Masking Properties Research Articles

Spiced-marinating injection brine effect on the entire pork quality

Searching for new alternatives to commercialize pork from entire male pigs that could be affected by a boar taint sensory defect would be adequate. In this study, two different marinade mixtures (additives, salt, white wine plus different spices for mixture 1 and 2) were injected into pork loin pieces from castrated (C1 and C2) and entire male pigs (E1 and E2) with a high boar taint level (5.51 µg.g−1 AND and 0.73 µg.g−1 SKA) to evaluate their effect on the physicochemical and sensory quality of pork, and to assess their boar taint masking properties. To achieve this, physicochemical and sensory analyses with trained panellists were carried out. Marinated meat showed some differences in colour and a reduction in cooking losses. Mixture 2 achieved the best boar taint masking effect, due to spices content mainly nutmeg and ginger, and other ingredients such as white wine. In conclusion, marinating pork from entire male pigs can contribute to achieving an acceptable quality standard.

SILENCER-COOLER AS A MEANS OF REDUCING THE EXTERNAL NOISE OF THE "TRITON-01" ARMORED VEHICLE

The problem of camouflage of military equipment is extremely urgent. In this work, a certain improvement of masking properties is proposed by reducing the level of external noise for the Triton-01 armored car. The Triton-01 armored car is equipped with a remote-controlled combat module, a reconnaissance and target detection system, and an information transmission system. This armored car has a number of sources of noise, among which the exhaust system is quite powerful, that is, the noise of exhaust gases. This type of noise is reduced by appropriate mufflers. As practical studies show, at the moment the noise of exhaust gases of military equipment is not sufficiently suppressed by mufflers. We offer a developed complex muffler consisting of two mufflers connected in series: a single-chamber reactive muffler and a cooling muffler. A muffler-cooler of exhaust gas noise has been developed, which contains a hermetic housing filled with refrigerant, inlet and outlet nozzles and a gas pipe for exhaust gases, made straight along the axis of the muffler and with shaped walls that provide the maximum perimeter in a given section. Passing through the gas pipeline, the exhaust gases give off heat to the cooling medium through its walls. The developed one is structurally different from the existing silencers-coolers: the contact area of the cooling liquid with the surface of the silencer is significantly increased. As a result of the cooling of exhaust gases, the speed of movement of the latter is significantly reduced, and as a result, the level of acoustic (noise) vibrations present in these gases. The work calculates the cooling system, which should cool the exhaust gases. A proposal was made to use a refrigerant that is prepared in advance for the combat departure of an armored vehicle. There are possible options for preparing the refrigerant: the armored car itself or a specialized mobile installation.

Evaluation of the Effectiveness of Protecting Three-Dimensional Printers against Acoustic Infiltration

Three-dimensional printers are increasingly used in design work when designers want to quickly and inexpensively verify their solutions. However, based on the sounds made by the printer during its operation, it is possible to determine the shape of the printed object with quite high accuracy. The above fact should be taken into account if information about this object needs to be protected. The article presents a way to protect a 3D (Three-Dimensional) printer against acoustic infiltration. The research study was carried out using the Zortrax M200 Plus printer for LPD (Layer Plastic Deposition) technology, which is an equivalent of the popular FDM/FFT (Fused Deposition Modeling/Fused Filament Fabrication) 3D printing technology using thermoplastic. The frequencies of acoustic signals related to the operation of stepper motors and the printing platform were identified. These signals enable the reconstruction of the shape of printed objects. It was examined whether the appropriate type and required level of masking noise can be selected for a given type of printer in order to protect it against acoustic infiltration. The masking properties of selected color noises were compared with those of white noise and the optimal intensity levels were determined at which the acoustic safety of the tested printer can be ensured. It was underlined that the research results refer only to the tested printer and should not be generalized to other types of 3D printers.

Role of Nanotechnology in Taste Masking: Recent Updates.

