‐oil. The physical properties indicate that upgraded bio‐oil was more stable than crude bio‐oil.
Degradation of High Level m‐Cresol by Zinc Oxide as Photocatalyst
Authors: Abdollahi Yadollah , Zakaria Azmi , Sairi Nor Asrina
Published: October 2013

In this study, the high concentration of m‐cresol as a sample of organic pollutants was degraded in the presence of zinc oxide and UV irradiation during 6 h at laboratory scales. The amount of photocatalyst, pH and m‐cresol concentration were considered as effective factors on the photodegradation. The demineralization of m‐cresol was measured by UV–Vis spectrophotometry while the total organic carbon‐analyzer was used to determine the mineralization. The ultrahigh performance LC was used to identify probable intermediates. The results showed optimum condition at pH 7–9, which is the natural pH of industrial wastewater. Moreover, 100% of m‐cresol was removed after 5 h of irradiation time, which is quite significant. The detected intermediates were 3,5‐hydroxytoluene, 2,5‐hydroxy‐benzaldehyde, and 3‐hydroxy‐benzaldehyde after 3 h of reaction time. Reusability of the photocatalyst showed insignificant reduction in the photo‐catalytic performance. In conclusion, this investigation indicated high potential of zinc oxide suspension to remove high level concentration of m‐cresol under UV irradiation.
Analysis of AM‐2201 and metabolites in a drugs and driving case
Authors: Elian Albert A. , Hackett Jeffery
Published: October 2013

This case report describes the analysis of AM‐2201 in plant material and its metabolites in human urine obtained from an operator of a motor vehicle in the United States. The samples were taken from the driver because of his illegal driving activities and, his subsequent erratic behaviour. The AM‐2201 was extracted from a sample of plant material by sonicating it in methanol, after which an aliquot was taken and diluted with aqueous phosphate buffer (pH 6) and extracted by solid‐phase extraction using a C8/aminopropyl SPE cartridge. The cartridges were washed, dried, and eluted with ethyl acetate‐ methanol solvent system. The urine sample was hydrolyzed with β‐glucuronidase at pH 6.8 before being diluted with aqueous phosphate buffer (pH 6) and extracted with the same type of SPE cartridge. After evaporation of the eluates, the samples were dissolved in mobile phase for analysis by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Analysis of the plant material determined the concentration to be 0.05% (AM2201) by mass of dry material. The concentration of AM‐2201 (AM2201‐N‐(4‐hydroxypentyl ) metabolite in the urine was found to be 3.1 ng/ml. The urine also contained 109 ng/ml of delta‐9‐tetrahydrocannabinol carboxylic acid but no other drugs including JWH‐018 metabolites. Copyright © 2013 John Wiley & Sons, Ltd.
Aerobic Oxidation of Alcohols by Using a Completely Metal‐Free Catalytic System
Authors: Prebil Rok , Stavber Gaj , Stavber Stojan
Published: October 2013

A metal‐free reaction system of air, NH4NO3(cat), 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO)(cat), and H+(cat) is introduced as a simple, safe, inexpensive, efficient and chemoselective mediator for aerobic oxidation of various primary and secondary benzyl and alkyl alcohols, including those bearing oxidizable heteroatoms (N, S, O) to the corresponding aldehydes or ketones. Air oxygen under slight overpressure plays the role of the terminal oxidant, which is catalytically activated by redox cycles of nitrogen oxides released from a catalytic amount of NH4NO3 and cocatalyzed by TEMPO (nitroxyl radical compound), under acidic conditions, which are essential for an overall activation of the reaction system. The synthetic value of this reaction system and its green chemical profile was illustrated by a 10 g scale‐up experiment, performed in an open‐air system by using a renewable and reusable polymer‐supported form of TEMPO (OXYNITROX®S100). The reaction solvent was recovered by distillation under atmospheric pressure, and the pure final product was isolated under reduced pressure; the acid activators (HCl or H2SO4) were recovered as ammonium salts.
Influence of subaqueous processes on the construction and accumulation of an aeolian sand sheet
Authors: Basilici Giorgio , Dal' Bó Patrick Francisco Führ
Published: October 2013

