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1 26 Rev.Adv.Mater.Sci. 24(2010) O. Maksimov RECENT ADVANCES AND NOVEL APPROACHES OF P-TYPE DOPING OF ZINC OXIDE Oleg Maksimov Materials Research Institute, Pennsylvania State University, University Park, PA Received: January 02, 2010 Abstract. Due to its high radiative stability and superior optoelectronic properties, such as wide direct band gap of ~3.4 ev and high exciton binding energy of ~60 mev, ZnO is considered for the fabrication of ultraviolet and visible light emitting and laser diodes, solar-blind photodetectors. Although proof-of-concept devices were already demonstrated, further progress in this area is slowed down by the difficulties of doping ZnO p-type. Here, we discuss problems associated with doping of ZnO, cover recent progress in this area, and discuss an alternative approach to increase p-type dopability via anion substitution, replacing oxygen with other group VI elements (S, Se, Te). We also propose that these anion-substituted alloys will be extremely promising for fabrication of photovoltaic devices, such as highly efficient thin film solar cells. 1. PROPERTIES AND GROWTH OF ZnO There is significant technological and scientific interest in zinc oxide (ZnO) due to its unique physical and chemical properties [1]. It is radiatively hard wide band gap semiconductor (E G ~3.37 ev) that can be easily doped n-type. Its band gap energy can be tuned by alloying with MgO and CdO from 7.9 ev to 2.3 ev [2], spanning from deep ultraviolet (UV) to visible regions of the spectrum. It has a higher exciton binding energy (E b of ~60 mev) than other wide band gap semiconductors like GaN and SiC, leading to the efficient excitonic transitions at room temperature. In addition, owing to the availability of native substrates 1 and amenability to wet chemical etching, ZnO is an extremely promising material for the development of optoelectronic devices, such as Corresponding author: Oleg Maksimov, light emitting and laser diodes (LEDs and LDs) and solar-blind photo detectors, and transparent thin film transistors. ZnO nanostructures (nanoparticles, nanorods, nanobelts, etc.), which can be synthesized using inexpensive physical vapor transport techniques, were shown to be extremely promising for the application as gas sensors, due to the large surface to volume ratio [3], and microlasers due to the superior optical properties [4]. Furthermore, reports of high-temperature ferromagnetism in ZnO doped with transition metals (known as dilute magnetic oxide semiconductor) [5] coupled with nanosecond-long spin coherence time measured at low temperatures [6] makes this material extremely promising for future application in spin electronics (spintronics). 2 For comparison of ZnO with other wide band gap semiconductors see Table 1. 1 Wafers with the diameter up to 4 inches are available from a number of companies including Cermet Inc., MTI Corporation, and Zn Technology Inc. 2 Use of quantum mechanical spin states associated with the charged particles to propagate information offers potential advantages over the use of charge alone, as in present-day technology. Spintronic devices, combining the advantages of magnetic metals and semiconductors, are expected to be non-volatile, versatile, fast, capable of simultaneous data storage and processing, and power efficient. They can be used in high-density data recording and storage, quantum computation, cryptography, and microelectronic.
2 Recent advances and novel approaches of p-type doping of zinc oxide 27 Table 1. Physical properties of wide band gap semiconductors. Semiconductor Crystal Structure Band gap E G (ev) at ~ 6K E b (mev) ZnO Wurzrite Direct ZnS Zincblende Direct ZnSe Zincblende Direct ZnTe Zincblende Direct GaN Wurzrite Direct H-SiC Wurzrite Indirect Table 2. Best parameters reported for ZnO films. <0002> <10-11> FWHM of band electron density electron mobility peak peak edge emission at room at room at 10K temperature temperature Units degree degree mev cm -3 cm 2 V -1 s -1 Parameter >0.01 > mev 5 x Growth PLD PLD MBE PLD PLD Technique Substrate ScAlMgO 4 ScAlMgO 4 GaN ScAlMgO 4 ScAlMgO 4 Reference [27,81] [27,81] [82] [81] [27] High crystalline quality ZnO films are successfully deposited using a number of growth platforms, including molecular beam epitaxy (MBE), chemical vapor deposition (CVD), pulsed laser deposition (PLD), and reactive sputtering. Elemental sources (Zn and ozone or oxygen plasma), ceramic targets (ZnO), and metalorganic precursors (dimethylzinc and diethylzinc) are used with equal success. The best parameters reported for the ZnO films are shown in Table 2. Some of these growth techniques, such as PLD, can be used to deposit films and device structures only on the small wafers, up to 1 inch in diameter, and are more applicable for academic research. Others, such as sputtering, are easily scalable and allow straightforward integration with modern microelectronic industry. 2. P-TYPE DOPING OF ZnO However, further progress in this area is stalled by the difficulties of doping ZnO p-type. It is generally acknowledged that high enough doping levels are difficult to achieve both due to the background n- type doping originating from the presence of H impurities [7], O vacancies (V O ) [8], and Zn interstitials (Zn i ) [9], and due to the large acceptor activation energies and / or low solubility of commonly used group-v (N, P, As, Sb) and group I (Li) dopants. In addition, a slow transition from p-type to n-type conductivity was observed by a number of groups. It was tentatively assigned either to the acceptor migration from the substitutional to the interstitial position and / or to the hydrogen diffusion [10,11]. In spite of these difficulties, there are reports of ZnO doped p-type with group V (N [12,13] P [14,15], As [16-20], and Sb [21,22]), and group I (Li [23]) elements. Co-doping with two potential acceptors (N and As) [24] or acceptor and donor (N and Al) [25,26] was also studied. In the case of the acceptor-donor co-doping, the improvement is believed to be primarily due to the higher solubility of the forming N-Al-N complex. A temperature modulation epitaxy technique was also applied to achieve N-doped p-type ZnO [27]. Nitrogen-doped layers were grown followed by the deposition of thin undoped layers at quality. In addition, doping with other elements, such as Ag and Bi, was explored [28,29]. These results are summarized in Table 3. Unfortunately, most of these results were extremely challenging to reproduce and nontrivial to interpret. For example, ZnO films grown by PLD on GaAs substrates were reported to be p-type. This was explained by the As diffusion from the GaAs substrate into the ZnO layer [16]. However, addi-
3 28 O. Maksimov Table 3. Summary of attempts to grow p-type doped ZnO films. Dopant Growth N A (cm -3 ) (cm 2 / V s) P (Ohm cm) Reference Technique N CVD 1.06x [12] N CVD ZnO:N remained n-type [13] P Diffusion ZnO:P layer was p-type [14] P Sputtering 1.9x x [15] As PLD [16] As Sputtering 9x [17] As PLD 2.4x x [18] As CVD 1.45x [19] As PLD 4x [20] Sb MBE 1x [21] Sb PLD 1.9x [22] Li PLD 6.04x [23] N + As CVD Mixed conductivity [24] N + Al Sputtering 2.52x [25] N + Al Sputtering 1.45x [26] N PLD 8 [27] Ag PLD 4.9x x [28] Bi MBE ZnO:Bi remained n-type [29] tional effects, such as formation of an interfacial Zn 2 As 2 O 7 layer [30], Ga diffusion into the ZnO film [31,32], and Zn diffusion into the GaAs substrate [33] were reported by other groups. In addition, isolated As atoms should act either as deep acceptors (As is incorporated substitutionally at the O position - As O ) and donors (As is incorporated substitutionally at the Zn position - As Zn ) or remain amphoteric (As is incorporated interstitially - As i ). Thus, p-type conductivity was explained by the formation of a complex with two spontaneous Zn vacancies (As Zn -2V Zn ) [34]. Clearly, data interpretation was not straightforward and the origin of the p-type response remained controversial. Due to the difficulties with achieving highly p-type doped ZnO, proof of concept devices that did not employ p-type ZnO layer, such as n-zno/p-srcu 2 O 2 [35], n-zno/p-sic [36], n-zno/p-si [37], ZnO-based metal-insulator-semiconductor [38], n-gan/zno nanowire/p-gan [39], and n-zno/p-gan were fabricated [40,41]. The last approach was widely explored due to the low lattice mismatch between ZnO and GaN and possibility of band gap engineering using Al x Ga 1-x N alloy. Thus, p-al x Ga 1-x N/ZnO/n- Mg x O LEDs operating at high temperatures, up to 650K, were demonstrated [42]. In addition, there were a few recent reports on the fabrication of homojunction LEDs, indicating continuous progress in this area [43-47]. ZnO-based LEDs produced using spray pyrolysis were particularly promising [48]. Possibility to use such a low-cost and easily scalable technique justifies further development of this material system. Results of these research efforts are summarized in Table 4. In addition, ZnO-based UV photo detectors - another important area of ZnO application - were demonstrated by a number of research groups [49-51]. These devices are promising for the fabrication of the early warning missile defense systems, can be used for high temperature flame detection, for the monitoring of ozone layer, and in solar astronomy. However, homojunction LEDs suffered from high turn-on-voltage, reaching 12 V in the case of Be x O-based LED, and strong deep level defect-related emission. While high turn-on-voltage can be explained by the significant resistivity of the p-type layer, deep level emission may arise due to the inferior crystalline quality of the p-type layer. Although there are reports that a large dopant concentration can be incorporated into ZnO without degradation of a crystalline quality [52,53], a poorer in-plane and out-of-plane aliment, larger tilt and twist, is often observed [54]. This may be due both to the defects
4 Recent advances and novel approaches of p-type doping of zinc oxide 29 Table 4. Characteristics of ZnO-based LEDs. n-layer p-layer (nm) Turn-on voltage (V) Reference ZnO SrCu 2 O [35] ZnO:Al 4H-SiC [36] ZnO Si 385 Under reverse bias [37] ZnO 380, [38] GaN:Si GaN:Mg 382, [39] ZnO:Ga GaN:Mg [40] ZnO:Ga GaN:Mg [41] Mg x O Al y Ga 1-y N [42] ZnO ZnO:N Operate only below 200K [43] Be x O:Ga Be x O:As 363, 388, [44] ZnO ZnO:N 423, [45] ZnO ZnO:As 388, [46] ZnO ZnO:N [47] Mg x O Mg x O:N+In 450, [48] introduced by the dopant, such as acceptor taking interstitial position (P i, As i, Sb i ) pared with the formation of oxygen vacancy (V O ), as well as to the lower growth temperatures used to increase solubility. Therefore, a novel approach is clearly needed to achieve high crystalline quality p-type ZnO layers necessary for the fabrication of low turn-on-voltage LEDs, LDs, and p-n junction photo detectors. 4. GROWTH AND DOPING OF ANION SUBSTITUTIED ZnO It was recently suggested that p-type dopability of ZnO can be improved through the anion substitution, replacing oxygen with other group-vi elements, such as S, Se, and Te. The band alignment between ZnO and zinc chalcogenides (ZnS, ZnSe, ZnTe) is plotted in Fig. 1 [55]. Due to the much higher valence band of zinc chalcogenides, the acceptor activation energy is lower in the anion-substituted alloys (Zn, X = S, Se, Te), making them much more amendable to p-type doping. While the cation substitution is widely used both for the band-gap engineering (Be x O, Mg x O, and Cd x O) [56-58] and for the magnetic doping (Mn x O and Co x O) [59,60], anion substitution is much less studied, with the polycrystalline films being mostly investigated [61,62]. This is particularly surprising since this approach was previously employed to overcome problem of bipolar doping in ZnSe x Te 1-x, where high p-type and n-type levels were reported for Te-rich and Se-rich alloys, respectively [63,64]. A significant success was Fig. 1. Calculated [55] band alignment between ZnO and zinc chalcogenides (ZnX, X = S, Se, and Te). achieved with the so-called d-doped films where p- type dopant (N) was introduced into Te-rich nanoislands embedded within the undoped ZnSe matrix. The net acceptor concentration ([N A - N D ]) ~ 18 cm -3 was achieved in the samples containing less than 3% of Te (ZnSe 0.97 Te 0.03 ) [65]. This is an order of magnitude higher than that achieved by any other technique. There is a report on the epitaxial growth of oxide-rich Zn (y<0.15) using PLD [66]; on the Se-rich side up to 1.35% of oxygen were doped in ZnO y Se 1-y [67,68]. A much larger oxygen content (x<10%) was incorporated into the ZnO x Se 1-x-y
5 30 O. Maksimov Table 5. Summary of attempts to grow anion substituted ZnO alloy. Alloy Composition (%) Growth Crystalline Bowing Reference Technique Quality Parameter(eV) ZnO y S 1-y 0 < y < 100 Sputtering Polycrystalline 3 [61] film Zn S -y 0 < y < 100 Atomic Polycrystalline 3.6 [62] Layer film Deposition Zn S -y 0 < y < 15 PLD Epitaxial film [66] ZnO y Se y 0 < y < 1.35 MBE Epitaxial film [67] ZnO y Se y 0 < y < 1.3 MBE Epitaxial film 8 [68] ZnO x Se 1-x-y 0 < x < 10 MBE Epitaxial film 5 - ZnOS [69] 9 - ZnOSe Zn 0 < y < 5 Chemical Bulk crystal 3 [70] 96 < y < 100 Vapor Transport mev to 5 mev for a heavily nitrogen doped sample [62]. With N becoming a shallow acceptor, high p- type doping levels are much easier to achieve. Fig. 2. Band gap energy plotted vs. lattice constant for selected II-VI semiconductors. Green solid lines and black dotted lines show the estimated band gaps for Me x O and ZnO y X 1-y alloys, respectively. films closely lattice matched to GaP substrates. There, epitaxial stabilization prevented phase separation [69]. In addition, bulk Zn (y<0.05 and y>0.96) crystals were grown using chemical vapor transport technique [70]. All these results, summarized in Table 5, indicated a significant band gap bowing. The valance band of ZnO 0.81 S 0.19 is estimated to be 410 mev higher than that of ZnO. In this case, the acceptor activation energy decreases from ANION SUBSTITUTED ZnO FOR OPTOELECTRONIC AND PHOTOVOLTAIC DEVICES It is important to note that the band gap energy of ZnO 0.81 S 0.19 remains above 3 ev. Thus, an efficient blue emission is expected from the ZnO y S 1-y - based LEDs. In addition, an enhanced photoconductivity was observed in ZnO films co-doped with Te and nitrogen [71]. Therefore, an enhanced performance of the UV photo detectors based on the anion substituted ZnO is also expected. With the cation substitution, band gap of the Me x O (Me = Be, Mg, Cd) can be tuned from the deep UV to the visible range of spectrum. In particular, a 2.6 ev emission line (475 nm) was observed from the Zn 0.84 Cd 0.16 O films, indicating that pure green ZnO/Cd x O LEDs can be fabricated [72]. With the anion substitution, band gap energy of the Me x can be further adjusted throughout the whole visible range (band gap of Zn x Cd 1-x O y Se 1-y can be tuned from 3.4 to 1.7 ev) down to the near-ir region of the spectrum, (band gap of CdO x Te 1-x can decrease to ~1.1 ev assuming bowing parameter of ~3 ev). We plot band gap energies versus lattice parameters for the selected II-VI semiconductors in Fig. 2. Thus, this material is extremely promising for the fabrication of full color and pure white LEDs,
