Human systemic exposure to [¹⁴C]-paraphenylenediamine-containing oxidative hair dyes: Absorption, kinetics, metabolism, excretion and safety assessment.

Science.gov (United States)

Nohynek, Gerhard J; Skare, Julie A; Meuling, Wim J A; Wehmeyer, Kenneth R; de Bie, Albertus Th H J; Vaes, Wouter H J; Dufour, Eric K; Fautz, Rolf; Steiling, Winfried; Bramante, Mario; Toutain, Herve

2015-07-01

Systemic exposure was measured in humans after hair dyeing with oxidative hair dyes containing 2.0% (A) or 1.0% (B) [(14)C]-p-phenylenediamine (PPD). Hair was dyed, rinsed, dried, clipped and shaved; blood and urine samples were collected for 48 hours after application. [(14)C] was measured in all materials, rinsing water, hair, plasma, urine and skin strips. Plasma and urine were also analysed by HLPC/MS/MS for PPD and its metabolites (B). Total mean recovery of radioactivity was 94.30% (A) or 96.21% (B). Mean plasma Cmax values were 132.6 or 97.4 ng [(14)C]-PPDeq/mL, mean AUC(0-∞) values 1415 or 966 ng [(14)C]-PPDeq/mL*hr in studies A or B, respectively. Urinary excretion of [(14)C] mainly occurred within 24 hrs after hair colouring with a total excretion of 0.72 or 0.88% of applied radioactivity in studies A or B, respectively. Only N,N'-diacetylated-PPD was detected in plasma and the urine. A TK-based human safety assessment estimated margins of safety of 23.3- or 65-fold relative to respective plasma AUC or Cmax values in rats at the NOAEL of a toxicity study. Overall, hair dyes containing PPD are unlikely to pose a health risk since they are used intermittently and systemic exposure is limited to the detoxified metabolite N,N'-diacetyl-PPD. Copyright © 2015 Elsevier Ltd. All rights reserved.

A STUDY ON CONTACT DERMATITIS TO HAIR DYE AND HENNA

Directory of Open Access Journals (Sweden)

Neerja Puri

2013-10-01

Full Text Available P- Phenylenediamine is an oxidative chemical that is frequently used as a permanent hair-coloring agent. It is added to henna to increase the intensity and longevity of the tattoo and expedites its drying time. Henna itself is a greenish brown vegetable coloring made from the leaves of Lawsonia inermis and rarely causes allergic contact dermatitis. The addition of PPD causes the contact sensitization to black henna. Serious adverse skin reactions to permanent hair dyes and temporary black tattoos have been reported. As temporary tattoos have become fashionable among adolescents, the risk profile for p-phenylenediamine (PPD sensitization of the population has changed simultaneously with an increasing use of hair dyes in this age group. With increased popularity of body art such as body piercing and tattooing, an increase in temporary henna tattoos has also occurred. Although the appeal of non-permanence exists for henna tattoos, dermatologists have begun to see numerous cases of allergic contact dermatitis linked with a certain type of henna. We selected 50 patients using hair dye and henna for our study. Patch testing was done in all the patients using Indian standard series of antigens. Regarding to the side effects to hair dye and henna and itching was the commonest symptom seen in 16% patients, erythematous scaly plaques were seen in 10% patients, vesicular reactions were seen in 6% patients, angioneurotic oedema and contact urticaria was seen in 4% patients each and anaphylaxis and keloidal reaction was seen in 2% patients each.

Ranking of hair dye substances according to predicted sensitization potency

DEFF Research Database (Denmark)

Søsted, H; Basketter, D A; Estrada, E

2004-01-01

Allergic contact dermatitis following the use of hair dyes is well known. Many chemicals are used in hair dyes and it is unlikely that all cases of hair dye allergy can be diagnosed by means of patch testing with p-phenylenediamine (PPD). The objectives of this study are to identify all hair dye...... in order to help select a number of chemically diverse hair dye substances that could be used in subsequent clinical work. Various information sources, including the Inventory of Cosmetics Ingredients, new regulations on cosmetics, data on total use and ChemId (the Chemical Search Input website provided...... by the National Library of Medicine), were used in order to identify the names and structures of the hair dyes. A QSAR model, developed with the help of experimental local lymph node assay data and topological sub-structural molecular descriptors (TOPS-MODE), was used in order to predict the likely sensitization...

Severe allergic hair dye reactions in 8 children

DEFF Research Database (Denmark)

Sosted, Heidi; Johansen, Jeanne Duus; Andersen, Klaus Ejner

2006-01-01

Serious adverse skin reactions to permanent hair dyes and temporary black tattoos have been reported. As temporary tattoos have become fashionable among adolescents, the risk profile for p-phenylenediamine (PPD) sensitization of the population has changed simultaneously with an increasing use...... of hair dyes in this age group. This investigation reports PPD sensitization in children with regard to cause of sensitization, clinical presentation and consequences. Clinical history and patch test results for consecutive children below 16 years of age with suspected hair dye allergic reactions...... and positive patch tests to PPD were collected over 2 years in 2 Danish dermatology clinics. 8 children aged 12-15 years were collected, and they all reacted to several hair dye ingredients. 5 of the patients were hospitalized, 1 in the intensive care unit. 6 of the patients gave a history of prior reaction...

Personal use of hair dyes and temporary black tattoos in Copenhagen hairdressers

DEFF Research Database (Denmark)

Hansen, Henriette S; Johansen, Jeanne D; Thyssen, Jacob P

2010-01-01

Hairdressers are occupationally and personally exposed to hair dye substances and adverse reactions from the skin are well known. Currently, little is known about personal exposure to hair dye ingredients and temporary black tattoos.......Hairdressers are occupationally and personally exposed to hair dye substances and adverse reactions from the skin are well known. Currently, little is known about personal exposure to hair dye ingredients and temporary black tattoos....

Comparative sensitizing potencies of fragrances, preservatives, and hair dyes

DEFF Research Database (Denmark)

Lidén, Carola; Yazar, Kerem; Johansen, Jeanne Duus

2016-01-01

the sensitizing potencies of fragrance substances, preservatives, and hair dye substances, which are skin sensitizers that frequently come into contact with the skin of consumers and workers, LLNA results and EC3 values for 72 fragrance substances, 25 preservatives and 107 hair dye substances were obtained from...... two published compilations of LLNA data and opinions by the Scientific Committee on Consumer Safety and its predecessors. The median EC3 values of fragrances (n = 61), preservatives (n = 19) and hair dyes (n = 59) were 5.9%, 0.9%, and 1.3%, respectively. The majority of sensitizing preservatives...... and hair dyes are thus strong or extreme sensitizers (EC3 value of ≤2%), and fragrances are mostly moderate sensitizers. Although fragrances are typically moderate sensitizers, they are among the most frequent causes of contact allergy. This indicates that factors other than potency need to be addressed...

Detection of oxidative hair treatment using fluorescence microscopy.

Science.gov (United States)

Witt, Silvana; Wunder, Cora; Paulke, Alexander; Verhoff, Marcel A; Schubert-Zsilavecz, Manfred; Toennes, Stefan W

2016-08-01

In assessing abstinence from drug or alcohol abuse, hair analysis plays an important role. Cosmetic hair treatment influences the content of deposited drugs which is not always detectable during analysis. Since oxidation of melanin leads to an increase in fluorescence, a microscopic method was developed to distinguish natural from cosmetically treated hair. For validation, natural hair samples were treated with different types of cosmetics and inspected by fluorescence microscopy. Hair samples from 20 volunteers with documented cosmetic treatment and as a proof of concept 100 hair samples from forensic cases were analyzed by this method. Apart from autofluorescence with excitation at 365 nm, no obvious fluorescence was observed in untreated hair samples. Tinting and a natural plant product had no influence on fluorescence, but dyeing procedures including oxidation led to a marked increase in fluorescence. Proof of cosmetic treatment was achieved in hair samples from the 20 volunteers. In 100 forensic cases, 13 samples were characterized as oxidatively treated, which was in accordance with the respective disclosure except for one case where treatment was not admitted. This fluorescence microscopic procedure proved to be fast, easy, and reliable to identify oxidatively treated hair samples, which must be considered especially in evaluating cases of negative drug results. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Hair Dyes and Cancer Risk

Science.gov (United States)

... http://www.fda.gov/aboutfda/centersoffices/officeoffoods/cfsan/default.htm . Selected References Huncharek M, Kupelnick B. Personal use of hair dyes and the risk of bladder cancer: results of a meta-analysis. ...

55 cases of allergic reactions to hair dye: a descriptive, consumer complaint-based study

DEFF Research Database (Denmark)

Søsted, H; Agner, T; Andersen, Klaus Ejner

2002-01-01

themselves, and adverse reactions to hair dye may not necessarily be recorded by the health care system, unless the reactions are especially severe. Based on this assumption, we suspected that hair dye dermatitis was occurring more frequently than reported in the literature. Consumer complaint-based data......Severe facial and scalp dermatitis following the use of permanent hair dyes has been reported in several cases. Para-phenylenediamine (PPD) is known as a potent contact allergen, and PPD is allowed in hair dye at a concentration of 6%. Hair dye reactions are usually diagnosed by the patients...

A study of knowledge, attitude and practices regarding hair dye use among general population

Directory of Open Access Journals (Sweden)

Mrinal Gupta

2018-02-01

Full Text Available Background: Hair dye usage is extremely common all over the world. Hair dyes have been reported to cause a wide range of adverse effects, therefore, the consumer’s knowledge about hair dyeing and related side effects are important. Aim: To assess the knowledge, attitude and practices of general population towards the use of hair dyes. Materials and Methods: Two hundred and fifty consecutive persons using hair dyes were enrolled for this questionnaire-based cross-sectional, descriptive study. Results: These 250 patients comprised 141 men (56.4% and 109 women (43.6% (M: F 1.29:1, aged between 16 and 74 (mean 47.13 years. The majority, 212 patients (84.8% were aged between 20–60 years and 66.4% (n=166 belonged to an urban background. When asked about the reason for using hair color, the principle reason was “to look younger” (59.6%, n=149. Most of the respondents were using synthetic hair dye preparations (55.2%, n=138 and when asked about the brand of hair dye being used, 25.2% (n=63 did not know about the brand they were using. When asked about their perception regarding safety of HD, 61% (n=152 respondents agreed that hair dyes are not safe and on being asked about the carcinogenic potential of HD, only 24% (n=60 respondents agreed. When enquired about the safest variety of HD, majority of respondents (52.4%, n=131 believed that plant based hair colors are the safest. When asked about the safety of HD during pregnancy and lactation, 68% (n=168 of the respondents were unaware regarding this aspect. 14.4% of the respondents reported suffering from some adverse effects due to hair dye use but only 11.11% (n=4 of those stopped using hair dyes. Conclusions: There is lack of awareness about the hair dyes and their adverse effects in the general population. There is an urgent need to increase awareness among consumers regarding the adverse effects of hair dyes and the available safer alternatives. Limitations: Small number of respondents and

Contact dermatitis to hair dyes in a Danish adult population: an interview-based study

DEFF Research Database (Denmark)

Søsted, H; Hesse, U; Menné, T

2005-01-01

BACKGROUND: Contact allergy to hair dye ingredients is a well-known entity seen both in consumers using hair dyes and among hairdressers with occupational contact dermatitis. Surveys show that consumers with even severe adverse skin reactions to hair dyes only rarely contact the healthcare services....... The frequency of hair dye-induced skin reactions in the consumer population is unknown. OBJECTIVES: An epidemiological investigation with the aim of establishing the proportion of hair dye-induced skin reactions was performed in a population-based sample. METHODS: A representative random sample (n = 4000......) was taken of the Danish adult population. Personal interview questions were asked regarding adverse skin reactions to hair dyes, either compatible with a classical allergic eczematous reaction with redness, scaling and itching or a severe allergic reaction with oedema of the forehead and face. The response...

21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.18 Coal tar hair dyes... coal tar hair dye containing any ingredient listed in paragraph (b) of this section shall bear, in...

Repeated exposure to hair dye induces regulatory T cells in mice

DEFF Research Database (Denmark)

Rubin, I M C; Dabelsteen, S; Nielsen, M M

2010-01-01

We have recently shown that commercial p-phenylenediamine (PPD)-containing hair dyes are potent immune activators that lead to severe contact hypersensitivity in an animal model. However, only a minority of people exposed to permanent hair dyes develops symptomatic contact hypersensitivity...

Hair dye dermatitis and p-phenylenediamine contact sensitivity: A preliminary report

Directory of Open Access Journals (Sweden)

Mrinal Gupta

2015-01-01

Full Text Available Background: The contact allergic reactions from p-phenylenediamine (PPD in hair dyes vary from mild contact dermatitis to severe life- threatening events (angioedema, bronchospasm, asthma, renal impairment. Objectives: To study the clinical patterns and PPD contact sensitivity in patients with hair-dye dermatitis. Materials and Methods: Eighty (M: F 47:33 consecutive patients aged between 18 and 74 years suspected to have contact allergy from hair dye were studied by patch testing with Indian Standard Series including p-phenylenediamine (PPD, 1.0% pet. Results: 54 Fifty-four (M: F 21:33 patients showed positive patch tests from PPD. Eight of these patients also showed positive patch test reaction from fragrance mix, thiuram mix, paraben mix, or colophony. Fifty-seven (71% patients affected were aged older than 40 years. The duration of dermatitis varied from 1 year with exacerbation following hair coloring. Forty-nine patients had dermatitis of scalp and/or scalp margins and 23 patients had face and neck dermatitis. Periorbital dermatitis, chronic actinic dermatitis, and erythema multiforme-like lesions were seen in 4, 2, and 1 patients, respectively. Conclusions: Hair dyes and PPD constitute a significant cause of contact dermatitis. There is an urgent need for creating consumer awareness regarding hair-dyes contact sensitivity and the significance of performing sensitivity testing prior to actual use.

Morbidity and Mortality in 7,684 Women According to Personal Hair Dye Use

DEFF Research Database (Denmark)

Vedel-Krogh, Signe; Nielsen, Sune F; Schnohr, Peter

2016-01-01

BACKGROUND: Permanent hair dye contains aromatic amines which are carcinogenic, and can cause allergic skin reactions. In the long term personal use of hair dye might therefore influence both morbidity and mortality. OBJECTIVES: We tested the hypothesis that personal use of hair dye in women...... is associated with increased morbidity and mortality in the general population. METHODS: We included 7,684 women from the Copenhagen City Heart Study with information on the use of personal hair dye. We assessed the risk of cancer, skin diseases, other morbidities, and mortality during a median follow-up of 27...... years (range 0-37). RESULTS: The multivariable adjusted hazard ratio for malignant melanoma in women with versus without personal use of hair dye was 2.07 (95% confidence interval 1.25-3.42). There was no increased risk of other cancer types. For other skin diseases and other major causes of morbidity...

Continuous usage of a hair dye product containing 2-methoxymethyt-para-phenylenediamine by hair-dye-allergic individuals

NARCIS (Netherlands)

Kock, M.; Coenraads, P. -J.; Bloemeke, B.; Goebel, C.

Background Despite a positive patch test reaction to para-phenylenediamine (PPD) and/or toluene-2,5-diamine (PTD), many people attempt to continue dyeing their hair with products containing PPD or its derivatives. Objectives Investigation of elicitation reactions among PPD/PTD-allergic individuals

Protection of oxidative hair color fading from shampoo washing by hydrophobically modified cationic polymers.

Science.gov (United States)

Zhou, Y; Foltis, L; Moore, D J; Rigoletto, R

2009-01-01

The fading of oxidative color in hair as a result of daily shampoo washing activities has become a common problem and a source of frequent complaints by consumers. The fading occurs primarily through hair dye solubility in water. One aspect of the current study investigates the physical and chemical factors that influence hair color fading during the washing process. This is accomplished by testing hair dye dissolution in water from dyed hair samples with variation of surfactant type, pH, and hair type. Furthermore, a new approach to preventing color fading is developed aiming to provide an effective barrier function for hair dye from dissolving into water. The preliminary investigation of a series of polymers with various functional groups indicates that polymers with hydrophobically modified and cationic functionalities are most effective in preventing hair dye dissolution in water. It is also evident that a synergistic effect of the polymer's hydrophobic moieties and cationic charges are important on hair color protection during shampoo washing processes. A primary example of a polymer within this category is a cationic terpolymer of vinylpyrrolidone, dimethylaminopropyl methacrylamide, and methacryloylaminopropyl lauryldimonium chloride (INCI: Polyquaternium-55). The color protection benefit of this polymer is evaluated using newly developed methodologies for evaluating hair color changes, such as hair color fading tests through multiple shampoo washes with mannequin heads and hair tresses, both derived from human hair, colorimetry, and quantitative digital image analysis. In addition, new infrared spectroscopic imaging techniques are used to detect the hair dye deposition behavior inside hair fibers both with and without the color protection treatment. Both visual and instrumental measurement results indicate that Polyquaternium-55 provides a high level of color protection when formulated in a hair color protection regimen with up to 50% color protection. This

Personal use of hair dyes and temporary black tattoos in Copenhagen hairdressers.

Science.gov (United States)

Hansen, Henriette S; Johansen, Jeanne D; Thyssen, Jacob P; Linneberg, Allan; Søsted, Heidi

2010-06-01

Hairdressers are occupationally and personally exposed to hair dye substances and adverse reactions from the skin are well known. Currently, little is known about personal exposure to hair dye ingredients and temporary black tattoos. To investigate hairdressers' professional and personal risk exposures and to compare the frequency of temporary tattoos among hairdressers and subjects from the general population. A questionnaire was sent to 1679 Copenhagen hairdressers and 1063 (63.3%) responded; 3471 subjects from the general population in Copenhagen were asked about temporary black tattoos. Of the female hairdressers, 38.3% had coloured hair within the previous week. Adverse skin reactions to own hair dye were reported in 29.5%. In the hairdresser population, no significant association was observed between self-reported adverse skin reactions to hair dye and having had a temporary black tattoo when adjusted for sex, age, and atopy. A total of 19.0% of hairdressers (43.5% of apprentices) and 6.3% of participants from the general population had ever had a temporary black tattoo performed at one point. There were no differences in frequency of eczema after temporary tattooing between hairdressers and subjects in the general population. Almost all hairdressers (99.2%) used gloves for hair colouring, 51% for high/low lighting, 39.6% for perming and 21.1% used gloves for shampooing. In conclusion, skin reactions to hair colour are frequent among Copenhagen hairdressers. Temporary black tattoos were more frequent among hairdressers than in a sample of the general population and increased with decreasing age.

21 CFR 70.20 - Packaging requirements for straight colors (other than hair dyes).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Packaging requirements for straight colors (other than hair dyes). 70.20 Section 70.20 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... straight colors (other than hair dyes). Straight colors shall be packaged in containers which prevent...

PTCA (1H-pyrrole-2,3,5-tricarboxylic acid) as a marker for oxidative hair treatment.

Science.gov (United States)

Petzel-Witt, Silvana; Meier, Sylvia I; Schubert-Zsilavecz, Manfred; Toennes, Stefan W

2018-04-01

Hair analysis for the assessment of alcohol or drug abstinence has become a routine procedure in forensic toxicology. Hair coloration leading to loss of incorporated xenobiotics and to false negative results has turned out to be a major problem. Currently only colored extracts provide hints of manipulations but not bleaching. A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed and validated to determine 1H-pyrrole-2,3,5-tricarboxylic acid (PTCA), a major oxidation product of melanin. PTCA was determined in natural hair samples (n = 21) after treatment with 3% hydrogen peroxide (H 2 O 2 ) for 30 or 40 minutes with concentrations up to 12% for 40 minutes. In another series, 12 natural hair samples were submitted to different coloration procedures (henna, tinting, semi-permanent and permanent dyeing, bleaching) and the changes in PTCA content were determined. A significant increase in the PTCA content was found for both incubation times and increasing H 2 O 2 concentrations. Coloration with henna or tinting had no influence on PTCA levels detected, but a significant increase was observed after semi-permanent and permanent dyeing and bleaching. As PTCA concentrations in natural hair were found to be in a range of <2.1-16.4 ng/mg (8.4 ± 3.8 ng/mg, mean ± SD, n = 33), a cut-off of 20 ng/mg is recommended for the distinction between natural vs. excessively oxidized hair. In case of naturally low melanin content (light-blond or white hair), no marked increase in PTCA may occur. The present study demonstrated that PTCA is formed during oxidative treatment of melanin in hair, which can be used to detect previous hair coloration including oxidation. Copyright © 2017 John Wiley & Sons, Ltd.

Hair Dye–DNA Interaction: Plausible Cause of Mutation

Directory of Open Access Journals (Sweden)

Swati Maiti

2015-09-01

Full Text Available Hair dye is one of the most popular cosmetic products which are used more widely and frequently to improve an individual’s appearance. Although the genotoxic effects of dye ingredients are widely reported, hair dye in its usable form is not reported extensively. In this contribution, we report the possible mode of interaction of hair dye with DNA which leads to genotoxicity. The effect of dye DNA interaction was studied on the most popular and globally used hair dye with Calf Thymus DNA and plasmid DNA. This interaction of dye DNA was studied by spectroscopic analyses and gel electrophoresis. The result had shown positive interaction of dye with DNA. Gel electrophoresis study confirms the binding of dye with DNA which results in linearization and fragmentation of the plasmid DNA. Dye–DNA interaction causes fragmentation and oxidation of DNA in absence of any catalyst, implies high toxicity of commercial hair dyes. Thus, it can be deduced from the present studies that hair dye in its usable form may lead to its penetration through skin affecting genomic DNA possesses genotoxic property and can be treated as one of the most common mutagen.

Self-testing for contact sensitization to hair dyes--scientific considerations and clinical concerns of an industry-led screening programme

DEFF Research Database (Denmark)

Thyssen, Jacob P; Søsted, Heidi; Uter, Wolfgang

2012-01-01

The cosmetic industry producing hair dyes has, for many years, recommended that their consumers perform 'a hair dye allergy self-test' or similar prior to hair dyeing, to identify individuals who are likely to react upon subsequent hair dyeing. This review offers important information...... on the requirements for correct validation of screening tests, and concludes that, in its present form, the hair dye self-test has severe limitations: (i) it is not a screening test but a diagnostic test; (ii) it has not been validated according to basic criteria defined by scientists; (iii) it has been evaluated...... in the wrong population group; (iv) skin reactions have been read by dermatologists and not by the targeted group (consumers and hairdressers); (v) hair dyes contain strong and extreme sensitizers that are left on the skin in high concentrations, potentially resulting in active sensitization; and (vi...

Are gloves sufficiently protective when hairdressers are exposed to permanent hair dyes? An in vivo study.

Science.gov (United States)

Antelmi, Annarita; Young, Ewa; Svedman, Cecilia; Zimerson, Erik; Engfeldt, Malin; Foti, Caterina; Bruze, Magnus

2015-04-01

The use of permanent hair dyes exposes hairdressers to contact allergens such as p-phenylenediamine (PPD), and the preventive measures are insufficient. To perform an in vivo test to study the protective effect of gloves commonly used by hairdressers. Six gloves from Sweden, Italy and Germany were studied: two vinyl, one natural rubber latex, two nitrile, and one polyethylene. The hair dye used for the provocation was a dark shade permanent dye containing PPD. The dye was mixed with hydrogen peroxide, and 8 PPD-sensitized volunteers were tested with the gloves as a membrane between the hair dye and the skin in a cylindrical open chamber system. Three exposure times (15, 30 and 60 min) were used. Eczematous reactions were found when natural rubber latex, polyethylene and vinyl gloves were tested with the dye. The nitrile gloves gave good protection, even after 60 min of exposure to the hair dye. Many protective gloves used by hairdressers are unsuitable for protection against the risk of elicitation of allergic contact dermatitis caused by PPD. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Preparation of demipermanent and semipermanent hair dyes gels from ethanol extract of Caesalpinia sappan L. using carbomer as gelling agent

Science.gov (United States)

Indrawati, T.; Syahrin, A.; Irpan

2017-07-01

Caesalpinia sappan L. (Cs L) contains of essential oils, saponin, brazilin, brazilein, alkaloids, flavonoids and tannins that have a function as cationic natural dyes. The aim of this research was to prepare the ethanol extract of Cs L wood and to prepare demi-permanent and semi-permanent of hair dye gels by using Carbomer of 2 % and 1.5 % as gelling agent and Cs L extract as cationic dyes. The Extract of Cs L was macerated by using ethanol of 96 % as the solvent, and then thickened. Three formula of demi-permanent hair dye gels were made by using Cs L extract of 3 %, 6% and 9 %. Three formula of semi-permanent hair dye gels were made by using Cs L extract of 2.50 %, 7.00 % and 10.50 %. Those hair dyes gels were prepared by swelling and mixing methods. All products of hair dyes gels were evaluated with organoleptic test, homogeneity test, pH test, consistency test, rheological properties test and dyeing effect test. The demi-permanent hair dye gels products had brown to brown dark black colors, pH of 5.05-5.43, homogeny, specific Cs L odor, and had pseudoplastic thixotropic flow characteristic. The semi-permanent hair dye gels products had red color pH of 6.5-6.25, homogeny, Cs L odor, and have pseudoplastic thixotropic flow characteristics. The optimum formula of demi-permanent was formula gel that contained of 6 % extract of Cs L and the optimum formula of permanent hair dyes gel was formula that contained of 10.50 % extract of Cs L.

Skin sensitization quantitative risk assessment for occupational exposure of hairdressers to hair dye ingredients.

Science.gov (United States)

Goebel, Carsten; Diepgen, Thomas L; Blömeke, Brunhilde; Gaspari, Anthony A; Schnuch, Axel; Fuchs, Anne; Schlotmann, Kordula; Krasteva, Maya; Kimber, Ian

2018-06-01

Occupational exposure of hairdressers to hair dyes has been associated with the development of allergic contact dermatitis (ACD) involving the hands. p-Phenylenediamine (PPD) and toluene-2,5-diamine (PTD) have been implicated as important occupational contact allergens. To conduct a quantitative risk assessment for the induction of contact sensitization to hair dyes in hairdressers, available data from hand rinsing studies following typical occupational exposure conditions to PPD, PTD and resorcinol were assessed. By accounting for wet work, uneven exposure and inter-individual variability for professionals, daily hand exposure concentrations were derived. Secondly, daily hand exposure was compared with the sensitization induction potency of the individual hair dye defined as the No Expected Sensitization Induction Levels (NESIL). For PPD and PTD hairdresser hand exposure levels were 2.7 and 5.9 fold below the individual NESIL. In contrast, hand exposure to resorcinol was 50 fold below the NESIL. Correspondingly, the risk assessment for PPD and PTD indicates that contact sensitization may occur, when skin protection and skin care are not rigorously applied. We conclude that awareness of health risks associated with occupational exposure to hair dyes, and of the importance of adequate protective measures, should be emphasized more fully during hairdresser education and training. Copyright © 2018 Elsevier Inc. All rights reserved.

p-Phenylenediamine and other allergens in hair dye products in the United States

DEFF Research Database (Denmark)

Hamann, Dathan; Yazar, Kerem; Hamann, Carsten R

2014-01-01

product contained six (range 0-11). p-Phenylenediamine (PPD) was found in 83 products (78%), but resorcinol (89%), m-aminophenol (75%), p-aminophenol (60%) and toluene-2,5-diamine (21%) were also frequently identified. CONCLUSIONS: Potent contact sensitizers were almost universally included in the hair...... dyes investigated in the United States. Although PPD is a common allergen, resorcinol and m-aminophenol were found more frequently. In total, 30 potent sensitizers were found. Clinicians should consider other allergens in addition to PPD when evaluating patients with suspected hair dye allergy....

Hair cosmetics

Directory of Open Access Journals (Sweden)

Nina Madnani

2013-01-01

Full Text Available The hair cosmetic industry has undergone a revolutionary change over the last two decades. The focus has dramatically veered from merely cleaning to repair, increasing the tensile strength, reducing oxidative damage, and stimulating growth. Newer shorter procedures to make hair look naturally more lustrous, smooth, and manageable have evolved. Specialized grooming products have been formulated to cleanse, calm, and condition the hair, and are tailored for different hair-types, for example, dry, dry-damaged, oily, colored, and gray hair. Other products are formulated to alter the color or structure of the hair shaft, for example, hair dyes, perming/relaxing. Hair sprays and waxes/gels, can alter the ′lift′ of the hair-shaft. Although dermatologists are experts in managing scalp and hair diseases, the esthetic applications of newer cosmetic therapies still remain elusive. This article attempts to fill the lacunae in our knowledge of hair cosmetics and esthetic procedures relevant in today′s rapidly changing beauty-enhancing industry, with special emphasis on the Indian scenario for chemical and ′natural′ hair products.

Enhancing and inhibiting effects of aromatic compounds on luminol-dimethylsulfoxide-OH(-) chemiluminescence and determination of intermediates in oxidative hair dyes by HPLC with chemiluminescence detection.

Science.gov (United States)

Zhou, Jian; Xu, Hong; Wan, Guo-Hui; Duan, Chun-Feng; Cui, Hua

2004-10-08

The effect of 36 aromatic compounds on the luminol-dimethylsulfoxide-OH(-) chemiluminescence (CL) was systematically studied. It was found that dihydroxybenzenes, and ortho- and para-substituted aminophenols and phenylenediamines inhibited the CL and phenols with three or more than three hydroxyls except phloroglucin tended to enhance the CL. The CL inhibition and enhancement was proposed to be dependent on whether superoxide anion radical (O(2)(-)) was competitively consumed by compounds in the CL system. Trihydroxybenzenes were capable of generating superoxide anion radical, leading to the CL enhancement, whereas dihydroxybenzenes were superoxide anion radical scavenger, causing the CL inhibition. Based on the inhibited CL, a novel method for the simultaneous determination of p-phenylenediamine, o-phenylenediamine, p-aminophenol, o-aminophenol, resorcinol and hydroquinone by high-performance liquid chromatography coupled with chemiluminescence detection was developed. The method has been successfully applied to determine intermediates in oxidative hair dyes and wastewater of shampooing after hair dyed.

Hair Dyes Resorcinol and Lawsone Reduce Production of Melanin in Melanoma Cells by Tyrosinase Activity Inhibition and Decreasing Tyrosinase and Microphthalmia-Associated Transcription Factor (MITF Expression

Directory of Open Access Journals (Sweden)

Shu-Mei Lee

2015-01-01

Full Text Available Hair coloring products are one of the most important cosmetics for modern people; there are three major types of hair dyes, including the temporary, semi-permanent and permanent hair dyes. The selected hair dyes (such as ammonium persulfate, sodium persulfate, resorcinol and lawsone are the important components for hair coloring products. Therefore, we analyzed the effects of these compounds on melanogenesis in B16-F10 melanoma cells. The results proved that hair dyes resorcinol and lawsone can reduce the production of melanin. The results also confirmed that resorcinol and lawsone inhibit mushroom and cellular tyrosinase activities in vitro. Resorcinol and lawsone can also downregulate the protein levels of tyrosinase and microphthalmia-associated transcription factor (MITF in B16-F10 cells. Thus, we suggest that frequent use of hair dyes may have the risk of reducing natural melanin production in hair follicles. Moreover, resorcinol and lawsone may also be used as hypopigmenting agents to food, agricultural and cosmetic industry in the future.

Oxidative stress in ageing of hair.

Science.gov (United States)

Trüeb, Ralph M

2009-01-01

Experimental evidence supports the hypothesis that oxidative stress plays a major role in the ageing process. Reactive oxygen species are generated by a multitude of endogenous and environmental challenges. Reactive oxygen species or free radicals are highly reactive molecules that can directly damage cellular structural membranes, lipids, proteins, and DNA. The body possesses endogenous defence mechanisms, such as antioxidative enzymes and non-enzymatic antioxidative molecules, protecting it from free radicals by reducing and neutralizing them. With age, the production of free radicals increases, while the endogenous defence mechanisms decrease. This imbalance leads to the progressive damage of cellular structures, presumably resulting in the ageing phenotype. Ageing of hair manifests as decrease of melanocyte function or graying, and decrease in hair production or alopecia. There is circumstantial evidence that oxidative stress may be a pivotal mechanism contributing to hair graying and hair loss. New insights into the role and prevention of oxidative stress could open new strategies for intervention and reversal of the hair graying process and age-dependent alopecia.

Hair dye-incorporated poly-γ-glutamic acid/glycol chitosan nanoparticles based on ion-complex formation

Directory of Open Access Journals (Sweden)

Lee HY

2011-11-01

Full Text Available Hye-Young Lee1,*, Young-IL Jeong2,*, Ki-Choon Choi31Anyang Science University, Anyang, Gyeonggi, South Korea; 2Chonnam National University Hwasun Hospital, Jeonnam, South Korea; 3Grassland and Forages Research Center, National Institute of Animal Science, Rural Development Administration, Chungnam, South Korea*These authors contributed equally to this work.Background: p-Phenylenediamine (PDA or its related chemicals are used more extensively than oxidative hair dyes. However, permanent hair dyes such as PDA are known to have potent contact allergy reactions in humans, and severe allergic reactions are problematic.Methods: PDA-incorporated nanoparticles were prepared based on ion-complex formation between the cationic groups of PDA and the anionic groups of poly(γ-glutamic acid (PGA. To reinforce PDA/PGA ion complexes, glycol chitosan (GC was added. PDA-incorporated nanoparticles were characterized using field-emission scanning electron microscopy, Fourier-transform infrared (FT-IR spectroscopy, dynamic light scattering, and powder X-ray diffractometry (XRD.Results: Nanoparticles were formed by ion-complex formation between the amine groups of PDA and the carboxyl groups of PGA. PDA-incorporated nanoparticles are small in size (<100 nm, and morphological observations showed spherical shapes. FT-IR spectra results showed that the carboxylic acid peak of PGA decreased with increasing PDA content, indicating that the ion complexes were formed between the carboxyl groups of PGA and the amine groups of PDA. Furthermore, the intrinsic peak of the carboxyl groups of PGA was also decreased by the addition of GC. Intrinsic crystalline peaks of PDA were observed by XRD. This crystalline peak of PDA was completely nonexistent when nanoparticles were formed by ion complex between PDA, PGA, and GC, indicating that PDA was complexed with PGA and no free drug existed in the formulation. During the drug-release experiment, an initial burst release of PDA was

Protein loss in human hair from combination straightening and coloring treatments.

Science.gov (United States)

França-Stefoni, Simone Aparecida; Dario, Michelli Ferrera; Sá-Dias, Tânia Cristina; Bedin, Valcinir; de Almeida, Adriano José; Baby, André Rolim; Velasco, Maria Valéria R

2015-09-01

Hair chemical treatments, such as dyeing and straightening products, are known to cause damage that can be assessed by protein loss. The aim of this study was to evaluate the hair protein loss caused by combined chemical treatments (dye and relaxer) using the validated bicinchoninic acid (BCA) method. Three kinds of straighteners, based on ammonium thioglycolate, guanidine hydroxide and sodium hydroxide, were evaluated and the least harmful combination indicated. Caucasian virgin dark brown hair tresses were treated with developed natural brown color oxidative hair dyeing and/or straightening commercial products based on ammonium thioglycolate, sodium hydroxide, or guanidine hydroxide. Protein loss quantification was assessed by the validated BCA method which has several advantages for quantifying protein loss in chemically treated hair. When both treatments (straightening and dyeing) were combined, a higher negative effect was observed, particularly for dyed hair treated with sodium hydroxide. In this case, a 356% increase in protein loss relative to virgin hair was observed and 208% in relation to only dyed hair. The combination of dying and relaxers based on ammonium thioglycolate or guanidine hydroxide caused a small increase in protein loss, suggesting that these straightening products could be the best alternatives for individuals wishing to combine both treatments. These results indicated that when application of both types of products is desired, ammonium thioglycolate or guanidine hydroxide should be chosen for the straightening process. © 2015 Wiley Periodicals, Inc.

Distribution kinetics of 3H-labelled p-phenylene diamine - - a hair dye

International Nuclear Information System (INIS)

Rehani, M.M.; Jain, I.S.; Sharma, S.K.

1981-01-01

The distribution kinetics of the 3 H-labelled p-phenylene diamine (a hair dye compound), was studied when administered iv and when applied percutaneously. The tracer experiments in rabbits after iv administration showed a biphasic blood clearance with half life values of 24 min and 43.5 h and quick-percutaneous absorption. The tissue distribution pattern investigated after iv and percutaneous administration in 16 different tissues and also in blood did not demonstrate any target organ for selective localisation of the dye. Not more than 0.06 percent of the iv administered radioactivity was measured per 10 mg of any tissue at 12th day. (author)

Tryptophan and kynurenine determination in human hair by liquid chromatography.

Science.gov (United States)

Dario, Michelli F; Freire, Thamires Batello; Pinto, Claudinéia Aparecida Sales de Oliveira; Prado, María Segunda Aurora; Baby, André R; Velasco, Maria Valéria R

2017-10-15

Tryptophan, an amino acid found in hair proteinaceous structure is used as a marker of hair photodegradation. Also, protein loss caused by several chemical/physical treatments can be inferred by tryptophan quantification. Kynurenine is a photo-oxidation product of tryptophan, expected to be detected when hair is exposed mainly to UVB (290-320nm) radiation range. Tryptophan from hair is usually quantified directly as a solid or after alkaline hydrolysis, spectrofluorimetrically. However, these types of measure are not sufficiently specific and present several interfering substances. Thus, this work aimed to propose a quantification method for both tryptophan and kynurenine in hair samples, after alkali hydrolysis process, by using high-performance liquid chromatography (HPLC) with fluorimetric and UV detection. The tryptophan and kynurenine quantification method was developed and validated. Black, white, bleached and dyed (blond and auburn) hair tresses were used in this study. Tryptophan and kynurenine were separated within ∼9min by HPLC. Both black and white virgin hair samples presented similar concentrations of tryptophan, while bleaching caused a reduction in the tryptophan content as well as dyeing process. Unexpectedly, UV/vis radiation did not promote significantly the conversion of tryptophan into its photo-oxidation product and consequently, kynurenine was not detected. Thus, this works presented an acceptable method for quantification of tryptophan and its photooxidation metabolite kynurenine in hair samples. Also, the results indicated that bleaching and dyeing processes promoted protein/amino acids loss but tryptophan is not extensively degraded in human hair by solar radiation. Copyright © 2017 Elsevier B.V. All rights reserved.

Hair-dye induced erythema multiforme like allergic contact dermatitis

Directory of Open Access Journals (Sweden)

Mrinal Gupta

2017-04-01

Full Text Available Erythema multiforme (EM is an acute, self limited skin disease characterized by the sudden eruption of symmetrical lesions in typical targetoid fashion usually confined to face and extremities. The most commonly implicated factors include infections like herpes simplex, mycoplasma, drugs like antibiotics and anticonvulsants and vaccinations. Contact dermatitis induced EM is a rarely reported entity. Herein we present a case of a 40 year old female who presented with EM due to contact sensitivity to p-Paraphenylenediamine (PPD, a common coloring agent in hair-dyes and a potent sensitizer. Till date, there have been only a few case reports of PPD induced EM.

Photo- and chemocatalytic oxidation of dyes in water.

Science.gov (United States)

Du, Wei-Ning; Chen, Shyi-Tien

2018-01-15

Three commonly used dyes, Acid Red-114 (AR-114), Reactive Black-5 (RB-5), and Disperse Black EX-SF (DB-EX-SF), were treated in a pH-neutral liquid with ultraviolet (UV) light by two reactive methods: photocatalysis with titanium dioxide (TiO 2 ), and/or chemocatalysis with hydrogen peroxide (H 2 O 2 ) as the oxidant and various ferrous-based electron mediators as catalysts. Important factors for dye oxidation were determined through bifactorial experiments. The optimum combinations and doses of the three key reagents, namely TiO 2 , H 2 O 2 , and EDTA-Fe, were also determined. The degradation kinetics of the studied dyes at their optimum doses reveal that the oxidation reactions are pseudo-first-order in nature, and that certain dyes are selectively degraded more by one method than the other. The overall results suggest that co-treatment using more than one oxidative method is beneficial for the treatment of wastewater from dyeing processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

The oxidation of acid azo dye AY 36 by a manganese oxide containing mine waste

International Nuclear Information System (INIS)

Clarke, Catherine E.; Kielar, Filip; Johnson, Karen L.

2013-01-01

Highlights: ► This study looks at the oxidative breakdown of the amine containing dye acid yellow 36 by a Mn oxide containing mine waste. ► The oxidation proceeds by successive one electron transfers between the dye molecule and the Mn oxide minerals. ► The initial decolorization of the dye is rapid, but does not involve the cleavage of the azo bond. -- Abstract: The oxidative breakdown of acid azo dye acid yellow 36 (AY 36) by a Mn oxide containing mine tailings is demonstrated. The oxidation reaction is pH dependent with the rate of decolorization increasing with decreasing pH. The oxidation reaction mechanism is initiated at the amino moiety and proceeds via successive, one electron transfers from the dye to the Mn oxide minerals. The reaction pathway involves the formation of a number of colorless intermediate products, some of which hydrolyze in a Mn oxide-independent step. Decolorization of the dye is rapid and is observed before the cleavage of the azo-bond, which is a slower process. The terminal oxidation products were observed to be p-benzoquinone and 3-hydroxybenzenesulfonate. The reaction order of the initial decolorization was determined to be pseudo fractional order with respect to pH and pseudo first order with respect to dye concentration and Mn tailings’ surface area

Hemolytic anemia after ingestion of the natural hair dye Lawsonia inermis (henna) in a dog.

Science.gov (United States)

Jardes, Daniel J; Ross, Linda A; Markovich, Jessica E

2013-01-01

To describe the clinical presentation and case management of a dog that developed hemolytic anemia and evidence of renal tubular dysfunction after ingestion of a natural hair dye containing Lawsonia inermis (henna). To review cases of henna toxicity reported in the human literature. An 8-year-old female spayed Border Collie was presented 5 days after ingestion of a box of natural hair dye. The dog was showing signs of lethargy, vomiting, diarrhea, and weakness. A serum biochemistry profile, complete blood count, and urinalysis demonstrated evidence of renal tubular dysfunction and a regenerative anemia without spherocytosis. The dog was treated with a transfusion of packed RBCs and IV fluids, resulting in significant clinical improvement. Repeat diagnostics showed resolution of the anemia and no lasting evidence of tubular dysfunction. To the authors' knowledge, this is the first reported case in the veterinary literature of toxicity following ingestion of Lawsonia inermis (henna). Henna ingestion was associated with the development of hemolytic anemia and acute kidney injury. © Veterinary Emergency and Critical Care Society 2013.

Permeation of hair dye ingredients, p-phenylenediamine and aminophenol isomers, through protective gloves.

Science.gov (United States)

Lee, Hsiao-Shu; Lin, Yu-Wen

2009-04-01

Skin irritation and contact allergies are skin disorders common to hairdressers. The predominant oxidative hair dye components, such as p-phenylenediamine (PPD) and aminophenol isomers, can cause contact dermatitis. Use of protective gloves can prevent dermal contact with skin irritants. This study investigates the permeation behaviors of p-aminophenol (PAP), m-aminophenol (MAP), o-aminophenol (OAP) and PPD in single and mixed challenge solutions with disposable natural rubber latex (NRL) gloves, disposable polyvinylchloride (PVC) gloves and neoprene (NP) gloves. The challenge solutions were 4% PPD (w/v), 3% OAP (w/v), 2% PAP (w/v) and 2% MAP (w/v) in ethanol or 12% hydrogen peroxide solutions. The cocktail solutions of the four chemicals were also tested. An American Society for Testing and Materials type permeation cell, ethanol liquid collection and gas chromatography-flame ionization detection of samples taken from the collection medium every 10 min facilitated determination of breakthrough times (BTs), cumulative permeated masses and steady-state permeation rates (SSPRs). Experiments were 4 h long for the NRL and PVC gloves and 8 h for NP gloves. No chemicals tested broke through the NP gloves when exposed for 8 h. In the ethanol solution, PPD and OAP started breaking through the PVC gloves at 40 min. The SSPRs of PVC gloves were higher than those for NRL gloves in all challenge conditions for both single chemicals and mixtures. No tested chemicals in hydrogen peroxide solutions permeated the gloves during the 4-h tests. The chemical composition of the challenge solution was a main effecter of BTs and SSPRs for the NRL glove. For disposable PVC gloves, the main factors of BTs were molecular size [molar volume (MV)] and polarity (logK(ow)), and the primary factors of SSPRs were concentration, MV and logK(ow). In conclusion, disposable NRL gloves and disposable PVC gloves should not be used repeatedly for handling the hair dye products. Hydrogen peroxide did not

Cross-elicitation responses to 2-methoxymethyl-p-phenylenediamine under hair dye use conditions in p-phenylenediamine-allergic individuals

NARCIS (Netherlands)

Bloemeke, B.; Pot, L. M.; Coenraads, P. -J.; Hennen, J.; Kock, M.; Goebel, C.

Background The factors influencing elicitation responses in individuals allergic to p-phenylenediamine (PPD) in hair dyes are not well understood. Objectives Investigation of the elicitation response to the new, less-sensitizing PPD alternative 2-methoxymethyl-p-phenylenediamine (ME-PPD) under

Sensitization and Clinically Relevant Allergy to Hair Dyes and Clothes from Black Henna Tattoos: Do People Know the Risk? An Uncommon Serious Case and a Review of the Literature

Directory of Open Access Journals (Sweden)

Paola A. Moro

2016-07-01

Full Text Available Henna (Lawsonia inermis L. tattooing has been used in Egypt and India since ancient times. Today this temporary body art is becoming increasingly popular among young people. Various chemicals are added to henna to darken and enhance the definition of tattoos, especially para-phenylenediamine (PPD, which is a strong sensitizer known to cause cross sensitive reactions to azoic dyes and other para-amino compounds. We present the case of an 18-year-old girl who became clinically sensitive to textile dyes after having showed a serious reaction both to her first hair dying when she was 16 years old and following the application of a temporary henna tattoo when she was a kid. The evidence from our literature review showed 33 cases of manifest sensitization to hair dye and only one of observable contact allergy to both hair and textile dyes from henna tattoos. The sensitization of children may have long-life lasting consequences, because of cross-reaction to dyes and other chemicals contained in hair colourants, clothes and drugs. Since tattoos are very popular and globalization has increased the circulation of unauthorized products we point out the need for informative campaigns about the risk of sensitization caused by temporary tattoos.

Self-testing for contact allergy to hair dyes - a 5-year follow-up multicentre study

DEFF Research Database (Denmark)

Friis, Ulrik F; Goosens, An; Giménez-Arnau, Ana Maria

2018-01-01

the method of application, the amount of hair dye applied, the location and size of the application area, the number of applications, whether or not rinsing was performed after application, the reading times, and how a positive reaction was defined. CONCLUSIONS: Self-testing is still recommended by almost...

In liquid laser treated graphene oxide for dye removal

Energy Technology Data Exchange (ETDEWEB)

Russo, Paola, E-mail: rsspla1@gmail.com [Dipartimento di Scienze Chimiche, Universita’ degli Studi di Catania, Viale Andrea Doria 6, Catania 95125 (Italy); Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave., West Waterloo, Ontario N2L 3G1 (Canada); D’Urso, Luisa [Dipartimento di Scienze Chimiche, Universita’ degli Studi di Catania, Viale Andrea Doria 6, Catania 95125 (Italy); Hu, Anming [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, TN 57996-2210 (United States); Zhou, Norman [Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave., West Waterloo, Ontario N2L 3G1 (Canada); Compagnini, Giuseppe [Dipartimento di Scienze Chimiche, Universita’ degli Studi di Catania, Viale Andrea Doria 6, Catania 95125 (Italy)

2015-09-01

Highlights: • Graphene oxide and reduced graphene oxide were tested as adsorbents for dye removal from water. • Reduced graphene oxide was obtained after laser irradiation of a colloidal suspension of graphene oxide. • Methylene blue was chosen as the dye to test graphene oxide and reduced graphene oxide. - Abstract: The presence of dyes, pharmaceuticals and many other pollutants in wastewaters is critical due to severe effects on the human beings and on the environment. Here, solutions of graphene oxide (GO) and reduced graphene oxide (rGO) were tested as adsorbents for the removal of methylene blue (MB), a cationic dye, from aqueous media. The reduced forms of graphene oxide were obtained after laser irradiation of colloidal suspensions of graphene oxide, obtained by the Hummers and Offeman's method. We observed that both graphene oxide and its reduced forms are excellent adsorbents towards methylene blue. In particular, rGO showed a higher adsorption capacity than GO, suggesting that a strict control of laser irradiation time permits to obtain rGO with different degrees of reduction and therefore the residual oxygenated functional groups may influence the adsorption behaviour more or less. Characterization of the samples by atomic force microscopy (AFM) showed that produced rGO sheets via laser irradiation exhibited a discontinuous surface where some holes could be detected contributing to an enhancement of the rGO surface area that is a higher adsorption capacity.

Contact allergy to ingredients of hair cosmetics - a comparison of female hairdressers and clients based on IVDK 2007-2012 data.

Science.gov (United States)

Uter, Wolfgang; Gefeller, Olaf; John, Swen Malte; Schnuch, Axel; Geier, Johannes

2014-07-01

Cosmetics for bleaching, waving/relaxing and dyeing hair contain well-known allergens, leading to a substantial number of cases of allergic contact dermatitis. To compare the frequency of important contact allergens (i) between two distinct groups of exposed patients, and (ii) with previous surveillance data. On the basis of data collected by the Information Network of Departments of Dermatology (IVDK; www.ivkd.org) between 2007 and 2012 in 824 female hairdressers and 2067 female clients, the current spectrum of contact sensitization to ingredients of hair cosmetics, as contained in different pertinent series, is described. A similar burden of sensitization as in previous analyses was observed, but with some increase in sensitization to oxidative hair dye components in clients. Some allergens mainly affected hairdressers, such as ammonium persulfate (18.7% positive) and glyceryl monothioglycolate (GMTG; still 4.7% positive, with a few cases also in young hairdressers, despite removal from the German market). Hair dyes remain important contact allergens, despite various attempts by the cosmetic industry to introduce hair dyes with lower allergenic potential. The re-emergence of GMTG as an occupational allergen should be considered as a warning signal ('sentinel event') prompting close monitoring. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Influence of bleaching and coloring on ethyl glucuronide content in human hair.

Science.gov (United States)

Petzel-Witt, Silvana; Pogoda, Werner; Wunder, Cora; Paulke, Alexander; Schubert-Zsilavecz, Manfred; Toennes, Stefan W

2018-01-01

Ethyl glucuronide (EtG) is increasingly used in forensic toxicology as a marker for alcohol use in analyses of hair samples, especially in abstinence control. Some cosmetic treatments are considered to markedly reduce the EtG content. In view of especially many women with coloured hair the present study was performed to further investigate the effect of a variety of colouring procedures (bleaching, tinting, permanent and semi-permanent dyeing, henna) on the EtG content. Untreated hair samples (n = 12, EtG 13.9-64.7 pg/mg) were re-analyzed (gas chromatography- negative chemical ionization mass spectrometry, 0.8 pg/mg quantification limit) after different treatment procedures. A decrease of the EtG content of at least 10% occurred in every case. The reduction in comparison to the untreated hair was expectedly high for permanent dyeing and bleaching with 18.1% of the initial content (median, range 0.0-50.9%) and 18.4% (0.0-46.7%), respectively. For henna this was 38.3% (0.0-83.0%), for tinting 70.4% (29.0-90.8%), for semi-permanent dyeing 41.9% (0.0-77.4%). With permanent hair dye the EtG content was decreased to below 7 pg/mg in 10 of 12 cases, in 3 cases even below the LOD (0.2 pg/mg). Surprisingly henna treatment without oxidative component had a marked influence, EtG was below 2 pg/mg in 2 of 12 samples. The study showed that all tested coloration procedures markedly affected the deposited EtG content. Even temporary or henna coloration may have a marked effect. The present data support the recommendation to exclude hair samples with colour manipulations for analysis on the EtG content as a precaution in alcohol abstinence programs. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Homogenous and heterogenous advanced oxidation of two commercial reactive dyes.

Science.gov (United States)

Balcioglu, I A; Arslan, I; Sacan, M T

2001-07-01

Two commercial reactive dyes, the azo dye Reactive Black 5 and the copper phythalocyanine dye Reactive Blue 21, have been treated at a concentration of 75 mg l(-1) by titanium dioxide mediated photocatalytic (TiO2/UV), dark and UV-light assisted Fenton (Fe2+/H2O2) and Fenton-like (Fe3+/H2O2) processes in acidic medium. For the treatment of Reactive Black 5, all investigated advanced oxidation processes were quite effective in terms of colour, COD as well as TOC removal. Moreover, the relative growth inhibition of the azo dye towards the marine algae Dunaliella tertiolecta that was initially 70%, did not exhibit an increase during the studied advanced oxidation reactions and complete detoxification at the end of the treatment period could be achieved for all investigated treatment processes. However, for Reactive Blue 21, abatement in COD and UV-VIS absorbance values was mainly due to the adsorption of the dye on the photocatalyst surface and/or the coagulative effect of Fe3+/Fe2+ ions. Although only a limited fraction of the copper phythalocyanine dye underwent oxidative degradation, 47% of the total copper in the dye was already released after 1 h photocatalytic treatment.

Magnetic graphene oxide for adsorption of organic dyes from aqueous solution

Science.gov (United States)

Drashya, Lal, Shyam; Hooda, Sunita

2018-05-01

Graphene oxide (GO), a 2-D carbon nanomaterial, large surface area, oxygen-containing groups (like: hydroxyl, epoxy and carboxyl) and excellent water dispersibility due to it is good adsorbent dye removal from pollutant water1. But it's difficult to separate GO from water after adsorption. Therefore, Iron oxide was introduced in Graphene oxide by decorating method to make separation more efficient2. We present herein a one step process to prepare Magnetic Graphene oxide (MGO). The Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and Raman Spectroscopy characterized the chemical structure of the MGO composite. The adsorption of dyes onto MGO was studied in relation to initial concentration of Dyes, contact time, adsorbent dose, temperature and pH value of solution. We have studied adsorption capacity of different dyes (Methylene blue and crystal violet) by MGO.

Paraphenylenediamine: Blackening more than just hair

Directory of Open Access Journals (Sweden)

Dilip Gude

2012-01-01

Full Text Available Paraphenylenediamine is an important constituent of hair dye toxicity of which one could herald fatal complications such as rhabdomyolysis, renal failure, angioneurotic edema, and respiratory failure. We present a case of hair dye poisoning that presented with respiratory distress due to laryngeal edema and later developed trismus, subclinical tetany, apnea, and conduction abnormality on electrocardiogram. This case report highlights the need for a thorough toxicological review of the components of any ingested substance.

Trichocyanines: a Red-Hair-Inspired Modular Platform for Dye-Based One-Time-Pad Molecular Cryptography.

