Transduction of Single Nanomechanical Pillar Resonators by Scattering of Surface Acoustic Waves.

One of the challenges of nanoelectromechanical systems (NEMS) is the effective transduction of the tiny resonators. Vertical structures, such as nanomechanical pillar resonators, which are exploited in optomechanics, acoustic metamaterials, and nanomechanical sensing, are particularly challenging to transduce. Existing electromechanical transduction methods are ill-suited as they put constraints on the pillars' material and do not enable a transduction of freestanding pillars. Here, we present an electromechanical transduction method for single nanomechanical pillar resonators based on surface acoustic waves (SAWs). We demonstrate the transduction of freestanding nanomechanical platinum-carbon pillars in the first-order bending and compression mode. Since the principle of the transduction method is based on resonant scattering of a SAW by a nanomechanical resonator, our transduction method is independent of the pillar's material and not limited to pillar-shaped geometries. It represents a general method to transduce vertical mechanical resonators with nanoscale lateral dimensions.

An evaluation of the factor structure of the Self-Assessed Wisdom Scale (SAWS) and the creation of the SAWS-15 as a short measure for personal wisdom.

OBJECTIVES: Although wisdom is a desirable life span developmental goal, researchers have often lacked brief and reliable construct measures. We examined whether an abbreviated set of items could be empirically derived from the popular 40-item five-factor Self-Assessed Wisdom Scale (SAWS). DESIGN: Survey data from 709 respondents were randomly split into two and analyzed using confirmatory factor analysis (CFA). SETTING: The survey was conducted online in Australia. PARTICIPANTS: The total sample consisted of 709 participants (Mage = 35.67 years; age range = 15-92 years) of whom 22% were male, and 78% female. MEASUREMENT: The study analyzed the 40-item SAWS. RESULTS: Sample 1 showed the traditional five-factor structure for the 40-item SAWS did not fit the data. Exploratory factor analysis (EFA) on Sample 2 offered an alternative model based on a 15-item, five-factor solution with the latent variables Reminiscence/Reflection, Humor, Emotional Regulation, Experience, and Openness. This model, which replicates the factor structure of the original 40-item SAWS with a short form of 15 items, was then confirmed on Sample 1 using a CFA that produced acceptable fit and measurement invariance across age groups. CONCLUSIONS: We suggest the abbreviated SAWS-15 can be useful as a measure of individual differences in wisdom, and we highlight areas for future research.

The relationship among openness, wisdom, and humor: a preliminary mediation model.

OBJECTIVES: Wisdom researchers acknowledge the complex nature of this ancient construct, although they are yet to agree on its core components. A key question in the literature is whether Openness and Humour are aspects of wisdom or whether Openness is an antecedent of wisdom with Humour as a consequence. METHODS: Using structural equation modelling, we evaluated data from 457 online respondents aged 16-87 years (Mage = 35.19, SD = 17.45). We analyzed a model with Openness as a precursor to Wisdom (conceptualised as a latent mediator variable using parcels of the SAWS Experience, Reminiscence/Reflection, and Emotional Regulation items), with Humor as outcome. We compared this model with a model using Wisdom as a latent mediator variable using parcels of the Three-Dimensional Wisdom Scale-12 (3D-WS-12). RESULTS: A model using Self-Assessed Wisdom Scale (SAWS)-9 latent mediator variable with Openness as precursor to wisdom and Humour as a consequence was good fit for the data and displayed full mediation. Similarly, a model using the 3D-WS-12 as latent mediator variable to measure wisdom and with Openness as a precursor to wisdom and Humour as a consequence also fits the data with full mediation. DISCUSSION: These findings provide empirical support for theoretical suggestions in the literature that Openness is a precursor to wisdom and that Humour is a consequence of wisdom using two of the most common self-report measures of wisdom. An improved understanding of the nature of wisdom and especially of its potential precursors can also be of use in future efforts to facilitate the development of wisdom.

Recent Progress in the Topologies of the Surface Acoustic Wave Sensors and the Corresponding Electronic Processing Circuits.

In this paper, we present an overview of the latest achievements in surface acoustic wave (SAW) sensors for gas or liquid fluid, with a focus on the electrodes' topology and signal processing, as related to the application of the sensing device. Although the progress in this field is mainly due to advances in the materials science and the sensing coatings, the interdigital (IDT) electrodes' organization is also an important tool for setting the acoustic-wave-distribution mode, and, thus, for improvement of the SAW performance. The signal-conditioning system is of practical interest, as the implementation of the SAW, as a compact and mobile system is dependent on this electronic circuit. The precision of the detection of the SAW platform is related not only to the IDT electrodes' geometry but also to their location around the sensing layer. The most commonly used architectures are shown in the present paper. Finally, we identify the needs for the future improvement of these prospective sensors.

