1,020 research outputs found

    Biosorption of Pb and Cu from aqueous solution using banana peel powder

    Get PDF
    Banana peel is considered as a dominant agricultural waste which causes more disposal problem everywhere. This disposal problem could be handled by changing it into an advantage whereby utilizing banana peel to be used as an adsorbent to remove heavy metals from water. Based on the above perspectives, an adsorption capability of banana peel was evaluated in removing toxic heavy metals Pb and Cu from aqueous solution. The banana peel was chemically modified (BPPT) by treating it with 0.1 M sodium hydroxide to examine the improvement in the adsorption capacity compared to the untreated form (BPPU). The parameters such as adsorbent mass, initial pH, initial concentration and contact time were tested accordingly. The adsorbent mass with the highest adsorption capacity for both Pb and Cu were 0.9 g. As for the effect of pH, adsorption of Pb and Cu was favourable at pH 7 and pH 9, respectively. The effects of concentration and contact time on peel extract, the maximum adsorption for Pb has shown at 4 mg/L at 120 min for BPPU and was 6 mg/L at 150 min for BPPT. As for Cu, both untreated and treated adsorbent achieved the highest adsorption rate at concentration of 2 mg/L with contact time at 120 min. Atomic absorption spectrophotometer (AAS) was used to measure the concentration of toxic metals. Scanning electron microscope was used to observe the differences in morphology of the peel between BPPT and BPPU before and after adsorption. Fourier transform infrared spectroscopy was used to determine the functional groups present in it which was responsible for the adsorption process. Equilibrium data of both metals were well fitted with the Langmuir and Freundlich isotherm models with (R2 ≈ 0.99). RL values for both Pb and Cu also ranged in between 0 and 1 indicating a favourable adsorption process based on the Langmuir isotherm. Overall BPPT proved to have higher adsorption capacity than BPPU. BPPT gives the highest maximum coverage capacity (Qo) for Pb adsorption with 89.286 and 5.720 mg/g for Cu in a favourable condition. Therefore, it could be concluded that banana peel could be recognized as potential and environmentally friendly agro-based waste material which could be utilized as low-cost adsorbents to remove toxic metal from industrial wastewater

    Electrocardiographic Abnormalities Among Arsenic-exposed Persons Through Groundwater in Bangladesh

    Get PDF
    This study was carried out among arsenic-exposed and non-exposed people of Bangladesh to assess and compare their cardiac status based on electrocardiographic (ECG) findings. For the purpose of the study, participants were included in three groups: arsenic-exposed persons with arsenicosis (arsenicosis group), arsenic-exposed persons without arsenicosis (non-arsenicosis group), and persons not exposed to arsenic (non-exposed group). Each group included 50 respondents. In this study, no significant difference in heart rate, rhythm, axis, and pulse rate interval was detected among the arsenicosis, non-arsenicosis and non-exposed groups. A significant difference in corrected QT interval between the arsenicosis and the non-exposed group (p<0.05) was observed. On the contrary, no statistically significant difference in corr-ected QT interval between the non-arsenicosis and the non-exposed group was found. Abnormal QRS complex was found among 14%, 8%, and 2% of the arsenicosis, non-arsenicosis, and non-exposed groups respectively. ECG findings, indicative of left ventricular hypertrophy, ischaemic heart disease, andright bundle branch block, were high among the arsenicosis group. Overall, abnormal ECG findings were high (58%) among the respondents of the arsenicosis group and were highly significant (p<0.001). The findings revealed that there was a significant association between ECG abnormalities and arsenic exposure

    Particle formation and micronization using non-conventional techniques- review

    Get PDF
    Due to growing concerns regarding health, safety and the environment, non-conventional methods for particle formation and micronization that are either solvent-less or use environmentally acceptable solvents such as carbon dioxide have come into favor. Supercritical CO2 (sc CO2) (T > 31.1 'C, P > 7.3 MPa) has been used in food and pharmaceutical industries to minimize the use of organic solvents, produce new food products, produce environmentally superior food products and to process and micronize (0.1–5mm) pharmaceuticals. Control of particle size increases the dissolution rate of drugs into the body. Techniques that use sc CO2 eliminate inherent drawbacks of conventional methods such as thermal or mechanical degradation of the product, poor control of the particle size and morphology, lack of brittleness of some polymers and low encapsulation efficiency. Severaltechniques have been reported for the particle formation and micronization using supercritical fluids that have been successfully scaled up for commercial use. Supercritical CO2 has also been used to develop applications for medicines, essential oils, vitamins, food grade polymers, catalysts and pigments. This review highlights the process mechanism of supercritical fluid based techniques as well as some applications on particle formation and micronization

    The use of medicinal plants in health care practices by Rohingya refugees in a degraded forest and conservation area of Bangladesh

    Get PDF
    People in developing countries traditionally rely on plants for their primary healthcare. This dependence is relatively higher in forests in remote areas due to the lack of access to modern health facilities and easy availability of the plant products.We carried out an ethno-medicinal survey in Teknaf Game Reserve (TGR), a heavily degraded forest and conservation area in southern Bangladesh, to explore the diversity of plants used by Rohingya refugees for treating various ailments. The study also documented the traditional utilization, collection and perceptions of medicinal plants by the Rohingyas residing on the edges of this conservation area. We collected primary information through direct observation and by interviewing older respondents using a semi-structured questionnaire. A total of 34 plant species in 28 families were frequently used by the Rohingyas to treat 45 ailments, ranging from simple headaches to highly complex eye and heart diseases. For medicinal preparations and treating various ailments, aboveground plant parts were used more than belowground parts. The collection of medicinal plants was mostly from the TGR. © 2009 Taylor & Francis

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

    Full text link
    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

    Get PDF
    Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

    Get PDF
    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

    Get PDF
    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

    Full text link
    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

    Get PDF
    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI
    corecore