Physical Measurement Techniques Research Articles

One Light Source — All Colors

AbstractA single source emitting single‐frequency light with tunable color and without the need of changing toxic chemicals, as it is the case for dye lasers, is desired by many scientists. The Department of Microsystems Engineering IMTEK at the University of Freiburg together with the Fraunhofer Institute for Physical Measurement Techniques IPM now extend the tuning range of continuous‐wave optical parametric oscillators into the visible spectrum by integrated, intra‐cavity frequency doubling. Combination of these two nonlinear‐optical effects enables the operator to deliberately choose any wavelength between 430 and 690 nm.

Tophus Measurement as an Outcome Measure for Clinical Trials of Chronic Gout: Progress and Research Priorities

Despite the recognition that tophus regression is an important outcome measure in clinical trials of chronic gout, there is no agreed upon method of tophus measurement. A number of methods have been used in clinical trials of chronic gout, from simple physical measurement techniques to more complex advanced imaging methods. This article summarizes methods of tophus measurement and discusses their properties. Physical measurement using Vernier calipers meets most aspects of the Outcome Measures in Rheumatology (OMERACT) filter. Rigorous testing of the complex methods, particularly with respect to reliability and sensitivity to change, is needed to determine the appropriate use of these methods. Further information is also required regarding which method of physical measurement is best for use in future clinical trials. The need to develop and test a patient-reported outcome measure of tophus burden is also highlighted.

Methods of tophus assessment in clinical trials of chronic gout: a systematic literature review and pictorial reference guide

ObjectiveTo identify methods of tophus measurement for gout studies, summarise the properties of these methods and compile a detailed pictorial reference guide to demonstrate the methods.MethodsA systematic search strategy for...

Mesomorphic properties of biphenyl derivatives with cholesteryl moiety

A series of cholesteryl 4’-alkyloxybiphenyl-4-carboxylates (CnH2n+1OC6H4 C6H4COOCh, where Ch = cholesteryl) possessing different length of alkyl chain (n = 6, 8, 10, 12, 14, 16, 18) were synthesized and their molecular structures were proposed via physical measurement and spectroscopic techniques. Phase transition temperatures and thermal parameters were obtained from differential scanning calorimetry. Observation under polarizing optical microscope revealed all the members of the series exhibiting fan-shaped texture which can be assigned to the SmA phase. Additional mesophase was observed for lower members whereby C6-14 derivatives displayed fan-shaped and oily streaks textures of cholesteric phase. The influence of structural changes (core structure and terminal chain) on the mesomorphic properties is discussed. Key words: Cholesteryl ether, biphenyl, cholesteric, smectic A.

Synthesis and smectogenic A and C* properties of (S)-(-)-2-Methylbutyl 4'-(4"-n-alkanoyloxybenzoyloxy) biphenyl-4-carboxylates

A series of chiral ester (S)-(-)-2-methylbutyl 4’-(4”-n-alkanoyloxybenzoyloxy)biphenyl-4-carboxylates possessing different length of alkyl chain have been isolated and their molecular structures were proposed via physical measurement and spectroscopy techniques. Phase transition temperatures and thermal parameters were obtained from differential scanning calorimetry. Observation under polarizing optical microscope revealed all the members of the series exhibiting fan shaped and helical line textures which can be assigned to the SmA and tilted SmC* phases, respectively. The influence of structural changes (core structure and terminal chain) on the mesomorphic properties is discussed. Key words: Chiral liquid crystals, smectic A, smectic C*, structure-property relationship.

