Composite polyester membranes with embedded dendrimer hosts and bimetallic Fe/Ni nanoparticles: synthesis, characterisation and application to water treatment

Malinga, S. P.,Arotiba, O. A.,Krause, R. W. M.,Mapolie, S. F.,Diallo, M. S.,Mamba, B. B. Springer-Verlag 2013 Journal of nanoparticle research Vol.15 No.6

Removal of Cr(VI) from aqueous media using magnetic Co-reduced graphene oxide

Nduduzo Nkanyiso Malinga,Alan Lawrence Leigh Jarvis 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.11

The adsorption of Cr(VI) from an aqueous medium using magnetically functionalized cobalt nanoparticles- reduced graphene oxide (Co-rGO) was studied. Co-rGO was synthesized using the co-precipitation method. Graphene oxide and cobalt acetylacetonate were reduced together in water using sodium borohydride as a reducing agent. CorGO was used as the adsorbent material for the removal of dichromate ions in water. The prepared Co-rGO was characterized using powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Brunauer-Emmett- Teller (BET) surface area analysis. Selected area electron diffraction was used to determine that the cobalt nanoparticles were on the surface of the reduced graphene oxide. The effect of the mass of the adsorbent material (Co-rGO), the concentration and pH of the Cr(VI) containing solution and the time of contact between the adsorbent and the Cr(VI) on the adsorption efficiency were investigated. It was found that the optimum adsorbent mass for the efficient removal of Cr(VI) from a fixed concentration of Cr(VI) of 100mg L1 was 0.015 g, the optimum pH of the solution was 8, and the optimum contact time was 90 minutes. The experimental data obtained were fitted to the Langmuir, Freundlich, and Lui isotherms to obtain the characteristic parameters of each model. The experimental data fitted well to the Freundlich isotherm. The thermodynamic data was used to evaluate the nature of the adsorption. It was determined that the sorption process was physisorption. The kinetics of the adsorption process followed pseudo-second-order kinetic model.

The fatty acid composition of edible grasshopper Ruspolia differens (Serville) (Orthoptera: Tettigoniidae) feeding on diversifying diets of host plants

Karlmax RUTARO,Geoffrey M.MALINGA,Vilma J. LEHTOVAARA,Robert Opoke,Anu VALTONEN,Justus KWETEGYEKA,Philip Nyeko,Heikki ROININEN 한국곤충학회 2018 Entomological Research Vol.48 No.6

Ruspolia differens (Serville) (Orthoptera: Tettigoniidae) is a highly valued edible grasshopper species in Africa. However, the effects of plant diets on lipid content and fatty acid composition of R. differens are not well understood. We tested the effects of four diets on the total lipid content and fatty acid composition of R. differens. Sixth instar nymphs of R. differens were reared on one, and mixtures of two, three, and six natural plant inflorescences. Individuals collected from the field constituted a control treatment. We extracted lipids and analyzed the fatty acid methyl esters using gas chromatography–mass spectrometry. We analyzed if the total lipid content, body weight, and fatty acid composition differed among diets and between the sexes using two‐way ANOVAs and a PERMANOVA model, respectively. The total lipid content and weight of R. differens did not differ among the diets. The nine common fatty acids were palmitic (mean across treatments, 26%), oleic (22%), palmitoleic (18%), linoleic (13%), stearic (7%), myristic (6%), myristoleic (4%), α‐linolenic (2%) and arachidic acid (1%). The composition of fatty acids and the proportion of essential fatty acids significantly differed among the diets. The proportion of essential fatty acids was highest in the control treatment (21%) but low in less diversified (one to three feed) diets (12–13%). This study demonstrates that the fatty acid composition in R. differens can be influenced through diet. Thus, with dietary manipulations, using local plants in Africa, it is possible to produce R. differens with preferred high quality essential fatty acids for human consumption.

Artificial diets determine fatty acid composition in edible Ruspolia differens (Orthoptera: Tettigoniidae)

Karlmax Rutaro,Geoffrey M. Malinga,Robert Opoke,Vilma J. Lehtovaara,Francis Omujal,Philip Nyeko,Heikki Roininen,Anu Valtonen 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.4