Science.gov (United States)

Leone, Loredana; Pezzella, Alessandro; Crescenzi, Orlando; Napolitano, Alessandra; Barone, Vincenzo; d'Ischia, Marco

2015-06-01

Current molecular cryptography (MoCryp) systems are almost exclusively based on DNA chemistry and reports of cryptography technologies based on other less complex chemical systems are lacking. We describe herein, as proof of concept, the prototype of the first asymmetric MoCryp system, based on an 8-compound set of a novel bioinspired class of cyanine-type dyes called trichocyanines. These novel acidichromic cyanine-type dyes inspired by red hair pigments were synthesized and characterized with the aid of density functional theory (DFT) calculations. Trichocyanines consist of a modular scaffold easily accessible via an expedient condensation of 3-phenyl- or 3-methyl-2H-1,4-benzothiazines with N-dimethyl- or o-methoxyhydroxy-substituted benzaldehyde or cinnamaldehyde derivatives. The eight representative members synthesized herein can be classified as belonging to two three-state systems tunable through four different control points. This versatile dye platform can generate an expandable palette of colors and appears to be specifically suited to implement an unprecedented single-use asymmetric molecular cryptography system. With this system, we intend to pioneer the translation of digital public-key cryptography into a chemical-coding one-time-pad-like system.

Degradation of azo dyes by sequential Fenton's oxidation and aerobic biological treatment

International Nuclear Information System (INIS)

Tantak, Nilesh P.; Chaudhari, Sanjeev

2006-01-01

A two stage sequential Fenton's oxidation followed by aerobic biological treatment train was used to achieve decolorization and to enhance mineralization of azo dyes, viz. Reactive Black 5 (RB5), Reactive Blue 13 (RB13), and Acid Orange 7 (AO7). In the first stage, Fenton's oxidation process was used while in the second stage aerobic sequential batch reactors (SBRs) were used as biological process. Study was done to evaluate effect of pH on Fenton's oxidation process. Results reveal that pH 3 was optimum pH for achieving decolorization and dearomatization of dyes by Fenton's process. Degradation of dye was assessed by COD reduction and reduction in aromatic amines (naphthalene chromophores) which was measured by reduction in absorbance at 200 nm. More than 95% of color was removed with Fenton's oxidation process in all dyes. In overall treatment train 81.95, 85.57, and 77.83% of COD reduction was achieved in RB5, RB13, and AO7 dyes, respectively. In the Fenton's oxidation process 56, 24.5, and 80% reduction in naphthalene group was observed in RB5, RB13, and AO7, respectively, which further increased to 81.34, 68.73, and 92% after aerobic treatment. Fenton's oxidation process followed by aerobic SBRs treatment sequence seems to be viable method for achieving significant degradation of azo dye

Zinc oxide based dye sensitized solar cell using eosin – Y as ...

African Journals Online (AJOL)

A zinc oxide based Dye sensitized Solar Cell (DSSC) has been fabricated, using Eosin-Y as the dye adsorbed on a nanocrystalline zinc oxide - fluorine doped tin oxide electrode, for the sensitization of the large band gap semiconductor. The absorption spectrum of Eosin-Y showed high absorption of visible light between ...

Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

Energy Technology Data Exchange (ETDEWEB)

Manwaring, John, E-mail: manwaring.jd@pg.com [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Rothe, Helga [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany); Obringer, Cindy; Foltz, David J.; Baker, Timothy R.; Troutman, John A. [Procter & Gamble Inc., Mason Business Center, Mason, OH 45040 (United States); Hewitt, Nicola J. [SWS, Erzhausen (Germany); Goebel, Carsten [Procter & Gamble Service GmbH, Sulzbacher Str. 40, 65823 Schwalbach am Taunus (Germany)

2015-09-01

Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K{sub m} and V{sub max} values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C{sub max} was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human

Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

International Nuclear Information System (INIS)

Manwaring, John; Rothe, Helga; Obringer, Cindy; Foltz, David J.; Baker, Timothy R.; Troutman, John A.; Hewitt, Nicola J.; Goebel, Carsten

2015-01-01

Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K m and V max values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C max was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human skin explants and

REMOVAL OF REMAZOL ROSSO RB DYE FROM AQUEOUS EFFLUENTS BY HOMOGENOUS FENTON OXIDATION PROCESSES

Directory of Open Access Journals (Sweden)

Carmen Zaharia

2014-06-01

Full Text Available The paper presents some data from our laboratory-setup experiments of homogenous oxidative processes with hydrogen peroxide (i.e. advanced Fenton oxidation processes applied for Remazol Rosso RB dye-containing aqueous systems, especially textile effluents. Therefore, some different operating parameters (including pH, concentration of dye, H2O2 and ferrous ions, oxidation time, temperature, stirring regime, among its were tested for determination of the best performance in effluent decoloration and dye removal, meaning the optimal values of each studied parameters for highest decoloration or dye removal.

Ultrafast electron and energy transfer in dye-sensitized iron oxide and oxyhydroxide nanoparticles

DEFF Research Database (Denmark)

Gilbert, Benjamin; Katz, Jordan E.; Huse, Nils

2013-01-01

photo-initiated interfacial electron transfer. This approach enables time-resolved study of the fate and mobility of electrons within the solid phase. However, complete analysis of the ultrafast processes following dye photoexcitation of the sensitized iron(iii) oxide nanoparticles has not been reported....... We addressed this topic by performing femtosecond transient absorption (TA) measurements of aqueous suspensions of uncoated and DCF-sensitized iron oxide and oxyhydroxide nanoparticles, and an aqueous iron(iii)–dye complex. Following light absorption, excited state relaxation times of the dye of 115...... a four-state model of the dye-sensitized system, finding electron and energy transfer to occur on the same ultrafast timescale. The interfacial electron transfer rates for iron oxides are very close to those previously reported for DCF-sensitized titanium dioxide (for which dye–oxide energy transfer...

Oxidative treatment characteristics of biotreated textile-dyeing wastewater and chemical agents used in a textile-dyeing process by advanced oxidation process.

Science.gov (United States)

Lim, B R; Hu, H Y; Ahn, K H; Fujie, K

2004-01-01

The oxidative treatment characteristics of biotreated textile-dyeing wastewater and typical chemicals such as desizing, scouring, dispersing and swelling agents used in the textile-dyeing process by advanced oxidation process were experimentally studied. The refractory organic matters remained in the effluent of biological treatment process without degradation may be suitable for the improvement of biodegradability and mineralized to CO2 by combined ozonation with and without hydrogen peroxide. On the other hand, the refractory chemicals contained in the scouring agent A and swelling agent may not be mineralized and their biodegradability may not be improved by ozonation. However, the BOD/DOC ratio of scouring agent B increased from 0.3 to 0.45 after ozonation. Based on the results described above, advanced treatment process involving the ozonation without and with the addition of hydrogen peroxide, followed by biological treatment was proposed for the treatment of refractory wastewater discharged from the textile-dyeing process.

Can long-term alopecia occur after appropriate pulsed-dye laser therapy in hair-bearing sites? Pediatric dermatologists weigh in.

Science.gov (United States)

Feldstein, Stephanie; Totri, Christine R; Friedlander, Sheila F

2015-03-01

The risk of long-term alopecia after pulsed-dye laser (PDL) therapy is unknown. To identify how many practitioners treat hair-bearing sites with PDL and how commonly long-term alopecia occurs, the authors queried pediatric dermatologists about their experiences using this modality. A survey was designed to evaluate the frequency of and factors contributing to long-term alopecia after PDL treatment of port-wine stains (PWS). "Long-term" was defined as no sign of hair regrowth after several years of nontreatment. The survey was administered to attendees at the 2014 Society for Pediatric Dermatology biannual meeting. Sixty-four pediatric dermatologists completed the survey, 50 of whom had experience using PDL. Of these physicians, 86% have used PDL to treat PWS of the eyebrow and 80% have treated PWS of the scalp. Over one-quarter of respondents (25.5%) using PDL on hair-bearing areas had at least 1 of their patients develop long-term alopecia after PDL treatment. The incidence of long-term alopecia after PDL treatment in the surveyed population was 1.5% to 2.6%. The occurrence of long-term alopecia at hair-bearing sites after treatment with PDL may be greater than previously thought. Because the majority of physicians using PDL treat hair-bearing areas, prospective studies are needed to more accurately determine the risk of long-term alopecia and the factors that contribute to it.

Photo-oxidative degradation of Chicago Sky Blue azo dye on transition metal oxide electrodes

Energy Technology Data Exchange (ETDEWEB)

Slote, J.; Luo, J.; Hepel, M. [State Univ. of New York at Potsdam, NY (United States). Dept. of Chemistry; Zhong, C.-J. [State Univ. of New York at Binghamton, NY (United States). Dept. of Chemistry

2003-07-01

Every day, an average of 128 tons of dye staffs are discharged into waste water, causing environmental harm. The authors discussed the photo-electrical method for separating the semiconductor catalyst particles from the solution and direct control of the interfacial potential as an efficient and convenient method for degrading organic dyes. Photocurrent-potential measurements were made using a standard photoelectrochemical setup. It involved a microcomputer-controlled potentiostat and a 500 watts (W) quartz halogen lamp as the illumination source. The measurement of the photocurrent represented the difference between the current under illumination and current in the dark. Three-electrode electrochemical cells were used for all experiments. The best results concerning the degradation of dyes were obtained with tungsten oxides (WO3) and molybdenum oxides (MoO3) electrodes. Confirmation that the dyes had been fully degraded was obtained by performing absorbance measurements and a high performance liquid chromatography (HPLC) analysis of the samples after degradation. The effect on the rate of decolorisation process of Chicago Sky Blue, a diazo dye, and other dyes, of pH, potential, concentration, and type of supporting electrolyte was examined. The supporting electrolyte was found to have a strong influence on the degradation of diazo dye. Illumination with visible light yielded lower degradation rates than that with ultraviolet-visible light. It appears that Chicago Sky Blue dye sensitizes the semiconductor to expand the absorption of light energy well into visible range, despite the photoelectrochemical degradation of the dye being mainly induced by the ultraviolet light. The authors proposed the mechanisms of the reactions occurring during the photodegradation process. 6 refs., 1 fig.

Degradation of the ethyl glucuronide content in hair by hydrogen peroxide and a non-destructive assay for oxidative hair treatment using infra-red spectroscopy.

Science.gov (United States)

Ammann, Dominic; Becker, Roland; Kohl, Anka; Hänisch, Jessica; Nehls, Irene

2014-11-01

The assessment of quantification results of the alcohol abuse marker ethyl glucuronide (EtG) in hair in comparison to the cut-off values for the drinking behavior may be complicated by cosmetic hair bleaching. Thus, the impact of increasing exposure to hydrogen peroxide on the EtG content of hair was investigated. Simultaneously, the change of absorbance in the range of 1000-1100 cm(-1) indicative for the oxidation of cystine was investigated non-destructively by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) using pulverized portions of the respective hair samples. Hair samples treated with hydrogen peroxide consistently displayed a significantly increased absorbance at 1040 cm(-1) associated with the formation of cysteic acid. The EtG content decreased significantly if the hair was treated with alkaline hydrogen peroxide as during cosmetic bleaching. It could be shown that ATR-FTIR is capable of detecting an exposure to hydrogen peroxide when still no brightening was visible and already before the EtG content deteriorated significantly. Thus, hair samples suspected of having been exposed to oxidative treatment may be checked non-destructively by a readily available technique. This assay is also possible retrospectively after EtG extraction and using archived samples. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

An investigation to adopt zero liquid discharge in textile dyeing using advanced oxidation processes

International Nuclear Information System (INIS)

Ahmd, F.

2015-01-01

In this study, a novel idea of using ozone oxidation at the end of reactive dyeing process was explored in order to achieve zero discharge dyeing. An advanced oxidative treatment was given during the dyeing process to remove unfixed and hydrolyzed reactive dyes from cotton substrate. Three different shades were dyed using vinylsulphone reactive class of dyes. At the end of fixation step, washing of fabrics was carried out using appropriate quantities of ozone in the process. Ozone oxidation continued until the liquor was decolorized around 95-100% and COD (Chemical Oxygen Demand) was reduced about 80-90%, thus achieving zero liquid discharge dyeing process. The decolouration efficiency of wastewater was regarded as an indicative of removal of dyes from the textile materials because fabric was being washed continuously in the same liquor. Fabric samples dyed with conventional and new methods were compared in terms of change in shade, colourfastness properties, colour stripping, and fabric appearance. Overall results showed that the use of ozone during reactive dyeing can result in less water consumption, reduced process time, and zero discharge of coloured effluents from textile dyeing factories. (author)

Preparation of surface modified zinc oxide nanoparticle with high capacity dye removal ability

International Nuclear Information System (INIS)

Mahmoodi, Niyaz Mohammad; Najafi, Farhood

2012-01-01

Highlights: ► Amine-functionalized zinc oxide nanoparticle (AFZON) was synthesized. ► Isotherm and kinetics data followed Langmuir isotherm and pseudo-second order kinetic model, respectively. ► Q 0 of ZON for AB25, DR23 and DR31 was 20, 12 and 15 mg/g, respectively. ► Q 0 of AFZON for AB25, DR23 and DR31 was 1250, 1000 and 1429 mg/g, respectively. ► AFZON was regenerated at pH 12. -- Abstract: In this paper, the surface modification of zinc oxide nanoparticle (ZON) by amine functionalization was studied to prepare high capacity adsorbent. Dye removal ability of amine-functionalized zinc oxide nanoparticle (AFZON) and zinc oxide nanoparticle (ZON) was also investigated. The physical characteristics of AFZON were studied using Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Acid Blue 25 (AB25), Direct Red 23 (DR23) and Direct Red 31 (DR31) were used as model compounds. The effect of operational parameters such as dye concentration, adsorbent dosage, pH and salt on dye removal was evaluated. The isotherm and kinetic of dye adsorption were studied. The maximum dye adsorption capacity (Q 0 ) was 20 mg/g AB25, 12 mg/g DR23 and 15 mg/g DR31 for ZON and 1250 mg/g AB25, 1000 mg/g DR23 and 1429 mg/g DR31 for AFZON. It was found that dye adsorption followed Langmuir isotherm. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetics. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 90% AB25, 86% for DR23 and 90% for DR31 were achieved in aqueous solution at pH 12. Based on the data of the present investigation, it can be concluded that the AFZON being an adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored aqueous solutions.

Testing strategies in mutagenicity and genetic toxicology: an appraisal of the guidelines of the European Scientific Committee for Cosmetics and Non-Food Products for the evaluation of hair dyes.

Science.gov (United States)

Kirkland, D J; Henderson, L; Marzin, D; Müller, L; Parry, J M; Speit, G; Tweats, D J; Williams, G M

2005-12-30

The European Scientific Committee on Cosmetics and Non-Food Products (SCCNFP) guideline for testing of hair dyes for genotoxic/mutagenic/carcinogenic potential has been reviewed. The battery of six in vitro tests recommended therein differs substantially from the batteries of two or three in vitro tests recommended in other guidelines. Our evaluation of the chemical types used in hair dyes and comparison with other guidelines for testing a wide range of chemical substances, lead to the conclusion that potential genotoxic activity may effectively be determined by the application of a limited number of well-validated test systems that are capable of detecting induced gene mutations and structural and numerical chromosomal changes. We conclude that highly effective screening for genotoxicity of hair dyes can be achieved by the use of three assays, namely the bacterial gene mutation assay, the mammalian cell gene mutation assay (mouse lymphoma tk assay preferred) and the in vitro micronucleus assay. These need to be combined with metabolic activation systems optimised for the individual chemical types. Recent published evidence [D. Kirkland, M. Aardema, L. Henderson, L. Müller, Evaluation of the ability of a battery of three in vitro genotoxicity tests to discriminate rodent carcinogens and non-carcinogens. I. Sensitivity, specificity and relative predictivity, Mutat. Res. 584 (2005) 1-256] suggests that our recommended three tests will detect all known genotoxic carcinogens, and that increasing the number of in vitro assays further would merely reduce specificity (increase false positives). Of course there may be occasions when standard tests need to be modified to take account of special situations such as a specific pathway of biotransformation, but this should be considered as part of routine testing. It is clear that individual dyes and any other novel ingredients should be tested in this three-test battery. However, new products are formed on the scalp by

The role of rare earth oxide nanoparticles in suppressing the photobleaching of fluorescent organic dyes

Science.gov (United States)

Guha, Anubhav; Basu, Anindita

2013-03-01

Organic dyes are widely used for both industrial as well as in scientific applications such as the fluorescent tagging of materials. However the process of photobleaching can rapidly degrade dye fluorescence rendering the material non-functional. Thus exploring novel methods for preventing photobleaching can have widespread benefits. In this work we show that the addition of minute quantities of rare earth (RE) oxide nanoparticles can significantly suppress the photobleaching of dyes. The fluorescence of Rhodamine and AlexaFluor dyes was measured as a function of time with and without the addition of CeO2 and La2O3 nanoparticle additives (two RE oxides that contain an oxygen vacancy based defect structure), as well as with FeO nanoparticles (which has an oxygen excess stoichiometry). We find that the rare earth oxides significantly prolonged the lifetimes of the dyes. The results allow us to develop a model based upon the presence of oxygen vacancies defects that allow the RE oxides to act as oxygen scavengers. This enables the RE oxide particles to effectively remove reactive oxygen free radicals generated in the dye solutions during the photoabsorption process. Current affiliation: Harvard University

Towards a "free radical theory of graying": melanocyte apoptosis in the aging human hair follicle is an indicator of oxidative stress induced tissue damage.

Science.gov (United States)

Arck, Petra Clara; Overall, Rupert; Spatz, Katharina; Liezman, Christiane; Handjiski, Bori; Klapp, Burghard F; Birch-Machin, Mark A; Peters, Eva Milena Johanne

2006-07-01

Oxidative stress is generated by a multitude of environmental and endogenous challenges such as radiation, inflammation, or psychoemotional stress. It also speeds the aging process. Graying is a prominent but little understood feature of aging. Intriguingly, the continuous melanin synthesis in the growing (anagen) hair follicle generates high oxidative stress. We therefore hypothesize that hair bulb melanocytes are especially susceptible to free radical-induced aging. To test this hypothesis, we subjected human scalp skin anagen hair follicles from graying individuals to macroscopic and immunohistomorphometric analysis and organ culture. We found evidence of melanocyte apoptosis and increased oxidative stress in the pigmentary unit of graying hair follicles. The "common" deletion, a marker mitochondrial DNA-deletion for accumulating oxidative stress damage, occurred most prominently in graying hair follicles. Cultured unpigmented hair follicles grew better than pigmented follicles of the same donors. Finally, cultured pigmented hair follicles exposed to exogenous oxidative stress (hydroquinone) showed increased melanocyte apoptosis in the hair bulb. We conclude that oxidative stress is high in hair follicle melanocytes and leads to their selective premature aging and apoptosis. The graying hair follicle, therefore, offers a unique model system to study oxidative stress and aging and to test antiaging therapeutics in their ability to slow down or even stop this process.

Investigation on Fluorescence Quenching Mechanism of Perylene Diimide Dyes by Graphene Oxide

Directory of Open Access Journals (Sweden)

Yuzhen Zhao

2016-11-01

Full Text Available Perylene diimide derivatives were used as probes to investigate the effect of the molecular structures on the fluorescence quenching mechanism in a perylene diimide/graphene oxide system. The electrons transferred from the excited state of dyes to the conductive band of graphene oxide with different concentrations were determined by fluorescence spectra. The results indicated that the quenching efficiency of perylene diimides by graphene oxide was not only dependent on the difference between the lowest unoccupied molecular orbital level of dyes and the conduction band of the graphene oxide, but also mainly on the difference in the molecular structures.

Advanced oxidation of acid and reactive dyes

DEFF Research Database (Denmark)

Arslan-Alaton, I.; Gursoy, B.H.; Schmidt, Jens Ejbye

2008-01-01

M) for 10:hsp sp="0.25" min Fenton treatment at pH 3, resulting in reduced chemical oxygen demand and dissolved organic carbon removal efficiencies; only acetate was detected as a stable dye oxidation end product. During anaerobic digestion, 100, 29% and no inhibition in methane production was observed...

Monodispersed Zinc Oxide Nanoparticle-Dye Dyads and Triads

Energy Technology Data Exchange (ETDEWEB)

Gladfelter, Wayne L. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry; Blank, David A. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry; Mann, Kent R. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemistry

2017-06-22

The overall energy conversion efficiency of photovoltaic cells depends on the combined efficiencies of light absorption, charge separation and charge transport. Dye-sensitized solar cells are photovoltaic devices in which a molecular dye absorbs light and uses this energy to initiate charge separation. The most efficient dye-sensitized solar cells (DSSCs) use nanocrystal titanium dioxide films to which are attached ruthenium complexes. Numerous studies have provided valuable insight into the dynamics of these and analogous photosystems, but the lack of site homogeneity in binding dye molecules to metal oxide films and nanocrystals (NCs) is a significant impediment to extracting fundamental details about the electron transfer across the interface. Although zinc oxide is emerging as a potential semiconducting component in DSSCs, there is less known about the factors controlling charge separation across the dye/ZnO interface. Zinc oxide crystallizes in the wurtzite lattice and has a band gap of 3.37 eV. One of the features that makes ZnO especially attractive is the remarkable ability to control the morphology of the films. Using solution deposition processes, one can prepare NCs, nanorods and nanowires having a variety of shapes and dimensions. This project solved problems associated with film heterogeneity through the use of dispersible sensitizer/ZnO NC ensembles. The overarching goal of this research was to study the relationship between structure, energetics and dynamics in a set of synthetically controlled donor-acceptor dyads and triads. These studies provided access to unprecedented understanding of the light absorption and charge transfer steps that lie at the heart of DSSCs, thus enabling significant future advances in cell efficiencies. The approach began with the construction of well-defined dye-NC dyads that were sufficiently dispersible to allow the use of state of the art pulsed laser spectroscopic and kinetic methods to understand the charge transfer

In Vitro Methodologies to Evaluate the Effects of Hair Care Products on Hair Fiber

Directory of Open Access Journals (Sweden)

Robson Miranda da Gama

2017-01-01

Full Text Available Consumers use different hair care products to change the physical appearance of their hair, such as shampoos, conditioners, hair dye and hair straighteners. They expect cosmetics products to be available in the market to meet their needs in a broad and effective manner. Evaluating efficacy of hair care products in vitro involves the use of highly accurate equipment. This review aims to discuss in vitro methodologies used to evaluate the effects of hair care products on hair fiber, which can be assessed by various methods, such as Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Force Microscopy, Optical Coherence Tomography, Infrared Spectroscopy, Raman Spectroscopy, Protein Loss, Electrophoresis, color and brightness, thermal analysis and measuring mechanical resistance to combing and elasticity. The methodology used to test hair fibers must be selected according to the property being evaluated, such as sensory characteristics, determination of brightness, resistance to rupture, elasticity and integrity of hair strain and cortex, among others. If equipment is appropriate and accurate, reproducibility and ease of employment of the analytical methodology will be possible. Normally, the data set must be discussed in order to obtain conclusive answers to the test.

Hair cosmetics

OpenAIRE

Nina Madnani; Kaleem Khan

2013-01-01

The hair cosmetic industry has undergone a revolutionary change over the last two decades. The focus has dramatically veered from merely cleaning to repair, increasing the tensile strength, reducing oxidative damage, and stimulating growth. Newer shorter procedures to make hair look naturally more lustrous, smooth, and manageable have evolved. Specialized grooming products have been formulated to cleanse, calm, and condition the hair, and are tailored for different hair-types, for example, dr...

Effect of hair care and hair cosmetics on the concentrations of fatty acid ethyl esters in hair as markers of chronically elevated alcohol consumption.

Science.gov (United States)

Hartwig, Sven; Auwärter, Volker; Pragst, Fritz

2003-01-28

Fatty acid ethyl esters (FAEE) can be used as alcohol markers in hair. It was investigated in this study whether this diagnostic method is disturbed by hair care and hair cosmetics. Traces of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate were detected in all of 49 frequently applied hair care products by headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The highest concentration was 0.003% in a hair wax. From experiments with separated hair samples of alcoholics as well as from the evaluation of the FAEE concentrations and the data about hair care of 75 volunteers (alcoholics, social drinkers and teetotalers) follows that usual shampooing, permanent wave, dyeing, bleaching or shading are of minor importance as compared to the drinking amount and other individual features. However, false positive results were found after daily treatment with a hair lotion containing 62.5% ethanol, with a deodorant and with a hair spray. As an explanation, it is assumed that FAEE are formed in the sebum glands also after regular topical application of products with a higher ethanol content.

Oxidative stability of yogurt with added lutein dye.

Science.gov (United States)

Domingos, L D; Xavier, A A O; Mercadante, A Z; Petenate, A J; Jorge, R A; Viotto, W H

2014-02-01

This study evaluated the effect of adding lutein dye on the oxidative stability of yogurt during 35 d of refrigerated storage, in the presence and absence of light. Yogurts manufactured without and with the equivalent of 1.5mg of lutein in 120 g of the final product were characterized for their total carotenoid and riboflavin contents, and the behaviors of both riboflavin and lutein were monitored during storage. A decrease in riboflavin content occurred, with concurrent appearance of its derived-oxidation products in the yogurts without added lutein and exposed to light during storage. The yogurts with added lutein dye showed constant lutein and riboflavin contents throughout storage both for the samples stored under light and for those stored in the dark. Yogurts (120 g) with the addition of 0.5, 1.5, and 2.5mg of lutein dye were evaluated for their sensory acceptance, and the statistical analysis showed no differences between the samples for the attributes of aroma and flavor. These results indicate that the added lutein remained stable throughout the storage period and conferred protection for the riboflavin against photooxidation, preserving the quality of the yogurts. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The oxidative response and viable reaction mechanism of the textile dyes by fenton reagent

International Nuclear Information System (INIS)

Masooda, Q.; Hijira, T.; Sitara, M.; Sehar, M.; Sundus, A.; Mohsin, A.

2017-01-01

The mechanism of the degradation of the Reactive Red 239 and Reactive Blue 19 by Fenton reagent was studied by advanced oxidation process in aqueous medium. The spectroscopic technique was adopted for the measurements of dye concentration. Moreover they were determined at 540 nm and 590 nm, respectively. Kinetics of the reaction was studied under the effect of concentration of reactive dyes, concentration of oxidant were followed under pseudo first order condition and found to influence the catalytic mechanism. The pH of the medium, vibrant response of several cations and anions and influence of ionic strength on the reaction kinetics were also monitored. Physical evidences for the degradation and mineralization of the dyes were evaluated by Lime water test, Ring Test and TLC test also confirmed the degradation of dye. Inhibitory effects of dyes were observed by CO3-, HCO3-, HPO42-, Cl-, I- Al3+ and Na+. Thermodynamic activation parameters in the oxidation reaction were studied and mode of mechanism was suggested on the basic of these parameters. This study explored the safe and eco friendly degradation of the textile dyes under Pseudo first order rate constant. It was observed that Fenton assisted degradation of the dyes under controlled conditions was found to be favorable for the treatment of textile wastewater. Moreover compared to other chemical methods it is effective and harmless to the environment. (author)

Kinetics and mechanism of azo dye destruction in advanced oxidation processes

International Nuclear Information System (INIS)

Wojnarovits, L.; Palfi, T.; Takacs, E.

2007-01-01

The kinetics and mechanism of dye destruction in advanced oxidation processes is discussed on the example of Apollofix Red (Ar-28) radiolysis in aqueous solution. When the reactive intermediate reacts with the color bearing part of the molecule causing with nearly 100% efficiency destruction of the conjugation, the dose dependence, or time dependence of color disappearance is linear. In this case, spectrophotometry can be used to follow-up dye decomposition. Linear dependence was observed when hydrated electrons or hydrogen atoms reacted with the dye. In hydroxyl radical reactions some colored products form with spectra similar to those of the starting dye molecules. For that reason, spectrophotometry gives false result about the intact dye molecule concentration. Analysis by the HPLC reveals logarithmic time dependence in agreement with a theoretical model developed

Nanobeads of zinc oxide with rhodamine B dye as a sensitizer for dye sensitized solar cell application

Energy Technology Data Exchange (ETDEWEB)

Baviskar, P.K. [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001, MS (India); Zhang, J.B. [Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Gupta, V.; Chand, S. [Organic and Hybrid Solar Cell, Physics of Energy Harvesting Division, Dr. K. S. Krishnan Marg, National Physical Laboratory, New Delhi 110012 (India); Sankapal, B.R., E-mail: brsankapal@rediffmail.com [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001, MS (India)

2012-01-05

Highlights: > Synthesis of ZnO film was done at room temperature (27 deg. C). > Simple and inexpensive chemical bath deposition method was employed. > The as deposited film consists of mixed phases of hydroxide and oxide. > The post annealing was done at 200 deg. C in order to remove hydroxide phase. > Low-cost, metal free Rhodamine B dye was used for DSSC application. - Abstract: Cost effective, ruthenium metal free rhodamine B dye has been chemically adsorbed on ZnO films consisting of nanobeads to serve as a photo anode in dye sensitized solar cells. These ZnO films were chemically synthesized at room temperature (27 deg. C) on to fluorine doped tin oxide (FTO) coated glass substrates followed by annealing at 200 deg. C. These films consisting of inter connected nanobeads (20-40 nm) which are due to the agglomeration of very small size particles (3-5 nm) leading to high surface area. The film shows wurtzite structure having high crystallinity with optical direct band gap of 3.3 eV. Optical absorbance measurements for rhodamine B dye covered ZnO film revealed the good coverage in the visible region (460-590 nm) of the solar spectrum. With poly-iodide liquid as an electrolyte, device exhibits photon to electric energy conversion efficiency ({eta}) of 1.26% under AM 1.5G illumination at 100 mW/cm{sup 2}.

Research Advances: Pacific Northwest National Laboratory Finds New Way to Detect Destructive Enzyme Activity--Hair Dye Relies on Nanotechnology--Ways to Increase Shelf Life of Milk

Science.gov (United States)

King, Angela G.

2007-01-01

Recent advances in various research fields are described. Scientists at the Pacific Northwest National Laboratory have found a new way to detect destructive enzyme activity, scientists in France have found that an ancient hair dye used by ancient people in Greece and Rome relied on nanotechnology and in the U.S. scientists are developing new…

Dye-sensitized solar cells based on different nano-oxides on plastic PET substrate

Science.gov (United States)

Mikula, Milan; Gemeiner, Pavol; Beková, Zuzana; Dvonka, Vladimír; Búc, Dalibor

2015-01-01

Polyethylene-terephthalate (PET) foils and glass slides coated with thin conductive layers were used as substrates for TiO2 or ZnO based photoactive electrodes of dye-sensitized solar cells (DSSC) with organo-metallic Ru-dye, standard iodine electrolyte and Pt coated FTO/glass counterelectrode (CE). Different compositions of nanoparticle oxides in forms of alcohol pastes as well as the CE paste were applied onto the substrates by screen printing or by doctor blade techniques. Photocurrents and I-V loading characteristics were measured depending on the solar cell structure and preparation, including the oxide composition, electrode conductivity and the dye type. The influence of thin TiO2 blocking layer prepared by sol-gel technique is also discussed.

Comparison in decoloration efficiency among radiation, ultraviolet ray and Fenton oxidation treatment for aqueous solution of dyes

International Nuclear Information System (INIS)

Shimokawa, Toshishige; Sawai, Takeshi

1984-01-01

To establish the methods of oxidation and decomposition treatment for dyeing waste water, the processes by radiation, ultraviolet ray and Fenton oxidation were examined comparatively for the decoloration efficiency. The dyes tested were commercially available reactive dyes, RBO-3R, DBR-BB, MBY-6GS and RBB-R. In the radiation process, the dye solution was irradiated with gamma ray of cobalt-60 while blowing air through it. Radiation process and Fenton oxidation were excellent for decoloration. Ultraviolet ray was low in the treatment efficiency, so it is not practical. In the radiation process, the addition of a reagent and the adjustment of pH are not required unlike the case of the Fenton oxidation process. Its continuous operation is also possible, so it is a highly practical means. (Mori, K.)

Dye-sensitized solar cells based on nanostructured zinc oxide

Energy Technology Data Exchange (ETDEWEB)

Conradt, Jonas; Maier-Flaig, Florian; Sartor, Janos; Fallert, Johannes [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Szmytkowski, Jedrzej; Kalt, Heinz [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Reinhard, Manuel; Colsmann, Alexander [Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Lemmer, Uli [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Balaban, Teodor Silviu [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology, Karlsruhe (Germany)

2009-07-01

Hybrid solar cells represent a promising (cost-efficient) alternative to pure inorganic solar cells. We present dye-sensitized solar cells (DSSC) which are based on a zinc oxide (ZnO) electrode covered with a ruthenium dye. Our work focuses on the morphology of the ZnO electrode and its impact on the photovoltaic performance of the solar cell. Nanocrystalline ZnO powder layers and arrays of nanorods are incorporated into the DSSCs. The ZnO nanorods are grown by vapor transport deposition. The morphology and doping concentration of the rods can be controlled by the choice of substrate material, growth condition and catalytic metal layers. The nanorod arrays are expected to fasten the electron transport towards the anode and thereby improve the solar cell efficiency. In addition, novel self-assembling (porphyrin) dyes are tested as sensitizer within a DSSC.

An overview on the removal of synthetic dyes from water by electrochemical advanced oxidation processes.

Science.gov (United States)

Nidheesh, P V; Zhou, Minghua; Oturan, Mehmet A

2018-04-01

Wastewater containing dyes are one of the major threats to our environment. Conventional methods are insufficient for the removal of these persistent organic pollutants. Recently much attention has been received for the oxidative removal of various organic pollutants by electrochemically generated hydroxyl radical. This review article aims to provide the recent trends in the field of various Electrochemical Advanced Oxidation Processes (EAOPs) used for removing dyes from water medium. The characteristics, fundamentals and recent advances in each processes namely anodic oxidation, electro-Fenton, peroxicoagulation, fered Fenton, anodic Fenton, photoelectro-Fenton, sonoelectro-Fenton, bioelectro-Fenton etc. have been examined in detail. These processes have great potential to destroy persistent organic pollutants in aqueous medium and most of the studies reported complete removal of dyes from water. The great capacity of these processes indicates that EAOPs constitute a promising technology for the treatment of the dye contaminated effluents. Copyright © 2018 Elsevier Ltd. All rights reserved.

One pot synthesis of multi-functional tin oxide nanostructures for high efficiency dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Wali, Qamar; Fakharuddin, Azhar; Yasin, Amina; Ab Rahim, Mohd Hasbi; Ismail, Jamil; Jose, Rajan, E-mail: rjose@ump.edu.my

2015-10-15

Photoanode plays a key role in dye sensitized solar cells (DSSCs) as a scaffold for dye molecules, transport medium for photogenerated electrons, and scatters light for improved absorption. Herein, tin oxide nanostructures unifying the above three characteristics were optimized by a hydrothermal process and used as photoanode in DSSCs. The optimized morphology is a combination of hollow porous nanoparticles of size ∼50 nm and micron sized spheres with BET surface area (up to 29 m{sup 2}/g) to allow large dye-loading and light scattering as well as high crystallinity to support efficient charge transport. The optimized morphology gave the highest photovoltaic conversion efficiency (∼7.5%), so far achieved in DSSCs with high open circuit voltage (∼700 mV) and short circuit current density (∼21 mA/cm{sup 2}) employing conventional N3 dye and iodide/triiodide electrolyte. The best performing device achieved an incident photon to current conversion efficiency of ∼90%. The performance of the optimized tin oxide nanostructures was comparable to that of conventional titanium based DSSCs fabricated at similar conditions. - Graphical abstract: Tin oxide hollow nanostructure simultaneously supporting improved light scattering, dye-loading, and charge transport yielded high photovoltaic conversion efficiency in dye-sensitized solar cells. - Highlights: • Uniformly and bimodelly distributed tin oxide hollow nanospheres (HNS) are synthesized. • Uniform HNS are of size ∼10 nm; bimodel HNS has additional size up to ∼800 nm. • They are evaluated as photoelectrodes in dye-sensitized solar cells (DSSCs). • The uniform HNS increase dye-loading and the larger increase light scattering in DSSCs. • Photo conversion efficiency ∼7.5% is achieved using bimodel HNS.

Photocatalytic degradation and photo-Fenton oxidation of Congo red dye pollutants in water using natural chromite—response surface optimization

Science.gov (United States)

Shaban, Mohamed; Abukhadra, Mostafa R.; Ibrahim, Suzan S.; Shahien, Mohamed. G.

2017-12-01

Refined natural Fe-chromite was characterized by XRD, FT-IR, reflected polarized microscope, XRF and UV spectrophotometer. Photocatalytic degradation and photo-Fenton oxidation of Congo red dye by Fe-chromite was investigated using 1 mL H2O2. The degradation of dye was studied as a function of illumination time, chromite mass, initial dye concentration, and pH. Fe-chromite acts as binary oxide system from chromium oxide and ferrous oxide. Thus, it exhibits photocatalytic properties under UV illumination and photo-Fenton oxidation after addition of H2O2. The degradation in the presence of H2O2 reached the equilibrium stage after 8 h (59.4%) but in the absence of H2O2 continued to 12 h (54.6%). Photocatalytic degradation results fitted well with zero, first order and second order kinetic model but it represented by second order rather than by the other models. While the photo-Fenton oxidation show medium fitting with the second order kinetic model only. The values of kinetic rate constants for the photo-Fenton oxidation were greater than those for the photocatalytic degradation. Thus, degradation of Congo red dye using chromite as catalyst is more efficient by photo-Fenton oxidation. Based on the response surface analysis, the predicted optimal conditions for maximum removal of Congo red dye by photocatalytic degradation (100%) were 12 mg/l, 0.14 g, 3, and 11 h for dye concentration, chromite mass, pH, and illumination time, respectively. Moreover, the optimum condition for photo-Fenton oxidation of dye (100%) is 13.5 mg/l, 0.10 g, 4, and 10 h, respectively.

Medicinal Herbs Affecting Gray Hair in Iranian Traditional Medicine.

Science.gov (United States)

Rameshk, Maryam; Khandani, Shahram Kalantari; Raeiszadeh, Mahboobeh

2016-05-01

The presence of hair plays an important role in people's overall physical appearance and self-perception. As a result of increased life expectancy, the desire to look youthful plays a bigger role than ever.The use of medicinal plants is as old as mankind and the market will face many new products containing natural oils and herbs in coming years. In traditional Iranian medicine, many plants and herbal formulations are reported for hair growth as well as the improvement in hair quality. The aim of this article is to introduce effective medicinal plants in traditional Iranian medicine to prevent gray hair and advocate them as the new products. The present investigation is an overview study and has been codified by library search in the main sources of traditional Iranian medicine. In traditional Iranian medicine, three types of formulations are proposed to prevent gray hair, namely (i) treatment compounds, (ii) preventive compounds, and (iii) hair dyes to color gray hairs. Our search showed that the main parts of a plant that is used in the treatment and preventive compounds are seeds and fruits. These are primarily in the form of topical oil or oral compound (electuary). The majority of plant parts used in hair dyes is from the fruit and/or leaves. Natural products are highly popular and the use of plant extracts in formulations is on the rise. This is because synthetic based product may cause health hazards with several side effects. Considering the increased popularity of herbal drugs in hair care, it is worthwhile to conduct systemic investigation on the production and efficacy of these drugs. We trust that our investigation would encourage the use of traditional Iranian medicine in future hair care products.

Dye-sensitized solar cell architecture based on indium-tin oxide nanowires coated with titanium dioxide

International Nuclear Information System (INIS)

Joanni, Ednan; Savu, Raluca; Sousa Goes, Marcio de; Bueno, Paulo Roberto; Nei de Freitas, Jilian; Nogueira, Ana Flavia; Longo, Elson; Varela, Jose Arana

2007-01-01

A new architecture for dye-sensitized solar cells is employed, based on a nanostructured transparent conducting oxide protruding from the substrate, covered with a separate active oxide layer. The objective is to decrease electron-hole recombination. The concept was tested by growing branched indium-tin oxide nanowires on glass using pulsed laser deposition followed by deposition of a sputtered titanium dioxide layer covering the wires. The separation of charge generation and charge transport functions opens many possibilities for dye-sensitized solar cell optimization

A multi-institutional joint study of contact dermatitis related to hair colouring and perming agents in Japan.

Science.gov (United States)

Ito, Akiko; Nishioka, Kazue; Kanto, Hiromi; Yagami, Akiko; Yamada, Shigeki; Sugiura, Mariko; Yasunaga, Chihiro; Yoshii, Keiko; Kobayashi, Hiromi; Adachi, Atsuko; Ikezawa, Yuko; Washizaki, Kumiko; Inui, Shigeki; Miyazawa, Hitoshi; Oiso, Naoki; Nakata, Tokio; Matsunaga, Kayoko

2017-07-01

In Japan, allergic contact dermatitis caused by hair colouring agents is a considerable problem for those occupationally exposed and also for consumers. Over the last 20 years, p-phenylenediamine (PPD) has been a common allergen, with ∼7% positive patch test reactions. To investigate which ingredients caused allergic contact dermatitis related to hair dye and perming solutions in Japan, to assess whether PPD is suitable for screening for hair dye allergy, and to propose allergens for a Japanese hairdresser series. We selected 19 hair cosmetic allergens, including PPD, Bandrowski's base, cysteamine HCl, and ammonium thioglycolate. Altogether 203 patients (26 males and 177 females) with suspected contact allergy to hair colouring or perming solutions at 14 hospitals in Japan were included. The highest prevalence of positive reactions (35.1%) was for PPD. p-Methylaminophenol and o-aminophenol were often positive, both in the PPD-positive and in the PPD-negative patients. Moreover, cysteamine HCl often yielded positive test reactions. PPD is insufficient to diagnose contact allergy caused by to hair dyes. We recommend 13 allergens to be included in a Japanese hairdresser series. © 2017 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.

Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro.

Science.gov (United States)

Manwaring, John; Rothe, Helga; Obringer, Cindy; Foltz, David J; Baker, Timothy R; Troutman, John A; Hewitt, Nicola J; Goebel, Carsten

2015-09-01

Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis-Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte Km and Vmax values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and Cmax was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. Copyright © 2015. Published by Elsevier Inc.

Photocatalytic oxidation of a reactive azo dye and evaluation of the ...

African Journals Online (AJOL)

The purpose of this study was to investigate the photocatalytic oxidation of a reactive azo dye and determine the improvement in the biodegradability when photocatalytic oxidation was used as a pretreatment step prior to biological treatment. The results obtained from the experiments adding H2O2/TiO2 show that the ...

Photosensitized Oxidation of 9,10-Dimethylanthracene on Dye-Doped Silica Composites

Directory of Open Access Journals (Sweden)

Elim Albiter

2012-01-01

Full Text Available A series of cationic dyes, methylene blue (MB, safranin O (SF, toluidine blue (TB, and neutral red (NR, were successfully incorporated into a silica matrix by using ultrasound irradiation during the Stöber process. Several analyses were performed, including scanning dynamic light scattering (DLS, electron microscopy (SEM, nitrogen physisorption, FTIR spectroscopy, UV-vis, and diffuse reflectance spectroscopy. The entrapped dyes on silica were evaluated in singlet oxygen (1O2 generation under visible light irradiation, by means of the photosensitized oxidation of 9,10-dimethylanthracene (DMA. According to the results, the photocatalytic performance of the silica composites was improved, and the leakage of the dye from the particles was suppressed. Among these four different types of dye-doped silica composites, the SiO2-SF composite showed the most efficient delivery of 1O2.

Patch testing with hair cosmetic series in Europe

DEFF Research Database (Denmark)

Uter, Wolfgang; Bensefa-Colas, Lynda; Frosch, Peter

2015-01-01

Many key ingredients of hair cosmetics (in particular, dyes, bleaches, and hair-styling agents) are potent (strong to extreme) contact allergens. Some heterogeneity is apparent from published results concerning the range of allergens for which patch testing is important. The objective...... of the present review was to collect information on the current practice of using 'hair cosmetic series', and discuss this against the background of evidence concerning consumer/professional exposure and regulatory aspects to finally derive a recommendation for a 'European hair cosmetic series'. The methods...... (Annex II of the Cosmetics Regulation). An up-to-date 'European hair cosmetics series', as recommended in the present article, should (i) include broadly used and/or potent contact allergens, (ii) eliminate substances of only historical concern, and (iii) be continually updated as new evidence emerges....

Analysis of in vivo penetration of textile dyes causing allergic reactions

International Nuclear Information System (INIS)

Lademann, J; Patzelt, A; Worm, M; Richter, H; Sterry, W; Meinke, M

2009-01-01

Contact allergies to textile dyes are common and can cause severe eczema. In the present study, we investigated the penetration of a fluorescent textile dye, dissolved from a black pullover, into the skin of one volunteer during perspiration and nonperspiration. Previously, wearing this pullover had induced a severe contact dermatitis in an 82-year old woman, who was not aware of her sensitization to textile dyes. The investigations were carried out by in vivo laser scanning microscopy. It could be demonstrated that the dye was eluted from the textile material by sweat. Afterwards, the dye penetrated into the stratum corneum and into the hair follicles. Inside the hair follicles, the fluorescent signal was still detectable after 24 h, whereas it was not verifiable anymore in the stratum corneum, Laser scanning microscopy represents an efficient tool for in vivo investigation of the penetration and storage of topically applied substances and allergens into the human skin and reveals useful hints for the development and optimization of protection strategies

Synthesis, Characterization, and Use of Novel Bimetal Oxide Catalyst for Photoassisted Degradation of Malachite Green Dye

Directory of Open Access Journals (Sweden)

K. L. Ameta

2014-01-01

Full Text Available This work reports a simple, novel, and cost effective synthesis of nanobimetal oxide catalyst using cerium and cadmium nitrates as metal precursors. The cerium-cadmium oxide nanophotocatalyst was synthesized by coprecipitation method and characterized by X-ray powder diffraction method to analyze the particle size. XRD study reveals a high degree of crystallinity and 28.43 nm particle size. The photocatalytic efficiency of the synthesized nanobimetal catalyst was examined by using it for the photocatalytic degradation of malachite green dye. Experiments were conducted to study the effect of various parameters, such as the pH of the dye solution, concentration of dye, amount of catalyst, and light intensity on the rate of dye degradation. The progress of the dye degradation was monitored spectrophotometrically by taking the optical density of the dye solution at regular intervals. Experimental results indicate that the dye degrades best at pH 8.0 with light intensity 600 Wm−2 and catalyst loading 0.03 g/50 mL of dye solution. The rate constant for the reaction was 7.67 × 10−4 s−1.

Tailoring oxides of copper-Cu_2O and CuO nanoparticles and evaluation of organic dyes degradation

International Nuclear Information System (INIS)

Raghav, Ragini; Aggarwal, Priyanka; Srivastava, Sudha

2016-01-01

We report a simple one-pot colloidal synthesis strategy tailoring cuprous or cupric nano-oxides in pure state. NaOH provided alkaline conditions (pH 12.5 -13) for nano-oxides formation, while its concentration regulated the oxidation state of the nano-oxides. The morphological, structural and optical properties of synthesized Cu_2O and CuO nanoparticles were studied by transmission electron microscopy (TEM), X-Ray diffraction (XRD) and UV-vis spectroscopy. Dye degradation capability of CuO and Cu2O nanoparticles was evaluated using four organic dyes - Malachite green, Methylene blue, Methyl orange and Methyl red. The results demonstrate effective degradation of all four dyes employing with almost comparable activity both Cu_2O and CuO nanoparticles.

Optical study of planar waveguides based on oxidized porous silicon impregnated with laser dyes

Energy Technology Data Exchange (ETDEWEB)

Chouket, A. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia); Charrier, J. [Laboratoire d' Optronique CNRS-UMR FOTON 6082, Universite de Rennes 1, ENSSAT-6 rue de Kerampont, BP 80518, 22305 Lannion Cedex (France); Elhouichet, H. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia)], E-mail: habib.elhouichet@fst.rnu.tn; Oueslati, M. [Unite de recherche de Spectroscopie Raman, Departement de Physique, Faculte des Sciences de Tunis, Elmanar 2092, Tunis (Tunisia)

2009-05-15

Oxidized porous silicon optical planar waveguides were elaborated and impregnated with rhodamine B and rhodamine 6G. The waveguiding, absorption, and photoluminescence properties of these impregnated waveguides were studied. Successful impregnation of the structure with laser dyes is shown from photoluminescence and reflectivity measurements. Furthermore, the reflectivity spectra prove the homogenous incorporation of both dye molecules inside the pores of the matrices. The refractive indices of waveguide layers were determined before and after dye impregnation to indicate the conservation of guiding conditions. The optical losses in the visible wavelengths are studied as a function of dye concentration. The dye absorption is the main reason for these losses.

Reverse Engineering Applied to Red Human Hair Pheomelanin Reveals Redox-Buffering as a Pro-Oxidant Mechanism

Science.gov (United States)

Kim, Eunkyoung; Panzella, Lucia; Micillo, Raffaella; Bentley, William E.; Napolitano, Alessandra; Payne, Gregory F.

2015-01-01

Pheomelanin has been implicated in the increased susceptibility to UV-induced melanoma for people with light skin and red hair. Recent studies identified a UV-independent pathway to melanoma carcinogenesis and implicated pheomelanin’s pro-oxidant properties that act through the generation of reactive oxygen species and/or the depletion of cellular antioxidants. Here, we applied an electrochemically-based reverse engineering methodology to compare the redox properties of human hair pheomelanin with model synthetic pigments and natural eumelanin. This methodology exposes the insoluble melanin samples to complex potential (voltage) inputs and measures output response characteristics to assess redox activities. The results demonstrate that both eumelanin and pheomelanin are redox-active, they can rapidly (sec-min) and repeatedly redox-cycle between oxidized and reduced states, and pheomelanin possesses a more oxidative redox potential. This study suggests that pheomelanin’s redox-based pro-oxidant activity may contribute to sustaining a chronic oxidative stress condition through a redox-buffering mechanism. PMID:26669666

Electro-oxidation of the dye azure B: kinetics, mechanism, and by-products.

Science.gov (United States)

Olvera-Vargas, Hugo; Oturan, Nihal; Aravindakumar, C T; Paul, M M Sunil; Sharma, Virender K; Oturan, Mehmet A

2014-01-01

In this work, the electrochemical degradation of the dye azure B in aqueous solutions was studied by electrochemical advanced oxidation processes (EAOPs), electro-Fenton, and anodic oxidation processes, using Pt/carbon-felt and boron-doped diamond (BDD)/carbon-felt cells with H₂O₂ electrogeneration. The higher oxidation power of the electro-Fenton (EF) process using BDD anode was demonstrated. The oxidative degradation of azure B by the electrochemically generated hydroxyl radicals ((•)OH) follows a pseudo-first-order kinetics. The apparent rate constants of the oxidation of azure B by (•)OH were measured according to pseudo-first-order kinetic model. The absolute rate constant of azure B hydroxylation reaction was determined by competition kinetics method and found to be 1.19 × 10(9) M(-1) s(-1). It was found that the electrochemical degradation of the dye leads to the formation of aromatic by-products which are then oxidized to aliphatic carboxylic acids before their almost mineralization to CO₂ and inorganic ions (sulfate, nitrate, and ammonium). The evolution of the TOC removal and time course of short-chain carboxylic acids during treatment were also investigated.

HSL Attenuates the Follicular Oxidative Stress and Enhances the Hair Growth in ob/ob Mice

Directory of Open Access Journals (Sweden)

Takeo Minematsu, PhD

2013-10-01

Full Text Available Summary: We demonstrated enhanced hair regeneration following topical administration of N-(3-oxododecanoyl-L-homoserine lactone (HSL in ob/ob mice. The ob/ob mice showed delayed hair regeneration (more than 6 wk after depilation, which rapidly induced transition to anagen in the hair cycle in wild-type mice. Vehicle and HSL solutions were applied to the depilated dorsal skin of ob/ob mice. The depilated skin of the HSL-treated mice was fully covered with hair, whereas no macroscopic alteration was observed in vehicle-treated group by the fourth week after depilation. Oxidative stress was drastically decreased and the expression of the antioxidative enzymes PON1 and PON3 was increased in the HSL-treated skin with highly proliferative anagen follicles. These results suggest that HSL is a candidate therapeutic agent for alopecia in metabolic syndrome.

The effect of the textile industry dye bath additive EDTMPA on colour removal characteristics by ozone oxidation.

Science.gov (United States)

Olmez, T; Kabdaşli, I; Tünay, O

2007-01-01

In this study, the effects of the phosphonic acid based sequestering agent EDTMPA used in the textile dye baths on colour and organic matter removal by ozone oxidation was experimentally investigated. Procion Navy HEXL dyestuff that has been commonly used for the reactive dyeing of cellulose fibers was selected as the model component. The organic matter oxidation by ozone was determined to obey the pseudo-first order kinetics as they are treated singly or in combination. COD removal rates obtained from pseudo-first order reaction kinetics showed that oxidation of Navy HEXL alone (0.0947 L/min) was faster than that of EDTMPA (0.0171 L/min) and EDTMPA with dye (0.0155 L/min) at pH 3.0. It was also found that reaction rates of single EDTMPA removal and EDTMPA and dye mixture removal increased as the reaction pH was increased from 3.0 to 10.5.

Mineralization and biodegradability enhancement of Methyl Orange dye by an effective advanced oxidation process

International Nuclear Information System (INIS)

Paul Guin, Jhimli; Bhardwaj, Y.K.; Varshney, Lalit

2017-01-01

An effective process for the oxidation of Methyl Orange dye (MO) was determined by comparing the mineralization efficiency between two advanced oxidation processes (AOPs) viz., ozonolysis and gamma radiolysis in presence and absence of an added inorganic salt potassium persulfate (K_2S_2O_8). The effects of various operating parameters such as ozone flow rate and reaction temperature were optimized to achieve the best possible mineralization extent of MO by ozonolysis. The mineralization efficiency of MO was significantly enhanced during gamma radiolysis in presence of K_2S_2O_8 (γ+K_2S_2O_8) compared to in absence of K_2S_2O_8. The presence of methyl group at the amine of phenyl ring assisted the mineralization of dye during γ+K_2S_2O_8. The oxygen-equivalent chemical-oxidation capacities (OCC) of ozonolysis and γ+K_2S_2O_8 for 75% mineralization of the dye solution were calculated as 7.008 and 0.0336 kg equiv. O_2 m"−"3, respectively which signifies that γ+K_2S_2O_8 can be explored as an effective AOP. The non-biodegradable MO dye solution became biodegradable even after the dose of 0.5 kGy during γ+K_2S_2O_8 compared to 1 kGy in absence of K_2S_2O_8. The study concludes that a lower dose γ+K_2S_2O_8 could be one of the efficient pretreatment steps before undergoing biological degradation of dye solution. - Highlights: • Systematic investigation was performed for the treatment of Methyl Orange dye solution. • AOPs investigated were ozonolysis and gamma radiolysis. • The OCC and % mineralizations of the AOPs were compared. • Gamma radiolysis in presence of K_2S_2O_8 was found as most effective AOP.

On the degradability of printing and dyeing wastewater by wet air oxidation.