6 Recent advances and novel approaches of p-type doping of zinc oxide 31 Fig. 3. The schematics of a Cd x Te y -based multi-layer graded band gap solar cell consisting of 4 layers with decreasing energy gaps (n + -window layer with E G ~ 3.4 ev, n-absorber layer, i-absorber layer, and a p-type absorber layer with E G ~ 1.5 ev). Fig. 4. The schematics of a system based on a wide band gap Me x O y X 1-y -based solar cell and an upconverter electronically isolated from each other. Up-converter consists of a tandem of two narrow band gap solar cells, such as Ge and GaAs, driving a Me x O y X 1-y -based LED. The sub-band-gap light transmitted by the wide band gap solar cell (h < E G ) is partially up-converted into high-energy photons (h > E G ), which are subsequently absorbed by the wide band gap solar cell. A reflector is located behind the up-converter to maximize collection [79,80]. where red-green-blue emission is obtained from the heterostructures that are grown on the same substrate and differ only in the composition of the quantum well region [73], and photovoltaic devices, in particular, for the design of the multi-layer thin film solar cells [74-76]. In these cells, a wide band gap ZnO:Ga (E G ~3.4 ev) can be used as a transparent top n-type contact, CdTe:N can be employed as a bottom p-type contact (E G ~1.5 ev), and the layers of intermediate composition can be utilized as the absorber layers, as shown in Fig. 3. Due to the compositional gradient, multi-layer solar cells will possess the gradual reduction of the band gap and the variation of electrical conduction type from n + to p + from the front to the back. The number of layers can be increased to any number in order to absorb a major part of the solar spectrum and to produce smooth slopes of energy band edges, improving the photo-generated charge carrier separation and collection. A significant improvement in efficiency is expected for these devices since two major mecha- thermalization of high-energy photons and transmis- dition, since ZnO is already considered as a transparent top contact layer in Cu(In x Ga 1-x )Se 2 -based solar cells [77,78], such a substitution will simplify device fabrication process. Moreover, Me x -based LEDs can be epitaxially integrated with the Me x -based solar cells on the top of narrow-band gap solar cells, such as Ge/GaAs multitandem structures. In this case, two narrow band gap solar cells, absorbing low energy photons, will drive LED emitting high-
7 32 O. Maksimov energy photons. These high-energy photons will be sequentially absorbed by the electrically isolated Me x -based wide band gap solar cell in addition to the photons received directly from sun, as shown in Fig. 4. A significant improvement in the efficiency predicted for such a system [79,80] makes it extremely promising for the space applications where high efficiency is of primary importance. 4. CONCLUSION In conclusion, we reviewed recent progress in the growth of ZnO-based materials and fabrication of ZnO-based devices. We covered difficulties of doping ZnO p-type, which is known as a major obstacle for the fabrication of low turn-on-voltage light emitting and laser diodes and p-n junction photo detectors. We presented and discussed novel and extremely promising approach to achieve highly p-type doped layers via anion substitution, replacing oxygen with other group-vi elements (S, Se, and Te). We also suggested that anion substituted alloys are of particular interest for the use in the photovoltaic devices, such as highly efficient thin film solar cells. REFERENCES [1] U. Ozgur, Y.I. Alivov, C. Liu, A. Teke, M.A. Reschikov, S. Dogan, V. Avrutin, S.J. Cho and H. Morkoc // J. Appl. Phys. 98 (2005) [2] J. Muth and A. Osinsky, In: Wide Bandgap Light Emitting Materials and Devices ed. by G. F. Neumark, I. L. Kuskovsky and H. Jiang (Wiley-VCH, 2007). [3] B.S. Kang, H.T. Wang, L.C. Tien, F. Ren, B.P. Gila, D.P. Norton, C.R. Abernathy, J. Lin and S. J. Pearton // Sensors 6 (2006) 643. [4] A.B. Djurisic and Y.H. Leung // Small 2 (2006) 944. [5] R. Janisch, P. Gopal and N. Spaldin // J. Phys.: Condens. Matter 17 (2005) 657. [6] S. Ghosh, V. Sih, W.H. Lau, D. D. Awschalom, S.Y. Bae, S. Wang, S. Vaidya and G. Chapline // Appl. Phys. Lett. 86 (2007) [7] C.G. Van de Walle // Phys. Rev. Lett. 85 (2000) [8] E.C. Lee, Y.S. Kim, Y.G. Jin and K. J. Chang // Phys. Rev. B 64 (2001) [9] A.F. Kohan, G. Ceder, D. Morgan and C.G. Van de Walle // Phys. Rev. B 61 (2000) [10] L.G. Wanf and A. Zunger // Phys. Rev. Lett. 90 (2003) [11] T.M. Barnes, K. Olson and C.A. Wolden // Appl. Phys. Lett. 86 (2005) [12] X. Li, Y. Yan, T.A. Gessert, C. DeHart, C.L. Perkins, D. Young and T.J. Coutts // Electrochemical and Solid-State Lett. 6 (2003) 56. [13] Z.Q. Fang, B. Claflin, D.C. Look, L.L. Kerr and X. Li // J. Appl. Phys. 102 (2007) [14] S. Jang, J.J. Chen, B.S. Kang, F. Ren, D.P. Norton, S.J. Pearton, J. Lopata and W.S. Hobson // Appl. Phys. Lett. 87 (2005) [15] Z.G. Yu, P. Wu and H. Gong // Appl. Phys. Lett. 88 (2006) [16] Y.R. Ryu, S. Zhu, D.C. Look, J.M. Wrobel, H.M. Jeong and H.W. White // J. Crystal Growth 216 (2000) 330. [17] D.C. Look, G.M. Renlund, R.H. Burgener and J.R. Sizelove // Appl. Phys. Lett. 85 (2004) [18] V. Vaithinathan, B.T. Lee, C.W. Chang, K. Asokan and S.S. Kim // Appl. Phys. Lett. 88 (2006) [19] J.C. Sun, J.Z. Zhao, H.W. Liang, J.M. Bian, L.Z. Hu, H.Q. Zhang, X.P. Liang, W.F. Liu and G.T. Du // Appl. Phys. Lett. 90 (2007) [20] C. Yuen, S.F. Yu, E.S.P. Leong, S.P. Lau, K. Pita, H.Y. Yang and T.P. Chen // J. Appl. Phys. 101 (2007) [21] L.J. Mandalapu, Z. Yang, F.X. Xiu, D.T. Zhao and J.L. Liu // Appl. Phys. Lett. 88 (2006) [22] W. Guo, A. Allenic, Y.B. Chen, X.Q. Pan, Y. Che, Z.D. Hu and B. Liu // Appl. Phys. Lett. 90 (2007) [23] J.G. Lu, Y.Z. Zhang, Z.Z. Ye,Y. J. Zeng, H.P. He, L.P. Zhu, J.Y. Huang, L. Wang, J. Yuan, B.H. Zhao and X.H. Li // Appl. Phys. Lett. 89 (2006) [24] A. Krtschil, A. Dadgar, N. Oleynik, J. Blasing, A. Diez and A. Krost // Appl. Phys. Lett. 87 (2005) [25] G. Lu, Z.Z. Ye, F. Zhuge, Y.J. Zeng, B.H. Zhao and L.P. Zhu // Appl. Phys. Lett. 85 (2004) [26] J.G. Lu, Z.Z. Ye, G.D. Yuan, Y.J. Zeng, F. Zhuge, L.P. Zhu, B.H. Zhao and S.B. Zhang // Appl. Phys. Lett. 89 (2006) [27] A. Tsuzazaki, A. Ohtomo, T. Ohtomo, T. Onuma, M. Ohtani, T. Makino, M. Sumiya, K. Ohtani, S.F. Chichibu, S. Fuke,
8 Recent advances and novel approaches of p-type doping of zinc oxide 33 Y. Segawa, H. Ohno, H. Koinuma and M. Kawasaki // Nature Materials 4 (2005) 42. [28] H.S. Kang, B.D. Ahn, J.H. Kim, G.H. Kim, S.H. Lim, H.W. Chang and S.Y. Lee // Appl. Phys. Lett. 88 (2006) [29] F.X. Xiu, L.J. Mandalapu, Z. Yang, J.L. Li, G. F. Liu and J.A. Yarmoff // Appl. Phys. Lett. 89 (2006) [30] D.J. Rogers, F.H. Teherani, T. Monteiro, M. Soares, A. Neves, M. Carmo, S. Pereira, M.R. Correia, A. Lusson, E. Alves, N.P. Barradas, J.K. Morrod, K.A. Prior, P. Kung, A. Yasan and M. Razeghi // Phys. Stat. Sol. C 3 (2006) [31] M.K. Ryu, S.H. Lee, M.S. Jang, G.N. Panin and T.W. Kang // J. Appl. Phys. 92 (2002) 154. [32] H.F. Liu, S.J. Chua, G.X. Hu, H. Gong and N. Xiang // J. Appl. Phys. 102 (2007) [33] S. Yu. Yuldashev, G.N. Panin, S.W. Choi, V.Sh. Yalishev, L.A. Nosova, M.K. Ryu, S. Lee, M.S. Jang, K.S. Chung and T.W. Kang // Jpn. J. Appl. Phys. 42 (2003) [34] S. Limpijumnong, S.B. Zhang, S.H. Wei and C.H. Park // Phys. Rev. Lett. 92 (2004) [35] H. Ohta, M. Orita, M. Hirano and H. Hosono // J. Appl. Phys. 89 (2001) [36] C. Yuen, S.F. Yu, S.P. Lau, Rusli and T.P. Chen // Appl. Phys. Lett. 86 (2005) [37] P. Chen, X. Ma and D. Yang // J. Appl. Phys. 101 (2007) [38] D.K. Hwang, M.S. Oh, J.H. Lim, Y.S. Choi and S.J. Park // Appl. Phys. Lett. 91 (2007) [39] S.J. Ahn and G.C. Yi // Appl. Phys. Lett. 91 (2007) [40] Y.I. Alivov, J.E. Van Nostrand, D.C. Look, M.V. Chukichev and B.M. Ataev // Appl. Phys. Lett. 83 (2003) [41] D.J. Rogers, F.H. Teherani, A. Yasan, K. Minder, P. Kung and M. Razeghi // Appl. Phys. Lett. 88 (2006) [42] J.W. Osinsky, M.Z. Dong, B. Kauser, A. Hertog, M. Dabiran, P.P. Chow, S.J. Pearton, O. Lopatiuk and L. Chernyak // Appl. Phys. Lett. 85 (2004) [43] S.J. Jiao, Z.Z. Zhang, Y.M. Lu, D.Z. Shen, B. Yao, J.Y. Zhang, B.H. Li, D.X. Zhao, X.W. Fan and Z.K. Tang // Appl. Phys. Lett. 88 (2006) [44] Y. Ryu, T. Lee, J.A. Lubdugan, H.W. White, B.J. Kim, Y.S. Park and C.J. Youn // Appl. Phys. Lett. 88 (2006) [45] Z.Z. Zhang, Z.P. Wei, Y.M. Lu, D.Z. Shen, B.Yao, B.H. Li, D.X. Zhao, J.Y. Zhang, X.W. Fan and Z.K. Tang // J. Crystal Growth 301 (2007) 362. [46] J.C. Sun, J.Z. Zhao, H.W. Liang, J.M. Bian, L.Z. Hu, H.Q. Zhang, X.P. Liang, W.F. Liu and G.T. Du // Appl. Phys. Lett. 90 (2007). [47] A. Tsuzazaki, A. Ohtomo, T. Ohtomo, T. Onuma, M. Ohtani, T. Makino, M. Sumiya, K. Ohtani, S.F. Chichibu, S. Fuke, Y. Segawa, H. Ohno, H. Koinuma and M. Kawasaki // Nature Materials 4 (2005) 42. [48] J. Bian, W. Liu, H. Liang, L. Hu, J. Sun, Y. Luo and G. Du // Chem. Phys. Lett. 430 (2006) 183. [49] W. Yang, R.D. Vispute, S. Choopun, R.P. Sharma, T. Venkatesan and H. Shen // Appl. Phys. Lett. 78 (2001) [50] W. Yang, S.S. Hullavarad, B. Nagaraj, I. Takeuchi, R.P. Sharma, T. Venkatesan, R.D. Vispute and H. Shen // Appl. Phys. Lett. 82 (2003) [51] K.W. Liu, J.Y. Zhang, J.G. Ma, D.Y. Jiang, Y.M. Lu, B. Yao, B.H. Li, D.X. Zhao, Z.Z. Zhang and D.Z. Shen // J. Phys. D 40 (2007) [52] K. Tamura, A. Ohtomo, K. Saikusa, Y. Osaka, T. Makino, Y. Segawa, M. Sumiya, S. Fuke, H. Koinuma and M. Kawasaki // J. Crystal Growth 214 (2000) 59. [53] B.J. Kwon, H.S. Kwack, S.K. Lee, Y.H. Cho, D.K. Hwang and S.J. Park // Appl. Phys. Lett. 91 (2007) [54] W. Guo, A. Allenic, Y.B. Chen, X.Q. Pan, Y. Che, Z.D. Hu and B. Liu // Appl. Phys. Lett. 90 (2007) [55] S.H. Wei and A. Zunger // Appl. Phys. Lett. 72 (1998) [56] Y.R. Ryu, T.S. Lee, J.A. Lubguban, A.B. Corman, H.W. White, J.H. Leem, M.S. Han, Y.S. Park, C.J. Youn and W.J. Kim // Appl. Phys. Lett. 88 (2006) [57] A. Ohtomo, M. Kawasaki, T. Koida, K. Masubuchi, H. Koinuma, Y. Sakurai, Y. Yoshida, T. Yasuda and Y. Segawa // Appl. Phys. Lett. 72 (1998) [58] S.Y. Lee, Y. Li, J.S. Lee, J.K. Lee, M. Nastasi, S.A. Crooker, Q.X. Jia, H.S. Kang and J.S. Kang // Mat. Res. Soc. Symp. Proc. 764 (2003) 413.
9 34 O. Maksimov [59] Z. Jin, M. Murakami, T. Fukumura, Y. Matsumoto, A. Ohtomo, M. Kawasaki and H. Koinuma // J. Crystal Growth 214 (2000) 55. [60] T. Fukumura, Z. Jin, A. Ohtomo, H. Koinuma and M. Kawasaki // Appl. Phys. Lett. 75 (1999) [61] B.K. Meyer, A. Polity, B. Farangis, Y. He, D. Hasselkamp, T. Kramer and C. Wang // Appl. Phys. Lett. 85 (2004) [62] C. Persson, C. Platzer-Bjorkman, J. Malmstrom, T. Torndahl and M. Edoff // Phys. Rev. Lett. 97 (2006) [63] W. Lin, B.X. Yang, S.P. Guo, A. Elmoumni, F. Fernandez and M.C. Tamargo // Appl. Phys. Lett. 75 (2007) [64] M. Strassburg, M. Strassburg, O. Schulz, U. Pohl, A. Hoffmann, D. Bimberg, A. Kontos and Y. Raptis // J. Crystal Growth 248 (2003) 50. [65] I.L. Kuskovsky, Y. Gu, Y. Gong, H.F. Yan, J. Lau, I.C. Noyan, G.F. Neumark, O. Maksimov, X. Zhou, M.C. Tamargo, V. Volkov, Y. Zhu and L. Wang // Phys. Rev. B 73 (2006) [66] Y.Z. Yoo, Z.W. Jin, T. Chikyow, T. Fukumura, M. Kawasaki and H. Koinuma // Appl. Phys. Lett. 81 (2002) [67] W. Shan, W. Walukiewicz, J.W. Ager III, K.M. Yu, J. Wu, E.E. Haller, Y. Nabetani, T. Mukawa, Y. Ito and T. Matsumoto // Appl. Phys. Lett. 83 (2003) 299. [68] Y. Nabetani, T. Mukawa, Y. Ito, T. Kato and T. Matsumoto // Appl. Phys. Lett. 83 (2003) [69] Y. Nabetani, Y. Ito, K. Kamisawa, T. Kato, T. Matsumoto and T. Hirai // Phys. Stat. Sol. C 3 (2006) [70] S. Locmelis, C. Brunig, M. Binnewies, A. Borger, K.D. Becker. T. Homann and T. Bredow // J. Mater. Sci. 42 (2007) [71] H.L. Porter, A.L. Cai, J.F. Muth and J. Narayan // Appl. Phys. Lett. 86 (2005) [72] I.A. Buyanova, J.P. Bergman, G. Pozina, W.M. Chen, S. Rawal, D.P. Norton, S.J. Pearton, A. Osinsky and J.W. Dong // Appl. Phys. Lett. 90 (2007) [73] Y. Luo, S.P. Guo, O. Maksimov, M.C. Tamargo, V. Asnin, F.H. Pollak and Y.C. Chen // Appl. Phys. Lett. 77 (2000) [74] N.B. Chaure, A.P. Samantilleke, R.P. Burton, J. Young and I.M. Dharmadasa // Thin Solid Films 472 (2005) 212. [75] I.M. Dharmasada // Solar Energy Materials & Solar Cells 85 (2005) 293. [76] I.M. Dharmadasa, J.S. Roberts and G. Hill // Solar Energy Materials & Solar Cells 88 (2005) 413. [77] F.J. Haug, M. Krejci, H. Zogg, A.N. Tiwari, M. Kirsch and S. Siebentritt // Thin Solid Films 361 (2000) 239. [78] P.J. Rostan, J. Mattheis, G. Bilger, U. Rau and J.H. Werner // Thin Solid Films 480 (2005) 67. [79] T. Trupke, M.A. Green and P. Wurfel // J. Appl. Phys. 92 (2002) [80] P. Wurfel, Physics of Solar Cells (Wiley- VCH, New York, 2007). [81] A. Ohtomo, K. Tamura, K. Saikusa, K. Takahashi, T. Makino, Y. Segawa, H. Koinuma and M. Kawasaki // Appl. Phys. Lett. 75 (1999) [82] H.J. Ko, Y.F. Chen, T. Yao, K. Miyajima, A. Yamamoto and T. Goto // Appl. Phys. Lett. 77 (2000) 537.
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What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you're getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you'd like help immediately, feel free to search for a similar question, or submit your question or concern.
access denied error while creating fillable pdfAsked by flvetbehavior2006 on September 15, 2015 at 01:37 PM
When I try to make my document into a fillable pdf, it leads me to a webpage which has some code and says, "access denied." How can I make a fillable PDF?
JotForm Support
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subset: commoncrawl


