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Diamond coated quartz(DQ) electropositive filters were compared with a few commercially available electropositive filters. The zeta potential of all the filters were measured and it was found that DQ had higher positive zeta potential over a wide pH range. Dye retention tests, using acid black II dye, performed on all the filters showed DQ to have higher retention. The study clearly showed that, under laboratory conditions, DQ has better performance compared to many commercial electropositive filters. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work a strategy to grow diamond on β-Ga 2 O 3 has been presented. The ζ-potential of the β-Ga 2 O 3 substrate was measured and it was found to be negative with an isoelectric point at pH ∼ 4.6. The substrates were seeded with mono-dispersed diamond solution for growth of diamond. The seeded substrates were etched when exposed to diamond growth plasma and globules of gallium could be seen on the surface. To overcome problem ∼ 100 nm of SiO 2 and Al 2 O 3 were deposited using atomic layer deposition. The nanodiamond seeded SiO 2 layer was effective in protecting the β-Ga 2 O 3 substrate and thin diamond layers could be grown. In contrast Al 2 O 3 layers were damaged when exposed to diamond growth plasma. The thin diamond layers were characterised with scanning electron microscopy and Raman spectroscopy. Raman spectroscopy revealed the diamond layer to be under compressive stress of 1.3–2.8 GPa. [Display omitted] [ABSTRACT FROM AUTHOR]

This work presents an easy-to-use microwave split dielectric resonator (MSDR) for X-band dielectric measurements of free-standing unpolished poly-crystalline diamond (PCD). PCD grown with varying CH 4 /H 2 and O 2 / CH 4 /H 2 in the gas phase show stark differences in dielectric loss. Low microwave dielectric loss PCD is found for CH 4 /H 2 concentrations of less than 5% while PCD grown with O 2 show very high loss tangents. Vacuum annealing introduces non-diamond carbon (NDC) impurities which increases the loss, however, even after significant discolouration the loss is still lower than the O 2 grown PCD. The loss mechanism of O 2 grown PCD is likely due to a high concentration of grain boundaries and grain boundary hopping conduction mechanisms as opposed to high concentrations of NDC impurities. [Display omitted] [ABSTRACT FROM AUTHOR]

The chemical nature of the chemical mechanical polishing of diamond has been examined by adding various redox agents to an alkaline SF1 polishing slurry. Three oxidizing agents, namely hydrogen peroxide, potassium permanganate and ferric nitrate, and two reducing agents, oxalic acid and sodium thiosulfate, were added to the SF1 slurry. Oxalic acid produced the fastest polishing rate while hydrogen peroxide had very little effect on polishing, probably due to its volatile nature. X-ray photoelectron spectroscopy (XPS) reveals little difference in the surface oxygen content on thesamples polished using various slurries. This suggests that the addition of redox agents do not increase the density of oxygen containing species on the surface but accelerate the process of attachment and removal of Si or O atoms within the slurry particles to the diamond surface. [ABSTRACT FROM AUTHOR]

This study focuses on the self-assembly and subsequent diamond growth on SiO 2 buffered lithium niobate (LNO) and lithium tantalate (LTO) single crystals. The zeta-potential of LNO and LTO single crystal were measured as a function of pH. They were found to be negative in the pH range 3.5–9.5. The isoelectric point for LNO was found to be at pH ∼ 2.91 and that of LTO to be at pH ∼ 3.20. X-ray photoelectron spectroscopy performed on the surfaces show presence of oxygen groups which may be responsible for the negative zeta potential of the crystals. Self-assembly of nanodiamond particles on LTO and LNO, using nanodiamond colloid, were studied. As expected, high nanodiamond density was seen when self-assembly was done using a positively charged nanodiamond particles. Diamond growth was attempted on the nanodiamond coated substrates but they were found to be unsuitable for direct growth due to disintegration of substrates in diamond growth conditions. A ∼ 100 nm thick silicon dioxide layer was deposited on the crystals, followed by nanodiamond self assembly and diamond growth. Thin diamond films were successfully grown on both coated crystals. The diamond quality was analysed by Raman spectroscopy and atomic force microscopy. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, the reaction dynamics of hydrogen termination of nanodiamond annealed at low temperature (500 °C) in molecular hydrogen atmosphere is reported. In-situ residual gas analysis of nanodiamond particles (4–5 nm) during annealing/hydrogenation indicates C 3 -radical desorption which incites a free radical reaction through the reduction of molecular hydrogen to atomic hydrogen. Consequently, as released atomic hydrogen facilitates C H adsorption on the surface of nanodiamond which was confirmed using infrared spectroscopy. This explains how nanodiamond particles can play a key role in hydrogen (H 2 ) dissociation and be terminated by the hydrogen (H) at relatively low temperature. [ABSTRACT FROM AUTHOR]

