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1.
PLoS One ; 19(4): e0300929, 2024.
Article in English | MEDLINE | ID: mdl-38635673

ABSTRACT

The expanding urbanization of coastal areas has led to increased ocean sprawl, which has had both physical and chemical adverse effects on marine and coastal ecosystems. To maintain the health and functionality of these ecosystems, it is imperative to develop effective solutions. One such solution involves the use of biodegradable polymers as bioactive coatings to enhance the bioreceptivity of marine and coastal infrastructures. Our study aimed to explore two main objectives: (1) investigate PHA-degrading bacteria on polymer-coated surfaces and in surrounding seawater, and (2) comparing biofilm colonization between surfaces with and without the polymer coating. We applied poly(3-hydroxybutyrate) [P(3HB)) coatings on concrete surfaces at concentrations of 1% and 6% w/v, with varying numbers of coating cycles (1, 3, and 6). Our findings revealed that the addition of P(3HB) indeed promoted accelerated biofilm growth on the coated surfaces, resulting in an occupied area approximately 50% to 100% larger than that observed in the negative control. This indicates a remarkable enhancement, with the biofilm expanding at a rate roughly 1.5 to 2 times faster than the untreated surfaces. We observed noteworthy distinctions in biofilm growth patterns based on varying concentration and number of coating cycles. Interestingly, treatments with low concentration and high coating cycles exhibited comparable biofilm enhancements to those with high concentrations and low coating cycles. Further investigation into the bacterial communities responsible for the degradation of P(3HB) coatings identified mostly common and widespread strains but found no relation between the concentration and coating cycles. Nevertheless, this microbial degradation process was found to be highly efficient, manifesting noticeable effects within a single month. While these initial findings are promising, it's essential to conduct tests under natural conditions to validate the applicability of this approach. Nonetheless, our study represents a novel and bio-based ecological engineering strategy for enhancing the bioreceptivity of marine and coastal structures.


Subject(s)
Ecosystem , Polyhydroxybutyrates , Polymers , 3-Hydroxybutyric Acid/metabolism , Polymers/chemistry , Bacteria/metabolism
2.
Bioresour Technol ; 393: 130054, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37995876

ABSTRACT

Polyhydroxyalkanoates (PHAs) are promising alternatives to non-degradable polymers in various applications. This study explored the use of biologically recovered PHA as a biofilm carrier in a moving bed biofilm reactor for acid orange 7 treatment. The PHA was comprised of 86 ± 1 mol% of 3-hydroxybutyrate and 14 ± 1 mol% of 3-hydroxyhexanoate and was melt-fused at 140 °C into pellets. The net positive surface charge of the PHA biocarrier facilitated attachment of negatively charged activated sludge, promoting biofilm formation. A 236-µm mature biofilm developed after 26 days. The high polysaccharides-to-protein ratio (>1) in the biofilm's extracellular polymeric substances indicated a stable biofilm structure. Four main microbial strains in the biofilm were identified as Leclercia adecarboxylata, Leuconostoc citreum, Bacillus cereus, and Rhodotorula mucilaginosa, all of which exhibited decolourization abilities. In conclusion, PHA holds promise as an effective biocarrier for biofilm development, offering a sustainable alternative in wastewater treatment applications.


Subject(s)
Benzenesulfonates , Polyhydroxyalkanoates , Polyhydroxyalkanoates/chemistry , Sewage/chemistry , Azo Compounds , Biofilms , Bioreactors
3.
RSC Adv ; 13(42): 29332-29341, 2023 Oct 04.
Article in English | MEDLINE | ID: mdl-37818268

ABSTRACT

Iron oxide/carbon-based nanocomposites are known as an ideal combination of magnetic-conductive materials that were recently developed in radar absorption application; one example is the Fe3O4/multiwalled carbon nanotubes (MWCNTs). In this study, we try to boost their radar absorption ability by Mn-ion doping. Mn is an appropriate Fe substitute that is predicted to alter the magnetic properties and enhance the conductivity, which are crucial to developing their radar absorption properties. Diethylamine (DEA) is also used as a capping agent to improve the size and shape of the nanocomposite. In this study, a MnxFe3-xO4-DEA/MWCNT nanocomposite is successfully prepared by the coprecipitation method using a variation of x = 0, 0.25, 0.5, 0.75, and 1. We found that the sample's magnetic saturation (Ms) decreases, while the reflection loss (RL) increases with increasing the molar fraction of Mn. The enhancement of the radar wave absorption in the sample is dominated by dielectric losses due to the increase of electrical conductivity and interfacial polarization with the addition of Mn in the nanocomposites. We believe that our finding could shed light on the role of doping elements to develop the radar absorption properties, and further pave the way for the real implementation of iron oxides/graphene-based nanocomposite as radar-absorbing materials (RAMs).