Development and validation of a brief self-assessed wisdom scale.

BACKGROUND: This longitudinal study aimed to develop a nine-item Brief Self-Assessed Wisdom Scale (BSAWS) derived from the original 40-item Self-Assessed Wisdom Scale (SAWS). METHODS: The psychometric properties of the shortened scale were evaluated based on a sample of 157 older adults. The factor structure and dimensionality of the original SAWS were examined using confirmatory factor analysis. Subsequent explorative factor analysis of the BSAWS supported the construct validity of the shortened scale. RESULTS: The internal consistency, convergent validity and construct validity of the shortened scale were also evaluated and the results indicated that the BSAWS possesses good psychometric properties and is comparable with the full version. CONCLUSIONS: This scale refinement may help researchers and practitioners conduct epistemological surveys or clinical research related to wisdom.

Quantification of propagating and standing surface acoustic waves by stroboscopic X-ray photoemission electron microscopy.

The quantification of surface acoustic waves (SAWs) in LiNbO3 piezoelectric crystals by stroboscopic X-ray photoemission electron microscopy (XPEEM), with a temporal smearing below 80 ps and a spatial resolution below 100 nm, is reported. The contrast mechanism is the varying piezoelectric surface potential associated with the SAW phase. Thus, kinetic energy spectra of photoemitted secondary electrons measure directly the SAW electrical amplitude and allow for the quantification of the associated strain. The stroboscopic imaging combined with a deliberate detuning allows resolving and quantifying the respective standing and propagating components of SAWs from a superposition of waves. Furthermore, standing-wave components can also be imaged by low-energy electron microscopy (LEEM). Our method opens the door to studies that quantitatively correlate SAWs excitation with a variety of sample electronic, magnetic and chemical properties.

Surface-Acoustic-Wave Sensor Design for Acceleration Measurement.

We suggest a concept design of a SAW-based microaccelerometer with an original triangular-shaped console-type sensing element. Our design is particularly optimized to increase the robustness against positioning errors of the SAW resonators on the opposite sides of the console. We also describe the results of computer simulations and laboratory tests that are in a perfect agreement with each other and present the sensitivity characteristics of a manufactured experimental design device.

Surface Acoustic Wave (SAW)-Enhanced Chemical Functionalization of Gold Films.

Surface chemical and biochemical functionalization is a fundamental process that is widely applied in many fields to add new functions, features, or capabilities to a material's surface. Here, we demonstrate that surface acoustic waves (SAWs) can enhance the chemical functionalization of gold films. This is shown by using an integrated biochip composed by a microfluidic channel coupled to a surface plasmon resonance (SPR) readout system and by monitoring the adhesion of biotin-thiol on the gold SPR areas in different conditions. In the case of SAW-induced streaming, the functionalization efficiency is improved ≈ 5 times with respect to the case without SAWs. The technology here proposed can be easily applied to a wide variety of biological systems (e.g., proteins, nucleic acids) and devices (e.g., sensors, devices for cell cultures).

Occupational injuries in Ohio wood product manufacturing: a descriptive analysis with emphasis on saw-related injuries and associated causes.

BACKGROUND: Stationary sawing machinery is often a basic tool in the wood product manufacturing industry and was the source for over 2,500 injury/illness events that resulted in days away from work in 2010. METHODS: We examined 9 years of workers' compensation claims for the state of Ohio in wood product manufacturing with specific attention to saw-related claims. For the study period, 8,547 claims were evaluated; from this group, 716 saw-related cases were examined. RESULTS: The sawmills and wood preservation sub-sector experienced a 71% reduction in average incidence rate and an 87% reduction in average lost-time incidence rate from 2001 to 2009. The top three injury category descriptions for lost-time incidents within saw-related claims were fracture (35.8%), open wounds (29.6%), and amputation (14.8%). CONCLUSIONS: For saw-related injuries, preventing blade contact remains important but securing the work piece to prevent kickback is also important.

Biological durability of cross laminated timber connections.

