Search results for: adverse drug reaction reporting

Authors: Mahzad Yousefi, Azin Tavakoli

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Periodontal disease is an inflammatory reaction; therefore, it is predicted that changes may occur in some inflammatory parameters that can be detected in routine blood tests. The objective of this study was to evaluate the hematological and biochemistry changes that occur in dogs affected with advanced stages of periodontal disease. 87 dogs were diagnosed with periodontal disease (PD group), and 76 healthy dogs entered the study. The PD dogs had been affected with periodontitis stage 3 or 4 and were candidates for any dental extractions. The healthy dogs were either referred for annual checkups or for issuing health travel certificates that their owners asked for complete lab tests. Neither the diseased nor healthy subjects had a history of infectious, or other general health problems or surgery in the past 3 months. Age, as well as all hematologic including PCV, WBC and RBC count, Hb, MCV, MCH, MCHC, PLT, CBC, NLR, and biochemistry data, including total protein, albumin, glucose, BUN, Creatinine, ALT, AST, and ALP, were recorded and analyzed statistically. Results confirmed that aging has a significant direct relationship with the advanced stages of periodontal disease. Mild leukocytosis occurred in the diseased group; however, it was not significant. Also, the mean total protein of the PD group was lower than that of the healthy dogs, and serum levels of albumin were found to be lower significantly in the diseased group (P<0.05). Mean ±SD amount of Platelet, MCH, and ALT were significantly higher in the diseased group in comparison to the healthy dogs (P<0.05). No significant differences were reported in other evaluated parameters. It is concluded that CBC indices of PD dogs are not systemic inflammatory; however, only a decrease in albumin showed inflammatory responses. Some indices in routine laboratory tests can be changed significantly during advanced stages of the periodontal disease dogs.

Keywords: periodontal disease, dogs, hematological factors, advanced stages, blood tests

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Authors: G. Singh, H.Schuster, U. Füssel

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The stability of electric arc and durability of electrode tip used in Tungsten Inert Gas (TIG) welding demand a metallurgical study about the chemical transport mechanism of emitter oxide particles in tungsten electrode during its real welding conditions. The tungsten electrodes doped with emitter oxides of rare earth oxides such as La₂O₃, Th₂O₃, Y₂O₃, CeO₂ and ZrO₂ feature a comparatively lower work function than tungsten and thus have superior emission characteristics due to lesser surface temperature of the cathode. The local change in concentration of these emitter particles in tungsten electrode due to high temperature diffusion (chemical transport) can change its functional properties like electrode temperature, work function, electron emission, and stability of the electrode tip shape. The resulting increment in tip surface temperature results in the electrode material loss. It was also observed that the tungsten recrystallizes to large grains at high temperature. When the shape of grain boundaries are granular in shape, the intergranular diffusion of oxide emitter particles takes more time to reach the electrode surface. In the experimental work, the microstructure of the used electrode's tip surface will be studied by scanning electron microscope and reflective X-ray technique in order to gauge the extent of the diffusion and chemical reaction of emitter particles. Besides, a simulated model is proposed to explain the effect of oxide particles diffusion on the electrode’s microstructure, electron emission characteristics, and electrode tip erosion. This model suggests metallurgical modifications in tungsten electrode to enhance its erosion resistance.

Keywords: rare-earth emitter particles, temperature-dependent diffusion, TIG welding, Tungsten electrode

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Authors: Rachmat Mauludin, Novita R. Kusuma, Diky Mudhakir

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Famotidine (FMT) is one of used substances in the treatment of hiperacidity and peptic ulcer, administered orally and parenterally via intravenous injection. Oral administration, which is more favorable, has been reported to have many obstacles in the process of the treatment, includes decreasing the bioavailability of FMT. This research was aimed to prepare FMT in form of solid lipid nanoparticles (SLN) with size ranging between 100-200 nm. The research was carried out also by optimizing factors that may affect physical stability of SLN. Formulation of Famotidine SLN was carried out by optimizing factors, such as duration of homogenization and sonication, lipid concentration, stabilizer composition and stabilizer concentration. SLN physical stability was evaluated (particle size distribution) for 42 days in 3 diferent temperatures. Entrapment efficiency and drug loading was determined indirectly and directly. The morphology of SLN was visualized by transmission electron microscope (TEM). In vitro release study of FMT was conducted in 2 mediums, at pH of 1.2 and 7.4. Chemical stability of FMT was determined by quantifying the concentration of FMT within 42 days. Famotidin SLN consisted of GMS as lipid and poloxamer 188, lecithin, and polysorbate 80 as stabilizers. Homogenization and sonication was performed for 5 minutes and 10 minutes. Physyical stability of nanoparticles at 3 different temperatures was no significant difference. The best formula was physically stable until 42 days with mean particle size below 200 nm. Nanoparticles produced was able to entrap FMT until 86.6%. Evaluation by TEM showed that nanoparticles was spherical and solid. In medium pH of 1.2, FMT was released only 30% during 4 hour. On the other hand, within 4 hours SLN could release FMT completely in medium pH of 7.4. The FMT concentration in nanoparticles dispersion was maintained until 95% in 42 days (40oC, RH 75%). Famotidine SLN was able to be produced with mean particle size ranging between 100-200 nm and physically stable for 42 days. SLN could be loaded by 86,6% of FMT. Morphologically, obtained SLN was spheric and solid. During 4 hours in medium pH of 1.2 and 7.4, FMT was released until 30% and 100%, respectively.

Keywords: solid lipid nanoparticle (SLN), famotidine (FMT), physicochemical properties, release study

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Authors: Young-Min Kang

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M-type Sr-hexaferrites (SrFe12O19) is one of the most utilized materials in permanent magnets due to their low price, outstanding chemical stability, and appropriate hard magnetic properties. For a M-type Sr-hexaferrite with a saturation magnetization (MS) of ~74.0 emu/g the practical limits of remanent flux density (Br) and maximum energy product (BH) max are ~4.6 kG and ~5.3 MGOe. Meanwhile, W-type hexaferrite (SrFe18O27) with higher MS ~81emu/g can be a good candidate for the development of enhanced ferrite magnet. However the W-type hexaferrite is stable at the temperature over 1350 ºC in air, and thus it is hard to control grain size and the coercivity. We report here high-MS M-W composite hexaferrites synthesized at 1250 ºC in air by doping Ca, Co, Mn, and Zn into the hexaferrite structures. The hexaferrites samples of stoichiometric SrFe12O19 (SrM) and Ca-Co-Mn-Zn doped hexaferrite (Sr0.7Ca0.3Fen-0.6Co0.2Mn0.2Zn0.2Oa) were prepared by conventional solid state reaction process with varying Fe content (10 ≤ n ≤ 17). Analysis by x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) were performed for phase identification and microstructural observation respectively. Magnetic hysteresis curves were measured using vibrating sample magnetometer (VSM) at room temperature (300 K). Single M-type phase could be obtained in the non-doped SrM sample after calcinations at the range of 1200 ºC ~ 1300 ºC, showing MS in the range of 72 ~ 72.6 emu/g. The Ca-Co-Mn-Zn doped SrM with Fe content, 10 ≤ n ≤ 13, showed both M and W-phases peaks in the XRD after respective calcinations at 1250 ºC. The sample with n=13 showed the MS of 70.7, 75.3, 78.0 emu/g, respectively, after calcination at 1200, 1250, 1300 ºC. The high MS over that of non-doped SrM (~72 emu/g) is attributed to the volume portion of W-phase. It is also revealed that the high MS W-phase could not formed if only one of the Ca, Co, Zn is missed in the substitution. These elements are critical to form the W-phase at the calcinations temperature of 1250 ºC, which is 100 ºC lower than the calcinations temperature for non-doped Sr-hexaferrites.