4.
RSC Adv ; 13(39): 27634-27647, 2023 Sep 08.
Article in English | MEDLINE | ID: mdl-37727586

ABSTRACT

Stealth technology advances in radar-absorbing materials (RAMs) continue to grow rapidly. Barium hexaferrite is the best candidate for RAMs applications. Manganese dioxide (MnO2) is a transition metal with high dielectric loss and can be used as a booster for changing polarization and reducing reflection loss. The advantages of BaFe12O19 and MnO2 can be combined in a core-shell BaFe12O19@MnO2 composite to improve the material's performance. MnO2 composition, temperature, hydrothermal holding time, and sample thickness all have an impact on the core-shell structure. In this study, a core-shell BaFe12O19@MnO2 composite is synthesized in two stages: molten salt synthesis to produce BaFe12O19 as the core and hydrothermal synthesis to synthesize MnO2 as the shell. In the hydrothermal synthesis, BaFe12O19 and KMnO4 were mixed in deionized water using different mass ratios of BaFe12O19 to KMnO4 (1 : 0.25, 1 : 0.5, 1 : 0.75, and 1 : 1). The main goal of the analysis was to figure out how well the hydrothermal synthesis method worked at different temperatures (140 °C, 160 °C, and 180 °C) and holding times (9 h, 12 h, and 15 h). The composite material was subjected to characterization using a vector network analyzer, specifically at thicknesses of 1.5 mm, 2 mm, 2.5 mm, and 3 mm. The hydrothermal temperature and composition ratio of BaFe12O19 : MnO2 are the most influential parameters in reducing reflection loss. Accurate control of the parameters makes a BaFe12O19@MnO2 core-shell composite structure with a lot of sheets. The structure is capable of absorbing 99.99% of electromagnetic waves up to a sample thickness of 1.5 mm. The novelty of this study is its ability to achieve maximal absorptions on a sample with minimal thickness through precise parametric control. This characteristic makes it highly suitable for practical applications, such as performing as an anti-radar coating material. BaFe12O19@MnO2 demonstrates performance as a reliable electromagnetic wave absorber material with simple fabrication, producing absorption at C and X band frequencies.

5.
Heliyon ; 9(5): e16355, 2023 May.
Article in English | MEDLINE | ID: mdl-37305474

ABSTRACT

[This corrects the article DOI: 10.1016/j.heliyon.2021.e06598.].

6.
J Basic Clin Physiol Pharmacol ; 34(4): 539-547, 2023 Jul 01.
Article in English | MEDLINE | ID: mdl-37209011

ABSTRACT

OBJECTIVES: Exercise is one of the beneficial mediators for the regulation and prevention of obesity through the role of irisin, so it potentially enhances metabolism health. This study aims to investigate the dynamic of irisin secrecy change after chronic exercise in obese females. METHODS: Thirty-one female adolescents aged 20-22 years enrolled in the study and were given interventions aerobic, resistance, and a combination of aerobic and resistance training. The exercises were performed at moderate-intensity, for 35-40 min per session, and three times a week for four weeks. The measurement of irisin level, IGF-1 level, and bio-anthropometry was carried out before and after the four weeks of exercise. The bio-anthropometry measurement was carried out using seca mBCA 514, while the measurement of insulin-like growth factor 1 (IGF-1) and irisin was completed using an enzyme-linked immunosorbent assay (ELISA). The obtained data were analyzed using a one-way ANOVA test with 5 % significance. RESULTS: Our results indicated higher dynamic of irisin and IGF-1 increases in the group with a combination of aerobic and resistance training exercises than the other two groups with a different exercise. Further, we also observed different dynamics of irisin and IGF-1 level increase (p<0.05). Besides, the irisin was also correlated with the IGF-1 and bio-anthropometric parameters (p<0.05). CONCLUSIONS: The combination of aerobic and resistance training exercises is considered as the alternative for enhancing the dynamic of irisin and IGF-1 increase. Thus, it can be used to prevent and regulate obesity.


