Fingerprint Area Research Articles

THE INFLUENCE OF COLLAGEN PEPTIDE VARIANTS ON COLLAGEN PEPTIDE-LOADED ALGINATE MICROSPHERE CHARACTERISTICS

Aging is characterized by decreased collagen production. Collagen peptide is a hydrolyzed product of collagen. The topical peptide collagen could act as anti-aging, however, only a small concentration of peptide collagen could penetrate the skin. A microsphere is a micro-spherical particle that could increase the penetration of molecules via a transcellular pathway. This present study aims to optimize the microsphere formation of various collagen peptides as active agents, using alginate as a polymer and CaCl2 as a cross-linker. The microsphere was prepared with collagen peptide (CP), hydrolyzed collagen, CP with molecular weight (MW) < 30 kDa and CP with MW > 30 kDa. The microsphere was then characterized for its size, flowability, topography (SEM), protein-alginate interaction (ATRFTIR and DSC), drug loading, and entrapment efficiency. The molecular size of collagen peptide influences the microsphere characteristic. The higher molecular size of collagen resulted in higher microsphere size. The microsphere of CP with MW < 30 kDa has an average size of 2.25 µm (compared to native collagen with an average size of 5.00 µm). The moisture content of the microsphere is 2.27 to 3.52%. The highest drug loading was observed in the native collagen microsphere (23.85%), while the highest entrapment efficiency was also found in the native collagen microsphere (61.80%). From the SEM analysis, all the microspheres showed a sphere's shape. The fingerprint area of protein and alginate was detected in all formulations. Our study showed that the different size of collagen significantly influences the microsphere characteristics.

Elucidating the influence and mechanism of different phenols on the properties, food quality and function of maize starch

This study discusses interaction differences between three phenols (protocatechuic acid, naringin and tannic acid) and starch helix, investigates influences of phenols at different doses on properties of maize starch, and further determines their effects on quality and function of maize-starchy foods. Simulated results indicate variations of phenolic structure (phenolic hydroxyl group amount, glycoside structure and steric hindrance) and dose induce phenols form different complexes with starch helix. Formation of different starch-phenols complexes alters gelatinization (1.65–5.63 J/g), pasting form, water binding capacity (8.83–12.69 g/g) and particle size distribution of starch. Meanwhile, differences in starch-phenols complexes are reflected in fingerprint area (R1045/1022: 0.920 to 1.047), crystallinity (8.3% to 17.0%), rheology and gel structure of starch. Additionally, phenols change texture and color of cold maize cake, giving them different antioxidant capacity and lower digestibility. Findings are beneficial for understanding interaction between starch and different phenols and their potential application.

Fingerprint image encryption based on chaos and nonlinear dynamic “X” model diffusion

It is analyzed that the important part of the fingerprint image is concentrated in one part of the image, and the gray image is the part with useful information in the whole image. Therefore, this paper combines a new fingerprint image encryption algorithm proposed by combining two new one-dimensional chaotic systems, nonlinear functions, and rules with a dynamic "X" model. We propose two new one-dimensional chaotic systems, one is Sin-Cos chaotic system (SCCS) and the other is Cos-Cos chaotic system (CCCS). Firstly, the fingerprint image is binarized and the contour is extracted to get the area of the fingerprint in the image. Then, for the fingerprint area, a round of encryption is carried out by using nonlinear rules and 24 rules of the dynamic X model. Then the whole image is separated into several parts according to the fingerprint position, read into a sequence at one time, and the whole fingerprint image is scrambled and diffused synchronously by using nonlinear rules and functions. The entropy, NPCR, and UACI of the algorithm are very close to the ideal value, and the performance in time efficiency is passable. The algorithm is extremely secure in a large number of test performance analysis results.