In aeolian sand sheets the interaction between aeolian and subaqueous processes is considered one of the principal factors that controls this depositional environment. To examine the role played by the subaqueous processes on the construction and accumulation of sand sheets, surface deposits and subsurface sedimentary sections of a currently active aeolian sand sheet, located in the Upper Tulum Valley (Argentina), have been examined. On the sand sheet surface, airflows enable the construction of nabkhas, wind‐rippled mantles (flattened accumulations of sand forming wind ripples), megaripples, and small transverse dunes. Subaqueous deposits consist of sandy current ripples covered by muddy laminae. The latter are generated by annual widespread but low‐energy floods that emanate from the nearby mountains in the aftermath of episodes of heavy precipitations. Deposits of subaqueous origin constitute 5% of the accumulated sand sheet thickness.

The construction of the sand sheet is controlled by meteorological seasonal changes: the source area, the San Juan river alluvial fan, receives sediment by thaw‐waters in spring–summer; in fall–winter, when the water table lowers in the alluvial fan, the sediment is available for aeolian transport and construction of the sand sheet area. The flood events play an important role in enabling sand sheet accumulation: the muddy laminae serve to protect the underlying deposits from aeolian winnowing. Incipient cement of gypsum on the sand and vegetation cover acts as an additional stabilizing agent that promotes accumulation. Episodic and alternating events of erosion and sedimentation are considered the main reason for the absence of soils and palaeosols. Results from this study have enabled the development of a generic model with which to account for: (i) the influence of contemporaneous subaqueous processes on the construction and accumulation in recent and ancient sand sheets; and (ii) the absence of developed soils in this unstable topographic surface. Copyright © 2013 John Wiley & Sons, Ltd.
Quality of life impacts on 16‐year survival of an older ethnically diverse cohort
Authors: Gurland Barry , Teresi Jeanne A. , Eimicke Joseph P. , Maurer Mathew S. , Reid M. Carrington
Published: October 2013

Objective

The objective of this study is to examine the prediction of mortality, over 16 years, by the domains and domain elements underlying generic measures of quality of life (QoL).

Methods

The method used was an analysis of mortality in an older (65 + years) representative sample (N = 2130) of a multicultural community in North Manhattan. Five conventional QoL domains were measured by in‐home, rater‐administered, and computer‐assisted questionnaire: depressed mood, pain, self‐perceived health, and function and social relationships.

Results

Some domain scales that qualitatively express distress, such as depressed mood and widespread pain, significantly predicted lower mortality (were protective) and felt isolation trended in that direction, whereas domains indicating quantitative limitations such as impairment of functioning in daily tasks, stair climbing, as well as social disengagements and lack of support network significantly predicted higher mortality. Domain elements also mattered; contrary to their domain predictions, increased mortality was predicted by the domain elements of somatic symptoms of depression. Self‐perceived poor health reflected the predictive (higher mortality) direction of the limitations cluster.

Conclusions

The internal complexity of QoL is underscored by differential impacts of domains and elements on mortality. Clinical implications include setting distress domains as important clinical goals, whereas strengthening limiting domains could result in lengthening life and secondarily relieving distress. The relative weighting of these goals could be derived from patient preferences and clinical efficacy. Fundamental implications lie in the interaction between the person's qualitative evaluations of choices and the quantitative building of desired choices for a better QoL. Copyright © 2013 John Wiley & Sons, Ltd.
Inflamed benign tumors of the parotid gland: Diagnostic pitfalls from a potentially misleading entity
Authors: Mantsopoulos Konstantinos , Psychogios Georgios , Agaimy Abbas , Künzel Julian , Zenk Johannes , Iro Heinrich , Bohr Christopher
Published: October 2013

Background

The purpose of this study was to evaluate our experience in the diagnostic approach to inflamed benign tumors of the parotid gland at a single tertiary center.

Methods

A retrospective evaluation was carried out for all patients with signs of inflammation in the parotid gland on the ground of a benign parotid tumor, as confirmed by permanent histology.

Results

Sixteen patients were detected for our study. Histopathologic examination confirmed cystadenolymphoma in 11 cases (with metaplastic changes in 2 cases), 2 pleomorphic adenomas, 2 monomorphic adenomas, and 1 oncocytic cystadenoma. Diverse clinical signs (inflammation signs, facial palsy), ultrasound and MRI findings (poorly defined lesion margins), and the presence of squamous metaplastic changes on cytology often raised the suspicion of parotid malignancy or abscess.

