bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of a Non-Ionic Surfactant on Soils: A Model Study
Authors: Xue Xiaobo , Zhou Yanmei , Wang Dongshen
Published: December 2006

The adsorption of the widely used non-ionic surfactant Triton X-100 (TX) onto three model inorganic soil components (silica powder, γ-alumina and calcite) was investigated in a series of batch experiments in which the aqueous phase was equilibrated with the solid under different solution conditions. TX showed no discernable adsorption onto γ-alumina over the pH range 3.8 < pH < 12.1 and a temperature of 15°C or onto calcite at the same temperature and pH range 7.7 < pH < 11.7. However, significant and reversible adsorption from solutions was found for silica powder suspensions.

The adsorption isotherms obtained for TX uptake onto silica powder were best fitted by the Freundlich model. An increase in the ionic strength of the electrolytic solution led to a decrease in the surface concentration of TX on silica powder, indicating significant electrostatic interactions between TX and silica powder particles, possibly through interaction with the surface silanol groups of the solid substrate. Increasing the pH value of the electrolyte solution from 6 to 9 led to a considerably decrease in the amount of TX adsorbed, while a decrease in the solution pH from 6 to 3 had only a slight effect on the surface concentration of adsorbed TX. The adsorption of TX onto silica powder decreased as the temperature was increased in the range 15–45°C, indicating that the adsorption process was exothermic. The magnitude of the calculated enthalpy of adsorption (ca. 10 kJ/mol) demonstrated that the uptake at the solid/liquid interface at an equilibrium pH of 6.1 was largely due to physisorption.
Removal of Lead(II) Ions from Aqueous Solutions Using a Modified Cellulose Adsorbent
Authors: O'Connell David W. , Birkinshaw Colin , O'Dwyer Thomas F.
Published: December 2006

A series of adsorption studies were carried out on a glycidyl methacrylate-modified cellulose material functionalised with imidazole (cellulose–g-GMA-imidazole) to assess its capacity towards the removal of Pb(II) ions from aqueous solution. The study sought to establish the effect of a number of parameters on the removal of Pb(II) ions from solution by the cellulose–g-GMA-imidazole. The effect of initial metal concentration, contact time and solution temperature on the removal of Pb(II) ions from solution by the cellulose–g-GMA-imidazole was assessed. Cellulose–g-GMA-imidazole sorbent showed an uptake of ca. 72 mg/g of Pb(II) ions from aqueous solution at 23°C. The adsorption process is best described by the Langmuir adsorption model and the thermodynamics of the process suggest that the binding process is exothermic. The kinetics of the adsorption process indicated that the uptake of Pb(II) ions occurred within 40 min and that pseudo-second-order kinetics best describe the overall adsorption process.
Analytical and Experimental Study on Noise Attenuation of Multi-Cylinder Diesel Engine with Existing and Modified Muffler
Authors: Ghosh Bankim Bihari , Bhattacharya Paritosh , Bose Prabir Kumar , Vaijanapurkar M.Y.
Published: December 2006

Man's desire for a pollution free atmosphere entails control of air pollution and noise pollution. The principal sources of noise in automotive engines are intake noise, radiator noise, combustion noise, exhaust noise etc. Out of these, exhaust noise is predominant and has to be controlled. Noise pollution affects human beings physiologically and psychologically.

In this paper on reactive muffler for a multi-cylinder diesel engine is designed and modified. More attenuation is given by making some changes in its configuration.

The Bond graph technique has been applied for the analytical results of the muffler. The modelling of acoustic and other systems are easily and logically achieved through Bond graph technique[1,2,3]. Bond graph, invented by Paynter, is a method or representation of a physical system by means of symbols and lines, identifying power flow paths and lumped parameter elements of resistance, capacitance and inductance.

The Bond graph model is created by taking wave propagation in acoustic material into consideration. The analysis of the Bond Graph model was carried out by using software COSMO-KGP. These results were compared with the experimental results and found to be in close agreement.
Acoustic Detection of Buried Landmines Using Pulsed ESPI
Authors: Aranchuk Vyacheslav , Sabatier James M. , Alberts W. C. Kirkpatrick
Published: December 2006

Acoustic methods of landmine detection have demonstrated promising results in detecting buried landmines in laboratory and field tests. They are based on generation of vibrations of the ground and measurement of the vibration response of the ground over the area of interest. A buried landmine can be detected by analyzing spatial distribution of the ground vibration. Reliable detection of mines requires fast measurement of vibration with high spatial resolution. This work studies the application of a pulsed electronic speckle pattern interferometer (ESPI) for the vibration measurement of the ground surface in acoustic landmine detection. Experimental results are presented from laboratory experiments. The effect of the vibration of unconsolidated soil on the speckle decorrelation is discussed. Results show that pulse ESPI can create a spatial map of vibrating ground in a time equal to or shorter than a half a period of vibration and have the ability to detect buried landmines.
Structural Vibrations of Wooden House Walls
Authors: Bolmsvik Åsa
Published: December 2006

The flanking transmission between apartments due to a structure borne source is studied. The apartments studied were two-storey houses with a wooden framework. Acoustic measurements are often made in new built apartments to make sure that they fulfil the building regulations. Traditional measurements give no information about the contribution of the surrounding walls to the sound transmission.