Science.gov (United States)

Hu, X; Lei, L; Chen, G; Yue, P L

2001-06-01

A modified first-order kinetics model was used to study the wet air oxidation of printing and dyeing wastewater. The model simulations are in good agreement with experimental data. The results indicate that a certain fraction of organic pollutants in the printing and dyeing wastewater could not be removed even at elevated temperature and prolonged reaction time. The ratio of degradable organic matter is found independent of temperature and can be improved by using a catalyst.

Rapid and tunable selective adsorption of dyes using thermally oxidized nanodiamond.

Science.gov (United States)

Molavi, Hossein; Shojaei, Akbar; Pourghaderi, Alireza

2018-03-27

In the present study, capability of nanodiamond (ND) for the adsorption of anionic (methyl orange, MO) and cationic (methylene blue, MB) dyes from aqueous solution was investigated. Employing fourier transform infrared (FTIR) spectroscopy, Boehm titration method and zeta potential, it was found that the simple thermal oxidation of ND at 425 °C, increased the content of carboxylic acid of ND and accordingly the zeta potential of ND decreased considerably. Therefore, a series of oxidized NDs (OND) at various oxidation times and as-received untreated ND (UND) was used as adsorbents of MO and MB. The adsorption experiments exhibited that UND had large adsorption capacity, very fast adsorption kinetics and excellent selectivity for MO over MB. These results suggested that the adsorption tendency of UND toward anionic MO dye followed not only by electrostatic interactions but also via the chemical interaction caused by the strong hydrogen bond between the sulfonate groups of MO and the oxygen containing groups on the surface of UND. In contrast, ONDs exhibited higher adsorption capacity for cationic MB whose tendency toward MB increased by increasing the thermal oxidation time due to the promotion of the negative charge on the surface of OND leading to the higher electrostatic attraction. The adsorption rate of MB on ONDs was also very high. Kinetics data was well fitted with the pseudo- second-order model for most of the adsorbents. The adsorption selectivity analysis revealed that ONDs displayed more adsorption capacity for MB compared with MO which was also attributed to high electrostatic interactions of cationic dye with negative charges of ONDs. Finally, the release behavior of NDs was also demonstrated after soaking in ethanol and acetone. Copyright © 2018 Elsevier Inc. All rights reserved.

Synthesis of oxidized guar gum by dry method and its application in reactive dye printing.

Science.gov (United States)

Gong, Honghong; Liu, Mingzhu; Zhang, Bing; Cui, Dapeng; Gao, Chunmei; Ni, Boli; Chen, Jiucun

2011-12-01

The aim of this study was to prepare oxidized guar gum with a simple dry method, basing on guar gum, hydrogen peroxide and a small amount of solvent. To obtain a product with suitable viscosity for reactive dye printing, the effects of various factors such as the amount of oxidant and solvent, reaction temperature and time were studied with respect to the viscosity of reaction products. The product was characterized by Fourier transform infrared spectroscopy, size exclusion chromatography, scanning electron microscopy and differential scanning calorimetry. The hydrated rate of guar gum and oxidized guar gum was estimated through measuring the required time when their solutions (1%, w/v) reached the maximum viscosity. The effects of the salt concentration and pH on viscosity of the resultant product were studied. The mixed paste containing oxidized guar gum and carboxymethyl starch was prepared and its viscosity was determined by the viscometer. The rheological property of the mixed paste was appraised by the printing viscosity index. In addition, the applied effect of mixed paste in reactive dye printing was examined by assessing the fabric stiffness, color yield and sharp edge to the printed image in comparison with sodium alginate. And the results indicated that the mixed paste could partially replace sodium alginate as thickener in reactive dye printing. The study also showed that the method was low cost and eco-friendly and the product would have an extensive application in reactive dye printing. Copyright © 2011 Elsevier B.V. All rights reserved.

Azo dyes degradation using TiO2-Pt/graphene oxide and TiO2-Pt/reduced graphene oxide photocatalysts under UV and natural sunlight irradiation

Science.gov (United States)

Rosu, Marcela-Corina; Coros, Maria; Pogacean, Florina; Magerusan, Lidia; Socaci, Crina; Turza, Alexandru; Pruneanu, Stela

2017-08-01

The photocatalytic degradation of azo dyes with different structures (amaranth, sunset yellow and tartrazine) using TiO2-Pt nanoparticles (TPt), TiO2-Pt/graphene oxide (TPt-GO) and TiO2-Pt/reduced graphene oxide (TPt-rGO) composites were investigated in the presence of UV and natural sunlight irradiation. The composites were prepared by a combined chemical-thermal method and characterized by Transmission Electron Microscopy (TEM), X-ray powder diffraction (XRD), Infrared (FTIR) and UV-Vis spectroscopy. The modification of TiO2-Pt with graphene oxide shifted its optical absorption edge towards the visible region and increased its photocatalytic activity under UV and natural sunlight irradiation. The efficiency of catalysts on azo dyes degradation (in similar conditions) reached high values (above 99%) under sunlight conditions, proving the remarkable photocatalytic activities of obtained composites. TPt-GO nanocomposite exhibited higher photoactivity than TPt or TPt-rGO, demonstrating degradation efficiencies of 99.56% for amaranth, 99.15% for sunset yellow and 96.23% for tartrazine. The dye photodegradation process follows a pseudo-first-order kinetic with respect to the Langmuir-Hinshelwood reaction mechanism. A direct dependence between azo dyes degradation rate and chemical structure of dyes has been observed.

Fenton oxidative decolorization of the azo dye Direct Blue 15 in aqueous solution

DEFF Research Database (Denmark)

Sun, Jian-Hui; Shi, Shao-Hui; Lee, Yi-Fan

2009-01-01

In this paper, the application of Fenton oxidation process for the decolorization of an azo dye Direct Blue 15 (DB15) in aqueous solution was investigated. The effect of initial pH, dosage of H2O2, H2O2/Fe2+ and H2O2/dye ratios and the reaction temperature on the decolorization efficiency...... = 60: 1 and temperature = 30 degrees C. Under the optimal conditions, 4.7 x 10(-5) mol/L of the DB15 aqueous solution can be completely decolorized by Fenton oxidation within 50-min reaction time and the decolorization kinetic rate constant k was determined as 0.1694 min(-1). Additionally increasing...... the reaction temperature from 20 to 40 degrees C showed a positive effect on the decolorization efficiency of DB15. The present study can provide guidance to relational industry operators and planners to effectively treat the DB15 contaminated wastewater by Fenton oxidation process. (C) 2009 Elsevier B. V. All...

A Dye-Sensitized Solar Cell Using a Composite of PEDOT:PSS and Carbon Derived from Human Hair for a Counter Electrode

Directory of Open Access Journals (Sweden)

Klitsada Moolsarn

2017-01-01

Full Text Available Carbon derived from hair is interesting because it has good electrocatalytic activity due to the existence of innate heteroatom dopants especially nitrogen and sulfur. In this study, a carbon catalyst containing high nitrogen contents (9.47 at.% was fabricated without using any harsh chemicals. Moreover, the carbonization temperature was only 700°C. Carbonized hair/PEDOT:PSS composites (CxP with varied carbon contents from x = 0.2 to 0.8 g were tested as a counter electrode (CE for a dye-sensitized solar cell (DSSC. This type of DSSC CE has scarcely been investigated. A DSSC with a C0.6P CE provides the best efficiency (6.54 ± 0.11% among all composite CEs because it has a high fill factor (FF and a high short-circuit current density (Jsc. The efficiency of DSSC with C0.6P CE is lower than Pt’s (7.29 ± 0.01% since the Pt-based DSSC has higher FF and Jsc values. However, C0.6P is still promising as a DSSC CE since it is more cost-effective than Pt.

Elaboration of nano titania-magnetic reduced graphene oxide for degradation of tartrazine dye in aqueous solution

Science.gov (United States)

Nada, Amr A.; Tantawy, Hesham R.; Elsayed, Mohamed A.; Bechelany, Mikhael; Elmowafy, Mohamed E.

2018-04-01

In this paper, magnetic nanocomposites are synthesized by loading reduced graphene oxide (RG) with two components of nanoparticles consisting of titanium dioxide (TiO2) and magnetite (Fe3O4) with varying amounts. The structural and magnetic features of the prepared composite photocatalysts were investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (UV-vis/DRS), Raman and vibrating sample magnetometer (VSM). The resulting TiO2/magnetite reduced graphene oxide (MRGT) composite demonstrated intrinsic visible light photocatalytic activity, on degradation of tartrazine (TZ) dye from a synthetic aqueous solution. Specifically, it exhibits higher photocatalytic activity than magnetite reduced graphene oxide (MRG) and TiO2 nanoparticles. The photocatalytic degradation of TZ dye when using MRG and TiO2 for 3 h under visible light was 35% and 10% respectively, whereas for MRGT it was more than 95%. The higher photocatalytic efficiency of MRGT is due to the existence of reduced graphene oxide and magnetite which enhances the photocatalytic efficiency of the composite in visible light towards the degradation of harmful soluble azo dye (tartrazine).

Preparation of Biocolorant and Eco-Dyeing Derived from Polyphenols Based on Laccase-Catalyzed Oxidative Polymerization

Directory of Open Access Journals (Sweden)

Fubang Wang

2018-02-01

Full Text Available Natural products have been believed to be a promising source to obtain ecological dyes and pigments. Plant polyphenol is a kind of significant natural compound, and tea provides a rich source of polyphenols. In this study, biocolorant derived from phenolic compounds was generated based on laccase-catalyzed oxidative polymerization, and eco-dyeing of silk and wool fabrics with pigments derived from tea was investigated under the influence of pH variation. This work demonstrated that the dyeing property was better under acidic conditions compared to alkalinity, and fixation rate was the best when pH value was 3. Furthermore, breaking strength of dyed fabrics sharply reduced under the condition of pH 11. Eventually, the dyeing method was an eco-friendly process, which was based on bioconversion, and no mordant was added during the process of dyeing.

The performance and decolourization kinetics of O3/H2O2 oxidation of reactive green 19 dye in wastewater

Science.gov (United States)

Sabri, S. N.; Abidin, C. Z. A.; Fahmi; Kow, S. H.; Razali, N. A.

2018-03-01

The degradations characteristic of azo dye Reactive Green 19 (RG19) was investigated using advanced oxidation process (AOPs). It was evaluated based on colour and chemical oxygen demand (COD) removal. The effect of operational parameters such as initial dye concentration, initial dosage of hydrogen peroxide (H2O2), contact time, and pH was also being studied. The samples were treated by ozonation (O3) and peroxone O3/H2O2 process. Advanced oxidation processes (AOPs) involve two stages of oxidation; firstly is the formation of strong oxidant and secondly the reaction of organic contaminants in water. In addition, the term advanced oxidation is referring to the processes in which oxidation of organic contaminants occurs primarily through reactions with hydroxyl radicals. There are several analyses that use to determine the efficiency of the treatment process, which are UV-Vis absorption spectra, COD, Fourier Transform Infrared (FT-IR), and pH. The results demonstrated that the ozone oxidation was efficient in decolourization and good in mineralization, based on the reduction of colour and COD. Additionally, results indicate that H2O2 is able to perform better than ozonation in order to decolourize the dye wastewater with 0.5 mL H2O2/L dye dosage of H2O2 at different initial concentration, initial pH, with contact time.

A simple method for purification of vestibular hair cells and non-sensory cells, and application for proteomic analysis.

Science.gov (United States)

Herget, Meike; Scheibinger, Mirko; Guo, Zhaohua; Jan, Taha A; Adams, Christopher M; Cheng, Alan G; Heller, Stefan

2013-01-01

Mechanosensitive hair cells and supporting cells comprise the sensory epithelia of the inner ear. The paucity of both cell types has hampered molecular and cell biological studies, which often require large quantities of purified cells. Here, we report a strategy allowing the enrichment of relatively pure populations of vestibular hair cells and non-sensory cells including supporting cells. We utilized specific uptake of fluorescent styryl dyes for labeling of hair cells. Enzymatic isolation and flow cytometry was used to generate pure populations of sensory hair cells and non-sensory cells. We applied mass spectrometry to perform a qualitative high-resolution analysis of the proteomic makeup of both the hair cell and non-sensory cell populations. Our conservative analysis identified more than 600 proteins with a false discovery rate of Analysis of proteins exclusively detected in either population revealed 64 proteins that were specific to hair cells and 103 proteins that were only detectable in non-sensory cells. Statistical analyses extended these groups by 53 proteins that are strongly upregulated in hair cells versus non-sensory cells and vice versa by 68 proteins. Our results demonstrate that enzymatic dissociation of styryl dye-labeled sensory hair cells and non-sensory cells is a valid method to generate pure enough cell populations for flow cytometry and subsequent molecular analyses.

Fibrous flexible solid-type dye-sensitized solar cells without transparent conducting oxide

International Nuclear Information System (INIS)

Fan Xing; Chu Zengze; Chen Lin; Zhang Chao; Wang Fuzhi; Tang Yanwei; Sun Jianliang; Zou Dechun

2008-01-01

We have explored a type of all-solid fibrous flexible dye-sensitized solar cells without transparent conducting oxide based on a CuI electrolyte. The working electrode's substrate is a metal wire. Cu wire counterelectrode is twisted with the dye-sensitized and CuI-coated working electrode. The cell's apparent diameter is about 150 μm. The cell's current-voltage output depends little on the incident angle of light. A 4-cm-long fibrous cell's open-circuit voltage and short-circuit current generate 304 mV and 0.032 mA, respectively. The interfacial interaction between the two electrodes has a significant influence on the inner charge transfer of the cell

Analytical investigations of toxic p-phenylenediamine (PPD) levels in clinical urine samples with special focus on MALDI-MS/MS

NARCIS (Netherlands)

G.P. Hooff (Gero); N.A. van Huizen (Nick); R.J.W. Meesters (Roland); E. Zijlstra (Ed); M. Abdelraheem (Mohamed); M. Hamdouk (Mohamed); J. Lindemans (Jan); T.M. Luider (Theo)

2011-01-01

textabstractPara-phenylenediamine (PPD) is a common chromophoric ingredient in oxidative hair-dyes. In some African countries like Sudan, Egypt and Morocco but also in India this chemical is used alone or in combination with colouring extracts like Henna for dyeing of the hair or the skin. Excessive

Hyposmotic stimulation-induced nitric oxide production in outer hair cells of the guinea pig cochlea.

Science.gov (United States)

Takeda-Nakazawa, Hiroko; Harada, Narinobu; Shen, Jing; Kubo, Nobuo; Zenner, Hans-Peter; Yamashita, Toshio

2007-08-01

Nitric oxide (NO) production during hyposmotic stimulation in outer hair cells (OHCs) of the guinea pig cochlea was investigated using the NO sensitive dye DAF-2. Simultaneous measurement of the cell length and NO production showed rapid hyposmotic-induced cell swelling to precede NO production in OHCs. Hyposmotic stimulation failed to induce NO production in the Ca2+-free solution. L-NG-nitroarginine methyl ester (L-NAME), a non-specific NO synthase inhibitor and gadolinium, a stretch-activated channel blocker inhibited the hyposmotic stimulation-induced NO production whereas suramin, a P2 receptor antagonist did not. S-nitroso-N-acetylpenicillamine (SNAP), a NO donor inhibited the hyposmotic stimulation-induced increase in the intracellular Ca2+ concentrations ([Ca2+]i) while L-NAME enhanced it. 1H-[1,2,4]oxadiazole[4,3a]quinoxalin-1-one, an inhibitor of guanylate cyclase and KT5823, an inhibitor of cGMP-dependent protein kinase (PKG) mimicked effects of L-NAME on the Ca2+ response. Transient receptor potential vanilloid 4 (TRPV4), an osmo- and mechanosensitive channel was expressed in the OHCs by means of immunohistochemistry. 4alpha-phorbol 12,13-didecanoate, a TRPV4 synthetic activator, induced NO production in OHCs. These results suggest that hyposmotic stimulation can induce NO production by the [Ca2+]i increase, which is presumably mediated by the activation of TRPV4 in OHCs. NO conversely inhibits the Ca2+ response via the NO-cGMP-PKG pathway by a feedback mechanism.

Application of Ni-Oxide@TiO₂ Core-Shell Structures to Photocatalytic Mixed Dye Degradation, CO Oxidation, and Supercapacitors.

Science.gov (United States)

Lee, Seungwon; Lee, Jisuk; Nam, Kyusuk; Shin, Weon Gyu; Sohn, Youngku

2016-12-20

Performing diverse application tests on synthesized metal oxides is critical for identifying suitable application areas based on the material performances. In the present study, Ni-oxide@TiO₂ core-shell materials were synthesized and applied to photocatalytic mixed dye (methyl orange + rhodamine + methylene blue) degradation under ultraviolet (UV) and visible lights, CO oxidation, and supercapacitors. Their physicochemical properties were examined by field-emission scanning electron microscopy, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, and UV-visible absorption spectroscopy. It was shown that their performances were highly dependent on the morphology, thermal treatment procedure, and TiO₂ overlayer coating.

Electronic structure of the indium tin oxide/nanocrystalline anatase (TiO2)/ruthenium-dye interfaces in dye-sensitized solar cells

Science.gov (United States)

Lyon, J. E.; Rayan, M. K.; Beerbom, M. M.; Schlaf, R.

2008-10-01

The electronic structure of two interfaces commonly found in dye-sensitized photovoltaic cells based on nanocrystalline anatase TiO2 ("Grätzel cells") was investigated using photoemission spectroscopy (PES). X-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) measurements were carried out on the indium tin oxide (ITO)/TiO2 and the TiO2/cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)-ruthenium(II)bis-tetrabutylammonium dye ("N719" or "Ruthenium 535-bisTBA") interfaces. Both contacts were investigated using a multistep deposition procedure where the entire structure was prepared in vacuum using electrospray deposition. In between deposition steps the surface was characterized with XPS and UPS resulting in a series of spectra, allowing the determination of the orbital and band lineup at the interfaces. The results of these efforts confirm previous PES measurements on TiO2/dye contacts prepared under ambient conditions, suggesting that ambient contamination might not have significant influence on the electronic structure at the dye/TiO2 interface. The results also demonstrate that there may be a significant barrier for electron injection at the sputtered ITO/TiO2 interface and that this interface should be viewed as a semiconductor heterojunction rather than as metal-semiconductor (Schottky) contact.

Two-Sided Surface Oxidized Cellulose Membranes Modified with PEI: Preparation, Characterization and Application for Dyes Removal

Directory of Open Access Journals (Sweden)

Wei Wang

2017-09-01

Full Text Available Porous regenerated cellulose (RC membranes were prepared with cotton linter pulp as a raw material. These membranes were first oxidized on both sides by a modified (2,2,6,6-tetramethylpiperidin-1-yloxyl (TEMPO oxidation system using a controlled oxidation reaction technique. Then, the oxidized RC membranes were functionalized with polyethylenimine (PEI via the glutaraldehyde crosslinking method to obtain bifunctional (carboxyl and amino porous RC membranes, as revealed by Fourier transform infrared spectroscopy (FT-IR, elemental analysis and zeta potential measurement. The scanning electron microscopy (SEM and the tests of the mechanical properties and permeability characteristics of modified RC membranes demonstrated that the porous structure and certain mechanical properties could be retained. The adsorption performance of the modified membranes towards dyes was subsequently investigated. The modified membranes displayed good adsorption capacities, rapid adsorption equilibrium and removal efficiencies towards both anionic (xylenol orange (XO and cationic (methylene blue (MB dyes, making them suitable bioadsorbents for wastewater treatment.

Toxicity Reduction of Reactive Red Dye-238 Using Advanced Oxidation Process by Solar Energy

Directory of Open Access Journals (Sweden)

Riyad Al-Anbari

2017-09-01

Full Text Available Decolorization of red azo dye (Cibacron Red FN-R from synthetic wastewater has been investigated as a function of solar advanced oxidation process. The photocatalytic activity using ZnO as a photocatalysis has been estimated. Different parameters affected the removal efficiency, including pH of the solution, initial dye concentration and H2O2 concentration were evaluated to find out the optimum value of these parameters. The results proved that the optimal pH value was 8 and the most efficient H2O2 concentration was 100mg/L. Toxicity reduction percent for effluent solution was also monitored to assess the degradation process. This treatment method was able to strongly reduce the color and toxicity of reactive red dye-238 to about (99 and 80 % respectively. It can be concluded, from these experiments, that the using of ZnO as a photocatalysis was exhibited as economical and efficient treatment method to remove reactive red dye-238 from aqueous solution.

Experimental Study on Treatment of Dyeing Wastewater by Activated Carbon Adsorption, Coagulation and Fenton Oxidation

Science.gov (United States)

Xiaoxu, SUN; Jin, XU; Xingyu, LI

2017-12-01

In this paper dyeing waste water was simulated by reactive brilliant blue XBR, activated carbon adsorption process, coagulation process and chemical oxidation process were used to treat dyeing waste water. In activated carbon adsorption process and coagulation process, the water absorbance values were measured. The CODcr value of water was determined in Fenton chemical oxidation process. Then, the decolorization rate and COD removal rate were calculated respectively. The results showed that the optimum conditions of activated carbon adsorption process were as follows: pH=2, the dosage of activated carbon was 1.2g/L, the adsorption reaction time was 60 min, and the average decolorization rate of the three parallel experiments was 85.30%. The optimum conditions of coagulation experiment were as follows: pH=8~9, PAC dosage was 70mg/L, stirring time was 20min, standing time was 45min, the average decolorization rate of the three parallel experiments was 74.48%. The optimum conditions for Fenton oxidation were Fe2+ 0.05g/L, H2O2 (30%) 14mL/L, pH=3, reaction time 40min. The average CODcr removal rate was 69.35% in three parallel experiments. It can be seen that in the three methods the activated carbon adsorption treatment of dyeing wastewater was the best one.

Dye-Sensitized Solar Cells Based on High Surface Area Nanocrystalline Zinc Oxide Spheres

Directory of Open Access Journals (Sweden)

Pavuluri Srinivasu

2011-01-01

Full Text Available High surface area nanocrystalline zinc oxide material is fabricated using mesoporous nanostructured carbon as a sacrificial template through combustion process. The resulting material is characterized by XRD, N2 adsorption, HR-SEM, and HR-TEM. The nitrogen adsorption measurement indicates that the materials possess BET specific surface area ca. 30 m2/g. Electron microscopy images prove that the zinc oxide spheres possess particle size in the range of 0.12 μm–0.17 μm. The nanocrystalline zinc oxide spheres show 1.0% of energy conversion efficiency for dye-sensitized solar cells.

Optically Transparent Cathode for Co(III/II) Mediated Dye-Sensitized Solar Cells Based on Graphene Oxide

Czech Academy of Sciences Publication Activity Database

Kavan, Ladislav; Yum, J. H.; Graetzel, M.

2012-01-01

Roč. 4, č. 12 (2012), s. 6998-7005 ISSN 1944-8244 R&D Projects: GA AV ČR IAA400400804; GA AV ČR KAN200100801 Institutional support: RVO:61388955 Keywords : graphene oxide * reduced graphene oxide * dye-sensitized solar cell Subject RIV: CG - Electrochemistry Impact factor: 5.008, year: 2012

Selective hair therapy: bringing science to the fiction.

Science.gov (United States)

Vogt, Annika; Blume-Peytavi, Ulrike

2014-02-01

Investigations on carrier-based drug delivery systems for higher selectivity in hair therapy have clearly evolved from dye release and model studies to highly sophisticated approaches, many of which specifically tackle hair indications and the delivery of hair-relevant molecules. Here, we group recent hair disease-oriented work into efforts towards (i) improved delivery of conventional drugs, (ii) delivery of novel drug classes, for example biomolecules and (iii) targeted delivery on the cellular/molecular level. Considering the solid foundation of experimental work, it does not take a large step outside the current box of thinking to follow the idea of using large carriers (>500 nm, unlikely to penetrate as a whole) for follicular penetration, retention and protection of sensitive compounds. Yet, reports on particles <200 nm being internalized by keratinocytes and dendritic cells at sites of barrier disruption (e.g., hair follicles) combined with recent advances in nanodermatology add interesting new facets to the possibilities carrier technologies could offer, for example, unprecedented levels of selectivity. The authors provide thought-provoking ideas on how smart delivery technologies and advances in our molecular understanding of hair pathophysiology could result in a whole new era of hair therapeutics. As the field still largely remains in preclinical investigation, determined efforts towards production of medical grade material and truly translational work are needed to demonstrate surplus value of carrier systems for clinical applications. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

UV/Fenton photo-oxidation of Drimarene Dark Red (DDR) containing textile-dye wastewater

Science.gov (United States)

Hudaya, T.; Anthonios, J.; Septianto, E.

2016-11-01

Textile dye wastewater contains organic pollutants which are non-biodegradable, characterized by low BOD/COD ratio of typically Advanced Oxidation Processes (AOPs). One of the AOPs method which is the UV/H2O2/Fe2+ (or UV/Fenton) offers not only relatively low cost but also quite effective (in terms of color removal and reaction time) treatment. This particular research aimed to optimize the conditions of UV/Fenton photo-oxidation process for Drimarene Dark Red containing textile- dye wastewater. The two main operating conditions to be optimized were the initial concentration of H2O2 ranged between 0.022-0.078 %-w and the mol ratio of Fe2+: H2O2 was varied from 1: 13 up to 1: 45, using the Central Composite Design experimental matrix. The photo-oxidation was carried out at the optimum pH of 3 from some previous experiments. The best processing conditions of the photo-oxidation of Drimarene Dark Red (DDR) were found at the initial concentration of H2O2 at 0.050%-w and the mole ratio Fe2+: H2O2 of 1: 22. Under these conditions, the measured 2nd order pseudo-rate constantwas 0.021 M-1.min-1. The DDR color removal of 90% was surprisingly achievable within only 10 minutes reaction time.

Morphology dependent dye-sensitized solar cell properties of nanocrystalline zinc oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Sharma, S.K., E-mail: sanjeevlrs732000@yahoo.co.in [Department of Information and Communication, Cheju Halla College, Jeju City 690 708 (Korea, Republic of); Inamdar, A.I.; Im, Hyunsik [Department of Semiconductor Science, Dongguk University, Seoul 100 715 (Korea, Republic of); Kim, B.G. [Department of Information and Communication, Cheju Halla College, Jeju City 690 708 (Korea, Republic of); Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India)

2011-02-03

Research highlights: > Nano-crystalline zinc oxide thin films were electrosynthesized from an aqueous zinc acetate [Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O] solution onto FTO coated conducting glass substrates using two different electrochemical routes, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) or SDS (sodium dodecyl sulfate). > The reproducibility of the catalytic activity of the SDS and PVA surfactants in the modification of the morphologies was observed. > Vertically aligned nest-like and compact structures were observed from the SDS and PVA mediated films, respectively, while the grain size in the ZnO thin films without an organic surfactant was observed to be {approx}150 nm. > The dye sensitized ZnO electrodes displayed excellent properties in the conversion process from light to electricity. The efficiencies of the surfactant mediated nanocrystalline ZnO thin films, viz. ZnO:SDS and ZnO:PVA, sensitized with ruthenium-II (N3) dye were observed to be 0.49% and 0.27%, respectively. - Abstract: Nano-crystalline zinc oxide thin films were electrosynthesized with an aqueous zinc acetate [Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O] solution on to FTO coated glass substrates. Two different electrochemical baths were used, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) and SDS (sodium dodecyl sulfate). The organic surfactants played an important role in modifying the surface morphology, which influenced the size of the crystallites and dye-sensitized solar cell (DSSC) properties. The vertically aligned thin and compact hexagonal crystallites were observed with SDS mediated films, while the grain size in the films without an organic surfactant was observed to be {approx}150 nm. The conversion efficiencies of the ZnO:SDS:Dye and ZnO:PVA:Dye thin films were observed to be 0.49% and 0.27%, respectively.

The impact of demographic factors, behaviors and environmental exposure to mercury content in the hair of the population living in the region of Lodz (central Poland).

Science.gov (United States)

Marcinek-Jacel, Marta; Albińska, Jadwiga; Pawlaczyk, Aleksandra; Szynkowska, Małgorzata Iwona

2017-10-01

The aim of this work was to access the influence of different factors such as sex, age, fish consumption, hair dyeing or smoking habit on the content of mercury in human hair samples. The research was carried on 444 samples (102 males and 342 females) collected from the population of people living in the region of Lodz (central Poland). The content of mercury in human hair samples was determined using the Mercury Analyzer MA 3000 (Nippon Instruments, Japan). The obtained results were elaborated using Statistica ver. 10.0 software. The mean value of mercury in investigated human hair samples was found to be 0.174±0.137mg/kg. We observed the statistically significant correlations (p<0.05) between the content of Hg in hair of the studied population and factors such as gender, age, and fish consumption. However, no statistically significant differences were found in relation to cosmetic treatment such as hair dyeing or smoking. Copyright © 2017 Elsevier B.V. All rights reserved.

Characteristics of dye Rhoeo spathacea in dye sensitizer solar cell (DSSC)

Science.gov (United States)

Sumardiasih, Sri; Obina, Wilfrida M.; Cari; Supriyanto, Agus; Septiawan, Trio Y.; Khairuddin

2017-01-01

Dye-sensitized solar cell (DSSC) is a device that converts solar energy into electrical energy. The magnitude of the efficiency of DSSC is mainly based on the amount of dye absorbed by the surface of TiO2. In this work, used natural dye extracted from leaves Rhoeo spathacea. The dye partially used to immerse of TiO2 as working electrodes, and the rest are directly mixed TiO2 paste to obtain dye titanium dioxide.The paste TiO2 and dye titanium dioxide coated onto the fluorine-doped tin oxide (FTO) glass plate by spin coating method. The absorbance spectra of the dye, dye titanium dioxide and TiO2 were obtained by UV-Vis spectroscopy. The conductivity of the dye, dye titanium dioxide, and TiO2 was measured by two point probe El-Kahfi 100. The DSSC based on dye titanium dioxide that stirring for 5 hours the highest efficiency of 0,0520 % whereas those based on TiO2 immersed for 36 hours showed achieved 0,0501 % obtained from I-V characterization.

Characteristics of dye Rhoeo spathacea in dye sensitizer solar cell (DSSC)

International Nuclear Information System (INIS)

Sumardiasih, Sri; Obina, Wilfrida M.; Cari; Supriyanto, Agus; Septiawan, Trio Y.; Khairuddin

2017-01-01

Dye-sensitized solar cell (DSSC) is a device that converts solar energy into electrical energy. The magnitude of the efficiency of DSSC is mainly based on the amount of dye absorbed by the surface of TiO 2 . In this work, used natural dye extracted from leaves Rhoeo spathacea. The dye partially used to immerse of TiO 2 as working electrodes, and the rest are directly mixed TiO 2 paste to obtain dye titanium dioxide.The paste TiO 2 and dye titanium dioxide coated onto the fluorine-doped tin oxide (FTO) glass plate by spin coating method. The absorbance spectra of the dye, dye titanium dioxide and TiO 2 were obtained by UV-Vis spectroscopy. The conductivity of the dye, dye titanium dioxide, and TiO 2 was measured by two point probe El-Kahfi 100. The DSSC based on dye titanium dioxide that stirring for 5 hours the highest efficiency of 0,0520 % whereas those based on TiO 2 immersed for 36 hours showed achieved 0,0501 % obtained from I-V characterization. (paper)

Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

International Nuclear Information System (INIS)

Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

2012-01-01

Highlights: ► A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. ► Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). ► PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. ► The mechanism of UBER for azo dye removal was discussed. - Abstract: Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8 ± 1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 g m −3 d −1 ) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 g m −3 d −1 (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.

Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

Energy Technology Data Exchange (ETDEWEB)

Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China); Lee, Hyung-Sool [Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West Waterloo, Ontario, Canada N2L 3G1 (Canada); Wang, Ai-Jie, E-mail: waj0578@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China)

2012-11-15

Highlights: Black-Right-Pointing-Pointer A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. Black-Right-Pointing-Pointer Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). Black-Right-Pointing-Pointer PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. Black-Right-Pointing-Pointer The mechanism of UBER for azo dye removal was discussed. - Abstract: Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8 {+-} 1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 g m{sup -3} d{sup -1}) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 g m{sup -3} d{sup -1} (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.

Destination of organic pollutants during electrochemical oxidation of biologically-pretreated dye wastewater using boron-doped diamond anode

Energy Technology Data Exchange (ETDEWEB)

Zhu, Xiuping [Department of Environmental Engineering, Peking University, the Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing100871 (China); Ni, Jinren, E-mail: nijinren@iee.pku.edu.cn [Department of Environmental Engineering, Peking University, the Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing100871 (China); Wei, Junjun; Xing, Xuan; Li, Hongna [Department of Environmental Engineering, Peking University, the Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing100871 (China)

2011-05-15

Electrochemical oxidation of biologically-pretreated dye wastewater was performed in a boron-doped diamond (BDD) anode system. After electrolysis of 12 h, the COD was decreased from 532 to 99 mg L{sup -1} (<100 mg L{sup -1}, the National Discharge Standard of China). More importantly, the destination of organic pollutants during electrochemical oxidation process was carefully investigated by molecular weight distribution measurement, resin fractionation, ultraviolet-visible spectroscopy, HPLC and GC-MS analysis, and toxicity test. As results, most organic pollutants were completely removed by electrochemical oxidation and the rest was primarily degraded to simpler compounds (e.g., carboxylic acids and short-chain alkanes) with less toxicity, which demonstrated that electrochemical oxidation of biologically-pretreated dye wastewater with BDD anode was very effective and safe. Especially, the performance of BDD anode system in degradation of large molecular organics such as humic substances makes it very promising in practical applications as an advanced treatment of biologically-pretreated wastewaters.

Destination of organic pollutants during electrochemical oxidation of biologically-pretreated dye wastewater using boron-doped diamond anode.

Science.gov (United States)

Zhu, Xiuping; Ni, Jinren; Wei, Junjun; Xing, Xuan; Li, Hongna

2011-05-15

Electrochemical oxidation of biologically-pretreated dye wastewater was performed in a boron-doped diamond (BDD) anode system. After electrolysis of 12h, the COD was decreased from 532 to 99 mg L(-1) (destination of organic pollutants during electrochemical oxidation process was carefully investigated by molecular weight distribution measurement, resin fractionation, ultraviolet-visible spectroscopy, HPLC and GC-MS analysis, and toxicity test. As results, most organic pollutants were completely removed by electrochemical oxidation and the rest was primarily degraded to simpler compounds (e.g., carboxylic acids and short-chain alkanes) with less toxicity, which demonstrated that electrochemical oxidation of biologically-pretreated dye wastewater with BDD anode was very effective and safe. Especially, the performance of BDD anode system in degradation of large molecular organics such as humic substances makes it very promising in practical applications as an advanced treatment of biologically-pretreated wastewaters. Copyright © 2011 Elsevier B.V. All rights reserved.

Destination of organic pollutants during electrochemical oxidation of biologically-pretreated dye wastewater using boron-doped diamond anode

International Nuclear Information System (INIS)

Zhu, Xiuping; Ni, Jinren; Wei, Junjun; Xing, Xuan; Li, Hongna

2011-01-01

Electrochemical oxidation of biologically-pretreated dye wastewater was performed in a boron-doped diamond (BDD) anode system. After electrolysis of 12 h, the COD was decreased from 532 to 99 mg L -1 ( -1 , the National Discharge Standard of China). More importantly, the destination of organic pollutants during electrochemical oxidation process was carefully investigated by molecular weight distribution measurement, resin fractionation, ultraviolet-visible spectroscopy, HPLC and GC-MS analysis, and toxicity test. As results, most organic pollutants were completely removed by electrochemical oxidation and the rest was primarily degraded to simpler compounds (e.g., carboxylic acids and short-chain alkanes) with less toxicity, which demonstrated that electrochemical oxidation of biologically-pretreated dye wastewater with BDD anode was very effective and safe. Especially, the performance of BDD anode system in degradation of large molecular organics such as humic substances makes it very promising in practical applications as an advanced treatment of biologically-pretreated wastewaters.

Performance Assessment of Chemical Coagulation Together with Advanced Oxidation Peroxone Regarding Dye Wastewater Treatment of Appliance Factories

Directory of Open Access Journals (Sweden)

A R Shahriyari Farfani

2016-01-01

Full Text Available Abstract Introduction: Considering the important role of industry in polluting the environment, the present study aimed to evaluate the performance of chemical coagulation together with advanced oxidation (peroxone regarding dye wastewater treatment of appliance factories. Methods: This study was experimental, which it’s pilot-scale was conducted on the wastewater of the painting appliance Factory. The sample was selected via the combined sampling procedure. The processes used in the present study consisted of chemical coagulation and advanced oxidation (peroxone processes and 250 samples were analyzed. MgCl2, PAC and FeCl3, Bentonite, Cationic Polymer were used for chemical coagulation. The used equipments consisted of Spectrophotometer DR 2000, Jar taste and a ozonation reactor. COD and dye of samples were measured according to standard method. Results: The results revealed that each of the coagulants in its optimal pH were able to arrange the magnesium chloride 86.85%, poly aluminum chloride 88.47% and ferric chloride 85.41% in removal of COD. Poly aluminum chloride achieved the highest dye removal 90.92%. Furthermore, the highest COD removal efficiency was related to the combination of magnesium chloride (1.4 mg/l, poly aluminum chloride (0.6 mg/l and cationic polymers (0.4 mg/l with an efficiency of 89.11%, which managed to remove the dye up to 93.38%. COD removal efficiency reached to 99.67% using advanced oxidation process by peroxone method on pretreated wastewater (with chemical coagulation. Conclusions: For better performance of peroxone treatment, the wastewater should be pretreated for removal of dissolved solids. As a result, due to its suspension status of using peroxone method together chemical coagulation has a high capability to remove COD and dye from appliance Factore ,s wastewater.

Characteristics of dye-sensitized solar cells using natural dye

Energy Technology Data Exchange (ETDEWEB)

Furukawa, Shoji, E-mail: furukawa@cse.kyutech.ac.j [Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka-ken 820-8502 (Japan); Iino, Hiroshi; Iwamoto, Tomohisa; Kukita, Koudai; Yamauchi, Shoji [Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka-ken 820-8502 (Japan)

2009-11-30

Dye-sensitized solar cells are expected to be used for future clean energy. Recently, most of the researchers in this field use Ruthenium complex as dye in the dye-sensitized solar cells. However, Ruthenium is a rare metal, so the cost of the Ruthenium complex is very high. In this paper, various dye-sensitized solar cells have been fabricated using natural dye, such as the dye of red-cabbage, curcumin, and red-perilla. As a result, it was found that the conversion efficiency of the solar cell fabricated using the mixture of red-cabbage and curcumin was about 0.6% (light source: halogen lamp), which was larger than that of the solar cells using one kind of dye. It was also found that the conversion efficiency was about 1.0% for the solar cell with the oxide semiconductor film fabricated using polyethylene glycol (PEG) whose molecular weight was 2,000,000 and red-cabbage dye. This indicates that the cost performance (defined by [conversion efficiency]/[cost of dye]) of the latter solar cell (dye: red-cabbage) is larger by more than 50 times than that of the solar cell using Ruthenium complex, even if the effect of the difference between the halogen lamp and the standard light source is taken into account.

Theoretical study of indoline dyes for dye-sensitized solar cells

International Nuclear Information System (INIS)

Ham, Ho Wan; Kim, Young Sik

2010-01-01

Indoline dye sensitizers were designed and studied theoretically to increase molar extinction coefficients in the visible to near infrared region for solar-cell devices. To gain insight into dye sensitizers' structural, electronic, and optical properties, DFT/TDDFT calculations were performed on a series of dye sensitizers derived from the D149. The good agreement between the experimental and TDDFT calculated absorption spectra of the D149 sensitizer allowed us to provide a detailed assessment of the main spectral features of a series of dye sensitizers. Increase in the conjugation length resulted in a more red-shifted spectral response and less positive oxidation potential than that of the D149. The dye with the dimethylfluorene group showed stronger absorption bands due to a large dipole moment. The calculated dipoles for the dye series correlate well with the observed strong absorption bands of the electronic spectra. These results provided useful clues for the molecular engineering of efficient organic dye sensitizers.

Application of Ni-Oxide@TiO2 Core-Shell Structures to Photocatalytic Mixed Dye Degradation, CO Oxidation, and Supercapacitors

Directory of Open Access Journals (Sweden)

Seungwon Lee

2016-12-01

Full Text Available Performing diverse application tests on synthesized metal oxides is critical for identifying suitable application areas based on the material performances. In the present study, Ni-oxide@TiO2 core-shell materials were synthesized and applied to photocatalytic mixed dye (methyl orange + rhodamine + methylene blue degradation under ultraviolet (UV and visible lights, CO oxidation, and supercapacitors. Their physicochemical properties were examined by field-emission scanning electron microscopy, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, and UV-visible absorption spectroscopy. It was shown that their performances were highly dependent on the morphology, thermal treatment procedure, and TiO2 overlayer coating.

UV-visible spectroscopic estimation of photodegradation of rhodamine-B dye using tin(IV) oxide nanoparticles.

Science.gov (United States)

Sangami, G; Dharmaraj, N

2012-11-01

Nanocrystalline, tin(IV) oxide (SnO(2)) particles has been prepared by thermal decomposition of tin oxalate precursor obtained from the reactions of tin(IV) chloride and sodium oxalate using eggshell membrane (ESM). The as-prepared SnO(2) nanoparticles were characterized by thermal studies, transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman, FT-IR and UV-visible studies and used as a photocatalyst for the degradation of rhodamine-B (Rh-B) dye. The size of the prepared nanoparticles was in the range of 5-12nm as identified from the TEM images. Powder XRD data revealed the presence of a tetragonal, rutile crystalline phase of the tin(IV) oxide nanoparticles. Thermal analysis showed that the decomposition of tin oxalate precursor to yield the titled tin(IV) oxide nanoparticles was completed below 500°C. The extent of degradation of Rh-B in the presence of SnO(2) monitored by absorption spectral measurements demonstrated that 94.48% of the selected dye was degraded upon irradiation with UV light for 60 min. Copyright © 2012 Elsevier B.V. All rights reserved.

Is TrichoScan a new diagnostic method for diffuse hair loss?

Science.gov (United States)

Uce Özkol, Hatice; Çalka, Ömer; Akdeniz, Necmettin

2014-01-01

In this study, we investigated the sensitivity of TrichoScan, a computer-based phototrichogram, in the evaluation of diffuse hair loss in women and the relationship between iron deficiency anemia and hair loss. We recruited 100 female patients with diffuse hair loss. In all of the patients, a 1-cm2 area of hair located in a temporoparietal region was shortened to 0.5 mm. The shaved scalp regions were stained with black dye. The subject then waited for 12 min. Subsequently, pictures of these regions were taken with a videodermoscope and analyzed with the TrichoScan software program. The ferritin levels were markedly low in these groups. The ratio of anagen was highest in the telogen effluvium (TE) mild group, followed by the TE severe group, and was lowest in the androgenetic alopecia (AGA) group (P hair analysis results with the TrichoScan software were satisfactory and the results were consistent with the clinical diagnosis. In particular, the use of TrichoScan was very successful in the differentiation between AGA and TE.

Nitrogen doped nanocrystalline semiconductor metal oxide: An efficient UV active photocatalyst for the oxidation of an organic dye using slurry Photoreactor.

Science.gov (United States)

Ramachandran, Saranya; Sivasamy, A; Kumar, B Dinesh

2016-12-01

Water pollution is a cause for serious concern in today's world. A major contributor to water pollution is industrial effluents containing dyes and other organic molecules. Waste water treatment has become a priority area in today's applied scientific research as it seeks to minimize the toxicity of the effluents being discharged and increase the possibility of water recycling. An efficient and eco-friendly way of degrading toxic molecules is to use nano metal-oxide photocatalysts. The present study aims at enhancing the photocatalytic activity of a semiconductor metal oxide by doping it with nitrogen. A sol-gel cum combustion method was employed to synthesize the catalyst. The prepared catalyst was characterized by FT-IR, XRD, UV-DRS, FESEM and AFM techniques. UV-DRS result showed the catalyst to possess band gap energy of 2.97eV, thus making it active in the UV region of the spectrum. Its photocatalytic activity was evaluated by the degradation of a model pollutant-Orange G dye, under UV light irradiation. Preliminary experiments were carried out to study the effects of pH, catalyst dosage and initial dye concentration on the extent of dye degradation. Kinetic studies revealed that the reaction followed pseudo first order kinetics. The effect of electrolytes on catalyst efficiency was also studied. The progress of the reaction was monitored by absorption studies and measuring the reduction in COD. The catalyst thus prepared was seen to have a high photocatalytic efficiency. The use of this catalyst is a promising means of waste water treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

Decolorization and removal of cod and bodfrom raw and biotreated textile dye bath effluent through advanced oxidation processes (AOPS

Directory of Open Access Journals (Sweden)

A. Muhammad

2008-09-01

Full Text Available In this paper, a comparative study of the treatment of raw and biotreated (upflow anaerobic sludge blanket, UASB textile dye bath effluent using advanced oxidation processes (AOPs is presented. The AOPs applied on raw and biotreated textile dye bath effluent, after characterization in terms of COD, colour, BOD and pH, were ozone, UV, UV/H2O2 and photo-Fenton. The decolorization of raw dye bath effluent was 58% in the case of ozonation. However it was 98% in the case of biotreated dye bath effluent when exposed to UV/H2O2. It is, therefore, suggested that a combination of biotreatment and AOPs be adopted to decolorize dye bath effluent in order to make the process more viable and effective. Biodegradability was also improved by applying AOPs after biotreatment of dye bath effluent.

Synthesis of Polyaniline-Coated Graphene Oxide@SrTiO3 Nanocube Nanocomposites for Enhanced Removal of Carcinogenic Dyes from Aqueous Solution

Directory of Open Access Journals (Sweden)

Syed Shahabuddin

2016-09-01

Full Text Available The present investigation highlights the synthesis of polyaniline (PANI-coated graphene oxide doped with SrTiO3 nanocube nanocomposites through facile in situ oxidative polymerization method for the efficient removal of carcinogenic dyes, namely, the cationic dye methylene blue (MB and the anionic dye methyl orange (MO. The presence of oxygenated functional groups comprised of hydroxyl and epoxy groups in graphene oxide (GO and nitrogen-containing functionalities such as imine groups and amine groups in polyaniline work synergistically to impart cationic and anionic nature to the synthesised nanocomposite, whereas SrTiO3 nanocubes act as spacers aiding in segregation of GO sheets, thereby increasing the effective surface area of nanocomposite. The synthesised nanocomposites were characterised by field emission scanning electron microscopy (FESEM, transmission electron microscopy (TEM, thermogravimetric analysis (TGA, X-ray diffraction (XRD, and Fourier transform infrared spectroscopy (FTIR. The adsorption efficiencies of graphene oxide (GO, PANI homopolymer, and SrTiO3 nanocubes-doped nanocomposites were assessed by monitoring the adsorption of methylene blue and methyl orange dyes from aqueous solution. The adsorption efficiency of nanocomposites doped with SrTiO3 nanocubes were found to be of higher magnitude as compared with undoped nanocomposite. Moreover, the nanocomposite with 2 wt % SrTiO3 with respect to graphene oxide demonstrated excellent adsorption behaviour with 99% and 91% removal of MB and MO, respectively, in a very short duration of time.

Optimization of the C11-BODIPY(581/591) dye for the determination of lipid oxidation in Chlamydomonas reinhardtii by flow cytometry.

Science.gov (United States)

Cheloni, Giulia; Slaveykova, Vera I

2013-10-01

Lipid oxidation is a recognized end point for the study of oxidative stress and is an important parameter to describe the mode of micropollutant action on aquatic microorganisms. Therefore, the development of quick and reliable methodologies probing the oxidative stress and damage in living cells is highly sought. In the present proof-of-concept work, we examined the potential of the fluorescent dye C11-BODIPY(591/581) to probe lipid oxidation in the green microalga Chlamydomonas reinhardtii. C11-BODIPY(591/581) staining was combined with flow cytometry measurements to obtain multiparameter information on cellular features and oxidative stress damage within single cells. First, staining conditions were optimized by exploring the capability of the dye to stain algal cells under increasing cell and dye concentrations and different staining procedures. Then lipid oxidation in algae induced by short- and long-term exposures to the three metallic micropollutants, copper, mercury, and nanoparticulate copper oxide, and the two organic contaminants, diethyldithiocarbamate (DDC) and diuron was determined. In this work we pointed out C11-BODIPY(591/581) applicability in a wide range of exposure conditions, including studies of oxidation as a function of time and that it is suitable for in vivo measurements of lipid oxidation due to its high permeation and stability in cells and its low interference with algal autofluorescence. © 2013 International Society for Advancement of Cytometry. Copyright © 2013 International Society for Advancement of Cytometry.

Gold Decorated Graphene for Rapid Dye Reduction and Efficient Electro Catalytic Oxidation of Ethanol

Science.gov (United States)

Siddhardha, R. S.; Kumar v, Lakshman; Kaniyoor, A.; Podila, R.; Kumar, V. S.; Venkataramaniah, K.; Ramaprabhu, S.; Rao, A.; Ramamurthy, S. S.; Clemson University Team; Sri Sathya Sai Institute of Higher Learning Team; IITMadras Team

2013-03-01

A well known disadvantage in fabrication of metal-graphene composite is the use of surfactants that strongly adsorb on the surface and reduce the performance of the catalyst. Here, we demonstrate a novel one pot synthesis of gold nanoparticles (AuNPs) by laser ablation of gold strip and simultaneous decoration of these on functionalized graphene derivatives. Not only the impregnation of AuNPs was linker free, but also the synthesis by itself was surfactant free. This resulted in in-situ decoration of pristine AuNPs on functionalized graphene derivatives. These materials were well characterized and tested for catalytic applications pertaining to dye reduction and electrooxidation. The catalytic reduction rates are 1.4 x 102 and 9.4x102 times faster for Rhodamine B and Methylene Blue dyes respectively, compared to earlier reports. The enhanced rate involves synergistic interplay of electronic relay between AuNPs and the dye, also charge transfer between the graphene system and dye. In addition, the onset potential for ethanol oxidation was found to be more negative ~ 100 mV, an indication of its promising application in direct ethanol fuel cells.

One-Pot Facile Methodology to Synthesize Chitosan-ZnO-Graphene Oxide Hybrid Composites for Better Dye Adsorption and Antibacterial Activity

Directory of Open Access Journals (Sweden)

Anandhavelu Sanmugam

2017-11-01

Full Text Available Novel chitosan–ZnO–graphene oxide hybrid composites were prepared using a one-pot chemical strategy, and their dye adsorption characteristics and antibacterial activity were demonstrated. The prepared chitosan and the hybrids such as chitosan–ZnO and chitosan–ZnO–graphene oxide were characterized by UV-Vis absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The thermal and mechanical properties indicate a significant improvement over chitosan in the hybrid composites. Dye adsorption experiments were carried out using methylene blue and chromium complex as model pollutants with the function of dye concentration. The antibacterial properties of chitosan and the hybrids were tested against Gram-positive and Gram-negative bacterial species, which revealed minimum inhibitory concentrations (MICs of 0.1 µg/mL.

Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction

International Nuclear Information System (INIS)

Vallet, Ana; Ovejero, Gabriel; Rodríguez, Araceli; Peres, José A.; García, Juan

2013-01-01

Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Chromotrope 2R removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to bare-usable after in situ regeneration. -- Abstract: Active nickel catalysts (7 wt%) supported over Mg–Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min −1 and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min −1 , respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T r = 0.098 g Ni min mL −1 . After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T r = 0.098 g Ni min mL −1 , attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity

Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction

Energy Technology Data Exchange (ETDEWEB)

Vallet, Ana [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Ovejero, Gabriel, E-mail: govejero@quim.ucm.es [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Rodríguez, Araceli [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Peres, José A. [Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal); García, Juan, E-mail: juangcia@quim.ucm.es [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

2013-01-15

Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Chromotrope 2R removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to bare-usable after in situ regeneration. -- Abstract: Active nickel catalysts (7 wt%) supported over Mg–Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min{sup −1} and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min{sup −1}, respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T{sub r} = 0.098 g{sub Ni} min mL{sup −1}. After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T{sub r} = 0.098 g{sub Ni} min mL{sup −1}, attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity.

Enhancing the electrochemical oxidation of acid-yellow 36 azo dye using boron-doped diamond electrodes by addition of ferrous ion

International Nuclear Information System (INIS)

Villanueva-Rodriguez, M.; Hernandez-Ramirez, A.; Peralta-Hernandez, J.M.; Bandala, Erick R.; Quiroz-Alfaro, Marco A.

2009-01-01

This work shows preliminary results on the electrochemical oxidation process (EOP) using boron-doped diamond (BDD) electrode for acidic yellow 36 oxidation, a common azo dye used in textile industry. The study is centred in the synergetic effect of ferrous ions and hydroxyl free radicals for improving discoloration of azo dye. The assays were carried out in a typical glass cell under potentiostatic conditions. On experimental conditions, the EOP was able to partially remove the dye from the reaction mixture. The reaction rate increased significantly by addition of Fe 2+ (1 mM as ferrous sulphate) to the system and by (assumed) generation of ferrate ion [Fe(VI)] over BDD electrode. Ferrate is considered as a highly oxidizing reagent capable of removing the colorant from the reaction mixture, in synergistic action with the hydroxyl radicals produced on the BDD surface. Further increases in the Fe 2+ concentration lead to depletion of the reaction rate probably due to the hydroxyl radical scavenging effect of Fe 2+ excess in the system.

Gold nanoworms immobilized graphene oxide polymer brush nanohybrid for catalytic degradation studies of organic dyes

International Nuclear Information System (INIS)

Mogha, Navin Kumar; Gosain, Saransh; Masram, Dhanraj T.

2017-01-01

Highlights: • AuNPs on PDMAEMA brushes immobilized reduced graphene oxide was used as catalyst. • A novel highly efficient, reusable heterogeneous catalyst for dyes degradation. • Rhodamine B, Methyl Orange and Eosin Y was used for study. • Apparent rate constant observed was 21.8, 26.2, and 8.7 (×10 −3 s −1 ) respectively. - Abstract: In the present work, we report gold nanoparticles (AuNPs) on poly (dimethylaminoethyl methacrylate) (PDMAEMA) brushes immobilized reduced graphene oxide (Au/PDMAEMA/RGO) as catalyst for degradation kinetic studies of Rhodamine B (RB), Methyl Orange (MO) and Eosine Y (EY) dyes, having an excellent catalytic activity, as evident by the apparent rate constant (k app ), which is found to be 21.8, 26.2, and 8.7 (×10 −3 s −1 ), for RB, MO and EY respectively. Au/PDMAEMA/RGO catalyst is easy to use, highly efficient, recyclable, which make it suitable for applications in waste water management. Foremost, synthesis of PDMAEMA brushes on graphene oxide is accomplished by Atom transfer radical polymerization method (ATRP), whereas AuNPs are synthesized by simple chemical reduction method.