Conclusion

In most cases, a high suspicion index combined with close monitoring of the patient may allow prompt and successful diagnosis and therapy. © 2014 Wiley Periodicals, Inc. Head Neck 37: 23–29, 2015
Immobilized ECM molecules and the effects of concentration and surface type on the control of NSC differentiation
Authors: Wilkinson Ashley E. , Kobelt Liza J. , Leipzig Nic D.
Published: October 2013

New developments in growth factor and pharmaceutical control of cells for neural regenerative strategies have built a need for high throughput assays to conveniently screen these treatments in vitro before moving to more complex experiments. Towards this application, we have studied an easy and highly reproducible culture regime with a renewable cell source for central nervous system (CNS) strategies. Adult neural stem cells (NSCs) derived from the CNS are attractive for use in screening assay because they are easily expanded and can differentiate into all major CNS cell types. NSCs were cultured on glass alone or methacrylamide chitosan (MAC) hydrogel coated glass substrates, immobilized with extracellular matrix (ECM) proteins collagen and laminin at varying densities. Proteins were also adsorbed on the surfaces as a control. We found that adsorbed protein on hydrogel coated glass resulted in the highest cell densities after 8 d, over twice the density of immobilized groups or adsorbed protein on glass. No significant differences were observed between collagen, laminin, or both proteins together regarding cell differentiation (p > 0.05); however, the morphological spreading and branching of differentiated NSC processes was enhanced on MAC substrates with covalently immobilized laminin protein. The results of this study suggest that a soft MAC hydrogel surface with adsorbed protein would be most desirable for specifying neuronal differentiation of large numbers of stem cells due to the high cellularities they supported. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3419–3428, 2014.
Development of polycaprolactone porous scaffolds by combining solvent casting, particulate leaching, and polymer leaching techniques for bone tissue engineering
Authors: Thadavirul Napapaphat , Pavasant Prasit , Supaphol Pitt
Published: October 2013

Sodium chloride and polyethylene glycol (PEG) were used as water‐soluble porogens for the formation of porous polycaprolactone (PCL) scaffolds. The main purpose was to prepare and evaluate in vitro efficacy of highly interconnected, three‐dimensional, porous polymeric scaffolds, as obtained from the combined particulate and polymer leaching techniques. Microscopic analysis confirmed the high interconnectivity of the pores and relatively uniform pore size of 378–435 μm. The PCL scaffolds were further characterized for their density and pore characteristics, water absorption and flow behaviors, and mechanical properties and the potential for their use as bone scaffolding materials was evaluated in vitro using mouse calvaria‐derived preosteoblastic cells (MC3T3‐E1). Evidently, the use of PEG as the secondary porogen not only improved the interconnectivity of the pore structures but also resulted in the PCL scaffolds that exhibited much better support for the proliferation and differentiation of the cultured bone cells. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3379–3392, 2014.
Exploration of Potential Tumor Markers for Lung Adenocarcinomas by Two‐Dimensional Gel Electrophoresis Coupled with Nano‐LC/MS/MS
Authors: Harn Horng‐Jyh , Chen Yi‐Lin , Lin Po‐Cheng , Cheng Yeung‐Leung , Lee Shin‐Chun , Chiou Tzyy‐Wen , Yang Hsueh‐Hui
Published: October 2013

To explore the potential tumor markers for lung adenocarcinoma, two‐dimensional gel electrophoresis (2DE) coupled with nano‐LC/MS/MS was used to analyze the differentially expressed proteins in 10 surgical resected lung adenocarcinoma tissues. 16 proteins were significantly different between the cancer tissue and adjacent normal tissue. Galectin‐1, peroxiredoxin II (Prx II), proapolipoprotein, glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH), aldolase A, enolase 1, neuropolypeptide h3, Prx V, cyclophilin A, vimentin, protein disulfide isomerase (PDI), tropomyosin 3 (TPM 3), glutathione S‐transferase Pi (GST‐Pi), manganese superoxide dismutase (MnSOD), and cofilin 1 were up‐regulated in the cancer tissue. On the other hand, profilin was down‐regulated in the cancer tissue. Among these proteins, six proteins were validated by Western blot analysis. The identified proteins contributing to the spectrum of cancer progression may be used as potential diagnostic biomarkers for lung adenocarcinomas.
Host (Nano Cage NaY)/Guest Mn(II), Co(II), Ni(II) and Cu(II) Complexes of N,N‐Bis(3,5‐Di‐Tert‐Butylsalicyidene)‐2,2‐Dimethyle‐1,3‐Diaminopropane: Synthesis and Catalyst Activity
Authors: Zendehdel M. , Khanmohamadi H. , Mokhtari M.
Published: October 2013