This paper describes a method of measuring flanking transmission. The acceleration levels on the receiving parts in the apartment below the source are studied. Thereby the contribution to the sound pressure in the room from each flanking part can be distinguished.
Laboratory Sound Insulation Measurements of Improved Timber Floor Constructions: A Parametric Survey
Authors: Wuyts D. , Crispin C. , Ingelaere B. , Van Damme M.
Published: December 2006

An extensive measurement survey of timber floor constructions has been carried out by the acoustics laboratory of the Belgian Building Research Institute [1]. The basis of this study was the airborne and structure-borne sound insulation measured on a bare joist floor with OSB (Oriented Strand Board) sub floor. By adding different floor toppings and gypsum board ceilings to the basic floor construction, gradual improvements were recorded. A large number of floors are evaluated in the laboratory and formed a database for parametric studies. Improvements due to cavity absorption, floating floors and suspended ceilings were quantified and ranked by effectiveness. Measurement results revealed remarkable differences between floating floor systems. In addition, sound insulation measurements have been performed on joist floors with concrete toppings. The so-called mixed concrete-timber floors provide a higher mechanical resistance. The effect of the bonding and topping type on the airborne and structure borne sound insulation has been examined in the laboratory. The results of this additional research are briefly compared to traditional floor systems and compared with the (future) Belgian standard values. An overall evaluation of the acoustic relevance of timber floor partitions in and between dwellings is also made.
Impact Sound Insulation Using Timber Platform Floating Floors on a Concrete Floor Base
Authors: Hopkins C. , Hall R.
Published: December 2006

This paper looks at the performance that can be achieved using timber platform floors on concrete floor bases in order to design a platform floor that could provide at least 29dB Δ Lw (both loaded and unloaded) for use in floor constructions described in Approved Document E (2003 Edition). Reconstituted open cell foams were identified as resilient materials that could provide suitable static and dynamic stiffness under lightweight timber floating floors. Using two layers of reconstituted foam a platform floor comprising 22m tongue and grooved chipboard achieved 29dB Δ Lw when loaded, and 30dB Δ Lw unloaded. Indicative tests on double platform floating floors indicated that they may be beneficial in floor designs where negative values of Δ L can not be tolerated due to critical impact sound insulation and structural stability requirements. A double floating floor could use dynamically stiffer resilient materials than would be needed in a single floating floor and still provide the required impact sound insulation and structural stability.
Dynamic Properties of a Sawn Timber Floor Element with High Transverse Bending Stiffness
Authors: Salmela Kirsi , Olsson Anders
Published: December 2006

A novel wooden floor system for blocks of flats, schools and office buildings where long spans are required is investigated. The floor system aims at high stiffness and good vibration performance. In the longitudinal, main load-bearing direction the floor system works as a truss with flanges of longitudinally oriented timber members and web diagonals of transversely oriented members. In the transverse direction the web diagonals work as beams. A 2.4 × 4.8 m floor element with a total height of 260 mm is examined. Laboratory tests as well as static FE calculations show that the bending stiffness in the transverse direction is of the order of one fourth of the bending stiffness in the main direction. The torsional stiffness is however low. The dynamic properties, i.e. natural frequencies and modes of vibration were evaluated using laboratory tests and FE calculations. In general, laboratory tests and FE calculations were in good agreement. As the study shows promising results, further development and testing are proposed. A test floor is planned in which the transversely oriented wooden members will be replaced by thinwebbed beams of wood and hardboard. In future, the floor will be examined with respect to acoustic properties.
Dynamic and Subjective Analysis of a Lightweight/Semi-Heavyweight Floor in a Laboratory
Authors: Ljunggren Fredrik , Ågren Anders
Published: December 2006

A lightweight steel framed floor was tested in a laboratory for eight configurations: continuous/lumped main support, support/unsupported free long sides and concrete/plasterboard as top. The dynamic properties were revealed by modal analysis and subjective evaluations in terms of body perception and perception of vibrating articles. The results showed that the tested parameter that affects the floor most was the top layer. The semi-heavy weight floor with concrete layer was in general judged to be of higher acceptance than the lightweight floor having plaster-boards on the top. Additionally, the lightweight floor was used in a series of experiments where the effect of modified support and the effect of adding line loads of various degree of mechanical connection were tested. This part aims to simulate how the dynamics of a floor stepwise might change going from a bare floor to a floor installed inside a real building. The results show that the line load, mass and stiffness influence the floor in terms of changed natural frequencies. Depending on where on the floor the loads are located, different modes were affected and, depending on how the loads were connected to the floor, the gained stiffness varied slightly.
Reflections on Truth, Tradition, and the Psychoanalytic Tradition of Truth
Authors: Segal Hanna
Published: January 2007

