57 research outputs found
Efficient Catalytic Production Of Biodiesel Using Nano-sized Sugar Beet Agro-industrial Waste
This paper addresses the use of agro-industrial residue as a promising heterogeneous catalyst for the efficient production of biodiesel. That is, CaO-rich Sugarbeet agro-industrial waste (smashed down to nano-size) shows superb catalytic activity for biodiesel production via transesterification process employing sunflower oil and methanol. Physicochemical properties of the proposed catalyst are probed by TGA–DTG, XRF, XRD, FT-IR, SEM, BET, and CO2-TPD techniques. Biodiesel conversion (%) of Ca. 93% is achieved under the optimal conditions (catalyst loading of 1 wt%, methanol/oil molar ratio of 4.5:1, refluxed at 75 °C for 60 min). The relatively short reaction time indicates the enhanced kinetics of the process using the proposed agro-industrial residue which imparts its economic feasibility. Also, the proposed CaO-rich residue can be reused twice while retaining its catalytic activity. The thus-produced biodiesel fuel compiles the ASTM D6751 and EN-14214 specifications
Inner-sphere oxidation of ternary iminodiacetatochromium(III) complexes involving DL-valine and L-arginine as secondary ligands. Isokinetic relationship for the oxidation of ternary iminodiacetato-chromium(III) complexes by periodate
<p>Abstract</p> <p>Background</p> <p>In this paper, the kinetics of oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>and [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>(HIDA = iminodiacetic acid, Val = DL-valine and Arg = L-arginine) were studied. The choice of ternary complexes was attributed to two considerations. Firstly, in order to study the effect of the secondary ligands DL-valine and L-arginine on the stability of binary complex [Cr<sup>III</sup>(HIDA)(IDA)(H<sub>2</sub>O)] towards oxidation. Secondly, transition metal ternary complexes have received particular focus and have been employed in mapping protein surfaces as probes for biological redox centers and in protein capture for both purification and study.</p> <p>Results</p> <p>The results have shown that the reaction is first order with respect to both [IO<sub>4</sub><sup>-</sup>] and the complex concentration, and the rate increases over the pH range 2.62 – 3.68 in both cases. The experimental rate law is consistent with a mechanism in which both the deprotonated forms of the complexes [Cr<sup>III</sup>(IDA)(Val)(H<sub>2</sub>O)<sub>2</sub>] and [Cr<sup>III</sup>(IDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>] are significantly more reactive than the conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>, <it>k</it><sub>3 </sub>(1.82 × 10<sup>-3 </sup>s<sup>-1</sup>), is greater than the value of <it>k</it><sub>1 </sub>(1.22 × 10<sup>-3 </sup>s<sup>-1</sup>) for the oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>at 45.0°C and <it>I </it>= 0.20 mol dm<sup>-3</sup>. It is proposed that electron transfer proceeds through an inner-sphere mechanism <it>via </it>coordination of IO<sub>4</sub><sup>- </sup>to chromium(III).</p> <p>Conclusion</p> <p>The oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>and [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+ </sup>by periodate may proceed through an inner-sphere mechanism via two electron transfer giving chromium(VI). The value of the intramolecular electron transfer rate constant for the oxidation of [Cr<sup>III</sup>(HIDA)(Arg)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>, <it>k</it><sub>3</sub>, is greater than the value of <it>k</it><sub>1 </sub>for the oxidation of [Cr<sup>III</sup>(HIDA)(Val)(H<sub>2</sub>O)<sub>2</sub>]<sup>+</sup>. A common mechanism for the oxidation of ternary iminodiacetatochromium(III) complexes by periodate is proposed, and this is supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions.</p
Development and implementation of guidelines for the management of depression: a systematic review