Study of Copper Residue Generated During Cu CMP Process

Copper (Cu) chemical-mechanical polishing (CMP) has been a critical technology for copper damascene manufacturing process for metal interconnects. This paper investigated the mechanism of the copper residue generated during Cu-CMP process. Both electrical testing and various physical measurement techniques have been extensively used for the characterization. For bulk Cu CMP process, the wear surface of the retaining ring caused reduction of the effective down pressure on the wafer, resulting in occurrence of residual copper. For barrier metal CMP process, the protrusion of the copper lines (negative oxide erosion) on the fine pitch line and space array was the main contributor to copper residue on the upper interconnection layer. This paper also examines the effects of slurry selectivity on topography correction and dielectric erosion, in multi-step Cu CMP processes. We proposed an optimal selectivity of Cu/Ta(tantalum)/SiO (0.6/1/0.8) of barrier metal polishing slurry to reduce copper residue between metal patterns and to ensure electrical isolation between neighboring circuit.

Highly Dynamic Measurement of HC Concentrations

The Fraunhofer Institute for Physical Measurement Techniques has developed a system for highly dynamic in-situ gas measurement in motor vehicle catalytic converters at the request of Volkswagen. The objective is to learn how afterburning of fuel residues interferes with optimum operation of catalytic converters.

Établissement du profil de l’activité physique et de l’inactivité : la prochaine générationCet article est tiré d’un supplément intitulé Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines (Favoriser les lignes directrices et la mesure de l’activité physique au Canada: examen scientifique et justification selon les données

The accurate measurement of habitual physical activity is fundamental to the study of the relationship between physical activity and health. However, many physical activity measurement techniques produce variables accurate to only the day level, such as total energy expenditure via self-report questionnaire, pedometer step counts, or accelerometer measurements of minutes of moderate to vigorous physical activity. Monitoring technologies providing more detailed information on physical activity and inactivity behaviour can now be used to explore the relationships between health and movement frequency, intensity, and duration more comprehensively. This paper explores the activity-inactivity profile that can be acquired through objective monitoring, with a focus on accelerometry. Using previously collected objective data, a detailed physical activity profile is presented and case study examples of data utilization and interpretation are provided. The rich detail captured through comprehensive profiling creates new surveillance and study possibilities and could possibly inform new physical activity guidelines. Data are presented in various formats to demonstrate the dangers of misinterpretation when monitoring population adherence to Canada's physical activity guidelines. Recommendations for physical activity-inactivity profiling are provided and future research needs identified.

Physical activity and inactivity profiling: the next generationThis article is part of a supplement entitled Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines co-published by Applied Physiology, Nutrition, and Metabolism and the Canadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab.

The accurate measurement of habitual physical activity is fundamental to the study of the relationship between physical activity and health. However, many physical activity measurement techniques produce variables accurate to only the day level, such as total energy expenditure via self-report questionnaire, pedometer step counts, or accelerometer measurements of minutes of moderate to vigorous physical activity. Monitoring technologies providing more detailed information on physical activity and inactivity behaviour can now be used to explore the relationships between health and movement frequency, intensity, and duration more comprehensively. This paper explores the activity–inactivity profile that can be acquired through objective monitoring, with a focus on accelerometry. Using previously collected objective data, a detailed physical activity profile is presented and case study examples of data utilization and interpretation are provided. The rich detail captured through comprehensive profiling creates new surveillance and study possibilities and could possibly inform new physical activity guidelines. Data are presented in various formats to demonstrate the dangers of misinterpretation when monitoring population adherence to Canada’s physical activity guidelines. Recommendations for physical activity–inactivity profiling are provided and future research needs identified.

Dendritic Spine Viscoelasticity and Soft-Glassy Nature: Balancing Dynamic Remodeling with Structural Stability

Neuronal dendritic spines are a key component of brain circuitry, implicated in many mechanisms for plasticity and long-term stability of synaptic communication. They can undergo rapid actin-based activity-dependent shape fluctuations, an intriguing biophysical property that is believed to alter synaptic transmission. Yet, because of their small size (∼1 μm or less) and metastable behavior, spines are inaccessible to most physical measurement techniques. Here we employ atomic force microscopy elasticity mapping and novel dynamic indentation methods to probe the biomechanics of dendritic spines in living neurons. We find that spines exhibit 1), a wide range of rigidities, correlated with morphological characteristics, axonal association, and glutamatergic stimulation, 2), a uniquely large viscosity, four to five times that of other cell types, consistent with a high density of solubilized proteins, and 3), weak power-law rheology, described by the soft-glassy model for cellular mechanics. Our findings provide a new perspective on spine functionality and identify key mechanical properties that govern the ability of spines to rapidly remodel and regulate internal protein trafficking but also maintain structural stability.