Keywords: M-type hexaferrite, W-type hexaferrite, saturation magnetization, low-temperature synthesis

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Authors: Roghaieh Parvizsedghy, Seyed Mojtaba Sadrameli

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Diminishing oil reserves, deteriorating health standards because of greenhouse gas emissions and associated environmental impacts have emerged biofuel production. Vegetable oils are proved to be valuable feedstock in these growing industries as they are renewable and potentially inexhaustible sources. Thermal Cracking of vegetable oils (triglycerides) leads to production of biofuels which are similar to fossil fuels in terms of composition but their combustion and physical properties have limits. Acrolein (very poisonous gas) and water production during cracking of triglycerides occurs because of presence of glycerin in their molecular structure. Transesterification of vegetable oil is a method to extract glycerol from triglycerides structure and produce methyl ester. In this study, castor methyl ester was used for thermal cracking in order to survey the efficiency of this method to produce bio-gasoline and bio-diesel. Thus, several experiments were designed by means of central composite method. Statistical studies showed that two reaction parameters, namely cracking temperature and feed flowrate, affect products yield significantly. At the optimized conditions (480 °C and 29 g/h) for maximum bio-gasoline production, 88.6% bio-oil was achieved which was distilled and separated as bio-gasoline (28%) and bio-diesel (48.2%). Bio-gasoline exposed a high octane number and combustion heat. Distillation curve and Reid vapor pressure of bio-gasoline fell in the criteria of standard gasoline (class AA) by ASTM D4814. Bio-diesel was compatible with standard diesel by ASTM D975. Water production was negligible and no evidence of acrolein production was distinguished. Therefore, thermal cracking of castor methyl ester could be used as a method to produce valuable biofuels.

Keywords: bio-diesel, bio-gasoline, castor methyl ester, thermal cracking, transesterification

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Authors: Yetti Marlida, Harnentis, Yuliaty Shafan Nur

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Background: Tempoyak is a dish derived from fermented durian fruit. Tempoyak is a food consumed as a side dish when eating rice. Besides being eaten with rice, tempoyak can also be eaten directly. But this is rarely done because many cannot stand the sour taste and aroma of the tempoyak itself. In addition, tempoyak can also be used as a seasoning. The taste of tempoyak is acidic, this occurs because of the fermentation process in durian fruit meat which is the raw material. Tempoyak is already very well known in Indonesia, especially in Padang, Bengkulu, Palembang, Lampung, and Kalimantan. Besides that, this food is also famous in Malaysia. The purpose of this research is to improvement production of γ-aminobutyric acid (GABA) by Lactobacillus plantarum isolated from indigenous fermented durian (tempoyak). Selected Lactic Acid Bacteria (LAB) previously isolated from indigenous fermented durian (tempoyak) that have ability to produce γ-aminobutyric acid (GABA). The study was started with identification of selected LAB by 16 S RNA, followed optimation of GABA production by culture condition using different initial pH, temperature, glutamate concentration, incubation time, carbon and nitrogen sources. Results: The result from indentification used polymerase chain reaction of 16S rRNA gene sequences and phylogenetic analysis was Lactobacillus plantarum (coded as Y3) with a sequenced length of 1400bp. The improvement of Gaba production was found highest at pH: 6.0; temperature: 30 °C; glutamate concentration: 0.4%; incubation time: 60 h; glucose and yeast extract as carbon and nitrogen sources. Conclusions: GABA can be produced with the optimum condition fermentation were 66.06 mM.

Keywords: lactic acid bacteria, γ-amino butyric acid, indigenous fermented durian, PCR

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Authors: Kefale W. Yizengaw, Delele Worku Ayele, Jyh-Chiang Jiang

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The catalytic co-conversion of CO₂ and CH₄ to value-added compounds has become one of the promising approaches to addressing global climate change by having valuable fossil fuels. Thedirect co-conversion of CO₂ and CH₄ to value-added compounds is attractive but tremendously challenging because of both molecules' thermodynamic stability and kinetic inertness. In the present study, a single iridium atom doped and a single oxygen atom defect hematite (110)surface model catalyst, which can comprehend direct C–O coupling based on simultaneous activation of CO2 and CH4 was studied using density functional theory plus U (DFT + U)calculations. The presence of dual active sites on the Ir/Fe₂O₃(110)-OV surface catalyst enablesCO₂ activation on the Ir site and CH₄ activation at the defect site. The electron analysis for the theco-adsorption of CO₂ and CH₄ deals with the electron redistribution on the surface and clearly shows the synergistic effect for simultaneous CO₂ and CH₄ activation on Ir/α- Fe₂O₃(110)-OVsurface. The microkinetic analysis shows that the dissociation of CH4 to CH3 * and H* plays an excellent role in the C–O coupling. The coverage analysis for the intermediate products of the microkinetic simulation results indicates that C–O coupling is the reaction limiting step. Finally, after the CH₃O* intermediate product species is produced, the radical hydrogen species spontaneously diffuse to the CH3O* intermediate product to form methanol at around 490 [K]. The present work provides mechanistic and kinetic insights into the direct C–O coupling of CO₂and CH₄, which could help design more-efficient catalysts.