Subject(s)
Fibronectins , Insulin-Like Growth Factor I , Adolescent , Female , Humans , Exercise/physiology , Obesity/prevention & control
7.
Saudi J Biol Sci ; 30(2): 103546, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36624736

ABSTRACT

Obesity is a global metabolic disease anchored by a lack of physical activity lipid disturbances. Hitherto, betatrophin is a potential liver-derived hormone that regulates lipid metabolism. A total of 26 selected onset obese individuals (BMI range ± 28-31) were enrolled in this study and given moderate-intensity exercise. Importantly, our data show that acute moderate-intensity interval exercise (MIIE) and acute moderate-intensity continue to exercise (MICE) for 40 min significantly decrease the plasma level of full-length betatrophin respectively (174.18 ± 48.19 ng/mL; 182.31 ± 52.69 ng/mL), compared to the placebo (283.97 ± 32.23 ng/mL) post 10 min and 6 h exercise treatment (p ≤ 0.05). The plasma level of betatrophin was significantly and negatively correlated with BMI (r = - 0.412, p = 0.037), fasting blood glucose (r = - 0.390, p = 0.049), and positively correlated with VO2max (r = 0.456, p = 0.019). In addition, the linear and ordinal logistic regression analysis shows that betatrophin, is a potential predictor for BMI [estimate value = 0.995, p = 0.037 and OR (95 % CI) = 0.992 (0.0984-1.00), p = 0,048]. In summary, our data demonstrate that the circulating levels of betatrophin were decreased after acute moderate-intensity exercise training.

8.
J Relig Health ; 62(1): 627-649, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36029452

ABSTRACT

This cross-sectional study was conducted on 1139 Muslims in Indonesia. Attitudes and practices were assessed using a questionnaire developed by researchers referring to the main points of the Indonesian Ulema Council fatwa on religious activities during the COVID-19 pandemic. The findings suggest that most participants held positive attitudes (86.5%) and engaged in practices (76.4%). The regression analysis also indicates that attitudes explained approximately 31.5% of the variance in the practice score and 11.2% in the practice score while controlling for gender, age, residence, and education. The study reveals that understanding the relationship between sociodemographic variables, attitudes, and practices is relevant to implementing government policies related to religious practices during the COVID-19 pandemic.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Islam , Indonesia , Cross-Sectional Studies , Pandemics , Attitude , Health Knowledge, Attitudes, Practice
9.
Heliyon ; 8(12): e12218, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36544840

ABSTRACT

The present study was designed to investigate the political interactions of Kiai of Nahdlatul Ulama (NU) in the national political arena and its current impact on the Indonesian Muslim community. The data were garnered through interviews and focus group discussions with Kiai and related parties. The results of the study suggest that the political orientation of the Kiai of NU in Indonesia is oriented to pragmatism and oriented to piety idealism in politics based on Islamic ethics. The Kiai, as a symbol of religious leaders, is expected to lead the Muslim community on a political path that is valuable and morally based. The phenomenon of Kiai interaction in practical politics is a significant leap and break that should be translated into a more comprehensive political perspective on social and historical aspects. The study findings implicate that Kiai as a religious figure, should be put on the front row for Indonesian political discourses among Nahdlatul Ulama followers.

10.
Heliyon ; 8(1): e08695, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35028470

ABSTRACT

BACKGROUND: Diabetes mellitus (DM) is a chronic and costly disease that has become a primary concern worldwide. Type 1 diabetes mellitus is categorized as an autoimmune disease, which results in islet cell apoptosis and insulin-dependent. GAD65 is known as a potential marker of impaired pancreatic ß cell function that appears in the initial phase of type 1 DM and latent autoimmune diabetes in adults (LADA). This study aimed to develop a novel rapid test of anti-GAD65 autoantibodies in human serum samples. METHODS: We have developed a rapid test for anti-GAD65 autoantibodies in this assay based on the reverse-flow immunochromatography method. Human recombinant-protein antigen for GAD65 was attached as the control line over the nitrocellulose membrane. On the other side, the goat anti-mouse immunoglobulin G (IgG) was coated on the same membrane as a control line. The positive result for GAD65 was confirmed by a colloidal gold signal on the strip. Our novel assay analyzed 276 healthy subjects and 51 type 1 diabetes individuals serum samples from several ethnicities in Indonesia for this study. RESULTS: Among the 276 healthy samples, 225 samples were identified as positive for anti-GAD65 autoantibodies, while 51 samples were negative. Interestingly, the positive results for anti-GAD65 autoantibodies were linear to the decreasing of high-density lipoprotein (HDL) levels and inversely associated with triglyceride levels. A significant correlation with age was observed in all groups. The sensitivity and specificity test proved that this kit has higher accuracy (AUC value = 0.960). CONCLUSION: The significant advantages of our rapid test for anti-GAD65 autoantibodies provide higher sensitivity, specificity, and stability compared to previous commercial kits. Therefore, it could be proposed as the future clinical diagnostic kit for patient management of type 1 DM.