Objective: To evaluate the development and implementation of clinical practice guidelines for the management of depression globally. Methods: We conducted a systematic review of existing guidelines for the management of depression in adults with major depressive or bipolar disorder. For each identified guideline, we assessed compliance with measures of guideline development quality (such as transparency in guideline development processes and funding, multidisciplinary author group composition, systematic review of comparative efficacy research) and implementation (such as quality indicators). We compared guidelines from low- and middle-income countries with those from high-income countries. Findings: We identified 82 national and 13 international clinical practice guidelines from 83 countries in 27 languages. Guideline development processes and funding sources were explicitly specified in a smaller proportion of guidelines from low- and middle-income countries (8/29; 28%) relative to high-income countries (35/58; 60%). Fewer guidelines (2/29; 7%) from low- and middle-income countries, relative to high-income countries (22/58; 38%), were authored by a multidisciplinary development group. A systematic review of comparative effectiveness was conducted in 31% (9/29) of low- and middle-income country guidelines versus 71% (41/58) of high-income country guidelines. Only 10% (3/29) of low- and middle-income country and 19% (11/58) of high-income country guidelines described plans to assess quality indicators or recommendation adherence. Conclusion: Globally, guideline implementation is inadequately planned, reported and measured. Narrowing disparities in the development and implementation of guidelines in low- and middle-income countries is a priority. Future guidelines should present strategies to implement recommendations and measure feasibility, cost-effectiveness and impact on health outcomes
Kinetics and mechanism of oxidation of chromium(III)-L-glutamic acid complex by periodate
410-414The kinetics
of oxidation of the chromium(III)-L-glutamic acid complex, [CrIII(L)2(H2O)2]+
, by periodate in aqueous solutions has been found to obey the following-equation:
d[CrVI]/dt=k2K5[CrIII]T[IVII]
T /{1+([H+]/K1)+K5[IVII]
T}
where k2
is the rate constant for the electron transfer process, K1the
equilibrium constant for dissociation of [CrIII(L)2 (H2O)2+]
to of [CrIII(L)2 (H2O)(OH)] + H+, and
K5 the pre-equilibrium formation constant. Values of k2
= 2.93Ă—10-3 s-1,K1 = 6.26 Ă—10-4
mol dm-3 and K5 = 88.41 dm3 mol-1
have been obtained at 30°C and I= 0.2 mol dm-3 . Thermodynamic
activation parameters have been calculated. It is proposed that electron transfer
proceeds through an inner-sphere mechanism via coordination of IO4-
to chromium(III)
Inner-sphere Oxidation of a Ternary Complex Involving Iminodiacetatochromium(III) and DL-Aspartic acid by Periodate
Kinetic and mechanism of the oxidation of chromium(III) complex with anthranil-N,N-diacetic acid by periodate ion in acidic aqueous solutions
Impact of Clinical Pilates Exercise on Pain, Cardiorespiratory Fitness, Functional Ability, and Quality of Life in Children with Polyarticular Juvenile Idiopathic Arthritis
Objective: This study intended to examine the effects of Pilates exercise on pain, cardiorespiratory fitness, functional ability, and quality of life in children with polyarticular juvenile idiopathic arthritis. Methods: Forty children with polyarticular JIA aged 10–14 years old were randomly allocated into two groups: the control group (n = 20) received conventional physical therapy (CPT), and the experimental group (n = 20) received clinical Pilates exercises combined with CPT. Patients in both groups received their program three times/week for 3 months. Pain, cardiorespiratory fitness, functional ability, and quality of life were assessed through the visual analogue scale, cardiopulmonary exercise test, 6 min walk test, and PedsQL scale, respectively, just before and after treatment. Results: Pain (p = 0.001), cardiorespiratory markers (all p < 0.05), functional ability (p = 0.002), and overall quality of life (p = 0.007) improved significantly in the experimental groups compared to the control group. Conclusion: Incorporating Pilates exercises into CPT is likely more effective for decreasing pain intensity, improving cardiorespiratory fitness, augmenting functional ability, and promoting quality of life in children with JIA than CPT alone
Kinetics and Mechanism of Oxidation of a Ternary Complex Involving Dipicolinatochromium(III) and Proline by N-bromsuccinimide
The Kinetics and Mechanism of Oxidation of Triethylenetetraaminehexaacetatocobaltate(II) Complex by Periodate Ion in AqueousMedium
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