This paper describes psychoanalysis as a theory and practice aimed at the attainment of truth. In this sense, it resembles other fields of science, and its traditions are paradigms that have been formed through the accumulation of clinical evidence, and which in turn shape what we can see. But psychoanalysis is specifically concerned with the truth of psychic reality and with change that occurs through coming to know this truth and withstand it, and thus tradition in psychoanalysis also refers to the boundaries of the field defined by this concern. By tracing some of the developments of psychoanalytic thinking from Freud through Klein and Bion, the paper stresses how these analysts have introduced significant changes in psychoanalysis both in terms of content and method, while still adhering to its essential tradition of a search for truth.
Ruth B. Purtilo and Henk A.M.J. ten Have (Eds.). Ethical Foundations of Palliative Care for Alzheimer Disease. Baltimore, MD: Johns Hopkins University Press, 2004.
Authors: Gordon Michael
Published: January 2007

Résultant de la contribution d'une vingtaine d'auteurs oeuvrant dans les champs de l'éthique, des soins palliatifs et des sciences neuro-comportementales, cet ouvrage propose une vaste exploration des relations entre éthique, soins palliatifs et démences incluant celle de type Alzheimer. Une variété de questions de pointe y sont abordées, le développement menant souvent à un questionnement des fondements de l'approche actuelle en matière de soins palliatifs.
If You can't Beat Them, Join Them: Government Cleansings of Witches and Mau Mau in 1950s Kenya
Authors: Luongo Katherine
Published: January 2007

During the mid-1950s British administrators in the Machakos District of Kenya enlisted categories of Kamba occult “experts”—“witchdoctors” and “cleansers”—to cleanse local “witches” and migrants from Nairobi who were believed to have taken the Mau Mau oath. A compendium of colonial documents concerning the “cleansing” campaigns illustrates how and why the socio-historical context of Mau Mau-era Machakos drove the colonial administration to break with its longstandingde factopolicy of not officially combating supernatural challenges to state authority with supernatural means. The overwhelming disorder wrought by Mau Mau motivated state officials to break with precedent and to identify and employ Kamba “experts” to cleanse Mau Mau adherents and witches.

The widespread and politicized nature of the violence occurring during Mau Mau, and its perceived linkages to the supernatural, precipitated the state's shift to the employment of Kamba experts to combat “witchcraft” and Mau Mau oathing. An anthro-historical approach to understanding Mau Mau in Machakos shows that, while the cleansings constituted a group of “critical moments” at which British colonial officials could argue that they had dealt with supernatural challenges to state authority by rendering them “knowable,” the cleansings also demonstrated the degree to which state authority became situated in Kamba colonial officials and the extent to which the implementation and interpretation of British colonial cleansing policies depended on these local authorities.
The Unique Position of National Human Rights Institutions: A Mixed Blessing?
Authors: Smith Anne
Published: January 2007

National Human Rights Institutions can play a key role in promoting and protecting human rights. They are able to do so by the unique position they occupy between government, civil society, and nongovernmental organizations (NGOs). However, this unique position which holds out opportunities for national human rights institutions also gives rise to problems for such institutions. National human rights institutions have to define and defend their role or space in relation to where they fit in with government and civil society. This can create difficulties for national human rights institutions with respect to their independence and accountability; two key concepts which are crucial for a national human rights institution's legitimacy, credibility, and ultimately its effectiveness. This article explores these challenges and opportunities using examples from different countries. It further draws out a more subtle understanding of independence and accountability by conceptually unearthing the different layers within the two concepts. In conclusion, a number of recommendations are made as to how national human rights institutions can maintain their independence, while engaging with and being accountable to both government and civil society. The article is supported in its conclusions by a series of semi-structured interviews with key institutional players in the national human rights institution world.
The Bounds of the Permissible: Using “Cultural Evidence” in Civil Jury Cases
Authors: Currie Robert J.
Published: January 2007

Au centre de toute considération de la «culture dans le domaine du droit» est la question si, et dans quelle mesure, la culture est justiciable, contestable et peut être introduite comme preuve devant les cours. Des experts des disciplines des sciences sociales et humaines sont souvent appelés à présenter ce genre de preuve. Alors que la Cour suprême du Canada a développé des critères pour évaluer la preuve par expertise, ceux-ci sont plus difficiles à appliquer lorsque la preuve présentée est de nature ‘culturelle’ plutôt que scientifique classique. Le souci de la probité de la preuve par expertise est accru dans les cas où un jury doit évaluer les faits. Ce texte commente une décision récente de la Cour suprême de la Nouvelle-Écosse, en matière de diffamation liée à des propos caractérisant un comportement de raciste, l'utilisant comme plate-forme pour discuter des enjeux particuliers soulevés par la preuve culturelle dans le domaine civil.
The Erasure of Ms. G.: The Cultural Specificity of Substance Abuse and Adjudication Without Imagination
Authors: Roy Vera J.
Published: January 2007