11.
An Acad Bras Cienc ; 93(4): e20200774, 2021.
Article in English | MEDLINE | ID: mdl-34705939

ABSTRACT

This study performs natural sand-based synthesis using the sonochemical route for preparing Zn-doped magnetite nanoparticles. The nanoparticles were dispersed in water as a carrier liquid to form Zn-doped magnetite aqueous ferrofluids. Structural data analysis indicated that the Zn-doped magnetite nanoparticles formed a nanosized spinel structure. With an increase in the Zn content, the lattice parameters of the Zn-doped magnetite nanoparticles tended to increase because Zn2+ has a larger ionic radius than those of Fe3+ and Fe2+. The existence of Zn-O and Fe-O functional groups in tetrahedral and octahedral sites were observed in the wavenumber range of 400-700 cm-1. The primary particles of the Zn-doped magnetite ferrofluids tended to construct chain-like structures with fractal dimensions of 1.2-1.9. The gas-like compression (GMC) plays as a better model than the Langevin theory to fit the saturation magnetization of the ferrofluids. The ferrofluids exhibited a superparamagnetic character, with their magnetization was contributed by aggregation. The Zn-doped magnetite ferrofluids exhibited excellent antibacterial activity against gram-positive and negative bacteria. It is suggested that the presence of the negatively charged surface and the nanoparticle size may contribute to the high antibacterial activity of Zn-doped magnetite ferrofluids and making them potentially suitable for advanced biomedical.


Subject(s)
Ferrosoferric Oxide , Sand , Anti-Bacterial Agents/pharmacology , Magnetic Phenomena , Water , Zinc
12.
Heliyon ; 7(4): e06598, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33937538

ABSTRACT

This study was conducted to investigate the odontogenic proliferation and differentiation of dental pulp stem cells (DPSCs) after induction by nanoparticle mineral trioxide (NMT). DPSCs were isolated from permanent teeth and placed in tubes containing Dulbecco's modified Eagle's medium, followed by immunocytochemistry analysis. The viability of DPSCs exposed to NMT was measured using MTT assay with trypan blue dye exclusion. Alkaline phosphatase (ALP) activity was evaluated using ALP colorimetric reactions by reacting NMT supernatants with fluorescent-specific ALP substrates. The concentration of osteocalcin was determined using an instant human osteocalcin enzyme-linked immunosorbent assay (ELISA) kit. A human dentin sialophosphoprotein (DSPP) ELISA kit coated with anti-human DSPP antibody was employed to measure DSPP levels. There was a significant difference between ALP activity after exposing the cells to NMT and trioxide mineral aggregate on days 3, 7, and 21. Osteocalcin activity showed a significant difference on days 3, 7, 14, and 21. There was a significant difference in DSPP levels on days 7 and 21. DPSCs exposed to NMT and to trioxide mineral aggregate showed extracellular matrix formation on day 7 and 14, respectively. Furthermore, NMT may effectively increase the proliferation and differentiation of DPSCs as well as their maturation toward odontoblasts.

13.
Heliyon ; 7(3): e06549, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33851049

ABSTRACT

The purpose of this study was to investigate the leadership practices of Indonesian Islamic boarding school (pesantren) leaders, school principals, and teachers in responding to the health crisis caused by the COVID-19 pandemic, to ensure the continuation of boarding school education in the "new normal" period. Generated using a moderated focus group discussion with principals and teachers, the findings suggest that principals' and teachers' leadership practices are acceptable in the policy, social support, and financial dimensions but still lack structural and teaching aspects about conducting blended learning. Based on this study's findings, pesantren leaders (kyai) and school principals should pay attention to training programs for implementing blended learning for teachers. The government is encouraged to assist in providing technical facilities pesantren can implement blended learning more effectively.