Keywords: co-conversion, C–O coupling, doping, oxygen vacancy, microkinetic

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Authors: Masaaki Ii, Takashi Saito, Yasuhiko Tabata, Shintaro Nemoto

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Background: Clinical trials of autologous adipose-derived stem cell (AdSC) therapy for ischemic heart diseases (IHD) are now on-going. We have investigated the hypothesis that combination of AdSCs and statin, an agent with pleiotropic effects, could augment the therapeutic effect on myocardial infarction (MI). Methods and Results: Human AdSC functions with different doses of simvastatin-conjugated nanoparticle (STNP) uptake were evaluated by in vitro assays. STNP promoted the migration activity without changing the proliferation activity, and also up-regulated growth factors. Next, MI was induced by LAD ligation in nude mice, and the mice were assigned in the following groups 3 days after MI: 1) PBS (control), 2) NP-AdSCs (50000 cells), 3) STNP, and 4) STNP-AdSCs (50000 cells). Cardiac functional recovery assessed by echocardiography was improved at 4 weeks after surgery in STNP-AdSC group. Masson’s trichrome-stained sections revealed that LV fibrosis length was reduced, and the number of TUNEL-positive cardiomyocytes was less in STNP-AdSC group. Surprisingly, a number of de novo endogenous Nkx-2.5/GATA4 positive immature cardiomyocytes as well as massive vascular formation were observed in outer layer of infarcted myocardium despite of a few recruited/retained transfused STNP-AdSCs 4 weeks after MI in STNP-AdSC group. Finally, massive myocardial regeneration was observed 8 weeks after MI. Conclusions: Intravenously injected small number of statin nanoparticle-loaded hAdSCs exhibited a potent therapeutic effect inducing endogenous cardiac tissue regeneration.

Keywords: statin, drug delivery system, stem cells, cardiac regeneration

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Authors: Daisy Dutta, Chhanda Chakraborti

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Background and significance of the study: Menstrual Hygiene Management (MHM) is poor in many Lower and Middle-Income Countries (LMIC) such as India. Poor and inadequate menstrual hygiene has an adverse effect on the health and social life of adolescent girls and women. There are many well-known barriers to adequate Menstrual Hygiene Management (MHM); e.g., lack of awareness, lack of WASH (Water, Sanitation and Hygiene) facilities, lack of affordable menstrual absorbents, etc. But, there is a unique barrier which is very much avoidable; i.e., lack of proper guidance and counseling about menstruation. Menstruation is associated with various social and cultural restrictions and taboos and being a taboo topic; often there is no discussion in the society on this topic. Thus, many adolescent girls encounter the menarche with a lot of unnecessary and avoidable trauma, stress and awkwardness. This trauma, stress, and anxiety are even more prevalent among adolescent girls residing in rural areas. This study argues that this unnecessary stress and anxiety of the adolescent girls can be alleviated by reinforcing social support and adequate information and guidance about MHM and eliminating the futile socio-cultural restrictions during menstruation. Methodology: A qualitative study was conducted in a North-eastern State of India where 45 adolescent girls were interviewed both from rural and urban areas. The adolescent girls were asked about their experiences of stress and anxiety on their first menstruation, their preparedness for menarche, their source of information and guidance, their hygiene-practices, and the various restrictions they follow. Findings: Maximum number of girls did not receive any information about menstruation before menarche. Most of them reported that they were terrified about their first menstruation as they were unprepared. Among those who were aware before menarche, reported that they did not receive proper guidance to manage their menstruation in a hygienic manner. Hygiene-related practices are also influenced by their knowledge about MHM. In maximum cases, girls are bound to follow certain cultural and religious restrictions even if they don’t want to follow which created additional stress in managing their menstruation with dignity. Conclusion: Lack of proper guidance and counseling about menstruation and MHM along with an array of socio-cultural restrictions can enhance a negative attitude in adolescent girls towards menstruation due to which they have to go through an extra and unnecessary burden of stress and trauma. This stress and trauma is preventable by improving the provisions of proper guidance and counseling about menstruation in a supportive environment.

Keywords: adolescent girls, menstrual hygiene management, socio-cultural restrictions, stress, trauma

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Authors: Svitlana Antonenko, Gennady Telegeev

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Introductive statement: The development of chronic myeloid leukemia (CML) is caused by Bcr-Abl oncoprotein. Modern treatments with tyrosine kinase inhibitors are greatly complicated by the mutational variability of the Bcr-Abl oncoprotein, which causes drug resistance. Therefore, there is an urgent need to develop new approaches to the treatment of the disease, which will allow modeling the level of Bcr-Abl oncoprotein in the cell. Promising in this direction is the identification of proteases that can selectively promote cellular proteolysis of oncoproteins. The aim of the study was to study the effect of the interaction of Bcr-Abl with deubiquitinase USP1 on the level of oncoprotein in CML cells. Methodology: K562 cells were selected for the experiment. Сells were incubated with ML323 inhibitor for 24 hours. Precipitation of endogenous proteins from K562 cell lysate was performed using anti-Bcr-Abl antibodies. Cell lysates and precipitation results were studied by Western blot. Subcellular localization of proteins was studied by immunofluorescence analysis followed by confocal microscopy. The results were analyzed quantitatively and statistically. Major findings: The Bcr-Abl/USP1 protein complex was detected in CML cells, and it was found that inhibition of USP1 deubiquitinating activity by the compound ML323 leads to disruption of this protein complex and a decrease in the level of Bcr-Abl oncoprotein in cells. The interaction of Bcr-Abl with USP1 may result in deubiquitination of the oncoprotein, which disrupts its proteasomal degradation and leads to the accumulation of CML in cells. Conclusion: We believe that the interaction of oncoprotein with USP1 may be one of the prerequisites that contribute to malignant cell transformation due to the deubiquitination of oncoprotein, which leads to its accumulation and disease progression. A correlation was found between the deubiquitinating activity of USP1 and the level of oncoprotein in CML cells. Thus, we identify deubiquitinase USP1 as a promising therapeutic target for the development of a new strategy for the treatment of CML by modulating the level of Bcr-Abl in the cell.

Keywords: chronic myeloid leukemia, Bcr-Abl, USP1, deubiquitination Bcr-Abl, K562 cell

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Authors: Suchana Marahatta, Sabina Bhattarai, Bishnu Hari Paudel, Dilip Thakur

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Background: Every year thousands of patients develop nerve damage and disabilities as a result of leprosy which can be prevented by early detection and treatment. So, early detection and treatment of nerve function impairment is of paramount importance in leprosy. Objectives: To assess the electrophysiological pattern of the peripheral nerves in leprosy patients and to compare it with clinical assessment tools. Materials and Methods: In this comparative cross-sectional study, 74 newly diagnosed leprosy patients without reaction were enrolled. They underwent thorough evaluation for peripheral nerve function impairment using clinical tests [i.e. nerve palpation (NP), monofilament (MF) testing, voluntary muscle testing (VMT)] and nerve conduction study (NCS). Clinical findings were compared with that of NCS using SPSS version 11.5. Results: NCS was impaired in 43.24% of leprosy patient at the baseline. Among them, sensory NCS was impaired in more patients (32.4%) in comparison to motor NCS (20.3%). NP, MF, and VMT were impaired in 58.1%, 25.7%, and 9.4% of the patients, respectively. Maximum concordance of monofilament testing and sensory NCS was found for sural nerve (14.7%). Likewise, the concordance of motor NP and motor NCS was the maximum for ulnar nerve (14.9%). When individual parameters of the NCS were considered, amplitude was found to be the most frequently affected parameter for both sensory and motor NCS. It was impaired in 100% of cases with abnormal NCS findings. Conclusion: Since there was no acceptable concordance between NCS findings and clinical findings, we should consider NCS whenever feasible for early detection of neuropathy in leprosy. The amplitude of both sensory nerve action potential (SNAP) and compound nerve action potential (CAMP) could be important determinants of the abnormal NCS if supported by further studies.