Ce texte promeut l'approche de «l'imagination» tel que définie par Geertz dans le cadre du processus judiciaire, dans le but d'encourager la compréhension et le jugement réfléchi de cas marqués par la différence interculturelle. Cette approche réfléchie – c'est-à-dire, celle qui encourage une conscience du rôle de la culture dominante et de la loi elle-même dans les cas devant la cour – revêt une grande importance dans les cas qui impliquent des personnes d'origine autochtone. L'analyse se fait en trois étapes. Dans un premier temps, un survol de l'historique des relations entre l'État canadien et les peuples autochtones souligne l'aspect culturel de la toxicomanie dans les cas de femmes autochtones. La deuxième étape consiste en une synthèse des statistiques disponibles pour nous donner une meilleure compréhension de l'image de la femme autochtone toxicomane qui prévaut dans le discours social et juridique. Enfin, une analyse du jugement Winnipeg Child and Family Services c. D.F.G. confirme que les idées préconçues jouent un rôle important dans l'appareil judiciaire et démontre les contraintes sur le processus décisionnel créées par le discours libéral de droits individuels. Par conséquent, la disparition de l'identité culturelle, les lacunes dans les arrêts, ainsi que l'incapacité de gérer convenablement les conséquences de ces lacunes, démontrent comment l'absence «d'imagination» peut mettre en péril le fondement même des jugements pour ceux qui sont définis par leur différence devant la société et la loi.
Evaluating the Therapeutic Misconception
Authors: Miller Franklin G , Joffe Steven
Published: January 2007

The "therapeutic misconception," described by Paul Appelbaum and colleagues more than 20 years ago, refers to the tendency of participants in clinical trials to confuse the design and conduct of research with personalized medical care. Although the "therapeutic misconception" has become a term of art in research ethics, little systematic attention has been devoted to the ethical significance of this phenomenon. This article examines critically the way in which Appelbaum and colleagues formulate what is at stake in the therapeutic misconception, paying particular attention to assumptions and implications that clinical trial participation disadvantages research participants as compared with receiving standard medical care. After clarifying the ethical significance of the therapeutic misconception with respect to the decision making of patients, we offer policy recommendations for obtaining informed consent to participation in clinical trials.
Deconstructing Haiku: A Dialogue
Authors: Marshall Ian , Simpson Megan
Published: January 2007

Considering the question of whether haiku can be deconstructed, two readers offer dueling close readings of two classic Japanese haiku and two contemporary American haiku. Though haiku, built out of pure image, seem to avoid making or privileging any definitive claims, they are also made out of the slippery element itself, language, and they test and call into question the very conventions that seem to govern the form. Ultimately, we find common ground in the notion that haiku are provocative and suggestive enough—and self-aware enough about the nature of language—to make the genre itself a kind of deconstructive practice. Even (or especially) in a genre that uses so few words, language repays close attention to the ways in which every utterance communicates more than it, or we, can ever know.
Torture in Abu Ghraib
Authors: Keller Allen S
Published: January 2007

Iraqi detainees subjected to torture and mistreatment at Abu Ghraib prison may continue to suffer from significant physical and psychological consequences of their abuse. This article reports two cases of Iraqi individuals allegedly tortured at Abu Ghraib. Detailed forensic evaluations were conducted approximately one year after their abuse in accordance with international guidelines. The findings of these evaluations substantiate their allegations of torture and confirm the profound health consequences of torture. Furthermore, these cases support assertions that abuse of prisoners was not limited to being perpetrated by guards, but also occurred systematically in the context of interrogations. These cases also raise concerns about inadequate medical care for Iraqi detainees.
A Millisecond Infrared Stopped-Flow Apparatus
Authors: Tang Jia , Gai Feng
Published: December 2006

In this paper, we have described a stopped-flow apparatus that is capable of measuring infrared kinetics in the amide I′ region of a protein's vibrational spectrum. The dead time of this setup, determined by the reducing reaction of 2,6-Dichlorophenolindophenol by l-ascorbic acid, is between 6 to 15 ms, depending on the flow rate. Therefore, this stopped-flow IR method provides a means of measuring infrared kinetics in a time window that is not easily accessible to other mixing-based IR techniques. Using this apparatus, we have studied the alkaline transition of cytrochrome c and have found that this conformational event proceeds in a biphasic manner. The characteristic time constants of these two phases were determined to be 68 ± 20 ms and 624 ± 37 ms, respectively.
Degradation of Curcumin Dye in Aqueous Solution and on Ag Nanoparticles Studied by Ultraviolet—Visible Absorption and Surface-Enhanced Raman Spectroscopy
Authors: Cañamares M. V. , Garcia-Ramos J. V. , Sanchez-Cortes S.
Published: December 2006

The chemical degradation of curcumin (CU) in aqueous solution and on silver nanoparticles was studied by means of ultraviolet (UV)-visible absorption and surface-enhanced Raman (SERS) spectroscopy at different pH levels and upon light irradiation. CU undergoes a chemical degradation in aqueous solution mainly when the pH is increased. The CU degradation is catalytically enhanced in the presence of Ag nanoparticles. In general, CU degradation implies two steps: (1) the breakdown of the interring chain connecting the two CU aromatic side rings, producing smaller phenolic compounds rich in carboxylate groups, and (2) polymerization of the resulting phenolic products, giving rise to phenolic polymeric products. The degradation–polymerization mechanism can be modulated depending on the experimental conditions. The chemical photoproducts resulting from the visible light irradiation are similar to the polycatechol products obtained when catechol is adsorbed on Ag nanoparticles.
Use of Fourier Transform Infrared Spectroscopy to Follow the Heterocumulene Aided Thermal Dehydration of Phthalic and Naphthalic Acids
Authors: Rigout Muriel L. A. , Lewis David M.
Published: December 2006

