NANO EXPRESS Open Access Noxious gas detection using carbon nanotubes with Pd nanoparticles Hyang Hee Choi 1 , Junmin Lee 1 , Ki-Young Dong 2 , Byeong-Kwon Ju 2 and Wooyoung Lee 1* Abstract Noxious gas sensors were fabricated using carbon nanotubes [CNTs] with palladium nanoparticles [Pd NPs]. An increase in the resistance was observed under ammonia for both CNTs and CNT-Pd sensors. Under carbon monoxide [CO], the two sensors exhibited different behaviors: for CNT sensors, their resistance decreased slightly with CO exposure, whereas CNT-Pd sensors showed an increase in resistance. The sensing properties and effect of Pd NPs were demonstrated, and CNT-Pd sensors with good repeatability and fast responses over a range of concentrations may be used as a simple and effective noxious gas sensor at room temperature. Introduction Carbon nanotubes [CNTs] have a broad variety of struc- tures that have shown applications as materials for a rapid and innovative change in the field of gas sensing [1]. CNTs have recently been proposed as chemical sensors due to their fast response and high sensitivity toward gas- eous molecules. However, the chemical and physical inter- actions between gas molecules and sensing nanotubes are not yet completely understood [2]. Upon exposure to gas molecules, the electrical conductance of CNTs changes and the threshold voltage is shifted due to charge transfer between the semiconducting CNTs and electron-donating (H 2 S, NH 3 , CO)/electron-withdrawing (NO 2 ) molecules. Theoretical calculations showed the binding energy of CO and NH 3 to carbon nanotubes, which indicates a wea k charge transfer. The c onductivity change may also be caused by contact between the metal electrode and carbon nanotubes and/or the contact between carbon nanotubes [3,4]. CNT-based gas sensors offer significant advantages: unlike oxide-based sensors such as SiO 2 [5]andZnO[6] operated at high temperatures for the detection of noxious gases, CNT-ba sed sensors ha ve various meri ts ranging from a room-temperature operation to a low detection limit. On the other hand, there are several problems to overcome for their practical application. Recen tly, the combination of CNTs with metal nanoparticles [NPs] has attracted much attention [7-10], given the possibility of use in electronics, as catalysts and as biochemical sensors [11-16]. Some researchers have modified CNTs with Pd NPs using chemical vapor deposition [17], sputtering [18], electron-beam evaporation, thermal evaporation [19,20], dielectrophoresis [21,22], or electrodeposition [23,24]. There have been many efforts to detect noxious gases based on CNTs. In the case of the detection of NH 3 , sin- gle-walled carbon nanotube [SWNT]-SnO 2 sensors can detect a low concentration of 10 ppm NH 3 gases at room temperature [25]. In addition, in order to improve the sen- sor’ s response, some works have been explored with increased operation temperature [26,27]. For the detection of CO, a PANI-functionalized CNT sensor showed a reversible response to CO in the range of 100 to 500 ppm [28], and 10 ppm CO detection at 150°C was reported using WO 3 filmswithCNTs[29].Nevertheless,noxious gas sensing at room temperature using CNT-based sen- sors appeared to be difficult. In this study, we synthesized noxious gas sensors based on CNTs with reduced Pd NPs. An improvement of the CNTs’ response was achieved by employing the reduced Pd NPs, which are likely to react with NH 3 and CO and result in more stable and sensitive sensors to these gases. The CNT-Pd sensors were highly sensitive to noxious gases with We Can Help Instructions The B el f as t P oli c e D ep ar t m ent w or ki ng wit h c om m uni t y par t ner s is dev el opi ng a ne w dat ab as e t o s er v e i ndi vi du als wit h Al z hei m er’ s, A uti s m , and ot her c on diti ons t hat c an m ak e t hem pr on e t o w an der : Com pl et e f or m onli ne a nd upl oad ph ot o: htt p: //ww w.c it y of belfa st or g/ index as px ?nid=17 or Com pl et e f or m on r ev er s e si de a nd bri ng or m ail wit h r ec ent p hot o t o: P hot os of t he i ndi vi dual all ow of f ic er s t o m or e eas il y i dent i fy hi m or her i f t hey g et l os t S av es v al ua bl e ti m e w he n mi nut es c ount Al er ts of fi c er s t o pot ent i al tri gg er s an d way s t o c al m t he i ndi vi du al E nabl es f am il y m em ber s or c ar egiv er s t o be n oti fi ed pr o m pt l y w he n t he per s on h as be en f o un d Could Save Lives Belfast Police Department 112 Church Street, Belfast ME Questions / Need help: Call : Chi ef McFadden (207) 338 -5255 “The moments you take to fill out this form today, will assist us in bringing your loved ones back to you.” Chief McFadden Community Partners “As a parent of a teen with autism this program adds greatly to my peace of mind “ Linda Lee Do You Worry About a Loved One Who Wanders? NANO EXPRESS Open Access Highly sensitive