Gold nanoworms immobilized graphene oxide polymer brush nanohybrid for catalytic degradation studies of organic dyes

Energy Technology Data Exchange (ETDEWEB)

Mogha, Navin Kumar; Gosain, Saransh; Masram, Dhanraj T., E-mail: dhnaraj_masram27@rediffmail.com

2017-02-28

Highlights: • AuNPs on PDMAEMA brushes immobilized reduced graphene oxide was used as catalyst. • A novel highly efficient, reusable heterogeneous catalyst for dyes degradation. • Rhodamine B, Methyl Orange and Eosin Y was used for study. • Apparent rate constant observed was 21.8, 26.2, and 8.7 (×10{sup −3} s{sup −1}) respectively. - Abstract: In the present work, we report gold nanoparticles (AuNPs) on poly (dimethylaminoethyl methacrylate) (PDMAEMA) brushes immobilized reduced graphene oxide (Au/PDMAEMA/RGO) as catalyst for degradation kinetic studies of Rhodamine B (RB), Methyl Orange (MO) and Eosine Y (EY) dyes, having an excellent catalytic activity, as evident by the apparent rate constant (k{sub app}), which is found to be 21.8, 26.2, and 8.7 (×10{sup −3} s{sup −1}), for RB, MO and EY respectively. Au/PDMAEMA/RGO catalyst is easy to use, highly efficient, recyclable, which make it suitable for applications in waste water management. Foremost, synthesis of PDMAEMA brushes on graphene oxide is accomplished by Atom transfer radical polymerization method (ATRP), whereas AuNPs are synthesized by simple chemical reduction method.

HCN channels are not required for mechanotransduction in sensory hair cells of the mouse inner ear.

Directory of Open Access Journals (Sweden)

Geoffrey C Horwitz

Full Text Available The molecular composition of the hair cell transduction channel has not been identified. Here we explore the novel hypothesis that hair cell transduction channels include HCN subunits. The HCN family of ion channels includes four members, HCN1-4. They were originally identified as the molecular correlates of the hyperpolarization-activated, cyclic nucleotide gated ion channels that carry currents known as If, IQ or Ih. However, based on recent evidence it has been suggested that HCN subunits may also be components of the elusive hair cell transduction channel. To investigate this hypothesis we examined expression of mRNA that encodes HCN1-4 in sensory epithelia of the mouse inner ear, immunolocalization of HCN subunits 1, 2 and 4, uptake of the transduction channel permeable dye, FM1-43 and electrophysiological measurement of mechanotransduction current. Dye uptake and transduction current were assayed in cochlear and vestibular hair cells of wildtype mice exposed to HCN channel blockers or a dominant-negative form of HCN2 that contained a pore mutation and in mutant mice that lacked HCN1, HCN2 or both. We found robust expression of HCNs 1, 2 and 4 but little evidence that localized HCN subunits in hair bundles, the site of mechanotransduction. Although high concentrations of the HCN antagonist, ZD7288, blocked 50-70% of the transduction current, we found no reduction of transduction current in either cochlear or vestibular hair cells of HCN1- or HCN2- deficient mice relative to wild-type mice. Furthermore, mice that lacked both HCN1 and HCN2 also had normal transduction currents. Lastly, we found that mice exposed to the dominant-negative mutant form of HCN2 had normal transduction currents as well. Taken together, the evidence suggests that HCN subunits are not required for mechanotransduction in hair cells of the mouse inner ear.

New porous titanium–niobium oxide for photocatalytic degradation of bromocresol green dye in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Chaleshtori, Maryam Zarei, E-mail: mzarei@utep.edu [Materials Research and Technology Institute (MRTI), University of Texas at El Paso, 500W. University Ave., El Paso, TX 79968 (United States); Hosseini, Mahsa; Edalatpour, Roya [Materials Research and Technology Institute (MRTI), University of Texas at El Paso, 500W. University Ave., El Paso, TX 79968 (United States); Masud, S.M. Sarif [Department of Chemistry, University of Texas at El Paso, 500W. University Ave., El Paso, TX 79968 (United States); Chianelli, Russell R., E-mail: chianell@utep.edu [Materials Research and Technology Institute (MRTI), University of Texas at El Paso, 500W. University Ave., El Paso, TX 79968 (United States)

2013-10-15

Graphical abstract: The photocatalytic activity of different porous titanium–niobium oxides was evaluated toward degradation of bromocresol green (BG) under UV light. A better catalytic activity was observed for all samples at lower pH. Catalysts have a stronger ability for degradation of BG in acid media than in alkaline media. - Highlights: • Different highly structured titanium–niobium oxides have been prepared using improved methods of synthesis. • Photo-degradation of bromocresol green dye (BG) with nanostructure titanium–niobium oxide catalysts was carried out under UV light. • The photo-catalytic activity of all catalysts was higher in lower pH. • Titanium–niobium oxide catalysts are considerably stable and reusable. - Abstract: In this study, high surface area semiconductors, non porous and porous titanium–niobium oxides derived from KTiNbO{sub 5} were synthesized, characterized and developed for their utility as photocatalysts for decontamination with sunlight. These materials were then used in the photocatalytic degradation of bromocresol green dye (BG) in aqueous solution using UV light and their catalytic activities were evaluated at various pHs. For all catalysts, the photocatalytic degradation of BG was most efficient in acidic solutions. Results show that the new porous oxides have large porous and high surface areas and high catalytic activity. A topotactic dehydration treatment greatly improves catalyst performance at various pHs. Stability and long term activity of porous materials (topo and non-topo) in photocatalysis reactions was also tested. These results suggest that the new materials can be used to efficiently purify contaminated water.

Mesoporous cerium oxide nanospheres for the visible-light driven photocatalytic degradation of dyes

Directory of Open Access Journals (Sweden)

Subas K. Muduli

2014-04-01

Full Text Available A facile, solvothermal synthesis of mesoporous cerium oxide nanospheres is reported for the purpose of the photocatalytic degradation of organic dyes and future applications in sustainable energy research. The earth-abundant, relatively affordable, mixed valence cerium oxide sample, which consists of predominantly Ce7O12, has been characterized by powder X-ray diffraction, X-ray photoelectron and UV–vis spectroscopy, and transmission electron microscopy. Together with N2 sorption experiments, the data confirms that the new cerium oxide material is mesoporous and absorbs visible light. The photocatalytic degradation of rhodamin B is investigated with a series of radical scavengers, suggesting that the mechanism of photocatalytic activity under visible-light irradiation involves predominantly hydroxyl radicals as the active species.

Age-related hair pigment loss.

Science.gov (United States)

Tobin, Desmond J

2015-01-01

Humans are social animals that communicate disproportionately via potent genetic signals imbued in the skin and hair, including racial, ethnic, health, gender, and age status. For the vast majority of us, age-related hair pigment loss becomes the inescapable signal of our disappearing youth. The hair follicle (HF) pigmentary unit is a wonderful tissue for studying mechanisms generally regulating aging, often before this becomes evident elsewhere in the body. Given that follicular melanocytes (unlike those in the epidermis) are regulated by the hair growth cycle, this cycle is likely to impact the process of aging in the HF pigmentary unit. The formal identification of melanocyte stem cells in the mouse skin has spurred a flurry of reports on the potential involvement of melanocyte stem cell depletion in hair graying (i.e., canities). Caution is recommended, however, against simple extrapolation of murine data to humans. Regardless, hair graying in both species is likely to involve an age-related imbalance in the tissue's oxidative stress handling that will impact not only melanogenesis but also melanocyte stem cell and melanocyte homeostasis and survival. There is some emerging evidence that the HF pigmentary unit may have regenerative potential, even after it has begun to produce white hair fibers. It may therefore be feasible to develop strategies to modulate some aging-associated changes to maintain melanin production for longer. © 2015 S. Karger AG, Basel.

An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment

International Nuclear Information System (INIS)

Aravind, Priyadharshini; Selvaraj, Hosimin; Ferro, Sergio; Sundaram, Maruthamuthu

2016-01-01

Highlights: • Firstly, the mediated electro-oxidation allows rapid discoloration of the effluent. • Cost effective sunlight-mediated removal of bio-toxic active chlorine species. • Electrochemical pretreatment enhances the biodegradability of textile wastewater. • About 90% COD removal was achieved by a subsequent biodegradation. • By-products from degradation of dyes have shown to be ecofriendly and non-toxic. - Abstract: A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO_2-RuO_2-TiO_2 anodes), lead to discoloration by 92% and 89%, respectively, in 100 min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition. Results show that the electrochemical discoloration enhances the effluent biodegradability with about 90% COD removal employing acclimatized naphthalene-degrading bacterial consortia, within 144 h. Based on results obtained through FT-IR and GC–MS, it is likely that azo group stripping and oxidative cleavage of dyes occur due to the nucleophilic attack of active chlorine species during electro-oxidation. This leads to generation of aromatic intermediates which are further desulfonated, deaminated or oxidized only at their functional groups. These aromatic intermediates were mineralized into simpler organic acids and aldehydes by bacterial consortia. Phyto-toxicity trials on Vigna radiata confirmed the toxic nature of the untreated dye solutions. An increase in root and shoot development was observed with the electrochemically treated solutions, the same was higher in case of bio-treated solutions. Overall, obtained results confirm the capability of the proposed hybrid oxidation scheme for the remediation of textile wastewater.

THE DIMINISHING OF THE CONTENT OF TEXTILE DIRECT DYES AND AUXILIARY COMPOUNDS DURING THEIR CATALYTIC OXIDATION

Directory of Open Access Journals (Sweden)

Maria Gonta

2014-06-01

Full Text Available Advanced oxidation methods of organic compounds lead to their partial mineralization and increase of the adsorption process efficiency on the surface of oxidized activated carbon. We have studied the oxidation process using model solutions containing mixture of dye direct brown (DB, ethylene glycol (EGL and sodium lauryl sulfate (SLS under the action of Fenton reagent, in the presence and absence of UV irradiation or under the action of electric current (in the electrochemical cell. The same studies were performed by replacing the iron (II ion with titanium dioxide.

Fast degradation of dyes in water using manganese-oxide-coated diatomite for environmental remediation

Science.gov (United States)

Dang, Trung-Dung; Banerjee, Arghya Narayan; Tran, Quang-Tung; Roy, Sudipta

2016-11-01

By a simple wet-chemical procedure using a permanganate in the acidic medium, diatomite coated with amorphous manganese oxide nanoparticles was synthesized. The structural, microstructural and morphological characterizations of the as-synthesized catalysts confirmed the nanostructure of MnO2 and its stabilization on the support - diatomite. The highly efficient and rapid degradation of methylene blue and methyl orange over synthesized MnO2 coated Diatomite has been carried out. The results revealed considerably faster degradation of the dyes against the previously reported data. The proposed mechanism of the dye-degradation is considered to be a combinatorial effect of chemical, physicochemical and physical processes. Therefore, the fabricated catalysts have potential application in waste water treatment, and pollution degradation for environmental remediation.

Application of natural dyes in textile industry and the treatment of dye solutions using electrolytic techniques

OpenAIRE

Abouamer, Karima Massaud

2008-01-01

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 25/02/2008. Anodic oxidation of a commercial dye, methylene blue (MB), from aqueous solutions using an electrochemical cell is reported. Data are provided on the effects of eight different types of supporting electrolytes, concentration of electrolytes, initial dye concentration, current and electrolytic time on the percentage removal of methylene blue. Anodic oxidation was found to be effect...

Fluorine-induced apoptosis and lipid peroxidation in human hair follicles in vitro.

Science.gov (United States)

Wang, Zheng-hui; Li, Xiao-li; Yang, Zhuang-qun; Xu, Min

2010-12-01

Fluoride is an essential trace element for human body; however, exposure to high amounts of fluoride has been documented to be correlated with an increasing risk of hair loss. To date, little is known about the mechanism(s) of how fluoride affects hair follicles. Here, we demonstrated that middle (1.0 mmol/L) and high (10.0 mmol/L) concentrations of sodium fluoride (NaF) significantly inhibited hair follicle elongation in vitro, but low NaF (0.1 mmol/L) showed little influence. Moreover, treatment with high levels of NaF resulted in a marked increase in terminal dUTP nick end labeling-positive cells in the outer layer of the outer root sheath, the dermal sheath, and the lower bulb matrix surrounding dermal papilla. Furthermore, the enhanced apoptosis was coupled with an increased oxidative stress manifested as higher malondialdehyde content. Additionally, the presence of selenium considerably antagonized the effects of middle NaF on hair follicles, with regard to either the suppression of hair growth or the induction of oxidative stress and apoptosis. In conclusion, exposure to high levels of fluoride compromises hair follicle growth and accelerate cell apoptosis in vitro. The toxicity of fluoride can be reduced by selenium, at least partially via the suppression of intracellular oxidative stress.

Photocatalytic Oxidation of Azo Dyes and Oxalic Acid in Batch Reactors and CSTR: Introduction of Photon Absorption by Dyes to Kinetic Models

Directory of Open Access Journals (Sweden)

I. Grčić

2018-04-01

Full Text Available The possibilities of treating industrial effluents and water purification by advanced oxidation processes have been extensively studied; photocatalysis has emerged as a feasible alternative solution. In order to apply the photocatalytic treatment on a larger scale, relevant modeling approaches are necessary. The scope of this work was to investigate the applicability of recently published kinetic models in different reactor systems (batch and CSTR under UVA or UVC irradiation and in combination with two types of TiO2 catalyst, AEROXIDE® P25 and PC-500 for degradation of azo dyes (C.I. Reactive Violet 2, and C.I. Mordant Yellow 10, oxalic acid and their mixtures. The influences of reactor geometry and irradiation intensities on pollutant oxidation efficiency were examined. The effect of photon absorption by dyes in water matrix was thoroughly studied. Relevant kinetic models were introduced to the mass balance for particular reactor system. Resulting models were sufficient for description of pollutant degradation in batch reactors and CSTR. Experimental results showed 1.15 times higher mineralization extents achieved after 7 cycles in CSTR than in batch photoreactor of similar geometry within the equivalent time-span. The application of CSTR in-series could simplify the photocatalytic water treatment on a larger scale.

Synthesis and Application of Iron Oxide/Silica Gel Nanocomposite for Removal of Sulfur Dyes from Aqueous Solutions

Directory of Open Access Journals (Sweden)

Naser Tavassoli

2017-03-01

Full Text Available Background & Aims of the Study: water pollution by synthetic organic dyes is mainly regarded as environmental and ecological critical issues worldwide. In this research, magnetite iron oxide/silica gel nanocomposite (termed as Fe3O4/SG was synthesized chemically and then used as an effective adsorbent for removal of sulfur dyes from aqueous solution. Materials and Methods: The various parameters such as pH, sorbent dosage, initial dye concentration, contact time and dye solution temperature were investigated in a batch system. The equilibrium data were analyzed by Langmuir and Freundlich isotherm models. Results: The experimental data fit well with pseudo-second-order kinetic model (R2≥0.998 and conformed better to Langmuir isotherm model (R2≥0.997. The maximum adsorption capacity for Fe3O4/SG obtained from the Langmuir model was 11.1mg/g. Evaluation of thermodynamic parameters proved that the adsorption process was normally feasible, spontaneous and exothermic. Conclusion: It can be concluded that the Fe3O4/SG can be considered as a cost-effective and an environmental friendly adsorbent for efficient removal of sulfur dyes from aqueous solutions.

An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment

Energy Technology Data Exchange (ETDEWEB)

Aravind, Priyadharshini, E-mail: priya.bdu07@gmail.com [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India); Selvaraj, Hosimin [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India); Ferro, Sergio [Ecas4 Australia, Unit 8, 1 London Road, Mile End, South Australia 5031 (Australia); Sundaram, Maruthamuthu [Corrosion and Materials Protection Division (CMPD), CSIR—Central electrochemical research institute (CECRI), Karaikudi 630 003 (India)

2016-11-15

Highlights: • Firstly, the mediated electro-oxidation allows rapid discoloration of the effluent. • Cost effective sunlight-mediated removal of bio-toxic active chlorine species. • Electrochemical pretreatment enhances the biodegradability of textile wastewater. • About 90% COD removal was achieved by a subsequent biodegradation. • By-products from degradation of dyes have shown to be ecofriendly and non-toxic. - Abstract: A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO{sub 2}-RuO{sub 2}-TiO{sub 2} anodes), lead to discoloration by 92% and 89%, respectively, in 100 min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition. Results show that the electrochemical discoloration enhances the effluent biodegradability with about 90% COD removal employing acclimatized naphthalene-degrading bacterial consortia, within 144 h. Based on results obtained through FT-IR and GC–MS, it is likely that azo group stripping and oxidative cleavage of dyes occur due to the nucleophilic attack of active chlorine species during electro-oxidation. This leads to generation of aromatic intermediates which are further desulfonated, deaminated or oxidized only at their functional groups. These aromatic intermediates were mineralized into simpler organic acids and aldehydes by bacterial consortia. Phyto-toxicity trials on Vigna radiata confirmed the toxic nature of the untreated dye solutions. An increase in root and shoot development was observed with the electrochemically treated solutions, the same was higher in case of bio-treated solutions. Overall, obtained results confirm the capability of the proposed hybrid oxidation scheme for the remediation of textile wastewater.

Influence of mass transfer and chemical reaction on ozonation of azo dyes

Energy Technology Data Exchange (ETDEWEB)

Choi, I.S.; Wiesmann, U. [Dept. of Environmental Engineering, Technical Univ. of Berlin, Berlin (Germany)

2003-07-01

Azo dyes can be only mineralised by chemical oxidation. In this paper the oxidation of reactive black 5 (RB 5) and reactive orange 96 (RO 96) with concentrations between 35 and 5700 mgL{sup -1} (RB 5) and between 20 and 2050 mgL{sup -1} (RO 96) is investigated. A lab scale bubble column was used, which was gassed by a mixture of O{sub 2} and O{sub 3}. The oxidation rate was influenced by mass transfer for all dye concentrations used. For lower dye concentrations mass transfer alone was decisive for reaction rate showing an enhancement factor of E {approx} 1. However, in the region of higher dye concentrations, the slope of the decreasing ozone concentration inside the liquid boundary layer increases more and more with increasing dye concentration as a result of a chemical oxidation. Therefore, the enhancement factor depends on the kind and concentration of the azo dyes. For RB 5 as an diazo dye an enhancement factor of E = 9 was observed for 3800 mgL{sup -1}, RO 96 as a mono azo dye with a remarkable higher chemical oxidation rate shows an E = 17 already for 2050 mgL{sup -1}. (orig.)

Immobilized Lignin Peroxidase-Like Metalloporphyrins as Reusable Catalysts in Oxidative Bleaching of Industrial Dyes

Directory of Open Access Journals (Sweden)

Paolo Zucca

2016-07-01

Full Text Available Synthetic and bioinspired metalloporphyrins are a class of redox-active catalysts able to emulate several enzymes such as cytochromes P450, ligninolytic peroxidases, and peroxygenases. Their ability to perform oxidation and degradation of recalcitrant compounds, including aliphatic hydrocarbons, phenolic and non-phenolic aromatic compounds, sulfides, and nitroso-compounds, has been deeply investigated. Such a broad substrate specificity has suggested their use also in the bleaching of textile plant wastewaters. In fact, industrial dyes belong to very different chemical classes, being their effective and inexpensive oxidation an important challenge from both economic and environmental perspective. Accordingly, we review here the most widespread synthetic metalloporphyrins, and the most promising formulations for large-scale applications. In particular, we focus on the most convenient approaches for immobilization to conceive economical affordable processes. Then, the molecular routes of catalysis and the reported substrate specificity on the treatment of the most diffused textile dyes are encompassed, including the use of redox mediators and the comparison with the most common biological and enzymatic alternative, in order to depict an updated picture of a very promising field for large-scale applications.

Dynamical Orientation of Large Molecules on Oxide Surfaces and its Implications for Dye-Sensitized Solar Cells

KAUST Repository

Brennan, Thomas P.

2013-11-12

A dual experimental-computational approach utilizing near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and density functional theory-molecular dynamics (DFT-MD) is presented for determining the orientation of a large adsorbate on an oxide substrate. A system of interest in the field of dye-sensitized solar cells is studied: an organic cyanoacrylic acid-based donor-π-acceptor dye (WN1) bound to anatase TiO2. Assessment of nitrogen K-edge NEXAFS spectra is supported by calculations of the electronic structure that indicate energetically discrete transitions associated with the two π systems of the C-N triple bond in the cyanoacrylic acid portion of the dye. Angle-resolved NEXAFS spectra are fitted to determine the orientation of these two orbital systems, and the results indicate an upright orientation of the adsorbed dye, 63 from the TiO2 surface plane. These experimental results are then compared to computational studies of the WN1 dye on an anatase (101) TiO2 slab. The ground state structure obtained from standard DFT optimization is less upright (45 from the surface) than the NEXAFS results. However, DFT-MD simulations, which provide a more realistic depiction of the dye at room temperature, exhibit excellent agreement - within 2 on average - with the angles determined via NEXAFS, demonstrating the importance of accounting for the dynamic nature of adsorbate-substrate interactions and DFT-MD\\'s powerful predictive abilities. © 2013 American Chemical Society.

Dynamical Orientation of Large Molecules on Oxide Surfaces and its Implications for Dye-Sensitized Solar Cells

KAUST Repository

Brennan, Thomas P.; Tanskanen, Jukka T.; Bakke, Jonathan R.; Nguyen, William H.; Nordlund, Dennis; Toney, Michael F.; McGehee, Michael D.; Sellinger, Alan; Bent, Stacey F.

2013-01-01

A dual experimental-computational approach utilizing near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and density functional theory-molecular dynamics (DFT-MD) is presented for determining the orientation of a large adsorbate on an oxide substrate. A system of interest in the field of dye-sensitized solar cells is studied: an organic cyanoacrylic acid-based donor-π-acceptor dye (WN1) bound to anatase TiO2. Assessment of nitrogen K-edge NEXAFS spectra is supported by calculations of the electronic structure that indicate energetically discrete transitions associated with the two π systems of the C-N triple bond in the cyanoacrylic acid portion of the dye. Angle-resolved NEXAFS spectra are fitted to determine the orientation of these two orbital systems, and the results indicate an upright orientation of the adsorbed dye, 63 from the TiO2 surface plane. These experimental results are then compared to computational studies of the WN1 dye on an anatase (101) TiO2 slab. The ground state structure obtained from standard DFT optimization is less upright (45 from the surface) than the NEXAFS results. However, DFT-MD simulations, which provide a more realistic depiction of the dye at room temperature, exhibit excellent agreement - within 2 on average - with the angles determined via NEXAFS, demonstrating the importance of accounting for the dynamic nature of adsorbate-substrate interactions and DFT-MD's powerful predictive abilities. © 2013 American Chemical Society.

Thinning Hair and Hair Loss: Could it be Female Pattern Hair Loss?

Science.gov (United States)

... mcat1=de12", ]; for (var c = 0; c Thinning hair and hair loss: Could it be female pattern hair loss? Female pattern hair loss: Without treatment, female ... can I tell if I have female pattern hair loss? It’s best to make an appointment to ...

PERSULFATE ACTIVATION BY A NATURAL IRON OXIDE FOR THE REMEDIATION OF DYE CONTAMINATION

Directory of Open Access Journals (Sweden)

Sihem BELAIDI

2017-12-01

Full Text Available The objective of this work was to evaluate the removal of crystal violet (CV, a cationic dye, using sodium persulfate (PS as an oxidant in the presence of a natural iron oxide (NIO. Experimental results indicate that approximately 89 % and 98% of CV removal was achieved by PS alone and by (PS/NIO system respectively after 1 hour of reaction. Persulfate oxidation activated with soluble Fe (II enhanced the kinetic oxidation of CV. The increase in the removal extent is due to the adsorption of CV onto NIO surface and to the increased formation of either SO4•- or •OH radicals. The effect of pH on the degradation of CV by PS/NIO was studied. Persulfate degradation increases with a reduction in pH causing increased rate of degradation of organic contaminants. An additional factor in the NIO/PS/UV process is the photolysis of PS which produce two sulfate radicals (SO4•-. Results of this study suggest that NIO can be used as iron source to activate persulfate oxidation.

Adsorption of the diazo dye Direct Red 23 onto a zinc oxide surface: A spectroscopic study

Science.gov (United States)

Lucilha, Adriana Campano; Bonancêa, Carlos Eduardo; Barreto, Wagner José; Takashima, Keiko

2010-01-01

The adsorption of the diazo dye Direct Red 23 onto a zinc oxide surface at 30 °C in the dark was investigated. The color reduction was monitored by spectrophotometry at 503 nm. The FTIR and Raman spectra of the Direct Red 23 adsorption as a function of ZnO concentration were registered. From the PM3 semi-empirical calculations of the atomic charge density and dipole moment of the Direct Red 23 molecule, it was demonstrated that the azo dye molecule may be adsorbed onto the ZnO surface through molecule geometry modifications, enhancing the interfacial area causing a variation in the bonding frequencies.

Anthocyanin – Rich Red Dye of Hibiscus Sabdariffa Calyx Modulates Cisplatin-induced Nephrotoxicity and Oxidative Stress in Rats

Science.gov (United States)

Ademiluyi, Adedayo O.; Oboh, Ganiyu; Agbebi, Oluwaseun J.; Akinyemi, Ayodele J.

2013-01-01

This study sought to investigate the protective effect of dietary inclusion of Hibiscus sabdariffa calyx red dye on cisplatin-induced nephrotoxicity and antioxidant status in rats. Adult male rats were randomly divided into four groups of six animals each. Groups I and II were fed basal diet while groups III and IV were fed diets containing 0.5% and 1% of the dye respectively for 20 days prior to cisplatin administration. Nephrotoxicity was induced by a single dose intraperitoneal administration of cisplatin (7 mg/kg b.w) and the experiment was terminated 3 days after. The kidney and plasma were studied for nephrotoxicity and oxidative stress indices. Cisplatin administration caused a significant (Psabdariffa dye could be attributed to its anthocyanin content. PMID:24711761

Solar photoassisted advanced oxidation process of azo dyes.

Science.gov (United States)

Prato-Garcia, D; Buitrón, G

2009-01-01

Advanced oxidation processes assisted with natural solar radiation in CPC type reactors (parabolic collector compound), was applied for the degradation of three azo dyes: acid orange (AO7), acid red 151 (AR151) and acid blue 113 (AB113). Fenton, Fenton like and ferrioxalate-type complexes showed to be effective for degrade the azo linkage and moieties in different extensions. Initially, the best dose of reagents (Fe(3 + )-H(2)O(2)) was determined through a factorial experimental design, next, using response surface methodologies, the reagent consumption was reduced up to 40%, maintaining in all cases high decolourisation percentages (>98%) after 60 min. of phototreatment. In this work, it was also studied the effect of concentration changes of the influent between 100-300 mg/L and the operation of the photocatalytic process near neutral conditions (pH 6.0-6.5) by using ferrioxalate type complex (FeOx).

An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment.

Science.gov (United States)

Aravind, Priyadharshini; Selvaraj, Hosimin; Ferro, Sergio; Sundaram, Maruthamuthu

2016-11-15

A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO2-RuO2-TiO2 anodes), lead to discoloration by 92% and 89%, respectively, in 100min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition. Results show that the electrochemical discoloration enhances the effluent biodegradability with about 90% COD removal employing acclimatized naphthalene-degrading bacterial consortia, within 144h. Based on results obtained through FT-IR and GC-MS, it is likely that azo group stripping and oxidative cleavage of dyes occur due to the nucleophilic attack of active chlorine species during electro-oxidation. This leads to generation of aromatic intermediates which are further desulfonated, deaminated or oxidized only at their functional groups. These aromatic intermediates were mineralized into simpler organic acids and aldehydes by bacterial consortia. Phyto-toxicity trials on Vigna radiata confirmed the toxic nature of the untreated dye solutions. An increase in root and shoot development was observed with the electrochemically treated solutions, the same was higher in case of bio-treated solutions. Overall, obtained results confirm the capability of the proposed hybrid oxidation scheme for the remediation of textile wastewater. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of Ionic Liquid on the Determination of Aromatic Amines as Contaminants in Hair Dyes by Liquid Chromatography Coupled to Electrochemical Detection

Directory of Open Access Journals (Sweden)

Maria Valnice Boldrin Zanoni

2012-07-01

Full Text Available The room temperature ionic liquid (IL 1-butyl-3-methylimidazolium bis-(trifluorometanesulfonylimide BMIm[NTf₂] was used as a novel medium for improvement of separation and quantization of 16 aromatic amines typically present as contaminants in consumer products and detected by HPLC coupled to an electrochemical detector. The aromatic amines, namely 4,4'-diaminodiphenylmethane, 4-chloroaniline, 2-methoxy-5-methyl-aniline, 3,3'-dimethylbenzidine, 2,4-diaminotoluidine, 2-chloro-4-nitroaniline, 4,4'-oxydianiline, aniline, 3,3'-dichlorobenzidine, benzidine, 4-aminobiphenyl, o-dianisidine, o-anisidine, o-toluidine, 4,4'-methylene-bis-2-chloroaniline and 2-naphthyl-amine are oxidized in methanol/BMIm[NTf₂] at a potential around +0.68V to +0.93V vs. Ag/AgCl at a glassy carbon electrode, which is the base for their determination by HPLC/ED. Using the optimized conditions of methanol/BMIm[NTf₂] 70:30 (v/v as mobile phase, flow-rate of 0.8 mL·min⁻¹, column CLC-ODS, E_ap = +1.0 V and T = 40 °C analytical curves were constructed for each of the tested amines. Good linearity was obtained in the concentration range of 1.09 mg·L⁻¹ to 217 mg·L⁻¹, with excellent correlation coefficients. The limits of detection reached 0.021 mg·L⁻¹ to 0.246 mg·L⁻¹ and good relative standard deviations (RSD, n = 3 were obtained from the measurements. Satisfactory recovery for each aromatic amine was achieved, ranging from 95 to 103%. The developed method was successfully applied to determine six aromatic amines present as contaminants in commercial hair dye samples.

Hydrogen production and metal-dye bioremoval by a Nostoc linckia strain isolated from textile mill oxidation pond.

Science.gov (United States)

Mona, Sharma; Kaushik, Anubha; Kaushik, C P

2011-02-01

Biohydrogen production by Nostoc linckia HA-46, isolated from a textile-industry oxidation-pond was studied by varying light/dark period, pH, temperature and ratio of carbon-dioxide and argon in the gas-mixture. Hydrogen production rates were maximum under 18 h of light and 6 h of darkness, pH 8.0, 31°C, a CO(2):Ar ratio 2:10. Hydrogen production of the strain acclimatized to 20 mg/L of chromium/cobalt and 100 mg/L of Reactive red 198/crystal violet dye studied in N-supplemented/deficient medium was 6-10% higher in the presence of 1.5 g/L of NaNO(3). Rates of hydrogen production in the presence of dyes/metals by the strain (93-105 μmol/h/mg Chlorophyll) were significantly higher than in medium without metals/dyes serving as control (91.3 μmol/h/mg Chlorophyll). About 58-60% of the two metals and 35-73% of dyes were removed by cyanobacterium. Optimal conditions of temperature, pH and metals/dyes concentration for achieving high hydrogen production and wastewater treatment were found practically applicable as similar conditions are found in the effluent of regional textile-mills. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effect of Mixing Dyes and Solvent in Electrolyte Toward Characterization of Dye Sensitized Solar Cell Using Natural Dyes as The Sensitizer

Science.gov (United States)

Puspitasari, Nurrisma; Nurul Amalia, Silviyanti S.; Yudoyono, Gatut; Endarko

2017-07-01

Dye Sensitized Solar Cell (DSSC) using natural dyes (chlorophyll, curcumin from turmeric extract, and anthocyanin from mangosteen extract) have been successfully fabricated for determining the effect of variation natural dyes, mixing dyes and acetonitrile in electrolyte toward characterization of DSSC. DSSC consists of five parts namely ITO (Indium Tin Oxide) as a substrate; TiO2 as semiconductor materials; natural dyes as an electron donor; electrolyte as electron transfer; and carbon as a catalyst that can convert light energy into electric energy. Two types of gel electrolyte based on PEG that mixed with liquid electrolyte have utilized for analyzing the lifetime of DSSC. Type I used distilled water as a solvent whilst type II used acetonitrile as a solvent with addition of concentration of KI and iodine. The main purpose of study was to investigate influence of solvent in electrolyte, variation of natural dyes and mixing dyes toward an efficiency that resulted by DSSC. The result showed that electrolyte type II is generally better than type I with efficiency 0,0556 and 0,0456 %, respectively. An efficiency values which resulted from a variation of mixed three natural dyes showed the greatest efficiency compared to mixed two natural dyes and one dye, with an efficiency value can be achieved at 0,0194 % for chlorophyll; 0,111 % for turmeric; 0,0105 % for mangosteen; 0,0244% (mangosteen and chlorophyll); 0,0117 % (turmeric and mangosteen); 0,0158 % (turmeric and chlorophyll); and 0.0566 % (mixed three natural dyes).

Influence of styryl dyes on blood erythrocytes

Science.gov (United States)

Nizomov, Negmat; Barakaeva, Mubaro; Kurtaliev, Eldar N.; Rahimov, Sherzod I.; Khakimova, Dilorom P.; Khodjayev, Gayrat; Yashchuk, Valeriy N.

2008-08-01

It was studied the influence of F, Sbt, Sil, Sbo monomer and homodimer Dst-5, Dst-10, Dbt-5, Dbt-10, Dil-10, Dbo-10 styryl dyes on blood erythrocytes of white rats. It was shown that the homodimer styryl dyes Dst-5, Dbt-5 and Dbo-10 decrease the erythrocytes quantity by 1.5-2 times more as compared with monomer dyes Sbt and Sbo. The main cause of dyes different action is the different oxidation degree of intracellular hemoglobin evoked by these dyes. It was established that the observed effects was connected with different penetration of these dyes through membrane of erythrocytes and with interaction of these dyes with albumin localized in membranes of cells.

Ferroelectric BiFeO3as an Oxide Dye in Highly Tunable Mesoporous All-Oxide Photovoltaic Heterojunctions

KAUST Repository

Wang, Lingfei

2016-10-12

As potential photovoltaic materials, transition-metal oxides such as BiFeO3 (BFO) are capable of absorbing a substantial portion of solar light and incorporating ferroic orders into solar cells with enhanced performance. But the photovoltaic application of BFO has been hindered by low energy-conversion efficiency due to poor carrier transport and collection. In this work, a new approach of utilizing BFO as a light-absorbing sensitizer is developed to interface with charge-transporting TiO2 nanoparticles. This mesoporous all-oxide architecture, similar to that of dye-sensitized solar cells, can effectively facilitate the extraction of photocarriers. Under the standard AM1.5 (100 mW cm−2) irradiation, the optimized cell shows an open-circuit voltage of 0.67 V, which can be enhanced to 1.0 V by tailoring the bias history. A fill factor of 55% is achieved, which is much higher than those in previous reports on BFO-based photovoltaic devices. The results provide here a new viable approach toward developing highly tunable and stable photovoltaic devices based on ferroelectric transition-metal oxides.

REMOVAL OF ORGANIC DYES FROM CONTAMINATED WATER USING COFE2O4 /REDUCED GRAPHENE OXIDE NANOCOMPOSITE

Directory of Open Access Journals (Sweden)

F. Sakhaei

2016-12-01

Full Text Available Up to now, lots of materials such as active carbon, iron, manganese, zirconium, and metal oxides have been widely used for removal of dyes from contaminated water. Among these, ferrite nanoparticle is an interesting magnetic material due to its moderate saturation magnetization, excellent chemical stability and mechanical hardness. Graphene, a new class of 2D carbonaceous material with atom thick layer features, has attracted much attention recently due to its high specific surface area. Reduced graphene oxide (rGO has also been of great interest because of its unique properties, which are similar to those of graphene, such as specific surface area, making it an ideal candidate for dye removal. Thus far, few works have been carried out on the preparation of CoFe2O4-rGO composite and its applications in removal of contaminants from water. In this paper, CoFe2O4 reduced graphene oxide nanocomposite was fabricated using hydrothermal process. During the hydrothermal process, the reduction of graphene oxide and growth of CoFe2O4 simultaneously occurred on the carbon basal planes under the conditions generated in the hydrothermal system. The samples were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and Fourier transform infrared spectroscopy contaminant and UV-Vis spectroscopy as the analytical method. The experimental results suggest that this material has great potential for treating Congo red contaminated water.

Application of electrochemical advanced oxidation processes with a boron-doped diamond anode to degrade acidic solutions of Reactive Blue 15 (Turqueoise Blue) dye

International Nuclear Information System (INIS)

Solano, Aline Maria Sales; Martínez-Huitle, Carlos Alberto; Garcia-Segura, Sergi; El-Ghenymy, Abdellatif

2016-01-01

Highlights: • Degradation of Reactive Blue 15 solution at pH 3.0 by electrochemical oxidation, electro-Fenton and photoelectro-Fenton. • Hard destruction of the dye and its products by BDD(·OH) and much more rapidly by ·OH. • 94% mineralization by the most powerful photoelectro-Fenton at 66.7 mA cm"−"2, with acetic acid accumulation. • 25 aromatics and heteroaromatics, 30 hydroxylated derivatives and 4 carboxylic acids as products. • Release of Cl"−, SO_4"2"− and pre-eminently NO_3"− during dye mineralization. - Abstract: The degradation of the copper-phthalocyanine dye Reactive Blue 15 dye in sulfate medium has been comparatively studied by electrochemical oxidation with electrogenerated H_2O_2 (EO-H_2O_2), electro-Fenton (EF) and photoelectro-Fenton (PEF). Experiments with 100 cm"3 solutions of 0.203 mmol dm"−"3 dye were performed with a stirred tank reactor containing a boron-doped diamond (BDD) anode and an air-diffusion cathode for continuous H_2O_2 production. Experimental conditions of pH 3.0 and 0.50 mmol dm"−"3 Fe"2"+ as catalyst were found optimal for the EF process by the predominant oxidation with hydroxyl radicals formed in the bulk from Fenton’s reaction between added Fe"2"+ and generated H_2O_2. The kinetics of Reactive Blue 15 abatement was followed by reversed-phase HPLC and always obeyed a pseudo-first-order reaction. The decolorization rate in EO-H_2O_2 was much lower than dye decay due to the formation of large quantities of colored intermediates under the action of hydroxyl radicals generated at the BDD anode from water oxidation. In contrast, the color and dye removals were much more rapid in EF and PEF by the most efficient oxidation of hydroxyl radicals produced from Fenton’s reaction. PEF was the most powerful treatment owing to the photolytic action of UVA irradiation, yielding 94% mineralization after 360 min at 66.7 mA cm"−"2. The effect of current density over the performance of all methods was examined. LC

Charge transfer in graphene oxide-dye system for photonic applications

International Nuclear Information System (INIS)

Bongu, Sudhakara Reddy; Bisht, Prem B.; Thu, Tran V.; Sandhu, Adarsh

2014-01-01

The fluorescence of a standard dye Rhodamine 6G (R6G) in solution decreases on addition of reduced graphene oxide (rGO). The absorption spectra and lifetime measurements confirm that no excited-state but a ground-state complex formation is responsible for this effect. For silver decorated rGO (Ag-rGO), the quenching efficiency and ground state complex formation process is small. Z-scan measurements have been done to study the optical nonlinearity at 532 nm under ps time scale. Remarkable reduction in the saturable absorption (SA) effect of R6G indicates no nonlinear contribution from the ground state complex. The results have been explained with varying charge transfer rates and non-fluorescence nature of the complex

Improvement of the electrochromic response of a low-temperature sintered dye-modified porous electrode using low-resistivity indium tin oxide nanoparticles

International Nuclear Information System (INIS)

Watanabe, Yuichi; Suemori, Kouji; Hoshino, Satoshi

2016-01-01

An indium tin oxide (ITO) nanoparticle-based porous electrode sintered at low temperatures was investigated as a transparent electrode for electrochromic displays (ECDs). The electrochromic (EC) response of the dye-modified ITO porous electrode sintered at 150 °C, which exhibited a generally low resistivity, was markedly superior to that of a conventional dye-modified TiO 2 porous electrode sintered at the same temperature. Moreover, the EC characteristics of the dye-modified ITO porous electrode sintered at 150 °C were better than those of the high-temperature (450 °C) sintered conventional dye-modified TiO 2 porous electrode. These improvements in the EC characteristics of the dye-modified ITO porous electrode are attributed to its lower resistivity than that of the TiO 2 porous electrodes. In addition to its sufficiently low resistivity attained under the sintering conditions required for flexible ECD applications, the ITO porous film had superior visible-light transparency and dye adsorption capabilities. We conclude that the process temperature, resistivity, optical transmittance, and dye adsorption capability of the ITO porous electrode make it a promising transparent porous electrode for flexible ECD applications.

Bioconjugated graphene oxide hydrogel as an effective adsorbent for cationic dyes removal.

Science.gov (United States)

Soleimani, Khadijeh; Tehrani, Abbas Dadkhah; Adeli, Mohsen

2018-01-01

In this study, graphene oxide - cellulose nanowhiskers nanocomposite hydrogel was easily synthesized through covalent functionalization of cellulose nanowhiskers with graphene oxide via a facile approach. The nitrene chemistry applied for covalent functionalization of graphene oxide sheets. The surface morphology and chemical structure of the nanocomposite hydrogel were characterized by FTIR, TGA, Raman, XRD, elemental analysis and SEM. The UV/Visible absorption spectrum revealed that the obtained porous nanocomposite hydrogel can efficiently remove cationic dyes such as methylene blue (MB) and Rhodamine B (RhB) from wastewater with high absorption power. The adsorption process showed that 100% of MB and 90% of RhB have been removed and the equilibrium state has been reached in 15min for low concentration solutions in accordance with the pseudo-second-order model. Moreover, the sample exhibited stable performance after being used several times. High adsorption capacity and easy recovery are the efficient factors making these materials as good adsorbent for water pollutants and wastewater treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

Anodic oxidation of anthraquinone dye Alizarin Red S at Ti/BDD electrodes

Energy Technology Data Exchange (ETDEWEB)

Sun Jianrui; Lu Haiyan [College of Chemistry, Jilin University, Changchun 130012 (China); Du Lili [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Lin Haibo, E-mail: lhb910@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China); State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China); Li Hongdong, E-mail: hdli@jlu.edu.cn [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China)

2011-05-15

The boron-doped diamond (BDD) thin-film electrode with high quality using industrially titanium plate (Ti/BDD) as substrate has been prepared and firstly used in the oxidation of anthraquinone dye Alizarin Red S (ARS) in wastewaters. The Ti/BDD electrodes are shown to have high concentration of sp{sup 3}-bonded carbon and wide electrochemical window. The results of the cyclic voltammetries show that BDD has unique properties such as high anodic stability and the production of active intermediates at the high potential. The oxidation regions of ARS and water are significantly separated at the Ti/BDD electrode, and the peak current increases linearly with increasing ARS concentration. The bulk electrolysis shows that removal of chemical oxygen demand (COD) and color can be completely reached and the electrooxidation of ARS behaves as a mass-transfer-controlled process at the Ti/BDD electrode. It is demonstrated that the performances of the Ti/BDD electrode for anodic oxidation ARS have been significantly improved with respect to the traditional electrodes.

Photoelectrochemical characterization of squaraine-sensitized nickel oxide cathodes deposited via screen-printing for p-type dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Naponiello, Gaia; Venditti, Iole [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Zardetto, Valerio [Centre for Hybrid and Organic Solar Energy, Department of Electronic Engineering, University of Rome - Tor Vergata, via del Politecnico 1, 00133 Rome (Italy); Saccone, Davide [Department of Chemistry and NIS, Interdepartmental Centre of Excellence, University of Torino, via Pietro Giuria 7, I-10125 Torino (Italy); Di Carlo, Aldo [Centre for Hybrid and Organic Solar Energy, Department of Electronic Engineering, University of Rome - Tor Vergata, via del Politecnico 1, 00133 Rome (Italy); Fratoddi, Ilaria [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Center for Nanotechnology for Engineering (CNIS), Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Barolo, Claudia [Department of Chemistry and NIS, Interdepartmental Centre of Excellence, University of Torino, via Pietro Giuria 7, I-10125 Torino (Italy); Dini, Danilo, E-mail: danilo.dini@uniroma1.it [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy)

2015-11-30

Graphical abstract: Screen-printing method has been adopted for the deposition of nickel oxide thin film electrodes with mesoporous features. Nickel oxide was sensitized with three newly synthesized squaraines (VG1C8,VG10C8 and DS2/35) and employed as photoelectroactive cathode of p-type dye-sensitized solar cells. Colorant erythrosine b (EB) was taken as commercial benchmark for comparative purposes. Sensitization was successful with the attainment of overall conversion efficiencies in the order of 0.025% when the mesoporous surface of nickel oxide was alkali treated. The prolongation of nickel oxide sensitization time up to 16 h led to a general increase of the open circuit voltage in the corresponding solar cells. - Highlights: • We deposited nickel oxide with screen-printing technique utilizing nickel oxide nanoparticles. • We employed screen-printed nickel oxide as cathodes of p-DSCs. • We employed new squaraine as sensitizers of screen-printed nickel oxide. • Further progress is expected when the formulation of the screen-printing paste will be optimized. - Abstract: In the present paper we report on the employment of the screen-printing method for the deposition of nickel oxide (NiO{sub x}) layers when preformed nanoparticles of the metal oxide (diameter < 50 nm) constitute the precursors in the paste. The applicative purpose of this study is the deposition of mesoporous NiO{sub x} electrodes in the configuration of thin films (thickness, l ≤ 4 μm) for the realization of p-type dye-sensitized solar cells (p-DSCs). Three different squaraine-based dyes (here indicated with VG1C8, VG10C8 and DS2/35), have been used for the first time as sensitizers of a p-type DSC electrode. VG1C8 and VG10C8 present two carboxylic groups as anchoring moieties, whereas DS2/35 sensitizer possesses four acidic anchoring groups. All three squaraines are symmetrical and differ mainly for the extent of electronic conjugation. The colorant erythrosine b (ERY B) was taken as

Body hair transplant: An additional source of donor hair in hair restoration surgery

Directory of Open Access Journals (Sweden)

Poswal Arvind

2007-01-01

Full Text Available Androgenic alopecia (pattern baldness is a condition in which there is androgen mediated progressive miniaturization and loss of hair follicles in a genetically susceptible individual. A 47-year-old male patient with advanced degree of hair loss (Norwood 6 category wanted to go for full hair restoration surgery. Due to the limited availability of donor hair in the scalp, a small session with 700-chest hair was performed. On follow-up at eight months it was observed that chest hair grew and formed a cosmetically acceptable forelock.

Triphenylamine based organic dyes for dye sensitized solar cells: A theoretical approach

Energy Technology Data Exchange (ETDEWEB)

Mohankumar, V.; Pandian, Muthu Senthil; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [SSN Research Centre, SSN College of Engineering, Chennai-603110, Tamilnadu (India)

2016-05-23

The geometry, electronic structure and absorption spectra for newly designed triphenylamine based organic dyes were investigated by density functional theory (DFT) and time dependent density functional theory (TD-DFT) with the Becke 3-Parameter-Lee-Yang-parr(B3LYP) functional, where the 6-31G(d,p) basis set was employed. All calculations were performed using the Gaussian 09 software package. The calculated HOMO and LUMO energies show that charge transfer occurs in the molecule. Ultraviolet–visible (UV–vis) spectrum was simulated by TD-DFT in gas phase. The calculation shows that all of the dyes can potentially be good sensitizers for DSSC. The LUMOs are just above the conduction band of TiO{sub 2} and their HOMOs are under the reduction potential energy of the electrolytes (I{sup −}/I{sub 3}{sup −}) which can facilitate electron transfer from the excited dye to TiO{sub 2} and charge regeneration process after photo oxidation respectively. The simulated absorption spectrum of dyes match with solar spectrum. Frontier molecular orbital results show that among all the three dyes, the “dye 3” can be used as potential sensitizer for DSSC.

Dye sensitized solar cells. How do they work?

International Nuclear Information System (INIS)

Laurie M, Peter

2008-01-01

Dye sensitized solar cells (DSC), also known as Gratzel cells, harvest sunlight using a dye adsorbed onto the high surface area of a porous nanocrystalline titanium dioxide film. Photoexcitation of the dye results in the injection of electrons into the conduction band of the oxide. The dye is regenerated in its original state by donation of electrons from iodide ions presenting an electrolyte that permeates the porous oxide film. The regeneration cycle is completed at a platinum coated cathode at which tri-iodide ions are reduced to iodide ions. DSC has achieved solar conversion efficiencies of over 10% in the laboratory, with best module efficiencies of around 8%. This lecture will describe the fabrication of the basic DSC and discuss the basic Physics and Chemistry of the cell. (Full text)

Photo catalytic Degradation of Organic Dye by Sol-Gel-Derived Gallium-Doped Anatase Titanium Oxide Nanoparticles for Environmental Remediation

International Nuclear Information System (INIS)

Arghya, N.B.; Sang, W.J.; Bong-Ki, M.

2012-01-01

Photo catalytic degradation of toxic organic chemicals is considered to be the most efficient green method for surface water treatment. We have reported the sol-gel synthesis of Gadoped anatase TiO 2 nanoparticles and the photo catalytic oxidation of organic dye into nontoxic inorganic products under UV irradiation. Photodegradation experiments show very good photo catalytic activity of Ga-doped TiO 2 nanoparticles with almost 90% degradation efficiency within 3 hrs of UV irradiation, which is faster than the undoped samples. Doping levels created within the bandgap of TiO 2 act as trapping centers to suppress the photo generated electron-hole recombination for proper and timely utilization of charge carriers for the generation of strong oxidizing radicals to degrade the organic dye. Photo catalytic degradation is found to follow the pseudo-first-order kinetics with the apparent 1 st-order rate constant around 1.3 x 10 -2 min -1 . The cost-effective, sol-gel-derived TiO 2 : Ga nanoparticles can be used efficiently for light-assisted oxidation of toxic organic molecules in the surface water for environmental remediation.

Synthesis of Nickel Oxide Nanoparticles Using Gelatine as a Green Template for Photocatalytic Degradation of Dye

OpenAIRE

JAY YANG LEE

2018-01-01

Nickel oxide (NiO) nanoparticles were synthesized through sol-gel method with an environmentally friendly templating agent, which is gelatin. The synthesized NiO were characterized to determine the chemical and physical properties of the nanoparticles. The optimum synthesis parameters were used in photocatalytic degradation of Reactive Black 5 and Acid Yellow 25 dye to determine the catalytic activity of the nanoparticles.

Body Hair

Science.gov (United States)

... girlshealth.gov/ Home Body Puberty Body hair Body hair Even before you get your first period , you ... removing pubic hair Ways to get rid of hair top Removing body hair can cause skin irritation, ...

Nanoporous of W/WO{sub 3} thin film electrode grown by electrochemical anodization applied in the photoelectrocatalytic oxidation of the basic red 51 used in hair dye

Energy Technology Data Exchange (ETDEWEB)

Fraga, Luciano E.; Zanoni, Maria Valnice B., E-mail: fraga@iq.unesp.b [Universidade Estadual Paulista (IQ/UNESP), Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

2011-07-01

Self-organized W/WO{sub 3} nanoporous electrodes can be obtained by simple electrochemical anodization of W foil in 0.15 mol L{sup -1} NaF solution as the supporting electrolyte, applying a ramp potential of 0.2 V s{sup -1} until it reached 60 V, which was maintained for 2 h. The monoclinic form is majority in the highly ordered WO{sub 3} annealed at 450 deg C, obtaining a higher photoactivity when irradiated by visible light than by UV light. The electrode promotes complete discoloration of the investigated basic red 51 dye after 60 min of photoelectrocatalytic oxidation, on current density of 1.25 mA cm{sup -2} and irradiation on wavelength of 420-630 nm. In this condition it was obtained 63% of mineralization. Lower efficiency is obtained for the system irradiated by wavelength (280- 400 nm) when only 40% of total organic carbon removal is obtained and 120 min is required for complete discoloration. (author)

Optimization of the C11-BODIPY581/591 Dye for the Determination of Lipid Oxidation in Chlamydomonas reinhardtii by Flow Cytometry

OpenAIRE

CHELONI Giulia

2013-01-01

Lipid oxidation is a recognized end point for the study of oxidative stress and is an important parameter to describe the mode of micropollutant action on aquatic microorganisms. Therefore the development of quick and reliable methodologies probing the oxidative stress and damage in living cells is highly sought. In the present proof of concept work we examined the potential of the fluorescent dye C11 BODIPY591/581 to probe lipid oxidation in the green microalga Chlamydomonas reinhardtii. C11...

Ferroelectric BiFeO3 as an Oxide Dye in Highly Tunable Mesoporous All-Oxide Photovoltaic Heterojunctions.

Science.gov (United States)

Wang, Lingfei; Ma, He; Chang, Lei; Ma, Chun; Yuan, Guoliang; Wang, Junling; Wu, Tom

2017-01-01

As potential photovoltaic materials, transition-metal oxides such as BiFeO 3 (BFO) are capable of absorbing a substantial portion of solar light and incorporating ferroic orders into solar cells with enhanced performance. But the photovoltaic application of BFO has been hindered by low energy-conversion efficiency due to poor carrier transport and collection. In this work, a new approach of utilizing BFO as a light-absorbing sensitizer is developed to interface with charge-transporting TiO 2 nanoparticles. This mesoporous all-oxide architecture, similar to that of dye-sensitized solar cells, can effectively facilitate the extraction of photocarriers. Under the standard AM1.5 (100 mW cm -2 ) irradiation, the optimized cell shows an open-circuit voltage of 0.67 V, which can be enhanced to 1.0 V by tailoring the bias history. A fill factor of 55% is achieved, which is much higher than those in previous reports on BFO-based photovoltaic devices. The results provide here a new viable approach toward developing highly tunable and stable photovoltaic devices based on ferroelectric transition-metal oxides. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sonochemical co-deposition of antibacterial nanoparticles and dyes on textiles

Directory of Open Access Journals (Sweden)

Ilana Perelshtein

2016-01-01

Full Text Available The sonochemical technique has already been proven as one of the best coating methods for stable functionalization of substrates over a wide range of applications. Here, we report for the first time on the simultaneous sonochemical dyeing and coating of textiles with antibacterial metal oxide (MO nanoparticles. In this one-step process the antibacterial nanoparticles are synthesized in situ and deposited together with dye nanoparticles on the fabric surface. It was shown that the antibacterial behavior of the metal oxides was not influenced by the presence of the dyes. Higher K/S values were achieved by sonochemical deposition of the dyes in comparison to a dip-coating (exhaustion process. The stability of the antibacterial properties and the dye fastness was studied for 72 h in saline solution aiming at medical applications.

Ingrown Hair

Science.gov (United States)

Ingrown hair Overview An ingrown hair occurs when a shaved or tweezed hair grows back into the skin. It can cause inflammation, pain and tiny bumps in the area where the hair was removed. Ingrown hair is a common condition ...