Keywords: leprosy, nerve function impairment, neuropathy, nerve conduction study

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Authors: Iis Diatin, Yani Hadiroseyani, Muhammad Mujahid, Ahmad Teduh, Juang R. Matangaran

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One of silica quarry managed by a mining company is located at Sukabumi District of West Java Province Indonesia with an area of approximately 70 hectares. Since 2013 this company stopped the mining activities. The company tries to restore the ecosystem post-mining with rehabilitation activities such as reclamation and revegetation of their ex-mining area. After three years planting the area the trees grown well. Not only planting some tree species but also some cover crop has covered the soil surface. There are two settling ponds located in the middle of the ex-mining area. Those settling pond were built in order to prevent the effect of acid mine drainage. Acid mine drainage (AMD) or the acidic water is created when sulphide minerals are exposed to air and water and through a natural chemical reaction produce sulphuric acid. AMD is the main pollutant at the open pit mining. The objective of the research was to analyze the effect of revegetation on water quality change at the settling pond. The physical and chemical of water quality parameter were measured and analysed at site and at the laboratory. Physical parameter such as temperature, turbidity and total organic matter were analyse. Also heavy metal and some other chemical parameter such as dissolved oxygen, alkalinity, pH, total ammonia nitrogen, nitrate and nitrite were analysed. The result showed that the acidity of first settling pond was higher than that of the second settling pond. Both settling pond water’s contained heavy metal. The turbidity and total organic matter were the parameter of water quality which become better after revegetation.

Keywords: acid mine drainage, ex-mining area, revegetation, settling pond, water quality

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Authors: Rahul Jarariya

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The textile industry uses various types of dyes and discharges a lot of highly coloured wastewater. It impacts the environment like allergic reaction, respiratory, skin problems, irritation to a mucous membrane, the upper respiratory tract has to the fore, Intoxicated dye discharges 40 to 50,000 tons with great concern. Spinel ferrites gained a lot of attention due to their wide application area from biomedical to wastewater treatment. Generally, spinel ferrite is known as M-Fe2O4. Spinel type nanoparticles possess high suspension stability. The synthesis method of Microwave solution combustion (MC) method is effective for nanoscale materials, including oxides, metals, alloys, and sulfides, works as fast and energy-efficient during the process. The review focuses on controlling, nanostructure and doping. The influence of the fuel concentration and the post-treatment temperature on the structural and magnetic properties. The effects of amounts of fuel and phase changes, particle size and shape, and magnetic properties can be characterized by various techniques. Urea is the most commonly used fuel. Ethanol or n-butanol is apt for removing impurities. As a result of the materials gives fine purity. Photocatalysis phenomena act with catalyst dosage to degrade dye from wastewater. Visible light responsive produces a large amount of hydroxyl (•OH) radical made the degradation efficiency of Rh21 type dye. It develops a narrow bandgap to make it suitable for enhanced photocatalytic activity.

Keywords: microwave solution combustion method, normal spinel, doped spinels, magnetic property, Rb21

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Authors: Ismail I. Abo-Ghanema, Faheim E. Wehaish, Rasha M. Saleh , Walaa F. Awadin, Mohamed F. Elshal

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The antidiabetic activity of myrrh and ginseng ethanolic extracts were investigated in streptozotocin (STZ)-induced diabetic rats. Thirty male albino rats were divided into five groups, each consisted of six rats. The first group (G1) is the negative control that was fed basal diet, the second group (G2) was injected with STZ and received no treatment, the third group (G3) injected with STZ and received metformin (50 mg/kg, b.wt) as standard anti-diabetic drug, the fourth group (G4) injected with STZ and ginseng (50 mg/kg, b.wt), the fifth group (G5) injected with STZ and received myrrh (500 mg/kg, b.wt). As compared with G1-group, STZ injection increased blood concentrations of glucose (6.2 fold), glycated hemoglobin (HbA1c) (2.51 fold), aspartateaminotransferase (AST), and alanine aminotransferase (ALT) (2.64, 4.60 fold respectively), creatinine (2.91 fold), cholesterol (1.79 fold), triglycerides (2.06 fold), low density lipoprotein-cholesterol (LDL) (2.92 fold), nitric oxide (NO) (20.18 fold), and malondialdehyde (MDA) (2.25 fold), whereas it decreased blood insulin (0.40 fold), albumin (0.60 fold), high density lipoprotein-cholesterol (HDL) (0.33 fold), and reduced glutathione (GSH) (0.49 fold). Vascular permeability index (VPI as measured by Evan's Blue; EB extravasations test) was significantly increased in the skin of diabetic animals (9.6 fold) when compared with the G1-group. In addition, histological alterations in liver, pancreas, kidneys and heart were observed. After 4 weeks of treatment, rats in G4 and G5 showed significant corrections in the all measured parameters and indices. In conclusions, the ethanolic extracts of ginseng and myrrh exhibited promising and safe anti-diabetic activity especially on peripheral circulation as manifested by decreased vascular permeability and improved histopathological alterations of examined organs and insulin secretion. Hence, it may be pursued for their clinical usefulness in the management of diabetes mellitus (DM) and associated vascular complications.

Keywords: diabetic rats, peripheral circulation, natural plants, myrrh, ginseng

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Authors: Pernille K. Christiansen, Mette Maria Skjøth, Line Lorenzen, Eva Draborg, Christina Anne Vinter, Trine Kjær, Mette Juel Rothmann

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Background and aims: Overweight and obesity are an increasing challenge on a global level. In Denmark, more than one-third of all pregnant women are overweight or obese, and many women exceed the gestational weight gain recommendations from the Institute of Medicine. Being overweight or obese, is associated with a higher risk of adverse maternal and fetal outcomes, including gestational diabetes and childhood obesity. Thus, it is important to focus on the women’s lifestyles between their pregnancies to lower the risk of gestational weight retention in the long run. The objective of this study was to explorer what barriers and challenges postpartum women experience with respect to healthy lifestyles during the postpartum period and to access whether an Information Technology based intervention might be a supportive tool to assist and motivate postpartum women to a healthy lifestyle. Materials and methods: The method is inspired by participatory design. A systematic text condensation was applied to semi-structured focus groups. Five focus group interviews were carried out with a total of 17 postpartum women and two interviews with a total of six health professionals. Participants were recruited through the municipality in Svendborg, Denmark, and at Odense University Hospital in Odense, Denmark, during a four-month period in early 2018. Results: From the women’s perspective, better assistance is needed from the health professionals to obtain or maintain a healthy lifestyle. The women need tools that inform and help them understand and prioritise their own health-related risks, and to motivate them to plan and take care of their own health. As the women use Information Technology on a daily basis, the solution could be delivered through Information Technology. Finally, there is room for engaging the partner more in the communication related to the baby and family’s lifestyle. Conclusion: Postpartum women need tools that inform and motivate a healthy lifestyle postpartum. The tools should allow access to high-quality information from health care professionals, when the information is needed, and also allow engagement from the partner. Finally, Information Technology is a potential tool for delivering tools.