Data fusion of FT-NIR and ATR-FTIR spectra for accurate authentication of geographical indications for Gastrodia elata Blume

Gastrodia elata Blume (G. elata Bl.), with its excellent nutritional and medicinal value from Zhaotong, has been protected by geographical indication (GI). Accurate certification of its origin is a prerequisite to safeguard consumer interests and maintain the market. Four different regions and three varieties of G. elata Bl. from Zhaotong were used in this study (n = 262). Tri-step infrared spectroscopy was used for ATR-FTIR spectral analysis to filter out fingerprint regions for data fusion with FT-NIR spectra, after which conventional discriminant models (PLS-DA and GS-SVM) were built. The second derivative (SD), multiple scattering correction (MSC), and Savitzky-Golay (SG) preprocessing were also performed on the spectra, and it was found that the preprocessing improved the performance of the PLS-DA model. The optimal model results in GS-SVM, based on mid-level data fusion of principal components (PCs) and latent variables (LVs), with sensitivity, specificity, accuracy, and Matthews correlation coefficient (MCC) of 1 for the test set. Furthermore, the residual convolutional neural network (ResNet) models were built, based on FT-NIR full spectra, band 3600−2700 cm−1 (MFA) and band 1750−500 cm−1 (MFB). Their accuracy in both train and test sets exceeds 97%, and the loss function curve is close to 0, which indicates that these three bands can be used as a fingerprint area to verify the GI of Zhaotong G. elata Bl. This study provides a fast, non-invasive method for the authentication of food or medicinal plant GI.

Flavonoid and main aroma-active compounds identification of Taiwan Citrus depressa Hayata’s peels

Citrus peels are a known source of flavonoids and pleasant aroma compounds. Flavonoid compounds in peels of Taiwanese Citrus depressa Hayata (shiikuwasha) were extracted using microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE). Different solvents like distilled water, 50% aqueous ethanol, and methanol were used. The qualitative analysis was carried out by observing UV/Vis and FTIR-ATR spectra, and then quantitatively by High Performance Liquid Chromatography – Diode Array Detector (HPLC-DAD). The composition of volatile aroma components was analyzed using GCHS-SPME (Gas Chromatography, Head Space Solid Phase Microextraction). UV/Vis analysis showed highest intensity at samples that treated by MAE in 50% aqueous ethanol. HPLC DAD quantitatively confirmed UV results by showing that MAE with ethanol showed higher amounts of quercetin, myricetin, rutin, and kaempferol (670.00, 0.36, 8282.52, 7307.51 µg/g), compared to UAE (336.17, 0.20, 5000.62, 4469.15 µg/g), respectively. FTIR-ATR (Fourier-Transform Infrared Spectroscopy - Attenuated total reflectance) showed typical vibrations at phenolic compounds fingerprint area. Unlike quercetin as flavonoid standard, shiikuwasha peels extract showed peak at polymethoxyflavones (PMF) area (2829 – 2835 cm-1 ). Fresh and dried unripe peels mostly contained limonene (53.01 – 54.79%), γ-terpinene (27.67 – 29.41%), pinene, myricene and cymene (1.61 – 3.20%) as aroma-active compounds.

Monocular 3D Fingerprint Reconstruction and Unwarping.

Compared with contact-based fingerprint acquisition techniques, contactless acquisition has the advantages of less skin distortion, more complete fingerprint area, and hygienic acquisition. However, perspective distortion is a challenge in contactless fingerprint recognition, which changes the ridge frequency and relative minutiae location, and thus degrades the recognition accuracy. We propose a learning-based shape-from-texture algorithm to reconstruct a 3-D finger shape from a single image and unwarp the raw image to suppress the perspective distortion. Our experimental results for 3-D reconstruction on contactless fingerprint databases show that the proposed method has high 3-D reconstruction accuracy. Experimental results for contactless-to-contactless and contactless-to-contact-based fingerprint matching indicate that the proposed method can improve the matching accuracy.

Partial Least Squares-Discriminant Analysis Classification for Patchouli Oil Adulteration Detection by Fourier Transform Infrared Spectroscopy in Combination with Chemometrics.