Patterning a surface by scratching at micro-nano scale requires precise instrumentation strategies for generation of accurate patterns which are used in variety of surfaces ranging from bacteria resistant surfaces to water repellent ones. The scratching action leads to temperature rise of tool tip causing expansion of tool and work surface. This results in positioning inaccuracies and surface defects of the machined work. In this work a fiber Bragg grating sensor (FBG) is used to record the temperature rise at the tool tip under different scratching/cutting speeds. The surface integrity of the patterned work was evaluated after machining using a profilometer. The optimized value of cutting speed for minimum inaccuracy and minimum burr was found using Lagrangian multiplier based technique. This work thus ensures real time control of scratching speed based on tool tip temperature variations only, which finally results in better surface integrity of patterned profile. [ABSTRACT FROM AUTHOR]

Abstract: In this work we present the fabrication and characterization of superconducting nano-mechanical resonators made from nanocrystalline boron doped diamond (BDD). The oscillators can be driven and read out in their superconducting state and show quality factors as high as 40,000 at a resonance frequency of around 10MHz. Mechanical damping is studied for magnetic fields up to 3T where the resonators still show superconducting properties. Due to their simple fabrication procedure, the devices can easily be coupled to other superconducting circuits and their performance is comparable with state-of-the-art technology. [Copyright &y& Elsevier]

Abstract: In order to meet the growing demand of direct patterning over solid surfaces in micro-nano scale, a pantograph based mechanism has been developed. This mechanism ensures the precision positioning of tool tip while retaining the tool tip orientation irrespective of scratch depth unlike cantilever mechanism used in AFM systems. This mechanism provides one DOF motion in XZ plane at ¼ of the motion induced at driving point by the linear actuator. The design of pantograph mechanism including analysis performed on motion and force transfer between actuator and the tool tip is presented. [Copyright &y& Elsevier]

A coplanar waveguide resonator (CPR) is presented for kinetic inductance (L k) and penetration depth (λ L) measurements of superconducting boron doped nanocrystalline diamond (B-NCD) at microwave frequencies of 0.4 to 1.2 GHz and at temperatures below 3 K. Using finite element modelling and experimental measurements, this work demonstrates that thin granular B-NCD films (thickness d ≈ 500 nm) on Si have a large penetration depth ( λ L ≈ 3.8 μm), and therefore an associated high kinetic inductance per square ( L k , □ ≈ 670 to 690 pH/ □). These values are much larger than those typically obtained for films on single crystal diamond, which is likely due to the high granularity of the nanocrystalline films. Based on the measured Q factors of the structure, the calculated surface resistance is found to be around ≈ 1 to 6 μΩ at T < 2 K in the 0.4 to 1.2 GHz range, demonstrating the potential for granular B-NCD for high quality factor superconducting microwave resonators and highly sensitive kinetic inductance detectors. [Display omitted] [ABSTRACT FROM AUTHOR]

• Optimization of process parameters utilizing response surface methodology. • The optimized processing efficiency achieved 1.56 cm/h, with a roughness of 0.76 µm. • Successful machining of 4-inch diamond substrates. Microsecond-pulsed fiber laser was employed for the surface planarization processing of large-scale freestanding polycrystalline diamond. The effects of process parameters, including rotational processing speed, pulse duration, duty cycle, and line spacing, on the processing outcomes were investigated using statistical approach, specifically, response surface methodology (RSM). As for surface roughness (R), the influence of pulse width was more important than duty cycle and line spacing, while rotational processing speed hardly presented significant influence; however, for material removal rate (S), the impact of line spacing is most pronounced. The laser processing of diamond led to a graphitization, while the observed sputtering of small particles at the laser focus identified as the primary cause for high removal rates. The developed high-energy laser planarization system demonstrated capability in processing of large 4-inch diamond wafers, presenting an effective technology for achieving both higher-quality surfaces and elevated removal rates simultaneously in comparison to mechanical grinding methods. [ABSTRACT FROM AUTHOR]