Keywords: information technology, lifestyle, overweight, postpartum

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Authors: Maria Bercea, Monica Diana Olteanu

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Investigation of polymer systems able to change inside of the body into networks represent an attractive approach, especially when there is a minimally invasive and patient friendly administration. Pharmaceutical formulations based on Pluronic F127 [poly (oxyethylene) (PEO) blocks (70%) and poly(oxypropylene) (PPO) blocks (30%)] present an excellent potential as drug delivery systems. The use of Pluronic F127 alone as gel-forming solution is limited by some characteristics, such as poor mechanical properties, short residence time, high permeability, etc. Investigation of the interactions between the natural and synthetic polymers and surfactants in solution is a subject of great interest from both scientific and practical point of view. As for example, formulations based on Pluronics and chitosan could be used to obtain dual phase transition hydrogels responsive to temperature and pH changes. In this study, different materials were prepared by using poly(vinyl alcohol), chitosan solutions mixed with aqueous solutions of Pluronic F127. The rheological properties of different formulations were investigated in temperature sweep experiments as well as at a constant temperature of 37oC for exploring in-situ gel formation in the human body conditions. In addition, some viscometric investigations were carried out in order to understand the interactions which determine the complex behaviour of these systems. Correlation between the thermodynamic and rheological parameters and phase separation phenomena observed for the investigated systems allowed the dissemination the constitutive response of polymeric materials at different external stimuli, such as temperature and pH. The rheological investigation demonstrated that the viscoelastic moduli of the hydrogels can be tuned depending on concentration of different components as well as pH and temperature conditions and cumulative contributions can be obtained.

Keywords: hydrogel, polymer mixture, stimuli responsive, biomedical applications

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Authors: Chia-Chia Chang, Jhen-Ting Huang, Hu-Cheng Weng, An-Ya Lo

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This study developed a simple hierarchical porous carbon (HPC) synthesis process and used for supercapacitor application. In which, mesopore provides huge specific surface area, meanwhile, macropore provides excellent mass transfer. Thus the hierarchical porous electrode improves the charge-discharge performance. On the other hand, cerium oxide (CeO2) have also got a lot research attention owing to its rich in content, low in price, environmentally friendly, good catalytic properties, and easy preparation. Besides, a rapid redox reaction occurs between trivalent cerium and tetravalent cerium releases oxygen atom and increase the conductivity. In order to prevent CeO2 from disintegration under long-term charge-discharge operation, the CeO2 carbon porous materials were was integrated as composite material in this study. For in the ex-situ analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) analysis were adopted to identify the surface morphology, crystal structure, and microstructure of the composite. 77K Nitrogen adsorption-desorption analysis was used to analyze the porosity of each specimen. For the in-situ test, cyclic voltammetry (CV) and chronopotentiometry (CP) were conducted by potentiostat to understand the charge and discharge properties. Ragone plot was drawn to further analyze the resistance properties. Based on above analyses, the effect of macropores/mespores and the CeO2/HPC ratios on charge-discharge performance were investigated. As a result, the capacitance can be greatly enhanced by 2.6 times higher than pristine mesoporous carbon electrode.

Keywords: hierarchical porous carbon, cerium oxide, supercapacitor

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Authors: Wajih Abbassi, Zouhaier Ben Khelifa

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The present research points towards the empirical validation of three options valuation models, the ad-hoc Black-Scholes model as proposed by Berkowitz (2001), the constant elasticity of variance model of Cox and Ross (1976) and the Kou jump-diffusion model (2002). Our empirical analysis has been conducted on a sample of 26,974 options written on three indexes, the S&P 500, Nasdaq 100 and the Russell 2000 that were negotiated during the year 2007 just before the sub-prime crisis. We start by presenting the theoretical foundations of the models of interest. Then we use the technique of trust-region-reflective algorithm to estimate the structural parameters of these models from cross-section of option prices. The empirical analysis shows the superiority of the Kou jump-diffusion model. This superiority arises from the ability of this model to portray the behavior of market participants and to be closest to the true distribution that characterizes the evolution of these indices. Indeed the double-exponential distribution covers three interesting properties that are: the leptokurtic feature, the memory less property and the psychological aspect of market participants. Numerous empirical studies have shown that markets tend to have both overreaction and under reaction over good and bad news respectively. Despite of these advantages there are not many empirical studies based on this model partly because probability distribution and option valuation formula are rather complicated. This paper is the first to have used the technique of nonlinear curve-fitting through the trust-region-reflective algorithm and cross-section options to estimate the structural parameters of the Kou jump-diffusion model.

Keywords: jump-diffusion process, Kou model, Leptokurtic feature, trust-region-reflective algorithm, US index options

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Authors: E. Riani, T. T. Irawadi, S. Nurjanah, K. Syamsu, E. G. Said, Suprihatin, M. R. Cordova

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Especially coastal, Indonesian and Chinese communities have utilized sandfish to improve reproduction quality of men. This study aimed to examine the nutrition on sandfish flesh that has the potency to improve reproduction quality of men. The materials used were sandfish with weight of 200-500 g, and then analysis of proximate, analysis of amino acid, analysis of fatty acid and analysis of mineral contained in the sandfish were performed. The results showed that protein content (39.96%) was the main component of the flesh; the carbohydrate and fat were 25.43% and 4.18%, respectively. Sandfish powder contains several essential amino acids and nonessential amino acids. Nine of ten amino acids needed by human body are contained in sandfish powder, i.e. arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, tryptophan, threonine and valine; only tryptophan that are not contained in sandfish powder. Sandfish powder contains saturated fatty acid kaproat, kaprilat, kaprat, laurat, miristat, stearat, arakhidat and behenat; monosaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). MUFA is composed of fatty acid oleat, while PUFA is composed fatty acid omega 3 (linonenat, eicosapentaenoic acid and docosahexaenoic acid) and omega 6 (linoleat and arakhidonat). The minerals contained in sandfish powder are macrominerals and microminerals. Based on the findings, the nutrition in sandfish powder has a good potency to improve reproduction of men, especially PUFA for the maturation of spermatozoa, zinc for production function and spermatogenesis, motility of spermatozoa, acromoson reaction; Mg for transformation of genetic information and motility of spermatozoa; calcium for spermatogenesis, capacity and fertilization of spermatozoa. Thus, sandfish flesh powder has the potency to improve reproduction quality of men.