One of the important parameters in the case of dosage form is taste. Most of the drugs available in oral dosage form have an unpleasant taste which leads to patient incompliance and affects the success ratio of products in the market. Geriatric and paediatric patients suffer more with the bitter taste of medicines. According to the studies reported, it is found that 50% of the population have the problem swallowing tablets, especially the pediatric and geriatric population. Masking the taste of bitter drugs has become necessary in the pharmaceutical field and increasing interest of researchers to develop various methods for masking the bitter taste of drugs. Five major tastes, felt by our tongue are salt, sour, sweet, bitter, and umami. When the drug dissolves with saliva, drug molecules interact with taste receptors present on the tongue and give taste sensations. Although, many solid oral dosage forms like pills, and tablets have an additional advantage of masking and encapsulation of bitter taste drugs; however, they might not be effective for children because they may or may not swallow pills or tablets. There are various other methods that mask the bitter taste of drugs such as the addition of sweeteners and flavouring agents, granulation, coating, inclusion complexes, extrusion method, ion-exchange resins, etc, discussed in the first section of the article. The second part of this article consists of various nanotechnology-based drug delivery systems that were fabricated by researchers to mask the bitter taste of drugs. A brief of recent literature on various nanocarriers that were fabricated or developed for taste masking has been discussed in this part. A better understanding of these methods will help researchers and pharmaceutical industries to develop novel drug delivery systems with improved taste masking properties.

Formulation And Evaluation Of Berberine Hydrochloride Film Coated Tablet

The purpose of the present study was to formulate and evaluate Berberine HCl Film coated tablet. Preformulation studies of API were done. The film coated tablets have advantages over conventional oral dosage forms, film coated tablet also influences the release of drug after compression. Film coating also help in making the tablet with good taste masking properties and excellent mechanical strength. It was revealed in the study that cellulosic coating materials were unable to resist the compression forces whereas hydroxypropyl methyl cellulose co-polymers resist the forces. Furthermore, aqueous dispersions of hydroxypropyl methyl cellulose co-polymers showed high flexibility as that of cellulosic materials thereby providing resistance from destructive compressional forces. The Preformulation characteristics were done as per the Pharmacopeial specifications. The drugs and excipients compatibility studies were carried out by FT-IR spectroscopy. Various pre-compressional parameters like bulk density, tapped density, compressibility index and Hausner’s ratio and post-compressional parameters like weight variation, thickness, hardness, friability, disintegration time and drug release were studied. The spectra elucidate that there was no interaction between Drug and excipients. In order to achieve the best optimized product, five different formulations were developed using diluents, binder, glidant, lubricant, and different concentrations of super-disintegrant. The tablets were prepared by using wet granulation method. Optimization was done and it was found that release profile was found to be best with super-disintegrant that is Crospovidone and Enhance DT. Protectab HP-1 coating was done on Berberine HCl tablets. In-vitro release was carried out in medium 6.8 pH Phosphate buffer. The formulation F-5 was showed better drug release and selected as an optimized formulation.

Selective Copper Electroplating on Patterned Self-Assembled Monolayers for Photovoltaic Applications

The photovoltaic industry is expected to consume 30–50% of the global silver supply by 2030, indicating the need for using other materials for solar cell metallization processes. We report herein a low-cost and scalable mask of phosphonic acid (PA) self-assembled monolayers (SAMs) on indium tin oxide (ITO) for nickel and copper electroplating on solar cells. Octadecylphosphonic acid and 12-azidododecylphosphonic acid were deposited using different procedures and characterized by cyclic voltammetry and etching resistance tests to assess the barrier properties of the SAMs. It was found that the PA chemical functionalization and the deposition method strongly affect the masking properties of SAMs. The underlying PA binding modes were investigated using attenuated total reflectance Fourier transform infrared spectroscopy, which revealed that the heterocondensation reaction between 12-azidododecylphosphonic acid and ITO was promoted during heating. Patterning of SAMs was performed using UV-C radiations to achieve selective electroplating of nickel and copper on ITO.