This study aims to test chemometrically partial least squares-discriminant analysis (PLS-DA) classification models to detect the adulteration of patchouli oil (PO) with gurjun balsam oil (GBO) by utilization of Fourier transform infrared spectroscopy. Unsupervised analysis was tested using the pattern recognition method using the principal component analysis model against the original spectrum at wavenumbers 4000-500 cm-1 and at the fingerprint area (1800-600 cm-1). Model testing was also carried out on the spectrum that had been pre-processed using the standard normal variate, second derivative Savitzky-Golay, and normalization approaches. Variable Y samples used were certified reference material (CRM), PO, GBO, and PO forged with GBO (PGBO) with a counterfeiting ratio of 0.5 (v/v) to 10% (v/v) with an interval of 0.5%. The same treatment was carried out on testing of the PLS-DA model. In pattern recognition tests, the best separation of the original spectrum was obtained at wavenumbers 1800-600 cm-1. The model was further tested on PLS-DA by making assumptions or codes for CRM, PO, GBO, and PGBO as +2, +1, 0, and -1, respectively. The results of the model analysis showed that even at the lowest counterfeiting ratio (0.5%), the presence of counterfeiting material was detected by the PLS-DA model. The RMSEC value is close to zero with a value of 0.22, and the R square is close to 1, which is 0.954. This very significant separation is clearly illustrated in the loading plot and bi-plot due to the contribution of chemical compounds in the GBO that undergo vibration at wavenumbers 603, 786, and 1386 cm-1. Validation of the PLS-DA model was carried out strongly using the PLS model, and it showed that the difference between the calibration concentration and the prediction was very low (average 0.45) with an accuracy percent above 99%. The efficacy of the model is further substantiated by the consistent and precise values of sensitivity and selectivity, obtained from both the training set and test set.

Sexual dimorphism and bilateral difference of fingerprint sweat pore among Slovak population

Third level dermatoglyphic markers show a high level of individuality. Despite this fact, the occurrence of individual sweat pore types is still insufficiently studied due to their problematic extraction. The aim of our study was to evaluate the variability of sweat pore types on distal fingertips in the Slovak population and to establish the most uniform method for delineating the evaluated fingerprint area of 1 cm2 in size to avoid bias in the obtained data. In this study, the variability of seven sweat pore types (round, rhomboid, elliptical, square, rectangular, triangular, hexagonal) on distal phalanges were investigated in a sample of 60 volunteers (30 females and 30 males) from the Slovak population. The evaluated area was 1 cm2. Since none of the previously used definition methods seems to be completely reliable, we developed our own method using individual types of dermatoglyphic patterns. This method allowed an uniform location of the studied fingerprint area. The results suggest that sweat pores, like other dermatoglyphic characteristics, have strong identification potential. Several statistically significant bilateral and intersexual differences were found in both male and female populations. Significant intersexual differences in all categories were found in rhomboid and rectangular sweat pore types. Their use could be applied to partial or otherwise unusable fingerprints. The results of this study could help to incorporate these prints into the identification process, allowing their full use.

Fabrication and characterization of fly ash-based geopolymer and its performance for immobilization of heavy metal cations

In this study, the geopolymer from fly ash as based-raw material has been examined on the ability of several heavy metal ions immobilization. The fly ash has been provided from PT IPMOMI which firstly analyzed the physical and chemical properties. Fly ash and heavy metals were mixed with an activator base until homogeneous, then cast into a cylindrical shape mold following ASTM C 39-86 and left for 7 days. After that, the geopolymer was characterized by SEM, FTIR, XRD, compressive strength test and TCLP. The diffractogram of PT. IPMOMI fly ash exhibited the existence of mullite, alumina and iron oxide phase, which were suitable with XRF result. From FTIR spectra, the vibration on finger print area appeared indicating the vibration of T-O-T from geopolymer network. The observation revealed that the addition of Pb2+ cations caused microcracking from SEM image and affected the compressive strength of the geopolymer. Sr2+ was an ion that was very easilyleached compared to other three ions, and it caused a weak interaction between Sr2+ and geopolymer network. The higher amount of metal ions into the geopolymer network reduced the compressive strength of geopolymer. Sr2+-geopolymer had a lower compressive strength compared to Pb2+, Cd2+, and Co2+.