Conductive diamond has been recognized as a promising electrode material for supercapacitors due to its excellent stability and broad electrochemical potential window. To enhance the performance of diamond-based supercapacitors, this study focuses on two key strategies: incorporating redox-active species on the electrodes and/or in the electrolytes to increase the capacitance, and constructing asymmetric supercapacitors to expand the operating voltage range. In this context, pseudocapacitive Co 3 O 4 @boron doped diamond (BDD) and Bi–Bi 2 O 3 @BDD were synthesized using metal-organic framework (MOF) decorated BDD of Co-MOF@BDD and Bi-MOF@BDD as precursor materials, respectively. An aqueous asymmetric supercapacitor was then assembled using a pseudocapacitive electrode/redox electrolyte system of Co 3 O 4 @BDD | 3.0 M KOH+0.05 M K 3 Fe(CN) 6 /K 4 Fe(CN) 6 as the positive compartment, and Bi–Bi 2 O 3 @BDD | 3.0 M KOH as the negative compartment. The resulting device demonstrated a wide operating voltage of 1.7 V, a maximal energy density of 10.0 Wh L−1 at a power density of 333.2 W L−1. The remarkable performance can be attributed to the Faradaic redox reactions involving [Fe(CN) 6 ]3-/4-, Co3+/Co4+, Bi0/Bi2+/Bi3+ in the electrode materials and electrolytes. This work presents a novel way for fabricating aqueous supercapacitors with high voltage, high energy and power densities, offering significant potential for various energy storage applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The quality of polycrystalline diamond films is heavily dependent on the nucleation and early stages of growth, making the ability to monitor these early stages highly desirable. Spectroscopic ellipsometry (SE) allows for real-time monitoring of the thickness, composition, and morphology of films with sub-nanometre precision. In this work, ex-situ SE spectra were used to develop an optical model for film characterisation, which was then applied to in-situ data. The coalescence of individual crystallites into a single film was observed through a parabolic decrease in void content followed by peaks in sp2 content and surface roughness. These observations were validated using ex-situ Raman spectra and AFM images of samples grown for durations between 5 and 30 min. The model was also used to investigate the impact of varying the methane concentration, finding that a higher methane fraction resulted in earlier coalescence and a higher peak in sp2 content. This work demonstrates that SE is a powerful tool for monitoring and optimisation of the critical early stages of polycrystalline diamond growth. [Display omitted] [ABSTRACT FROM AUTHOR]

It is important to account for variance in substrate temperature during microwave plasma-enhanced chemical vapour deposition (MPECVD) nanocrystalline diamond growth, as this has a significant impact on the uniformity of the grown film. In this work, an in-situ method of mapping the substrate temperature under MPECVD growth conditions is demonstrated, employing a mirror galvanometer to scan the field of view of a dual-wavelength pyrometer across the substrate. Temperature maps generated were compared to plasma electron densities simulated using a finite element model. An increase in temperature and simulated plasma density were seen towards the centre of the holder. The properties of nanocrystalline diamond films were mapped using ex-situ Raman spectroscopy and spectroscopic ellipsometry (SE). A greater SE-measured bulk thickness and bulk sp3 fraction, as well as a greater first-order diamond Raman intensity and lower full width at half maximum were seen in the higher-temperature central region, demonstrating the impact of substrate temperature inhomogeneity during growth. The temperature mapping technique demonstrated allows easy evaluation of the impact of substrate holder design, microwave power and chamber pressure on substrate temperature homogeneity, and therefore optimisation of growth conditions for uniform diamond film growth. [Display omitted] [ABSTRACT FROM AUTHOR]