Mn(II), Co(II), Ni(II) and Cu(II) and N,N‐bis(3,5‐di‐tert‐butylsalicyidene)‐2,2‐dimethyle‐1,3‐diaminopropane complexes have been synthesized in Y zeolite cavity by the reaction of ion‐exchanged metal ions with the flexible ligand molecules. The host‐guest materials obtained have been characterized by elemental analysis, XRD, surface area, pore volume, TGA, FT‐IR and UV‐Vis techniques. Analysis of data indicates that formation of complexes in the pores Y zeolite without affecting the zeolite framework structure. Also, we report the oxidation of cyclohexanol catalyzed by host‐guest catalyst with tert‐buthyl hydrogen peroxide as oxygen donor. The activity of benzyl alcohol oxidation decreases in the series‐[Co(L)]/NaY > [Cu(L)]/NaY > [Mn(L)]/NaY > [Ni(L)]/NaY and the percent of product completely depend to catalyst. Zeolite complexes are stable enough to be reused and are suitable to be utilized as partial oxidation catalysts.
On the minimization of a certain convex function arising in applied decision theory
Authors: Ericson W. A.
Published: October 2013

The author, in an expository paper [4], has presented an algorithm for choosing a non‐negative vector

magnified image

to minimize the function

magnified image

subject to the constraint

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, where

magnified image

are given vectors and {\rm \vec M} is positive definite symmetric. In this paper a derivation of this algorithm is presented, including an exact solution in a degenerate case, only alluded to in [4], Several applications, in addition to that of [4], are briefly indicated.
On some sequencing problems
Authors: Szwarc Wlodzimierz
Published: October 2013

The (mxn) sequencing problem may be characterized as follows: There are m machines which can produce a piece consisting of n parts. Each part has a determined order in which it is processed through the machines. It is assumed that each machine cannot deal with more than one part at a time and that the processing required for each part can be accomplished only on one machine. That is, the machines are all specialized so that alternate machines for the same processing on a part is not possible. The problem is to find the best production plan consisting in sequencing the different parts so as to make the whole amount of time from the beginning of work till the piece is completed the shortest possible. Such a plan is called an optimum one. In the first 4 sections of this paper, the problem (2xn) is solved for the (2xn) case in which the order in which parts come on the machine is not constrained by further assumptions. The remainder of the paper then takes up: 1) the (3xn) problem of Bellman‐Johnson (viz. the technological processing order through the machine is the same for all parts) for several new special cases; 2) the 2xn problem of sequencing when delay times must also be considered; and, 3) some properties of an approximating method for solving (mxn) problems, including a delineation of cases when the approximating method will yield optimal solutions.
Schedule algebra: A progress report
Authors: Giffler Bernard
Published: October 2013

The following paper is the first part of a summary of the schedule algebraic method and its applications to date. It covers the origin and motivation of the schedule algebraic technique, the current status of the algebra as a mathematical system, and a brief outline of the theory of scheduling which the algebra is used to support. Part II of the Progress Report will be published at a later time. It will review applications of the algebra to practical problems and experience gained in the use of the algebra to schedule on‐going production systems.
Adaptive competitive decision in repeated play of a matrix game with uncertain entries
Authors: Sweat Calvin W.
Published: October 2013

This study is concerned with a game model involving repeated play of a matrix game with unknown entries; it is a two‐person, zero‐sum, infinite game of perfect recall. The entries of the matrix ((pij)) are selected according to a joint probability distribution known by both players and this unknown matrix is played repeatedly. If the pure strategy pair (i, j) is employed on day k, k = 1, 2, …, the maximizing player receives a discounted income of βk ‐ 1 Xij, where β is a constant, 0 ≤ β ⩽ 1, and Xij assumes the value one with probability pij or the value zero with probability 1 ‐ pij. After each trial, the players are informed of the triple (i, j, Xij) and retain this knowledge. The payoff to the maximizing player is the expected total discounted income.