Characteristics of HfO2 thin films grown by plasma atomic layer deposition

The characteristics of HfO2 films grown on Si substrates using a tetrakis-diethyl-amino-hafnium precursor by the remote plasma atomic layer deposition (RPALD) and direct plasma ALD (DPALD) methods were investigated by physical and electrical measurement techniques. The as-deposited HfO2 layer from RPALD exhibits an amorphous structure, while the HfO2 layer from DPALD exhibits a clearly visible polycrystalline structure. Medium energy ion scattering measurement results indicate that the interfacial layer consists of the interfacial SiO2−x and silicate layers. These results suggested that the stoichiometric change in the depth direction could be related to the energetic reactant in a state of plasma used in the plasma ALD process, resulting in damage to the Si surface and interactions between Hf and SiO2−x. The as-deposited HfO2 films using RPALD have the better interfacial layer characteristics than those using DPALD. A metal-oxide-semiconductor capacitor fabricated using the RPALD method exhibits electrical characteristics such as equivalent oxide thickness (EOT) of 1.8 nm with an effective fixed oxide charge density (Qf,eff) of ∼4.2×1011q∕cm2 and that for DPALD has a EOT (2.0 nm), and Qf,eff(∼−1.2×1013q∕cm2).

Langton CM, Njeh CF, (eds): The Physical Measurement of Bone.

Langton CM, Njeh CF, (eds): The Physical Measurement of Bone.

Effects of Pretreatment with a Urea-containing Emollient on Nickel Allergic Skin Reactions

The aim of this study was to evaluate the effect of a moisturizer containing urea on allergic contact dermatitis. Twenty-five nickel-sensitized patients and five controls (non-sensitized volunteers) applied such a moisturizer on the volar side of one forearm twice daily for 20 days, while the other forearm served as the control. After treatment with the moisturizer, patch tests with 0%, 0.5% and 2% NiSO4 in petrolatum were applied in a randomized manner on each arm. After 72 h, the skin reactions were blindly evaluated by clinical scoring and by measuring transepidermal water loss and electrical impedance. After treatment, the baseline transepidermal water loss values were lower and the baseline magnitude impedance index values were higher on the pretreated forearm. According to clinical scoring and measurements with the two physical measurement techniques, the degree of the patch test reactions was equal. All control subjects had negative nickel tests. We concluded that the skin reactivity to nickel in nickel-sensitized patients is not significantly affected by use of the urea-containing moisturizer.

Intraoperative evaluation of limb length in hip arthroplasty using a single AP radiograph.

Previous methods for determining limb length during hip arthroplasty have depended on physical examination and direct measurement techniques. A radiographic technique for assessing limb length intraoperatively with a single anteroposterior (AP) pelvis radiograph was studied in 46 consecutive hip arthroplasties in 41 patients (five with bilateral arthroplasties). Of the 41 patients, 97.6% had either an average postoperative limb length discrepancy of 2.9 mm (-1 mm to +7 mm), or the limb was lengthened no more than 7 mm. This radiographic method has led to one of the most successful results reported in the literature with regard to minimizing significant limb length discrepancy or limb lengthening (maximum of 7 mm) following total hip arthroplasty. The single AP radiograph made intraoperatively with the trial implant in place is a valuable aid in determining limb length in total hip arthroplasty. (Hip International 2005; 15: 199-205).