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Bankruptcy Law
Bankruptcy Law Questions? Ask a Bankruptcy Lawyer.
Do student Loans go on Schedule D or F. If D is the unsecure portion the total because their is no property securing this loan.
Response 1: Student loans should be listed on Schedule F because they are unsecured loans.
2. Is a vehicle loan when the property has been repo'd does the remaining portion left owed become a unsecure loan or is it still securred loan.
Response 2: Deficiency amount from a repossessed vehicle becomes an unsecured loan as the lender has taken the collateral for the loan and thus it should be listed on Schedule F.


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Just a quick discussion on who is going to the BETT show, what rumour have you heard and what are you hoping to look at or get an insight into.
6 Replies
Jan 10, 2012 at 4:48 UTC
I am on the Impero Stand (g63) for the whole week so please feel free to come and say hello...
Jan 11, 2012 at 1:53 UTC
Hopefully if i get time and they let me I will do another Spiceworks seminar like last year which was fun and spiceworks even paid for beer :)
Jan 11, 2012 at 6:00 UTC
I avoid shows in London (SpiceWorld is an exception) due to the cost of getting there, and the inconvenience of train or coach travel.
I used to enjoys the shows at NEC, with it's plentiful parking (which used to be free in the early days), and only an hour from home.
Jan 11, 2012 at 6:23 UTC
1st Post
I shall be coming down on friday, hope to see some spiceworks users there!
Jan 12, 2012 at 2:44 UTC
I was down yesterday.
The usual companies, crowds and overpriced food.
But a useful day non the less, a lot of iPad based solutions. Can't think why!
Jan 12, 2012 at 6:52 UTC
I'll be there tommorrow hopefully. Hoping to check out some of those iPad solutions and other fun tech.
This discussion has been inactive for over a year.
You may get a better answer to your question by starting a new discussion.