It is shown that a solution exists, the value being characterized as the unique solution of a functional equation and optimal strategies consisting of locally optimal play in an auxiliary matrix determined by the past history.

A definition of an ϵ‐learning strategy pair is formulated and a theorem obtained exhibiting ϵ‐optimal strategies which are ϵ‐learning. The asymptotic behavior of the value is obtained as the discount tends to one.
Derivation and application of unit cost expressions perturbed by design changes
Authors: James Paul Meyer
Published: October 2013

Learning curves have been used extensively to predict future costs in the airframe and other industries. This paper deals with the effect of perturbations induced by design changes on the learning curves. Equations that are developed and applied make it possible to predict future costs accurately in a perturbed environment. The formulations can be used effectively in EDP programs.
On maximization of the integral of a bell‐shaped function over a symmetric set
Authors: Gilliland Dennis C.
Published: October 2013

Given a target T in Euclidean n‐space Rn and a point bomb whose point of impact in Rn is governed by a probability distribution about the aim point a, what choice of a maximizes the probability of a hit va(T)? Of course, only in special cases is an exact solution of this problem obtainable. This paper treats targets T which are symmetric about the origin o and demonstrates conditions on the extent of T and the impact density f, a density with respect to Lebesgue measure, sufficient for va(T) to be monotone in the distance from a to o and maximized at a = o. The results are applied to various tactical situations.
On the theory of semi‐infinite programming and a generalization of the kuhn‐tucker saddle point theorem for arbitrary convex functions
Authors: Charnes A. , Cooper W. W. , Kortanek K. O.
Published: October 2013

We first present a survey on the theory of semi‐infinite programming as a generalization of linear programming and convex duality theory. By the pairing of a finite dimensional vector space over an arbitrarily ordered field with a generalized finite sequence space, the major theorems of linear programming are generalized. When applied to Euclidean spaces, semi‐infinite programming theory yields a dual theorem associating as dual problems minimization of an arbitrary convex function over an arbitrary convex set in n‐space with maximization of a linear function in non‐negative variables of a generalized finite sequence space subject to a finite system of linear equations.

We then present a new generalization of the Kuhn‐Tucker saddle‐point equivalence theorem for arbitrary convex functions in n‐space where differentiability is no longer assumed.
On two nonprobabilistic utility measures for weapon systems
Authors: Enzer Hermann
Published: October 2013

In this paper an attempt is made to derive two interval utility measures for public goods. The domain of the measures is partitioned into priority classes in such a way that each class contains an element, called a kernel, which can be moved by parameter variation to the immediately preceding class. The “expansion path” from priority class to priority class is determined by an optimality criterion. The measures themselves are based on optimality conditions that are similar to the familiar first‐order conditions of consumer analysis. One is a product measure and the other one is additive.
Inventory control of by‐products
Authors: Evans Richard V.
Published: October 2013

The system to be controlled produces n products simultaneously in fixed proportions every time it is activated. Demands for the products in any period are components of an n dimensional vector random variable with known distribution function. Cases of excess demands backlogged and excess demands lost are considered. In the former the notion of k convexity can be generalized to guarantee relatively simple form for the optimal policy in an n decision problem. In the latter, this generalization was not successful although when there is no setup cost, a convexity argument can be used to show that the optimal policy has a simple form.
Problems in life cycle support cost estimation
Authors: Goldman A. S.
Published: October 2013

Although industry is expected to design hardware to fit into a general support system and to be capable of arguing life‐cycle system costs, adequate information has not been available on the support system in terms of policies and operating decision rules. Policies and operating decisions by users dominate engineering design decisions in determining life‐cycle support costs. The relative effect of each of these decision areas on support costs has yet to be resolved empirically. Without an understanding of the sensitivity of support costs to alternative designs, capability is limited in design improvement and support of end items. Life‐cycle costing of analysis under cost‐effectiveness and the maintainability of integrated logistics support is open to question.
Bayes sequential design of stock levels
Authors: Zacks S.
Published: October 2013