We measured the bulk effective complex permittivities of various nanodiamond powders, of different average particle sizes (in the range from about 10 nm to 1 μm) using a microwave cavity perturbation technique at 2.49 and 5.72 GHz. We observed an increased permittivity with decreasing particle size, both in terms of the polarisation and microwave loss. In separate experiments we used Raman Spectroscopy to determine the amount of surface sp 2 carbon present in the same samples. We also used X-Ray Diffraction to estimate the crystallite size and to determine the chemical compositions, whilst we measured overall particle size using Field Emission Scanning Electron Microscopy. We interpret the increased permittivity in the smaller particles as being due to larger volume fraction of sp 2 hybridised carbon material, and verify this by comparison with a simple model that predicts that the amount of microwave absorption for fixed powder volume should be inversely proportional to the average particle size. Hence, we conclude that the microwave method is a fast, accurate and non-invasive way of estimating the relative proportion of sp 2 carbon in nanodiamond samples. [ABSTRACT FROM AUTHOR]

Abstract: The demonstration that Nanocrystalline Diamond (NCD) can retain the superior Young’s modulus (1100GPa) of single crystal diamond twinned with its ability to be grown at low temperatures (<450°C) has driven a revival into the growth and applications of NCD thin films. However, owing to the competitive growth of crystals the resulting film has a roughness that evolves with film thickness, preventing NCD films from reaching their full potential in devices where a smooth film is required. To reduce this roughness, films have been polished using Chemical Mechanical Polishing (CMP). A Logitech Tribo CMP tool equipped with a polyurethane/polyester polishing cloth and an alkaline colloidal silica polishing fluid has been used to polish NCD films. The resulting films have been characterised with Atomic Force Microscopy, Scanning Electron Microscopy and X-ray Photoelectron Spectroscopy. Root mean square roughness values have been reduced from 18.3nm to 1.7nm over 25μm2, with roughness values as low as 0.42nm over ∼0.25μm2. A polishing mechanism of wet oxidation of the surface, attachment of silica particles and subsequent shearing away of carbon has also been proposed. [Copyright &y& Elsevier]

Joule self-heating is the main obstacle limiting the performance of GaN power devices. A nano-diamond (NCD) film for near-junction heat transfer has been approved as an effective approach to overcome this issue. In the present study, we developed a scheme to deposit a smooth NCD film with high thermal conductivity (TC) over the surface of GaN. First, a 10-nm Si 3 N 4 was deposited as the protective layer of GaN, followed by electrostatic seeding to improve nucleation density and particle distribution uniformity. Second, argon and gradient methane gas were introduced to prepare the NCD film based on nucleation and the growth period. The resulting thickness of the NCD film was 150 nm with a roughness of about 20 nm. The thermal boundary resistance (TBR eff) between GaN and NCD film was only 12.8 ± 0.64 m2K/GW, whereas the TC of the NCD film was 200 ± 40 W m−1 K−1, which was similar to the theoretical prediction. Thus, it could be inferred that the high crystallinity of the NCD film contributes to the low TBR eff and high TC through the whole NCD layer. [Display omitted] [ABSTRACT FROM AUTHOR]

Diamond is a material that offers potential in numerous device applications. In particular, highly boron doped diamond is attractive due to its superconductivity and high Young's Modulus. The fabrication of stable, low resistance, ohmic contacts is essential to ensure proper device function. Previous work has established the efficacy of several methods of forming suitable contacts to diamond at room temperature and above, including carbide forming and carbon soluble metallisation schemes. Herein, the stability of several contact schemes (Ti, Cr, Mo, Ta and Pd) to highly boron doped nanocrystalline diamond was verified down to the cryogenic temperatures with modified Transmission Line Model (TLM) measurements. While all contact schemes remained ohmic, a significant temperature dependency is noted at T c and at the lowest temperatures the contact resistances ranged from Ti/Pt/Au with (8.83 ± 0.10) × 10−4 Ω cm to Ta/Pt/Au with (8.07 ± 0.62) × 10−6 Ω cm. [Display omitted] [ABSTRACT FROM AUTHOR]