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What is JotForm?
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At JotForm, we want to make sure that you're getting the online form builder help that you need. Our friendly customer support team is available 24/7.
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Do I lose orders if they go over the limit?Asked by James on November 26, 2014 at 08:31 AM
If I am on the free version and get over 10 orders for my product, ( I think that is the limit. Correct me if I am wrong.), would I lose those orders before I could upgrade to the next pricing level?
I have the same question for monthly submission, whatever they are.
Hi James,
Yes the amount of payment submissions you have on a free account is 10. You can see what is offered with our free plan and our other plans at this link: http://www.jotform.com/pricing
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Home > China Destination > Jiangsu > Zhenjiang > Zhenjiang Food > Soup Dumpling With Crab Cream
Soup Dumpling with Crab Cream
Last updated by chinatravel at 2017/4/29
Zhenjiang Soup Dumpling with Crab Cream is popularly called Crab Dumpling. It is a famous traditional snack of Zhenjiang. It is said to have a history of more than two hundred years. It not only enjoys a great fame along the Shanghai and Nanjing Line, but also wins a great reputation at home and abroad. It has thin skin, excessive soup, plentiful stuffing and delicious taste. If it is eaten together with Zhenjiang aromatic vinegar and ginger shreds, it will not only be tastier, but also can repel cold and relieve greasiness.