PRODUCTION OF CELLULOSE ACETATE MEMBRANE FROM COCOA (THEOBROMA CACAO L) SHELL MODIFIED POLYETHYLENE GLICOL FOR PB METAL ION FILTRATION

In this study, a modified polyethylene glycol modified cellulose acetate membrane was made. Cellulose acetate was synthesized from cocoa husk waste (Theobroma cacao L) with several steps, namely isolation of alpha cellulose from cocoa husk waste, synthesis of cellulose acetate from alpha cellulose, preparation of 10% cellulose acetate membrane with the addition of polyethylene glycol 0, 5, 10, 15, 20 & 25% . From the results of the research, it was found that the FT-IR analysis of -cellulose from cocoa shells showed an absorption peak at wave numbers between 3400 – 3500 cm-1 which indicated the presence of O-H stretch groups. At wave numbers 2800-2900 cm-1 indicates C-H stretching, then it can be seen at wave numbers 1160 cm-1 indicates C-O-C stretching, and at 1035-1060 cm-1 indicates C-O stretching. In the fingerprint area, we found absorption peaks at wave numbers around 1300 cm-1 which indicated the presence of C-H bending and around 1400 cm-1 indicating the presence of CH2 bending. The cellulose acetate obtained is white and smooth compared to alpha cellulose. At the membrane preparation stage, the results of the insoluble cellulose acetate & PEG using acetone as a solvent. So it is necessary to do a solubility test and find a suitable solvent to form polyethylene glycol modified cellulose acetate membrane for Pb metal ion filtration.

Discrimination of raw and sulfur-fumigated ginseng based on Fourier transform infrared spectroscopy coupled with chemometrics

Ginseng (Panax ginseng), as a tonic and functional food in many countries and regions for thousands of years, is often sulfur-fumigated (SF) for storage and protection. However, our previous study indicated sulfur-fumigation could transform ginsenosides, the active components of ginseng, into sulfur-containing derivatives and thus affect the quality and safety of ginseng. In this study, a rapid and efficient method in discrimination of non-fumigated (NF) and SF ginseng was developed using Fourier transform infrared (FT-IR) spectroscopy coupled with multivariate statistical analysis. A total of 240 batches of raw spectra were obtained from NF and SF ginseng by FT-IR spectroscopy. After excluding the outliers, the different performance of 3 spectral signal enhancing methods, 3 modeling evaluation methods, and 4 model evaluation indexes were compared. The results demonstrated the feasibility of using FT-IR spectroscopy between 3650 and 3200 cm−1 for the detection of sulfur-fumigation in ginseng. After sulfur fumigation, the peak areas in fingerprint and functional group area varied significantly. In addition, the parameters of back propagation artificial neural network (BP-ANN) evaluation model are the highest, its accuracy = 91.67%, precision = 89.29%, recall = 96.15%, and F1 = 92.59%. The error rates of 3 models were k-nearest neighbor algorithm (KNN) (25.00%) > logistic regression (LR) (16.67%) > BP-ANN (8.33%). It can be concluded that FT-IR spectroscopy combined with multivariate statistical analysis has great potential in rapid discrimination of NF and SF ginseng, which can provide a valuable reference for the quality and effectiveness of edible and medicinal application of ginseng.