There are increasing interests in rearing edible insects in Africa, but information on how the feeds modify their fatty acids is largely lacking. In this work, the influence of artificial diets on the fatty acid contents and composition in the edible Ruspolia differens (Serville, 1838), in Uganda was assessed. R. differens was reared on the mixtures of six gradually diversified diets of two, three, four, six, eight and nine feeds. The diets were formulated from rice seed head, finger millet seed head, wheat bran, superfeed chicken egg booster, sorghum seed head, germinated finger millet, simsim cake, crushed dog biscuit pellet and shea butter. Fatty acid methyl esters were prepared using direct transesterification method, and analysed using gas chromatography. The contents of saturated, monounsaturated and polyunsaturated fatty acid differed significantly among the diets. The more diverse diets resulted in increased content of the polyunsaturated fatty acids. The n6:n3 ratio differed significantly among the diets and between the sexes, with R. differens fed on the four-feed diet having a higher n6:n3 ratio than those fed on other diets. Also, the fatty acid composition differed significantly among the diets, and diet diversification corresponded with the proportions of polyunsaturated fatty acids, especially linoleic acid. Overall, our results demonstrate that higher levels of essential fatty acids can be achieved by rearing R. differens on highly diversified diets. These findings are important in informing the design of future mass-rearing program for this edible insect.

청소년들의 학업스트레스가 학교생활적응에 미치는 영향: 희망과 자아탄력성의 매개효과

안권순,강덕환,명향란,N.K.Bongobi,G.Umakanta,M.aqeel,D.M.S.Malinga,T.N.Belinda 한국청소년학회 2019 청소년학연구 Vol.26 No.6

The purpose of this paper is to examine the effects of youth's academic stress on school life adaptation, and to examine the mediation of hope and self-reliance. First, what are the differences in academic stress and hope, self-reliability, and school life adaptation? Second, what is the relationship between academic stress and hope, self-reliability and school life adaptation? Third, does hope mediate the relationship between school stress and school life adaptation? Fourth, does self-reliance mediate the relationship between academic stress and school life adaptation? The research tools of this study were the academic stress on school life adaptation, and to examine the mediation of hope and Ego-resilency Scale(ER), The data analysis was performed by variance analysis and regression analysis. The main conclusion of the study is that first, in academic stress and hope, self-discrimination and school life adaptation, adolescents experienced greater academic stress. Second, hope in academic stress and hope, self-discrimination and school life adaptation showed relation. This study suggest that the significance and implications of the study, as it has been found to reduce school life adaptabililty and academic stress in school life through the difference and influence of relevant variables of youth's academic stress and hope, self-reliability, self-dependence, self-distortion, and school life adaptation. 본 논문은 청소년들의 학교생활적응에 학업스트레스, 희망, 자아탄력성 등이 영향을 미치므로 청소년들의 학업스트레스가 학교생활적응에 어떻게 영향을 주는지를 알아보고 희망과 자아탄력성의 매개효과를 살펴보는데 연구의 필요성과 목적이 있다. 본 연구의 연구문제는 첫째, 학업스트레스, 학교생활적응, 희망 및 자아탄력성에 어떻한 차이와 관계가 있는가와 둘째, 희망과 자아탄력성은 학업스트레스와 학교생활적응 사이에서 매개하는가이다. 연구의 대상자는 청소년 554명(고등학생 389명, 중학생 165명)을 대상으로 하였다. 연구도구는 학업스트레스, 자아탄력성, 흐망 및 학교생활적응의 표준화된 설문지를 사용하였다. 본연구의 분석은 변량분석과 회귀분석을 사용하였다. 본 논문의 논의는 학교생활적응은 또래나 교사와 같은 학교 환경 안에서 관계하는 타인과의 관계에 잘 적응하고 이를 통해 자신의 성장을 도모할 수 있는 상황과 진로와 학업, 대인관계 등으로 인해 스트레스를 많이 받는 청소년에게 희망은 목표 달성을 위한 긍정적 신념으로서 어려움을 극복하고 잘 적응하도록 도와주는 힘이 되도록 하여야 한다. 본 논문은 다음과 같은 결론을 얻었다. 첫째, 학업스트레스에 대한 대처기술과 훈련이 필요하며 사회적 지지 등의 적극적인 스트레스 해소방법이 요구된다. 둘째, 청소년들이 호소하는 문제에 있어서 외부적 환경만을 생각하는 것이 아닌 내부적 요인인 희망을 살피고 청소년들의 효율적인 적응을 도와주는 개인상담이나 교육프로그램들이 필요하다고 본다. 셋째, 청소년들에게 우의, 상호친밀, 공감대, 정서적 및 사회적 갈등의 해결과 또래관계의 만족에 긍정적인 영향을 주기 때문에 자아탄력성을 증진시킬 필요성이 있다. 본 논문은 청소년의 학업스트레스와 희망, 자아탄력성 및 학교생활적응의 관련 변인들의 차이와 영향력을 밝힘으로서 학교생활적응과 스트레스를 줄일 수 있는 방안이 모색되어 생활지도나 상담 등에 활용되고 학교부적응 학생을 예방하는데 중요한 정보를 제공했다는데 연구의 의의와 시점이 있다고 하겠다.