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Signs and Symptoms of Tuberculosis in Adults?
Tuberculosis (TB) kills an estimated two million people each year, according to the Mayo Clinic. The active disease affects the lungs and is spread easily from person to person via small water drop...
Read More »
How to Recognize the Signs and Symptoms of Tuberculosis?
Tuberculosis, also known as TB for short, is a disease caused by mycobacteria spread from person to person through the air. TB usually affects a person's lungs (typically the primary site of inocul...
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What is a tuberculosis test?
Tuberculosis (TB) is a condition caused by bacteria that affects the lungs (and sometimes other parts of the body). A skin test is done to help check for the presence of these bacteria.Identificati...
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What is the outcome of tuberculosis?
The bacteria Mycobacterium tuberculosis causes the disease tuberculosis, which affects the lungs of the infected. The bacteria causes pneumonia and inflammation of the lungs which can make breathin...
Read More »
What are the treatments for tuberculosis?
Tuberculosis (TB), a chronic infection caused by mycobacterium tuberculosis bacteria, typically affects the lungs. TB can be spread through close contact. As a treatment precaution, Health Encyclop...
Read More »


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|Episode 803
|Production code
|ITV transmission date
|2nd September 1968 (Monday)
|Stories by
| Harry Driver
Esther Rose
Bruce Norman
|Susan Pleat
|Denis Parkin
|Brian Mills
|Executive Producer
|H.V. Kershaw
|Richard Doubleday
|Previous episode
|28th August 1968
|Next episode
|4th September 1968
Dickie realises he'd be better off serving his apprenticeship. Rag-and-Bone man Tommy Deakin looks for somewhere to keep Dolores, the donkey that pulls his cart. Gregg Flint returns to the area from Germany. He is sorry to hear that the Tanners have split up but tells Elsie that he did warn her. Ray tells Audrey she should enter the "Miss Petrol Pump Beauty Contest". Emily takes care of Dolores so Tommy can go into hospital.
Regular castEdit
- Annie Walker - Doris Speed
- Elsie Tanner - Patricia Phoenix
- Len Fairclough - Peter Adamson
- Effie Spicer - Anne Dyson
- Lucille Hewitt - Jennifer Moss
- Miss Nugent - Eileen Derbyshire
- Dickie Fleming - Nigel Humphreys
- Audrey Fleming - Gillian McCann
- Ray Langton - Neville Buswell
- Maggie Clegg - Irene Sutcliffe
- Gordon Clegg - Bill Kenwright
- Minnie Caldwell - Margot Bryant
Guest castEdit
- TV Times synopsis: Elsie Tanner welcomes an old friend
- Viewing Figures: First UK broadcast - 5,150,000 homes (7th place).
|September 1968 episodes
|Mon 2nd • Wed 4th • Mon 9th • Wed 11th • Mon 16th • Wed 18th • Mon 23rd • Wed 25th • Mon 30th


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Download the latest version of Sony Programmable I O Control Device drivers according to your computer's operating system. All downloads available on this website have been scanned by the latest anti-virus software and are guaranteed to be virus and malware-free.
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Sony Programmable I O Control Device Driver Update UtilitySupported OS: Windows 10, Windows 8.1, Windows 7, Windows Vista, Windows XP
File Version: Version 184.108.40.206
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PCG-Z600NE Driver
Sony ElectronicsSupported OS: All Win 2000
File Version: Version 2.00.00
Release Date: 2000-01-07
File Size: 109.6 KB
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719 DownloadsSubmitted Dec 4, 2003 by Mathew (DG Member):
"This Zip contains the files needed for the Programmable I/O controller for the PCG-Z600NE. Unzip, not the location and then update the driver from the Device Manager. Windows 2000 does not pick up this driver."
pcg-n505x Driver
Sony EricssonSupported OS: Win ME, Win 98SE, Win 98, Win 95
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1,495 DownloadsSubmitted Mar 9, 2005 by Deathr (DG Member):
"Full archive with sound driver, video driver, I/O, and controller - last version by sony electronics"
pcg-f707 Driver
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904 DownloadsSubmitted Feb 21, 2006 by jupi (DG Member):