Biological durability remains an understudied area of mass timber construction, despite expert warnings on potential moisture and decay issues that may affect building performance. In an effort to bridge the knowledge gap, this article presents experimental data on the performance of fungal-decayed cross laminated timber (CLT) connection assemblies. A total of 560 connection assemblies were made using select CLT species from major global markets. These were mechanically tested following inoculation by two brown rot fungi for a total period of 78 weeks, with the connections periodically harvested after 10, 20, 30, 40, 52, and 78 weeks. The data from the mechanical tests, which included cyclic evaluation using an abbreviated CUREE loading protocol and dowel bearing strength tests performed in accordance with ASTM D5764, are submitted in this repository. The repository also contains information on mass changes to connection assemblies as decay progressed and SAWS model parameters that were calibrated using the raw data generated from the universal testing machine (UTM) during cyclic tests of the connection assemblies. This work is fundamental for accurate assessment of fungal deterioration in mass timber buildings and the data submitted herein could be used by researchers and scientists to model behavior of connections in mass timber buildings, especially in humid and damp regions with high chances of biodeterioration.

Flexible acoustic lens-based surface acoustic wave device for manipulation and directional transport of micro-particles.

Microfluidics is an emerging technology that is playing increasingly important roles in biomedical and pharmaceutical research and development. Surface acoustic waves (SAWs) have been combined with microfluidics technology to establish a SAW-based microfluidics technology that uses the unique interaction between the two techniques to manipulate substances effectively in fluids on the surface of a substrate. This paper reports a method to generate SAWs using conventional planar ultrasonic transducers and acoustic lenses. Additionally, this method is introduced to manipulate particles effectively on a substrate surface. It is demonstrated that the particle positions can be manipulated precisely in any direction on the substrate surface, thus enabling high-precision particle manipulation. We also proposed the generation of nonplanar SAWs via appropriate design of the acoustic lens and realized directional particle transport. In addition, structures to enhance forward-propagating acoustic beams are proposed. The proposed method has potential for use in microfluidics and biomedical applications, allowing tasks such as flexible cell manipulation on a chip to be performed without complex design or micromachining.

Swirl-like Acoustofluidic Stirring Facilitates Microscale Reactions in Sessile Droplets.

Sessile droplets play a crucial role in the microreactors of biochemical samples. Acoustofluidics provide a non-contact and label-free method for manipulating particles, cells, and chemical analytes in droplets. In the present study, we propose a micro-stirring application based on acoustic swirls in sessile droplets. The acoustic swirls are formed inside the droplets by asymmetric coupling of surface acoustic waves (SAWs). With the merits of the slanted design of the interdigital electrode, the excitation position of SAWs is selective by sweeping in wide frequency ranges, allowing for the droplet position to be customized within the aperture region. We verify the reasonable existence of acoustic swirls in sessile droplets by a combination of simulations and experiments. The different periphery of the droplet meeting with SAWs will produce acoustic streaming phenomena with different intensities. The experiments demonstrate that acoustic swirls formed after SAWs encountering droplet boundaries will be more obvious. The acoustic swirls have strong stirring abilities to rapidly dissolve the yeast cell powder granules. Therefore, acoustic swirls are expected to be an effective means for rapid stirring of biomolecules and chemicals, providing a new approach to micro-stirring in biomedicine and chemistry.

Investigation of abrasive saw kickback.

Saw kickback can cause fatal injuries, but only woodcutting saws have regulations and assessment methodologies for kickback. These regulations do not apply to abrasive cutting saws, as their cutting mechanism and dominant kickback mode differ from those of woodcutting saws. This work combines theoretical and experimental tools to investigate abrasive saw kickback. A theoretical model based on frictional engagement during a pinch-based kickback event is shown to predict resultant kickback energy in good agreement with experimental measurements. These measurements were obtained using a specialized machine that generates pinch-based kickback events and measures resultant kickback energy. Upon validating the model, two representative saws, a circular cutoff saw and a chainsaw, were tested using the prototype machine to evaluate their comparative kickback risk. This work demonstrates that pinch-based kickback is a potential safety risk for abrasive cutting saw operators and provides a testing machine design and analytical framework for evaluating this risk.

Pneumonia is a common and early complication of the Severe Alcohol Withdrawal Syndrome (SAWS).