Keywords: sandfish flesh powder, nutrition, reproduction quality, men

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Authors: Feras Darwish Elhajji, Alberto Berardi, Manal Ayyash, Iman Basheti

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The concept of the use of probiotics for humans now has been known for decades however, their intake by the Jordanian population seems to be less common when compared to population in the developed countries. Community pharmacy is the main supplier of probiotics, however, after conducting an extensive literature review, not any published research article could be found talking about the role, knowledge, and practice of the pharmacists in the area of probiotics. The main aim of this study was to evaluate the level of knowledge about probiotics and their dispensing practice in community pharmacies in Jordan. Community pharmacy staff (pharmacists and technicians) in Amman and north of Jordan were randomly selected to complete an anonymous questionnaire that had been pre-tested and validated. Ethical approval was obtained from the university ethics committee. The questionnaire included the following sections: demographics, knowledge and perceptions about probiotics, and role of the pharmacist Pharmacists and technicians were visited and interviewed in 281 community pharmacies. Asking about probiotics, 90.4% of them said that they know what probiotics are, although only 29.5% agreed that pharmacy staff in Jordan have good knowledge about probiotics, and 88.3% agreed that pharmacy staff in Jordan need more training and knowledge about probiotics. Variables that were significantly related to knowledge about probiotics were being a pharmacist (ρ= 0.012), area of the community pharmacy (ρ= 0.019), and female staff (ρ= 0.031) after conducting logistic regression statistical analysis. More than two-thirds of the participants thought that probiotics are classified as dietary supplements by Jordan Food and Drug Administration (JFDA). Of those who knew probiotics, the majority of them – 76.8% and 91.7% – agreed that probiotics are effective and safe, respectively. Believing in efficacy of the probiotics was significantly associated with answering their use to be with or after antibiotic administration and to increase normal flora gut population (ρ= 0.007). Efficacy was also significantly associated with recommending probiotics to consumers by the pharmacist (ρ< 0.001) and by the doctor (ρ= 0.041). At the same time, the concept of safety was mainly associated with their use for flatulence and gases (ρ= 0.048). Level of knowledge about probiotics and their uses, efficacy and safety amongst community pharmacy staff in Jordan is found to be good. However, this level can be raised in the future, especially knowledge about uses of probiotics.

Keywords: community pharmacy, Jordan, prebiotics, probiotics

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Authors: Zainab Bibi, Afsheen Aman, Shah Ali Ul Qader

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Endo-β-1,4-xylanases [EC 3.2.1.8] are one of the major groups of enzymes that are involved in degradation process of xylan and have several applications in food, textile and paper processing industries. Due to broad utility of endo-β-1,4-xylanase, researchers are focusing to increase the productivity of this hydrolase from various microbial species. Harsh industrial condition, faster reaction rate and efficient hydrolysis of xylan with low risk of contamination are critical requirements of industry that can be fulfilled by synthesizing the enzyme with efficient properties. In the current study, a newly isolated thermophile Geobacillus stearothermophilus KIBGE-IB29 was used in order to attain the maximum production of endo-1,4-β-xylanase. Bacterial culture was isolated from soil, collected around the blast furnace site of a steel processing mill, Karachi. Optimization of various nutritional and physical factors resulted the maximum synthesis of endo-1,4-β-xylanase from a thermophile. High production yield was achieved at 60°C and pH-6.0 after 24 hours of incubation period. Various nitrogen sources viz. peptone, yeast extract and meat extract improved the enzyme synthesis with 0.5%, 0.2% and 0.1% optimum concentrations. Dipotassium hydrogen phosphate (0.25%), potassium dihydrogen phosphate (0.05%), ammonium sulfate (0.05%) and calcium chloride (0.01%) were noticed as valuable salts to improve the production of enzyme. The thermophilic nature of isolate, with its broad pH stability profile and reduced fermentation time indicates its importance for effective xylan saccharification and for large scale production of endo-1,4-β-xylanase.

Keywords: geobacillus, optimization, production, xylanase

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Authors: Dorota M. Michalak

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The agricultural sector, due to the growing demand for food and over-exploitation of the natural environment, contributes to the deepening of climate change, on the one hand, and on the other hand, shrinking freshwater resources, as a negative effect of climate change, threaten the food security of each country. Therefore, adaptation measures to climate change should take into account effective water management and seek solutions ensuring food production at an unchanged or higher level, while not burdening the environment and not contributing to the worsening of the negative consequences of climate change. The problems of Poland's water management result not only from relatively small, natural water resources but to a large extent on the low efficiency of their use. Appropriate agricultural practices and state solutions in this field can contribute to achieving significant benefits in terms of economical water management in agriculture, providing a greater amount of water that could also be used for other purposes, including for purposes related to environmental protection. The aim of the article is to determine the level of use of water resources in Polish agriculture and the advancement of measures aimed at adapting Polish agriculture in the field of water management to climate change. The study provides knowledge about Polish legal regulations and water management tools, the shaping of water policy of Polish agriculture against the background of EU countries and other sources of energy, and measures supporting Polish agricultural holdings in the effective management of water resources run by state budget institutions. In order to achieve the above-mentioned goals, the author used research tools such as the analysis of existing sources and a survey conducted among five groups of entities, i.e. agricultural advisory centers and departments, agricultural, rural and environmental protection departments, regional water management boards, provincial agricultural chambers and restructuring and modernization of agriculture. The main conclusion of the analyses carried out is the low use of water in Polish agriculture in relation to other EU countries, other sources of intake in Poland, as well as irrigation. The analysis allows us to observe another problem, which is the lack of reporting and data collection, which is extremely important from the point of view of the effectiveness of adaptation measures to climate change. The results obtained from the survey indicate a very low level of support for government institutions in the implementation of adaptation measures to climate change and the water management of Polish farms. Some of the basic problems of the adaptation policy to change climate with regard to water management in Polish agriculture include a lack of knowledge regarding climate change, the possibilities of adapting, the available tools or ways to rationalize the use of water resources. It also refers to the lack of ordering procedures and the separation of responsibility with a proper territorial unit, non-functioning channels of information flow and practically low effects.