14.
Heliyon ; 6(7): e04577, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32760844

ABSTRACT

Mn1-x Zn x Fe2O4 ferrofluids were produced from natural sand for magnetic sensors and radar absorbing materials. The X-ray diffraction data showed that the Zn partially substituted the Mn and Fe ions to construct a spinel structure. The increasing Zn composition decreased the lattice parameters of the structure. The transmission electron microscopy images showed that the filler Mn1-x Zn x Fe2O4 nanoparticles tended to agglomerate in three dimensions. Lognormal and mass fractal models were used to fit the small-angle X-ray scattering data of the ferrofluids demonstrated that the ferrofluids formed chain-like structures with a fractal dimension of 1.12-1.67 that was constructed from primary particles with sizes of 3.6-4.1 nm. The filler, surfactant, and carrier liquid of the ferrofluids were confirmed by the functional groups of the metal oxides, tetramethylammonium hydroxide, and H2O, respectively. The secondary particles contributed to the saturation magnetization of the Mn1-x Zn x Fe2O4 ferrofluids. The Mn1-x Zn x Fe2O4 ferrofluids demonstrated excellent performance as magnetic sensors with high stability, especially compared with MnFe2O4 ferrofluids. Furthermore, the ferrofluids exhibited excellent radar absorbing materials. The Mn1-x Zn x Fe2O4 ferrofluids prepared in this work may serve as a future platform for advancing magnetic sensors and radar absorbing materials.

15.
J King Saud Univ Sci ; 32(7): 3032-3038, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32837112

ABSTRACT

The preparation of Co-doped magnetite ferrofluids from natural sand was developed using a double-layer technique. The Co-doped magnetite nanoparticles formed a spinel phase with lattice parameters in the range of 8.355-8.422 Å and tended to agglomerate with the particle sizes of 7-12 nm. The presence of the first and second layers from oleic acid and DMSO was detected by the infrared spectrum as well as the olive oil used as a carrier liquid. The saturation magnetization of the superparamagnetic samples decreased from 24.4 to 4.8 emu/g with decreasing Co2+ composition. The particle size and electrostatic forces between the magnetic particles and the microbes played an essential role in inhibiting microbial growth. Interestingly, the increasing Co2+ composition enhanced the superior performance of the ferrofluids against E. coli, S. aureus, B. subtilis, and C. albicans. With additional extensive investigation, we believe that the prepared Co-doped magnetite double-layered ferrofluids from natural sand with superior antimicrobial performance can be new significant antimicrobial agents.

16.
Heliyon ; 6(4): e03784, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32322741

ABSTRACT

In this study, we report the synthesis of the magnetite/silica nanocomposites and their structural and functional groups, magnetic properties, morphology, antimicrobial activity, and drug delivery performance. The X-ray diffraction characterization showed that magnetite formed a spinel phase and that silica formed an amorphous phase. The particle sizes of magnetite increased from 8.2 to 13.2 nm with increasing silica content, and the particles were observed to be superparamagnetic. The nanocomposites tended to agglomerate based on the scanning electron microscopy images. The antimicrobial activity of the magnetite/silica nanocomposites revealed that the increasing silica content increased the inhibition zones by 74%, 77%, and 143% in case of Gram-positive bacteria (B. subtilis), Gram-negative bacteria (E. coli), and fungus (C. albicans), respectively. Furthermore, doxorubicin was used as the model compound in the drug loading and release study, and drug loading was directly proportional to the silica content. Thus, the increasing silica content increased the drug loading owing to the increasing number of OH- bonds in silica, resulting in strong bonds with doxorubicin. Based on this study, the magnetite/silica nanocomposites could be applied as drug delivery vehicles.

17.
Heliyon ; 6(12): e05813, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33426329

ABSTRACT

To date, the search for creating stable ferrofluids with excellent properties for biomedical application is one of the challenging scientific and practical investigations. In this study, novel Fe3O4/Ag nanohybrid ferrofluids from iron sand were synthesized using a double-layer method. The Fe3O4/Ag nanocomposites exhibited stable crystallite sizes of 11.8 12.1 nm and 36.8-37.2 nm for Fe3O4 and Ag, respectively. The lattice parameters of the spinel structure Fe3O4 and face-centered cubic Ag were respectively 8.344 Å and 4.091 Å. With increasing Ag amount, the crystallite phase of Ag in the nanocomposites increased from 40.2% to 77.2%. The XPS results confirmed that Fe3O4/Ag nanocomposites were successfully prepared, where Fe3O4 mixed well with Ag via strong ionic bonding. The FTIR results confirmed the presence of Fe3O4/Ag, oleic acid, and dimethyl sulfoxide as the filler, first layer, and second layer, respectively. The as-prepared ferrofluids exhibited superparamagnetic behavior, where the saturation magnetization decreased with increasing Ag content. The Fe3O4/Ag nanohybrid ferrofluids exhibited excellent antimicrobial performance against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Candida albicans. More importantly, the Fe3O4/Ag nanohybrid ferrofluids decreased the progression of liver fibrosis-related inflammation and fibrogenic activity on hepatic stellate cells.