Numerical simulation of the hair formation -modeling of hair cycle

Science.gov (United States)

Kajihara, Narumichi; Nagayama, Katsuya

2018-01-01

In the recent years, the fields of study of anti-aging, health and beauty, cosmetics, and hair diseases have attracted significant attention. In particular, human hair is considered to be an important aspect with regard to an attractive appearance. To this end, many workers have sought to understand the formation mechanism of the hair root. However, observing growth in the hair root is difficult, and a detailed mechanism of the process has not yet been elucidated. Hair repeats growth, retraction, and pause cycles (hair cycle) in a repetitive process. In the growth phase, hair is formed through processes of cell proliferation and differentiation (keratinization). During the retraction phase, hair growth stops, and during the resting period, hair fall occurs and new hair grows. This hair cycle is believed to affect the elongation rate, thickness, strength, and shape of hair. Therefore, in this study, we introduce a particle model as a new method to elucidate the unknown process of hair formation, and to model the hair formation process accompanying the proliferation and differentiation of the hair root cells in all three dimensions. In addition, to the growth period, the retraction and the resting periods are introduced to realize the hair cycle using this model.

TiO2/Ag modified penta-bismuth hepta-oxide nitrate and its adsorption performance for azo dye removal

Institute of Scientific and Technical Information of China (English)

Eshraq Ahmed Abdullah; Abdul Halim Abdullah; Zulkarnain Zainal; Mohd Zobir Hussein; Tan Kar Ban

2012-01-01

A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi5O7NO3) surface was synthesized via a precipitation method using TiO2 and Ag as modified agents.The synthesized product was characterized by different analytical techniques.The removal efficiency was evaluated using mono- and di-sulphonated azo dyes as model pollutants.Different kinetic,isotherm and diffusion models were chosen to describe the adsorption process.X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi5O7NO3; however,the presence of hydrophilic centres such as TiO2 and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes.Dyes removal was found to be a function of adsorbent dosage,initial dye concentration,solution pH and temperature.The reduction of Langrnuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent.Mass transfer can be described by intra-particle diffusion at a certain stage,but it was not the rate limiting step that controlled the adsorption process.Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.

Trace element determination study in human hair by neutron activation analysis

International Nuclear Information System (INIS)

Frazao, Selma Violato

2008-01-01

showed that element adsorption or desorption occurs due to the dye. Analysis of hair samples collected from different regions of the head presented significant differences for the elements Fe, Sc, Se and Cr, indicating the importance of defining head regions for hair sample collection. Results of hair analysis from individuals residing in Sao Paulo metropolitan area showed individual differences for age, gender and natural hair color. Results obtained in this population also showed, that the mean element concentrations found are within the literature values. (author)

Photocatalytic discoloration of reactive blue 5g dye in the presence of mixed oxides and with the addition of iron and silver

International Nuclear Information System (INIS)

Souza, M.C.P; Lenzi, G.G.; Jorge, L.M.M.; Santos, O.A.A.; Colpini, L.M.S.

2011-01-01

This work reports the use of cerium-titania-alumina-based systems modified with Ag and Fe by the wetness impregnation method for the discoloration of blue 5G dye. The techniques employed to characterize the photocatalysts were: temperature-programmed reduction (TPR), X-ray diffraction (XRD), specific surface area, average pore volume, and average pore diameter. The characterization results indicated that the photocatalysts had different crystalline structures and textural properties. Discoloration with the mixed oxide photocatalyst CeO 2 -TiO 2 -Al 2 O 3 gave a result similar to that of TiO 2 . On the other hand, the addition of Ag and Fe to the mixed oxide increased the discoloration and reaction rates of reactive blue 5G dyes. (author)

Photocatalytic discoloration of reactive blue 5g dye in the presence of mixed oxides and with the addition of iron and silver

Energy Technology Data Exchange (ETDEWEB)

Souza, M.C.P; Lenzi, G.G.; Jorge, L.M.M.; Santos, O.A.A. [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Engenharia Quimica; Colpini, L.M.S. [Universidade Federal do Parana (UFPR), Palotina, PR (Brazil). Curso Superior de Tecnologia em Biocombustiveis

2011-07-15

This work reports the use of cerium-titania-alumina-based systems modified with Ag and Fe by the wetness impregnation method for the discoloration of blue 5G dye. The techniques employed to characterize the photocatalysts were: temperature-programmed reduction (TPR), X-ray diffraction (XRD), specific surface area, average pore volume, and average pore diameter. The characterization results indicated that the photocatalysts had different crystalline structures and textural properties. Discoloration with the mixed oxide photocatalyst CeO{sub 2}-TiO{sub 2}-Al{sub 2}O{sub 3} gave a result similar to that of TiO{sub 2}. On the other hand, the addition of Ag and Fe to the mixed oxide increased the discoloration and reaction rates of reactive blue 5G dyes. (author)

Anodic oxidation of wastewater containing the Reactive Orange 16 Dye using heavily boron-doped diamond electrodes

International Nuclear Information System (INIS)

Migliorini, F.L.; Braga, N.A.; Alves, S.A.; Lanza, M.R.V.; Baldan, M.R.; Ferreira, N.G.

2011-01-01

Highlights: → Electrochemical advanced oxidation process was studied using BDD based anodes with different boron concentrations. → The difference between the non-active and active anodes for organics degradation. → The influence of morphologic and structural properties of BDD electrodes on the RO-16 dye degradation. - Abstract: Boron-doped diamond (BDD) films grown on the titanium substrate were used to study the electrochemical degradation of Reactive Orange (RO) 16 Dye. The films were produced by hot filament chemical vapor deposition (HFCVD) technique using two different boron concentrations. The growth parameters were controlled to obtain heavily doped diamond films. They were named as E1 and E2 electrodes, with acceptor concentrations of 4.0 and 8.0 x 10 21 atoms cm -3 , respectively. The boron levels were evaluated from Mott-Schottky plots also corroborated by Raman's spectra, which characterized the film quality as well as its physical property. Scanning Electron Microscopy showed well-defined microcrystalline grain morphologies with crystal orientation mixtures of (1 1 1) and (1 0 0). The electrode efficiencies were studied from the advanced oxidation process (AOP) to degrade electrochemically the Reactive Orange 16 azo-dye (RO16). The results were analyzed by UV/VIS spectroscopy, total organic carbon (TOC) and high-performance liquid chromatography (HPLC) techniques. From UV/VIS spectra the highest doped electrode (E2) showed the best efficiency for both, the aromaticity reduction and the azo group fracture. These tendencies were confirmed by the TOC and chromatographic measurements. Besides, the results showed a direct relationship among the BDD morphology, physical property, and its performance during the degradation process.

Hair Transplants

Science.gov (United States)

... Search Skin Experts Skin Treatments Hair Transplants Share » HAIR TRANSPLANTS Before (left) and after (right) - front of ... transplant. Photo courtesy of N. Sadick What are hair transplants? In punch transplanting, a plug containing hair ...

Electrochemical reduction and oxidation pathways for Reactive Black 5 dye using nickel electrodes in divided and undivided cells

International Nuclear Information System (INIS)

Méndez-Martínez, Ana J.; Dávila-Jiménez, Martin M.; Ornelas-Dávila, Omar; Elizalde-González, María P.; Arroyo-Abad, Uriel; Sirés, Ignasi; Brillas, Enric

2012-01-01

Highlights: ► Ni electrodes were used for the mild degradation of the azo dye Reactive Black 5. ► Potentiostatic degradation was performed in undivided and divided cells. ► Degradation by-products were detected and monitored by RP-HPLC and LC–MS/MS. ► Small alkylsulfonyl phenol and isoxazole derivatives were identified. ► The cathodic and anodic degradation pathways for Reactive Black 5 were elucidated. - Abstract: The cathodic reduction and anodic ·OH-mediated oxidation of the azo dye Reactive Black 5 (RB5) have been studied potentiostatically by using undivided and divided cells with a Ni-polyvinylchloride (Ni-PVC) composite cathode and a Ni wire mesh anode. Solutions of 50–100 cm 3 of 20–80 mg dm −3 RB5 in 0.1 mol dm −3 KOH were degraded to assess the effect of electrolysis time and electrode potentials on the infrared and absorbance spectra, as well as on the decay of the total organic carbon and chemical oxygen demand. Reversed-phase high performance liquid chromatography (RP-HPLC) with ion-pairing and diode array detection (ion pair chromatography), along with coupling to tandem mass spectrometry (LC–MS/MS), were used for the identification of the aromatic degradation by-products and monitoring their time course. These analyses revealed the progressive conversion of the RB5 dye to simpler molecules with m/z 200, 369.5 and 547 under the direct action of the electron at the cathode and the formation of polar compounds such as alkylsulfonyl phenol derivatives with m/z 201, 185 and 171 by the ·OH mediation at the anode. From these results, the electrochemical reduction and oxidation pathways for the RB5 dye were elucidated.

From Hair in India to Hair India.

Science.gov (United States)

Trüeb, Ralph M

2017-01-01

In all cultures, human hair and hairdo have been a powerful metaphor. Tracing back the importance and significance of human hair to the dawn of civilization on the Indian subcontinent, we find that all the Vedic gods are depicted as having uncut hair in mythological stories as well as in legendary pictures. The same is true of the Hindu avatars, and the epic heroes of the Ramayana, and the Mahabharata. Finally, there are a number of hair peculiarities in India pertinent to the creed and religious practices of the Hindu, the Jain, and the Sikh. Shiva Nataraja is a depiction of the Hindu God Shiva as the cosmic dancer who performs his divine dance as creator, preserver, and destroyer of the universe and conveys the Indian conception of the never-ending cycle of time. The same principle manifests in the hair cycle, in which perpetual cycles of growth, regression, and resting underly the growth and shedding of hair. Finally, The Hair Research Society of India was founded as a nonprofit organisation dedicated to research and education in the science of hair. Notably, the HRSI reached milestones in the journey of academic pursuit with the launch of the International Journal of Trichology, and with the establishment of the Hair India conference. Ultimately, the society aims at saving the public from being taken for a ride by quackery, and at creating the awareness that the science of hair represents a subspecialty of Dermatology. In analogy again, the dwarf on which the Nataraja dances represents the demon of egotism, and thus symbolizes Shiva's, respectively, the HRSI's victory over ignorance.

Hair Removal

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Hair Removal KidsHealth / For Teens / Hair Removal What's in ... you need any of them? Different Types of Hair Before removing hair, it helps to know about ...

Your Hair

Science.gov (United States)

... Safe Videos for Educators Search English Español Your Hair KidsHealth / For Kids / Your Hair What's in this ... eyes from sweat dripping down from your forehead. Hair Comes From Where? Whether hair is growing out ...

Hair Removal

DEFF Research Database (Denmark)

Hædersdal, Merete

2011-01-01

Hair removal with optical devices has become a popular mainstream treatment that today is considered the most efficient method for the reduction of unwanted hair. Photothermal destruction of hair follicles constitutes the fundamental concept of hair removal with red and near-infrared wavelengths...... suitable for targeting follicular and hair shaft melanin: normal mode ruby laser (694 nm), normal mode alexandrite laser (755 nm), pulsed diode lasers (800, 810 nm), long-pulse Nd:YAG laser (1,064 nm), and intense pulsed light (IPL) sources (590-1,200 nm). The ideal patient has thick dark terminal hair......, white skin, and a normal hormonal status. Currently, no method of lifelong permanent hair eradication is available, and it is important that patients have realistic expectations. Substantial evidence has been found for short-term hair removal efficacy of up to 6 months after treatment with the available...

Hair removal

DEFF Research Database (Denmark)

Haedersdal, Merete; Haak, Christina S

2011-01-01

Hair removal with optical devices has become a popular mainstream treatment that today is considered the most efficient method for the reduction of unwanted hair. Photothermal destruction of hair follicles constitutes the fundamental concept of hair removal with red and near-infrared wavelengths...... suitable for targeting follicular and hair shaft melanin: normal mode ruby laser (694 nm), normal mode alexandrite laser (755 nm), pulsed diode lasers (800, 810 nm), long-pulse Nd:YAG laser (1,064 nm), and intense pulsed light (IPL) sources (590-1,200 nm). The ideal patient has thick dark terminal hair......, white skin, and a normal hormonal status. Currently, no method of lifelong permanent hair eradication is available, and it is important that patients have realistic expectations. Substantial evidence has been found for short-term hair removal efficacy of up to 6 months after treatment with the available...

Degradation and ecotoxicity of dye Reactive Black 5 after reductive-oxidative process : Environmental Science and Pollution Research.

Science.gov (United States)

Cuervo Lumbaque, Elisabeth; Gomes, Monike Felipe; Da Silva Carvalho, Vanessa; de Freitas, Adriane Martins; Tiburtius, Elaine Regina Lopes

2017-03-01

This research paper describes the study of a reduction-oxidation system using commercial steel wool (Fe 0 ) and H 2 O 2 for degradation of the dye Reactive Black 5 and aromatic compounds in water. The reductive process alone allowed the almost complete removal of color (97 ± 1 %) after 60 min of reaction. The decrease in spectral area (λ = 599 nm) associated with the chromophore group indicates breakage of the azo bonds. Moreover, the significant change in UV spectra can be associated with the formation of aromatic amines. Regarding the transformation products, a spectrophotometric method based on the diazotization reaction was employed to identify aromatic amines after reductive process, using sulfanilic acid as a model of aromatic amines. In addition, association with Fenton reagents improved the efficiency in the system with 93 ± 1 % degradation of intermediates formed during the reductive process. Ecotoxicological analysis revealed that the dye solution, after the reductive and oxidative processes, was not toxic to Lactuca sativa seeds. For Daphnia magna, the EC 50 (%) values observed revealed that dye solution has an EC 50 (%) = 74.1 and after reductive process, the toxicity increased (EC 50 (%) = 63.5), which might be related to the formation of aromatic amines. However, after the Fenton process, the EC 50 (%) was >100. These results demonstrated that the Fenton reaction using steel wool as an iron source was very efficient to decrease color, aromatic transformation products, and the ecotoxicity of Reactive Black 5 in solution.

Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction.

Science.gov (United States)

Vallet, Ana; Ovejero, Gabriel; Rodríguez, Araceli; Peres, José A; García, Juan

2013-01-15

Active nickel catalysts (7 wt%) supported over Mg-Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min(-1) and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min(-1), respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T(r)=0.098 g(Ni) min mL(-1). After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T(r)=0.098 g(Ni) min mL(-1), attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Degradation of amaranth dye in alkaline medium by ultrasonic cavitation coupled with electrochemical oxidation using a boron-doped diamond anode

International Nuclear Information System (INIS)

Barros, Willyam R.P.; Steter, Juliana R.; Lanza, Marcos R.V.; Motheo, Artur J.

2014-01-01

Amaranth dye is used widely in the processing of paper, textiles, foods, cosmetics, beverages and medicines, and effluents contaminated with this compound are discharged daily into the environment. Recent studies have shown that azo dyes, especially those such as amaranth dye that have been classified as endocrine disruptors, may cause adverse effects to animal and human health. This paper describes the application of electrochemical oxidation (with a boron-doped diamond BDD thin-film anode) coupled with ultrasound sonolysis (20 kHz and 523 W cm −2 ) to the removal of amaranth dye from dilute alkaline solution. The electrochemical and sonoelectrochemical processes (ECh and SECh, respectively) were carried out at constant current density (10 to 50 mA cm −2 ) in a single compartment cylindrical cell. Sonolysis was virtually less useful for the decolorization and degradation of amaranth dye, whilst ECh and SECh were more effective in degrading the dye with almost complete removal (90 - 95%) attained after 90 min of experiment at an applied current density of 50 mA cm −2 . Degradation of the dye followed pseudo first-order kinetics in both processes, but the rate of reaction was faster with the SECh treatment confirming a synergistic effect between the cavitation process and the electrochemical system. Additionally, at low applied current densities (10 and 25 mA cm −2 ), SECh was considerably more effective than ECh for the amaranth dye mineralization. Although at 35 and 50 mA cm −2 , the two processes showed the respective removal of total organic carbon values: (i) 85% for the ECh and 90% for the SECh at 35 mA cm −2 ; (ii) 96% for the ECh and 98% for the SECh at 50 mA cm −2 . It is concluded that SECh presented the most favorable results for the decontamination of wastewaters containing azo dye compounds

Dye adsorption mechanisms in TiO2 films, and their effects on the photodynamic and photovoltaic properties in dye-sensitized solar cells.

Science.gov (United States)

Hwang, Kyung-Jun; Shim, Wang-Geun; Kim, Youngjin; Kim, Gunwoo; Choi, Chulmin; Kang, Sang Ook; Cho, Dae Won

2015-09-14

The adsorption mechanism for the N719 dye on a TiO2 electrode was examined by the kinetic and diffusion models (pseudo-first order, pseudo-second order, and intra-particle diffusion models). Among these methods, the observed adsorption kinetics are well-described using the pseudo-second order model. Moreover, the film diffusion process was the main controlling step of adsorption, which was analysed using a diffusion-based model. The photodynamic properties in dye-sensitized solar cells (DSSCs) were investigated using time-resolved transient absorption techniques. The photodynamics of the oxidized N719 species were shown to be dependent on the adsorption time, and also the adsorbed concentration of N719. The photovoltaic parameters (Jsc, Voc, FF and η) of this DSSC were determined in terms of the dye adsorption amounts. The solar cell performance correlates significantly with charge recombination and dye regeneration dynamics, which are also affected by the dye adsorption amounts. Therefore, the photovoltaic performance of this DSSC can be interpreted in terms of the adsorption kinetics and the photodynamics of oxidized N719.

Optical properties of anthocyanin dyes on TiO2 as photosensitizers for application of dye-sensitized solar cell (DSSC)

Science.gov (United States)

Ahliha, A. H.; Nurosyid, F.; Supriyanto, A.; Kusumaningsih, T.

2018-03-01

Dye-sensitized solar cell (DSSC) is one of the alternative energy that can convert light energy into electrical energy. The component of DSSC consists of FTO substrates, TiO2, electrolyte, dye sensitizer, and counter electrode. This study aim was to determine the effect of optical properties of anthocyanin dyes on efficiency of DSSC. The dye sensitizer used can be extracted from anthocyanin pigments such as dragon fruit, black rice, and red cabbage. The red cabbage sensitizer shows lower absorbance value in the visible range (450-580 nm), than dragon fruit and black rice. The chemical structure of each dye molecules has an R group (carbonyl and hydroxyl) that forms a bond with the oxide layer. Red cabbage dye cell has the highest efficiency, 0.06% then dragon fruit and black rice, 0.02% and 0.03%.

Gold nanoworms immobilized graphene oxide polymer brush nanohybrid for catalytic degradation studies of organic dyes

Science.gov (United States)

Mogha, Navin Kumar; Gosain, Saransh; Masram, Dhanraj T.

2017-02-01

In the present work, we report gold nanoparticles (AuNPs) on poly (dimethylaminoethyl methacrylate) (PDMAEMA) brushes immobilized reduced graphene oxide (Au/PDMAEMA/RGO) as catalyst for degradation kinetic studies of Rhodamine B (RB), Methyl Orange (MO) and Eosine Y (EY) dyes, having an excellent catalytic activity, as evident by the apparent rate constant (kapp), which is found to be 21.8, 26.2, and 8.7 (×10-3 s-1), for RB, MO and EY respectively. Au/PDMAEMA/RGO catalyst is easy to use, highly efficient, recyclable, which make it suitable for applications in waste water management. Foremost, synthesis of PDMAEMA brushes on graphene oxide is accomplished by Atom transfer radical polymerization method (ATRP), whereas AuNPs are synthesized by simple chemical reduction method.

Vanadium oxide (VO) based low cost counter electrode in dye sensitized solar cell (DSSC) applications

Energy Technology Data Exchange (ETDEWEB)

Vijayakumar, P.; Pandian, Muthu Senthil; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [SSN Research Centre, SSN College of Engineering, Kalavakkam-603 110, Chennai, Tamilnadu (India)

2015-06-24

Vanadium oxide nanostars were synthesized by chemical method. The prepared Vanadium oxide nanostars are introduced into dye sensitized solar cell (DSSC) as counter electrode (CE) catalyst to replace the expensive platinum (Pt). The products were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) method. The photovoltaic performance of the VO as counter electrode based DSSC was evaluated under simulated standard global AM 1.5G sunlight (100 mW/cm{sup 2}). The solar to electrical energy conversion efficiency (η) of the DSSC was found to be 0.38%.This work expands the Counter electrode catalyst, which can help to reduce the cost of DSSC and thereby encourage their fundamental research and commercial application.

Chromatographic separation and spectro-analytical characterization of a natural African mineral dye

Directory of Open Access Journals (Sweden)

G.B. Adebayo

2007-08-01

Full Text Available Chromatographic fractionation and spectroscopic characterization of a natural African mineral dye have been carried out. The chromatographic separation of the dyes made use of column and thin layer chromatographic techniques. Some physicochemical properties of the dye including solubility in polar and non-polar solvents, pH, ash and organic contents were determined. The spectro-analytical techniques used for characterization included energy dispersive X-ray fluorescence (EDXRF, X-ray diffractometry (XRD, Optical microscopy, infrared (IR and UV-VIS spectroscopy. Four different fractions having colours yellow, grey, orange and purple were obtained from the chromatographic separation. All the fractions were found to contain aromatic nucleus based on IR and UV-VIS spectroscopic data. Other functional groups detected are Ar-NH2, -CONH2, C=C, C-C and metal-carbon chelate rings. The presence of aromatic amine in the dye provides strong evidence for its use as hair dye. The dye was found to be soluble in both aqueous and non-aqueous solvents. The pH of the dye's aqueous solution was found to be 8.6, and the ash and organic content of the raw dye were 49 % and 51 % respectively. The XRF revealed that the dye contains twenty elements with concentrations ranging from major to ultra-trace levels. The XRD also showed that the sample contains about forty-six mineral phases which include both inorganic and organic components. The maximum absorption wavelength (λmax in UV-VIS of the aqueous solution was found to be 464 nm. The optical microscopic investigation gave indication that the dyes are likely to be of the marine origin.

In-situ electrochemical doping of nanoporous anodic aluminum oxide with indigo carmine organic dye

International Nuclear Information System (INIS)

Stępniowski, Wojciech J.; Norek, Małgorzata; Budner, Bogusław; Michalska-Domańska, Marta; Nowak-Stępniowska, Agata; Bombalska, Aneta; Kaliszewski, Miron; Mostek, Anna; Thorat, Sanjay; Salerno, Marco; Giersig, Michael; Bojar, Zbigniew

2016-01-01

Nanoporous anodic aluminum oxide was formed in sulfuric acid with addition of indigo carmine. During anodizing, the organic dye was incorporated into the porous oxide walls. X-ray photoelectron spectroscopy revealed the presence of nitrogen and sulfur in the anodic aluminum oxide. Two types of incorporated sulfur were found: belonging to the sulfate anions SO_4"2"− of the electrolyte and belonging to the C-SO_3"− side groups of the indigo carmine. Raman spectroscopy confirmed the incorporation and showed that the inorganic–organic hybrid material inherited optical properties from the indigo carmine. Typical modes from pyrrolidone rings, unique for indigo carmine in the investigated system (650 and 1585 cm"−"1), were found to be the strongest for the greatest anodizing voltages used. Despite the indigo carmine incorporation, the morphology of the oxide is still nanoporous and its geometry is still tuned by the voltage applied during aluminum anodization. This work presents an inexpensive and facile approach to doping an inorganic oxide material with organic compounds. - Highlights: • Nanoporous anodic alumina was formed in electrolyte with indigo carmine. • XPS confirmed the presence of N and S in anodic alumina. • Raman spectroscopy revealed indigo carmine bands in anodic alumina. • The higher the voltage, the more indigo carmine was incorporated.

Sequence analysis of the canine mitochondrial DNA control region from shed hair samples in criminal investigations.

Science.gov (United States)

Berger, C; Berger, B; Parson, W

2012-01-01

In recent years, evidence from domestic dogs has increasingly been analyzed by forensic DNA testing. Especially, canine hairs have proved most suitable and practical due to the high rate of hair transfer occurring between dogs and humans. Starting with the description of a contamination-free sample handling procedure, we give a detailed workflow for sequencing hypervariable segments (HVS) of the mtDNA control region from canine evidence. After the hair material is lysed and the DNA extracted by Phenol/Chloroform, the amplification and sequencing strategy comprises the HVS I and II of the canine control region and is optimized for DNA of medium-to-low quality and quantity. The sequencing procedure is based on the Sanger Big-dye deoxy-terminator method and the separation of the sequencing reaction products is performed on a conventional multicolor fluorescence detection capillary electrophoresis platform. Finally, software-aided base calling and sequence interpretation are addressed exemplarily.

Parameters affecting the photocatalytic degradation of dyes using TiO2: a review

Science.gov (United States)

Reza, Khan Mamun; Kurny, ASW; Gulshan, Fahmida

2017-07-01

Traditional chemical, physical and biological processes for treating wastewater containing textile dye have such disadvantages as high cost, high energy requirement and generation of secondary pollution during treatment process. The advanced oxidation processes technology has been attracting growing attention for the decomposition of organic dyes. Such processes are based on the light-enhanced generation of highly reactive hydroxyl radicals, which oxidize the organic matter in solution and convert it completely into water, CO2 and inorganic compounds. In this presentation, the photocatalytic degradation of dyes in aqueous solution using TiO2 as photocatalyst under solar and UV irradiation has been reviewed. It is observed that the degradation of dyes depends on several parameters such as pH, catalyst concentration, substrate concentration and the presence of oxidants. Reaction temperature and the intensity of light also affect the degradation of dyes. Particle size, BET-surface area and different mineral forms of TiO2 also have influence on the degradation rate.

Efficient dye-sensitized solar cells from mesoporous zinc oxide nanostructures sensitized by N719 dye

Science.gov (United States)

Kumara, G. R. A.; Deshapriya, U.; Ranasinghe, C. S. K.; Jayaweera, E. N.; Rajapakse, R. M. G.

2018-03-01

Dye-sensitized solar cells (DSCs) have attracted a great deal of attention due to their low-cost and high power conversion efficiencies. They usually utilize an interconnected nanoparticle layer of TiO2 as the electron transport medium. From the fundamental point of view, faster mobility of electrons in ZnO is expected to contribute to better performance in DSCs than TiO2, though the actual practical situation is quite the opposite. In this research, we addressed this problem by first applying a dense layer of ZnO on FTO followed by a mesoporous layer of interconnected ZnO nanoparticle layer, both were prepared by spray pyrolysis technique. The best cell shows a power conversion efficiency of 5.2% when the mesoporous layer thickness is 14 μm and the concentration of the N719 dye in dye coating solution is 0.3 mM, while a cell without a dense layer shows 4.2% under identical conditions. The surface concentration of dye adsorbed in the cell with a dense layer and that without a dense layer are 5.00 × 10‑7 and 3.34 × 10‑7 mol/cm2, respectively. The cell with the dense layer has an electron lifetime of 54.81 ms whereas that without the dense layer is 11.08 ms. As such, the presence of the dense layer improves DSC characteristics of ZnO-based DSCs.

Decolorization of direct poly azo dye with nanophotocatalytic UV/NiO process

Directory of Open Access Journals (Sweden)

Ali Assadi

2012-01-01

Full Text Available Aims: The aim of the present study is to investigate the efficiency of ultraviolet/ nickel oxide (UV/NiO system as one form of advanced oxidation processes (AOP for decolorization of red poly azo. Materials and Methods: This study was conducted as a laboratory scale in a batch mode. Ultraviolet radiation was provided by a low pressure (11 W UV lamp. Effects of various factors including pH, different irradiation durations, different concentration of nickel oxide, and initial dye concentration were evaluated. Results: The results of the UV/NiO system′s assessment showed that UV light alone cannot remove DR 80 dye. Nickel oxide is an effective catalyst in the decolorization of dye with the nanophotocatalytic process. The decolorization efficiency increases with decreasing pH value and the optimum pH value is 4. Fainally, the highest removal efficiency achieved by UV/NiO process for DR 80 dye with concentrations of 25 mg/l and 50 mg/l was 94.3% and 82.2%, respectively. UV/NiO-based decolorization process follows pseudo-second-order reaction kinetics. Conclusions: From the findings of the present study, it can be concluded that UV/NiO process is an effective technique for decolorization of poly azo dye, DR 80, in aqueous solutions.

Gradient-dependent release of the model drug TRITC-dextran from FITC-labeled BSA hydrogel nanocarriers in the hair follicles of porcine ear skin.

Science.gov (United States)

Tran, Ngo Bich Nga Nathalie; Knorr, Fanny; Mak, Wing Cheung; Cheung, Kwan Yee; Richter, Heike; Meinke, Martina; Lademann, Jürgen; Patzelt, Alexa

2017-07-01

Hair follicle research is currently focused on the development of drug-loaded nanocarriers for the targeting of follicular structures in the treatment of skin and hair follicle-related disorders. In the present study, a dual-label nanocarrier system was implemented in which FITC-labeled BSA hydrogel nanocarriers loaded with the model drug and dye TRITC-dextran were applied topically to porcine ear skin. Follicular penetration and the distribution of both dyes corresponding to the nanocarriers and the model drug in the follicular ducts subsequent to administration to the skin were investigated using confocal laser scanning microscopy. The release of TRITC-dextran from the particles was induced by washing of the nanocarriers, which were kept in a buffer containing TRITC-labeled dextran to balance out the diffusion of the dextran during storage, thereby changing the concentration gradient. The results showed a slightly but statistically significantly deeper follicular penetration of fluorescent signals corresponding to TRITC-dextran as opposed to fluorescence corresponding to the FITC-labeled particles. The different localizations of the dyes in the cross-sections of the skin samples evidenced the release of the model drug from the labeled nanoparticles. Copyright © 2016 Elsevier B.V. All rights reserved.

Growth of TiO2-ZrO2 Binary Oxide Electrode for Dye Sensitized Solar Cell Application

International Nuclear Information System (INIS)

Than Than Win; Aye Myint Myat Kywe; Shwe Yee Win; Honey Thaw; Yin Maung Maung; Ko Ko Kyaw Soe

2011-12-01

TiO2-ZrO2 fine binary oxide was prepared by mechanochemical milling process to be homogeneous binary oxide powder. TiO2-ZrO2 paste was deposited on microscopic glass slide by rolling. It was immersed in the henna solution and annealed at 100C for 2h. It was deposited onto another glass slide and used as counter electrode (second electrode). Two glass slides were offset and two binder clips were used to hold the electrodes together. Photovoltaic properties of TiO2-ZrO2 cell were measured and it was expected to utilize the dye sensitized solar cells application.

Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor.

Science.gov (United States)

Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

2012-11-15

Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8±1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 gm(-3) d(-1)) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 gm(-3) d(-1) (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China. Copyright © 2012 Elsevier B.V. All rights reserved.

Dye-sensitized solar cell using natural dyes extracted from spinach and ipomoea

Energy Technology Data Exchange (ETDEWEB)

Chang, H., E-mail: f10381@ntut.edu.t [Department of Mechanical Engineering, National Taipei University of Technology, No. 1. Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China); Wu, H.M. [Department of Materials Engineering, Tatung University, No. 40, Sec. 3, Jhongshan N. Rd. Jhongshan District, Taipei City 104, Taiwan (China); Chen, T.L. [Department of Industrial Design, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China); Huang, K.D. [Department of Vehicle Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China); Jwo, C.S. [Department of Energy and Air-Conditioning Refrigeration Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China); Lo, Y.J. [Department of Mechanical Engineering, National Taipei University of Technology, No. 1. Sec. 3, Chung-Hsiao E. Rd., Taipei 10608, Taiwan (China)

2010-04-16

This study used spinach extract, ipomoea leaf extract and their mixed extracts as the natural dyes for a dye-sensitized solar cell (DSSC). Spinach and ipomoea leaves were first placed separately in ethanol and the chlorophyll of these two kinds of plants was extracted to serve as the natural dyes for using in DSSCs. In addition, the self-developed nanofluid synthesis system prepared a TiO{sub 2} nanofluid with an average particle size of 50 nm. Electrophoresis deposition was performed to let the TiO{sub 2} deposit nanoparticles on the indium tin oxide (ITO) conductive glass, forming a TiO{sub 2} thin film with the thickness of 11.61 {mu}m. This TiO{sub 2} thin film underwent sintering at 450 {sup o}C to enhance the compactness of thin film. Finally, the sintered TiO{sub 2} thin film was immersed in the natural dye solutions extracted from spinach and ipomoea leaves, completing the production of the anode of DSSC. This study then further inspected the fill factor, photoelectric conversion efficiency and incident photon current efficiency of the encapsulated DSSC. According to the experimental results of current-voltage curve, the photoelectric conversion efficiency of the DSSCs prepared by natural dyes from ipomoea leaf extract is 0.318% under extraction temperature of 50 {sup o}C and pH value of extraction fluid at 1.0. This paper also investigated the influence of the temperature in the extraction process of this kind of natural dye and the influence of pH value of the dye solution on the UV-VIS patterns absorption spectra of the prepared natural dye solutions, and the influence of these two factors on the photoelectric conversion efficiency of DSSC.

Enhanced photocatalytic activity of nanocellulose supported zinc oxide composite for RhB dye as well as ciprofloxacin drug under sunlight/visible light

Science.gov (United States)

Tavker, Neha; Sharma, Manu

2018-05-01

Zinc oxide nanoparticles were synthesised from zinc acetate di-hydrate via co-precipitation method. Nanocellulose was isolated from agrowaste using chemo-mechanical treatments and characterized. Nanocellulose supported zinc oxide composites were prepared through in-situ method by adding different amounts of nanocellulose. The photocatalytic efficiency of pure Zno and nanocellulose supported ZnO was calculated using RhB dye under visible light and sun light. The composites which had nanocellulose in greater ratio showed higher degradation efficiency in sunlight rather than visible light for both; dye and drug. All the composites showed high rate of photodegradation compared to bare ZnO and bare nanocellulose. The enhancement in photocatalytic activity was observed maximum where the amount of cellulose was maximum. The maximum observed rate was 0.025 min-1 using Ciprofloxacin drug due to the increase in lifetime of Z4 sample delaying the electron and hole pair recombination. The degrading efficiency of nanocellulose supported zinc oxide (NC/ZnO) composite for RhB was found to be 35% in visible, 76% in sunlight and 75% for ciprofloxacin under sunlight.

Photocatalytic degradation of methylene blue dye by zinc oxide nanoparticles obtained from precipitation and sol-gel methods.

Science.gov (United States)

Balcha, Abebe; Yadav, Om Prakash; Dey, Tania

2016-12-01

Zinc oxide (ZnO) nanoparticles were synthesized by precipitation and sol-gel methods. The aim of this study was to understand how different synthetic methods can affect the photocatalytic activity of ZnO nanoparticles. As-synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD) and UV-Visible spectroscopic techniques. XRD patterns of ZnO powders synthesized by precipitation and sol-gel methods revealed their hexagonal wurtzite structure with crystallite sizes of 30 and 28 nm, respectively. Their photocatalytic activities were evaluated by photocatalytic degradation of methylene blue, a common water pollutant, under UV radiation. The effects of operational parameters such as photocatalyst load and initial concentration of the dye on photocatalytic degradation of methylene blue were investigated. While the degradation of dye decreased over the studied dye concentration range of 20 to 100 mg/L, an optimum photocatalyst load of 250 mg/L was needed to achieve dye degradation as high as 81 and 92.5 % for ZnO prepared by precipitation and sol-gel methods, respectively. Assuming pseudo first-order reaction kinetics, this corresponded to rate constants of 8.4 × 10 -3 and 12.4 × 10 -3  min -1 , respectively. Hence, sol-gel method is preferred over precipitation method in order to achieve higher photocatalytic activity of ZnO nanostructures. Photocatalytic activity is further augmented by better choice of capping ligand for colloidal stabilization, starch being more effective than polyethylene glycol (PEG).

Rhodanine dyes for dye-sensitized solar cells : spectroscopy, energy levels and photovoltaic performance.

Science.gov (United States)

Marinado, Tannia; Hagberg, Daniel P; Hedlund, Maria; Edvinsson, Tomas; Johansson, Erik M J; Boschloo, Gerrit; Rensmo, Håkan; Brinck, Tore; Sun, Licheng; Hagfeldt, Anders

2009-01-07

Three new sensitizers for photoelectrochemical solar cells were synthesized consisting of a triphenylamine donor, a rhodanine-3-acetic acid acceptor and a polyene connection. The conjugation length was systematically increased, which resulted in two effects: first, it led to a red-shift of the optical absorption of the dyes, resulting in an improved spectral overlap with the solar spectrum. Secondly, the oxidation potential decreased systematically. The excited state levels were, however, calculated to be nearly stationary. The experimental trends were in excellent agreement with density functional theory (DFT) computations. The photovoltaic performance of this set of dyes as sensitizers in mesoporous TiO2 solar cells was investigated using electrolytes containing the iodide/triiodide redox couple. The dye with the best absorption characteristics showed the poorest solar cell efficiency, due to losses by recombination of electrons in TiO2 with triiodide. Addition of 4-tert butylpyridine to the electrolyte led to a strongly reduced photocurrent for all dyes due to a reduced electron injection efficiency, caused by a 0.15 V negative shift of the TiO2 conduction band potential.

Degradation of Synthetic Dyes by Laccases – A Mini-Review

Directory of Open Access Journals (Sweden)

Legerská Barbora

2016-06-01

Full Text Available Laccases provide a promising future as a tool to be used in the field of biodegradation of synthetic dyes with different chemical structures. These enzymes are able to oxidize a wide range of phenolic substrates without the presence of additional co-factors. Laccases have been confirmed for their potential of synthetic dye degradation from wastewater and degradation products of these enzymatic reactions become less toxic than selected dyes. This study discusses the potential of laccase enzymes as agents for laccase-catalyzed degradation in terms of biodegradation efficiency of synthetic dyes, specifically: azo dyes, triphenylmethane, indigo and anthraquinone dyes. Review also summarizes the laccase-catalyzed degradation mechanisms of the selected synthetic dyes, as well as the degradation products and the toxicity of the dyes and their degradation products.

In-situ electrochemical doping of nanoporous anodic aluminum oxide with indigo carmine organic dye

Energy Technology Data Exchange (ETDEWEB)

Stępniowski, Wojciech J., E-mail: wojciech.stepniowski@wat.edu.pl [Department of Advanced Materials and Technology, Faculty of Advanced Technology and Chemistry, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland); Norek, Małgorzata [Department of Advanced Materials and Technology, Faculty of Advanced Technology and Chemistry, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland); Budner, Bogusław [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland); Michalska-Domańska, Marta [Department of Advanced Materials and Technology, Faculty of Advanced Technology and Chemistry, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland); Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland); Nowak-Stępniowska, Agata; Bombalska, Aneta; Kaliszewski, Miron [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland); Mostek, Anna [Department of Advanced Materials and Technology, Faculty of Advanced Technology and Chemistry, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland); Thorat, Sanjay; Salerno, Marco [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, Genova I-16163 (Italy); Giersig, Michael [Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Bojar, Zbigniew [Department of Advanced Materials and Technology, Faculty of Advanced Technology and Chemistry, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland)

2016-01-01

Nanoporous anodic aluminum oxide was formed in sulfuric acid with addition of indigo carmine. During anodizing, the organic dye was incorporated into the porous oxide walls. X-ray photoelectron spectroscopy revealed the presence of nitrogen and sulfur in the anodic aluminum oxide. Two types of incorporated sulfur were found: belonging to the sulfate anions SO{sub 4}{sup 2−} of the electrolyte and belonging to the C-SO{sub 3}{sup −} side groups of the indigo carmine. Raman spectroscopy confirmed the incorporation and showed that the inorganic–organic hybrid material inherited optical properties from the indigo carmine. Typical modes from pyrrolidone rings, unique for indigo carmine in the investigated system (650 and 1585 cm{sup −1}), were found to be the strongest for the greatest anodizing voltages used. Despite the indigo carmine incorporation, the morphology of the oxide is still nanoporous and its geometry is still tuned by the voltage applied during aluminum anodization. This work presents an inexpensive and facile approach to doping an inorganic oxide material with organic compounds. - Highlights: • Nanoporous anodic alumina was formed in electrolyte with indigo carmine. • XPS confirmed the presence of N and S in anodic alumina. • Raman spectroscopy revealed indigo carmine bands in anodic alumina. • The higher the voltage, the more indigo carmine was incorporated.

Hair loss and hair-pulling in rhesus macaques (Macaca mulatta).

Science.gov (United States)

Lutz, Corrine K; Coleman, Kristine; Worlein, Julie; Novak, Melinda A

2013-07-01

Alopecia is a common problem in rhesus macaque colonies. A possible cause of this condition is hair-pulling; however the true relationship between hair-pulling and alopecia is unknown. The purpose of this study was to examine the relationship between hair loss and hair-pulling in 1258 rhesus macaques housed in 4 primate colonies across the United States. Alopecia levels ranged from 34.3% to 86.5% (mean, 49.3%) at the primate facilities. At facilities reporting a sex-associated difference, more female macaques were reported to exhibit alopecia than were males. In contrast, more males were reported to hair-pull. Animals reported to hair-pull were significantly more likely to have some amount of alopecia, but rates of hair-pulling were substantially lower than rates of alopecia, ranging from 0.6% to 20.5% (mean, 7.7%) of the populations. These results further demonstrate that hair-pulling plays only a small role in alopecia in rhesus macaques.

Hair Loss

Science.gov (United States)

... is why some people with eating disorders like anorexia and bulimia lose their hair: The body isn't getting enough protein, vitamins, and minerals to support hair growth. Some teens who are vegetarians also lose their hair if ...

Removing Hair Safely

Science.gov (United States)

... For Consumers Home For Consumers Consumer Updates Removing Hair Safely Share Tweet Linkedin Pin it More sharing ... related to common methods of hair removal. Laser Hair Removal In this method, a laser destroys hair ...

Hair Loss (Alopecia)

Science.gov (United States)

... care Kids’ zone Video library Find a dermatologist Hair loss Overview Hereditary hair loss: Millions of men ... of hair loss can often be successfully treated. Hair loss: Overview Also called alopecia (al-o-PEE- ...

Parietal scalp is another affected area in female pattern hair loss: an analysis of hair density and hair diameter

Directory of Open Access Journals (Sweden)

Rojhirunsakool S

2017-12-01

Full Text Available Salinee Rojhirunsakool, Poonkiat Suchonwanit Department of Medicine, Division of Dermatology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: Female pattern hair loss (FPHL is a common hair disease. However, studies of the quantitative measurement of FPHL are still limited. The aim of this study was to investigate the characteristics of hair density and hair diameter in normal women and FPHL patients, and further correlate the quantitative measurement with the clinical presentation of FPHL.Patients and methods: An evaluation of 471 FPHL patients and 236 normal women was carried out according to the Ludwig classification, and analysis was performed by using a computerized handheld USB camera with computer-assisted software. Various areas of the scalp, including frontal, parietal, midscalp, and occipital, were analyzed for hair density, non-vellus hair diameter, and percentage of miniaturized hair.Results: The hair density in normal women was the highest and the lowest in the midscalp and parietal areas, respectively. The FPHL group revealed the lowest hair density in the parietal area. Significant differences in hair density, non-vellus hair diameter, and percentage of miniaturized hair between the normal and FPHL groups were observed, especially in the midscalp and parietal areas.Conclusion: The parietal area is another important affected area in FPHL in addition to the midscalp area. This finding provides novel important information of FPHL and will be useful for hair transplant surgeons choosing the optimal donor sites for hair transplantation in women. Keywords: androgenetic alopecia, alopecia, phototrichogram, miniaturization

Radiation Degradation of some Commercial Dyes in Wastewater

International Nuclear Information System (INIS)

Dessouki, A.M.; Abdel-Aal, S.E.

1999-01-01

The degradation Kinetic due to irradiation of aqueous solutions of some commercial dyes, (Reactive Blue Brilliant, Reactive Yellow and Basic Blue 9 Dye (Methylene Blue 2 B), was studied. Factors affecting radiolysis of the dye such as dye concentration, irradiation dose, dose rate and ph of the solutions were studied. The effects of different additives such as nitrogen oxygen, hydrogen peroxide and sodium hypochlorite on the degradation process were investigated. The effect of irradiation dose on the different dye solutions at various concentrations, showed that the Reactive Yellow G. was very sensitive to gamma radiation. The effect of the ph of the dye solutions proved to very according type of the dye. Synergistic treatment of the dye solutions by irradiation and conventional method showed that saturation of the dye solutions with nitrogen did not enhance the radiation degradation of the dyes, while addition of oxygen resulted in a remarkable enhancement of the degradation of the dyes. Also, the addition of sodium hypochlorite (5%) and the oxidation by hydrogen peroxide resulted in more radiation degradation, Also, adsorption of the dyes onto Ga and some ion exchangers showed that Ga has the highest adsorption capacity. Radiation degradation of the toxic dye pollutants and their removal from wastewater down to concentrations not exceeding the maximum permissible concentration (Mpc) according to international standards, proved to be better than conventional methods of purification alone

Mediator-assisted decolorization and detoxification of textile dyes/dye mixture by Cyathus bulleri laccase.

Science.gov (United States)

Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, T R

2008-12-01

Laccase from basidiomycete fungus Cyathus bulleri was evaluated for its ability to decolorize a number of reactive and acidic dyes in the presence of natural and synthetic mediators. The extent of decolorization was monitored at different mediator/dye concentrations and incubation time. Among the synthetic mediators, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) was effective at low mediator/dye ratios and resulted in 80-95% decolorization at rates that varied from 226 +/- 4 nmol min(-1) mg(-1) for Reactive Orange 1 to 1,333 +/- 15 nmol min(-1) mg(-1) for Reactive Red 198. Other synthetic mediators like 1-hydroxybenzotriazole and violuric acid showed both concentration- and time-dependent increases in percent decolorization. Natural mediators like vanillin, on the other hand, were found to be less effective on all the dyes except Reactive Orange 1. Computed rates of decolorization were about twofold lower than that with ABTS. The laccase-ABTS system also led to nearly 80% decolorization for the simulated dye mixture. No clear correlation between laccase activity on the mediator and its ability to decolorize dyes was found, but pH had a significant effect: Optimum pH for decolorization coincided with the optimum pH for mediator oxidation. The treated samples were also evaluated for toxicity in model microbial systems. The laccase-mediator system appears promising for treatment of textile wastewaters.

Rapid and efficient visible light photocatalytic dye degradation using AFe2O4 (A = Ba, Ca and Sr) complex oxides

International Nuclear Information System (INIS)

Vijayaraghavan, T.; Suriyaraj, S.P.; Selvakumar, R.; Venkateswaran, R.; Ashok, Anuradha

2016-01-01

Highlights: • Alkaline earth ferrites AFe 2 O 4 (A = Ba, Ca and Sr) were synthesized by sol–gel method. • Visible light photocatalytic activity of these ferrites were studied using congo red dye degradation. • BaFe 2 O 4 exhibited the best photocatalytic activity under visible light (xenon lamp) irradiation; CaFe 2 O 4 was the best photocatalyst under natural sun light irradiation. - Abstract: Photocatalytic activity of spinel type complex oxides has been investigated in this study. Alkaline earth ferrites AFe 2 O 4 (A = Ba, Ca, Sr) were synthesized by sol–gel method. Structural characterizations reveal that the synthesized ferrites have orthorhombic crystal structures with different space groups and cell dimensions when they have different alkaline earth metals in their A site. All the synthesized ferrites exhibited their bandgap in the range 2.14–2.19 eV. Their photocatalytic activities were studied using congo red dye under sunlight and xenon lamp radiation. The substitution of Ba, Ca and Sr at A site of these ferrites had varying impact on dye degradation process. Under xenon lamp irradiation, BaFe 2 O 4 exhibited the highest percentage of dye degradation (92% after 75 min). However, CaFe 2 O 4 showed the fastest degradation of the dye (70% within 15 min). In the absence of irradiation, SrFe 2 O 4 showed the highest dye adsorption (44% after 75 min).

Enhancing photovoltaic performance of dye-sensitized solar cell by rare-earth doped oxide of Lu2O3:(Tm3+, Yb3+)

International Nuclear Information System (INIS)

Li Qingbei; Lin Jianming; Wu Jihuai; Lan Zhang; Wang Yue; Peng Fuguo; Huang Miaoliang

2011-01-01

Highlights: → Tm 3+ /Yb 3+ codoped oxide is introduced into the TiO 2 film in dye-sensitized solar cell. → The RE improves light harvest via conversion luminescence and increases photocurrent. → The RE elevates the oxide film energy level and increases the cell photovoltage. → The cell efficiency is increased by 11.1% compared to the cell lacking of RE doping. - Abstract: In order to increase of the photocurrent, photovoltage and energy conversion efficiency of dye-sensitized solar cell (DSSC), rare-earth doped oxide of Lu 2 O 3 :(Tm 3+ , Yb 3+ ) is prepared and introduced into the TiO 2 film in the DSSC. As a luminescence medium, Lu 2 O 3 :(Tm 3+ , Yb 3+ ) improves incident light harvest via a conversion luminescence process and increases photocurrent; as a p-type dopant, the rare-earth ions elevate the energy level of the oxide film and increase the photovoltage. Under a simulated solar light irradiation of 100 mW cm -2 , the light-to-electric energy conversion efficiency of the DSSC with Lu 2 O 3 :(Tm 3+ , Yb 3+ ) doping reaches 6.63%, which is increased by 11.1% compared to the DSSC without Lu 2 O 3 :(Tm 3+ , Yb 3+ ) doping.

Hair Interactions

OpenAIRE

Cani , Marie-Paule; Bertails , Florence

2006-01-01

International audience; Processing interactions is one of the main challenges in hair animation. Indeed, in addition to the collisions with the body, an extremely large number of contacts with high friction rates are permanently taking place between individual hair strands. Simulating the latter is essential: without hair self-interactions, strands would cross each other during motion or come to rest at the same location, yielding unrealistic behavior and a visible lack of hair volume. This c...

Iron phthalocyanine supported on amidoximated PAN fiber as effective catalyst for controllable hydrogen peroxide activation in oxidizing organic dyes

International Nuclear Information System (INIS)

Han, Zhenbang; Han, Xu; Zhao, Xiaoming; Yu, Jiantao; Xu, Hang

2016-01-01

Iron(II) phthalocyanine was immobilized onto amidoximated polyacrylonitrile fiber to construct a bioinspired catalytic system for oxidizing organic dyes by H 2 O 2 activation. The amidoxime groups greatly helped to anchor Iron(II) phthalocyanine molecules onto the fiber through coordination interaction, which has been confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and UV diffuse reflectance spectroscopy analyses. Electron spin resonance studies indicate that the catalytic process of physically anchored Iron(II) phthalocyanine performed via a hydroxyl radical pathway, while the catalyst bonded Iron(II) phthalocyanine through coordination effect could selectively catalyze the H 2 O 2 decomposition to generate high-valent iron-oxo species. This may result from the amidoxime groups functioning as the axial fifth ligands to favor the heterolytic cleavage of the peroxide O−O bond. This feature also enables the catalyst to only degrade the dyes adjacent to the catalytic active centers and enhances the efficient utilization of H 2 O 2 . In addition, this catalyst could effectively catalyze the mineralization of organic dyes and can be easily recycled without any loss of activity.

Calcium carbonate electronic-insulating layers improve the charge collection efficiency of tin oxide photoelectrodes in dye-sensitized solar cells

International Nuclear Information System (INIS)

Shaikh, Shoyebmohamad F.; Mane, Rajaram S.; Hwang, Yun Jeong; Joo, Oh-Shim

2015-01-01

In dye-sensitized solar cells (DSSCs), a surface passivation layer has been employed on the tin oxide (SnO 2 ) photoanodes to enhance the charge collection efficiency, and thus the power conversion efficiency. Herein, we demonstrate that the electronic-insulating layering of calcium carbonate (CaCO 3 ) can improve the charge collection efficiency in dye-sensitized solar cells designed with photoanodes. In order to evaluate the effectiveness of CaCO 3 layering, both layered and pristine SnO 2 photoanodes are characterized with regard to their structures, morphologies, and photo-electrochemical measurements. The SnO 2 -6L CaCO 3 photoanode has demonstrated as high as 3.5% power conversion efficiency; 3.5-fold greater than that of the pristine SnO 2 photoanode. The enhancement in the power conversion efficiency is corroborated with the number of the dye molecules, the passivation of surface states, a negative shift in the conduction band position, and the reduced electron recombination rate of photoelectrons following the coating of the CaCO 3 surface layer

Dual functional reduced graphene oxide as photoanode and counter electrode in dye-sensitized solar cells and its exceptional efficiency enhancement

Science.gov (United States)

Jumeri, F. A.; Lim, H. N.; Zainal, Z.; Huang, N. M.; Pandikumar, A.; Lim, S. P.

2015-10-01

The dual functionalities of reduced graphene oxide (rGO) as photoanode and counter electrode in dye-sensitized solar cells (DSSCs) is explored. A titanium dioxide (TiO2) film is deposited on an indium tin oxide (ITO) glass using an in-house aerosol-assisted chemical vapor deposition method. Graphene oxide (GO) is then introduced onto the TiO2-ITO substrate, and the GO layer is successively thermally treated to rGO. The TiO2-rGO film is used as a compact layer for the photoanode of the DSSC. A layer of zinc oxide-silver (ZnO-Ag) is introduced on top of the compact layer as an active material. Its highly porous flower-shaped morphology is advantageous for the adsorption of dye. The in-situ electrochemical polymerization method used for the fabrication of polypyrrole incorporated with rGO and p-toluenesulfonate (pTS) (Ppy-rGO-pTS) on an ITO glass is used as a counter electrode for the DSSC. The DSSC assembled with the Ppy-rGO-1.0pTS counter electrode exhibites an enhanced conversion efficiency of 1.99% under solar illumination, which is better than that using conventional Pt as a counter electrode (0.08%). This is attributed to the increased contact area between the Ppy-rGO-pTS counter electrode and electrolyte, which subsequently improves the conductivity and high electrocatalytic activities of the Ppy-rGO-pTS counter electrode.

A precise automatic system for the hair assessment in hair-care diagnosis applications.