Keywords: water management, adaptation policy, agriculture, climate change

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Authors: J. E. O. Hernandez

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In the next 20 years, energy production by burning fuels will increase and so will the atmospheric concentration of CO2 and its well-known threats to life on Earth. The technologies available for capturing CO2 are still dubious and this keeps fostering an interest in bio-inspired approaches. The leading one is the application of carbonic anhydrase (CA) –a superfast biocatalyst able to convert up to one million molecules of CO2 into carbonates in water. However, natural CA underperforms when applied to real smoky CO2 in chimneys and, so far, the efforts to create superior CAs in the lab rely on screening methods running under pristine conditions at the micro level, which are far from resembling those in chimneys. For the evolution of man-made enzymes, selection rather than screening would be ideal but this is challenging because of the need for a suitable artificial environment that is also sustainable for our society. Herein we present the stepwise design and construction of a bioprocess (from bench-scale to semi-pilot) for evolutionary selection experiments. In this bioprocess, reaction and adsorption took place simultaneously at atmospheric pressure in a spray tower. The scrubbing solution was fed countercurrently by reusing municipal pressure and it was mainly prepared with water, carbonic anhydrase and calcium chloride. This bioprocess allowed for the enzymatic carbonation of smoky CO2; the reuse of process water and the recovery of solid carbonates without cooling of smoke, pretreatments, solvent amines and compression of CO2. The average yield of solid carbonates was 0.54 g min-1 or 12-fold the amount produced in serum bottles at lab bench scale. This bioprocess could be used as a tailor-made environment for driving the selection of superior CAs. The bioprocess and its match CA could be sustainably used to reduce global warming by CO2 emissions from exhausts.

Keywords: biological carbon capture and sequestration, carbonic anhydrase, directed evolution, global warming

Procedia PDF Downloads 193

Authors: Tadesse Eguale, Ephrem Engdawork, Wondwossen Gebreyes, Dainel Asrat, Hile Alemayehu, John Gunn

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Salmonella is one of the major zoonotic pathogens affecting wide range of vertebrates and humans worldwide. Consumption of contaminated dairy products and contact with dairy cattle represent the common sources of non-typhoidal Salmonella infection in humans. Fecal samples were collected from 132 dairy herds in central Ethiopia and cultured for Salmonella to determine the prevalence, serotype distribution and antimicrobial susceptibility. Salmonella was recovered from the feces of at least one cattle in 10(7.6%) of the dairy farms. Out of 1193 fecal samples 30(2.5%) were positive for Salmonella. Large farm size, detection of diarrhea in one or more animals during sampling and keeping animals completely indoor compared to occasional grazing outside were associated with Salmonella positivity of the farms. Farm level prevalence of Salmonella was significantly higher in young animals below 6 months of age compared to other age groups(X2=10.24; p=0.04). Nine different serotypes were isolated. The four most frequently recovered serotypes were S. Typhimurium (23.3%),S. Saintpaul (20%) and S. Kentucky and S. Virchow (16.7%) each. All isolates were resistant or intermediately resistant to at least one of the 18 drugs tested. Twenty-six (86.7%), 20(66.7%), 18(60%), 16(53.3%) of the isolates were resistant to streptomycin, nitrofurantoin, sulfisoxazole and tetracycline respectively. Resistance to 2 drugs was detected in 93.3% of the isolates. Resistance to 3 or more drugs were detected in 21(70%) of the total isolates while multi-drug resistance (MDR) to 7 or more drugs were detected in 12 (40%) of the isolates. The rate of occurrence of MDR in Salmonella strains isolated from dairy farms in Addis Ababa was significantly higher than those isolated from farms outside of Addis Ababa((p= 0.009). The detection of high MDR in Salmonella isolates originating from dairy farms warrants the need for strict pathogen reduction strategy in dairy cattle and spread of these MDR strains to human population.

Keywords: salmonella, antimicrobial resistance, fecal prevalence

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Authors: Ronel Solis, Leonardo Collado

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Migration law in the Republic of Panama has been regulated mainly by the executive branch. This has created a crisis not only institutional but also social because the evolution of these norms has rested greatly from the discretion of the government in office. This has created instability in immigration regulation and more now, with the migration crisis of which Panama is also part. Different migration policies have been established. The most recent is that of the controlled migration flow, in which, for humanitarian reasons, migrants move from the border with Colombia to the border with Costa Rica. Unfortunately, such control is not enough, and in some cases, unprotected migrants have been confined for months, their passports have been withheld, and no recognition of their rights is offered. The Inter-American Court of Human Rights has condemned Panama for the unfair detention of an irregular migrant, who was detained for two years in Panamanian prisons, without having committed a crime and without accessing a just defense. This is the case Vélez Loor vs. the Republic of Panama. Uncontrollable migration has been putting pressure on Panamanian public health services. The recent denunciation of HIV-related NGOs that warns that there are hundreds of foreigners who receive expensive antiretroviral therapy in Panama is serious, and several of them are irregular migrants. On the other hand, there are no border control posts with the Republic of Colombia, because it is a jungle area and migrants are exposed to arms and drug trafficking, and unfortunately, also to prostitution. Government entities such as the border police service have provided humanitarian support to migrants on the border with Colombia, although it is not their administrative function, and various entities discuss who should address this crisis. However, few economic resources are allocated by the government to solve this problem, especially with the recent mass migration of Venezuelans who have fled their country. The establishment of a migratory normative code is necessary to establish uniformity in the recognition and application of migratory rights. In this way, dependence on the changing migration policies of the different Panamanian governments would be eliminated, and the rights of migrants and nationals would be guaranteed.

Keywords: executive branch, irregular migration, migration code, Republic of Panama

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Authors: Indu Chauhan, Bhupendra S. Butola, Paritosh Mohanty

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It is very well known that properties of material changes as their size approach to nanoscale level due to the high surface area to volume ratio. However, in last few decades, a tenet ‘structure dictates function’ is quickly being adopted by researchers working with nanomaterials. The design and exploitation of nanoparticles with tailored shape and size has become one of the primary goals of materials science researchers to expose the properties of nanostructures. To date, various methods, including soft/hard template/surfactant assisted route hydrothermal reaction, seed mediated growth method, capping molecule-assisted synthesis, polyol process, etc. have been adopted to synthesize the nanostructures with controlled size and shape and monodispersity. However controlling the shape and size of nanoparticles is an ultimate challenge of modern material research. In particular, many efforts have been devoted to rational and skillful control of hierarchical and complex nanostructures. Thus in our research work, role of cellulose in manipulating the nanostructures has been discussed. Nanoparticles of α-Fe₂O₃ (diameter ca. 15 to 130 nm) were immobilized on the cellulose fiber surface by a single step in situ hydrothermal method. However, nanoflakes of α-FeOOH having thickness ca. ~25 nm and length ca. ~250 nm were obtained by the same method in absence of cellulose fibers. A possible nucleation and growth mechanism of the formation of nanostructures on cellulose fibers have been proposed. The covalent bond formation between the cellulose fibers and nanostructures has been discussed with supporting evidence from the spectroscopic and other analytical studies such as Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The role of cellulose in manipulating the nanostructures has been discussed.