Boron doped diamond (BDD) has been widely used in various electrochemical fields, due to its unique physical and chemical properties. However, the investigation of the electrochemistry of bi-element incorporated diamond, especially the variation of surface components after nitrogen incorporation into BDD and the corresponding electron transfer of inner-sphere and outer-sphere redox probes is still lacking. Here, the electrochemistry of nitrogen and boron bi-element incorporated diamond (NBD) is thus investigated in both inner and outer redox systems, namely in [Fe(CN) 6 ]3-/4- and [Ru(NH 3) 6 ]3+/2+ solutions. On the NBD electrode, enhanced electrochemical responses are achieved for both outer- and inner-sphere redox reactions. Such enhancement originates from the enrichment of C O groups and the increased amount of sp2 species in the NBD film. Moreover, the nitrogen and boron atoms incorporated in diamond modulate the surface polarities and the electronic states of diamond. Based on the enhanced and stable capacitance of the NBD electrode, its electrochemical energy applications are explored by assembling its supercapacitor as a case study. This work reveals the influence of sp2 species and oxygen-contained function group on the electrochemistry of bi-element incorporated diamond films and reveals their potential electrochemical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Diamond heat-spreaders for gallium nitride (GaN) devices currently depend upon a robust wafer bonding process. Bonding-free membrane methods demonstrate potential, however, chemical vapour deposition (CVD) of diamond directly onto a III-nitride (III–N) heterostructure membrane induces significant thermal stresses. In this work, these thermal stresses are investigated using an analytical approach, a numerical model and experimental validation. The thermal stresses are caused by the mismatch in the coefficient of thermal expansion (CTE) between the GaN/III-N stack, silicon (Si) and the diamond from room temperature to CVD growth temperatures. Simplified analytical wafer bow models underestimate the membrane bow for small sizes while numerical models replicate the stresses and bows with increased accuracy using temperature gradients. The largest tensile stress measured using Raman spectroscopy at room temperature was approximately 1.0 ± 0.2 GPa while surface profilometry shows membrane bows as large as 58 μm. This large bow is caused by additional stresses from the Si frame in the initial heating phase which are held in place by the diamond and highlights challenges for any device fabrication using contact lithography. However, the bow can be reduced if the membrane is pre-stressed to become flat at CVD temperatures. In this way, a sufficient platform to grow diamond on GaN/III-N structures without wafer bonding can be realised. Image 1 [ABSTRACT FROM AUTHOR]

A series of Dy3+ doped aluminoborosilicate glasses with general formula 20SiO 2 -(40-x) B 2 O 3 –10Al 2 O 3 –20NaF 2 –10ZnO-xDy 2 O 3 (x = 0, 0.1, 0.5, 1.0. 1.5, 2.0 and 2.5 mol %) were prepared by melt-quenching method. The FTIR analysis confirms the presence of stretching and bending vibrations of BO 4 , BO 3 and SiO 4 units in the prepared glasses. DTA results show that Tg is decreasing with addition of Dy3+ ions in the glass system. Theoretically calculated mechanical properties such as elastic modulus, bulk modulus, shear modulus and Poisson's ratio suggest the increase in mechanical stability of glasses with dysprosium addition. Also experimental analysis carried out using Vicker's microhardness suggests glass stability with applied loads. Absorption spectrum shows twelve bands that exist due to transition from 6H 15/2 level to different excited levels. Nephelauxetic ratio and bonding parameter calculated shows decreasing ionicity of glasses with increase in Dy3+ ions. Judd-Oflet parameter calculated for all the glasses follow the trend Ω 6 > Ω 4 > Ω 4. Luminescence study shows three emission peaks having transitions from 4F 9/2 → 6H 15/2 (blue), 4F 9/2 → 6H 13/2 (yellow) and 4F 9/2 → 6H 11/2 (red). Radiative parameters calculated suggest higher stimulated emission cross-section for present glasses having 4F 9/2 → 6H 13/2 transition. The decay measurement for all the glass samples were recorded with an excitation at 350 nm and monitoring emission at 575 nm corresponding to the 4F 9/2 → 6H 13/2 transition and decay curves were fitted to bi-exponential fit. The CIE colour chromaticity coordinates were determined using CIE chromaticity diagram and the values were found to be in close proximity with the standard white light (0.33. 0.33) for all the glasses. Further colour correlated temperature values were found to lie in the near bright white region with CCT around ~4000 K. • Various concentrations of Dy3+-doped SiO 2 –B 2 O 3 –Al 2 O 3 –NaF–ZnO glasses were synthesized. • Mechanical properties of these glasses were studied along with experimental analysis. • Optical bandgap and Urbach energy of these glasses were calculated. • Energy transfer mechanism and radiative parameters were studied. • All Dy3+- doped glasses CIE (x, y), and CCT values represent the bright white light region. [ABSTRACT FROM AUTHOR]