Bayesian determination of optimal stock levels is studied for the case of Poisson distribution of the demand variable, and prior gamma distribution of the expected demand. Bayes sequential procedure is derived, assuming that stock level can be adjusted at the beginning of each period so that a shortage can be immediately replenished and an overstock can be corrected. The Bayes sequential procedure is more difficult to obtain if this assumption is removed. A dynamic programming method for obtaining the general Bayes sequential procedure is outlined. Finally, an empiric Bayes estimation procedure of the optimal Bayesian stock level is presented.
A branch and bound algorithm for allocation problems in which constraint coefficients depend upon decision variables
Authors: Gross Donald , Soland Richard M.
Published: October 2013

A branch and bound algorithm is developed for a class of allocation problems in which some constraint coefficients depend on the values of certain of the decision variables. Were it not for these dependencies, the problems could be solved by linear programming. The algorithm is developed in terms of a strategic deployment problem in which it is desired to find a least‐cost transportation fleet, subject to constraints on men/materiel requirements in the event of certain hypothesized contingencies. Among the transportation vehicles available for selection are aircraft which exhibit the characteristic that the amount of goods deliverable by an aircraft on a particular route in a given time period (called aircraft productivity and measured in kilotons/aircraft/month) depends on the ratio of type 1 to type 2 aircraft used on that particular route. A model is formulated in which these relationships are first approximated by piecewise linear functions. A branch and bound algorithm for solving the resultant nonlinear problem is then presented; the algorithm solves a sequence of linear programming problems. The algorithm is illustrated by a sample problem and comments concerning its practicality are made.
A test for the hypothesis that two extreme‐value scale parameters are equal
Authors: Mann Nancy R.
Published: October 2013

A statistic is determined for testing the hypothesis of equality for scale parameters from two populations, each of which has the first asymptotic distribution of smallest (extreme) values. The probability distribution is derived for this statistic, and critical values are determined and given in tabular form for a one‐sided or two‐sided alternative, for censored samples of size n1 and n2, n1 = 2, 3, …. 6, n2 = 2, 3, …. 6. The power function of the test for certain alternatives is also calculated and listed in each case considered.
A demand prediction technique for items in military inventory systems
Authors: Haber Sheldon E. , Sitgreaves Rosedith , Solomon Henry
Published: October 2013

A brief description of a new general approach to demand prediction problems is given. This is based on the demand characteristics of parent components and the parts installed in these components. A specific model is presented which employs this information. The paper concludes with empirical tests of the model.
The discrete max‐min problem
Authors: Randolph P. H. , Swinson G. E.
Published: October 2013

The historic max‐min problem is examined as a discrete process rather than in its more usual continuous mode. Since the practical application of the max‐min model usually involves discrete objects such as ballistic missiles, the discrete formulation of the problem seems quite appropriate. This paper uses an illegal modification to the dynamic programming process to obtain an upper bound to the max‐min value. Then a second but legal application of dynamic programming to the minimization part of the problem for a fixed maximizing vector will give a lower bound to the max‐min value. Concepts of optimal stopping rules may be applied to indicate when sufficiently near optimal solutions have been obtained.
Optimum quantiles for the linear estimation of the parameters of the extreme value distribution in complete and censored samples
Authors: Chan Lai K. , Kabir A. B. M. Lutful
Published: October 2013

The present study is concerned with the determination of a few observations from a sufficiently large complete or censored sample from the extreme value distribution with location and scale parameters μ and σ, respectively, such that the asymptotically best linear unbiased estimators (ABLUE) of the parameters in Ref. [24] yield high efficiencies among other choices of the same number of observations. (All efficiencies considered are relative to the Cramér‐Rao lower bounds for regular unbiased estimators.) The study is on the asymptotic theory and under Type II censoring scheme.

For the estimation of μ when σ is known, it has been proved that there exists a unique optimum spacing whether the sample is complete, right censored, left censored, or doubly censored. Several tables are prepared to aid in the numerical computation of the estimates as well as to furnish their efficiencies.

For the estimation of σ when μ is known, it has been observed that there does not exist a unique optimum spacing. Accordingly we have obtained a spacing based on a complete sample which yields high efficiency. A similar table as above is prepared.

When both μ and σ are unknown, we have considered four different spacings based on a complete sample and chosen the one yielding highest efficiency. A table of the efficiencies is also prepared.