Investigations on spectroscopic, ADMET properties and drug-likeness, molecular docking, chemical properties of (2E)-3-(biphenyl-4-yl)-1-(2,4-dichlorophenyl)-prop-2-en-1-one by combined density-functional theory

The title compound, (2E)-3-(Biphenyl-4-yl)-1-(2,4-dichlorophenyl)-prop-2-en-1-one (BPDC) has been derived from the compounds namely biphenyl-4-carbaldehyde and 2,4-dichloroacetophenone to perform 3D-Potential energy conformations for molecular stability by DFT calculation of B3LYP/6-311++G(d,p). The geometrical optimization and atoms vibrational spectral data observed FT-IR and FT-Raman spectra values were compared with theoretical values (B3LYP, CAM-B3LYP). The molecule was characterized by absorbed infrared radiation, scattered Raman techniques with the attention on important functional groups (Cl, O, N). Electro negativity difference has been discussed and their biochemical and biomedical properties have been examined. The chemical reactivity of the compound was characterized by MEP-map, NHO, NLMO, and NBO analyses. The frontier molecular orbital (HOMO–LUMO) energy gap, vertical electron truncation of UV–Visible spectrum, and their λ-max value have been compared with CAM-B3LYP and M062X/6-311++G(d,p) approach data. The orbitals arrangements were studied by the density of states (DOS) and the partial density of states (PDOS). BPDC is investigated by Hirshfeld surface analysis that employs three-dimensional contours and two-dimension fingerprint area for intermolecular interactions quantitatively. The biological investigations like drug-likeness and toxicity properties of BPDC molecule were conformed to Lipinski's rule of five and ADMET properties, respectively. The title molecule exhibits a good bioactive score and less toxicity. Antibacterial and also antifungal activities of BPDC were done by docking analysis.

Synthesis, Characterization, and Electrochemical Sensing Applications of Bimetallic Oxide/Carbon Nanomaterials Hybrids

Bimetallic oxide/carbon nanomaterials hybrids were chemically synthesized and fully characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), High-resolution transmission electron microscopy (HRTEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The elemental analysis confirmed the successful formation of MnCo2O4/carbon nanomaterials. The fingerprint area of FTIR showed the incorporation of the metal oxides onto CNTs and GO surfaces. Morphological investigations of the hybrids, using FESEM and HRTEM, revealed the uniform distribution of bimetallic oxides nanostructures over the surface of carbon nanomaterials. Furthermore, electrochemical characteristics were explored using the CV and EIS. The obtained electrochemical results demonstrated significant improvements in the electrocatalytic properties, in addition to the direct and fast electron transfer provided by the modified surfaces whereas the MnCo2O4/CNTs were exploited for the nano-enzymatic amperometric detection of hydrogen peroxide as an example to show the promising applications of such nanomaterials in designing high-efficiency nano-sensors and biosensors.

A New Pt(II) Complex with Anionic s-Triazine Based NNO-Donor Ligand: Synthesis, X-ray Structure, Hirshfeld Analysis and DFT Studies.

The reaction of PtCl2 with s-triazine-type ligand (HTriaz) (1:1) in acetone under heating afforded a new [Pt(Triaz)Cl] complex. Single-crystal X-ray diffraction analysis showed that the ligand (HTriaz) is an NNO tridentate chelate via two N-atoms from the s-triazine and hydrazone moieties and one oxygen from the deprotonated phenolic OH. The coordination environment of the Pt(II) is completed by one Cl−1 ion trans to the Pt-N(hydrazone). Hirshfeld surface analysis showed that the most dominant interactions are the H···H, H···C and O···H intermolecular contacts. These interactions contributed by 60.9, 11.2 and 8.3% from the whole fingerprint area, respectively. Other minor contributions from the Cl···H, C···N, N···H and C···C contacts were also detected. Among these interactions, the most significant contacts are the O···H, H···C and H···H interactions. The amounts of the electron transfer from the ligand groups to Pt(II) metal center were predicted using NBO calculations. Additionally, the electronic spectra were assigned based on the TD-DFT calculations.