text:
Simplicity 6888. 1985. Misses halter dress and romper: Top stitched dress and romper have elasticized waistline casing and patch pockets. Bodice wraps at waist and ties at neck.
Links to reviews/blog postsEdit
Add a photo to the gallery by clicking the "modify" button below.
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Discussion in 'NFL Zone' started by sureletsrace, Aug 24, 2013.
I will share in the joy of his misery with you.
Oh, but I thought you couldn't spell Elite without Eli. Lol,screw the giants and overrated eli.
He beat the Cowboys (13-3) in Dallas, Green Bay (13-3) at Lambeau, and New England (16-0) in the Superbowl. It was an incredible run -- especially considering the QBs of those teams - Romo, Favre, and Brady.
One of my favorite things in life is watching Ware sack Eli. Good thing it happens pretty often.
I thought ragging on Eli would have ended after the first superbowl win and MVP, it didnt. Then he did it again and people STILL talk bad about him. Sorry people but if this were Romo we would not give a damn what anyone else said, or what he did for the rest if his career he would be our guy and we would defend him like he was our child. Call Eli what you will but put Super Bowl winner and MVP after it. Luck my behind, you might win one on luck two is skill, sorry, you can get mad, sad, or glad but he was good enough to get through the playoffs to the bowl and flourish. WOW! We were 13-3 and still lost, injured player? Green Bay won with a patchwork line. Lets just let others enjoy their wins so we can enjoy ours, whenever that happens again, and if someone says its luck... I'll tell them I don't care, talk to the hand.
News flash, people already do defend him like he's their child.
Sure hope Eli sucks in week one.
As for the other stuff, I'll pass on that topic tonight.
You can't spell 'belittle' without E-L-I, either.
The hate is supposed to be strong. And we all wish Romo's teams had two Superbowl wins.
You're correct. But when they call Eli elite and he is inconsistent as hell and they slammed our QB, it bothers me. He's not Elite! He went 4 games last year without throwing a TD. How is that Elite?
Eli is the top player on my list of guys I absolutely can't stand. I mean I want to puke every time I see or hear him. But I'm also a realist and try to be fair and objective. He's been The definition of Mt. Clutch most of his career. He has more rings than his brother and Romo combined. He's elite because he has more fourth quarter comebacks than anyone, even the great Tom Brady. Another reason is because there are only ten QB's in the history of football that have lead their team to multiple championship seasons, as much as it pains me to say it, He's one of them. I like Romo more, he's my guy, but as of right now Eli is better and for sure elite. And just for grins, I hate that term Elite!!!
I'd take a lucky win just to get into the playoffs this year.
I don't know why Eli gets so much hate. I mean people call him lucky but you have to have a bit of luck in this game as well. I have nothing but respect for Eli. Only thing I don't like was when he wrote what he wrote when the stadium first opened. Other then that I always thought he was a class act.
Now I can't stand the Niners QB Resskins QB the Eagles QB Chargers QB. As I think they are so overrated and full of themselves.
Eli turns it on when it counts OP, he is the anti-Peyton. Don't worry about him now or in week 1...come December...
unbelieveable. The first SB win was ALL on the D. What about the drop by Assante? The helmet catch was a total fluke; he threw up a prayer and it landed. If you are unable to realize that he has had an INCREDIBLE run of luck then you frankly belong on ignore.
yes you can discount Luck which is why the first SB win NO ONE should give him at all.
yeah, we never got lucky in a Super Bowl
What did Aikman do after he won his third?
Was he as inconsistent as Eli?
there is luck then there is the helmet catch and Assante dropping a pick right in his hands. Sorry you cannot tell the difference


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Here's what you get when you visit Google Reader, the apparently not popular enough RSS reader that Google killed off this week. Google directs readers to a list of alternatives, as do we. I personally hopped over to Feedly, with Digg's reader as a backup.
RELATED: Google Reader's demise -- music video captures crying shame of it


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What can we say? Smaller than the original - except in price.
When Serious Sam exploded onto PCs in April 2001, the games implausible weapons and shameless bloodletting were welcome relief from cerebral first-person shooters such as Half-Life, harking back to a time when space-age blasters were concerned with little more than giving players a monumental body-count. Sadly, though, the developers have since lost sight
of what made the original game so much fun.
Inexplicably, the levels in SSII are much smaller than in the original, the cramped worlds populated by a greatly reduced number of enemies and limiting your opportunities for mass destruction. The actual gunplay also feels less punchy than before, your alien adversaries simply falling apart and disappearing when riddled with gunfire, no matter if youve capped them with a pistol, sawn-off shotgun or rocket launcher.
And, if that wasnt disappointing enough, Serious Sam II is hitting stores at a premium price, Take 2 clearly missing the fact that gamers were willing to forgive the shortcomings of the first game as they could pick it up for a little under 20 quid.


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This Forum has been archived
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Out of plain curiosity why doesnt wikia let burs grant bot status anymore? Thanks, --Kangaroopowah Talk 02:41,9/19/2011
- It can lead to abuse.--GodPray 02:45,9/19/2011
- So why can't they grant the ability if an admin sends a Special:Contact to lets the burs do that? --Kangaroopowah Talk 02:48,9/19/2011
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Ends Friday 7/28
Set of Six Antique Style Black and White Enamel Planter Mugs
These rustic distressed planter mugs are perfect for your succulent collection! They are sure to add rustic charm to your space.
Set of 6
Dimensions: 5 1/2"W x 4"D x 3 1/2"H
Not for drinking use
White and Rose Plaid Wool Throw Blanket
The Inca Stones throw collection is inspired by the Inca stones, perfectly fitted stone blocks in the famous Inca buildings. The pattern looks like a stone mosaic.
This designer throw blanket features a modern plaid style with beautiful tones. Made by Elvang Denmark, a design-oriented high-quality textiles company combining Scandinavian design with one of the world's finest fibers from the Peruvian alpaca. The result is stylish and modern products made with pride and integrity.
From its beginnings, Elvang Denmark has deliberately chosen to maintain its production in Peru, maintaining commitment and engagement with the Peruvians and their tradition and expertise of weaving textiles of alpaca wool.
Material: 50% Alpaca Wool, 40% Sheep Wool & 10% Microfiber
Approximate Weight: 1.25 lbs
Size: 51 x 79 Inches
Dry clean only


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The BioSys PhD Program is offering a PhD scholarship for the project: "What are the determinants of human genetic individuality?"The graduate will have the opportunity to work with world-leading researchers from BioISI (BioSystems and Integrative Sciences Institute) and LaSIGE at the University of Lisbonunder the supervision of Prof. Francisco Couto (LASIGE) and Prof. Margarida Gama-Carvalho (BioISI)
Applications until October 21st (12PM, CET):
How to apply: http://biosys.campus.ciencias.ulisboa.pt/node/6
Objectives: With the conclusion of the human genome project and the advent of next-generation sequencing, research on the human genome advanced towards a deeper understanding of human population diversity, focusing primarily on the identification of common genetic variants. With this project we want to evolve from studying the diversity within a population to the individual. We aim at establishing a measure for genomic similarity (involving both the sequence and structural levels) between an individual genome and a single or group of genomes. Genomics information can spell much more about an individual than thought in the last decades, but the complexity of human behaviour is enormous and the determinants of human genetic individuality may be hard to predict from single genomic properties. This project will follow a systems biology approach to reach for a deeper understanding of the complexity of the human genome by analysing what defines us as individuals. The main goal is to understand how well we can predict if one specific person belongs to a group (for example, defined by a phenotype) by only using genomics data. The results generated by this project will be based on the intensive analysis of human sequencing datasets. By identifying the determinants of human genetic individuality, we will also be able to address some of the current concerns regarding the preservation of individual privacy when addressing the prominent necessity for data sharing [1].[1] Cogo, V. V., Bessani, A., Couto, F. M., & Verissimo, P. (2015, October). A high-throughput method to detect privacy-sensitive human genomic data. In Proceedings of the 14th ACM Workshop on Privacy in the Electronic Society(pp. 101-110). ACM.


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Bank and commodity stocks dragged European benchmarks lower Tuesday as mining stocks pared Monday's gains and the second-quarter earnings season got underway.
Citi selected Frankfurt as the location for the new broker-dealer after also evaluating Paris as an alternative.
New British rules are forcing banks to separate their retail operations from riskier operations.
Barclays Bank PLC announced today that during the Index rebalance that commences following the close of business on Friday, July 14, 2017, there will be no changes to the constituents in the Atlantic Trust Select MLP Index...
On June 30, 2017, ONEOK Partners, L.P.
Regulators and prosecutors have shown that Libor, the global benchmark borrowing rate, is prone to manipulation. Fixing it will probably take years.
The Bank of England has told U.K. lenders to increase their capital buffers to protect themselves against risks ranging from Brexit to an increase in consumer borrowing.
Barclays CEO Ashok Vaswani has spoken to regulators about engaging with the cryptocurrency.
The index will track 450 publicly traded companies with a combined revenue of more than $11 trillion.
It's a classic example of headline risk on a topic Wall Street would prefer to avoid.
Commodity markets, economic growth and the potential for a broad tightening of monetary policy in the developed world over the coming quarters recaptured investors' attention Thursday.
Varley has been an independent director at BlackRock since 2009.
The Serious Fraud Office said the charges include conspiracy to commit fraud and unlawful financial assistance
U.S. stock futures are rising slightly, and European shares are higher after a recovery in the tech sector drives gains in global stocks.
The SFO says the charges include conspiracy to commit fraud and unlawful financial assistance
The U.K.'s Serious Fraud Office said Tuesday that it has charged four former executives of Barclays in a probed linked to the bank's capital raising in 2008.
European benchmarks slumped Thursday after the U.S. Fed's decision to hike rates and begin unloading its balance sheet year, while the BoE's also piled pressure onto London.
Barclays shares extended their decline Thursday on fears Britain's Serious Fraud Office could soon charge the bank and some executives over two controversial crisis-era capital raisings.
Barclays announces the appointment of Chris Leonard as Managing Director, Head of US Rates Trading.
The prankster congratulated Goldman CEO Blankfein on winning an award for a subtweet he sent last week aimed at President Trump.
But CEO Jamie Dimon is "not going to go away."
Barclays Bank PLC announced today the automatic redemption of the iPath ® Short Enhanced MSCI Emerging Markets Index Exchange Traded Note (ticker: EMSA) (the "ETNs").
Bayer is offering 1 billion euros of bonds exchangeable into Covestro shares maturing in 2020.
European stocks were buoyed Thursday by an automotive sector in rude health, recovering commodity prices and the latest developments in Britain's election campaign.
Barclays will sell a larger-than-expected portion of its stake in in Barclays Africa Group, the bank said Thursday, thanks to strong investor demand for shares in the South Africa-based lender.
The U.S. dollar remained pinned to multi-month lows after a set of mixed economic data Wednesday.