Finally we apply the above results for the estimation of the scale and/or shape parameters of the Weibull distribution.
Optimal policies under the shortage probability criterion for an inventory model with unknown dependent demands
Authors: Iglehart Donald L. , Jaquette Stratton C.
Published: October 2013

The principal innovation in this paper is the consideration of a new objective function for inventory models which we call the shortage probability criterion. Under this criterion we seek to minimize the total expected discounted cost of ordering subject to the probability that the stock level at the end of the period being less than some fixed quantity not exceed some prescribed number. For three different models we show that the minimum order policy is optimal. This result is then applied to a particular inventory model in which the demand distribution is not completely known. A Bayesian procedure is discussed for obtaining optimal policies.
On the equivalence between the Node‐ARC and ARC‐Chain formulations for the multi‐commodity maximal flow problem
Authors: Jarvis John J.
Published: October 2013

The purpose of this article is to formulate the multi‐commodity maximal flow problem into a node‐arc form and to show that when decomposition is applied to this form the resulting master and subproblems become precisely those described by Ford & Fulkerson [3] using the arc‐chain formulation. A generalization to the problem is then considered which can potentially speed its convergence.
Applications of a generalized combinatorial problem of smirnov
Authors: Alter Ronald , Lientz B. P.
Published: October 2013

In this paper applications of results obtained by these authors for a generalized version of a problem proposed by Smirnov, are considered. The areas of application explored are system interface, queueing, transportation flow, and sequential analysis. The included table should be invaluable to the reader in applying these results. Finally the relationship between the limiting and exact expressions relating to this table is also explored.
An algorithm (GIPC2) for solving integer programming problems with separable nonlinear objective functions
Authors: Pegden Claude Dennis , Petersen Clifford C.
Published: October 2013

This paper presents an algorithm for solving the integer programming problem possessing a separable nonlinear objective function subject to linear constraints. The method is based on a generalization of the Balas implicit enumeration scheme. Computational experience is given for a set of seventeen linear and seventeen nonlinear test problems. The results indicate that the algorithm can solve the nonlinear integer programming problem in roughly the equivalent time required to solve the linear integer programming problem of similar size with existing algorithms. Although the algorithm is specifically designed to solve the nonlinear problem, the results indicate that the algorithm compares favorably with the Branch and Bound algorithm in the solution of linear integer programming problems.
On the existence of joint production functions
Authors: Al‐Ayat Rokaya , Färe Rolf
Published: October 2013

Within a general framework of production correspondences satisfying a set of weak axioms necessary and sufficient conditions for the existence of a joint production function are given. Without enforcing the strong disposability of inputs or outputs it is shown that a joint production function exists if and only if both input and output correspondences are strictly increasing along rays.
The search for an intelligent evader concealed in one of an arbitrary number of regions
Authors: Gittins J.C. , Roberts D.M.
Published: October 2013

This paper considers the search for an evader concealed in one of an arbitrary number of regions, each of which is characterized by its detection probability. We shall be concerned here with the double‐sided problem in which the evader chooses this probability secretly, although he may not subsequently move; his aim is to maximize the expected time to detection, while the searcher attempts to minimize it.

The situation where two regions are involved has been studied previously and reported on recently. This paper represents a continuation of this analysis. It is normally true that as the number of regions increases, optimal strategies for both searcher and evader are progressively more difficult to determine precisely. However it will be shown that, generally, satisfactory approximations to each are almost as easily derived as in the two region problem, and that the accuracy of such approximations is essentially independent of the number of regions. This means that so far as the evader is concerned, characteristics of the two‐region problem may be used to assess the accuracy of such approximate strategies for problems of more than two regions.
The sensitivity of first term navy reenlistment to changes in unemployment and relative wages
Authors: Cohen Les , Reedy Diane Erickson
Published: October 2013

Multiple regression analysis was used to analyze newly developed twenty year time series of first term reenlistment rates for nine major Navy occupational categories. Results indicate that there are significant differences among the occupational categories in the determinants of their reenlistment behavior. More importantly, it is apparent that reenlistment rates are highly sensitive to current unemployment and especially unemployment about the time of enlistment. By comparison, relative wages (measures of military versus private sector rates of compensation) are relatively insignificant and appear powerless to control reenlistment in the context of normal fluctuations in economic activity.