5,028 research outputs found
Aplicación de EOMs y arcillas naturales para la eliminación de MCPD y EG de aceites comestibles
The aim of this study was to investigate the removal of 3-monochloropropane-1,2-diol (3-MCPD) and glycidyl esters (GEs) from edible oils by using Metal Organic Frameworks (MOF) and natural clays. First, the model oil was treated with adsorbents and titanium (IV) butoxide-terephthalate MOF (Ti-MOF) and kaolin were selected as the best performing MOF along with natural clay, respectively, for the removal of 3-MCPD and GEs. The effects of treatment conditions were also investigated, 6.0% adsorbent level, 120 min treatment time and 95 ºC temperature were determined to be the best treatment parameters. Finally, palm oil samples were treated with Ti-MOF and kaolin under the selected conditions and removal of 3-MCPD and GEs was obtained at up to 27% and 58%, respectively. In conclusion, MOFs and natural clays showed good potential for the removal of 3-MCPD and GEs, and the efficiency of the treatment can be improved by modifying the adsorbents.El objetivo de este estudio fue investigar la eliminación de 3-monocloropropano-1,2-diol (3-MCPD) y ésteres de glicidilo (EG) de aceites comestibles mediante el uso de estructuras orgánicas metálicas (EOMs) y arcillas naturales. El aceite modelo se trató en primer lugar con adsorbentes, se seleccionaron titanium (IV) tereftalato de butóxido (Ti-EOM) y caolín como EOM y arcilla natural, respectivamente, para el mejor rendimiento en la eliminación de 3-MCPD y EG. También se investigaron los efectos de las condiciones de tratamiento y se seleccionaron como los mejores parámetros un nivel de adsorbente de 6,0%, un tiempo de tratamiento de 120 min y temperatura de tratamiento de 95ºC. Finalmente, las muestras de aceite de palma se trataron con Ti-EOM y caolín en las condiciones seleccionadas y se obtuvo una eliminación de 3-MCPD y EG de hasta 27% y 58%, respectivamente. En conclusión, los EOMs y las arcillas naturales mostraron un buen potencial para la eliminación de 3-MCPD y EG, y la eficiencia del tratamiento se puede mejorar modificando los adsorbentes
Caracterización integral de las propiedades fisicoquímicas, térmicas, composicionales y sensoriales del aceite de semilla de rosa mosqueta prensado en frío
In this study, cold-pressed rosehip seed oil was fully characterized. Acidity and oxidation levels were near the limit values or slightly exceeded them and improvement in the storage conditions was suggested. The oil started to crystallize at -45.25 °C, and melt at -25.56 °C. Linoleic acid (51.1%), β-sitosterol (84.6%), γ-tocopherol (773.76 µg/g) and rosmarinic acid (31.38 µg/g) were determined as major fatty acid, sterol, tocopherol and phenolic compound, respectively. For the first time, aromatic volatile compounds and sensory descriptive terms were determined for cold-pressed rosehip seed oil. Sixty-seven volatile compounds were detected and L-limonene was found to be a major volatile compound. According to the sensory analysis, timber/kindling and raw vegetable tastes/aromas were found to be relatively dominant. Consequently, it is thought that rosehip seeds can be used as a raw material for edible and nutritionally-rich cold-pressed oil production and/or as source oil for functional food preparations.En este estudio se caracterizó completamente el aceite de semilla de rosa mosqueta prensado en frío. Los niveles de acidez y oxidación estaban cerca de los valores límite o los excedían ligeramente y se sugirió mejorar las condiciones de almacenamiento. El aceite comenzó a cristalizar a -45,25°C y a fundirse a -25,56°C. Se determinó el ácido linoleico (51,1%), β-sitosterol (84,6%), γ-tocoferol (773,76 µg/g) y ácido rosmarínico (31,38 µg/g) como principal ácido graso, esterol, tocoferol y compuesto fenólico, respectivamente. Por primera vez, se determinaron compuestos aromáticos volátiles y términos descriptivos sensoriales para el aceite de semilla de rosa mosqueta prensado en frío. Se detectaron sesenta y siete compuestos volátiles y se descubrió que el L-limoneno era un compuesto volátil importante. Según el análisis sensorial, se encontró que los sabores/aromas de madera/astillas y vegetales crudos eran relativamente dominantes. En consecuencia, se cree que las semillas de rosa mosqueta pueden usarse como materia prima para la producción de aceite prensado en frío comestible y nutritivo y/o como aceite fuente para preparaciones de alimentos funcionales
Data and evidence challenges facing place-based policing
PURPOSE: The purpose of this paper is to use an evaluation of a micro-place-based hot-spot policing implementation to highlight the potential issues raised by data quality standards in the recording and measurement of crime data and police officer movements. DESIGN/METHODOLOGY/APPROACH: The study focusses on an area of London (UK) which used a predictive algorithm to designate micro-place patrol zones for each police shift over a two-month period. Police officer movements are measured using GPS data from officer-worn radios. Descriptive statistics regarding the crime data commonly used to evaluate this type of implementation are presented, and simple analyses are presented to examine the effects of officer patrol duration (dosage) on crime in micro-place hot-spots. FINDINGS: The results suggest that patrols of 10-20 minutes in a given police shift have a significant impact on reducing crime; however, patrols of less than about 10 minutes and more than about 20 minutes are ineffective at deterring crime. RESEARCH LIMITATIONS/IMPLICATIONS: Due to the sparseness of officer GPS data, their paths have to be interpolated which could introduce error to the estimated patrol dosages. Similarly, errors and uncertainty in recorded crime data could have substantial impact on the designation of micro-place interventions and evaluations of their effectiveness. ORIGINALITY/VALUE: This study is one of the first to use officer GPS data to estimate patrol dosage and places particular emphasis on the issue of data quality when evaluating micro-place interventions
Nosocomial hepatitis C virus infection in a renal transplantation center