hydrogen sensor based on graphite-InP or graphite-GaN Schottky barrier with electrophoretically deposited Pd nanoparticles Karel Zdansky Abstract Depositions on surfaces of semiconductor wafers of InP and GaN were performed from isooctane colloid solutions of palladium (Pd) nanoparticles (NPs) in AOT reverse micelles. Pd NPs in evaporated colloid and in layers deposited electrophoretically were monitored by SEM. Diodes were prepared by making Schottky contacts with colloidal graphite on semiconductor surfaces previously deposited with Pd NPs and ohmic contacts on blank surfaces. Forward and reverse current-voltage characteristics of the diodes showed high rectification ratio and high Schottky barrier heights, giving evidence of very small Fermi level pinning. A large increase of current was observed after exposing diodes to flow of gas blend hydrogen in nitrogen. Current change ratio about 700,000 with 0.1% hydrogen blend was achieved, which is more than two orders-of-magnitude improvement over the best result reported previously. Hydrogen detection limit of the diodes was estimated at 1 ppm H 2 /N 2 . The diodes, besides this extremely high sensitivity, have been temporally stable and of inexpensive production. Relatively more expensive GaN diodes have potential for functionality at high temperatures. Keywords: hydrogen sensor, metal nanoparticles, electrophoresis, Schottky barrier, InP, GaN Introduction Hydrogen gas (H 2 ) monitoring sensors are in demand mainly for detection of H 2 leakage in many industry productions such as, H 2 filling stations, cryogenic cool- ing, research labs, etc. The gas is odorless, colorless, and highly inflammable, and therefore, effective H 2 sensors are of great need for safety reasons. Highly sensitive and selective (i.e., exclusive to one gas) H 2 sensors are needed in forming gas leak detectors for testing leaks in various equipment like vacuum apparatuses, refrigera- tors, heat exchangers or fuel systems in cars, etc. Such detectors contain highly sensitive H 2 sensors and form- ing gas (noncombustive mixture of H 2 in nitrogen) in place of expensive helium (the price of helium has recently risen sharpl y due to increased demand and lim- ited resources) [1]. Thus, research on n ew H 2 sensors has been well sti- mulated. Sensors based on semiconductor Schottky bar- riers principally exceed in sensitivity over the best results reported by sensors based on other sensing prin- ciples. The advantages of these sensors are also long life, low cost, and easy large-scale production. Palladium (Pd)/Si H 2 sensors with two to three orders-of-magni- tude change in current for 150 ppm of H 2 in nitrogen (N 2 ) were published already in 1981 [2]. About twice higher in sensitivity has been achieved with Pd/InP using electrophoretic deposition of Pd [3]. High sensitiv- ity with about six orders-of-magnitude response to 5,000 ppm H 2 in N 2 has been achieved with porous Pd/ GaN Schottky sensors [4]. It has bee n shown on the Pd/ Si Schottky sensor that it responds linearly to H 2 con- centration in the range of three orders-of-magnitude, whiletheresponsestartstosaturateabove1%ofH 2 in N 2 and decreases faster below 10 ppm [5]. Similar beha- vior can be expected at other Schottky barrier sensors as well. Correspondence: zdansky@ufe.cz Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberska 57, 18251 Prague 8, Czech Republic Zdansky Nanoscale Research Letters 2011, 6:490 http://www.nanoscalereslett.com/content/6 The Number of [Old-Time] Basketball Games with Final Score n:n where the Home Team was never losing but also never ahead by more than w Points Arvind Ayyer Department of Physics 136 Frelinghuysen Rd Piscataway, NJ 08854. ayyer@physics.rutgers.edu Doron Zeilberger Department of Mathematics 110 Frelinghuysen Rd Piscataway, NJ 08854. zeilberg@math.rutgers.edu Submitted: Oct 24, 2006; Accepted: Dec 15, 2006; Published: Jan 29, 2007 Mathematics Subject Classification: 05A15 Abstract We show that the generating function (in n) for the number of walks on the square lattice with steps (1, 1), (1, −1), (2, 2) and (2, −2) from (0, 0) to (2n, 0) in the region 0 ≤ y ≤ w satisfies a very special fifth order nonlinear recurrence relation in w that implies both its numerator and denominator satisfy a linear recurrence relation. 