Evaluations of the Annoyance Effects of Noise

Noise is defined as audible sound that disrupts silence and causes annoyance. Such annoyance is traditionally assessed by the A-weighted sound pressure level of noise, roughly corresponding to the level of perceived loudness. However, the A-weighted scale is inapplicable for analyzing tonal, pulsed, and predominantly low-frequency noise; therefore, methods have been developed for calculating noise loudness in linear units, sones, which take into account not only auditory sensitivity, but also masking properties and auditory temporal effects. The existence of noise reduction limits and their informational significance have led to other methods for assessing noise annoyance. Annoyance, in addition to loudness, is caused by such subjective noise qualities as sharpness, roughness, fluctuation strength, tonality, etc. Units of measurements have been defined for these and calculation methods developed. Taking such qualities into account, a metric of short-term psychoacoustic annoyance (PAA) has been proposed, which is valid for many types of noise. Another method for evaluating PAA includes conducting an auditory examination and constructing a mathematical model that relates the rank of auditory annoyance to the measured subjective qualities of the noise. The resulting model helps to identify the causes of annoyance (subjective annoying qualities); develop work plans aimed at noise suppression, the formation of pleasant noise by machines and mechanisms; and control changes in the rank of annoyance in the implementation of such plans. This paper compares different methods for assessing the annoyance caused by noise recorded in Moscow subway cars.

Formulation of Levocetirizine-Loaded Core-Shell Type Nanofibrous Orally Dissolving Webs as a Potential Alternative for Immediate Release Dosage Forms.

Several applications of nanofiber-based systems are based on their corresponding functionality-related properties, which often cannot be satisfied by a fiber web with a monolithic structure because of the various physicochemical properties and amounts of embedded compounds. Therefore, one of the main directions in the development of fiber systems is creating core–shell type complex fiber structures that can provide application-specific properties to the fiber matrix. The present study aimed to formulate levocetirizine-loaded core–shell type hydrophilic polymer-based fibrous systems. The core phase contained the antihistamine levocetirizine, while the permeation enhancer (Na-taurocholate), the local pH regulator (citric acid), and the cyclodextrin used as a taste masking agent were included in the shell phase of the fibrous formulation. Scanning electron microscopy images indicated that a randomly oriented homogeneous fibrous structure was obtained, while the Raman mapping and chemometric analysis confirmed the partially formed core–shell structure. A fast release rate of the antihistamine drug from the complex structural fibrous system was obtained (within 1 min complete dissolution can be observed) due to its increased surface area to volume ratio and its more favorable wettability properties, which consequently allows for more erosion. The masking properties against the unpleasant bitter taste of API of the formulated complex nanostructure were confirmed by the results of the electronic tongue. The formulated complex nanostructure enabled fast and complete release of the API, providing a potential enhancement in the rate and extent of absorption while masking the unpleasant taste of levocetirizine, which has a high impact on the patient adherence. All in all, the results show that the developed orally dissolving fibrous web formulation can be a potential alternative to the commercially available orally disintegrating tablets.

Masking properties of two ceramic materials with different thickness as a Monolithic restoration

Masking properties of two ceramic materials with different thickness as a Monolithic restoration

Fast Melt Cocoa Butter Tablet: Effect of Waxes, Starch, and PEG 6000 on Physical Properties of the Preparation.

A fast melt tablet (FMT) is well regarded as an alternative delivery system that might help resolve a patient’s non-compliance issue. The main objective of this study was to develop a cocoa butter-based FMT. Additives, namely 5–15% of PEG 6000, beeswax, paraffin wax, and corn starch, were incorporated into the cocoa butter-based FMT to study the effects of these additives with the physical characteristic of a cocoa butter FMT. An optimum-based formulation was chosen according to the desired hardness and disintegration time and the taste masking property achieved with the model drug—dapoxetine. The analysis demonstrated that incorporating beeswax (15%) and paraffin wax (15%) could prolong the disintegration time by at least two-fold. On the contrary, the presence of corn starch was found to cause an increase in the hardness and reduction of the disintegration time. The disintegration mechanism might be presumed due to the synergistic effect of starch swelling and cocoa butter melting. The hardness value and in vitro disintegration time of the optimum formulation were recorded at 2.93 ± 0.22 kg and 151.67 ± 6.98 s. In terms of dissolution, 80% of dapoxetine was released within 30 min and the dissolution profile was comparable to the innovator product. The formulation was palatable and stable for at least 1 year. The exposure of the FMT formulation at 30 °C for 12 months was reported to be stable. Along with the sound palatability profile and high drug load capacity, the current formulation possesses the desired characteristics to be scaled up and marketed.