Latent Fingerprint Indexing: Robust Representation and Adaptive Candidate List

Efficiently identifying the mated gallery fingerprint of a latent fingerprint in a large database requires a highly accurate and efficient fingerprint matching algorithm. The common strategy to achieve this goal is to combine an efficient indexing algorithm with a slow but accurate matching algorithm. Despite of the importance of latent indexing, it has received far less attention than rolled and plain fingerprint indexing. Due to the small fingerprint area, poor image quality and huge variety in information quantity of latent fingerprints, existing rolled and plain fingerprint indexing approaches cannot be simply migrated to the latent fingerprint indexing. In this paper, we propose (1) a multi-scale fixed-length representation approach for latent fingerprint indexing, and (2) a fingerprint information quantity estimation approach for adaptive candidate list reduction. The representation scheme is designed to deal with small finger area and low image quality of latents. The information quantity of a latent is a predictor of the indexing score of its mated gallery fingerprint and thus can be used to determine a proper threshold for its candidate list. Extensive experimental results on NIST SD27, MOLF, N2N, and Hisign latent fingerprint databases show that the proposed method achieved the state-of-the-art indexing accuracy on latent fingerprints, and significantly improved the efficiency of state-of-the-art latent matching algorithm.

Spectroscopic study of Co-doped CaCu3Ti4O12

Calcium-copper titanate has been thoroughly studied by scientists around the world for several decades due to the manifestation of colossal dielectric permeability values (ε ~104 –105) in wide frequency ranges (102 –106 Hz) and temperature ranges (100 – 600 K), showing neither ferroelectric nor relaxor properties. Due to the unique dielectric characteristics of calcium-copper titanate (CCTO), materials based on it are promising for the manufacture of multilayer capacitors and microwave devices. Restrictions on the practical use of CCTO are caused by high dielectric losses. Electrophysical characteristics are optimized by modifying the CCTO composition, partially replacing copper, titanium and calcium cations. Good dielectric properties are demonstrated by the CCTO ceramics doped with cobalt atoms. Co-doped CaCu3Ti4O12 was obtained by solid phase synthesis method. The samples are characterized by a grain microstructure; a thin layer of CuO is fixed in the intergranular space. From the interpretation of the obtained XPS- and NEXAFS 2p-spectra of Co-doped CaCu3Ti4O12 and the corresponding oxides it can be concluded that in the Co-doped ССТО atoms of copper and calcium have a charge state of +2, atoms of titanium — +(4 − δ), and cobalt atoms mainly +2 with some fraction of Co (III) in the high spin state. The Co-doped sample FTIR spectrum clearly captures the absorption bands in the fingerprint area at ≈408, 488, 539 cm−1, which are typical for ССТО.

Synthesis of 3D Hollow Structured MnCo2O4/CNTs Nanocomposite and Its Magnetic Properties

In the present contribution, the 3D hollow structure of manganese cobalt oxide/carbon nanotubes (MnCo2O4/CNTs) nanocomposite was successfully synthesized through a co-precipitation procedure followed by post-heat treatment. The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Based on the obtained results, the surface of carbon nanotubes was coated uniformly in radial directions by manganese oxide (MnO2) nanosheets forming a flower-shaped structure. In the next step, cobalt oxide precursor was introduced to form MnCo2O4/CNTs nanocomposite. The XRD data confirms the formation of MnCo2O4/CNTs. The estimated values of the strain and the crystallite size based on the Williamson-Hall (W-H) method are calculated as 5.326 × 10−4 and 16 nm respectively. The fingerprint area of FTIR suggests the successful incorporation of MnO2 and cobalt oxide onto CNTs’ surfaces. The flower-shaped structure in the nanoscale is verified by the FESEM and TEM devices. Furthermore, the magnetic specifications revealed the paramagnetic with a small ferromagnetic component of the aforementioned MnCo2O4/CNTs nanocomposite.