Science.gov (United States)

Shih, H

2015-11-01

One emerging subject in medical image processing is to quantitatively assess the health and the properties of cranial hairs, including density, diameter, length, level of oiliness, and others. This information helps hair specialists with making a more accurate diagnosis and the therapy required. We develop a practical hair counting algorithm. This analytic system calculates the number of hairs on a scalp using a digital microscope camera, providing accurate information for both the hair specialist and the patient. Our proposed hair counting algorithm is substantially more accurate than the Hough-based one, and is robust to curls, oily scalp, noise-corruption, and overlapping hairs, under various levels of illumination. Rather than manually counting the hairs on a person's scalp, the proposed system determines the density, diameter, length, and level of oiliness of the hairs. We propose an automated system for counting the amount of hairs in the microscopy images. To reduce the effect of bright spots, we develop a robust morphological algorithm for color to smooth out the color and preserve the fidelity of the hair. Then, we utilize a modified Hough transform algorithm to detect the different hair lengths and to reduce any false detection due to noise. Our proposed system enables us to look at curved hairs as multiple pieces of straight lines. To avoid missing hairs when the thinning process is applied, we use edge information to discover any hidden or overlapping hairs. Finally, we employ a mutually associative regression method to label a group of line segments into a meaningful 'hair'. We demonstrated a novel approach for accurately computing the number of hairs, and successfully solved the three main obstacles in automated hair counting, including (i) oily and moist hairs, (ii) wavy and curly hairs, and (iii) under-estimation of the number of hairs occurs when hairs cross and occlude each other. The framework of this paper can be seen as the first step toward

Adsorption mechanism and kinetics of azo dye chemicals on oxide nanotubes: a case study using porous CeO_2 nanotubes

International Nuclear Information System (INIS)

Wu, Junshu; Wang, Jinshu; Du, Yucheng; Li, Hongyi; Jia, Xinjian

2016-01-01

Metal oxide nanotubes are believed to be promising materials with adsorption functionality for water purification due to their synergistic effect of the overall microscale morphology for easy separation and nanoscale surface characters providing enough surface active absorption sites. This work shows the synthesis of uniform hierarchical porous CeO_2 nanotubes via nanowire-directed templating method and describes the adsorption behavior of CeO_2 nanotubes for a typical azo dye Congo red which has resistance to oxidation and decoloration in natural conditions. Fourier transform infrared spectroscopy spectra provided the evidence that Congo red was successfully coated on the surface of CeO_2 nanotubes by both bidentate-type bridge link of Ce"4"+ cations from sulfonate SO_3"− groups and the electrostatic attraction between the protonated surface generated by oxygen vacancies and dissociated sulfonate groups. The adsorption kinetic data fitted well to the pseudo-second-order kinetic equation, whereas the Langmuir isotherm equation exhibited better correlation with the experimental data. The calculated maximum adsorption capacity from the isothermal model was 362.32 mg/g. In addition, the prepared CeO_2 nanotubes exhibited good recyclability and reusability as highly efficient adsorbents for Congo red removal after regeneration. These favorable performances enable the obtained CeO_2 nanotubes to be promising materials for dye removal from aqueous solution.Graphical AbstractCeO_2 nanotubes composed of crystallized nanoparticles exhibit well adsorption ability for a typical azo dye Congo red.

Probing photoinduced electron-transfer in graphene-dye hybrid materials for DSSC

NARCIS (Netherlands)

Guarracino, Paola; Gatti, Teresa; Canever, Nicolo; Abdu-Aguye, Mustapha; Loi, Maria Antonietta; Menna, Enzo; Franco, Lorenzo

2017-01-01

We investigated the photophysical properties of a newly synthesized hybrid material composed of a triphenylamine dye covalently bound to reduced graphene oxide, potentially relevant as a stable photosensitizer in dye-sensitized solar cells. The photophysical characterization has been carried out by

Photocatalytic degradation of reactive black-5 dye using TiO2 ...

Indian Academy of Sciences (India)

sons, considerable attention has been focused on complete oxidation of organic ... Figure 1. Molecular structure of the RB-5 dye (Reactive black 5 (RB 5) dye: molec- ular weight: 991·8 .... by collision with ground state molecules. The optimum ...

An enhanced mangiferaindica for dye sensitized solar cell application

Energy Technology Data Exchange (ETDEWEB)

Uno, U. E., E-mail: moses.emetere@covenantuniversity.edu.ng [Department of Physics, Federal University of Technology, Minna (Nigeria); Emetere, M. E., E-mail: uno-essang@yahoo.co.uk [Department of Physics, Covenant University, Ota (Nigeria); Fadipe, L. A. [Department of Chemistry, Federal University of Technology, Minna (Nigeria); Oluranti, Jonathan, E-mail: jonathan.oluranti@covenantuniversity.edu.ng [Department of Computer & Information Sciences, Covenant University, Ota (Nigeria)

2016-02-01

Titanium dioxide (T1O2) is preferred to Zinc oxide as mesoporous oxide layer because it raised the efficiency of DSSCs from 1% to 7%. The chemistry of the process however seem rigorous to allow the light induced electron injection from the adsorbed dye into the nanocrystallites i.e. which renders the TiO{sub 2} conductive. The DSSC fabricated consist of 2.25 cm{sup 2} active area of titanium dioxide coated on FTO glass (fluorine tin oxide) immersed in ethanol solution of natural dye extracted as an anode (electrode) and counter electrode. These two electrodes were coupled together and the space between them was filled with the Iodolyte AN-50 as solid electrolyte or redox mediator. The photo electrochemical parameters of the dye extracted (Mango fruit Peel) from the results obtained are short circuit current (Isc)= 1.22×10{sup −2}, current density (Jsc)=4.07×10{sup −2}, open circuit voltage (voc) =0.53V, fill factor (FF) of 0.16 and the overall conversion efficiency (Eff) =0.345%.

Microwave assisted facile hydrothermal synthesis and characterization of zinc oxide flower grown on graphene oxide sheets for enhanced photodegradation of dyes

International Nuclear Information System (INIS)

Kashinath, L.; Namratha, K.; Byrappa, K.

2015-01-01

Graphical abstract: - Highlights: • Synthesis of hybrid ZnO–GO nanocomposite via microwave assisted facile hydrothermal method. • The in situ flower like ZnO nano particles are densely decorated and anchored on the surfaces of graphene oxide sheets. • They exhibited high adsorption measurement, increase in surface area and meso/micro porous in nature. • The structure and morphology plays a vital role in enhancing the photo response activities of degradation of dyes. - Abstract: Microwave assisted hydrothermal process of synthesis of ZnO–GO nanocomposite by using ZnCl 2 and NaOH as precursors is being reported first time. In this investigation, a novel route to study on synthesis, interaction, kinetics and mechanism of hybrid zinc oxide–graphene oxide (ZnO–GO) nanocomposite using microwave assisted facile hydrothermal method has been reported. The results shows that the ZnO–GO nanocomposite exhibits an enhancement and acts as stable photo-response degradation performance of Brilliant Yellow under the UV light radiation better than pure GO and ZnO nanoparticles. The microwave exposure played a vital role in the synthesis process, it facilitates with well define crystalline structure, porosity and fine morphology of ZnO/GO nanocomposite. Different molar concentrations of ZnO precursors doped to GO sheets were been synthesized, characterized and their photodegradation performances were investigated. The optical studies by UV–vis and Photo Luminescence shows an increase in band gap of nanocomposite, which added an advantage in photodegradation performance. The in situ flower like ZnO nano particles are were densely decorated and anchored on the surfaces of graphene oxide sheets which aids in the enhancement of the surface area, adsorption, mass transfer of dyes and evolution of oxygen species. The nanocomposite having high surface area and micro/mesoporous in nature. This structure and morphology supports significantly in increasing photo catalytic

Sandwich morphology and superior dye-removal performances for nanofiltration membranes self-assemblied via graphene oxide and carbon nanotubes

Science.gov (United States)

Kang, Hui; Shi, Jie; Liu, Liyan; Shan, Mingjing; Xu, Zhiwei; Li, Nan; Li, Jing; Lv, Hanming; Qian, Xiaoming; Zhao, Lihuan

2018-01-01

To tune interlayer spacing, regulate water channel and improve stability of composite membrane, graphene oxide (GO) and oxidized carbon nanotubes (OCNTs) were assembled alternately to form sandwich morphology on a polyacrylonitrile substrate by layer-by-layer self-assembly technique. Polyelectrolyte played a part in cross-linking between GO and OCNTs. The effects about concentration ratio of GO and OCNTs on nanofiltration performance were investigated in detail. The composite membrane was used for dye rejection. When composite membrane with concentration ratio of GO and OCNTs was 10:1, water flux and rejection rate for methyl blue reached 21.71 L/(m2 h) and 99.3%, respectively. Meanwhile, this composite membrane had higher flux compared with reported literatures in which rejection also reached up to 99%. When concentration ratio of composite membranes about GO and OCNTs were 10:1 and 15:1, dye rejection for methyl blue remained 99.3% and 99.6% respectively after operating time of 50 h. Irreversible fouling ratio of composite membrane in a concentration ratio of 10:1 was only 4.4%, indicating that composite membrane had excellent antifouling performance for Bovine Serum Albumin. It was speculated that proper distribution of OCNTs in the sandwich morphology formed proper support points and water channels which benefited for a more stable performance.

Introduction of a methoxymethyl side chain into p-phenylenediamine attenuates its sensitizing potency and reduces the risk of allergy induction

Energy Technology Data Exchange (ETDEWEB)

Goebel, Carsten, E-mail: goebel.c.1@pg.com [The Procter and Gamble Co., Central Product Safety and Communications, Darmstadt (Germany); Troutman, John [The Procter and Gamble Co., Central Product Safety, Cincinnati, OH (United States); Hennen, Jenny [Dept. of Environmental Toxicology, Trier University, Trier (Germany); Rothe, Helga; Schlatter, Harald [The Procter and Gamble Co., Central Product Safety and Communications, Darmstadt (Germany); Gerberick, G. Frank [The Procter and Gamble Co., Central Product Safety, Cincinnati, OH (United States); Blömeke, Brunhilde [Dept. of Environmental Toxicology, Trier University, Trier (Germany)

2014-02-01

The strong sensitizing potencies of the most important primary intermediates of oxidative hair dyes, p-phenylenediamine (PPD) and p-toluylenediamine (PTD, i.e. 2-methyl-PPD) are well established. They are considered as the key sensitizers in hair dye allergic contact dermatitis. While modification of their molecular structure is expected to alter their sensitizing properties, it may also impair their color performance. With introduction of a methoxymethyl side chain we found the primary intermediate 2-methoxymethyl-p-phenylenediamine (ME-PPD) with excellent hair coloring performance but significantly reduced sensitizing properties compared to PPD and PTD: In vitro, ME-PPD showed an attenuated innate immune response when analyzed for its protein reactivity and dendritic cell activation potential. In vivo, the effective concentration of ME-PPD necessary to induce an immune response 3-fold above vehicle control (EC3 value) in the local lymph node assay (LLNA) was 4.3%, indicating a moderate skin sensitizing potency compared to values of 0.1 and 0.17% for PPD and PTD, respectively. Finally, assessing the skin sensitizing potency of ME-PPD under consumer hair dye usage conditions through a quantitative risk assessment (QRA) indicated an allergy induction risk negligible compared to PPD or PTD. - Highlights: • Methoxymethyl side chain in p-phenylenediamine reduces its strong skin sensitizing properties. • Reduced protein reactivity and dendritic cell activation. • Reduced skin sensitizing potency in local lymph node assay (LLNA). • Negligible allergy induction risk under hair dye usage conditions.

Introduction of a methoxymethyl side chain into p-phenylenediamine attenuates its sensitizing potency and reduces the risk of allergy induction

International Nuclear Information System (INIS)

Goebel, Carsten; Troutman, John; Hennen, Jenny; Rothe, Helga; Schlatter, Harald; Gerberick, G. Frank; Blömeke, Brunhilde

2014-01-01

The strong sensitizing potencies of the most important primary intermediates of oxidative hair dyes, p-phenylenediamine (PPD) and p-toluylenediamine (PTD, i.e. 2-methyl-PPD) are well established. They are considered as the key sensitizers in hair dye allergic contact dermatitis. While modification of their molecular structure is expected to alter their sensitizing properties, it may also impair their color performance. With introduction of a methoxymethyl side chain we found the primary intermediate 2-methoxymethyl-p-phenylenediamine (ME-PPD) with excellent hair coloring performance but significantly reduced sensitizing properties compared to PPD and PTD: In vitro, ME-PPD showed an attenuated innate immune response when analyzed for its protein reactivity and dendritic cell activation potential. In vivo, the effective concentration of ME-PPD necessary to induce an immune response 3-fold above vehicle control (EC3 value) in the local lymph node assay (LLNA) was 4.3%, indicating a moderate skin sensitizing potency compared to values of 0.1 and 0.17% for PPD and PTD, respectively. Finally, assessing the skin sensitizing potency of ME-PPD under consumer hair dye usage conditions through a quantitative risk assessment (QRA) indicated an allergy induction risk negligible compared to PPD or PTD. - Highlights: • Methoxymethyl side chain in p-phenylenediamine reduces its strong skin sensitizing properties. • Reduced protein reactivity and dendritic cell activation. • Reduced skin sensitizing potency in local lymph node assay (LLNA). • Negligible allergy induction risk under hair dye usage conditions

Hair Loss Myths.

Science.gov (United States)

DiMarco, Gabriella; McMichael, Amy

2017-07-01

INTRODUCTION: Hair loss is a common complaint seen in dermatology clinics. From frustration and attempts at self-help, patients with hair loss may present to the dermatologist with false beliefs, or myths, about the causes of their condition and what treatments are effective. METHODS: We identified 12 common myths about hair loss, categorized as myths about minoxidil treatment, vitamin and mineral supplements, natural topical treatments, and hair care practices. We performed a PubMed search to find evidence to support or refute each myth. RESULTS: We found that there is little evidence to support many of these common hair loss myths. In some cases, randomized controlled trials have investigated the effects of particular therapies and point to the effectiveness of certain hair loss treatments. DISCUSSION: In many cases, there have not been sufficient randomized controlled trials to evaluate the effect of different therapies and hair care practices on hair loss. It is best to guide patients toward treatments with a long track record of efficacy and away from those where little is known scientifically. J Drugs Dermatol. 2017;16(7):690-694..

Ethnic hair care products may increase false positives in hair drug testing.

Science.gov (United States)

Kidwell, David A; Smith, Frederick P; Shepherd, Arica R

2015-12-01

The question of why different races appear more susceptible to hair contamination by external drugs remains controversial. This research studied susceptibility of head hair to external cocaine and methamphetamine when hair products have been applied. Three different chemical classes of ethnic hair products were applied to Caucasian, Asian, and African hair. Some products increased the methamphetamine and cocaine concentrations in all hair types. A unique finding of this research is that certain ethnic hair products can replace moisture as a diffusion medium, thereby increasing the susceptibility to contamination over 100-fold compared to petroleum-based products. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Hair loss in women: medical and cosmetic approaches to increase scalp hair fullness.

Science.gov (United States)

Sinclair, R; Patel, M; Dawson, T L; Yazdabadi, A; Yip, L; Perez, A; Rufaut, N W

2011-12-01

Androgenetic alopecia affects both men and women. In men it produces male pattern hair loss with bitemporal recession and vertex baldness. In women it produces female pattern hair loss (FPHL) with diffuse alopecia over the mid-frontal scalp. FPHL occurs as a result of nonuniform hair follicle miniaturization within follicular units. Diffuse alopecia is produced by a reduction in the number of terminal fibres per follicular unit. Baldness occurs only when all hairs within the follicular units are miniaturized and is a relatively late event in women. The concepts of follicular units and primary and secondary hair follicles within follicular units are well established in comparative mammalian studies, particularly in sheep. However, discovery of these structures in the human scalp hair and investigation of the changes in follicular unit anatomy during the development of androgenetic alopecia have provided a clearer understanding of the early stages of androgenetic alopecia and how the male and female patterns of hair loss are related. FPHL is the most common cause of alopecia in women and approximately one-third of adult caucasian women experience hair loss. The impact of FPHL is predominantly psychological. While men anticipate age-related hair loss, hair loss in women is usually unexpected and unwelcome at any age. Treatment options to arrest hair loss progression and stimulate partial hair regrowth for FPHL include the androgen receptor antagonists spironolactone and cyproterone acetate, the 5α-reductase inhibitor finasteride and the androgen-independent hair growth stimulator minoxidil. These treatments appear to work best when initiated early. Hair transplantation should be considered in advanced FPHL that is resistant to medical treatments. Hair transplantation requires well-preserved hair growth over the occipital donor area. The psychological impact of FPHL may also be reduced by cosmetic products that improve the appearance of the hair. These agents work to

[Hormones and hair growth].

Science.gov (United States)

Trüeb, R M

2010-06-01

With respect to the relationship between hormones and hair growth, the role of androgens for androgenetic alopecia (AGA) and hirsutism is best acknowledged. Accordingly, therapeutic strategies that intervene in androgen metabolism have been successfully developed for treatment of these conditions. Clinical observations of hair conditions involving hormones beyond the androgen horizon have determined their role in regulation of hair growth: estrogens, prolactin, thyroid hormone, cortisone, growth hormone (GH), and melatonin. Primary GH resistance is characterized by thin hair, while acromegaly may cause hypertrichosis. Hyperprolactinemia may cause hair loss and hirsutism. Partial synchronization of the hair cycle in anagen during late pregnancy points to an estrogen effect, while aromatase inhibitors cause hair loss. Hair loss in a causal relationship to thyroid disorders is well documented. In contrast to AGA, senescent alopecia affects the hair in a diffuse manner. The question arises, whether the hypothesis that a causal relationship exists between the age-related reduction of circulating hormones and organ function also applies to hair and the aging of hair.

Complete removal of AHPS synthetic dye from water using new electro-fenton oxidation catalyzed by natural pyrite as heterogeneous catalyst.

Science.gov (United States)

Labiadh, Lazhar; Oturan, Mehmet A; Panizza, Marco; Hamadi, Nawfel Ben; Ammar, Salah

2015-10-30

The mineralization of a new azo dye - the (4-amino-3-hydroxy-2-p-tolylazo-naphthalene-1-sulfonic acid) (AHPS) - has been studied by a novel electrochemical advanced oxidation process (EAOP), consisting in electro-Fenton (EF) oxidation, catalyzed by pyrite as the heterogeneous catalyst - the so-called 'pyrite-EF'. This solid pyrite used as heterogeneous catalyst instead of a soluble iron salt, is the catalyst the system needs for production of hydroxyl radicals. Experiments were performed in an undivided cell equipped with a BDD anode and a commercial carbon felt cathode to electrogenerate in situ H2O2 and regenerate ferrous ions as catalyst. The effects on operating parameters, such as applied current, pyrite concentration and initial dye content, were investigated. AHPS decay and mineralization efficiencies were monitored by HPLC analyses and TOC measurements, respectively. Experimental results showed that AHPS was quickly oxidized by hydroxyl radicals (OH) produced simultaneously both on BDD surface by water discharge and in solution bulk from electrochemically assisted Fenton's reaction with a pseudo-first-order reaction. AHPS solutions with 175 mg L(-1) (100 mg L(-1) initial TOC) content were then almost completely mineralized in 8h. Moreover, the results demonstrated that, under the same conditions, AHPS degradation by pyrite electro-Fenton process was more powerful than the conventional electro-Fenton process. Copyright © 2015 Elsevier B.V. All rights reserved.

pH effect on decolorization of raw textile wastewater polluted with reactive dyes by advanced oxidation with uv/h2o2

NARCIS (Netherlands)

Racyte, J.; Rimeika, M.; Bruning, H.

2009-01-01

The effectiveness of the advanced oxidation process (UV/H2O2) in decolorizing real textile wastewater polluted with commercial reactive dyes - Reactive Yellow 84 and Reactive Red 141 was investigated. All the experiments were performed in a lab-scale reactor with the original high pH of the

Hair and bare skin discrimination for laser-assisted hair removal systems.

Science.gov (United States)

Cayir, Sercan; Yetik, Imam Samil

2017-07-01

Laser-assisted hair removal devices aim to remove body hair permanently. In most cases, these devices irradiate the whole area of the skin with a homogenous power density. Thus, a significant portion of the skin, where hair is not present, is burnt unnecessarily causing health risks. Therefore, methods that can distinguish hair regions automatically would be very helpful avoiding these unnecessary applications of laser. This study proposes a new system of algorithms to detect hair regions with the help of a digital camera. Unlike previous limited number of studies, our methods are very fast allowing for real-time application. Proposed methods are based on certain features derived from histograms of hair and skin regions. We compare our algorithm with competing methods in terms of localization performance and computation time and show that a much faster real-time accurate localization of hair regions is possible with the proposed method. Our results show that the algorithm we have developed is extremely fast (around 45 milliseconds) allowing for real-time application with high accuracy hair localization ( 96.48 %).

Ultrafast photodynamics of the indoline dye D149 adsorbed to porous ZnO in dye-sensitized solar cells.

Science.gov (United States)

Rohwer, Egmont; Richter, Christoph; Heming, Nadine; Strauch, Kerstin; Litwinski, Christian; Nyokong, Tebello; Schlettwein, Derck; Schwoerer, Heinrich

2013-01-14

We investigate the ultrafast dynamics of the photoinduced electron transfer between surface-adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye-sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I(-)/I(3)(-) redox electrolyte typical for dye-sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert-butyl alcohol shows excited-state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge-transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of changes in the inorganic matrix of dye sensitized solar cells during preparation

Energy Technology Data Exchange (ETDEWEB)

Graaf, Harald; Maedler, Carsten; Kehr, Mirko; Baumgaertel, Thomas [Institute of Physics, Chemnitz University of Technology, Reichenhainer Str. 70, 09126 Chemnitz (Germany); Oekermann, Torsten [Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, 30167 Hannover (Germany)

2009-12-15

Nanoporous zinc oxide films can be prepared by electrochemical co-deposition with the dye eosin Y (EY) as template. A subsequent desorption of the dye with aqueous KOH is a key step for the increased efficiency of such dye sensitized solar cells (DSSC). In this contribution, the partial dissolving and reorganization of the zinc oxide film during the desorption step has been studied in detail by X-ray diffraction, Kelvin probe force microscopy, and atomic force microscopy (AFM) as well as scanning electron microscopy. It is found that the reorganization leads to an enhancement of crystal orientation and a reduction of the defect concentration at the surface of zinc oxide, being a possible reason for suppressed recombination of electrons in these films. Also, an increased defect concentration in ZnO was found when co-deposited with EY. For these co-deposited films, AFM investigations showed a coverage of the surface with dye aggregates. High resolution AFM investigations revealed the nanocrystalline and highly porous structure of the inorganic matrix after desorption of the dye. Photographs of the organic/inorganic hybrid thin film material were investigated in this study. Left side: film directly after deposition, right side: after desorption of the organic dye. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Radiation induced degradation of dyes-An overview

International Nuclear Information System (INIS)

Rauf, M.A.; Ashraf, S. Salman

2009-01-01

Synthetic dyes are a major part of our life. Products ranging from clothes to leather accessories to furniture all depend on extensive use of organic dyes. An unfortunate side effect of extensive use of these chemicals is that huge amounts of these potentially carcinogenic compounds enter our water supplies. Various advanced oxidation processes (AOPs) including the use of high-energy radiation have been developed to degrade these compounds. In this review, dye decoloration and degradation as a result of its exposure to high energy radiation such as gamma radiation and pulsed electron beam are discussed in detail. The role of various transient species such as ·H, ·OH and e aq - are taken into account as reported by various researchers. Literature citations in this area show that e aq - is very effective in decolorization but is less active in the further degradation of the products formed. The degradation of the dyes is initiated exclusively by ·OH attack on electron-rich sites of the dye molecules. Additionally, various parameters that affect the efficiency of radiation induced degradation of dyes, such as effect of radiation dose, oxygen, pH, hydrogen peroxide, added ions and dye classes are also reviewed and summarized. Lastly, pilot plant application of radiation for wastewater treatment is briefly discussed.

Enhanced photovoltaic performance of dye-sensitized solar cells based on nickel oxide supported on nitrogen-doped graphene nanocomposite as a photoanode.

Science.gov (United States)

Ranganathan, Palraj; Sasikumar, Ragu; Chen, Shen-Ming; Rwei, Syang-Peng; Sireesha, Pedaballi

2017-10-15

We applied the nitrogen-doped graphene@nickel oxide (NGE/NiO) nanocomposite doped TiO 2 as a photo-anode for dye-sensitized solar cells (DSSCs) on fluorine-doped tin oxide (FTO) substrates by screen printing method. Power conversion efficiency (PCE) of 9.75% was achieved for this DSSCs device, which is greater than that of DSSCs devices using GO/TiO 2 , and NiO/TiO 2 based photo-anodes (PCE=8.55, and 9.11%). Also, the fill factor (FF) of the DSSCs devices using the NGE/NiO/TiO 2 nanocomposite photo-anode was better than that of other photo-anodes. The NGE/NiO/TiO 2 short-circuit photocurrent density (J sc ) of 19.04mAcm -2 , open circuit voltage (V oc ) of 0.76V, fill factor (FF) of 0.67 and dye absorption rate 0.21×10 -6 molcm -2 . The obtained results suggest that as-prepared NGE/NiO/TiO 2 nanocomposite is suitable photo-anode for DSSCs application. Copyright © 2017 Elsevier Inc. All rights reserved.

A comparative study of quantum yield and electrical energy per order (E(Eo)) for advanced oxidative decolourisation of reactive azo dyes by UV light.

Science.gov (United States)

Muruganandham, M; Selvam, K; Swaminathan, M

2007-06-01

This paper evaluates the quantum yield and electrical energy per order (E(Eo)) efficiency of Reactive Orange 4 (RO4) and Reactive Yellow 14 (RY14) azo dyes by three advanced oxidation processes (AOPs). Both dyes were completely decolourised by all these processes. The relative decolourisation efficiencies of these processes were in the following order: Fe(2+)/H(2)O(2)/UV>UV/TiO(2)>UV/H(2)O(2). The low efficiency of UV/H(2)O(2) process is mainly due to low UV absorption by hydrogen peroxide at the 365nm. The figure of merit E(Eo) values showed that UV/H(2)O(2) process consumes more electrical energy than the other two processes. The electrical energy consumption is in the following order: UV/H(2)O(2)>UV/TiO(2)>Fe(2+)/H(2)O(2)/UV. At low initial dye concentration higher quantum yield was observed in UV/TiO(2) process, whereas in photo-Fenton process higher quantum yield was observed at high initial dye concentration. The structure of dye molecule also influences the quantum yield and E(Eo) value.

A comparative study of quantum yield and electrical energy per order (E Eo) for advanced oxidative decolourisation of reactive azo dyes by UV light

International Nuclear Information System (INIS)

Muruganandham, M.; Selvam, K.; Swaminathan, M.

2007-01-01

This paper evaluates the quantum yield and electrical energy per order (E Eo ) efficiency of Reactive Orange 4 (RO4) and Reactive Yellow 14 (RY14) azo dyes by three advanced oxidation processes (AOPs). Both dyes were completely decolourised by all these processes. The relative decolourisation efficiencies of these processes were in the following order: Fe 2+ /H 2 O 2 /UV > UV/TiO 2 > UV/H 2 O 2 . The low efficiency of UV/H 2 O 2 process is mainly due to low UV absorption by hydrogen peroxide at the 365 nm. The figure of merit E Eo values showed that UV/H 2 O 2 process consumes more electrical energy than the other two processes. The electrical energy consumption is in the following order: UV/H 2 O 2 > UV/TiO 2 > Fe 2+ /H 2 O 2 /UV. At low initial dye concentration higher quantum yield was observed in UV/TiO 2 process, whereas in photo-Fenton process higher quantum yield was observed at high initial dye concentration. The structure of dye molecule also influences the quantum yield and E Eo value

An Overview: Recent Development of Titanium Oxide Nanotubes as Photocatalyst for Dye Degradation

Directory of Open Access Journals (Sweden)

Chin Wei Lai

2014-01-01

Full Text Available Today, organic dyes are one of the largest groups of pollutants release into environment especially from textile industry. It is highly toxic and hazardous to the living organism; thus, the removal of these dyes prior to discharge into the environment is essential. Varieties of techniques have been employed to degrade organic dyes and heterogeneous photocatalysis involving titanium dioxide (TiO2 appears to be the most promising technology. In recent years, TiO2 nanotubes have attracted much attention due to their high surface area and extraordinary characteristics. This paper presents a critical review of recent achievements in the modification of TiO2 nanotubes for dye degradation. The photocatalytic activity on dye degradation can be further enhanced by doping with cationic or anionic dopant.

Effectiveness of dye sensitised solar cell under low light condition using wide band dye

Energy Technology Data Exchange (ETDEWEB)

Sahmer, Ahmad Zahrin, E-mail: ahmadzsahmer@gmail.com; Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my; Zaine, Siti Nur Azella, E-mail: ct.azella@gmail.com [Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

2015-07-22

Dye sensistised solar cell (DSC) based on nanocrystalline TiO{sub 2} has the potential to be used in indoor consumer power application. In realizing this, the DSC must be optimized to generate power under low lighting condition and under wider visible light range. The use of wide band dye N749 which has a wider spectrum sensitivity increases the photon conversion to electron between the visible light spectrums of 390nm to 700nm. This paper reports the study on the effectiveness of the dye solar cell with N749 dye under low light condition in generating usable power which can be used for indoor consumer application. The DSC was fabricated using fluorine doped tin oxide (FTO) glass with screen printing method and the deposited TiO{sub 2} film was sintered at 500°C. The TiO{sub 2} coated FTO glass was then soaked in the N749 dye, assembled into test cell, and tested under the standard test condition at irradiance of 1000 W/m{sup 2} with AM1.5 solar soaker. The use of the 43T mesh for the dual pass screen printing TiO{sub 2} paste gives a uniform TiO{sub 2} film layer of 16 µm. The low light condition was simulated using 1/3 filtered irradiance with the solar soaker. The fabricated DSC test cell with the N749 dye was found to have a higher efficiency of 6.491% under low light condition compared to the N719 dye. Under the standard test condition at 1 sun the N749 test cell efficiency is 4.55%. The increases in efficiency is attributed to the wider spectral capture of photon of the DSC with N749 dye. Furthermore, the use of N749 dye is more effective under low light condition as the V{sub OC} decrement is less significant compared to the latter.

Iron phthalocyanine supported on amidoximated PAN fiber as effective catalyst for controllable hydrogen peroxide activation in oxidizing organic dyes

Energy Technology Data Exchange (ETDEWEB)

Han, Zhenbang, E-mail: hzbang@aliyun.com [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); Key Laboratory of Advanced Textile Composite Materials, Ministry of Education of China, Tianjin 300387 (China); Han, Xu [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); Zhao, Xiaoming, E-mail: zhaoxiaoming@tjpu.edu.cn [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); Key Laboratory of Advanced Textile Composite Materials, Ministry of Education of China, Tianjin 300387 (China); Yu, Jiantao; Xu, Hang [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China)

2016-12-15

Iron(II) phthalocyanine was immobilized onto amidoximated polyacrylonitrile fiber to construct a bioinspired catalytic system for oxidizing organic dyes by H{sub 2}O{sub 2} activation. The amidoxime groups greatly helped to anchor Iron(II) phthalocyanine molecules onto the fiber through coordination interaction, which has been confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and UV diffuse reflectance spectroscopy analyses. Electron spin resonance studies indicate that the catalytic process of physically anchored Iron(II) phthalocyanine performed via a hydroxyl radical pathway, while the catalyst bonded Iron(II) phthalocyanine through coordination effect could selectively catalyze the H{sub 2}O{sub 2} decomposition to generate high-valent iron-oxo species. This may result from the amidoxime groups functioning as the axial fifth ligands to favor the heterolytic cleavage of the peroxide O−O bond. This feature also enables the catalyst to only degrade the dyes adjacent to the catalytic active centers and enhances the efficient utilization of H{sub 2}O{sub 2}. In addition, this catalyst could effectively catalyze the mineralization of organic dyes and can be easily recycled without any loss of activity.

A New Synergetic Nanocomposite for Dye Degradation in Dark and Light

Science.gov (United States)

Lakshmi Prasanna, V.; Rajagopalan, Vijayaraghavan

2016-12-01

Environmental hazard caused due to the release of dyes in effluents is a concern in many countries. Among the various methods to combat this problem, Advanced Oxidation Process, in which semiconductor photocatalysts are used, is considered the most effective one. These materials release Reactive Oxygen Species (ROS) such as hydroxyl radical and superoxide in suspension that degrade the dyes into non-toxic minerals. However, this process requires visible or UV light for activation. Hence, there is a need to develop materials that release ROS, both in the absence and in the presence of light, so that the efficiency of dye removal is enhanced. Towards this objective, we have designed and synthesized a new nanocomposite ZnO2/polypyrrole which releases ROS even in the dark. The ROS released in the dark and in light were estimated by standard methods. It is to be noted that ZnO2 degrades the dye only under UV light but not in dark or in the presence of visible light. We propose the mechanism of dye degradation in dark and light. The synergically coupled nanocomposite of ZnO2/ppy is the first example that degrades dyes in the dark, through advanced oxidation process without employing additional reagents.

Hair Pulling (Trichotillomania)

Science.gov (United States)

... for Families - Vietnamese Spanish Facts for Families Guide Hair Pulling (Trichotillomania) No. 96; Reviewed July 2013 It ... for children and adolescents to play with their hair. However, frequent or obsessive hair pulling can lead ...

Photodegradation of polymer-dispersed perylene di-imide dyes

Science.gov (United States)

Tanaka, Nobuaki; Barashkov, Nikolay; Heath, Jerry; Sisk, Wade N.

2006-06-01

Polymer-dispersed perylene di-imide dye photodegradation is investigated by monitoring the fluorescence intensity as a function of 532 nm laser pulses. Anaerobically irradiated polymer-dye films exhibited an accelerated decrease in fluorescence intensity, which was partially recovered upon exposure to oxygen. Decelerated photodegradation rates were observed for perylene di-imide ethanol solutions upon the addition of a singlet oxygen quenching antioxidant. These observations suggest reversible photoreduction and type II photo-oxidation as important photodegradation mechanisms. Type II photo-oxidation for perylene red 532 nm irradiation is supported by a singlet oxygen quantum yield of 0.09±0.03, determined via detection of time-resolved O2 (a1Δg —> X3∑g-) infrared phosphorescence.

Recent Advances in Heterogeneous Photocatalytic Decolorization of Synthetic Dyes

Science.gov (United States)

Muhd Julkapli, Nurhidayatullaili; Bagheri, Samira; Bee Abd Hamid, Sharifah

2014-01-01

During the process and operation of the dyes, the wastes produced were commonly found to contain organic and inorganic impurities leading to risks in the ecosystem and biodiversity with the resultant impact on the environment. Improper effluent disposal in aqueous ecosystems leads to reduction of sunlight penetration which in turn diminishes photosynthetic activity, resulting in acute toxic effects on the aquatic flora/fauna and dissolved oxygen concentration. Recently, photodegradation of various synthetic dyes has been studied in terms of their absorbance and the reduction of oxygen content by changes in the concentration of the dye. The advantages that make photocatalytic techniques superior to traditional methods are the ability to remove contaminates in the range of ppb, no generation of polycyclic compounds, higher speed, and lower cost. Semiconductor metal oxides, typically TiO2, ZnO, SnO, NiO, Cu2O, Fe3O4, and also CdS have been utilized as photocatalyst for their nontoxic nature, high photosensitivity, wide band gap and high stability. Various process parameters like photocatalyst dose, pH and initial dye concentrations have been varied and highlighted. Research focused on surface modification of semiconductors and mixed oxide semiconductors by doping them with noble metals (Pt, Pd, Au, and Ag) and organic matter (C, N, Cl, and F) showed enhanced dye degradation compared to corresponding native semiconductors. This paper reviews recent advances in heterogeneous photocatalytic decolorization for the removal of synthetic dyes from water and wastewater. Thus, the main core highlighted in this paper is the critical selection of semiconductors for photocatalysis based on the chemical, physical, and selective nature of the poisoning dyes. PMID:25054183

Recent Advances in Heterogeneous Photocatalytic Decolorization of Synthetic Dyes

Directory of Open Access Journals (Sweden)

Nurhidayatullaili Muhd Julkapli

2014-01-01

Full Text Available During the process and operation of the dyes, the wastes produced were commonly found to contain organic and inorganic impurities leading to risks in the ecosystem and biodiversity with the resultant impact on the environment. Improper effluent disposal in aqueous ecosystems leads to reduction of sunlight penetration which in turn diminishes photosynthetic activity, resulting in acute toxic effects on the aquatic flora/fauna and dissolved oxygen concentration. Recently, photodegradation of various synthetic dyes has been studied in terms of their absorbance and the reduction of oxygen content by changes in the concentration of the dye. The advantages that make photocatalytic techniques superior to traditional methods are the ability to remove contaminates in the range of ppb, no generation of polycyclic compounds, higher speed, and lower cost. Semiconductor metal oxides, typically TiO2, ZnO, SnO, NiO, Cu2O, Fe3O4, and also CdS have been utilized as photocatalyst for their nontoxic nature, high photosensitivity, wide band gap and high stability. Various process parameters like photocatalyst dose, pH and initial dye concentrations have been varied and highlighted. Research focused on surface modification of semiconductors and mixed oxide semiconductors by doping them with noble metals (Pt, Pd, Au, and Ag and organic matter (C, N, Cl, and F showed enhanced dye degradation compared to corresponding native semiconductors. This paper reviews recent advances in heterogeneous photocatalytic decolorization for the removal of synthetic dyes from water and wastewater. Thus, the main core highlighted in this paper is the critical selection of semiconductors for photocatalysis based on the chemical, physical, and selective nature of the poisoning dyes.

Influence of Dye Adsorbtion Time on TiO2 Dye-Sensitized Solar Cell with Krokot Extract (Portulaca Oleracea. L as A Natural Sensitizer

Directory of Open Access Journals (Sweden)

Didik Krisdiyanto

2015-03-01

Full Text Available Dye sensitized solar cells (DSSC photoelectrodes were fabricated using titanium oxide (TiO2 and sensitized with the krokot extract dye. This study investigated the effect of dye adsorption time to an efficiency of the solar cells. The fabrication cells immersed with krokot extract dye for 1, 8 and 26 hours. The photochemical performance of the DSSC showed that the open circuit voltage (Voc were 0.33, 0.036 and 0.27 V with short photocurrent density (Isc 8.00 x 10-5, 6.80 x 10-7 and 3.10 x 10-4. The photo-to-electric conversion efficiency of the DSSC reached 4.63 x 10-3 % for 26 hours adsorption time.

A Study on Scalp Hair Health and Hair Care Practices among Malaysian Medical Students.

Science.gov (United States)

Nayak, B Satheesha; Ann, Chua Yuet; Azhar, Azeldeen Bin; Ling, Emily Chan Su; Yen, Wong Hui; Aithal, P Ashwini

2017-01-01

Scalp care is essential because it determines the health and condition of the hair and prevents the diseases of scalp and hair. The objectives of our study were to correlate race and hair types, to determine the awareness of hair care among Malaysian medical students, and to distinguish the factors that affect the health of hair and scalp. It was a cross-sectional study wherein validated questionnaires were given to 240 medical undergraduate students who belonged to three ethnic races of Malaysia, i.e., Chinese, Malay, and Malaysian Indians after their informed consent. The results were then analyzed using percentage statistics. Chinese students had comparatively healthier scalp without dandruff. Most Chinese and Indians had silky type of hair while Malay had dry, rough hair. Chinese and Indians colored their hair and used various styling methods; while among the Malays, this percentage was very less. Regarding hair care practices, males used only shampoo and females used shampoo and conditioner for hair wash. Students also faced dietary and examination-related stress. Results indicate that there exist morphological differences in hair among the studied population. Since most students color their hair and employ various hairstyling methods, they should be educated regarding best hair care practices to improve their scalp hair condition and health.

Artificial sensory hairs based on the flow sensitive receptor hairs of crickets

NARCIS (Netherlands)

Dijkstra, Marcel; van Baar, J.J.J.; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; de Boer, J.H.; Krijnen, Gijsbertus J.M.

2005-01-01

This paper presents the modelling, design, fabrication and characterization of flow sensors based on the wind-receptor hairs of crickets. Cricket sensory hairs are highly sensitive to drag-forces exerted on the hair shaft. Artificial sensory hairs have been realized in SU-8 on suspended SixNy

Electrochemical degradation of reactive dyes at different DSA compositions

Energy Technology Data Exchange (ETDEWEB)

Silva, Rodrigo G. da; Aquino Neto, Sydney; Andrade, Adalgisa R. de, E-mail: ardandra@ffclrp.usp.b [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Filosofia Ciencias e Letras. Dept. de Quimica

2011-07-01

This paper investigates the electrochemical oxidation of the reactive dyes reactive blue 4 (RB-4) and reactive orange 16 (RO-16) on RuO{sub 2} dimensionally stable anode (DSA) electrodes. Electrolysis was achieved under galvanostatic control as a function of supporting electrolyte and electrode composition. The electrolyses, performed in either the presence or absence of NaCl, were able to promote efficient color removal; moreover, at low chloride concentration (0.01 mol L{sup -1}), total color removal was obtained after just 10 min of electrolysis, and a significant increase in total dye combustion was achieved for all the studied anodes in chloride medium (reaching ca. 80% - chemical oxygen demand - COD removal). No significant enhancement in dye color removal or mineralization was observed upon increasing chloride concentration. The influence of oxide composition on dye elimination seems to be significant in both media (with or without chloride), being Ti/Ru{sub 0.30}Ti{sub 0.70}O{sub 2}, the most active material for organic compound oxidation. The oxygen evolution reaction was shown to be a limiting reaction in both supporting electrolytes; i.e., NaCl and Na{sub 2}SO{sub 4}, and its competition with organic compound oxidation remained an obstacle. The adsorbable organo halogens formation study revealed that there is slight consumption of the undesirable species formed within the first minutes of the electrolysis, being Ti/(RuO{sub 2}){sub 0.70}(Ta{sub 2}O{sub 5}){sub 0.30} the most environmentally friendly composition. Both anode composition and chloride concentration affect the formation of these undesirable compounds. (author)

Hair cosmetics and camouflage technics

Directory of Open Access Journals (Sweden)

Zahide Eriş Eken

2014-06-01

Full Text Available Hair is composed of a mixture of trace elements in small quantities, proteins, lipids and water. Proteins consist of helical polypeptide amino acid molecules. In the hair cells; polypeptide chains of keratin protein would be organized in filaments. In recent years, hair cosmetics showed a significant change and development. The content of shampoos which is used to cleanse the hair has enhanced significantly. Hair conditioner, hair styling products, pomades, brilliantine, and gloss sprays, hair protective products, camouflage products are most commonly used hair cosmetics. Hair shaping procedures are frequently applied.

Metal-free indoline dye sensitized solar cells based on nanocrystalline Zn{sub 2}SnO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Huang, Lihua [Institute of New Energy Technology and Nano-Materials, Fuzhou University, Fuzhou, Fujian 350002 (China); Jiang, Lilong; Wei, Mingding [Institute of New Energy Technology and Nano-Materials, Fuzhou University, Fuzhou, Fujian 350002 (China); National Engineering Research Center for Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, Fujian 350002 (China)

2010-02-15

Zn{sub 2}SnO{sub 4} nanocrystals were synthesized and first used as the electrode materials for the metal-free indoline dyes sensitized solar cells (DSSCs). The highest efficiency of 3.08% was achieved for a D131 DSSC. This might be attributed to the fact that the D131 dye has a greater positive oxidation potential, which can lead to rapid dye regeneration, avoiding the geminate charge recombination between oxidized dye molecules and injected electrons in the Zn{sub 2}SnO{sub 4} film. The efficiency can be improved significantly using a mixture solution of D131 and N719 dyes for which an efficiency of 3.6% was obtained. (author)

Hair restoration.

Science.gov (United States)

Rawnsley, Jeffrey D

2008-08-01

The impact of male hair loss as a personal and social marker of aging is tremendous and its persistence as a human concern throughout recorded history places it in the forefront of male concern about the physical signs of aging. Restoration of the frontal hairline has the visual effect of re-establishing facial symmetry and turning back time. Follicular unit transplantation has revolutionized hair restoration, with its focus on redistributing large numbers of genetically stable hair to balding scalp in a natural distribution. Follicular unit hair restoration surgery is a powerful tool for the facial plastic surgeon in male aesthetic facial rejuvenation because it offers high-impact, natural-appearing results with minimal downtime and risk for adverse outcome.

Decolorization of brilliant green dye using immersed lamp sonophotocatalytic reactor

Science.gov (United States)

Gole, Vitthal L.; Priya, Astha; Danao, Sanjay P.

2017-12-01

The textile and dye industries require an enormous amount of water for processing and produce a large volume of wastewater. Generated wastewater had potential hazards and a threat to the aquatic biota. The present work investigates the decolorization of brilliant green dye using a combination of two advanced oxidation techniques viz sonocatalysis and photocatalysis (immersed lamp) known as sonophotocatalysis (3 L capacity). The efficiency of decolorization is further improved in the presence of various additives viz. copper oxide, zinc oxide, and sodium chloride. The maximum decolorization of brilliant green (BG) (94.8% in 120 min) obtained in the presence of zinc oxide. The total organic carbon of the treated samples was measured to monitor complete mineralization of BG. The sonophotocatalytic process (in the presence of zinc oxide) shows maximum mineralization. Synergic combination of two oxidation processes increased the production of oxidizing radicals. Continuous cleaning of catalyst surface (due to sonolysis effect) improves the activity of the catalyst for photolysis operation. The present work is highly useful for the development of a sonophotocatalytic process.

Safety assessment of personal care products/cosmetics and their ingredients

International Nuclear Information System (INIS)

Nohynek, Gerhard J.; Antignac, Eric; Re, Thomas; Toutain, Herve

2010-01-01

We attempt to review the safety assessment of personal care products (PCP) and ingredients that are representative and pose complex safety issues. PCP are generally applied to human skin and mainly produce local exposure, although skin penetration or use in the oral cavity, on the face, lips, eyes and mucosa may also produce human systemic exposure. In the EU, US and Japan, the safety of PCP is regulated under cosmetic and/or drug regulations. Oxidative hair dyes contain arylamines, the most chemically reactive ingredients of PCP. Although arylamines have an allergic potential, taking into account the high number of consumers exposed, the incidence and prevalence of hair dye allergy appears to be low and stable. A recent (2001) epidemiology study suggested an association of oxidative hair dye use and increased bladder cancer risk in consumers, although this was not confirmed by subsequent or previous epidemiologic investigations. The results of genetic toxicity, carcinogenicity and reproductive toxicity studies suggest that modern hair dyes and their ingredients pose no genotoxic, carcinogenic or reproductive risk. Recent reports suggest that arylamines contained in oxidative hair dyes are N-acetylated in human or mammalian skin resulting in systemic exposure to traces of detoxified, i.e. non-genotoxic, metabolites, whereas human hepatocytes were unable to transform hair dye arylamines to potentially carcinogenic metabolites. An expert panel of the International Agency on Research of Cancer (IARC) concluded that there is no evidence for a causal association of hair dye exposure with an elevated cancer risk in consumers. Ultraviolet filters have important benefits by protecting the consumer against adverse effects of UV radiation; these substances undergo a stringent safety evaluation under current international regulations prior to their marketing. Concerns were also raised about the safety of solid nanoparticles in PCP, mainly TiO 2 and ZnO in sunscreens. However

Safety assessment of personal care products/cosmetics and their ingredients.

Science.gov (United States)

Nohynek, Gerhard J; Antignac, Eric; Re, Thomas; Toutain, Herve

2010-03-01

We attempt to review the safety assessment of personal care products (PCP) and ingredients that are representative and pose complex safety issues. PCP are generally applied to human skin and mainly produce local exposure, although skin penetration or use in the oral cavity, on the face, lips, eyes and mucosa may also produce human systemic exposure. In the EU, US and Japan, the safety of PCP is regulated under cosmetic and/or drug regulations. Oxidative hair dyes contain arylamines, the most chemically reactive ingredients of PCP. Although arylamines have an allergic potential, taking into account the high number of consumers exposed, the incidence and prevalence of hair dye allergy appears to be low and stable. A recent (2001) epidemiology study suggested an association of oxidative hair dye use and increased bladder cancer risk in consumers, although this was not confirmed by subsequent or previous epidemiologic investigations. The results of genetic toxicity, carcinogenicity and reproductive toxicity studies suggest that modern hair dyes and their ingredients pose no genotoxic, carcinogenic or reproductive risk. Recent reports suggest that arylamines contained in oxidative hair dyes are N-acetylated in human or mammalian skin resulting in systemic exposure to traces of detoxified, i.e. non-genotoxic, metabolites, whereas human hepatocytes were unable to transform hair dye arylamines to potentially carcinogenic metabolites. An expert panel of the International Agency on Research of Cancer (IARC) concluded that there is no evidence for a causal association of hair dye exposure with an elevated cancer risk in consumers. Ultraviolet filters have important benefits by protecting the consumer against adverse effects of UV radiation; these substances undergo a stringent safety evaluation under current international regulations prior to their marketing. Concerns were also raised about the safety of solid nanoparticles in PCP, mainly TiO(2) and ZnO in sunscreens. However

Radiolysis of organic triphenylmethane, anthraquinone, xanthene, oxazine, thiazine and azo dyes in polymeric films

International Nuclear Information System (INIS)

Khabarov, V.N.; Kozlov, L.L.; Molin, A.A.; Mekhanic, T.V.

1988-01-01

Effect of air oxygen and temperature (77 - 323 K) on decolorization radiation-chemical processes of triphenylmethane, anthraquinone, xanthene, oxazine, thiazine and azo dyes in different polymeric matrices is investigated. Radiation decolorization rate for the majority of dyes increases at the irradiation in O 2 presence, which is, presumably, connected with the dye oxidation by the singlet oxygen. The organic dyes manifest the most radiation resistance in polyethyleneterephthalate and polystyrene films

Ponceau 6R dye decoloration and chromate reduction simultaneously in acid medium

Directory of Open Access Journals (Sweden)

Seddique M. Ahmed

2015-07-01

Full Text Available The degradation efficiency and kinetic degradation reaction of Ponceau 6R dye using potassium chromate have been investigated under various experimental conditions: different concentrations of H2SO4 and temperatures. The immediate change of the red coloration (λmax = 518 nm to colorless was observed after addition of inorganic oxidizing agent (K2CrO4 into the protonated form of Ponceau 6R dye after 48 h. This observation could be attributed to the highest oxidized form of this dye obtained (the quinoid one, which undergoes a hydrolysis reaction to produce p-hydroquinone (H2Q by a mechanism similar to Schiff-base hydrolysis. The cationic form of this matrix is a crucial feature for the hydrolysis process. A kinetic model for oxidation of Ponceau 6R by the combination of chromate was developed based on experimental results. The observed kinetic reaction coefficient was determined and correlated as a function of UV spectral intensity of Ponceau 6R at 518 nm. The degradation rate follows pseudo-first order kinetics with respect to dye concentration.

Viking Age Hair

Directory of Open Access Journals (Sweden)

Elisabeth Arwill-Nordbladh

2016-11-01

Full Text Available A study of hair in the Viking Age. The article draws on medieval Icelandic and Scandinavian texts for interpretation. Further information is taken from pictoral representations of viking hair styles and decoration, hairdressing artefacts, figurines and actual remains of hair.

Limits of ZnO Electrodeposition in Mesoporous Tin Doped Indium Oxide Films in View of Application in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Christian Dunkel

2014-04-01

Full Text Available Well-ordered 3D mesoporous indium tin oxide (ITO films obtained by a templated sol-gel route are discussed as conductive porous current collectors. This paper explores the use of such films modified by electrochemical deposition of zinc oxide (ZnO on the pore walls to improve the electron transport in dye-sensitized solar cells (DSSCs. Mesoporous ITO film were dip-coated with pore sizes of 20–25 nm and 40–45 nm employing novel poly(isobutylene-b-poly(ethylene oxide block copolymers as structure-directors. After electrochemical deposition of ZnO and sensitization with the indoline dye D149 the films were tested as photoanodes in DSSCs. Short ZnO deposition times led to strong back reaction of photogenerated electrons from non-covered ITO to the electrolyte. ITO films with larger pores enabled longer ZnO deposition times before pore blocking occurred, resulting in higher efficiencies, which could be further increased by using thicker ITO films consisting of five layers, but were still lower compared to nanoporous ZnO films electrodeposited on flat ITO. The major factors that currently limit the application are the still low thickness of the mesoporous ITO films, too small pore sizes and non-ideal geometries that do not allow obtaining full coverage of the ITO surface with ZnO before pore blocking occurs.

Limits of ZnO Electrodeposition in Mesoporous Tin Doped Indium Oxide Films in View of Application in Dye-Sensitized Solar Cells

Science.gov (United States)

Dunkel, Christian; von Graberg, Till; Smarsly, Bernd M.; Oekermann, Torsten; Wark, Michael

2014-01-01

Well-ordered 3D mesoporous indium tin oxide (ITO) films obtained by a templated sol-gel route are discussed as conductive porous current collectors. This paper explores the use of such films modified by electrochemical deposition of zinc oxide (ZnO) on the pore walls to improve the electron transport in dye-sensitized solar cells (DSSCs). Mesoporous ITO film were dip-coated with pore sizes of 20–25 nm and 40–45 nm employing novel poly(isobutylene)-b-poly(ethylene oxide) block copolymers as structure-directors. After electrochemical deposition of ZnO and sensitization with the indoline dye D149 the films were tested as photoanodes in DSSCs. Short ZnO deposition times led to strong back reaction of photogenerated electrons from non-covered ITO to the electrolyte. ITO films with larger pores enabled longer ZnO deposition times before pore blocking occurred, resulting in higher efficiencies, which could be further increased by using thicker ITO films consisting of five layers, but were still lower compared to nanoporous ZnO films electrodeposited on flat ITO. The major factors that currently limit the application are the still low thickness of the mesoporous ITO films, too small pore sizes and non-ideal geometries that do not allow obtaining full coverage of the ITO surface with ZnO before pore blocking occurs. PMID:28788618

Radiation degradation and hemolytic toxicity evaluation of mono azo reactive dyes

International Nuclear Information System (INIS)

Saeed, Q.U.; Bhatti, I.A.; Ashraf, A.

2017-01-01

Monoazo reactive dyes have been synthesized and subjected to degradation before their application. Advanced oxidation process has been recognized as a promising radiation technology for the remediation of hazardous organic compounds. Radiation induced degradation of two mono azo reactive dyes have been tried at different absorbed dose, 5 kGy,10 kGy and 15 kGy. Aqueous solutions of these dyes were treated with gamma radiation using Cs 137 radiation source at Nuclear Institute of Agriculture and Biology (NIAB) Faisalabad. Dyes were evaluated spectrophotometrically by UV-visible and fourier transform infra red (FT-IR) spectroscopic techniques before and after irradiation to analyse their percentage decolorization and degradation. Maximum percentage decolorization of 93% and 63% was achieved for mono azo dyes D1 and D2 at 15 kGy absorbed dose. Toxicity study of these dyes was also tested by haemolytic activity assay. Percentage haemolytic activity of untreated dyes was found within permissible limit showing non toxicity of dye solutions. (author)

Hair follicle stem cell proliferation, Akt and Wnt signaling activation in TPA-induced hair regeneration.