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This audiobook comes from the Inventing Your Horse Career Series, an enlightening and entertaining equine audio experience developed by Horse Sense and Cents. In this title, you'll enjoy tips, ideas and stories provided by Bob Jeffreys and Suzanne Sheppard, founders of Two as One Horsemanship.
©2014 Nanette Levin (P)2014 Nanette Levin
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KENDAL Town boss Dave Foster has called on his players to fight for a starting place in his team as the start of the Evo-Stik First Division North draws closer.
With tonight's match against Penrith cancelled, there are now just two games left before Kendal travel to Northwich Victoria seeking the perfect start to their campaign.
And despite only winning one of their five pre-season matches, Foster insists his team will be ready come 3pm on August 16.
"At the end of the day it's all about that first result so you could lose every single pre-season game and win the first match of the season and it's job done," he said.
"I'm pleased with the progress. We are almost there. There have been one or two difficulties with games being called off and having to scuttle around to rearrange fixtures.
"However losing is a habit you don't want to get into. Of course you would like to win every game in pre-season but we've had a decent one without perhaps getting some of the results we should have done."
Workington Town travel to Parkside Road on Saturday and Foster expects a tough challenge from the Cumbrian outfit.
"Everyone is fighting for a starting shirt now," he said.
"We are expecting a bit of a performance. It will be a tough game. I think they will be a little more direct than the teams we have played so far so I expect another step up in intensity now.
"Fitness should be there but it's about trynig to get match fit.
"The players are beginning to understand their roles and will hopefully be making a statement that they should be wearing that shirt in a few weeks time."
The Mintcakes travelled to Bootle on Saturday and found themselves on the wrong-end of a seven-goal thriller.
The Liverpool-based outfit took the lead but were pegged back by free-scoring Mark Jackson as the teams returned to the changing rooms at half-time with the scores level at 1-1.
The home side re-took the lead shortly after the restart before Jackson bagged his sixth goal of pre-season to restore parity.
Bootle fought back and scored two more before Jack Smith added a late consolation for the Mintcakes.
"It was a bit of an up and down game but was a good workout as I expected it to be.
"There were patches where I thought we controlled the game for long periods but we got punished.
"With the exception of probably their last game they were all mistakes really."
While impressed with Jackson's recent goal scoring spree, Foster insists the striker offers much more to the team.
"He's a bit of goal machine at the moment," he said. "He has come back and made a concerted effort. He really wants to give it a bash.
"I don't think he's ever been prolific but he makes goals too and is a good focal point for the team. He is doing fantastically well and I'm really pleased for him."


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All Things Mysterious Volume Fifty-Four
Lieutenant Jones Isn't Always Right
The screech of the parrot! The monkey's incessant chatter! The hard snap of the crocodile's jaws!
Lieutenant Jones wasn't expecting this! He'd been lounging in a hammock in Vancouver, British Columbia, cold drink in one hand, intriguing international woman of mystery in the other, really enjoying life for the first time in a long while when he felt the familiar tingle that meant a mission was at hand. Before he disappeared into time and space he managed a quick farewell to the girl, saying, 'Got to run, Giselle—duty caaaaallllllls' as he faded from view.
This time, when he re-materialized, he was in exactly the same position but in a much different place--stretched out along the bottom of a canoe floating down a river!
Hoisting himself up to a sitting position, he took stock of the situation. He was in a canoe and floating down a river. That pretty much summed it up. First thing to do was ascertain just what river he was floating down. Looking around, he saw nothing but deep jungle, the occasional plume of smoke, and now and then an animal. Wild, not domestic. He must be on the Amazon!
'Yes, it's the Amazon,' the voice said. Had he said that out loud? With a start, Lieutenant Jones realized that he wasn't alone in the boat! And it was someone he knew!
'Well, if it isn't Mr. Worthington-Proudfoot! Fancy meeting you here!'
'Please call me Abner, Lieutenant. May I call you Lieutenant?'
'You may. May I ask why you are in this canoe?'
'Can you keep a secret?'
With a pained look in his eye, the Lieutenant replied, 'You wound me, sir. Discretion is a large part of my milieu.'
'In that case, sir, I will confide in you. In this jungle lurks a fountain of youth! A real one!'
'Pshaw!' scoffed the Lieutenant.
'Have you ever heard of the noted Amazonian tribal leader M'Bulu?'
'I cannot say that I have, sir.'
'He lays claim to four hundred and fifty years of life! And the reason is a small stream of youth water upon his land.'
'Rot. Men have been searching for that magic elixir for millennia, and no one has yet found it and no one ever will.'
'I beg to differ, sir. As we speak, Mr. M'Bulu is awaiting us deep in the heart of the jungle where he will show us, and allow us to sample, this ninth wonder of the world!'
Lieutenant Jones pondered this. 'Interesting. We shall see.'
The bark canoe drifted silently up the river and presently the two men saw a native on the bank improbably carrying what appeared to be a shrunken head. They paddled with their hands up to the shore and waded through the water & pebbles & rocks, pulling the vessel behind them and up onto the land. The native stood imperiously looking down at them as they struggled with the boat. Then he spoke. 'You come. To M'Bulu. You not make trouble. If trouble--' he shook the shrunken head at them. Lt. Jones and Worthington-Proudfoot looked at each other. Message received!
Then, a trek through the jungle. Worthington-Proudfoot nervously looked around him, wondering how in the heck they were going to find their canoe again to get out of here once they had found the fountain. The Lieutenant, being a trained agent of danger, was already mentally marking the trail and had noticed that they were making a large circle and would likely end up only a few dozen yards from where they started! Interesting that they would go to the trouble of such a ruse!
They came upon a clearing and both men were thinking the same thing--it was just like a scene out of an old motion picture. A bonfire, a caldron, more shrunken heads on pikes, painted natives dancing around the fire, it was all there. Hoping their heads wouldn't be shrunk more than they already were, Worthington-Proudfoot and the Lieutenant were hustled past the bubbling caldron and over to the largest tent. Their native escort knocked on the flap and received a grunt in reply. Scooching under the edge, the three men thus stood in front of the Great Leader, M'Bulu. The escort maintained a stone face but the two Westerners had to use the utmost concentration to stifle their laughter. A comically wizened old man wearing ludicrously over-the-top war paint and a huge feathered headdress sat cross-legged on the ground, mumbling. If he'd been ingesting this alleged youth formula it evidently didn't work very well! At a gesture, the two interlopers sat on the ground also and waited for M'Bulu to speak. In impeccable English he said, 'Gentlemen, I desire finance from the West in order to market my discovery in return for which you shall both have eternal youth. I have had overtures from a Mr. Kirkaby in the past, but he is missing and presumed eaten.'
Worthington-Proudfoot spoke. 'It sounds a proper investment opportunity, but before we can proceed, there must be a demonstration that the formula works.'
'Hala! Mata! Ooby-Dooby!' exclaimed the tribal leader. In an instant two warriors appeared. Tall, muscular and apparently in their twenties, they stood, silently, just inside the tent flap.
'Both of these men have seen forty-four years of the yellowing.'
Worthington-Proudfoot looked at the Lieutenant, puzzled. 'The year of the yellowing comes around every six years,' said the latter.
Worthington-Proudfoot gaped in amazement. He stammered, 'Th-these men are 264 years old?'
Lt. Jones casually strolled up to one of the warriors and politely said, 'Open your mouth, please.' He peered into the man's mouth for a few moments and then said, 'This man is not 264 years old. He approximately one-eighth that old. And he could use some mints' As Worthington-Proudfoot struggled with the mental arithmetic, the Lieutenant marched up to the old man, passing the braves, one of whom was still opened wide, and said, 'You, sir, are a fraud.'
'I will prove it to you!' And with that, in a flash the old man was out of the tent and over to the caldron from which he proceeded to scoop some of the contents out with his cupped hands and drink deeply, splashing some of it over his head and neck as well.
The Lieutenant watched bemusedly. 'Worthington-Proudfoot,' he said, 'You can tell someone's age very accurately by the condition of their teeth. That is why I knew the claims of advanced age for those men in the tent were nonsense.'
'Astounding, Jones! Utterly astounding!' gushed Worthington-Proudfoot.
A cry came from behind them. Not a cry of despair or warning or distress, but a cry much like….
In front of the caldron sat an infant no older than a few months. Beside him was a huge feathered headdress. The Lieutenant and Worthington-Proudfoot gaped in amazement at the sight right before their eyes. Then, from the big tent came a cough. The men whirled, and there were the two warriors from before. One of them, broadly smiling, removed his dentures and held them up in the firelight.
And now, run through the jungle with Lieutenant Jones, Worthington-Proudfoot, Livingstone, Stanley, lions, tigers, and bears, oh my!:::
Sent into the steaming Colombian jungle to investigate a murder, Luke Carlton stumbles on a diabolical plot that will endanger London and millions of lives!
Deep in the Amazon jungle live the Awana tribe, only 41 people strong. But 39 of them have dropped dead? Why?
As the official coroner of Laos, Dr. Siri doesn't like his job and wants to retire (again). But one more time into the breach; the good doctor is sent into the remote Laotian jungle to a remote cabin where the bodies are starting to accumulate. Why?
Questions/Comments/Immortality? firstname.lastname@example.com