Fourier transform infrared (FT-IR) spectroscopy has been successfully employed to follow the formation of phthalic anhydride and 1,8-naphthalic anhydride on heating their corresponding acids. The effects of three heterocumulenes, cyanamide, dicyandiamide, and sodium cyanate, on the temperature of formation of the anhydrides were also investigated using this method. It was found that the carbodiimides cyanamide and dicyandiamide dramatically lowered the temperature at which thermal dehydration of the acid led to anhydride formation. It was noted that cyanamide had a stronger catalytic effect than dicyandiamide, presumably due to the electron-withdrawing effect of the amidine group. Sodium cyanate was also found to promote the thermal dehydration of the acids to form the corresponding anhydrides. Under more severe conditions, phthalic acid anhydride formed is seen to react further, leading to the formation of phthalimide. The discrepancy between the products obtained with cyanamide and sodium cyanate leads to the conclusion that, unlike earlier claims, imide formation is not due to the reaction of the anhydride with the urea formed but with sodium cyanate itself. However, only the phthalic anhydride five-membered ring system is sufficiently reactive towards the CNO− nucleophile to form the imide; the six-membered 1,8-naphthalic anhydride system does not react in this way.
Near-Infrared Characterization on the Secondary Structure of Regenerated Bombyx Mori Silk Fibroin
Authors: Mo Chunli , Wu Peiyi , Chen Xin , Shao Zhengzhong
Published: December 2006

Several advantages of the near-infrared (NIR) technique in the characterization of the secondary structure of regenerated Bombyx mori silk fibroin are demonstrated. Silk fibroin films with thicknesses ranging from 50 to 300 μm are suitable for the NIR measurement. The bands due to hydrogen-bonded water are independent in the NIR spectra and facilitate our investigation of the amide region. Analysis of the combination modes of amide groups in the NIR spectra could lead to a profile of conformation ratio of silk fibroin, which was supported by nuclear magnetic resonance (NMR) observations.
Chain of Custody for Samples of Live Crude Oil Using Visible—Near-Infrared Spectroscopy
Authors: Betancourt Soraya S. , Bracey Jep , Gustavson Gale , Mathews Syriac G. , Mullins Oliver C.
Published: December 2006

In order to design oil production facilities and strategies, it is necessary to acquire crude oil samples from subsurface formations in oil wells in so-called openhole prior to production. In some environments, such as deepwater production of oil, decisions of huge economic importance are based on such samples. To date, there has been little quality control to verify that the crude oils collected in the sample bottles and analyzed up to a year later in the laboratory have any relation to the actual crude oils in the subsurface reservoirs. These high-pressure samples can undergo myriad deleterious alterations. Here, we introduce the chain-of-custody concept to the oilfield. The visible–near-infrared spectrum of the crude oil is measured in situ in the wellbore at the point of sample acquisition. This spectrum is compared with the spectrum measured on putatively the same fluid in the laboratory at the start of laboratory sample analysis. First, quantitative assessment is made of whether the fluid in the (high-pressure) sample bottle remains representative of formation fluids. Second, any specific changes in the spectrum of the fluid can be related to possible process control failures. Here, the entire process of chain of custody is proven. The chain of custody process can rapidly become routine in the petroleum industry, thereby significantly improving the reliability of any process that depends on fluid property determination.
Water Diffusion and Sorption-Induced Swelling as a Function of Temperature and Ethylene Content in Ethylene-Vinyl Alcohol Copolymers as Determined by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy
Authors: Cava D. , Sammon C. , Lagaron J. M.
Published: December 2006

Attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy has been advantageously used to carry out a simultaneous study of the effect of temperature on sorption, diffusion, swelling rate, and swelling rate factor of ethylene-vinyl alcohol (EVOH) cast films with three different ethylene contents (29, 38, and 44 mol % of ethylene). While the sorption and swelling levels at equilibrium did not appear to be affected by temperature in the temperature range studied, the effect of increasing ethylene content was seen to largely decrease the sorption-induced swelling. It should be noted that all samples showed significant levels of swelling (∼60% in the copolymer with lowest ethylene content), suggesting that films obtained by solution-casting generate polymer morphologies that are far more prone to uptake water than typical melt-extruded ones. It was also observed that increasing the ethylene content led to a reduction of the “effective” D value, while raising the temperature increased diffusion and swelling rate factor. The activation energies obtained for the diffusion of water were relatively low and similar to the typical energy barrier required to break hydrogen bonding interactions, suggesting that water molecules diffuse very easily across the film due to its high chemical affinity with the polymer matrix.
Luminescence Dynamics of Terbium Monodipicolinate in Ethyl Ammonium Nitrate
Authors: Rosen David L.
Published: December 2006