BACKGROUND: Pneumonia (PNA) may complicate the Severe Alcohol Withdrawal Syndrome (SAWS), with ICU admission, mechanical ventilation (MV), prolonged length of stay (LOS), and adverse events. OBJECTIVES: To examine the onset, features and courses of PNA in patients with SAWS to aid management. METHODS: A 33 month contiguous review of SAWS and PNA was conducted at an urban public hospital. RESULTS: There were 279 episodes of Alcohol Withdrawal Syndrome (AWS) among 255 patients. Males predominated (91%) with a mean age of 45.8 years (range 23-73), of whom 31% (87/279) developed SAWS with ICU management. Direct ICU admission occurred for 62 patients; 25 were transferred for delirium, seizures, escalating sedation, PNA or other complications. PNA was identified for 34 ICU direct admissions and 13 ward patients. Ten transfers to the ICU also developed PNA for an ICU total of 44/87 (51%), of whom 82% (36/44) required MV. Another 10 ICU patients without PNA received MV for high dose sedation or respiratory failure. Most ICU patients (72/87 (83%)), including all with MV, required IV infusion of sedation. MV prolonged LOS, but LOS for PNA with MV was similar to all MV. ICU transfers had longer LOS with greater use of MV than direct admits (p<0.05). PNA was identified before ICU admission or transfer for 73% (32/44 (p<0.05)), and usually before intubation. Most PNA was Community Acquired Pneumonia (CAP) with P. Pneumoniae frequently cultured. CONCLUSIONS: PNA with SAWS is predominately CAP and occurs early. Focused ICU admission with respiratory support are priorities of initial management.

Particulate matter emissions during autopsies: a method to reduce exposure.

Particulate matter emitted during autopsies can serve as a vector for numerous viruses or bacteria and can lead to infections. Reducing the exposure of those particles in indoor working environments is, therefore, an important issue. To assess the health risk for employees in forensic medicine, we measure particulate matter in the ambient air during autopsies by using an aerosol spectrometer. The autopsies were performed with either an ordinary oscillating saw or an adapted saw with a suction unit. The particle emissions from both saws were compared to each other in order to evaluate whether a technical adaption leads to a particle reduction. Furthermore, the particle exposure reduction by wearing a face mask and variations in the background concentration in the room were analyzed. High particle concentrations were measured while using the ordinary saw. By using the adapted saw or wearing a face mask, the particle exposure could mostly be avoided. On the majority of the working days, an increase in the background concentration could be observed. Based on this knowledge, the use of a proper suction unit and wearing a face mask during autopsies is necessary. Besides, it is important to have sufficient ventilation in the room so that long-lasting high background concentrations can be prevented.

An assessment of the reliability of cut surface characteristics to distinguish between hand-powered reciprocating saw blades in cases of experimental dismemberment.

Criminal dismemberment is most commonly committed with a variety of hand-powered saws. These saws leave characteristic marks upon the bone that can assist in the identification of the weapon utilized. The current study provides frequencies of presentation of ten cut surface characteristics and examines intra- and interindividual variation between three hand-powered reciprocating saws. Pig radii were used as a proxy for human remains. 42 cut surfaces were created with three hand-powered reciprocating saws by the same researcher. Cut surface characteristics were assessed macroscopically, microscopically and with Scanning Electron Microscope (SEM), as well as photographed with Reflectance Transformation Imaging (RTI). Cut surface polish is the only characteristic that demonstrates consistently significant difference between saws. Five characteristics demonstrate some variation between blades: entrance shaving, breakaway spurs, breakaway notches, pull-out striae, and tooth hop. Four characteristics demonstrate no difference between blades: cut surface striation shape, cut surface striation regularity, harmonics, and exit chipping. Tooth hop is the most reliable characteristic for differentiating between blades in this study, while pull-out striae demonstrates high intra-individual variability and a low frequency of presentation making it unreliable for differentiating between saw blades. Cut surface striations, exit chipping, and breakaway spurs occurred with the highest frequencies and were reliable for determining direction of blade progress and blade stroke, but were not reliable for differentiating between saw blades. Harmonics were absent. Further research is necessary to create large databases of known saw mark examples with known intra- and interindividual variability rates and error rates.

Analysis of Class Characteristics of Reciprocating Saws.