Intraoperative evaluation of limb length in hip arthroplasty using a single AP radiograph

Previous methods for determining limb length during hip arthroplasty have depended on physical examination and direct measurement techniques. A radiographic technique for assessing limb length intraoperatively with a single anteroposterior (AP) pelvis radiograph was studied in 46 consecutive hip arthroplasties in 41 patients (five with bilateral arthroplasties). Of the 41 patients, 97.6% had either an average postoperative limb length discrepancy of 2.9 mm (-1 mm to +7 mm), or the limb was lengthened no more than 7 mm. This radiographic method has led to one of the most successful results reported in the literature with regard to minimizing significant limb length discrepancy or limb lengthening (maximum of 7 mm) following total hip arthroplasty. The single AP radiograph made intraoperatively with the trial implant in place is a valuable aid in determining limb length in total hip arthroplasty. (Hip International 2005; 15: 199-205).

A review of surface-based microwave and millimeter-wave radiometric remote sensing of the troposphere

Surface-based radiometric sensing of tropospheric parameters has a long history of providing useful measurements of temperature, water vapor, and cloud liquid. In this review, a general overview of physical fundamentals, measurement techniques, and retrieval methodology is given. Several contemporary instruments are then discussed and representative results are presented. Recent and promising developments include multi-frequency radiometers, scanning observations of clouds, and combined active-passive remote sensing. The primary applications of these new technologies are weather forecasting and climate, communications, geodesy and long-baseline interferometry, satellite data validation, air-sea interaction, and fundamental molecular physics.

Comparative evaluation of canal seepage investigation techniques

Various methods are used to estimate the canal seepage rate such as empirical formulae, analytical or analogue studies and the direct seepage measurement techniques, i.e. seepage meters, ponding tests and inflow–outflow tests. Considering significance of physical measurement techniques both ponding and inflow–outflow methods were used to evaluate the seepage losses. These methods have their merits, demerits and limitations which are well understood. However, while interpreting seepage loss evaluations, there can be independent random errors, like the fluctuations in flow conditions affecting different current meter positions, and systematic errors, like the use of different instruments or different methods to measure different terms in the balance. These errors have to be distinguished. The data from various studies in the region have been reviewed and analyzed. A statistical analysis of a number of replications of ponding and inflow–outflow test data of the seepage estimation work on various canals under the Fordwah Eastern Sadiqia (South) project, Bahawalnagar, Pakistan has been done to show the accuracy of results achieved through both the methods. It has been shown that the ponding method is more accurate than the inflow–outflow method as variability of various statistical parameters from the ponding tests is comparatively less. It is proved that inflow–outflow tests should not be used for seepage investigations where seepage rates are fairly small and there is no possibility to use sufficiently long reaches.

Processing effects on the surface properties of α-lactose monohydrate assessed by inverse gas chromatography (IGC)

As mechanically induced processing effects on powdered materials are primarily manifested in small regions on the particle surface, they frequently remain undetected by routine chemical and physical measurement techniques. Inverse gas chromatography was employed in this study to characterize the surface properties of α-lactose monohydrate and determine any changes induced by milling and blending. Results highlighted the potential of this technique to detect and quantify surface energy differences induced by milling and blending and demonstrated how a second unit operation often achieves its effects by means of disrupting flaws caused during the first process. Studies of the flow properties revealed how the bulk behavior of powdered materials can change depending upon processing history, further emphasizing the importance of surface characterization in understanding the behavior of powdered materials.

Clinical Proton Dosimetry Part I: Beam Production, Beam Delivery and Measurement of Absorbed Dose (ICRU Report 59)

International Commission on Radiation Units and Measurements Bethesda, MD: ICRU (1998) 60pp, ISBN: 0-913394-58-0

Magnetically modulated microwave absorption (MMMA) measurements at low magnetic fields on the ferromagnetic state of [TDAE]C60

The ferromagnetic state and reported superconductivity of [TDAE]C60 (where TDAE is titrakis(dimethylamino)ethylene, see Figure) are investigated by magnetically modulated microwave absorption (MMMA). The results are compared with those‐reported using alternative physical measurement techniques, and a hypothesis proposed to explain the observed behavior. No evidence for superconductivity is found.magnified image