text: I apologize if this has been discussed already or if this is off topic, but I'm still learning samba and I can't figure out this problem. I'm trying configure my samba/debian box to allow printing to a shared printer on a win95 machine. Any help is appreciated. In printcap: ljsaturn|HP Laserjet 6P :rm=saturn.ois.swau.edu :rp=hplj6p :sd=/var/spool/lpd/ljsaturn :mx#0 :lp=/dev/null :sh :sf I can print from another Windows machine (through the samba share \\saturn\hplj6p). However, when I'm on the samba server and type 'lpr -P hplj6p /etc/samba/smb.conf' for instance, I get the following errors: sending job 'root@delta+4' to hplj6p@localhost connecting to 'localhost', attempt 1 connected to 'localhost' requesting printer hplj6p@localhost error 'LINK_TRANSFER_FAIL' sending str '^Bhplj6p' to hplj6p@localhost job 'root@delta+4' transfer to hplj6p@localhost failed Is this a samba config problem or a printcap config problem? =========================================== Charles Lewis, Director of Administrative Computing Southwestern Adventist University, Keene, TX (817)556-4720 firstname.lastname@example.com FAX (360)397-7952 ===========================================


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The all round children's sports adventure sandal. Soft tubular X webbing for optimum fit and fast drying. Adjustable back strap for ideal foot positioning or slip-on option. Strong and very durable cushioned sole unit with anti-microbial compound to prevent odour. Comes complete with canvas carry bag.
Unique Green dot guarantee.


text: Okay, because I continue to be site challenged, my blog on David Feherty placed at the end of this posting. Don't know why. Probably because I'm stupid. This was supposed to be the opener image accompanying the main text. But I'm too skittish about trying to rearrange the works here, so let's just go with what has been set up. Please enjoy. This illustration for GOLF was for a column he penned about the hate mail he receives and how to properly write a hate letter.


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Caricatures, 3
Print advertisment created by M&C Saatchi, Spain for Arrebato Books, within the category: Recreation, Leisure.
You open a book and your life changes. Arrebato Books.
Highest Rated
I like how straight to the point the art direction is, I'm having a trouble with the reward end of the message, congrats on getting posted to AOTW
I like the concept and the illustration is cute.
Brand Design | Logo Design | Brochure Design | Website Design | Branding Packages
Lovable illustrations; heart in the right place.
(I think the Clarke visual reference is all wrong. But then, I'm an awful geek.)
That's it.
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Work Party
Cause Areas
WhenIt's flexible! We'll work with your schedule.
WhereDunne AvenueMorgan Hill, CA 95037
We need skilled contractors/remodelers to help us demo and repair various things at our teen homes!
The environment in which our residential treatment is provided is key to whether or not it succeeds. Individuals and groups who volunteer their time to make our homes functional and pleasant environments increase the quality of care provided in our residential facilities by:
**Helping recruit and retain talented staff who dedicate their lives to the kids
**Showing the kids people do care about them and their recovery
**Giving the kids an environment where they truly feel safe; and where they can open up and express their feelings to staff
All of our residences are in constant need of repair. Typical projects performed by work parties include:
Painting indoors and/or outdoors
Landscaping projects
Building projects (basketball courts, volleyball courts, sheds, etc.)
Renovation projects (Kitchen counters and cupboards, bathroom remodels)
Though Advent pays for all the supplies, it is the human element that is needed and constitutes the heart of this ministry. It is amazing what can be accomplished in a Saturday afternoon, and the effect that it can have on our work.
The impact that our volunteers have on our ministry is immeasurable. The time that they spend gives our kids a better chance at recovery and shows that there truly are people that care about them.
If you or your group would be willing to donate time and energy in order to change the lives of troubled teens, please contact Dave Moretti at (408) 281-0708 Ext. 101.
- Home Repair
Good Match For
Teens People 55+ Group
Requirements & Commitment
- Must be at least 19
- Between 3-9 hours


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About the Book
My very heart friend, Ted Kirk, is celebrating his 2 year sobriety anniversary on 7/7, which makes his sobriety anniversary 7/7/07. I have visited him 2 times since he moved back down to his heartland -- Puerto Rico. Although he grew up in a very white, small town in upstate New York, Ted has Spanish and the Latino culture in his blood and fits there.
I created this book for him as he truly loves the Island, but has never really put together an album of his chosen home.
I am so proud of my friend for his pure strength, his belief in himself and his faith in his Higher Power. Would that everyone were as straightforward, open and insightful as Ted.
Features & Details
- Category Travel
Standard Landscape, 10×8 in, 25×20 cm
40 Pages
- Publish Date May 22, 2009
- Tags San Juan, Puerto Rico, Kulebra, flowers, graffiti, church, photographs, architecture, Encanto, Isla, Doors, PR
About the Creator
I developed an interest in photography at a young age. Starting on a plastic camera with a cube flash, I upgraded to the classic Kodak Disc and finally inherited my mother's lovely old Minolta SLR workhorse. After college, I attended the Maine Film & Photographic Workshops. In 1996, I moved to New York City. As a freelance photographer in NYC, my clients included Halston, Bear USA and Weatherproof. In partnership with Joseph Cartright, I tested some of the first professional DSLRs and medium format digital backs. Moving to Minneapolis reignited my love of photography. Whether working on corporate headshots, fashion, still lifes or portraits, I bring creativity and passion to every project. My clients enjoy a memorable experience on the day, as well as a beautiful and professional end product.
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Tibetan Religion
Published: February 7, 1988
To the Editor:
Although Alexandra David-Neel was undoubtedly a very unusual and interesting person, and her extensive travels in Tibet deserve attention, Janwillem van de Wetering's review of ''Forbidden Journey'' by Barbara M. Foster and Michael Foster (Jan. 10) was marred with errors on Tibetan Buddhism.
As a Tibetan Buddhist, I have been taught by lamas and my parents to practice compassion. I have never heard of tantric Buddhism, though rich in ritual and symbolism, referred to as following a ''demonic way.'' Mr. van de Wetering's statement gives the impression that Tibetan tantric Buddhism is an extremely negative or evil practice. This totally contradicts what Tibetan Buddhism is about.
It is unfortunate that The Book Review did not find a more informed person to review this book. There are numerous students and scholars of Tibetan Buddhism in America who would never have made such an irresponsible remark. PUNTSOG N. TETHONG New York Janwillem van de Wetering replies:
Tantric Buddhism, or Vajrayana, has to do with spells and ritual first taught in Tibet by the eighth-century Indian master Padmasambhava. The discipline aims at helping us to evoke an inward drama of self-development and spiritual growth, in which we do battle with a number of demons. Mr. Tethong objects to my use of the word ''demonic.''
When I studied with Lama Trungpa Rimpoche at his retreat in Scotland in the 1960's, I was delighted to hear that even the most fearful demons in tantric Buddhism ultimately symbolize compassion. Our struggles with these dark forces from the subconscious ultimately result in providing the clearest light, in which opposing opinions merge and reinforce each other. If this basic teaching is true, my irresponsible remark and Mr. Tethong's corrective slap may serve to enhance an essential Buddhist beauty.