Energy level dynamics are experimentally examined for terbium monodipicolinate dissolved in ethyl ammonium nitrate (EAN). The luminescence lifetime, the luminescence risetime, and the absorption spectrum of terbium monodipicolinate in EAN are measured. The risetime of luminescence in terbium dipicolinate is experimentally shown to be nonzero and measurable. A dynamic model is presented that describes the evolution of terbium dipicolinate luminescence in EAN. The long risetime in the model is caused by a resonance between the 5E6 state in the terbium cation and the lowest triplet state (T1) in the dipicolinate anion. Bacterial endospore components dissolved in EAN are used to check the time resolution of the experimental apparatus. EAN is discussed partly because it is a room-temperature ionic liquid (RTIL), which is a class of solvents that may be useful for detecting bacterial endospores in the atmosphere.
Optimization of Discriminant Partial Least Squares Regression Models for the Detection of Animal By-Product Meals in Compound Feedingstuffs by Near-Infrared Spectroscopy
Authors: Pérez-Marín D. C. , Garrido-Varo A. , Guerrero J. E.
Published: December 2006

This paper evaluates two multivariate strategies for classifying near-infrared (NIR) spectroscopic data for the detection of animal by-product meals (henceforth generically termed AbP) as an ingredient in compound feedingstuffs. Classification models were developed to discriminate between the presence and absence of animal-origin meals in compound feeds using two forms of discriminant partial least squares (PLS) regression: the algorithms PLS1 and PLS2. The training set comprised 433 commercial feeds, of which 148 contained AbP and the other 285 were stated to be AbP-free. Since the initial set contained unequal numbers of each class, the effect of this imbalance was analyzed by applying the same algorithms to a training set containing equal numbers of AbP-free and AbP-containing samples. The best classification model (97.42% of samples correctly classified), obtained with PLS2, that showed less sensitivity to the use of class-unbalanced sets, was externally validated using a set of 18 samples (10 AbP-containing and 8 AbP-free); all samples were correctly classified, except for one AbP-free sample that was classified as containing AbP (false positive). The results suggest that the application of PLS discriminant analysis to NIR spectroscopic data enables detection of AbP, a feed ingredient banned since the bovine spongiform encephalopathy (BSE) crisis; this confirms the value of NIRS qualitative analysis for product authentication purposes.
Infrared Kinetic/Structural Studies of Barrier Reformation in Intact Stratum Corneum following Thermal Perturbation
Authors: Pensack Ryan D. , Michniak Bozena B. , Moore David J. , Mendelsohn Richard
Published: December 2006

Stratum corneum, the outermost layer of the epidermis, constitutes the main barrier to permeability in skin. As such, it has been the target of many approaches for transdermal drug delivery based on methods involving transient modifications of the barrier. An infrared (IR) spectroscopic method has been developed to monitor the kinetics of barrier restoration following an external perturbation. In the current case, temperature perturbation was selected as a convenient means to induce structural changes in the barrier. The method is based on the observation that the ordered lipid phases of the barrier in isolated human stratum corneum exist in part in orthorhombically packed subcells. Such phases display a characteristic splitting of the CH2 rocking vibrations with component frequencies at 720 and 729 cm−1. The latter is reliably diagnostic for orthorhombic phases and is markedly reduced in intensity following a thermal perturbation to 55 °C. The kinetics of barrier recovery following quenching to either 25 °C or 30 °C were monitored by tracking the restoration of the 729 cm−1 band intensity. The kinetics were dominated by exponential growth in the initial stages, followed by linear increases at longer times. The half lives for exponential growth regimes were 52.4 h for the 25 °C quench and 13.8 h for the 30 °C quench. These values are in reasonable accord with those determined with more phenomenological approaches, typically based on restoration of some barrier function. This novel method for monitoring structural reorganization kinetics in intact stratum corneum can readily be extended to evaluate barrier recovery following a variety of treatments used to enhance drug delivery.
Raman Spectra of Biological Samples: A Study of Preprocessing Methods
Authors: Afseth Nils Kristian , Segtnan Vegard Herman , Wold Jens Petter
Published: December 2006

In this study preprocessing of Raman spectra of different biological samples has been studied, and their effect on the ability to extract robust and quantitative information has been evaluated. Four data sets of Raman spectra were chosen in order to cover different aspects of biological Raman spectra, and the samples constituted salmon oils, juice samples, salmon meat, and mixtures of fat, protein, and water. A range of frequently used preprocessing methods, as well as combinations of different methods, was evaluated. Different aspects of regression results obtained from partial least squares regression (PLSR) were used as indicators for comparing the effect of different preprocessing methods. The results, as expected, suggest that baseline correction methods should be performed in advance of normalization methods. By performing total intensity normalization after adequate baseline correction, robust calibration models were obtained for all data sets. Combination methods like standard normal variate (SNV), multiplicative signal correction (MSC), and extended multiplicative signal correction (EMSC) in their basic form were not able to handle the baseline features present in several of the data sets, and these methods thus provide no additional benefits compared to the approach of baseline correction in advance of total intensity normalization. EMSC provides additional possibilities that require further investigation.
Bulk Raman Analysis of Pharmaceutical Tablets
Authors: Matousek P. , Parker A. W.
Published: December 2006