AbstractNosocomial hepatitis C virus (HCV) infections were recorded in the renal transplantation unit of the university hospital. There were cases of acute HCV infection with aggressive clinical courses diagnosed from a positive HCV RNA test in the early post-transplantation period and which remained anti-HCV negative. Their anti-HCV seronegativity was attributed to them having acquired HCV under intense immunosuppressive therapy and suggested that the aggressive clinical course could be due to the deficient immune response resulting in an inability to limit viral replication. There were also donors diagnosed as having acute HCV infection in the early post-operative period. Genotyping and sequence analysis for HCV were performed on the isolates of eight of these patients who were consecutively transplanted and of three donors whose recipients were infected with HCV prior to transplantation, and who acquired acute HCV infection after transplantation. Of the eight recipients in the first group three were genotype 1a, three were genotype 1b, one wasgenotype 3a, and the last one was genotype 4 according to Simmond's classification. Of the three donor-recipient couples both the HCV isolates from one couple were genotyped as 1b and the phylogenetic analysis indicated that the patients were infected with a common variant of HCV, but the genotypesof HCV isolates from the other couples were different. Recipients were genotype 1b and the donors were genotype 1a in these couples. Genotype results of the first group and donor-recipient couples, and sequence analysis of genotype 1b and 1a isolates, showed that the source of infection was not a unique strain and there were multiple breaks in universal precautions while managing these patients
Time-delayed Spatial Patterns in a Two-dimensional Array of Coupled Oscillators
We investigated the effect of time delays on phase configurations in a set of
two-dimensional coupled phase oscillators. Each oscillator is allowed to
interact with its neighbors located within a finite radius, which serves as a
control parameter in this study. It is found that distance-dependent
time-delays induce various patterns including traveling rolls, square-like and
rhombus-like patterns, spirals, and targets. We analyzed the stability
boundaries of the emerging patterns and briefly pointed out the possible
empirical implications of such time-delayed patterns.Comment: 5 Figure
Intrinsic Doping in Electrodeposited ZnS Thin Films for Application in Large-Area Optoelectronic Devices
Zinc sulphide (ZnS) thin films with both n- and p-type electrical conductivity were grown on glass/fluorine-doped tin oxide-conducting substrates from acidic and aqueous solution containing ZnSO4 and (NH4)2S2O3 by simply changing the deposition potential in a two-electrode cell configuration. After deposition, the films were characterised using various analytical techniques. X-ray diffraction analysis reveals that the materials are amorphous even after heat treatment. Optical properties (transmittance, absorbance and optical bandgap) of the films were studied. The bandgaps of the films were found to be in the range (3.68–3.86) eV depending on the growth voltage. Photoelectrochemical cell measurements show both n- and p-type electrical conductivity for the films depending on the growth voltage. Scanning electron microscopy shows material clusters on the surface with no significant change after heat treatment at different temperatures. Atomic force microscopy shows that the surface roughness of these materials remain fairly constant reducing only from 18 nm to 17 nm after heat treatment. Thickness estimation of the films was also carried out using theoretical and experimental methods. Direct current conductivity measurements on both as-deposited and annealed films show that resistivity increased after heat treatment
Repeatable and adjustable on-demand sciatic nerve block with phototriggerable liposomes
Pain management would be greatly enhanced by a formulation that would provide local anesthesia at the time desired by patients and with the desired intensity and duration. To this end, we have developed near-infrared (NIR) light-triggered liposomes to provide on-demand adjustable local anesthesia. The liposomes contained tetrodotoxin (TTX), which has ultrapotent local anesthetic properties. They were made photo-labile by encapsulation of a NIR-triggerable photosensitizer; irradiation at 730 nm led to peroxidation of liposomal lipids, allowing drug release. In vitro, 5.6% of TTX was released upon NIR irradiation, which could be repeated a second time. The formulations were not cytotoxic in cell culture. In vivo, injection of liposomes containing TTX and the photosensitizer caused an initial nerve block lasting 13.5 ± 3.1 h. Additional periods of nerve block could be induced by irradiation at 730 nm. The timing, intensity, and duration of nerve blockade could be controlled by adjusting the timing, irradiance, and duration of irradiation. Tissue reaction to this formulation and the associated irradiation was benign.National Institutes of Health (U.S.) (GM073626
Extended Formulations in Mixed-integer Convex Programming
We present a unifying framework for generating extended formulations for the
polyhedral outer approximations used in algorithms for mixed-integer convex
programming (MICP). Extended formulations lead to fewer iterations of outer
approximation algorithms and generally faster solution times. First, we observe
that all MICP instances from the MINLPLIB2 benchmark library are conic
representable with standard symmetric and nonsymmetric cones. Conic
reformulations are shown to be effective extended formulations themselves
because they encode separability structure. For mixed-integer
conic-representable problems, we provide the first outer approximation
algorithm with finite-time convergence guarantees, opening a path for the use
of conic solvers for continuous relaxations. We then connect the popular
modeling framework of disciplined convex programming (DCP) to the existence of
extended formulations independent of conic representability. We present
evidence that our approach can yield significant gains in practice, with the
solution of a number of open instances from the MINLPLIB2 benchmark library.Comment: To be presented at IPCO 201
- …