Deep Insights into the Developmental Progress of Orally Disintegrating Tablet Formulation, Techniques, and Products: A Comprehensive Review

When it comes to the design of dosage forms, the ease of medication administration and patient compliance are given significant consideration. Recently developed and emerging technologies may be used to make durable, multifunctional tablets that have exceptional flavor masking properties and controlled release. It is possible to consume orally disintegrating tablets (ODTs) without drinking water since they break down in the mouth in less than 60 seconds and dissolve completely in the mouth. Rapid disintegration of the tablet results in rapid dissolving and, as a result, rapid beginning of action. ODts are a suitable dosage form for special populations such as pediatrics, geriatrics, psychotic patients, patients who are unable to swallow properly, bedridden patients, unconscious patients, young patients with a poorly developed muscular and nervous system, patients who have hand tremors, and patients who travel frequently. Good stability, correct dosage, simplicity of manufacture, and reduced packing size are all advantages; self-administration is allowed throughout the trip since water is not necessary. It is also environmentally friendly. ODTs are a cost-effective technique of delivering medications. When medicine is absorbed via the buccal cavity, oral drug delivery systems (ODTs) are very significant. For the production of ODTs, a variety of scientific procedures have been used, including spray drying, sublimation, freeze-drying, molding, and direct compression. Today, ODTs are more readily accessible as over-the-counter medications for the treatment of a broad range of disorders than they were before. The purpose of this article is to discuss the benefits, limits, formulation issues, manufacturing procedures, patented technologies, and commercially available formulations of ODTs in general.

Invariant of Enhanced AES Algorithm Implementations Against Power Analysis Attacks

The security of Internet of Things (IoT) is a challenging task for researchers due to plethora of IoT networks. Side Channel Attacks (SCA) are one of the major concerns. The prime objective of SCA is to acquire the information by observing the power consumption, electromagnetic (EM) field, timing analysis, and acoustics of the device. Later, the attackers perform statistical functions to recover the key. Advanced Encryption Standard (AES) algorithm has proved to be a good security solution for constrained IoT devices. This paper implements a simulation model which is used to modify the AES algorithm using logical masking properties. This invariant of the AES algorithm hides the array of bits during substitution byte transformation of AES. This model is used against SCA and particularly Power Analysis Attacks (PAAs). Simulation model is designed on MATLAB simulator. Results will give better solution by hiding power profiles of the IoT devices against PAAs. In future, the lightweight AES algorithm with false key mechanisms and power reduction techniques such as wave dynamic differential logic (WDDL) will be used to safeguard IoT devices against side channel attacks by using Arduino and field programmable gate array (FPGA).

SENSORY VARIATION ANALYSIS IN ICE CREAM MADE BY PALMYRA (BORASSUS FLABELLIFER) PULP WITH JAGGERY AND SELECTED SPICES

Ice cream is a wholesome, nutritious frozen dairy product. Consumer acceptance of ice cream depends largely on its structure, textural quality, resistance to melting, nutritional composition and flavour. Incorporation of fruits and spices is one of the choices to increase consumer acceptance. The study was focused to develop a nutritional and flavour rich palmyra pulp ice cream with selected spices and jaggery. Eight sensory evaluation tests were carried out with 30 semi-trained panellist using 5 point hedonic scales. Initial sensory evaluation test results reveals pulp which is less bitter and added in overrun combination was selected for both natural and commercial pulp. Then 25% of pulp was selected for both type of pulp. By using the combination which is selected in previous sensory evaluation natural pulp ice cream and commercial pulp ice cream were developed. From that; natural pulp ice cream was preferred as best. Then for the selected ice cream, 125 ppm level of ginger and cinnamon oleoresins incorporated products were selected as best outputs. When comparing cinnamon natural pulp ice cream and ginger natural pulp ice cream, the first one was preferred because of bitterness masking property of ginger. At the end of sensory evaluations, jaggery added ginger flavoured natural palmyra ice cream was developed without adding artificial colouring and preservatives.