We compare and contrast two Raman collection geometries, backscattering and transmission, to identify their potential for monitoring the bulk chemical composition of turbid media. The experiments performed on pharmaceutical tablets confirm the expected strong bias of the backscattering Raman collection towards surface layers of the probed sample. However, this bias is largely absent with the transmission geometry, exhibiting gross insensitivity to the depth of impurities within the sample. The results are supported by Monte-Carlo simulations. The applicability of transmission geometry to tablets without any thinning is possible because of long migration times of Raman photons in non-absorbing powder media. The absolute measured intensity of the Raman signal was only 12 times lower in transmission geometry compared with backscattering geometry for a standard paracetamol tablet with a thickness of 3.9 mm. This makes detection relatively straightforward, and detectable Raman signals were observed even after propagation through three paracetamol tablets. Given its properties and instrumental simplicity, the transmission method is particularly well suited to the on-line analysis of bulk content of tablets in pharmaceutical applications.
Modification of Kaolinite Surfaces through Mechanochemical Activation with Quartz: A Diffuse Reflectance Infrared Fourier Transform and Chemometrics Study
Authors: Carmody Onuma , Frost Ray L. , Kristóf János , Kokot Serge , Kloprogge J. Theo , Makó Éva
Published: December 2006

Studies of kaolinite surfaces are of industrial importance. One useful method for studying the changes in kaolinite surface properties is to apply chemometric analyses to the kaolinite surface infrared spectra. A comparison is made between the mechanochemical activation of Kiralyhegy kaolinites with significant amounts of natural quartz and the mechanochemical activation of Zettlitz kaolinite with added quartz. Diffuse reflectance infrared Fourier transform (DRIFT) spectra were analyzed using principal component analysis (PCA) and multi-criteria decision making (MCDM) methods, the preference ranking organization method for enrichment evaluations (PROMETHEE) and geometrical analysis for interactive assistance (GAIA). The clear discrimination of the Kiralyhegy spectral objects on the two PC scores plots (400–800 and 800–2030 cm−1) indicated the dominance of quartz. Importantly, no ordering of any spectral objects appeared to be related to grinding time in the PC plots of these spectral regions. Thus, neither the kaolinite nor the quartz are systematically responsive to grinding time according to the spectral criteria investigated. The third spectral region (2600–3800 cm−1, OH vibrations), showed apparent systematic ordering of the Kiralyhegy and, to a lesser extent, Zettlitz spectral objects with grinding time. This was attributed to the effect of the natural quartz on the delamination of kaolinite and the accompanying phenomena (i.e., formation of kaolinite spheres and water). The mechanochemical activation of kaolinite and quartz, through dry grinding, results in changes to the surface structure. Different grinding times were adopted to study the rate of destruction of the kaolinite and quartz structures. This relationship (i.e., grinding time) was classified using PROMETHEE and GAIA methodology.
Tuning D* with Modified Thermal Detectors
Authors: Simcock M. N. , Myrick M. L.
Published: December 2006

We report on the fabrication and characterization of a modified thermopile detector that has a spectral detectivity, D*, primarily determined by the absorbance of a polymer film. This was done by coating the detector with a metal mirror, followed by the polymer film, so that the film absorbances are responsible for most thermal conversion. The detector is designed to tailor the spectral response of optical systems more specifically to analytes in order to improve precision in methods such as multivariate optical computing and simple photometry. Interference effects in the thin-film response are eliminated by the textured surface of the silicon thermopile, which makes the spectral response relatively simple. The maximum detectivity due to a 1-micrometer-thick film is found to be 20% of the detectivity of the original wide-band detector at 10 Hz modulation frequency. We estimate the thermal diffusion length in the polymer at 10 Hz to be 40 micrometers. We also suggest that the detectivity of the modified detector can be approximated as the product of the D* of the underlying thermal detector and the absorbance of the modifying film, provided the modulation frequency is low and interference effects are defeated.
Orientation-Independent Spectra for Biaxial Systems in Polarized Raman Microspectrometry
Authors: Sourisseau Claude , Talaga David
Published: December 2006

From an extension of the scattering intensity expressions in polarized Raman macrospectrometry to the case of micro-Raman backscattering experiments, we have established theoretical expressions to calculate orientation-independent intensity sums. This approach makes use of the K2 Raman invariant and of correction coefficients due to integration of the Raman scattering over the cone of collection of the objective lens, and it may be applied to uniaxial as well as to biaxial symmetry systems. The intensity sums thus obtained are expected to be orientation insensitive and allow one to compare conformational changes in various biaxially oriented polymer samples, either amorphous and/or semicrystalline thin films. As application examples we have compared the polarized Raman results obtained for various biaxially oriented amorphous and semicrystalline polystyrene (PS), poly(ethylene terenaphthalate) (PEN), and poly(ethylene terephthalate) (PET) thin film samples with their respective “isotropic spectrum” and have considered the different main conformational changes in related polymer systems. The method is thus tested on these macromolecular systems and appears quite successful in providing evidence for the molecular conformational changes without interferences from spectral contributions due to orientation.
Noninvasive Near-Infrared Blood Glucose Monitoring Using a Calibration Model Built by a Numerical Simulation Method: Trial Application to Patients in an Intensive Care Unit
Authors: Maruo Katsuhiko , Oota Tomohiro , Tsurugi Mitsuhiro , Nakagawa Takehiro , Arimoto Hidenobu , Hayakawa Mineji , Tamura Mamoru , Ozaki Yukihiro , Yamada Yukio
Published: December 2006