18.
Water Res ; 148: 292-305, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30390510

ABSTRACT

Number of populations, industry, and economic activities in Indonesia are growing rapidly and these impacts on natural environments raise awareness about water quality issue over the country. Bandung Basin, one of the most growing rapidity urban areas in Indonesia, was assessed for NO3- contamination in groundwater systems, and its controlling factors and driving mechanisms were investigated with the aim to demonstrate novelty on the use of combination of parameters of stable isotope ratios in nitrate (δ15N and δ18O in NO3-), groundwater age (using CFC-12 age tracer), and socioeconomic parameters (land-use, population, and economic database). Groundwater NO3- concentrations at present time did not exceed HWO limit for all the analyzed samples (3.00 mg/L in average with maximum value of 20.69 mg/L, n = 102). Dual stable isotopic analysis together with CFC-12 groundwater age determination suggest that anthropogenic activities are the major causes for increasing NO3- concentrations in groundwater. Those activities under respective land-use are industrial and domestic wastes for urban areas and chemical fertilizers for paddy and plantations areas. In general shallow unconfined aquifer is more vulnerable to NO3- contamination compared with deep confined aquifer because denitrification partly occurs in deep anoxic aquifer and this led attenuation of NO3- pollution in groundwater flowing. However, it seems likely at groundwater depression cones in urban areas that more concentrated waters are transported from shallow aquifer into deep aquifer system through downward vertical fluxes due to excessive pumping. Principal component analysis (PCA) on NO3- concentrations with socioeconomic parameters indicated that industrial and population growths are the main factors related to groundwater NO3- contamination. This result corresponds to CFC-age dating which shows younger (more recently recharged) groundwaters as being more contaminated than older ones do. Our study implies that NO3- contamination in this area may become more severe in future with a lack of necessary controls and treatment for human-induced nitrogen sources. Proposed approach is useful to understand how the NO3- contaminant behaves in large basin aquifer system under urban environments and might be applicable in other developing regions too because increasing populations may be associated with increasing nitrogen loadings.


Subject(s)
Groundwater , Water Pollutants, Chemical , Environmental Monitoring , Humans , Indonesia , Isotopes , Nitrates , Socioeconomic Factors
19.
Scanning ; 2018: 6545803, 2018.
Article in English | MEDLINE | ID: mdl-30524643

ABSTRACT

We report on the effect of the morphological modification on optical properties and polarization of ZnO nanorods (NR). Here, the morphology and structure of the ZnO NR were modified by introducing different annealing temperatures. The increase of length and diameter and change in density of the ZnO NR were clearly observed by increasing the annealing temperature. We found that the samples show different oxygen vacancy (VO) and zinc interstitial (ZnI) concentrations. We suggest that the different concentrations of VO and ZnI are originated from morphological and structural modification. Our results reveal that optical absorption and polarization of ZnO NR could be enhanced by producing a high concentration of VO and ZnI. The modification of VO and ZnI promotes a decrease in the band gap and coexistence of high optical absorption and polarization in our ZnO NR. Our findings would give a broad insight into the morphological modification and characterization technique on ZnO NR. The high optical and polarization characteristics of ZnO NR are potential for developing the high-performance nanogenerator device for multitype energy harvesting.

20.
Springerplus ; 2(1): 137, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23724365

ABSTRACT

Logging and forest loss continues to be a major problem within Southeast Asia and as a result, many species are becoming threatened or extinct. The present study provides the first detailed and comprehensive ecological data on the Siberut macaque (Macaca siberu), a primate species living exclusively on the island of Siberut off the west coast of Sumatra. Our results show that M. siberu is ecologically similar to its closest relative M. nemestrina occurring on the mainland, both species being semi-terrestrial, mainly frugivorous (75-76%), exhibit a large daily travel distance for their group size and spend more time on traveling than any other macaque species. The habitat of Siberut macaques was floristically very diverse (Simpson's index D=0.97), although somewhat impoverished in tree species richness, and had a lower tree basal area and a lower rattan density compared to other forests in Malesia (both rattan and palm tree fruit being an important food resource for Macaca siberu due to their long fruiting periods). These factors may lead to a lower diversity and abundance of fruit resources, and coupled with a high degree of frugivory of Siberut macaques, may explain the large amount of traveling observed in this species. The large home range requirements and strong dependence on fruit are important factors that need to be considered when developing conservation measures for this IUCN-listed (Category Vulnerable) species.

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