On-chip integrated nanowire device platform with controllable nanogap for manipulation, capturing, and electrical characterization of nanoparticles

Cataloged from PDF version of article.We propose and demonstrate nanowire (NW) device platforms on-chip integrated using electric-field-assisted self-assembly. This platform integrates from nanoprobes to microprobes, and conveniently allows for on-chip manipulation, capturing, and electrical characterization of nanoparticles (NPs). Synthesizing segmented (Au–Ag–Au) NWs and aligning them across predefined microelectrode arrays under ac electric field, we controllably form nanogaps between the self-aligned end (Au) segments by selectively removing the middle (Ag) segments. We precisely control and tune the size of this middle section for nanogap formation in the synthesis process. Using electric field across nanogaps between these nanoprobes, we capture NPs to electrically address and probe them at the nanoscale. This approach holds great promise for the construction of single NP devices with electrical nanoprobe contacts

Determination of water stress with spectral reflectance on sweet corn (Zea mays L.) using classification tree (CT) analysis

Abstract Water stress is one of the most important growth limiting factors in crop production. Several methods have been used to detect and evaluate the effect of water stress on plants. The use of remote sensing is deemed particularly and practically suitable for assessing water stress and implementing appropriate management strategies because it presents unique advantages of repeatability, accuracy, and cost-effectiveness over the ground-based surveys for water stress detection. The objectives of this study were to 1) determine the effect of water stress on sweet corn (Zea mays L.) using spectral indices and chlorophyll readings and 2) evaluate the reflectance spectra using the classification tree (CT) method for distinguishing water stress levels/severity. Spectral measurements and chlorophyll readings were taken on sweet corn exposed to four levels of water stress with 0, 33, 66 and 100 % of pot capacity (PC) before and after each watering time. The results demonstrated that reflectance in the red portion (600-700 nm) of the electromagnetic spectrum decreased and increased in the near infrared (NIR) region (700-900 nm) with the increasing field capacity of water level. Reflectance measured before the irrigation was generally higher than after irrigation in the NIR region and lower in the red region. However, when the four levels of PC and before or after irrigation only were compared, reflectance spectra indicated that water stressed corn plants absorbed less light in the visible and more light in the NIR regions of the spectrum than the less water stressed and unstressed plants. There was a similar trend to reflectance behaviour of water stress levels using chlorophyll readings that decreased over time. The CT analysis revealed that water stress can be assessed and differentiated using chlorophyll readings and reflectance data when transformed into spectral vegetation indices

On-chip integrated nanowire devices with controllable nanogap for manipulation, capturing, and electrical characterization of nanoparticles

Dielectrophoresis (DEP) allows for electric field assisted assembly in spatially non-uniform field distribution, where the induced moment is translated into a net force on polarized particles towards the high field gradient. For example, for a spherical particle of radius r with a permittivity constant ofεp in a host medium with the permittivity ofε m, the dielectrophoretic force is given by (1): where r is the particle radius, ω is the angular frequency and Erms is the root mean square electric field. K is the Clausius-Mossotti function, which depends on the complex permittivity of the spherical particle and the medium [1]. © 2009 IEEE

PREDICTION OF LEAF WATER STATUS USING SPECTRAL INDICES FOR YOUNG OLIVE TREES

WOS: 000326911800012It is important to determine the plant water stress before it can reduce the yield or becomes visible. The aim of this study was to investigate the relationship between remotely sensed hyperspectral reflectance indices and leaf water status (LWS) of olive seedlings (Olea europaea L. cv. 'Ayvalik', 'D9', 'D36', 'Erdek Yaglik', 'Frantoio' and 'Gemlik') at different irrigation regime. A pot experiment was conducted in field conditions with 2-years old olive seedlings for the seasons 2011 and 2012. Four levels of water treatment were applied to the pots to bring about different stress conditions; no stress (I-100), mild stress (I-66), severe stress (I-33) and full stress (I-0). Leaf water potential (LWP) and relative water content (RWC) were determined to assess the LWS of the plants. In addition, canopy spectral reflectance was measured with a handheld spectroradiometer and several spectral vegetation indices were calculated using canopy reflectance data. Analysis showed that the irrigation requirement of Frantoio cultivar was the highest when compared to that of other cultivars, while the lowest amount of water was required by Ayvalik cultivar. According to the stepwise multiple linear regression (SMLR) analysis between spectral indices and LWS of olive seedlings, the coefficient of determination (R-2) of model between RWC and Photochemical Reflectance Index (PRI) was 0.70, while it was 0.81 between LWP and PRI, Soil Adjusted Vegetation Index (SAVI), Normalized Difference Vegetation Index (NDVI) and Normalized Pigment Chlorophyll Index (NPCI). Accordingly, it appeared that LWP could be detected more accurately than RWC using spectral indices. Results of this study indicated that the olive plant was very susceptible to water stress and the remotely sensed spectral data could be used to determine RWC and LWP as an indicator of water stress.General Directorate of Agricultural Research and Policy (GDAR)Gida Tarim Ve Hayvancilik BakanligiThis research was funded by the General Directorate of Agricultural Research and Policy (GDAR)

A study to investigate the relationship between difficult intubation and prediction criterion of difficult intubation in patients with obstructive sleep apnea syndrome

Background and Aim: Obstructive sleep apnea (OSA) syndrome is predisposed to the development of upper airway obstruction during sleep, and it poses considerable problem for anesthetic management. Difficult intubation (DI) is an important problem for management of anesthesia. In this clinical research, we aim to investigate the relationship between DI and prediction criteria of DI in cases with OSA. Materials and Methods: We studied 40 [OSA (Group O, n = 20) and non-OSA, (Group C, n = 20)] ASA I-II, adult patients scheduled tonsillectomy under general anesthesia. Same anesthetic protocol was used in two groups. Intubation difficulties were assessed by Mallampati grading, Wilson sum score, Laryngoscopic grading (Cormack and Lehane), a line joining the angle of the mouth and tragus of the ear with the horizontal, sternomental distance, and tyromental distance. Demographic properties, time-dependent hemodynamic variables, doses of reversal agent, anesthesia and operation times, and recovery parameters were recorded. Results: Significant difference was detected between groups in terms of BMI, Mallampati grading, Wilson weight scores, Laryngoscopic grading, sternomental distance, tyromental distance, doses of reversal agent, and recovery parameters. Conclusion: OSA patient′s DI ratio is higher than that of non-OSA patients. BMI Mallampati grading, Wilson weight scores, Laryngoscopic grading, sternomental distance, and tyromental distance evaluation might be predictors for DI in patients with OSA