We have applied a new methodology for noninvasive continuous blood glucose monitoring, proposed in our previous paper, to patients in ICU (intensive care unit), where strict controls of blood glucose levels are required. The new methodology can build calibration models essentially from numerical simulation, while the conventional methodology requires pre-experiments such as sugar tolerance tests, which are impossible to perform on ICU patients in most cases. The in vivo experiments in this study consisted of two stages, the first stage conducted on healthy subjects as preliminary experiments, and the second stage on ICU patients. The prediction performance of the first stage was obtained as a correlation coefficient (r) of 0.71 and standard error of prediction (SEP) of 28.7 mg/dL. Of the 323 total data, 71.5% were in the A zone, 28.5% were in the B zone, and none were in the C, D, and E zones for the Clarke error-grid analysis. The prediction performance of the second stage was obtained as an r of 0.97 and SEP of 27.2 mg/dL. Of the 304 total data, 80.3% were in the A zone, 19.7% were in the B zone, and none were in the C, D, and E zones. These prediction results suggest that the new methodology has the potential to realize a noninvasive blood glucose monitoring system using near-infrared spectroscopy (NIRS) in ICUs. Although the total performance of the present monitoring system has not yet reached a satisfactory level as a stand-alone system, it can be developed as a complementary system to the conventional one used in ICUs for routine blood glucose management, which checks the blood glucose levels of patients every few hours.
Extended-Range Spectroscopic pH Measurement Using Optimized Mixtures of Dyes
Authors: Raghuraman B. , Gustavson G. , Van Hal R. E. G. , Dressaire E. , Zhdaneev O.
Published: December 2006

The spectroscopic technique for pH measurement is a well-established laboratory technique that can give high-accuracy pH values. Recent studies have shown the advantage of this technique over standard potentiometric methods for pH measurements in fresh water and seawater and also at high temperatures and pressures. However, a limitation of the spectroscopic technique is that a single pH dye is sensitive only over a narrow pH range. We have developed optimized dye mixtures that are both sensitive and accurate over a broad pH range. The measurement is robust and simple, requires a minimum of two wavelengths, and is independent of the volume of the dye mixture added. Optimization of the dye mixture formulation to maximize accuracy in a broad range of pH involves varying both the dye type and its mole fraction and also accounting for spectral noise. This technique has been successfully applied for in situ pH measurements of oilfield formation waters.
Spectrally Resolved Frequency Domain Analysis of Multi-Fluorophore Systems Undergoing Energy Transfer
Authors: Forde Toni S. , Hanley Quentin S.
Published: December 2006

Complex systems of fluorophores undergoing energy transfer can exhibit a variety of anomalous lifetime behavior when probed with frequency domain methods. When presented in traditional apparent lifetime format the data from such systems can exhibit “nodal” behavior in which the computed lifetime approaches ±∞. The location of the nodes is system and frequency dependent. In addition, simpler systems, not undergoing energy transfer, show ill behavior in the region of zero lifetime (τ m) and long lifetime (τφ) due to noise in typical measurements. Here, we systematically investigate systems of multiple fluorophores with and without energy transfer to provide insight into frequency domain investigations of complex systems of fluorophores. The results of simulations are compared to data collected from a multi-fluorophore system designed to exhibit fluorescence resonance energy transfer (FRET) using imaging spectroscopic fluorescence lifetime imaging microscopy (ISFLIM). The results are applicable to both cuvette and imaging arrangements.
Multilayer Enhanced Gold Film over Nanostructure Surface-Enhanced Raman Substrates
Authors: Li Honggang , Baum Caitlin E. , Sun Jian , Cullum Brian M.
Published: December 2006

We have developed a novel class of gold multilayer, surface-enhanced Raman scattering (SERS) substrates that are capable of enhancing SERS signals by 15.3-fold over conventional gold film over nanostructure (GFON) SERS substrates, making them comparable in sensitivity to optimized silver film over nanostructure (SFON) substrates, while providing the long-term stability obtained from gold. They are fabricated by depositing 10 Å thick silver oxide islands on conventional GFON substrates, followed by deposition of a second continuous gold layer. The silver oxide layer acts as a dielectric spacer between the two continuous gold films and produces significantly enhanced SERS signals, as compared to optimized single layer substrates of the same geometry or comparable substrates prepared by deposition of silver islands that are not oxidized. In addition to the enhanced sensitivity of these multilayer substrates, they also exhibit long SERS active shelf-lives (i.e., months), with no measurable degradation in SERS enhancement, and relative standard deviations in SERS enhancement of less than 5.2% across the substrate's surface.