SENSORY VARIATION ANALYSIS IN ICE CREAM MADE BY PALMYRA (BORASSUS FLABELLIFER) PULP WITH JAGGERY AND SELECTED SPICES

Ice cream is a wholesome, nutritious frozen dairy product. Consumer acceptance of ice cream depends largely on its structure, textural quality, resistance to melting, nutritional composition and flavour. Incorporation of fruits and spices is one of the choices to increase consumer acceptance. The study was focused to develop a nutritional and flavour rich palmyra pulp ice cream with selected spices and jaggery. Eight sensory evaluation tests were carried out with 30 semi-trained panellist using 5 point hedonic scales. Initial sensory evaluation test results reveals pulp which is less bitter and added in overrun combination was selected for both natural and commercial pulp. Then 25% of pulp was selected for both type of pulp. By using the combination which is selected in previous sensory evaluation natural pulp ice cream and commercial pulp ice cream were developed. From that; natural pulp ice cream was preferred as best. Then for the selected ice cream, 125 ppm level of ginger and cinnamon oleoresins incorporated products were selected as best outputs. When comparing cinnamon natural pulp ice cream and ginger natural pulp ice cream, the first one was preferred because of bitterness masking property of ginger. At the end of sensory evaluations, jaggery added ginger flavoured natural palmyra ice cream was developed without adding artificial colouring and preservatives.

Repellency of Wild Oregano Plant Volatiles, Plectranthus Amboinicus, and Their Essential Oils to the Silverleaf Whitefly, Bemisia Tabaci, on Tomato.

The Bemisia tabaci (Gennadius) whitefly is a major economically damaging pest of many crops such as tomato (Solanum lycopersicum L.). Pesticides are widely used to control B. tabaci while the use of aromatic plants is an alternative control method. The aim of this study was to assess the B.tabaci repellent effect of wild oregano, Plectranthus amboinicus (Lour.) Spreng, a widespread aromatic plant in the West Indies. We tested three origins of wild oregano, including northern, central, and southern Martinique (French West Indies). Our results showed that all essential oils of wild oregano had either masking properties or were true repellents-the mean percentage of whiteflies present in the upper part of the still-air olfactometer was 1.3- to 1.9-fold lower than in the controls. The ethanolic solution of volatile organic compounds of wild oregano from southern Martinique also had a true repellent effect-the mean percentage of whiteflies present in the upper part of the still-air olfactometer was 1.3-fold lower than in the controls. Moreover, in a greenhouse insect-proof cage, there were 1.5 fewer adult whiteflies on tomato intercropped with wild oregano from southern Martinique than on tomato alone after 96 h exposure. Our study generated further insight into the potential of P. amboinicus for B. tabaci biocontrol on tomato crops. Wild oregano extracts were repellent to B. tabaci and could be used as a companion plant to prevent whitefly infestations on tomato crops. However, the B. tabaci behavior depends on the plant origin.

Polycaprolactone and polycaprolactone triol blends to obtain a stable liquid nanotechnological formulation: synthesis, characterization and in vitro – in vivo taste masking evaluation

The use of polymeric blends is a potential strategy to obtain novel nanotechnological formulations aiming at drug delivery systems. Saquinavir, an antiretroviral drug, was chosen as a model drug for the development of new stable liquid formulations with unpleasant taste masking properties. Three formulations containing different polymeric ratios (1:3, 1:1 and 3:1) were prepared and properly characterized by particle size distribution, zeta potential, pH, drug content and encapsulation efficiency measurements. The stability was verified by monitoring the zeta potential, particle size distribution, polydispersity index and drug content by 90 days. The light backscattering analysis was used to early identify possible phenomena of instability in the formulations. The in vitro drug release and saquinavir cytotoxicity were evaluated. The in vitro and in vivo taste masking properties were studied using an electronic tongue and a human sensory panel. All formulations presented nanometric sizes around 200 nm and encapsulation efficiency above 99%. The parameters evaluated for stability remained constant throughout 90 days. The in vitro tests showed a controlled drug release and absence of toxic effects on human T lymphocytes. The electronic tongue experiment showed taste differences for all formulations in comparison to drug solutions, with a more pronounced difference for the formulation with higher polycaprolactone content (3:1). This formulation was chosen for in vivo sensory panel evaluation which results corroborated the electronic tongue experiments. In conclusion, the polymer blend nanoformulation developed herein showed the promising application to incorporate drugs aiming at pharmaceutical taste-masking properties.