1 Introduction We consider walks in the two-dimensional square lattice with steps (1,1), (1,-1), (2,2) and (2,-2). We assign a weight √ z for a unit distance along the x-axis. We constrain them to lie in the region defined by y ≥ 0 and y ≤ w. The motivation for considering such walks is the modelling of polymers forced to lie between plates separated by a small distance. One would then like to calculate various combinatorial quantities. In principle, one hopes to count all possible configurations of the polymer modelling it as a self-avoiding the electronic journal of combinatorics 14 (2007), #R19 1 walk [WSCM, MTW]. Since this is a tough nut to crack, one simplifying approach is to treat the polymer as a directed walk. Studies of this kind have been done in the literature with simpler steps such as Dyck paths ((1, 1) and (1, −1)) which we review in the next section. See, for example, [DR, BORW]. For further developments on the subject, see [R] and the references therein. Even though the motivation came from Physics [BORW], it later occured to us that this is the number of basketball games (post-1896 and pre-1961, when the three-pointer did not exist) in which the home team always leads the visitor by at most w points ending in a tie! 2 ´ Etude - Soccer Games As a warm-up to the study of basketball games, let us consider soccer games with the same condition [BORW]. These are exactly Dyck walks on the square lattice restricted to 0 ≤ y ≤ w starting at the origin and ending on the x-axis. As is usual, we assign a weight √ z for both steps. Let C w (z) be the generating function for such a walk. And D w (z) be the generating function for an irreducible walk. That is, one which does not touch the x-axis in the interior of the walk. A general walk is either the null walk or is composed of an irreducible walk followed by a smaller such walk. Thus, C w = 1 + D w C w . (1) And an irreducible walk starts with the (1, 1) step and ends with the (1, −1) step with an arbitrary walk in between whose width is w − 1. D w = √ zC w−1 √ z = zC w−1 , (2) which implies C w = 1 1 − zC w−1 . (3) This leads to a nice continued fraction expression for C w , which has the distinct aroma of Tchebyshev! Notice that C 0 = 1 and thus, C 1 = 1/(1 − z). Then C w = 1 1− z 1− ··· z 1− w−2 terms z 1 − z for w ≥ 2 (4) (3) is a patently nonlinear recurrence for the generating function. But it does lead to a linear recurrence for the numerator and denominator of C w . This can be seen by setting C w = P w Q w . It is easily seen (do it!) that the linear recurrence relations P w = Q w−1 (5) Q w = Q w−1 − zQ w−2 (6) the electronic journal of combinatorics 14 (2007), #R19 2 with suitable initial conditions gives rise to C w . Notice that these are recurrences with constant coefficients in w but, of course, not in z. This explains the relationship of the denominators with Tchebyshev polynomials of the first kind - T n (z) which satisfies a very similar second order recurrence relation in n with constant coefficients, viz. T n (z) = 2zT n−1 (z) − T n−2 (z). (7) As an aside, note that if w = 2, the number of walks ending at (n, 0) give rise to the Fibonacci numbers PRIMARY RESEARCH Open Access The Factors Influencing Depression Endpoints Research (FINDER) study: final results of Italian patients with depression Rosangela Caruso 1 , Andrea Rossi 2 , Alessandra Barraco 2 , Deborah Quail 3 , Luigi Grassi 1,4* , Italian FINDER study group 1 Abstract Background: Factors Influencing Depression Endpoints Research (FINDER) is a 6-month, prospective, observational study carried out in 12 European countries aimed at investigating health-related quality of life (HRQoL) in outpatients receiving treatment for a first or new depressive episode. The Italian HRQoL data at 6 months is described in this report, and the factors associated with HRQoL changes were determined. Methods: Data were collected at baseline, 3 and 6 months of treatment. HRQoL was measured using components of the 36-item Short Form Health Survey (SF-36; mental component summary (MCS), physical component summary (PCS)) and the European Quality of Life-5 Dimensions (EQ-5D; visual analogue scale (VAS) and health status index (HSI)). The Hospital Anxiety and Depression Scale (HADS) was adopted to evaluate depressive symptoms, while somatic and painful physical symptoms were assessed by using the 28-item Somatic Symptom Inventory (SSI-28) and a VAS. Results: Of the initial 513 patients, 472 completed the 3-month observatio n and 466 the 6-month observation. The SF-36 and EQ-5D mean (± SD) scores showed HRQoL improvements at 3 months and a further smaller improvement at 6 months, with the most positive effect s for SF-36 MCS (baseline 22.0 ± 9.2, 3 months 34.6 ± 10.0; 6 months 39.3 ± 9.5) and EQ-5D HSI (baseline 0.4 ± 0.3; 3 months 0.7 ± 0.3; 6 months 0.7 ± 0.2). Depression and anxiety symptoms (HADS-D mean at baseline 13.3 ± 4.2; HADS-A mean at baseline 12.2 ± 3.9) consistently decreased during the first 3 months (8.7 ± 4.3; 7.5 ± 3.6) and showed a further positive change at 6 months (6.9 ± 4.3; 5.8 ± 3.4). Somatic and painful symptoms (SSI and VAS) significa ntly decreased, with the most positive changes in the SSI-28 somatic item (mean at baseline 2.4 ± 0.7; mean change at 3 months: -0.5; 95% CI -0.6 to -0.5; mean change at 6 months: -0.7; 95% CI -0.8 to -0.7); in ‘interference of over all pain with daily activities’ (mean at baseline 45.2 ± 30.7; mean change at 3 months -17.4; 95% CI -20.0 to -14.8; mean change at 6 months -24.4; 95% CI -27.3 to -21.6) and in ‘having pain while awake’ (mean at baseline 41.1 ± 29.0; mean change at 3 months -13.7; 95% CI -15.9 to -11.5; mean change at 6 month s -20.2; 95% CI -22.8 to -17.5) domains. The results from linear regression analyses showed that the antidepressant switch within classes was consistently associated with a worsening in SF- 36 MCS, EQ-5D VAS and HSI compared to non-switching treatment. Furthermore, between-group antidepressants (AD) switch was associated with a worse SF-36 MCS and EQ-5D HSI. MCS (P = 0.028), PCS (P = 0.036) and HSI (P = 0.002) were inversely related to the number of each previous additional depressive episode. PCS (P = 0.009) and HSI (P = 0.005) were also less improved in patients suffering from a chronic medical condition. Moreover, PCS (P = 0.044) and EQ-5D VAS (P < 0.0001) worsening was consistently associated with the presence of a psychiatric illness in the 24 months before baseline. For every additional point on the SSI-somatic score and on the overall pain VAS score at baseline, HSI score were on average 0.062 (P < 0.001) and 0.001 (P = 0.005) smaller, respectively. * Correspondence: luigi.grassi@unife.it 1 Section of Psychiatry, Department of Medical Sciences of Communicat ion and Behaviour, University of Ferrara, Italy Caruso et al. Annals of General Psychiatry 2010, 9:33 http://www.annals-general-psychiatry.com/content/9/1/33 © 2010 Caruso et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2 .0), which permits unrestricted A PRACTICAL GUIDE TO COMPLYING WITH THE FINAL TANGIBLE PROPERTY REGULATIONS White Paper >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////v 2 A PRACTICAL GUIDE TO COMPLYING WITH THE FINAL TANGIBLE PROPERTY REGULATIONS Introduction On September 19, 2013, the IRS issued the final tangible property repair regulations for Sections 162(a) and 263(a), which modified and superseded the temporary regulations issued on December 23, 2011. These regulations represent some of the most significant tax law changes to affect businesses since the 1986 Internal Revenue Code overhaul. 1 Impacting nearly every business, the regulations provide taxpayers with a broad range of guidance on whether to capitalize or expense amounts paid to acquire, produce, or improve tangible property. Compliance with the regulations is required beginning with the tax year that starts on or after January 1, 2014. To comply, most taxpayers will need to change their processes for accounting for repairs. Revising repair processes is not a trivial task as it requires taking a hard look at your tax and accounting systems and procedures and devising ways to ensure accuracy, enforce policies, reduce manual effort, and document facts and decisions. This white paper can help you plan and prepare for the process and system changes necessary for accurate and efficient compliance with the significant changes found in the tangible property regulations. You’ll learn more about: • Which repair processes are affected by the final regulations • What types of changes need to be made to these processes • How BNA Fixed Assets ™ from Bloomberg BNA can help you comply effectively and efficiently “The final regulations will affect all taxpayers that acquire, produce, or improve tangible property.” –Preamble to the regulations, IRS, September 19, 2013 The Final Regulations Provide Additional Guidance The final tangible property regulations have a long history. Following several court cases involving repair and maintenance expenses for fixed assets, the IRS proposed amendments to the regulations in 2006. The proposed amendments were revised, and re-proposed, several times during a period of seven years, allowing for significant feedback from the public. In 2013, the final regulations were published. Figure 1. History of Tangible Property Regulations Since 2006 1 “New Tangible Property Regulations Impact All Business Owners,” Tanya LaCosse, CPA, Nevada Business, August 8, 2013. Aug. 21, 2006 Proposed Amendments under Section 263(a) Dec. 27, 2011 Withdrew 2008 proposed regulations and issued temporary regulations May 9, 2012 Public Hearing on temporary regulations Sep. 19, 2013 Final regulations published Mar. 10, 2008 Withdrew 2006 amendments and proposed new regulations Jan. 1, 2012 Temporary regulations applied Nov. 20, 2012 Changed applicable date of 2011 temporary regulations to 1/1/14 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////v 3 A PRACTICAL GUIDE TO COMPLYING WITH THE FINAL TANGIBLE PROPERTY REGULATIONS The final regulations provide a general framework for distinguishing capital expenditures from supplies, repairs, maintenance, and other deductible business expenses. They also clarify and expand earlier guidance issued in temporary regulations on acquiring, producing, and improving tangible property, including: • De minimis rule change: The safe harbor ceiling has been eliminated • Routine