Eco-friendly facile synthesis of Co3O4-Pt nanorods for ethylene detection towards fruit quality monitoring

Ethylene, a biomarker widely employed for evaluating fruit ripening during storage, exists at extremely low concentrations. Therefore a gas sensor with high sensitivity and a sub-ppm detection limit is needed. In this work, porous Co3O4 nanorods were synthesized through a hydrothermal method involving Co(NO3)2, Na2C2O4, H2O and ethylene glycol (EG), followed by annealing at 400 degrees C in air. The surface of the porous Co3O4 nanorods was functionalized with Pt nanoparticles to enhance the ethylene sensing performance. The effect of Co3O4 surface functionalisation with Pt nanoparticles was investigated by adding different amounts of nanoparticles. The sensor's outstanding performance at the optimum working temperature of 250 degrees C is attributed to the synergy between the high catalytic activity of Pt nanoparticles and the extensive surface area of the porous Co3O4 nanorods. Compared to pure Co3O4, the 0.031 wt% Pt sensor showed better ethylene sensing performance with a response 3.4 times that of pristine Co3O4. The device also demonstrated high selectivity, repeatability, long-term stability and a detection limit of 0.13 ppm for ethylene, which is adequate for fruit quality monitoring. The gas sensing mechanism of porous Co3O4 nanorods and the influence of Pt decoration on sensor performance are discussed

COLOMBIAN EQUITY RETURN AND NARROW MONEY SUPPLY: AN ASYMMETRIC COINTEGRATION ANALYSIS

 ?The asymmetric, cointegrating relationship between the return on equity market and the narrowly defined money supply is documented. In fact, equity return and the monthly percentage change in the Colombian money supply M1 spread adjusts to the threshold value slower when a contractionary countercyclical policy action or an economic shock causes the money supply M1 to fall relative to the share price index, widening their spread, than when an expansionary countercyclical monetary policy action or a shock causes money supply M1 to move in the opposite direction, narrowing their spread. The empirical findings further indicate the impact lag on the Colombian monetary policy in the equity market is two years. These empirical findings should be of interest to both domestic and international investors who are interested in the Colombian equity market. The results also reveal the presence of both the neoclassical and the post-Keynesian positions on the relationship between equity return and money supply M1  Key words:  Asymmetry; return on equity market; money supply M1 ; TAR model; Colombia.  in the Colombian financial market. In the age of globalization, these findings may provide a better understanding of the impact of the countercyclical monetary policy on the equity market in Latin American economies

The Behaviors of Lending, Deposit Rates and Intermediation Premium of Pakistani Banks with Different Types of Ownership Structures

This study applies Enders and Siklos’ (2001) procedure to test for the long-run asymmetric co-integrating relationship and short-run dynamic Granger causality between Pakistani lending and deposit rates set by public, private, foreign, specialized, and all banks combined over the period January 2004 to December 2013. Terrorist activities on the money market plays negative role. The empirical results suggest a long-run asymmetric co-integration relationship between the rates. The Granger causality tests suggest bidirectional and asymmetric causality between lending and deposit rates set by Pakistani public and private banks, while the lending rates set by the country’s foreign, specialized and all banks combined are exogenous from their deposit rates.  The unusually fast and overshot adjustments of the lending rates in response to increases in the intermediation premium of public banks are interpreted as graft maximization.  The asymmetric and different nature of the Granger causalities exhibited by banks with different ownership structures should be of special interest for the Central Bank in formulating and implementing its countercyclical monetary policy and for corporations in determining their capital structures

CONTAGION OF US SUBPRIME MORTGAGE CRISIS TO COLOMBIAN ECONOMY: MEASURED BY FINANCIAL MARKET DATA

The long-horizon event study methodology is used to document the severe impact of the US subprime mortgage crisis on the Colombian economy. The estimated parameter of a constantmean return model is used to derive the “abnormal return” on the market portfolios of Colombia over its selected event window. Analyses of the results reveal that the US subprime mortgage crisis negatively affected both the Colombian and the US equity markets almost identically in terms of cumulative percentage reductions and timing. Statistic testing results seem to support the qualitative observation. This phenomenon can be attributable to the recent multilateral and regional trade agreements that increase the flow of trade and foreign direct investment to Colombia.El estudio metodológico de horizonte largo es usado para documentar el impacto severo de la crisis de la finca raíz de Estados Unidos en la Economía Colombiana. El parámetro estimado de la constante del retorno del modelo es usado para derivar el retorno anormal en el mercado de portafolios sobre su selección de la ventana de evento. Análisis de estos resultados revelan que la crisis de la finca raíz en Estados Unidos afectó negativamente ambos mercados de acciones en Estados Unidos y Colombia casi idénticamente en términos de reducción de porcentaje cumulativo y tiempo. Resultados de pruebas estadísticas parecen soportar la observación. Este fenómeno puede ser atribuido a los recientes acuerdos de comercio multilaterales y regionales que incrementan el flujo de comercio e inversión extranjera directa a Colombia

Inverse kinematic control algorithm for a welding robot - positioner system to trace a 3D complex curve

The welding robots equipped with rotary positioners have been widely used in several manufacturing industries. However, for welding a 3D complex weld seam, a great deal of points should be created to ensure the weld path smooth. This is a boring job and is a great challenge - rotary positioner system since the robot and the positioner must move simultaneously at the same time. Therefore, in this article, a new inverse kinematics solution is proposed to generate the movement codes for a six DOFs welding robot incorporated with a rotary positioner. In the algorithm, the kinematic error is minimized, and the actual welding error is controlled so that it is always less than an allowable limit. It has shown that the proposed algorithm is useful in developing an offline CAD-based programming tool for robots when welding complex 3D paths. The use of the algorithm increases the accuracy of the end-effector positioning and orientation, and reduces the time for teaching a welding robot - positioner system. Simulation scenarios demonstrate the potency of the suggested method

Prevalence and Determinants of Medication Adherence among Patients with HIV/AIDS in Southern Vietnam

This study was conducted to determine the prevalence and determinants of medication adherence among patients with HIV/AIDS in southern Vietnam. METHODS: A cross-sectional study was conducted in a hospital in southern Vietnam from June to December 2019 on patients who began antiretroviral therapy (ART) for at least 6 months. Using a designed questionnaire, patients were considered adherent if they took correct medicines with right doses, on time and properly with food and beverage and had follow-up visits as scheduled. Multivariable logistic regression was used to identify determinants of adherence. KEY FINDINGS: A total of 350 patients (from 861 medical records) were eligible for the study. The majority of patients were male (62.9%), and the dominant age group (≥35 years old) accounted for 53.7% of patients. Sexual intercourse was the primary route of transmission of HIV (95.1%). The proportions of participants who took the correct medicine and at a proper dose were 98.3% and 86.3%, respectively. In total, 94.9% of participants took medicine appropriately in combination with food and beverage, and 75.7% of participants were strictly adherent to ART. The factors marital status (odds ratio (OR) = 2.54; 95%CI = 1.51-4.28), being away from home (OR = 1.7; 95%CI = 1.03-2.78), substance abuse (OR = 2.7; 95%CI = 1.44-5.05), general knowledge about ART (OR = 2.75; 95%CI = 1.67-4.53), stopping medication after improvement (OR = 4.16; 95%CI = 2.29-7.56) and self-assessment of therapy adherence (OR = 9.83; 95%CI = 5.44-17.77) were significantly associated with patients' adherence. CONCLUSIONS: Three-quarters of patients were adherent to ART. Researchers should consider these determinants of adherence in developing interventions in further studies