Application of Printer Toner As a Versatile Intermediate for Protein Immobilization in Flexible Immunosensing Platforms

Introduction For the last years, low-cost microfluidics and microarrays on polyester substrates have gained applications in a variety of fields, including analytical Po int-of- C are systems. The use of a 2D platforms brings a significant reduction in assay costs, both due to a lower consumption of materials and reagents, as well as a simplicity of manufacturing process in comparison to current approaches [1]. Commercial applicability of immunoassays requires the development of efficient strategies for antibody immobilization in bulk quantities on a wide variety of readily available substrates. Other factors, which influence the usefulness of antibody immobilization approach are scalability, reproducibility and cost-efficiency. Simple, one-step methods such as passive adsorption on hydrophobic surfaces or direct protein immobilization with the use of functionalized silanes are particularly appreciated in fabrication of immunosensing platforms [2]. The use of masking properties of cured toner as an intermediate for passive and covalent immobilization of antibodies on poly(ethylene terephtalate) (PET) seems to be an attractive and still undiscovered path for development of immunoassays on versatile, printable substrates [3]. Fabricatio n of t oner-based platforms for Ab-capturing an d immunosensing Throughout presented research two general approaches for immobilization of antibody and antibody-binding protein (protein A/G) were examined: 1) adsorption on pristine PET@toner foil via hydrophobic interactions, 2) amine-dependent, covalent binding on glycidyloxypropyl tromethoxysilane (GTPMS)- coated surface. Print pattern (at various grayscale levels) was designed in ChemSketch 2.0 and printed on PET surface using HP 100 LaserJet P1006 printer at resolution of 1200 dpi. Pristine PET@toner foils were used for passive adsorption. For GTPMS coating, hydrophilization of toner was performed by a 10-minute treatment with the use of UV/ozone cleaner. Then, 3% GTPMS solution in 50% ethanol was dispensed on freshly-oxidized foil for 30 min. Both multi-purpose substrates characterized by different surface properties were then incubated with rabbit anti-CRP antibody or protein A/G followed by surface blocking. Method To fully characterize the analytical performance in a role of immunosensing platforms, two types of immunoreactions were carried out on prepared 2D Ab/protein arrays. Direct immuno-labelling of rabbit anti-CRP antibody with anti-rabbit IgG-alkaline phosphatase (ALP) conjugate aimed at comparative evaluation of specificity and efficiency of antibody coating. Indirect sandwich immunoassay for C-reactive protein was selected as a model to determine basic working parameters of toner-based immunoassay. Antibody-capturing properties of protein A/G surface were evaluated by determination of monoclonal antibody-ALP conjugate binding capacity. For quantitative analysis, enzymatic reaction was carried out by dispensing p-nitrophenyl phosphate as chromogenic ALP substrate. Results and Conclusions Results of immunolabeling confirmed the usefulness of cured toner as an intermediate for efficient antibody and protein A/G coating via hydrophobicity-driven adsorption. Due to an increase of surface area and a hydrophobicity higher than for pristine PET, the densest layers were observed for fully printed surfaces (100% black level). The differences in the surface properties were also reflected in kinetics of antibody binding. UV/ozone treatment resulted in permanent oxidation and thus hydrophilization of toner surface. The introduction of hydroxyl groups favored reaction with GTPMS. Epoxy-silane coating of oxidized toner enabled a rapid fabrication of protein-reactive surface characterized by a high binding capacity in a single step immobilization. Thanks to good adhesion and thus tight bonding of laser-cut adhesive tape to PET@toner, the microchannel architecture was obtained. It opened up the possibility to carry out immunoassays in microfluidic systems. It was proven that presented methodologies, due to the design and fabrication simplicity, use of commonly available materials and up-scalability, could be successfully applied in immunodiagnostics or flexible microfluidics for Lab-on-a-Foil technology.