In Search of Magnetic Properties of Samarium Cobalt (Sm2Co17) within a Low-Temperature Sintering Process

Samarium cobalt is known as super high density magnetic material with large magnetic anisotropy energy. Samarium–cobalt exhibits manipulative magnetic properties as a rare-earth material which has different properties in a low sintering temperature. It is therefore of paramount importance to investigate samarium cobalt (Sm2Co17) magnetic properties in the low temperature sintering condition. Sm2Co17, which is utilized in this research, is synthesized via the sol–gel process at sintering temperatures of 400, 500, and 600 °C. Subsequently, the crystallites indicate the formation of a single-phase Sm2Co17 on all the samples in all temperature variations. Moreover, the peaks in the X-ray diffraction analysis of crystallite sizes calculated using the Scherrer equation are 17.730, 15.197, and 13.296 nm at 400, 500, and 600 °C. Through scanning electron microscopy, the particles are found to be relatively large and agglomerated, with average sizes of 143.65, 168.78, and 237.26 nm. The functional groups are also analyzed via Fourier-transform infrared spectroscopy, which results in the appearance of several bonds in the samples, for example, alkyl halides, alkanes, and esters with aromatic functional groups on the fingerprint area and alkynes, alkyl halides, and alcohol functional groups at a wavelength of above 1500 cm. The test results of the magnetic properties using vibrating-sample magnetometer (VSM) revealed high coercivity and retentivity in the samples sintered at 400 °C. However, the highest saturation occurs in the samples sintered at 600 ℃. At a low sintering temperature (below 1000 °C), samarium cobalt shows as the soft magnetic material. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Investigation of mango (Mangifera odorate) sap and starch as organic adhesive of bio-briquette

Rice husk and coconut shell waste is potential biomass found in Palembang that has not been utilized properly. Besides being used for primary purposes, biomass can be used for energy sources like renewable energy. Biomass residues can be obtained from the pyrolysis process with thermal cracking units (UTC) and used as bio-briquettes. Bio-briquette is prepared from a mixture of pyrolysis residues of coconut shell and rice husk with a mass ratio of 2:1 using a combination of adhesive mucilage (mango sap) and paste (starch). The adhesive is prepared by dissolving the starch in water, then mixing it into melted mango sap. The mass ratio of the sap and starch is 1:1 (w/w), while the ratio of the mixture of adhesive and water is 1:10. Based on the ATR-FTIR characterization, it showed that the C = C strain group and the C-H bending group appeared at 2800 cm−1, which was confirmed by its appearance at 800 cm−1 in the fingerprint area. Then, appears peak in the area of 1300 cm−1, indicating the presence of a nitro group, which is assumed to have come from mango sap. Measurements of the briquette physicochemical properties such as moisture content, ash content volatile matter, and fixed carbon were measured using the proximate analysis method. Furthermore, the addition of coconut shells in producing bio briquettes from rice husks increased the calorific value by 7.305 MJ kg−1. So that, bio-briquette is an effective as an alternative energy source to replace fossil fuel for household purposes.

Visualizing shed skin cells in fingerprint residue using dark-field microscopy.

This proof-of-concept study shows that dark-field microscopy provides sufficient contrast for cell visualization in fingerprints with high sebum content. Although the application is limited to smooth surfaces that do not scatter light, such as polyethylene terephthalate (PET), it was able to measure the number of cells deposited within a fingerprint residue and the reduction in cell transfer with repeated skin contact. On a PET surface, at roughly 5N of contact force, a typical finger transfers several hundred cells onto the surface. Over subsequent finger contacts onto a clean PET surface, this number decreased exponentially until a steady state was reached, which is characterized by the transfer of (78±36) cells or (0.46±0.21) cells/mm2 when normalized for fingerprint area. High uncertainty in cell transfer was due to: the highly variable nature of a human finger (where the number of loose cells varies from person to person and from day to day depending on what they touch) and difficulties in controlling the contact force and finger movement such as twisting during deposition (where twisting of the finger can expose a new patch of skin to the substrate, increasing the number of cell transfer). Plasma etching was also explored as an effective way to validate dark-field microscopy for cell counting. Although limited to inorganic substrates due to etching effects, exposing the fingerprint for less than 10min can remove a majority of the sebum while keeping the cells intact for a before-and-after comparison using light microscopy.