Transparent 10BaO-20ZnO-20LiF-(50- x) B 2 O 3 - x Er 2 O 3 glasses with x = 0, 0.1, 0.5, 0.7 and 1 mol % were synthesized using melt-quench method. Their amorphous nature was confirmed from X-Ray Diffraction (XRD). The glasses were irradiated with 3 kGy gamma dose, among which the sample with 0.7 mol % Er 2 O 3 doping showed the highest integrated thermoluminescence (TL) intensity. The dose-response was evaluated by irradiating the sample with 0.25- 30 kGy gamma doses. The highest integrated TL intensity was obtained at 3 kGy dose. Fourier Transform Infrared (FTIR) spectra of the 0.7 mol % Er 2 O 3 doped glass after 3 kGy gamma irradiation predicted the creation of new bonds and rise in the Non-Bridging Oxygens. UV–Vis–NIR absorption spectra recorded after 3 kGy gamma irradiation accounted for the formation of color centers due to an increase in the total absorption of the glass, a decrease in the bandgap and an increase in the Urbach energy. The sample exhibited good linearity in the 0.25 to 3 kGy range with high sensitivity of 27021 counts g-1kGy-1 and a minimum detectable dose of 0.201 kGy. TL signal faded by just 4% after a week of storage. The annealing condition for reusability and the effective atomic number of the glass were examined. Trap parameters like activation energy, frequency factor and lifetime, determined using Computerized Glow Curve Deconvolution (CGCD) and Chen's peak shape methods supported the low fading of the sample. Overall, the remarkable TL dosimetry characteristics present the usefulness of the titled glass system in radiation processing of food products and high-dose (0.25 to 3 kGy) gamma environment. [ABSTRACT FROM AUTHOR]

Diamond-based X-ray luminescent composites are robust materials to be used in synchrotrons and free-electron lasers to detect and visualize high-intensity X-ray beams. Such composites consist of luminescent rare-earth (RE) particles embedded into an X-ray transparent diamond matrix. In this work, polycrystalline diamond composites with embedded particles of EuF 3 , SrF 2 :Eu and YAG:Ce were grown by microwave plasma CVD using diamond seeds with an average particle size difference of two orders of magnitude: from 5 nm up to 500 nm, with positive and negative zeta potentials. The structure, phase composition, and luminescent characteristics of the resulting composite films were investigated and analyzed. We found that various particle types can be better-suited for different composites, and the exact seeding should be selected on the case-by-case basis. The direct comparison of various diamond-based composites, grown in the identical CVD conditions but with various luminescent powders, show that YAG:Ce particles in diamond allow achieving a brighter photoluminescence (PL) in comparison to Eu-based fluorides. However, the set of fluoride powders doped with Eu3+ ions allow obtaining unusually narrow (FWHM = 0.9 nm) and intensive line near 611 nm in PL spectra, which might be better-suited for detection and characterization applications rather than a broad peak of Ce with FWHM ≈ 120 nm. [Display omitted] [ABSTRACT FROM AUTHOR]

The impact of plasma inhomogeneity on the sp 2 content of thin film (∼micron) boron doped diamond (BDD) electrodes, grown using microwave chemical vapour deposition (MW-CVD) under different methane (CH 4 ) concentrations (1% and 5%), is investigated. The sp 2 surface content (critical for interpreting electrochemical data) is comparatively assessed using a variety of electrochemical measurements: capacitance; solvent window analysis and quinone surface coverage. For all growths, distinctive regions containing appreciably differing amounts of sp 2 carbon are identified, across the wafer. For example, on the 1% CH 4 wafer, some areas exhibit electrochemical signatures indicative of high quality, minimal sp 2 content BDD, whereas others show regions comprising significant sp 2 carbon. Note Raman microscopy was unable to identify these variations. On the 5% CH 4 wafer, no region was found to contain minimal levels of sp 2 carbon. Changes in sp 2 content across the BDD films indicates spatial variations in parameters such as temperature, methane and atomic hydrogen concentrations during growth, in this case linked directly to the use of a commonly employed multi-moded (overmoded) chamber for MW-CVD BDD synthesis, operated under low power density conditions. Varying sp 2 levels can have significant impact on the resulting electrochemical behaviour of the BDD. [ABSTRACT FROM AUTHOR]