Science.gov (United States)

Qiu, Weiming; Lei, Mingxing; Zhou, Ling; Bai, Xiufeng; Lai, Xiangdong; Yu, Yu; Yang, Tian; Lian, Xiaohua

2017-06-01

Regeneration of hair follicles relies on activation of hair follicle stem cells during telogen to anagen transition process in hair cycle. This process is rigorously controlled by intrinsic and environmental factors. 12-o-tetradecanoylphorbol-13-acetate (TPA), a tumor promoter, accelerates reentry of hair follicles into anagen phase. However, it is unclear that how TPA promotes the hair regeneration. In the present study, we topically applied TPA onto the dorsal skin of 2-month-old C57BL/6 female mice to examine the activity of hair follicle stem cells and alteration of signaling pathways during hair regeneration. We found that refractory telogen hair follicles entered anagen prematurely after TPA treatment, with the enhanced proliferation of CD34-positive hair follicle stem cells. Meanwhile, we observed Akt signaling was activated in epidermis, hair infundibulum, bulge and hair bulb, and Wnt signaling was also activated after hair follicle stem cells proliferation. Importantly, after overexpression of DKK1, a specific Wnt signaling inhibitor, the accelerated reentry of hair follicles into anagen induced by TPA was abolished. Our data indicated that TPA-induced hair follicle regeneration is associated with activation of Akt and Wnt/β-catenin signaling.

Sensitization of Nanocrystalline Metal Oxides with a Phosphonate-Functionalized Perylene Diimide for Photoelectrochemical Water Oxidation with a CoOx Catalyst.

Science.gov (United States)

Kirner, Joel T; Finke, Richard G

2017-08-23

A planar organic thin film composed of a perylene diimide dye (N,N'-bis(phosphonomethyl)-3,4,9,10-perylenediimide, PMPDI) with photoelectrochemically deposited cobalt oxide (CoO x ) catalyst was previously shown to photoelectrochemically oxidize water (DOI: 10.1021/am405598w). Herein, the same PMPDI dye is studied for the sensitization of different nanostructured metal oxide (nano-MO x ) films in a dye-sensitized photoelectrochemical cell architecture. Dye adsorption kinetics and saturation decreases in the order TiO 2 > SnO 2 ≫ WO 3 . Despite highest initial dye loading on TiO 2 films, photocurrent with hydroquinone (H 2 Q) sacrificial reductant in pH 7 aqueous solution is much higher on SnO 2 films, likely due to a higher driving force for charge injection into the more positive conduction band energy of SnO 2 . Dyeing conditions and SnO 2 film thickness were subsequently optimized to achieve light-harvesting efficiency >99% at the λ max of the dye, and absorbed photon-to-current efficiency of 13% with H 2 Q, a 2-fold improvement over the previous thin-film architecture. A CoO x water-oxidation catalyst was photoelectrochemically deposited, allowing for photoelectrochemical water oxidation with a faradaic efficiency of 31 ± 7%, thus demonstrating the second example of a water-oxidizing, dye-sensitized photoelectrolysis cell composed entirely of earth-abundant materials. However, deposition of CoO x always results in lower photocurrent due to enhanced recombination between catalyst and photoinjected electrons in SnO 2 , as confirmed by open-circuit photovoltage measurements. Possible future studies to enhance photoanode performance are discussed, including alternative catalyst deposition strategies or structural derivatization of the perylene dye.

Hair loss in infancy.

Science.gov (United States)

Moreno-Romero, J A; Grimalt, R

2014-02-01

Hair diseases represent a significant portion of cases seen by pediatric dermatologists although hair has always been a secondary aspect in pediatricians and dermatologists training, on the erroneous basis that there is not much information extractable from it. Dermatologists are in the enviable situation of being able to study many disorders with simple diagnostic techniques. The hair is easily accessible to examination but, paradoxically, this approach is often disregarded by non-dermatologist. This paper has been written on the purpose of trying to serve in the diagnostic process of daily practice, and trying to help, for example, to distinguish between certain acquired and some genetically determined hair diseases. We will focus on all the data that can be obtained from our patients' hair and try to help on using the messages given by hair for each patient. Quite often it is extremely hard to distinguish between abnormality and normality in neonatal hair aspects. We will specially focus in the most common physiological changes that may mislead to an incorrect diagnosis. Specific treatment for those hair diseases that do have one, and basic general approach to improve the cosmetic appearance of hair, will be also be discussed for those hair disturbances that do not have a specific treatment.

Hair loss in women.

Science.gov (United States)

Harfmann, Katya L; Bechtel, Mark A

2015-03-01

Hair loss is a common cause of morbidity for many women. As a key member of the woman's health care team, the obstetrician/gynecologist may be the first person to evaluate the complaint of hair loss. Common types of nonscarring hair loss, including female pattern hair loss and telogen effluvium, may be diagnosed and managed by the obstetrician/gynecologist. A systematic approach to diagnosis and management of these common forms of hair loss is presented.

Hair casts

OpenAIRE

Sweta S Parmar; Kirti S Parmar; Bela J Shah

2014-01-01

Hair casts or pseudonits are circumferential concretions, which cover the hair shaft in such a way that, it could be easily removed. They are thin, cylindrical, and elongated in length. We present an unusual case of an 8-year-old girl presenting with hair casts. Occurrence of these is unusual, and they may have varied associations. This patient was suffering from developmental delay. It is commonly misdiagnosed as and very important to differentiate from pediculosis capitis.

Preparation and performance of TiO{sub 2}-ZnO/CNT hetero-nanostructures applied to photodegradation of organic dye

Energy Technology Data Exchange (ETDEWEB)

Da Dalt, Silvana; Alves, Annelise Kopp; Bergmann, Carlos Perez, E-mail: silvana.da.dalt@ufrgs.br [Universidade Federal do Rio Grande so Sul (UFRGS), Porto Alegre, RS (Brazil)

2016-11-15

Water pollution by organic compounds is one of the major challenges faced by industries that use dyeing processes. Thus, some methods were developed for degrading dyes in wastewaters, including heterogeneous photocatalysis by semiconductor oxides. However, these oxides have limited photocatalytic activity due to the fast recombination of photogenerated electron-hole pairs. The aim of this study is the use of a carbon nanotube (CNT) and TiO{sub 2} -ZnO oxide junction from modified sol-gel method to promote the degradation of organic dye through the photocatalytic activity of these nanocomposites. TiO{sub 2} -ZnO/CNT nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) and photocatalytic decomposition of organic dyes. The results of photocatalysis show up to 60% the efficiency of the samples in the removal of dye. (author)

Hair removal in adolescence

Directory of Open Access Journals (Sweden)

Sandra Pereira

2015-06-01

Full Text Available Introduction: Due to hormonal stimulation during puberty, changes occur in hair type and distribution. In both sexes, body and facial unwanted hair may have a negative psychological impact on the teenager. There are several available methods of hair removal, but the choice of the most suitable one for each individual can raise doubts. Objective: To review the main methods of hair removal and clarify their indications, advantages and disadvantages. Development: There are several removal methods currently available. Shaving and depilation with chemicals products are temporary methods, that need frequent repetition, because hair removal is next to the cutaneous surface. The epilating methods in which there is full hair extraction include: epilation with wax, thread, tweezers, epilating machines, laser, intense pulsed light, and electrolysis. Conclusions: The age of beginning hair removal and the method choice must be individualized and take into consideration the skin and hair type, location, dermatological and endocrine problems, removal frequency, cost and personal preferences.

Adsorption mechanism and kinetics of azo dye chemicals on oxide nanotubes: a case study using porous CeO{sub 2} nanotubes

Energy Technology Data Exchange (ETDEWEB)

Wu, Junshu; Wang, Jinshu, E-mail: wangjsh@bjut.edu.cn; Du, Yucheng; Li, Hongyi; Jia, Xinjian [Beijing University of Technology, School of Materials Science and Engineering (China)

2016-07-15

Metal oxide nanotubes are believed to be promising materials with adsorption functionality for water purification due to their synergistic effect of the overall microscale morphology for easy separation and nanoscale surface characters providing enough surface active absorption sites. This work shows the synthesis of uniform hierarchical porous CeO{sub 2} nanotubes via nanowire-directed templating method and describes the adsorption behavior of CeO{sub 2} nanotubes for a typical azo dye Congo red which has resistance to oxidation and decoloration in natural conditions. Fourier transform infrared spectroscopy spectra provided the evidence that Congo red was successfully coated on the surface of CeO{sub 2} nanotubes by both bidentate-type bridge link of Ce{sup 4+} cations from sulfonate SO{sub 3}{sup −} groups and the electrostatic attraction between the protonated surface generated by oxygen vacancies and dissociated sulfonate groups. The adsorption kinetic data fitted well to the pseudo-second-order kinetic equation, whereas the Langmuir isotherm equation exhibited better correlation with the experimental data. The calculated maximum adsorption capacity from the isothermal model was 362.32 mg/g. In addition, the prepared CeO{sub 2} nanotubes exhibited good recyclability and reusability as highly efficient adsorbents for Congo red removal after regeneration. These favorable performances enable the obtained CeO{sub 2} nanotubes to be promising materials for dye removal from aqueous solution.Graphical AbstractCeO{sub 2} nanotubes composed of crystallized nanoparticles exhibit well adsorption ability for a typical azo dye Congo red.

Identification of Colored Dyes that are Resistant to Fading on Exposure to Ethylene Oxide; Use with Indicating FTA™ Sample Collection Cards

Directory of Open Access Journals (Sweden)

Nina Moran

2016-01-01

Full Text Available Regulatory Standards and Forensic Communities are expressing an expectation for HID products to be certified as “DNA-free.” Recently, “DNA-free” status was described for HID-related products using ethylene oxide (EtO; this gas reduces the presence of amplifiable DNA and causes minimal interference to downstream HID-analytical methods. During sample collection, indicating cards, for example, Indicating FTA™ (GE Healthcare Life Sciences, UK, are used to collect and store buccal cell DNA. These cards contain a dye which changes color on application of a colorless sample. Generating “DNA-free” indicating cards using EtO should not impact the dyes' ability to indicate sample location or the efficacy of the card in downstream HID-analytical methods. This study was initiated to identify alternative dyes to those currently used with sample indicating collection cards. The most promising, dyes when applied to cellulose papers exhibited a uniform color distribution and excellent sample indicating properties even when mixed with chemicals associated with FTA™. When dyed cellulose papers were exposed to EtO, ultraviolet radiation, elevated temperature, and humidity, negligible fading or discoloration was observed. The presence of these dyes on cellulose papers did not interfere with direct short tandem repeat (STR profiling. Allelic concordance, first pass success rate, and mean peak heights were comparable to samples applied to Indicating FTA. Biological samples applied to EtO-treated dyed cellulose papers and stored >1 month produced full STR profiles of sufficient quality to allow submission to DNA databases, confirming negligible interference from EtO treatment. These alternative sample indicating dyes resist EtO-mediated fading while fulfilling the Forensic Community's expectation for “DNA-free” with negligible impact on collection card performance.

Electrochemical oxidation of acid black 210 dye on the boron-doped diamond electrode in the presence of phosphate ions: Effect of current density, pH, and chloride ions

International Nuclear Information System (INIS)

Costa, Carla Regina; Montilla, Francisco; Morallon, Emilia; Olivi, Paulo

2009-01-01

The electrochemical oxidation of acid black 210 dye (AB-210) on the boron-doped diamond (BDD) was investigated under different pH conditions. The best performance for the AB-210 oxidation occurred in alkaline phosphate solution. This is probably due to oxidizing agents such as phosphate radicals and peroxodiphosphate ions, which can be electrochemically produced with good yields on the BDD anode, mainly in alkaline solution. Under this condition, the COD (chemical oxygen demand) removal was higher than that obtained from the model proposed by Comninellis. Electrolyses performed in phosphate buffer and in the presence of chloride ions resulted in faster COD and color removals in acid and neutral solutions, but in alkaline phosphate solution, a better performance in terms of TOC removal was obtained in the absence of chloride. Moreover, organochloride compounds were detected in all electrolyses performed in the presence of chloride. The AB-210 electrooxidation on BDD using phosphate as supporting electrolyte proved to be interesting since oxidizing species generated from phosphate ions were able to completely degrade the dye without producing organochloride compounds.

Expression and localization of VEGFR-2 in hair follicles during induced hair growth in mice.

Science.gov (United States)

Wu, Xian-Jie; Jing, Jing; Lu, Zhong-Fa; Zheng, Min

2018-06-16

Recently, VEGFR-2 has been detected not only in vascular and lymphatic endothelial cells but also in some non-vascular endothelial cells, particularly human hair follicles, sebaceous glands, and sweat glands. In addition, VEGFR-2 has been confirmed to play direct roles in hair follicle keratinocyte regulation beyond simply angiogenesis. To elucidate whether VEGFR-2 activation plays a role in hair follicle cycling regulation, immunofluorescence of VEGFR-2 expression was performed during hair cycling of the dorsum of the mouse induced by hair plucking. We observed that staining for VEGFR-2 in hair follicles during anagen II and IV was much stronger than during anagen VI, catagen and telogen. During anagen II, intense staining for VEGFR-2 was observed on the keratinocyte strands of the hair follicle. Subsequently, we detected intense staining for VEGFR-2 in the ORS, IRS and hair bulb during anagen IV. Moderate staining for VEGFR-2 was detected in the ORS and hair bulb, but staining was most intense in IRS during anagen VI. During catagen, staining for VEGFR-2 in the IRS remained intense, while staining in the ORS and hair bulb was significantly weakened and was negative in the dermal papilla. During telogen, we detected VEGFR-2 in germ cells, cap, and club hair adjoining the epidermis. In conclusion, VEGFR-2 was expressed on the hair follicles of the dorsum of the mouse and varied in expression on the mouse hair follicles during hair cycling, suggesting that VEGFR-2 may exert roles in hair cycle regulation in hair follicles on the dorsum of mice.

Whole-cell fungal transformation of precursors into dyes

Directory of Open Access Journals (Sweden)

Jarosz-Wilkołazka Anna

2010-07-01

Full Text Available Abstract Background Chemical methods of producing dyes involve extreme temperatures and unsafe toxic compounds. Application of oxidizing enzymes obtained from fungal species, for example laccase, is an alternative to chemical synthesis of dyes. Laccase can be replaced by fungal biomass acting as a whole-cell biocatalyst with properties comparable to the isolated form of the enzyme. The application of the whole-cell system simplifies the transformation process and reduces the time required for its completion. In the present work, four fungal strains with a well-known ability to produce laccase were tested for oxidation of 17 phenolic and non-phenolic precursors into stable and non-toxic dyes. Results An agar-plate screening test of the organic precursors was carried out using four fungal strains: Trametes versicolor, Fomes fomentarius, Abortiporus biennis, and Cerrena unicolor. Out of 17 precursors, nine were transformed into coloured substances in the presence of actively growing fungal mycelium. The immobilized fungal biomass catalyzed the transformation of 1 mM benzene and naphthalene derivatives in liquid cultures yielding stable and non-toxic products with good dyeing properties. The type of fungal strain had a large influence on the absorbance of the coloured products obtained after 48-hour transformation of the selected precursors, and the most effective was Fomes fomentarius (FF25. Whole-cell transformation of AHBS (3-amino-4-hydroxybenzenesulfonic acid into a phenoxazinone dye was carried out in four different systems: in aqueous media comprising low amounts of carbon and nitrogen source, in buffer, and in distilled water. Conclusions This study demonstrated the ability of four fungal strains belonging to the ecological type of white rot fungi to transform precursors into dyes. This paper highlights the potential of fungal biomass for replacing isolated enzymes as a cheaper industrial-grade biocatalyst for the synthesis of dyes and other

Rapid and efficient visible light photocatalytic dye degradation using AFe{sub 2}O{sub 4} (A = Ba, Ca and Sr) complex oxides

Energy Technology Data Exchange (ETDEWEB)

Vijayaraghavan, T. [PSG Institute of Advanced Studies, Coimbatore 641004 (India); Suriyaraj, S.P.; Selvakumar, R. [Nanobiotechnology Laboratory, PSG Institute of Advanced Studies, Coimbatore 641004 (India); Venkateswaran, R. [PSG Institute of Advanced Studies, Coimbatore 641004 (India); Ashok, Anuradha, E-mail: anu@psgias.ac.in [PSG Institute of Advanced Studies, Coimbatore 641004 (India)

2016-08-15

Highlights: • Alkaline earth ferrites AFe{sub 2}O{sub 4} (A = Ba, Ca and Sr) were synthesized by sol–gel method. • Visible light photocatalytic activity of these ferrites were studied using congo red dye degradation. • BaFe{sub 2}O{sub 4} exhibited the best photocatalytic activity under visible light (xenon lamp) irradiation; CaFe{sub 2}O{sub 4} was the best photocatalyst under natural sun light irradiation. - Abstract: Photocatalytic activity of spinel type complex oxides has been investigated in this study. Alkaline earth ferrites AFe{sub 2}O{sub 4} (A = Ba, Ca, Sr) were synthesized by sol–gel method. Structural characterizations reveal that the synthesized ferrites have orthorhombic crystal structures with different space groups and cell dimensions when they have different alkaline earth metals in their A site. All the synthesized ferrites exhibited their bandgap in the range 2.14–2.19 eV. Their photocatalytic activities were studied using congo red dye under sunlight and xenon lamp radiation. The substitution of Ba, Ca and Sr at A site of these ferrites had varying impact on dye degradation process. Under xenon lamp irradiation, BaFe{sub 2}O{sub 4} exhibited the highest percentage of dye degradation (92% after 75 min). However, CaFe{sub 2}O{sub 4} showed the fastest degradation of the dye (70% within 15 min). In the absence of irradiation, SrFe{sub 2}O{sub 4} showed the highest dye adsorption (44% after 75 min).

Minocycline attenuates streptomycin-induced cochlear hair cell death by inhibiting protein nitration and poly (ADP-ribose) polymerase activation.

Science.gov (United States)

Wang, Ping; Li, Haonan; Yu, Shuyuan; Jin, Peng; Hassan, Abdurahman; Du, Bo

2017-08-24

This study aimed to elucidate the protective effect of minocycline against streptomycin-induced damage of cochlear hair cells and its mechanism. Cochlear membranes were isolated from newborn Wistar rats and randomly divided into control, 500μmol/L streptomycin, 100μmol/L minocycline, and streptomycin and minocycline treatment groups. Hair cell survival was analyzed by detecting the expression of 3-nitrotyrosine (3-NT) in cochlear hair cells by immunofluorescence and an enzyme-linked immunosorbent assay. Expression of 3-NT and inducible nitric oxide synthase (iNOS), and poly (ADP-Ribose) polymerase (PARP) and caspase-3 activation were evaluated by western blotting. The results demonstrated hair cell loss at 24h after streptomycin treatment. No change was found in supporting cells of the cochleae. Minocycline pretreatment improved hair cell survival and significantly reduced the expression of iNOS and 3-NT in cochlear tissues compared with the streptomycin treatment group. PARP and caspase-3 activation was increased in the streptomycin treatment group compared with the control group, and pretreatment with minocycline decreased cleaved PARP and activated caspase-3 expression. Minocycline protected cochlear hair cells from injury caused by streptomycin in vitro. The mechanism underlying the protective effect may be associated with the inhibition of excessive formation of nitric oxide, reduction of the nitration stress reaction, and inhibition of PARP and caspase-3 activation in cochlear hair cells. Combined minocycline therapy can be applied to patients requiring streptomycin treatment. Copyright © 2017. Published by Elsevier B.V.

Radiolysis of organic triphenylmethane, anthraquinone, xanthene, oxazine, thiazine, and azo dyes in polymers films

International Nuclear Information System (INIS)

Khabarov, V.N.; Kozlov, L.L.; Molin, A.A.; Mekhanik, T.V.

1989-01-01

The effect of the oxygen in the air and the temperature on radiochemical processes of decolorization of triphenylmethane, anthraquinone, xanthene, oxazine, thiazine, and azo dyes in polymer matrices of different chemical natures was studied. The rate of radiation decolorization for most of the dyes increases in irradiation in the presence of O 2 , which is hypothetically due to oxidation of the dye by singlet oxygen. The organic dyes exhibit the highest radiation stability in polyethylene terephthalate and polystyrene films

"I think gorilla-like back effusions of hair are rather a turn-off": 'Excessive hair' and male body hair (removal) discourse.

Science.gov (United States)

Terry, Gareth; Braun, Virginia

2016-06-01

Men's hair removal practices are becoming mainstream, seen as a consequence of changing masculine norms and men's relationships to their bodies. This is often presented as a straightforward 'shift' from men's ideal bodies as naturally hairy, to increased hairlessness, and the consequence on men's body concerns as inevitable. This paper analyses qualitative survey data from Aotearoa/New Zealand using critical thematic analysis, and describes three themes. Two themes capture contradictory ideas: that men's body hair is natural, and that men's body hair is unpleasant. A third theme introduces the concept of 'excess' hair, which allowed sense-making of this contradiction, mandating men's grooming of 'excessive' hair. However its vagueness as a concept may provoke anxiety for men resulting in hair removal. This paper adds to a body of research demonstrating a cultural transition: the ways changing masculinities, increased commodification of male bodies, and shifting gender roles impact on men's hair removal practices. Copyright © 2016 Elsevier Ltd. All rights reserved.

Laccase/mediator assisted degradation of triarylmethane dyes in a continuous membrane reactor.

Science.gov (United States)

Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

2009-08-10

Laccase/mediator systems are important bioremediation agents as the rates of reactions can be enhanced in the presence of the mediators. The decolorization mechanism of two triarylmethane dyes, namely, Basic Green 4 and Acid Violet 17 is reported using Cyathus bulleri laccase. Basic Green 4 was decolorized through N-demethylation by laccase alone, while in mediator assisted reactions, dye breakdown was initiated from oxidation of carbinol form of the dye. Benzaldehyde and N,N-dimethyl aniline were the major end products. With Acid Violet 17, laccase carried out N-deethylation and in mediator assisted reactions, oxidation of the carbinol form of the dye occurred resulting in formation of formyl benzene sulfonic acid, carboxy benzene sulfonic acid and benzene sulfonic acid. Toxicity analysis revealed that Basic Green 4 was toxic and treatment with laccase/mediators resulted in 80-100% detoxification. The treatment of the textile dye solution using laccase and 2,2'-azino-di-(-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was demonstrated in an enzyme membrane reactor. At a hydraulic retention time of 6h, the process was operated for a period of 15 days with nearly 95% decolorization, 10% reduction in flux and 70% recovery of active ABTS.

Hair cycle in dogs with different hair types in a tropical region of Brazil.

Science.gov (United States)

Favarato, Evandro S; Conceição, Lissandro Gonçalves

2008-02-01

Hair cycle activity has been extensively studied in humans, sheep and laboratory animals, but there is a lack of information in dogs. Besides varying according to species, breed, sex and general health, hair growth is mainly affected by climatic variations. The aim of the study was to evaluate the follicle activity in three breeds of dogs with different hair types, in the city of Viçosa, Minas Gerais (latitude 20 degrees 45'S), Brazil. Twenty-one male dogs of boxer, labrador and schnauzer breeds were trichographically analysed monthly over 12 consecutive months. Hair percentage of telogen and anagen hairs at the different stages of the hair cycle in boxers and labradors was not significantly different, but both differed from the schnauzers. A significant correlation between hair follicle cycle and environmental temperature and photoperiod was noted in the boxers and labradors. In these breeds, a larger number of telogen hairs were observed during the hottest months of the year, and an increase in anagen hairs during the coldest months. The mean percentage of telogen hairs was 93, 90 and 55.3% for boxer, labrador and schnauzer, respectively.

For the Fenton process in a sequential downflow and upflow system to treat textile dyeing wastewater

Energy Technology Data Exchange (ETDEWEB)

Bae, W.K.; Ko, G.B.; Cho, S.J. [Dept. of Civil and Environmental Engineering, Hanyang Univ., Kyounggi (Korea); Lee, S.H. [Dept. of Environmental Engineering, Sangmyung Univ., Cheonan (Korea)

2003-07-01

Wastewater from textile dyeing industry is characterized by high temperature, pH, pollution loading such as color and COD which are containing refractory, toxic and high molecular weight compounds. It is therefore, presumed to be very resistant to microbial degradation. Textile dyeing wastewater is therefore, presumed to be very resistant to microbial degradation. Combined processes are usually applied, which are chemical oxidation and biological process for textile dyeing wastewater in order to satisfy water quality standards. Fenton process as advanced oxidation process is well known as effective process for the removal of color and recalcitrant organics. However, the exactly predominant reaction mechanisms during Fenton process are not well explained among coagulation, oxidation and sedimentation so far. This research attempts to evaluate the predominant reaction with comparable results of ferric coagulation and oxidation for the Fenton process. (orig.)

Investigation of electronic band structure and charge transfer mechanism of oxidized three-dimensional graphene as metal-free anodes material for dye sensitized solar cell application

Science.gov (United States)

Loeblein, Manuela; Bruno, Annalisa; Loh, G. C.; Bolker, Asaf; Saguy, Cecile; Antila, Liisa; Tsang, Siu Hon; Teo, Edwin Hang Tong

2017-10-01

Dye-sensitized solar cells (DSSCs) offer an optimal trade-off between conversion-efficiency and low-cost fabrication. However, since all its electrodes need to fulfill stringent work-function requirements, its materials have remained unchanged since DSSC's first report early-90s. Here we describe a new material, oxidized-three-dimensional-graphene (o-3D-C), with a band gap of 0.2 eV and suitable electronic band-structure as alternative metal-free material for DSSCs-anodes. o-3D-C/dye-complex has a strong chemical bonding via carboxylic-group chemisorption with full saturation after 12 sec at capacity of ∼450 mg/g (600x faster and 7x higher than optimized metal surfaces). Furthermore, fluorescence quenching of life-time by 28-35% was measured demonstrating charge-transfer from dye to o-3D-C.

A highly effective in vivo photothermal nanoplatform with dual imaging-guided therapy of cancer based on the charge reversal complex of dye and iron oxide

NARCIS (Netherlands)

Chang, Y.; Li, X.; Kong, X.; Li, Y.; Liu, X.; Zhang, Y.; Tu, L.; Xue, B.; Wu, F.; Cao, D.; Zhao, H.; Zhang, H.

2015-01-01

To enhance the treatment efficiency of photothermal therapy (PTT) with very little light-associated side effect, we have constructed a highly effective PTT nanoplatform for fluorescence and MRI dual imaging-guided PTT of cancer, based on IR806 dye and iron oxide complex functionalized with

Structural Properties of Zinc Oxide Nanorods Grown on Al-Doped Zinc Oxide Seed Layer and Their Applications in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Kyung Ho Kim

2014-03-01

Full Text Available We fabricated zinc oxide (ZnO nanorods (NRs with Al-doped ZnO (AZO seed layers and dye-sensitized solar cells (DSSCs employed the ZnO NRs between a TiO2 photoelectrode and a fluorine-doped SnO2 (FTO electrode. The growth rate of the NRs was strongly dependent on the seed layer conditions, i.e., thickness, Al dopant and annealing temperature. Attaining a large particle size with a high crystallinity of the seed layer was vital to the well-aligned growth of the NRs. However, the growth was less related to the substrate material (glass and FTO coated glass. With optimized ZnO NRs, the DSSCs exhibited remarkably enhanced photovoltaic performance, because of the increase of dye absorption and fast carrier transfer, which, in turn, led to improved efficiency. The cell with the ZnO NRs grown on an AZO seed layer annealed at 350 °C showed a short-circuit current density (JSC of 12.56 mA/cm2, an open-circuit voltage (VOC of 0.70 V, a fill factor (FF of 0.59 and a power conversion efficiency (PCE, η of 5.20% under air mass 1.5 global (AM 1.5G illumination of 100 mW/cm2.

Drug-induced hair loss.

Science.gov (United States)

2016-05-01

Hair loss can have major psychological consequences. It can be due to a wide variety of causes, including hormonal disorders, dietary factors, infections, inflammation, trauma, emotional factors, and cancer. Drugs can also induce hair loss, by interacting with the hair growth cycle. Drug-induced hair loss may be immediate or delayed, sudden or gradual, and diffuse or localised. It is usually reversible after drug discontinuation. The drugs most often implicated in hair loss are anticancer agents, interferon, azole antifungals, lithium, immunosuppressants, and many other drugs belonging to a variety of pharmacological classes.

Loose anagen hair syndrome with diffuse woolly hair phenotype: A rare association

Directory of Open Access Journals (Sweden)

Arshdeep

2016-01-01

Full Text Available Loose anagen hair syndrome (LAHS is an underestimated cause of noncicatricial alopecia among children, manifesting as thin, sparse or fine hair. We report a case of LAHS clinically presenting as diffuse woolly hair, an association rarely described in the literature. In addition, we review the clinical as well as genetic link between these two enigmatic hair disorders and hypothesize that both may be associated in a yet unknown manner.

Drugs and hair loss.

Science.gov (United States)

Patel, Mansi; Harrison, Shannon; Sinclair, Rodney

2013-01-01

Hair loss is a common complaint, both in men and women, and use of prescription medications is widespread. When there is a temporal association between the onset of hair loss and commencement of a medication, the medication is commonly thought to have caused the hair loss. However, hair loss and in particular telogen effluvium may occur in response to a number of triggers including fever, hemorrhage, severe illness, stress, and childbirth, and a thorough exclusion of these potential confounders is necessary before the hair loss can be blamed on the medication. Certain medications are known to cause hair loss by a variety of mechanisms including anagen arrest, telogen effluvium, or accentuation of androgenetic alopecia by androgens. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Fabrication of Polymeric Antireflection Film Manufactured by Anodic Aluminum Oxide Template on Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Jenn-Kai Tsai

2017-03-01

Full Text Available In this study, high energy conversion efficient dye-sensitized solar cells (DSSCs were successfully fabricated by attaching a double anti-reflection (AR layer, which is composed of a subwavelength moth-eye structured polymethyl methacrylate (PMMA film and a polydimethylsiloxane (PDMS film. An efficiency of up to 6.79% was achieved. The moth-eye structured PMMA film was fabricated by using an anodic aluminum oxide (AAO template which is simple, low-cost and scalable. The nano-pattern of the AAO template was precisely reproduced onto the PMMA film. The photoanode was composed of Titanium dioxide (TiO2 nanoparticles (NPs with a diameter of 25 nm deposited on the fluorine-doped tin oxide (FTO glass substrate and the sensitizer N3. The double AR layer was proved to effectively improve the short-circuit current density (JSC and conversion efficiency from 14.77 to 15.79 mA/cm2 and from 6.26% to 6.79%, respectively.

S-nitrosoglutathione promotes cell wall remodelling, alters the transcriptional profile and induces root hair formation in the hairless root hair defective 6 (rhd6) mutant of Arabidopsis thaliana.

Science.gov (United States)

Moro, Camila Fernandes; Gaspar, Marilia; da Silva, Felipe Rodrigues; Pattathil, Sivakumar; Hahn, Michael G; Salgado, Ione; Braga, Marcia Regina

2017-03-01

Nitric oxide (NO) exerts pleiotropic effects on plant development; however, its involvement in cell wall modification during root hair formation (RHF) has not yet been addressed. Here, mutants of Arabidopsis thaliana with altered root hair phenotypes were used to assess the involvement of S-nitrosoglutathione (GSNO), the primary NO source, in cell wall dynamics and gene expression in roots induced to form hairs. GSNO and auxin restored the root hair phenotype of the hairless root hair defective 6 (rhd6) mutant. A positive correlation was observed between increased NO production and RHF induced by auxin in rhd6 and transparent testa glabra (ttg) mutants. Deposition of an epitope within rhamnogalacturonan-I recognized by the CCRC-M2 antibody was delayed in root hair cells (trichoblasts) compared with nonhair cells (atrichoblasts). GSNO, but not auxin, restored the wild-type root glycome and transcriptome profiles in rhd6, modulating the expression of a large number of genes related to cell wall composition and metabolism, as well as those encoding ribosomal proteins, DNA and histone-modifying enzymes and proteins involved in post-translational modification. Our results demonstrate that NO plays a key role in cell wall remodelling in trichoblasts and suggest that it also participates in chromatin modification in root cells of A. thaliana. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Dye-Sensitized Approaches to Photovoltaics

Science.gov (United States)

Grätzel, Michael

2008-03-01

Sensitization of wide band-gap semiconductors to photons of energy less than the band-gap is a key step in two technically important processes - panchromatic photography and photoelectrochemical solar cells. In both cases the photosensitive species is not the semiconductor - silver halide or metal oxide - but rather an electrochemically active dye. The gap between the highest occupied molecular level (HOMO) and the lowest unoccupied molecular level (LUMO) is less than the band-gap of the semiconductor with which it is associated. It can therefore absorb light of a wavelength longer than that to which the semiconductor itself is sensitive. The electrochemical process is initiated when the dye molecule relaxes from its photoexcited level by electron injection into the semiconductor, which therefore acts as a photoanode. If the dye is in contact with a redox electrolyte, the negative charge represented by the lost electron can be recovered from the reduced state of the redox system, which in return is regenerated by charge transfer from a cathode. An external load completes the electrical circuit. The system therefore represents a conversion of the energy of absorbed photons into an electrical current by a regenerative device in every functional respect analogous to a solid-state photovoltaic cell. As in any engineering system, choice of materials, their optimization and their synergy are essential to efficient operation. While a semiconductor-electrolyte contact is analogous to a Schottky contact, in that a barrier is established between two materials of different conduction mechanism, with the possibility of optical absorption, charge carrier pair generation and separation, it should be remembered that the photogenerated valence band hole in the semiconductor represents a powerful oxidizing agent. Given that the band-gap is related to the strength and therefore the stability of chemical bonding within the semiconductor, for narrow-gap materials the most likely

Combination of Asymmetric Supercapacitor Utilizing Activated Carbon and Nickel Oxide with Cobalt Polypyridyl-Based Dye-Sensitized Solar Cell

International Nuclear Information System (INIS)

Bagheri, Narjes; Aghaei, Alireza; Ghotbi, Mohammad Yeganeh; Marzbanrad, Ehsan; Vlachopoulos, Nick; Häggman, Leif; Wang, Michael; Boschloo, Gerrit; Hagfeldt, Anders; Skunik-Nuckowska, Magdalena; Kulesza, Pawel J.

2014-01-01

Highlights: • Dye Solar Cell and supercapacitor are integrated into a single device capable of generation and storage of energy. • The solar cell part of the device utilizes the Co-based electrolyte and nickel/PEDOT counter electrode. • A cobalt-doped nickel oxide together with activated carbon is used in the capacitor part of the device. • The integrated photocapacitor is characterized by the capacitance of 32 F g −1 and the total efficiency of 0.6%. - Abstract: A dye-sensitized solar cell (DSC) based on the metal-free organic sensitizer and the cobalt (II, III) polypyridyl electrolyte was integrated here within an asymmetric supercapacitor utilizing cobalt-doped nickel oxide and activated carbon as positive and negative electrodes, respectively. A low cost nickel foil served as intermediate (auxiliary) bifunctional electrode separating two parts of the device and permitting the DSC electrolyte regeneration at one side and charge storage within cobalt-doped nickel oxide at the other. The main purpose of the research was to develop an integrated photocapacitor system capable of both energy generation and its further storage. Following irradiation at the 100 mW cm −2 level, the solar cell generated an open-circuit voltage of 0.8 V and short-circuit current of 8 mA cm −2 which corresponds to energy conversion efficiency of 4.9%. It was further shown that upon integration with asymmetric supercapacitor, the photogenerated energy was directly injected into porous charge storage electrodes thus resulting in specific capacitance of 32 F g −1 and energy density of 2.3 Wh kg −1 . The coulumbic and total (energy conversion and charge storage) efficiency of photocapacitor were equal to 54% and 0.6%, respectively

Optical hair removal.

Science.gov (United States)

Ort, R J; Anderson, R R

1999-06-01

Traditional methods of hair removal have proven unsatisfactory for many individuals with excessive or unwanted hair. In the last few years, several lasers and xenon flashlamps have been developed that promise to fulfill the need for a practical, safe, and long-lasting method of hair removal. Aggressive marketing of these has contributed to their popularity among patients and physicians. However, significant controversy and confusion surrounds this field. This article provides a detailed explanation of the scientific underpinnings for optical hair removal and explores the advantages and disadvantages of the various devices currently available (Nd:YAG, ruby, alexandrite, diode lasers, and xenon flashlamp). Treatment and safety guidelines are provided to assist the practitioner in the use of these devices. Although the field of optical hair removal is still in its infancy, initial reports of long-term efficacy are encouraging.

Hair camouflage: A comprehensive review.

Science.gov (United States)

Saed, Stephanie; Ibrahim, Omer; Bergfeld, Wilma F

2017-03-01

Hair is venerated, cherished, and desired in societies throughout the world. Both women and men express their individual identities through their hairstyles. Healthy hair contributes to successful social assimilation, employment, and overall quality of life. Therefore, hair loss can have detrimental effects on almost every aspect of a person's life. In this review, we discuss the myriad of options that aid in concealing and camouflaging hair loss to facilitate a healthier-appearing scalp. Camouflage options for patients who suffer from hair loss include full or partial wigs, hair extensions, concealing powders and sprays, surgical tattoos, and hair transplants. We describe these modalities in detail and discuss their respective advantages and disadvantages.

Artificial Hair: By the Dawn to Automatic Biofibre® Hair Implant

Directory of Open Access Journals (Sweden)

Maria Roccia

2017-12-01

In 1995 the European Union (UE recognised the artificial hair implant as a legitimate medical treatment and outlined the rules related to that procedure. In 1996, biocompatible fibres (Biofibre® produced by Medicap® Italy were approved by the UE Authorities and by the Australian Therapeutic Goods Administration (TGA as medical devices for hair implant. An effective medical protocol was developed during the following years to provide correct guidelines for appropriate treatment, and to reduce possible related complications. Automatic Biofibre® hair implant represents the last achievement in this hair restoration technique with significant advantages for the patients.

Characteristics of thermally reduced graphene oxide and applied for dye-sensitized solar cell counter electrode

Energy Technology Data Exchange (ETDEWEB)

Ho, Ching-Yuan, E-mail: cyho@cycu.edu.tw [Department of Mechanical Engineering, Chung Yuan Christian University, Chung-Li, Taiwan (China); Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung Yuan Christian University, Chung-Li, Taiwan (China); Wang, Hong-Wen [Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung Yuan Christian University, Chung-Li, Taiwan (China); Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taiwan (China)

2015-12-01

Graphical abstract: Experimental process: (1) graphite oxidized to graphene oxide; (2) thermal reduction from graphene oxide to graphene; (3) applying to DSSC counter electrode. - Highlights: • Intercalated defects were eliminated by increasing reduction temperature of GO. • High reduction temperature of tGP has lower resistance, high the electron lifetime. • Higher thermal reduction of GO proposes electrocatalytic properties. • DSSC using tGP{sub 250} as counter electrode has energy conversion efficiency of 3.4%. - Abstract: Graphene oxide (GO) was synthesized from a flake-type of graphite powder, which was then reduced to a few layers of graphene sheets using the thermal reduction method. The surface morphology, phase crystallization, and defect states of the reduced graphene were determined from an electron microscope equipped with an energy dispersion spectrometer, X-ray diffraction, Raman spectroscopy, and infrared spectra. After graphene formation, the intercalated defects that existed in the GO were removed, and it became crystalline by observing impurity changes and d-spacing. Dye-sensitized solar cells, using reduced graphene as the counter electrode, were fabricated to evaluate the electrolyte activity and charge transport performance. The electrochemical impedance spectra showed that increasing the thermal reduction temperature could achieve faster electron transport and longer electron lifetime, and result in an energy conversion efficiency of approximately 3.4%. Compared to the Pt counter electrode, the low cost of the thermal reduction method suggests that graphene will enjoy a wide range of potential applications in the field of electronic devices.

Characteristics of thermally reduced graphene oxide and applied for dye-sensitized solar cell counter electrode

International Nuclear Information System (INIS)

Ho, Ching-Yuan; Wang, Hong-Wen

2015-01-01

Graphical abstract: Experimental process: (1) graphite oxidized to graphene oxide; (2) thermal reduction from graphene oxide to graphene; (3) applying to DSSC counter electrode. - Highlights: • Intercalated defects were eliminated by increasing reduction temperature of GO. • High reduction temperature of tGP has lower resistance, high the electron lifetime. • Higher thermal reduction of GO proposes electrocatalytic properties. • DSSC using tGP 250 as counter electrode has energy conversion efficiency of 3.4%. - Abstract: Graphene oxide (GO) was synthesized from a flake-type of graphite powder, which was then reduced to a few layers of graphene sheets using the thermal reduction method. The surface morphology, phase crystallization, and defect states of the reduced graphene were determined from an electron microscope equipped with an energy dispersion spectrometer, X-ray diffraction, Raman spectroscopy, and infrared spectra. After graphene formation, the intercalated defects that existed in the GO were removed, and it became crystalline by observing impurity changes and d-spacing. Dye-sensitized solar cells, using reduced graphene as the counter electrode, were fabricated to evaluate the electrolyte activity and charge transport performance. The electrochemical impedance spectra showed that increasing the thermal reduction temperature could achieve faster electron transport and longer electron lifetime, and result in an energy conversion efficiency of approximately 3.4%. Compared to the Pt counter electrode, the low cost of the thermal reduction method suggests that graphene will enjoy a wide range of potential applications in the field of electronic devices.

The hair-dye reagent 2-(2',4'-diaminophenoxy)ethanol is mutagenic to Salmonella typhimurium.

Science.gov (United States)

Venitt, S; Crofton-Sleigh, C; Osborne, M R

1984-01-01

A new hair-dye ingredient, 2-(2',4'-diaminophenoxy)ethanol (2,4-DAPE), was described as being devoid of any genotoxic activity on the basis of a multi-laboratory study. Since 2,4-DAPE is a close analogue of 2,4-diaminoanisole (2,4-DAA), which is mutagenic and carcinogenic, we tested this claim by assaying 2,4-DAPE for bacterial mutagenicity. Two samples of 2,4-DAPE X 2HCl were synthesized by reduction of the corresponding dinitrophenoxyethanol and identity and purity were established by elemental analysis, NMR spectrometry, mass-spectrometry, UV-spectrophotometry, TLC and HPLC. Fresh aqueous solutions of 2,4-DAPE X 2HCl were assayed in several separate plate tests using S. typhimurium TA1538, TA97, TA98 and TA100, and E. coli WP2uvrA (pKM101), 3 plates per dose and 0%, 4%, 10% and 30% Aroclor 1254-induced rat-liver S9 in S9 mixes. We obtained negative results in TA100 and E. coli. Reproducible, statistically significant dose-related increases in revertants (up to 14 times the background) were obtained in frame-shift mutants of S. typhimurium in the dose range 10-80 micrograms per plate. Mutagenicity was S9-dependent, significant increases in revertants being obtained only with 50 microliter per plate or more of S9. 2,4-DAPE induced significant mutagenic effects at doses of less than 1 micrograms per ml in TA1538 and TA98 in fluctuation tests using 2% S9 in the S9 mix. In plate tests, 2,4-DAPE was less mutagenic (by a factor of about 8) than 2,4-DAA, which gave the highest mutant yields with 20 microliter S9 per plate (4% S9 in the S9 mix). 2,4-DAPE obtained commercially was about 8 times more mutagenic than our sample of 2,4-DAPE. After purification, the commercial product, now chromatographically identical with our own sample, gave plate-test results close to those obtained for our samples of 2,4-DAPE. A review of the published reports (in which 2,4-DAPE was claimed to be inactive in a variety of short-term tests) revealed: (a) the use of protocols for bacterial

Incorporation of graphene into SnO2 photoanodes for dye-sensitized solar cells

Science.gov (United States)

Batmunkh, Munkhbayar; Dadkhah, Mahnaz; Shearer, Cameron J.; Biggs, Mark J.; Shapter, Joseph G.

2016-11-01

In dye-sensitized solar cell (DSSC) photoanodes, tin dioxide (SnO2) structures present a promising alternative semiconducting oxide to the conventional titania (TiO2), but they suffer from poor photovoltaic (PV) efficiency caused by insufficient dye adsorption and low energy value of the conduction band. A hybrid structure consisting of SnO2 and reduced graphene oxide (SnO2-RGO) was synthesized via a microwave-assisted method and has been employed as a photoanode in DSSCs. Incorporation of RGO into the SnO2 photoanode enhanced the power conversion efficiency of DSSC device by 91.5%, as compared to the device assembled without RGO. This efficiency improvement can be attributed to increased dye loading, enhanced electron transfer and addition of suitable energy levels in the photoanode. Finally, the use of RGO addresses the major shortcoming of SnO2 when employed as a DSSC photoanode, namely poor dye adsorption and slow electron transfer rate.

Microscopy of the hair and trichogram

Directory of Open Access Journals (Sweden)

Özlem Dicle

2014-06-01

Full Text Available Hair microscopy is a fast and simple method for the diagnosis of various disorders affecting the hair in daily practice. For the microscopy of the hair, samples are collected by either clipping or plucking. The trichogram technique which the hair sample is collected by a standardized plucking method is used for the diagnosis of hair shedding and of alopecia via hair root pattern. In this review, the examination techniques and details are discussed and the most common indications for the hair microscopy including hair abnormalities as a part of genodermatosis and, infections and infestations affecting the hair are highlighted.

Telogen Effluvium Hair Loss

Science.gov (United States)

... Category: Share: Yes No, Keep Private Telogen Effluvium Hair Loss Share | It is normal to lose up to ... months after the "shock". This sudden increase in hair loss, usually described as the hair coming out in ...

Taking Care of Your Hair

Science.gov (United States)

... Educators Search English Español Taking Care of Your Hair KidsHealth / For Teens / Taking Care of Your Hair ... role in how healthy it looks. Caring for Hair How you take care of your hair depends ...

Degradation of TiO2 and/or SiO2 hybrid films doped with different cationic dyes

International Nuclear Information System (INIS)

Purcar, Violeta; Caprarescu, Simona; Donescu, Dan; Petcu, Cristian; Stamatin, Ioan; Ianchis, Raluca; Stroescu, Hermine

2013-01-01

Hybrid thin films, silica–titanium oxides and silica–aluminum oxides, designed based on the sol–gel process are evaluated as catalysts in the photo-degradation of the cationic dyes. Silica matrices from different precursors with various organic functional groups and cross-linked with titanium or aluminum agents (tetraisopropyl orthotitanate and aluminum sec-butoxide) allow the surface property tailoring related to the high capacity of the dye adsorption respective, high photo-degradation activity. The cationic dyes (methylene blue, rhodamine B, crystal violet, malachite green) embedded on the hybrid silica matrix, under ultraviolet light, have a first order kinetics of photodegradation. The cross-linking agents play a key role in the photocatalytic degradation and silica matrix as dye absorbent. The photo-degradation rate for the binary system derived from methyltriethoxysilane/vinyltriethoxysilane precursors with both cross linkers showed a significant improvement by comparison with other hybrid materials. The significant increasing in the photodecomposition rate is related to the capacity to generate additional oxidizing species by each silica hybrid compounds. - Highlights: ► Dyes display different electrostatic interactions to the silica matrix. ► Cross-linking agent influences the photocatalytic degradation of dyes. ► Photodegradation reaction obeyed the rules of a pseudo-first-order kinetic reaction. ► UV radiation can be the origin of the photodegradation

Transparent front contact optimization in dye sensitized solar cells: use of cadmium stannate and titanium oxide by sputtering

Energy Technology Data Exchange (ETDEWEB)

Braga, A., E-mail: antonio.braga@iit.it [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy); Baratto, C. [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy); Bontempi, E. [INSTM and Chemistry for Technologies Laboratory, University of Brescia, Via Branze 28, 25133 Brescia (Italy); Colombi, P. [Centro Coating C.S.M.T. Gestione S.c.a.r.l., Via Branze, 45 25123 Brescia (Italy); Sberveglieri, G. [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy)

2014-03-31

A reliable transparent front contact of cadmium stannate (CTO) and titanium oxide (TiO{sub 2}) entirely deposited by magnetron sputtering has been studied and applied to build standard dye-sensitized solar cell. CTO gives very high average optical transmittance (T{sub avg} ≥ 90%) along with competitive sheet resistance (R{sub sheet} ≤ 15 Ω/sq), while a very thin layer of TiO{sub 2} (thickness < 5 nm) acts as buffer layer to prevent charge recombination. The matched materials allow achievement of good performances of the cells, in terms of short circuit current and power conversion efficiency. UV-visible spectrophotometry, glancing incident X-rays diffraction and X-rays reflectivity techniques were used to characterize thin films before cell realization; sealed solar cells were tested under simulated solar irradiance at 1 Sun to determine functional properties. - Highlights: • Double layer cadmium stannate–TiO{sub 2} transparent front contact by sputtering. • Very thin TiO{sub 2} buffer layer for charge recombination prevention. • Application of novel transparent contact in standard dye sensitized solar cells.

Transparent front contact optimization in dye sensitized solar cells: use of cadmium stannate and titanium oxide by sputtering

International Nuclear Information System (INIS)

Braga, A.; Baratto, C.; Bontempi, E.; Colombi, P.; Sberveglieri, G.

2014-01-01

A reliable transparent front contact of cadmium stannate (CTO) and titanium oxide (TiO 2 ) entirely deposited by magnetron sputtering has been studied and applied to build standard dye-sensitized solar cell. CTO gives very high average optical transmittance (T avg ≥ 90%) along with competitive sheet resistance (R sheet ≤ 15 Ω/sq), while a very thin layer of TiO 2 (thickness < 5 nm) acts as buffer layer to prevent charge recombination. The matched materials allow achievement of good performances of the cells, in terms of short circuit current and power conversion efficiency. UV-visible spectrophotometry, glancing incident X-rays diffraction and X-rays reflectivity techniques were used to characterize thin films before cell realization; sealed solar cells were tested under simulated solar irradiance at 1 Sun to determine functional properties. - Highlights: • Double layer cadmium stannate–TiO 2 transparent front contact by sputtering. • Very thin TiO 2 buffer layer for charge recombination prevention. • Application of novel transparent contact in standard dye sensitized solar cells

Adsorptive removal of cationic dye from aqueous solution using ...

African Journals Online (AJOL)

PROF HORSFALL

Received 15 October 2017, received in revised form 03 December 2017, accepted 31 December 2017. Keywords: African Border Tree, ... to remove dyes include flocculation, oxidation, ..... estuarine algae, crustaceans and fishes. Environ.

Fenton-Like Oxidation of Malachite Green Solutions: Kinetic and Thermodynamic Study

Directory of Open Access Journals (Sweden)

Saeedeh Hashemian

2013-01-01

Full Text Available Oxidation by Fenton-like (Fe3+/H2O2 reactions is proven to be an economically feasible process for destruction of a variety of hazardous pollutants in wastewater. In this study, the degradation and mineralization of malachite green dye are reported using Fenton-like reaction. The effects of different parameters like pH of the solution, the initial concentrations of Fe3+, H2O2, and dye, temperature, and added electrolytes (Cl− and on the oxidation of the dye were investigated. Optimized condition was determined. The efficiency of 95.5% degradation of MAG after 15 minutes of reaction at pH 3 was obtained. TOC removal indicates partial and insignificant mineralization of malachite green dye. The results of experiments showed that degradation of malachite green dye in Fenton-like oxidation process can be described with a pseudo-second-order kinetic model. The thermodynamic constants of the Fenton oxidation process were evaluated. The results implied that the oxidation process was feasible, spontaneous, and endothermic. The results will be useful for designing the treatment systems of various dye-containing wastewaters.

Gender differences in scalp hair growth rates are maintained but reduced in pattern hair loss compared to controls.

Science.gov (United States)

Van Neste, D J J; Rushton, D H

2016-08-01

Hair loss is related to follicular density, programmed regrowth and hair productivity. The dissatisfaction with hair growth in patients experiencing hair loss might be due to slower linear hair growth rate (LHGR). LHGR and hair diameter was evaluated in Caucasian controls and patients with patterned hair loss employing the validated non-invasive, contrast-enhanced-phototrichogram with exogen collection. We evaluated 59,765 anagen hairs (controls 24,609, patients 35,156) and found thinner hairs grew slower than thicker hairs. LHGR in normal women was generally higher than in normal men. LHGR correlates with hair diameter (P hair of equal thickness in controls, subjects affected with patterned hair loss showed reduced hair growth rates, an observation found in both male and female patients. Males with pattern hair loss showed further reduction in growth rates as clinical severity worsened. However, sample size limitations prevented statistical evaluation of LHGR in severely affected females. Caucasian ethnicity. In pattern hair loss, LHGR significantly contributes to the apparent decrease in hair volume in affected areas. In early onset, LHRG might have a prognostic value in females but not in males. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Peripheral Hole Acceptor Moieties on an Organic Dye Improve Dye‐Sensitized Solar Cell Performance

Science.gov (United States)

Hao, Yan; Gabrielsson, Erik; Lohse, Peter William; Yang, Wenxing; Johansson, Erik M. J.; Hagfeldt, Anders

2015-01-01

Investigation of charge transfer dynamics in dye‐sensitized solar cells is of fundamental interest and the control of these dynamics is a key factor for developing more efficient solar cell devices. One possibility for attenuating losses through recombination between injected electrons and oxidized dye molecules is to move the positive charge further away from the metal oxide surface. For this purpose, a metal‐free dye named E6 is developed, in which the chromophore core is tethered to two external triphenylamine (TPA) units. After photoinduced electron injection into TiO2, the remaining hole is rapidly transferred to a peripheral TPA unit. Electron–hole recombination is slowed down by 30% compared to a reference dye without peripheral TPA units. Furthermore, it is found that the added TPA moieties improve the electron blocking effect of the dye, retarding recombination of electrons from TiO2 to the cobalt‐based electrolyte. PMID:27722076

Help! It's Hair Loss!

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Hair Loss KidsHealth / For Kids / Hair Loss What's in this ... head are in the resting phase. What Causes Hair Loss? Men, especially older men, are the ones who ...

Skin, Hair, and Nails

Science.gov (United States)

... Safe Videos for Educators Search English Español Skin, Hair, and Nails KidsHealth / For Parents / Skin, Hair, and ... piel, el cabello y las uñas About Skin, Hair and Nails Skin is our largest organ. If ...

Strongly oxidizing perylene-3,4-dicarboximides for use in water oxidation photoelectrochemical cells

Energy Technology Data Exchange (ETDEWEB)

Lindquist, Rebecca J.; Phelan, Brian T.; Reynal, Anna; Margulies, Eric A.; Shoer, Leah E.; Durrant, James R.; Wasielewski, Michael R.

2016-01-01

Perylene-3,4-dicarboximide (PMI) based chromophores have demonstrated the ability to inject electrons into TiO2 for dye-sensitized solar cell applications and to accept electrons from metal complexes relevant to water oxidation, but they are nearly unexplored for use in photoelectrochemical cells (PECs) for solar fuels generation. A series of related PMIs with high oxidation potentials and carboxylate binding groups was synthesized and investigated for this purpose. Charge injection and recombination dynamics were measured using transient absorption (TA) spectroscopy on the picosecond to second timescales. The dynamics and electron injection yields were correlated with the PMI energetics and structures. Injection began in less than 1 ps for the dye with the best performance and a significant charge-separated state yield remained at long times. Finally, this chromophore was used to oxidize a covalently bound water oxidation precatalyst following electron injection into TiO2 to demonstrate the utility of the dyes for use in PECs.