Robust Blind Speech Watermarking via FFT-Based Perceptual Vector Norm Modulation With Frame Self-Synchronization

Watermarking is an important measure for protecting proprietary digital multimedia data. This paper presents a novel approach to achieving robust and imperceptible blind speech watermarking on a frame-by-frame basis. The proposed method employs two modules operating in the fast Fourier transform (FFT) domain. The first module is referred to as downward progressive quantization index modulation. It modulates the vector norms drawn from FFT coefficients according to a guideline deduced from human auditory masking properties. The second module is referred to as boundary-constrained iterative adjustment. It provides a smooth transition across frames in the resulting speech waveform. Experiment results confirm the imperceptibility of the proposed modulation scheme in terms of the mean opinion score - listening quality objective (MOS-LQO) based on the perceptual evaluation of speech quality (PESQ) metric. The proposed watermarking method matched and exceeded the performance of five state-of-the-art methods in terms of robustness against common speech processing attacks.

Speech enhancement based on perceptually motivated guided spectrogram filtering

In this paper, a single-channel speech enhancement algorithm is proposed by using guided spectrogram filtering based on masking properties of human auditory system when considering a speech spectrogram as an image. Guided filtering is capable of sharpening details and estimating unwanted textures or background noise from the noisy speech spectrogram. If we consider the noisy spectrogram as a degraded image, we can estimate the spectrogram of the clean speech signal using guided filtering after subtracting noise components. Combined with masking properties of human auditory system, the proposed algorithm adaptively adjusts and reduces the residual noise of the enhanced speech spectrogram according to the corresponding masking threshold. Because the filtering output is a local linear transform of the guidance spectrogram, the local mask window slides can be efficiently implemented via box filter with O(N) computational complexity. Experimental results show that the proposed algorithm can effectively suppress noise in different noisy environments and thus can greatly improve speech quality and speech intelligibility.

Optical properties and masking capacity of flowable giomers.

Background and aimsTo assess the color, translucency and masking properties of novel flowable giomers.MethodsThree flowable giomers were used for the fabrication of 1-mm thick samples (n=126) in three different consistencies (Beautifil flow Plus X F00; Beautifil flow F02; Beautifil flow Plus X F03, Shofu Dental Corporation, Japan) and two shades (VITA Classical shade A2 and A3). The relative spectral reflectance was recorded over white, black, C3 (VITA Classical shade C3 simulating a severe tooth discoloration), and a tested-sample colored background. Lightness (L*), and color coordinates a* and b*, Relative Translucency parameter (RTP00) and masking capacity of C3 background were calculated; differences in color and translucency were compared with thresholds for perceptibility and acceptability (PT and AT). Statistical analyses used significance tests for paired samples.ResultsAll tested materials displayed increased values of L*: for A2 F00=86.16(±0.86), F02=86.39(±0.63), F03=86.40(±0.63); for A3: F00=84.24(±0.58), F02=83.34(±0.3), F03=84.19(±0.4), as well as of RTP: for A2 F00=30.34(±0.88), F02=31.37(±0.94), F03=31.11(±1.15), for A3 F00=29.64(±1.64), F02=30.79(±1.02), F03=30.1(±1.26). For A2 samples, the masking capacity was significantly different for all materials, whilst for A3 there were differences only between F00-F03 and F02-F03.ConclusionsThe tested flowable giomers proved high values of lightness and translucency. The color differences between the materials with the same designation and different consistencies were below the perceptibility threshold in most cases. In addition, the differences in relative translucency parameter ranged between the perceptibility and acceptability thresholds. However, all tested flowable giomers had an unacceptable masking capacity for a dyschromic background.