Criminal dismemberment is accomplished using a variety of tools and frequently used to dispose or facilitate the transport of human remains in an attempt to hinder forensic investigation. The present research examined features that may differentiate cuts made in bone by various commercially available reciprocating saw blades. The partial limbs of adult white-tailed deer (Odocoileus virginianus) were used as a proxy for human remains and were cut using five reciprocating saw blades and a hand-powered hacksaw. The resulting false start and complete kerfs were examined macroscopically and microscopically. Kerf characteristics in which significant differences (p ≤ 0.05) between reciprocating blades were noted including minimum kerf width, kerf false start shape, presence of cut surface drift and harmonics, exit chipping size, and striation regularity. Interblade differences generally reflect class characteristics previously established for hand-powered blades. The present research may aid in the identification of reciprocating saw use in forensic contexts.

Characteristics of United States Emergency Department Visits for Traumatic Amputations in the Elderly Adult from 2010 to 2013.

BACKGROUND: Elderly adults (65 years of age and older) are of particular concern for traumatic amputations due to age-related changes in vision and coordination, making them more susceptible to injury. OBJECTIVES: The objective of this study is to describe the epidemiology of traumatic amputations in the elderly adults treated in United States emergency departments (ED). DESIGN: A retrospective analysis using data from the National Electronic Injury Surveillance System from 2010 to 2013. PARTICIPANTS: People aged 65 years and older treated in U.S. hospital EDs for traumatic amputations from 2010 to 2013. RESULTS: There were 15,611 elderly patients treated for amputations from 2010 to 2013, averaging 3,902 amputations per year in the United States. The frequency of amputations declined with increasing age. The mean age was 74 years old. Males represented 84% of the cohort. The majority of the injuries that were recorded took place at home (71%). The most common associated consumer products were saws, lawnmowers, and doors. Saws accounted for approximately 45% of amputations. In females, doors were the most common consumer product associated with amputations. Approximately 45% of amputations were complete amputations. The most common digit to be amputated was the thumb (24%). Approximately 72% of the cases in the cohort were treated and released from the ED. CONCLUSION: Traumatic amputations in elderly adults were frequently due to saws and lawnmowers. An increase in injury prevention efforts in this patient population is warranted.

Quantified effects of chromosome-nuclear envelope attachments on 3D organization of chromosomes.

We use a combined experimental and computational approach to study the effects of chromosome-nuclear envelope (Chr-NE) attachments on the 3D genome organization of Drosophila melanogaster (fruit fly) salivary gland nuclei. We consider 3 distinct models: a Null model - without specific Chr-NE attachments, a 15-attachment model - with 15 previously known Chr-NE attachments, and a 48-attachment model - with 15 original and 33 recently identified Chr-NE attachments. The radial densities of chromosomes in the models are compared to the densities observed in 100 experimental images of optically sectioned salivary gland nuclei forming "z-stacks." Most of the experimental z-stacks support the Chr-NE 48-attachment model suggesting that as many as 48 chromosome loci with appreciable affinity for the NE are necessary to reproduce the experimentally observed distribution of chromosome density in fruit fly nuclei. Next, we investigate if and how the presence and the number of Chr-NE attachments affect several key characteristics of 3D genome organization: chromosome territories and gene-gene contacts. This analysis leads to novel insight about the possible role of Chr-NE attachments in regulating the genome architecture. Specifically, we find that model nuclei with more numerous Chr-NE attachments form more distinct chromosome territories and their chromosomes intertwine less frequently. Intra-chromosome and intra-arm contacts are more common in model nuclei with Chr-NE attachments compared to the Null model (no specific attachments), while inter-chromosome and inter-arm contacts are less common in nuclei with Chr-NE attachments. We demonstrate that Chr-NE attachments increase the specificity of long-range inter-chromosome and inter-arm contacts. The predicted effects of Chr-NE attachments are rationalized by intuitive volume vs. surface accessibility arguments.

Laser-based linear and nonlinear guided elastic waves at surfaces (2D) and wedges (1D).

The characteristic features and applications of linear and nonlinear guided elastic waves propagating along surfaces (2D) and wedges (1D) are discussed. Laser-based excitation, detection, or contact-free analysis of these guided waves with pump-probe methods are reviewed. Determination of material parameters by broadband surface acoustic waves (SAWs) and other applications in nondestructive evaluation (NDE) are considered. The realization of nonlinear SAWs in the form of solitary waves and as shock waves, used for the determination of the fracture strength, is described. The unique properties of dispersion-free wedge waves (WWs) propagating along homogeneous wedges and of dispersive wedge waves observed in the presence of wedge modifications such as tip truncation or coatings are outlined. Theoretical and experimental results on nonlinear wedge waves in isotropic and anisotropic solids are presented.