Alignment of the dye's molecular levels with the TiO2 band edges in dye-sensitized solar cells: a DFT-TDDFT study

International Nuclear Information System (INIS)

De Angelis, Filippo; Fantacci, Simona; Selloni, Annabella

2008-01-01

We present a theoretical study of the lineup of the LUMO of Ru(II)-polypyridyl (N3 and N719) molecular dyes with the conduction band edge of a TiO 2 anatase nanoparticle. We use density functional theory (DFT) and the Car-Parrinello scheme for efficient optimization of the dye-nanoparticle systems, followed by hybrid B3LYP functional calculations of the electronic structure and time-dependent DFT (TDDFT) determination of the lowest vertical excitation energies. The electronic structure and TDDFT calculations are performed in water solution, using a continuum model. Various approximate procedures to compute the excited state oxidation potential of dye sensitizers are discussed. Our calculations show that the level alignment for the interacting nanoparticle-sensitizer system is very similar, within about 0.1 eV, to that for the separated TiO 2 and dye. The excellent agreement of our results with available experimental data indicates that the approach of this work could be used as an efficient predictive tool to help the optimization of dye-sensitized solar cells.

The amazing miniorgan: Hair follicle

Directory of Open Access Journals (Sweden)

Çiler Çelik Özenci

2014-06-01

Full Text Available Hair is a primary characteristic of mammals, and exerts a wide range of functions including thermoregulation, physical protection, sensory activity, and social interactions. The hair shaft consists of terminally differentiated keratinocytes that are produced by the hair follicle. Hair follicle development takes place during fetal skin development and relies on tightly regulated ectodermal–mesodermal interactions. Hair follicles form during embryonic development and, after birth, undergo recurrent cycling of growth (anagen, apoptosis-driven regression (catagen, and relative quiescence (telogen. As a functional mini-organ, the hair follicle develops in an environment with dynamic and alternating changes of diverse molecular signals. Our molecular understanding of hair follicle biology relies heavily on genetically engineered mouse models with abnormalities in hair structure, growth, and/or pigmentation and significant advances have been made toward the identification of key signaling pathways and the regulatory genes involved. In this review, the basic concepts of hair follicle, a mini-complex organ, biology will be presented and its importance in clinical applications will be summarized.

Amphetamines and cannabinoids testing in hair: Evaluation of results from a two-year period.

Science.gov (United States)

Burgueño, María José; Alonso, Amaya; Sánchez, Sergio

2016-08-01

This paper presents an overview of a set of amphetamines and cannabinoids tests performed on head hair samples from the Medico-Legal sector at the Madrid Department of the Spanish National Institute of Toxicology and Forensic Sciences during the years 2013 and 2014. The hair samples were tested for five stimulant phenylalkylamine derivatives -amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxy-amphetamine (MDA), and 3,4-methylenedioxy-N-ethylamphetamine (MDEA)- and/or two cannabinoids-Δ(9)-tetrahydrocannabinol (THC) and cannabinol (CBN)- by gas chromatography equipped with mass spectrometry detection in selected-ion monitoring mode, applying a method accredited to ISO/IEC 17025 standards. The test results were interpreted according to the confirmation cut-offs proposed by the Society of Hair Testing (SoHT) to identify chronic drug use. The ratios of positive results were studied in relation to gender, age, hair colour, dyeing and length of the tested samples to assess the independence from these variables or the association with them. Low, medium and high ranges of concentration were also estimated for each drug. 21.94% of the 2954 hair samples tested for phenylalkylamine derivatives were positive for one or more substances. 16.38% of the samples were positive for AP, 12.09% for MDMA and only 0.44% for MA. 6.60% of the tested samples were positive for AP/MDMA combination. A total of 3178 samples were tested for cannabinoids, resulting in 53.40% positive for THC and CBN. Simultaneous tests for phenylalkylamine derivatives and cannabinoids were performed in 2931 of the samples; 14.94% of them were positive for THC, CBN, and one or more amphetamines. According to the results from the statistical analysis, the use of THC and MDMA vary with age and gender among the Medico-Legal sector in an extended area of Spain, while the use of AP appears to be independent of these variables. On the other hand, the results of THC in

Supercritical water oxidation of colored smoke, dye, and pyrotechnic compositions. Final report: Pilot plant conceptual design

Energy Technology Data Exchange (ETDEWEB)

LaJeunesse, C.A.; Chan, Jennifer P.; Raber, T.N.; Macmillan, D.C.; Rice, S.F.; Tschritter, K.L.

1993-11-01

The existing demilitarization stockpile contains large quantities of colored smoke, spotting dye, and pyrotechnic munitions. For many years, these munitions have been stored in magazines at locations within the continental United States awaiting completion of the life-cycle. The open air burning of these munitions has been shown to produce toxic gases that are detrimental to human health and harmful to the environment. Prior efforts to incinerate these compositions have also produced toxic emissions and have been unsuccessful. Supercritical water oxidation (SCWO) is a rapidly developing hazardous waste treatment method that can be an alternative to incineration for many types of wastes. The primary advantage SCWO affords for the treatment of this selected set of obsolete munitions is that toxic gas and particulate emissions will not occur as part of the effluent stream. Sandia is currently designing a SCWO reactor for the US Army Armament Research, Development & Engineering Center (ARDEC) to destroy colored smoke, spotting dye, and pyrotechnic munitions. This report summarizes the design status of the ARDEC reactor. Process and equipment operation parameters, process flow equations or mass balances, and utility requirements for six wastes of interest are developed in this report. Two conceptual designs are also developed with all process and instrumentation detailed.

Zebrafish hair cell mechanics and physiology through the lens of noise-induced hair cell death

Science.gov (United States)

Coffin, Allison B.; Xu, Jie; Uribe, Phillip M.

2018-05-01

Hair cells are exquisitely sensitive to auditory stimuli, but also to damage from a variety of sources including noise trauma and ototoxic drugs. Mammals cannot regenerate cochlear hair cells, while non-mammalian vertebrates exhibit robust regenerative capacity. Our research group uses the lateral line system of larval zebrafish to explore the mechanisms underlying hair cell damage, identify protective therapies, and determine molecular drivers of innate regeneration. The lateral line system contains externally located sensory organs called neuromasts, each composed of ˜8-20 hair cells. Lateral line hair cells are homologous to vertebrate inner ear hair cells and share similar susceptibility to ototoxic damage. In the last decade, the lateral line has emerged as a powerful model system for understanding hair cell death mechanisms and for identifying novel protective compounds. Here we demonstrate that the lateral line is a tractable model for noise-induced hair cell death. We have developed a novel noise damage system capable of inducing over 50% loss of lateral line hair cells, with hair cell death occurring in a dose- and time-dependent manner. Cell death is greatest 72 hours post-exposure. However, early signs of hair cell damage, including changes in membrane integrity and reduced mechanotransduction, are apparent within hours of noise exposure. These features, early signs of damage followed by delayed hair cell death, are consistent with mammalian data, suggesting that noise acts similarly on zebrafish and mammalian hair cells. In our future work we will use our new model system to investigate noise damage events in real time, and to develop protective therapies for future translational research.

Essential of Hair Care Cosmetics

Directory of Open Access Journals (Sweden)

Aurora Alessandrini

2016-09-01

Full Text Available Nowadays, hair care and style play a very important role in people’s physical aspect and self-perception. Hair cosmetics can be distinguished into two main categories: cosmetics with temporary effect on the hair, for example shampoos, conditioners, sprays, and temporary colors; and cosmetics with permanent effect on the hair, such as permanent waves, relaxers, bleaches and permanent colors. These cosmetic procedures may induce hair abnormalities. We provide an overview on the most important characteristics of these procedures, analyzing components and effects on the hair. Finally, we evaluated new camouflage techniques and tattoo scalp.

Role of Dyestuff in Improving Dye-Sensitized Solar Cell Performance

Directory of Open Access Journals (Sweden)

Yehia Selim

2017-03-01

Full Text Available Dye-sensitized solar cells DSSCs have attracted great attention for their simple fabrication process, low production costs, relatively high conversion efficiency, and being environmental friendly.DSSC are a combination of materials, consisting of a transparent electrode coated with a dye-sensitized mesoporous film of nanocrystalline particles of TiO2, an electrolyte containing a suitable redox-couple and a electrode.DSSCs use organic dye assist to produce electricity in a wide range of light conditions, indoors and outdoors.The dye in the solar cell is the key element since it is responsible for light harvesting ability, photoelectron generation (the creation of free charges after injection of electrons into the nanostructured semi-conducting oxide and electron transfer.For this reason, this paper gives a background of dyestuff, types and limitations. The motivation of this work is to design a simple, easy and prepare an efficient organic dye sensitizer.Also, this paper investigates the important criteria which are considered for selecting dye to enhance DSSC efficiency. 

Interaction and photodegradation characteristics of fluorescein dye in presence of ZnO nanoparticles.

Science.gov (United States)

Bardhan, Munmun; Mandal, Gopa; Ganguly, Tapan

2011-04-01

The interaction between xanthene dye Fluorescein (Fl) and zinc oxide (ZnO) nanoparticles is investigated under physiological conditions. From the analysis of the steady state and time resolved spectroscopic studies in aqueous solution static mode is found to be responsible in the mechanism of fluorescence quenching of the dye Fl in presence of ZnO. ZnO nanoparticles are used as photocatalyst in order to degrade Fl dye. At pH 7, a maximum degradation efficiency of 44.4% of the dye has been achieved in presence of ZnO as a nanophotocatalyst and the photodegradation follows second-order kinetics.

Poly(3,4-ethylenedioxythiophene)/reduced graphene oxide composites as counter electrodes for high efficiency dye-sensitized solar cells

Science.gov (United States)

Ma, Jinfu; Yuan, Shenghua; Yang, Shaolin; Lu, Hui; Li, Yingtao

2018-05-01

A facile, low cost, easy-controllable method to prepare Poly(3,4-ethylenedioxythiophene) (PEDOT)/reduced graphene oxide (rGO) composites by electrochemical deposition onto fluorinated tin oxide (FTO) as counter electrodes (CEs) in high performance dye-sensitized solar cells (DSSCs) is reported. The electro-deposition process was accomplished by electro-polymerization of graphene oxide (GO)/PEDOT composites onto FTO substrates followed by electrochemical reduction of the GO component. Electrochemical measurements show that the I-/I3- catalytic activity of the as-prepared PEDOT/rGO CE is improved compared with that of the pure PEDOT and PEDOT/GO electrode. Through the analysis of photoelectric properties, the performance of the electrodes fabricated with different polymerization times are compared, and the optimal preparation condition is determined. The photoelectric conversion efficiency (PCE) of the DSSC assembled with PEDOT/rGO electrode reaches 7.79%, close to 8.33% of the cell with Platinum (Pt) electrode, and increases by 13.2% compared with 6.88% of the device with the PEDOT electrode.

Organic dyes removal using magnetically modified rye straw

Energy Technology Data Exchange (ETDEWEB)

Baldikova, Eva, E-mail: baldie@email.cz [Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Safarikova, Mirka [Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic); Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic)

2015-04-15

Rye straw, a very low-cost material, was employed as a biosorbent for two organic water-soluble dyes belonging to different dye classes, namely acridine orange (acridine group) and methyl green (triarylmethane group). The adsorption properties were tested for native and citric acid–NaOH modified rye straw, both in nonmagnetic and magnetic versions. The adsorption equilibrium was reached in 2 h and the adsorption isotherms data were analyzed using the Langmuir model. The highest values of maximum adsorption capacities were 208.3 mg/g for acridine orange and 384.6 mg/g for methyl green. - Highlights: • Rye derivatives can be considered as efficient adsorbents for organic dyes. • Magnetic modification of straw by microwave-synthesized magnetic iron oxides. • Citric acid–NaOH modification increased the maximum adsorption capacities.

Advanced hair damage model from ultra-violet radiation in the presence of copper.

Science.gov (United States)

Marsh, J M; Davis, M G; Flagler, M J; Sun, Y; Chaudhary, T; Mamak, M; McComb, D W; Williams, R E A; Greis, K D; Rubio, L; Coderch, L

2015-10-01

Damage to hair from UV exposure has been well reported in the literature and is known to be a highly complex process involving initiation via absorption of UV light followed by formation and propagation of reactive oxygen species (ROS). The objective of this work was to understand these mechanisms, explain the role of copper in accelerating the formation of ROS and identify strategies to reduce the hair damage caused by these reactive species. The location of copper in hair was measured by Transmission electron microscopy-(TEM) X-ray energy dispersive spectroscopy (XEDS) and levels measured by ICP-OES. Protein changes were measured as total protein loss via the Lowry assay, and MALDI ToF was used to identify the biomarker protein fragments. TBARS assay was used to measure lipid peroxide formation. Sensory methods and dry combing friction were used to measure hair damage due to copper and UV exposure and to demonstrate the efficacy of N,N' ethylenediamine disuccinic acid (EDDS) and histidine chelants to reduce this damage. In this work, a biomarker protein fragment formed during UV exposure is identified using mass spectrometry. This fragment originates from the calcium-binding protein S100A3. Also shown is the accelerated formation of this peptide fragment in hair containing low levels of copper absorbed from hair during washing with tap water containing copper ions. Transmission electron microscopy (TEM) X-ray energy dispersive spectroscopy (XEDS) studies indicate copper is located in the sulphur-poor endo-cuticle region, a region where the S100A3 protein is concentrated. A mechanism for formation of this peptide fragment is proposed in addition to the possible role of lipids in UV oxidation. A shampoo and conditioner containing chelants (EDDS in shampoo and histidine in conditioner) is shown to reduce copper uptake from tap water and reduce protein loss and formation of S100A3 protein fragment. In addition, the long-term consequences of UV oxidation and

Electrochemical pulsed deposition of platinum nanoparticles on indium tin oxide/polyethylene terephthalate as a flexible counter electrode for dye-sensitized solar cells

International Nuclear Information System (INIS)

Wei, Yu-Hsuan; Chen, Chih-Sheng; Ma, Chen-Chi M.; Tsai, Chuen-Horng; Hsieh, Chien-Kuo

2014-01-01

In this study, a pulsed-mode electrochemical deposition (Pulse-ECD) technique was employed to deposit platinum nanoparticles (PtNPs) on the indium tin oxide/polyethylene terephthalate (ITO/PET) substrate as a flexible counter electrode for dye-sensitized solar cells (DSSCs). The characteristic properties of the Pulse-ECD PtNPs were prepared and compared to the traditional (electron beam) Pt film. The surface morphologies of the PtNPs were examined by field emission scanning electron microscopy (FE-SEM) and the atomic force microscope (AFM). The FE-SEM results showed that our PtNPs were deposited uniformly on the ITO/PET flexible substrates via the Pulse-ECD technique. The AFM results indicated that the surface roughness of the pulsed PtNPs influenced the power conversion efficiency (PCE) of DSSCs, due to the high specific surface area of PtNPs which enhanced the catalytic activities for the reduction (I 3 − to I − ) of redox electrolyte. In combination with a N719 dye-sensitized TiO 2 working electrode and an iodine-based electrolyte, the DSSCs with the PtNPs flexible counter electrode showed a PCE of 4.3% under the illumination of AM 1.5 (100 mW cm −2 ). The results demonstrated that the Pulse-ECD PtNPs are good candidate for flexible DSSCs. - Highlights: • We used indium tin oxide/polyethylene terephthalate as a flexible substrate. • We utilized pulse electrochemical deposition to deposit platinum nanoparticles. • We synthesized a flexible counter electrode for dye-sensitized solar cell (DSSC). • The power conversion efficiency of DSSC was measured to be 4.3%

Biosorption and biodegradation of a sulfur dye in high-strength dyeing wastewater by Acidithiobacillus thiooxidans.

Science.gov (United States)

Nguyen, Thai Anh; Fu, Chun-Chieh; Juang, Ruey-Shin

2016-11-01

The ability of the bacterial strain Acidithiobacillus thiooxidans to remove sulfur blue 15 (SB15) dye from water samples was examined. This bacterium could not only oxidize sulfur compounds to sulfuric acid but also promote the attachment of the cells to the surface of sulfidic particles, therefore serving as an efficient biosorbent. The biosorption isotherms were better described by the Langmuir equation than by the Freundlich or Dubinin-Radushkevich equation. Also, the biosorption process followed the pseudo-second-order kinetics. At pH 8.3 and SB15 concentrations up to 2000 mg L(-1) in the biomass/mineral salt solution, the dye removal and decolorization were 87.5% and 91.4%, respectively, following the biosorption process. Biodegradation was proposed as a subsequent process for the remaining dye (250-350 mg L(-1)). A central composite design was used to analyze independent variables in the response surface methodology study. Under the optimal conditions (i.e., initial dye concentration of 300 mg L(-1), initial biomass concentration of 1.0 g L(-1), initial pH of 11.7, and yeast extract dose of 60 mg L(-1)), up to 50% of SB15 was removed after 4 days of biodegradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Octane-Assisted Reverse Micellar Dyeing of Cotton with Reactive Dyes

Directory of Open Access Journals (Sweden)

Alan Yiu-lun Tang

2017-12-01

Full Text Available In this study, we investigated the computer colour matching (CCM of cotton fabrics dyed with reactive dye using the octane-assisted reverse micellar approach. The aim of this study is to evaluate the colour quality and compare the accuracy between CCM forecasting and simulated dyeing produced by conventional water-based dyeing and octane-assisted reverse micellar dyeing. First, the calibration of dyeing databases for both dyeing methods was established. Standard samples were dyed with known dye concentrations. Computer colour matching was conducted by using the colour difference formula of International Commission on Illumination (CIE L*a*b*. Experimental results revealed that the predicted concentrations were nearly the same as the expected known concentrations for both dyeing methods. This indicates that octane-assisted reverse micellar dyeing system can achieve colour matching as good as the conventional water-based dyeing system. In addition, when comparing the colour produced by the conventional water-based dyeing system and the octane-assisted reverse micellar dyeing system, the colour difference (ΔE is ≤1, which indicates that the reverse micellar dyeing system could be applied for industrial dyeing with CCM.

Preparation and Performance of TiO2-ZnO/CNT Hetero-Nanostructures Applied to Photodegradation of Organic Dye

OpenAIRE

Da Dalt,Silvana; Alves,Annelise Kopp; Bergmann,Carlos Pérez

2016-01-01

Water pollution by organic compounds is one of the major challenges faced by industries that use dyeing processes. Thus, some methods were developed for degrading dyes in wastewaters, including heterogeneous photocatalysis by semiconductor oxides. However, these oxides have limited photocatalytic activity due to the fast recombination of photogenerated electron-hole pairs. The aim of this study is the use of a carbon nanotube (CNT) and TiO2-ZnO oxide junction from modified sol-gel method to p...

A dye-decolorizing peroxidase from Bacillus subtilis exhibiting substrate-dependent optimum temperature for dyes and β-ether lignin dimer

Science.gov (United States)

Min, Kyoungseon; Gong, Gyeongtaek; Woo, Han Min; Kim, Yunje; Um, Youngsoon

2015-01-01

In the biorefinery using lignocellulosic biomass as feedstock, pretreatment to breakdown or loosen lignin is important step and various approaches have been conducted. For biological pretreatment, we screened Bacillus subtilis KCTC2023 as a potential lignin-degrading bacterium based on veratryl alcohol (VA) oxidation test and the putative heme-containing dye-decolorizing peroxidase was found in the genome of B. subtilis KCTC2023. The peroxidase from B. subtilis KCTC2023 (BsDyP) was capable of oxidizing various substrates and atypically exhibits substrate-dependent optimum temperature: 30°C for dyes (Reactive Blue19 and Reactive Black5) and 50°C for high redox potential substrates (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid [ABTS], VA, and veratryl glycerol-β-guaiacyl ether [VGE]) over +1.0 V vs. normal hydrogen electrode. At 50°C, optimum temperature for high redox potential substrates, BsDyP not only showed the highest VA oxidation activity (0.13 Umg−1) among the previously reported bacterial peroxidases but also successfully achieved VGE decomposition by cleaving Cα-Cβ bond in the absence of any oxidative mediator with a specific activity of 0.086 Umg−1 and a conversion rate of 53.5%. Based on our results, BsDyP was identified as the first bacterial peroxidase capable of oxidizing high redox potential lignin-related model compounds, especially VGE, revealing a previously unknown versatility of lignin degrading biocatalyst in nature. PMID:25650125

Hair straightener poisoning

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002706.htm Hair straightener poisoning To use the sharing features on this page, please enable JavaScript. Hair straightener poisoning occurs when someone swallows products that ...

Hair spray poisoning

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002705.htm Hair spray poisoning To use the sharing features on this page, please enable JavaScript. Hair spray poisoning occurs when someone breathes in (inhales) ...

Dyeing of Polyester with Disperse Dyes: Part 2. Synthesis and Dyeing Characteristics of Some Azo Disperse Dyes for Polyester Fabrics

Directory of Open Access Journals (Sweden)

Alya M. Al-Etaibi

2016-06-01

Full Text Available The goal of this study was to utilize carrier for accelerating the rate of dyeing not only to enhance dyeing of polyester fabrics dyed with disperse dyes 3a,b, but also to save energy. Both the color strength expressed as dye uptake and the fastness properties of the dyed fabrics were evaluated.

Anaphylaxis, contact urticaria, and allergic asthma caused by persulfates in hair bleaching products

NARCIS (Netherlands)

Hoekstra, Miriam; Schuttelaar, M.L.; Coenraads, P.J.

2010-01-01

Background: Persulfate salts are potent oxidizing agents in hair bleach products that accelerate the bleaching process. Ammonium and potassium persulfates may cause delayedtype and immediate skin reactions. Also allergic asthma and rhinitis have been described. Objectives: Ammonium and potassium

Practical experiences in application of hair fatty acid ethyl esters and ethyl glucuronide for detection of chronic alcohol abuse in forensic cases.

Science.gov (United States)

Suesse, S; Pragst, F; Mieczkowski, T; Selavka, C M; Elian, A; Sachs, H; Hastedt, M; Rothe, M; Campbell, J

2012-05-10

This article presents results from 1872 hair samples, which were analyzed for fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG). The results were evaluated in the context of self-reported drinking behavior, the use of hair cosmetics, the gender of the sample donors and hair sample length. For comparison, CDT and GGT in serum were available in 477 and 454 cases, respectively. A number of alcohol abstainers or low moderate drinkers and excessive drinkers were selected for assessment of cut-offs for FAEEs in the proximal 6cm hair segments and for EtG in the proximal 3cm hair segments. Cut-off values were assessed by ROC analysis. It was found that the cut-offs of 1.0ng/mg FAEE and 30pg/mg EtG presently used for excessive drinking lead to a low portion of false positives (4% and 3% respectively) but to a higher portion of false negatives (23% and 25% respectively). Comparison of the mean and medium concentrations in samples without any reported hair cosmetics (N=1079) and in samples with reported use of hair spray (N=79) showed an increase by the factor of about two for FAEE but no significant difference for EtG. Mean values of EtG were decreased by 80% in bleached samples (N=164) and by 63% in dyed samples (N=96). There was no significant effect of bleaching and dyeing on FAEE. Hair gel and hair wax, oil or grease showed no significant effect on both FAEE and EtG. With respect to gender and investigated hair length ambiguous results were obtained because of major differences in the compared subpopulations of male with higher alcohol consumption and mainly shorter hair, and less drinking female with longer hair. For excessive drinkers FAEEs in the 0-6cm hair segment and EtG in the 0-3cm segment decreased with increasing time of reported abstinence before sample collection. These drinkers attain the level of teetotalers only after more than 10 months of abstinence. In comparison to scalp hair, FAEEs recovered from armpit hair and leg hair were lower and from

Diseases that turn African hair silky.

Science.gov (United States)

Ajose, Frances O A

2012-11-01

African hair in its natural state poses tenacious grooming challenges; consequently a large portion of the African cosmetic industry is focused on means to relax the tight curls of African hair to make the hair more manageable. In malnourished and hypoproteinemic states, African hair straightens in an uncomplimentary manner. Recently, we observed that in certain diseases African hair changes to a desirable silky wavy texture. To identify the diseases that turn African hair silky and their parameters we examined 5612 dermatology patients at a tertiary hospital in Nigeria. We then studied the clinical and basic laboratory parameters of those patients whose diseases were accompanied by the silky hair change. Silky hair change similar to the hair of the African neonatal child was observed in five diseases, namely AIDS, rheumatoid arthritis, systemic lupus erythematosus, pulmonary tuberculosis with cachexia, and Behçet's disease. Our study identified retrogression of African hair to the neonatal structure in five diseases. Anemia of chronic illness, high erythrocyte sedimentation rate, and mild hypocalcemia were significant laboratory parameters. This is an important observation, which should excite and advance research into the nature and structure of African hair. The causes of structural hair changes should include these five diseases. © 2012 The International Society of Dermatology.

Improved radiocarbon analyses of modern human hair to determine the year-of-death by cross-flow nanofiltered amino acids: common contaminants, implications for isotopic analysis, and recommendations.

Science.gov (United States)

Santos, Guaciara M; De La Torre, Hector A Martinez; Boudin, Mathieu; Bonafini, Marco; Saverwyns, Steven

2015-10-15

In forensic investigation, radiocarbon ((14)C) measurements of human tissues (i.e., nails and hair) can help determine the year-of-death. However, the frequent use of cosmetics can bias hair (14)C results as well as stable isotope values. Evidence shows that hair exogenous impurities percolate beyond the cuticle layer, and therefore conventional pretreatments are ineffective in removing them. We conducted isotopic analysis ((14)C, δ(13)C, δ(15)N and C/N) of conventionally treated and cross-flow nanofiltered amino acid (CFNAA)-treated samples (scalp- and body-hair) from a single female subject using fingernails as a reference. The subject studied frequently applies a permanent dark-brown dye kit to her scalp-hair and uses other care products for daily cleansing. We also performed pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analyses of CFNAA-treated scalp-hair to identify contaminant remnants that could possibly interfere with isotopic analyses. The conventionally treated scalp- and body-hair showed (14)C offsets of ~21‰ and ~9‰, respectively. These offsets confirm the contamination by petrochemicals in modern human hair. A single CFNAA extraction reduced those offsets by ~34%. No significant improvement was observed when sequential extractions were performed, as it appears that the procedure introduced some foreign contaminants. A chromatogram of the CFNAA scalp-hair pyrolysis products showed the presence of petroleum and plant/animal compound residues, which can bias isotopic analyses. We have demonstrated that CFNAA extractions can partially remove cosmetic contaminants embedded in human hair. We conclude that fingernails are still the best source of keratin protein for year-of-death determinations and isotopic analysis, with body-hair and/or scalp-hair coupled with CFNAA extraction a close second. Copyright © 2015 John Wiley & Sons, Ltd.

Nano-dyeing

Directory of Open Access Journals (Sweden)

Ning Cui-Juan

2016-01-01

Full Text Available Dyeing nanofibers is a frontier of both modern textile engineering and nanotechnology. This paper suggest a feasible method for dyeing nanofibers with a natural red (Roselle Calyx by bubble electrospinning. Reactive dye (Red S3B and acid dye (Red 2B were also used in the experiment for comparison. The dyeing process was finished during the spinning process.

Synthesis of Metal-Oxide/Carbon-Fiber Heterostructures and Their Properties for Organic Dye Removal and High-Temperature CO2 Adsorption

Science.gov (United States)

Shao, Liangzhi; Nie, Shibin; Shao, Xiankun; Zhang, LinLin; Li, Benxia

2018-03-01

One-dimensional metal-oxide/carbon-fiber (MO/CF) heterostructures were prepared by a facile two-step method using the natural cotton as a carbon source the low-cost commercial metal salts as precursors. The metal oxide nanostructures were first grown on the cotton fibers by a solution chemical deposition, and the metal-oxide/cotton heterostructures were then calcined and carbonized in nitrogen atmosphere. Three typical MO/CF heterostructures of TiO2/CF, ZnO/CF, and Fe2O3/CF were prepared and characterized. The loading amount of the metal oxide nanostructures on carbon fibers can be tuned by controlling the concentration of metal salt in the chemical deposition process. Finally, the performance of the as-obtained MO/CF heterostructures for organic dye removal from water was tested by the photocatalytic degradation under a simulated sunlight, and their properties of high-temperature CO2 adsorption were predicted by the temperature programmed desorption. The present study would provide a desirable strategy for the synthesis of MO/CF heterostructures for various applications.

Systemic causes of hair loss.

Science.gov (United States)

Lin, Richard L; Garibyan, Lilit; Kimball, Alexandra B; Drake, Lynn A

2016-09-01

Hair loss is both a common chief complaint by patients and a clinical challenge for physicians, especially general practitioners, yet few dermatological problems yield as much patient satisfaction when resolved as hair loss. The diagnosis is often attributed to androgen-related hair loss, while other causes, some of which are life-threatening but treatable, are overlooked. We searched for relevant literature on hair loss and supported these findings with our clinical experience to identify seven major systemic etiologies of hair loss, ranging from infectious agents to consumption of unsafe supplements. Many causes are only described in the literature through case studies, though some original articles and meta-analyses are available. Careful history taking, proper examination techniques, and judicious use of laboratory tests are essential to reach at the correct diagnosis in a cost-effective manner when performing patient work-up. Such methodical evaluation of hair loss can result in the appropriate treatment plan and provide significant patient satisfaction. Key messages Hair loss is a common chief complaint and a difficult challenge for both general practitioners and dermatology consultants. We identified seven major categories of systemic hair loss etiology and present a framework for their clinical evaluation. A methodical approach to hair loss can result in the appropriate treatment plan and provide significant patient satisfaction.

Electrodeposition of zinc oxide/tetrasulfonated copper phthalocyanine hybrid thin film for dye-sensitized solar cell application

International Nuclear Information System (INIS)

Luo Xinze; Xu Lin; Xu Bingbing; Li Fengyan

2011-01-01

Hybrid film of zinc oxide (ZnO) and tetrasulfonated copper phthalocyanine (TSPcCu) was grown on an indium tin oxide (ITO) glass by one-step cathodic electrodeposition from aqueous mixtures of Zn(NO 3 ) 2 , TSPcCu and KCl. The addition of TSPcCu strongly influences the morphology and crystallographic orientation of the ZnO. The nanosheets stack of ZnO leads to a porous surface structure which is advantageous to further adsorb organic dyes. The photovoltaic properties were investigated by assembling the DSSC device based on both the only ZnO film and the ZnO/TSPcCu hybrid films. Photoelectrochemical analysis revealed that the optimized DSSC device with TSPcCu represented a more than three-fold improvement in power conversion efficiency than the device without TSPcCu. The DSSC based on ZnO/TSPcCu hybrid films demonstrates an open circuit voltage of 0.308 V, a short circuit current of 90 μA cm -2 , a fill factor of 0.26, and a power conversion efficiency of 0.14%.

Electrodeposition of zinc oxide/tetrasulfonated copper phthalocyanine hybrid thin film for dye-sensitized solar cell application

Energy Technology Data Exchange (ETDEWEB)

Luo Xinze [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China); College of Chemistry and Biological Science, Yili Normal University, Yining 835000, (China); Xu Lin, E-mail: linxu@nenu.edu.cn [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China); Xu Bingbing; Li Fengyan [Key Laboratory of Polyoxometalates Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China)

2011-05-15

Hybrid film of zinc oxide (ZnO) and tetrasulfonated copper phthalocyanine (TSPcCu) was grown on an indium tin oxide (ITO) glass by one-step cathodic electrodeposition from aqueous mixtures of Zn(NO{sub 3}){sub 2}, TSPcCu and KCl. The addition of TSPcCu strongly influences the morphology and crystallographic orientation of the ZnO. The nanosheets stack of ZnO leads to a porous surface structure which is advantageous to further adsorb organic dyes. The photovoltaic properties were investigated by assembling the DSSC device based on both the only ZnO film and the ZnO/TSPcCu hybrid films. Photoelectrochemical analysis revealed that the optimized DSSC device with TSPcCu represented a more than three-fold improvement in power conversion efficiency than the device without TSPcCu. The DSSC based on ZnO/TSPcCu hybrid films demonstrates an open circuit voltage of 0.308 V, a short circuit current of 90 {mu}A cm{sup -2}, a fill factor of 0.26, and a power conversion efficiency of 0.14%.

Managing hair loss in midlife women.

Science.gov (United States)

Mirmirani, Paradi

2013-02-01

Hair is considered one of the most defining aspects of human appearance. Hair loss, or alopecia in women is often met with significant emotional distress and anxiety. In midlife, women may encounter various hormonal and age-related physiologic changes that can lead to alterations in hair texture and growth. The most significant hormonal alteration is the onset of menopause in which there is a cessation of ovarian estrogen production. This decrease in estrogen is known to have deleterious effects on the skin and cutaneous appendages. As our understanding of the molecular and hormonal controls on the hair follicle has grown, there has been increased interest in the various modulators of hair growth, including the potential role of estrogen. Further study of hair changes in midlife women provides an important opportunity for identification of the complex regulation of hair growth as well as identification of treatment targets that may specifically benefit women. In this review, management of hair loss in midlife women is discussed with a focus on three most commonly encountered clinical conditions: female pattern hair loss, hair shaft alterations due to hair care, and telogen effluvium. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Hair-on-hair static friction coefficient can be determined by tying a knot.

Science.gov (United States)

Chevalier, Nicolas R

2017-11-01

Characterizing the tribological properties of the hair-hair interface is important to quantify the manageability of hair and to assess the performance of hair care products. Audoly et al. (Phys. Rev. Lett. 99, 164301, 2007) derived an equation relating the self-friction coefficient of an elastic fiber to the dimensions of a simple, relaxed overhand knot made from this fiber. I experimentally tested and validated their equation using nylon thread and an independent measurement of its self-friction coefficient. I show that this methodology can be applied to provide high-throughput data on the static self-friction coefficient of single hair fibers in various conditions and to quantitatively assess how hair care treatments (conditioner, relaxant) alter frictional properties. I find that treatment of hair with 1M sodium hydroxide leads to a quick, irreversible self-friction coefficient increase; the resulting fine frictional fibers can be used to form very small knots for microsurgical vessel and organ ligature in medicine or embryology. The relaxed overhand knot method can more generally be used to measure the self-friction coefficients of a wide range of elastic fibers from the nano- (e.g. proteins, nanotubes) to the macro-scale (e.g. textile fiber, fiberglass). Copyright © 2017 Elsevier B.V. All rights reserved.

Effective extraction and simultaneous determination of Sudan dyes from tomato sauce and chili-containing foods using magnetite/reduced graphene oxide nanoparticles coupled with high-performance liquid chromatography.

Science.gov (United States)

Zhang, Ming-Yue; Wang, Man-Man; Hao, Yu-Lan; Shi, Xin-Ran; Wang, Xue-Sheng

2016-05-01

A simple, effective, and robust magnetic solid-phase extraction method was developed using magnetite/reduced graphene oxide nanoparticles as the adsorbent for the simultaneous determination of Sudan dyes (I, II, III, and IV) in foodstuffs. The magnetite/reduced graphene oxide nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. The extraction parameters including extraction time, elution solution, and elution time and volume were investigated in detail. Such magnetite/reduced graphene oxide nanoparticles based magnetic solid-phase extraction in combination with high-performance liquid chromatography and variable wavelength detection gave the detection limits of 3-6 μg/kg for Sudan I-IV in chili sauce, tomato sauce, chili powder, and chili flake samples. The recoveries were 79.6-108% at three spiked levels with the intra- and inter-day relative standard deviations of 1.2-8.6 and 4.5-9.6%, respectively. The feasibility was further performed by a comparison with commercial alumina-N. This method is suitable for the routine analysis of Sudan dyes due to its sensitivity, simplicity, and low cost. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoelectrochemical studies of dye-sensitized solar cells using organic dyes

Energy Technology Data Exchange (ETDEWEB)

Marinado, Tannia

2009-10-15

The dye-sensitized solar cell (DSC) is a promising efficient low-cost molecular photovoltaic device. One of the key components in DSCs is the dye, as it is responsible for the capture of sunlight. State-of-the-art DSC devices, based on ruthenium dyes, show record efficiencies of 10-12 %. During the last decade, metal-free organic dyes have been extensively explored as sensitizers for DSC application. The use of organic dyes is particularly attractive as it enables easy structural modifications, due to fairly short synthetic routes and reduced material cost. Novel dye should in addition to the light-harvesting properties also be compatible with the DSC components. In this thesis, a series of new organic dyes are investigated, both when integrated in the DSC device and as individual components. The evaluation methods consisted of different electrochemical and photoelectrochemical techniques. Whereas the light-harvesting properties of the dyes were fairly easily improved, the behavior of the dye integrated in the DSC showed less predictable photovoltaic results. The dye series studied in Papers II and IV revealed that their dye energetics limited vital electron-transfer processes, the dye regeneration (Paper II) and injection quantum yield (Paper IV). Further, in Papers III-VI, it was observed that different dye structures seemed to alter the interfacial electron recombination with the electrolyte. In addition to the dye structure sterics, some organic dyes appear to enhance the interfacial recombination, possibly due to specific dye-redox acceptor interaction (Paper V). The impact of dye sterical modifications versus the use of coadsorbent was explored in Paper VI. The dye layer properties in the presence and absence of various coadsorbents were further investigated in Paper VII. The core of this thesis is the identification of the processes and properties limiting the performance of the DSC device, aiming at an overall understanding of the compatibility between the

Black Hole's 1/N Hair

CERN Document Server

Dvali, Gia

2013-01-01

According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an inverse mass-square effect. Such hair is predicted in the microscopic quantum description in which a black hole represents a self-sustained leaky Bose-condensate of N soft gravitons. In this picture the Hawking radiation is the quantum depletion of the condensate. Within this picture we show that quantum black hole physics is fully compatible with continuous global symmetries and that global hair appears with the strength B/N, where B is the global charge swallowed by the black hole. For large charge this hair has dramatic effect on black hole dynamics. Our findings can have interesting astrophysical consequences, such as existence of black holes with large detectable baryonic and leptonic numbers.

Grey Hair Evlsion Technique For Evaluating the Effect of Drugs For the Treatment of Premature Grey Hairs

Directory of Open Access Journals (Sweden)

J S Pasricha

1985-01-01

Full Text Available An improved method for evaluating the effect of treatment for premature grey hairs is described. The method consists of pulling out all the grey hairs in a patient and counting the number removed. Simultaneously, the converted hairs are also snipped at the grey-black junction and counted. After a gap of 3 months, the survey is repeated to count the number of hairs which have regrowing as grey hairs, the hairs which have become grey and also the hairs which have got converted into black during this period. Such surveys are repeated at 3 months intervals over a period of several years to see the progress of greying of hair in an individual and to evaluate the effect of various therapeutic procedures.

A panchromatic anthracene-fused porphyrin sensitizer for dye-sensitized solar cells

KAUST Repository

Ball, James M.

2012-01-01

The development of ruthenium-free sensitizers which absorb light over a broad range of the solar spectrum is important for improving the power conversion efficiency of dye-sensitized solar cells. Here we study three chemically tailored porphyrin-based dyes. We show that by fusing the porphyrin core to an anthracene unit, we can extend the conjugation length and lower the optical gap, shifting the absorption spectrum into the near-infrared (NIR). All three dyes were tested in dye-sensitized solar cells, using both titanium dioxide and tin dioxide as the electron-transport material. Solar cells incorporating the anthracene-fused porphyrin dye exhibit photocurrent collection at wavelengths up to about 1100 nm, which is the longest reported for a porphyrin-based system. Despite extending the photon absorption bandwidth, device efficiency is found to be low, which is a common property of cells based on porphyrin dyes with NIR absorption. We show that in the present case the efficiency is reduced by inefficient electron injection into the oxide, as opposed to dye regeneration, and highlight some important design considerations for panchromatic sensitizers. © 2012 The Royal Society of Chemistry.

Photodynamic therapy for hair removal

Directory of Open Access Journals (Sweden)

Mohamed H. M. Ali

2013-05-01

Full Text Available Background: Unwanted hair is one of the most common medical problems affecting women of reproductive age inducing a lot of psychological stress and threatening their femininity and self-esteem. Old methods of removing unwanted hair include shaving, waxing, chemical depilation, and electrolysis, all of which have temporary results. However laser-assisted hair removal is the most efficient method of long-term hair removal currently available. It is desirable to develop a reduced cost photodynamic therapy (PDT system whose properties should include high efficiency and low side-effects. Method: Mice skin tissues were used in this study and divided into six groups such as controls, free methylene blue (MB incubation, liposome methylene blue (MB incubation, laser without methylene blue (MB, free methylene blue (MB for 3 and 4 hrs and laser, liposome methylene blue (MB for 3 hrs and laser. Methylene blue (MBwas applied to wax epilated areas. The areas were irradiated with CW He-Ne laser system that emits orange-red light with wavelength 632.8 nm and 10 mW at energy density of 5 J/ cm2 for 10 minutes. The UV-visible absorption spectrum was collected by Cary spectrophotometer. Results: Methylene blue (MB is selectively absorbed by actively growing hair follicles due to its cationic property. Methylene blue (MBuntreated sections showed that hair follicle and sebaceous gland are intact and there is no change due to the laser exposure. Free methylene blue (MB sections incubated for 3 hrs showed that He:Ne laser induced destruction in hair follicles, leaving an intact epidermis. Treated section with free methylene blue (MB for 4 hrs showed degeneration and necrosis in hair follicle, leaving an intact epidermis. Liposomal methylene blue (MB sections incubated for 3 hrs showed He:Ne laser induced destruction in hair follicles with intradermal leucocytic infiltration. Conclusions: Low power CW He:Ne laser and methylene blue (MB offered a successful PDT system

Optimization of degration Basic blue 47 dye Without the use of oxidizing agents by ultrasound-electrochemical techniques and central composite design ( CCD

Directory of Open Access Journals (Sweden)

atefeh sadat rezaei tousi

2017-07-01

Full Text Available Intruoduction: One of the most important environmental pollutant is dye compounds. Accordingly, numerous methods have already been proposed for removing these pollutants from industrial waste especially the textile industry. One of the methods that has received a great deal of attention in recent years sono-electrochemical method. Methods: This experimental study was conducted in a batch laboratory scale. In this approach, using the Central Composite Design (CCD statistical method, the interactive effects of four important variables of pH, the dye solution concentration, decolorization time, and potential were analyzed and investigated. Results: Based on the conducted experiments and the results obtained in the absence of the hydrogen peroxide oxidant agent, the best conditions for decolorization in the optimal conditions of pH=9, dye concentration=303.3 μM, contact time of 93 min, and a potential of 0.81 V corresponding to the design by the software was 92.8% which was obtained experimentally as 92.34% . Chemical Oxygen Demand (COD removal was mention according optimized conditions by the combination of ultrasound-electrochemical process 96%  in this study. Conclusion: CCD was used as an effective method to measuring the concurrent effect of some important variables on BB47 dye removal. Based on the gained model. Accordingly, the optimal conditions (pH=9, dye concentration of 303/3μM, contact time of 93 min, and a potential of 0/81 V were determined by the software. The predicted decolorization percentage by the model was 92/8%  in these conditions, where it was obtained as 92/34 % after the experimental test. The closeness of these responses are indicative of appropriacy of the model.

KINETIC BEHAVIOR OF SOME AZO DYES DECOLORIZATION BY VARIATION OF ZINC OXIDE AND TITANIUM DIOXIDE CONCENTRATIONS

Directory of Open Access Journals (Sweden)

Wallace J. C. da Silva

Full Text Available The decolorization of three monoazo dyes (acid orange 7, direct orange 34, and methyl orange, one diazo dye (direct yellow 86 and one tetraazo dye (direct red 80 were mediated by n-type semiconductors as ZnO and TiO2 under pseudo-first order conditions at 30 ºC. The decolorization rate constants of these azo dyes were determined, varying the semiconductor concentration for the majority of them from 1.0 to 10.0 g L-1. In general, the highest rate constants were displayed for ZnO. This work elucidates that the decolorization capacity depends on the charge, structure, and adsorption of the azo dye on the semiconductor surface as well as the agglomeration of the photocatalyst particles.

Automatic hair detection in the wild

DEFF Research Database (Denmark)

Julian, Pauline; Dehais, Christophe; Lauze, Francois Bernard

2010-01-01

This paper presents an algorithm for segmenting the hair region in uncontrolled, real life conditions images. Our method is based on a simple statistical hair shape model representing the upper hair part. We detect this region by minimizing an energy which uses active shape and active contour....... The upper hair region then allows us to learn the hair appearance parameters (color and texture) for the image considered. Finally, those parameters drive a pixel-wise segmentation technique that yields the desired (complete) hair region. We demonstrate the applicability of our method on several real images....

Impacts of operating parameters on oxidation-reduction potential and pretreatment efficacy in the pretreatment of printing and dyeing wastewater by Fenton process

Energy Technology Data Exchange (ETDEWEB)

Wu, Huifang, E-mail: whfkhl@sina.com [College of Environment, Jiangsu Key Laboratory of Industrial Water-Conservation and Emission Reduction, Nanjing University of Technology, Nanjing 210009 (China); Wang, Shihe [Department of Municipal Engineering, Southeast University, Nanjing 210096 (China)

2012-12-15

Highlights: Black-Right-Pointing-Pointer A real printing and dyeing wastewater was pretreated by Fenton process. Black-Right-Pointing-Pointer We investigated impacts of operating parameters on ORP and pretreatment efficacy. Black-Right-Pointing-Pointer Relationship among ORP, operating parameters and treatment efficacy was established. Black-Right-Pointing-Pointer Pretreatment efficacy was in proportion to the exponent of temperature reciprocal. Black-Right-Pointing-Pointer We investigated kinetics of color and COD removal and BOD{sub 5}/COD ratio in solution. - Abstract: An experiment was conducted in a batch reactor for a real printing and dyeing wastewater pretreatment using Fenton process in this study. The results showed that original pH, hydrogen peroxide concentration and ferrous sulfate concentration affected ORP value and pretreatment efficacy greatly. Under experimental conditions, the optimal original pH was 6.61, and the optimal hydrogen peroxide and ferrous sulfate concentrations were 1.50 and 0.75 g L{sup -1}, respectively. The relationship among ORP, original pH, hydrogen peroxide concentration, ferrous sulfate concentration, and color (COD or BOD{sub 5}/COD) was established, which would be instructive in on-line monitoring and control of Fenton process using ORP. In addition, the effects of wastewater temperature and oxidation time on pretreatment efficacy were also investigated. With an increase of temperature, color and COD removal efficiencies and BOD{sub 5}/COD ratio increased, and they were in proportion to the exponent of temperature reciprocal. Similarly, color and COD removal efficiencies increased with increasing oxidation time, and both color and COD removal obeyed the first-order kinetics. The BOD{sub 5}/COD ratio could be expressed by a second-degree polynomial with respect to oxidation time, and the best biodegradability of wastewater was present at the oxidation time of 6.10 h.

Potential development in dye-sensitized solar cells for renewable energy

CERN Document Server

Pandikumar, Alagarsamy

2013-01-01

The development of photovoltaic technology is expected to solve problems related to energy shortages and environmental pollution caused by the use of fossil fuels. Dye-sensitizedsolar cells (DSSCs) are promising next-generation alternatives to conventional silicon-based photovoltaic devices owing to their low manufacturing cost and potentially high conversion efficiency. This special topic volume addresses recent advances in the research on dye-sensitized solar cells. The focus of this special topic volume is on materials development (sensitizers, nanostructured oxide films, and electrolyte),

Glutamatergic modulation of synaptic-like vesicle recycling in mechanosensory lanceolate nerve terminals of mammalian hair follicles.

Science.gov (United States)

Banks, Robert W; Cahusac, Peter M B; Graca, Anna; Kain, Nakul; Shenton, Fiona; Singh, Paramjeet; Njå, Arild; Simon, Anna; Watson, Sonia; Slater, Clarke R; Bewick, Guy S

2013-05-15

Our aim in the present study was to determine whether a glutamatergic modulatory system involving synaptic-like vesicles (SLVs) is present in the lanceolate ending of the mouse and rat hair follicle and, if so, to assess its similarity to that of the rat muscle spindle annulospiral ending we have described previously. Both types of endings are formed by the peripheral sensory terminals of primary mechanosensory dorsal root ganglion cells, so the presence of such a system in the lanceolate ending would provide support for our hypothesis that it is a general property of fundamental importance to the regulation of the responsiveness of the broad class of primary mechanosensory endings. We show not only that an SLV-based system is present in lanceolate endings, but also that there are clear parallels between its operation in the two types of mechanosensory endings. In particular, we demonstrate that, as in the muscle spindle: (i) FM1-43 labels the sensory terminals of the lanceolate ending, rather than the closely associated accessory (glial) cells; (ii) the dye enters and leaves the terminals primarily by SLV recycling; (iii) the dye does not block the electrical response to mechanical stimulation, in contrast to its effect on the hair cell and dorsal root ganglion cells in culture; (iv) SLV recycling is Ca(2+) sensitive; and (v) the sensory terminals are enriched in glutamate. Thus, in the lanceolate sensory ending SLV recycling is itself regulated, at least in part, by glutamate acting through a phospholipase D-coupled metabotropic glutamate receptor.

Side Effects: Hair Loss (Alopecia)

Science.gov (United States)

Hair loss, also called alopecia, is a side effect of cancer treatments, such as chemotherapy and radiation therapy. Learn how to cope with and manage hair loss. Listen to tips from others who have experienced hair loss.

iNOS inhibits hair regeneration in obese diabetic (ob/ob) mice.

Science.gov (United States)

Sasaki, Mari; Shinozaki, Shohei; Morinaga, Hironobu; Kaneki, Masao; Nishimura, Emi; Shimokado, Kentaro

2018-07-02

Previous studies have shown that androgenic alopecia is associated with metabolic syndrome and diabetes. However, the detailed mechanism whereby diabetes causes alopecia still remains unclear. We focused on the inflammatory response that is caused by diabetes or obesity, given that inflammation is a risk factor for hair loss. Inducible nitric oxide synthase (iNOS) is known to be upregulated under conditions of acute or chronic inflammation. To clarify the potential role of iNOS in diabetes-related alopecia, we generated obese diabetic iNOS-deficient (ob/ob; iNOS-KO mice). We observed that ob/ob; iNOS-KO mice were potentiated for the transition from telogen (rest phase) to anagen (growth phase) in the hair cycle compared with iNOS-proficient ob/ob mice. To determine the effect of nitric oxide (NO) on the hair cycle, we administered an iNOS inhibitor intraperitoneally (compound 1400 W, 10 mg/kg) or topically (10% aminoguanidine) in ob/ob mice. We observed that iNOS inhibitors promoted anagen transition in ob/ob mice. Next, we administered an NO donor (S-nitrosoglutathione, GSNO), to test whether NO has the telogen elongation effects. The NO donor was sufficient to induce telogen elongation in wild-type mice. Together, our data indicate that iNOS-derived NO plays a role in telogen elongation under the inflammatory conditions associated with diabetes in mice. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

l-N-acetylcysteine protects outer hair cells against TNFα initiated ototoxicity in vitro.

Science.gov (United States)

Tillinger, Joshua A; Gupta, Chhavi; Ila, Kadri; Ahmed, Jamal; Mittal, Jeenu; Van De Water, Thomas R; Eshraghi, Adrien A

2018-03-07

The present study is aimed at determining the efficacy and exploring the mechanisms by which l-N-acetylcysteine (l-NAC) provides protection against tumor necrosis factor-alpha (TNFα)-induced oxidative stress damage and hair cell loss in 3-day-old rat organ of Corti (OC) explants. Previous work has demonstrated a high level of oxidative stress in TNFα-challenged OC explants. TNFα can potentially play a significant role in hair cell loss following an insult to the inner ear. l-NAC has shown to provide effective protection against noise-induced hearing loss in laboratory animals but mechanisms of this otoprotective effect are not well-defined. Rat OC explants were exposed to either: (1) saline control (N = 12); (2) TNFα (2 μg/ml, N = 12); (3) TNFα+l-NAC (5 mM, N = 12); (4) TNFα+l-NAC (10 mM, N = 12); or (5) l-NAC (10 mM, N = 12). Outer hair cell (OHC) density, levels of reactive oxygen species (ROS), lipid peroxidation of cell membranes, gluthathione activity, and mitochondrial viability were assayed. l-NAC (5 and 10 mM) provided protection for OHCs from ototoxic level of TNFα in OC explants. Groups treated with TNFα+l-NAC (5 mM) showed a highly significant reduction of both ROS (p l-NAC (5 mM) treated explants (p l-NAC is a promising treatment for protecting auditory HCs from TNFα-induced oxidative stress and subsequent loss via programmed cell death.

Topical Valproate Solution for Hair Growth

Directory of Open Access Journals (Sweden)

Anil Kakunje

2018-05-01

Full Text Available Valproate is used regularly in the treatment of various seizure disorders, bipolar disorder, migraine prophylaxis and off label in many other conditions. Alopecia or hair loss is cosmetic side effect of oral valproate administration. Hair loss with valproate is diffused, non-scarring and dose related. A large number of drugs may interfere with the hair cycle and produce hair loss. We have only a few drugs like Minoxidil, Finasteride used for hair regeneration and both have its own side effects and limitations. In contrast to oral ingestions of valproate causing hair loss, early experiments with topical Valproic acid cream showed hair regeneration. Valproic acid cream is currently unavailable in the market, alternatively, we do have valproate and divalproex solutions available in various strengths which have a potential to be used topically for hair regeneration. The side effects and cost of topical valproate solution could be much less than the available options in the market. Valproate solution topically has the potential to be used for hair growth.

Roothairless5, which functions in maize (Zea mays L.) root hair initiation and elongation encodes a monocot-specific NADPH oxidase.

Science.gov (United States)

Nestler, Josefine; Liu, Sanzhen; Wen, Tsui-Jung; Paschold, Anja; Marcon, Caroline; Tang, Ho Man; Li, Delin; Li, Li; Meeley, Robert B; Sakai, Hajime; Bruce, Wesley; Schnable, Patrick S; Hochholdinger, Frank

2014-09-01

Root hairs are instrumental for nutrient uptake in monocot cereals. The maize (Zea mays L.) roothairless5 (rth5) mutant displays defects in root hair initiation and elongation manifested by a reduced density and length of root hairs. Map-based cloning revealed that the rth5 gene encodes a monocot-specific NADPH oxidase. RNA-Seq, in situ hybridization and qRT-PCR experiments demonstrated that the rth5 gene displays preferential expression in root hairs but also accumulates to low levels in other tissues. Immunolocalization detected RTH5 proteins in the epidermis of the elongation and differentiation zone of primary roots. Because superoxide and hydrogen peroxide levels are reduced in the tips of growing rth5 mutant root hairs as compared with wild-type, and Reactive oxygen species (ROS) is known to be involved in tip growth, we hypothesize that the RTH5 protein is responsible for establishing the high levels of ROS in the tips of growing root hairs required for elongation. Consistent with this hypothesis, a comparative RNA-Seq analysis of 6-day-old rth5 versus wild-type primary roots revealed significant over-representation of only two gene ontology (GO) classes related to the biological functions (i.e. oxidation/reduction and carbohydrate metabolism) among 893 differentially expressed genes (FDR <5%). Within these two classes the subgroups 'response to oxidative stress' and 'cellulose biosynthesis' were most prominently represented. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.