Keywords: cellulose fibers, α-Fe₂O₃, α-FeOOH, hydrothermal, nanoflakes, nanoparticles

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Authors: Vinh Duy Cao, Shima Pilehvar, Anna M. Szczotok, Anna-Lena Kjøniksen

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The total energy consumption is dramatically increasing on over the world, especially for building energy consumption where a significant proportion of energy is used for heating and cooling purposes. One of the solutions to reduce the energy consumption for the building is to improve construction techniques and enhance material technology. Recently, microcapsulated phase change materials (MPCM) with high energy storage capacity within the phase transition temperature of the materials is a potential method to conserve and save energy. A new composite materials with high energy storage capacity by mixing MPCM into concrete for passive building technology is the promising candidate to reduce the energy consumption. One of the most untilized building materials for mixing with MPCM is Portland cement concrete. However, the emission of carbon dioxide (CO2) due to producing cement which plays the important role in the global warming is the main drawback of PCC. Accordingly, an environmentally friendly building material, geopolymer, which is synthesized by the reaction between the industrial waste material (aluminosilicate) and a strong alkali activator, is a potential materials to mixing with MPCM. Especially, the effect of MPCM on the thermal and mechanical properties of geopolymer concrete (GPC) is very limited. In this study, high thermal energy storage capacity materials were fabricated by mixing MPCM into geopolymer concrete. This article would investigate the effect of MPCM concentration on thermal and mechanical properties of GPC. The target is to balance the effect of MPCM on improving the thermal performance and maintaining the compressive strength of the geopolymer concrete at an acceptable level for building application.

Keywords: microencapsulated phase change materials, geopolymer concrete, energy storage capacity, thermal performance

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Authors: Hong-Min Kim, Da-Som Han, Myong-Hoon Lee

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CLCs (Cholesteric liquid crystals) draw tremendous interest due to their potential in various applications such as cholesteric color filters in LCD devices. CLC possesses helical molecular orientation which is induced by a chiral dopant molecules mixed with nematic liquid crystals. The efficiency of a chiral dopant is quantified by the HTP (helical twisting power). In this work, we designed and synthesized a series of new chiral dopants having a Schiff’s base imine structure with different alkyl chain lengths (butyl, hexyl and octyl) from chiral naphthyl amine by two-step reaction. The structures of new chiral dopants were confirmed by 1H-NMR and IR spectroscopy. The properties were investigated by DSC (differential scanning calorimetry calorimetry), POM (polarized optical microscopy) and UV-Vis spectrophotometer. These solid state chiral dopants showed excellent solubility in nematic LC (MLC-6845-000) higher than 17wt%. We prepared the CLC(Cholesteric Liquid Crystal) cell by mixing nematic LC (MLC-6845-000) with different concentrations of chiral dopants and injecting into the sandwich cell of 5μm cell gap with antiparallel alignment. The cholesteric liquid crystal phase was confirmed from POM, in which all the samples showed planar phase, a typical phase of the cholesteric liquid crystals. The HTP (helical twisting power) is one of the most important properties of CLC. We measured the HTP values from the UV-Vis transmittance spectra of CLC cells with varies chiral dopant concentration. The HTP values with different alkyl chains are as follows: butyl chiral dopant=29.8μm-1; hexyl chiral dopant= 31.8μm-1; octyl chiral dopant=27.7μm-1. We obtained the red, green and blue reflection color from CLC cells, which can be used as color filters in LCDs applications.

Keywords: cholesteric liquid crystal, color filter, display, HTP

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Authors: Mirko Ante, Şeniz Sörgel, Andreas Bund

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Li-S- (Lithium-Sulfur-) battery systems provide very high specific gravimetric energy (2600 Wh/kg) and volumetric energy density (2800Wh/l). Hence, Li-S batteries are one of the key technologies for both the upcoming electromobility and stationary applications. Furthermore, the Li-S battery system is potentially cheap and environmentally benign. However, the technical implementation suffers from cycling stability, low charge and discharge rates and incomplete understanding of the complex polysulfide reaction mechanism. The aim of this work is to develop an effective electrocatalyst for the polysulfide reactions so that the electrode kinetics of the sulfur half-cell will be improved. Accordingly, the overvoltage will be decreased, and the efficiency of the cell will be increased. An enhanced electroactive surface additionally improves the charge and discharge rates. To reach this goal, functionalized electrocatalytic coatings are investigated to accelerate the kinetics of the polysulfide reactions. In order to determine a suitable electrocatalyst, apparent exchange current densities of a variety of materials (Ni, Co, Pt, Cr, Al, Cu, ITO, stainless steel) have been evaluated in a polysulfide containing electrolyte by potentiodynamic measurements and a Butler-Volmer fit including diffusion limitation. The samples have been examined by Scanning Electron Microscopy (SEM) after the potentiodynamic measurements. Up to now, our work shows that cobalt is a promising material with good electrocatalytic properties for the polysulfide reactions and good chemical stability in the system. Furthermore, an electrodeposition from a modified Watt’s nickel electrolyte with a sulfur source seems to provide an autocatalytic effect, but the electrocatalytic behavior decreases after several cycles of the current-potential-curve.

Keywords: electrocatalyst, energy storage, lithium sulfur battery, sulfur electrode materials

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Authors: Seong Woon Lee, Soo Min Lim, Sung Sik Jeong, Jung Hoon Park

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The atmospheric concentration of greenhouse gas (GHG, Green House Gas) is increasing continuously as a result of the combustion of fossil fuels and industrial development. In response to this trend, many researches have been conducted on the reduction of GHG. Landfill gas (LFG, Land Fill Gas) is one of largest sources of GHG emissions containing the methane (CH₄) as a major constituent and can be considered renewable energy sources as well. In order to use LFG by connecting to the city pipe network, it required a process for removing impurities. In particular, oxygen must be removed because it can cause corrosion of pipes and engines. In this study, methane oxidation was used to eliminate oxygen from LFG and perovskite-type ceramic catalysts of La-Sr-Co-Fe-O composition was selected as a catalyst. Hollow fiber catalysts (HFC, Hollow Fiber Catalysts) have attracted attention as a new concept alternative because they have high specific surface area and mechanical strength compared to other types of catalysts. HFC was prepared by a phase-inversion/sintering technique using commercial La-Sr-Co-Fe-O powder. In order to measure the catalysts' activity, simulated LFG was used for feed gas and complete oxidation reaction of methane was confirmed. Pore structure of the HFC was confirmed by SEM image and perovskite structure of single phase was analyzed by XRD. In addition, TPR analysis was performed to verify the oxygen adsorption mechanism of the HFC. Acknowledgement—The project is supported by the ‘Global Top Environment R&D Program’ in the ‘R&D Center for reduction of Non-CO₂ Greenhouse gases’ (Development and demonstration of oxygen removal technology of landfill gas) funded by Korea Ministry of Environment (ME).

Keywords: complete oxidation, greenhouse gas, hollow fiber catalyst, land fill gas, oxygen removal, perovskite catalyst

Procedia PDF Downloads 117